WorldWideScience

Sample records for crop residue removal

  1. Electrolytic Removal of Nitrate From CELSS Crop Residues

    Science.gov (United States)

    Colon, Guillermo; Sager, John

    1996-01-01

    The controlled ecological life support system (CELSS) resource recovery system is a waste processing system using aerobic and anaerobic bioreactors to recover plant nutrients and secondary foods from inedible biomass. Crop residues contain significant amounts of nitrate which presents two problems: (1) both CELSS biomass production and resource recovery consume large quantities of nitric acid, (2) nitrate causes a variety of problems in both aerobic and anaerobic bioreactors. A technique was proposed to remove the nitrate from potato inedible biomass leachate and to satisfy the nitric acid demand using a four compartment electrolytic cell.

  2. How does crop residue removal affect soil organic carbon and yield? A hierarchical analysis of management and environmental factors

    NARCIS (Netherlands)

    Warren Raffa, D.; Bogdanski, A.; Tittonell, P.

    2015-01-01

    The current advancement of the bioenergy sector along with the need for sustainable agricultural systems call for context-specific crop residue management options - implying variable degrees of removal - across climatic regions, soil types and farming systems around the world. A large database

  3. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    Science.gov (United States)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

  4. Adsorptive Removal of Trichloroethylene in Water by Crop Residue Biochars Pyrolyzed at Contrasting Temperatures: Continuous Fixed-Bed Experiments

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2015-01-01

    Full Text Available Biochar (BC has attracted great attention as an alternative sorbent to activated carbon (AC. Objective of this study was to determine trichloroethylene (TCE removal by soybean stover BC pyrolyzed at 300 (BC300 and 700°C (BC700 in continuous fixed-bed column. Columns packed with BC300, BC700, and AC reached breakthrough time in 1.1, 27.0, and 50.7 h, respectively. BC700 had higher TCE adsorption capacity than BC300 due to its higher surface area, nonpolarity, and aromaticity. The sorption capacities of AC (774.0 mg g−1 and BC700 (515.1 mg g−1 were 21.6 and 14.4 times higher than that of BC300 (35.9 mg g−1. The lower desorption rate of TCE from BC300 than BC700 and AC may be attributed to the strong binding/partition of TCE to the noncarbonized part of BC. Thomas model also adequately described the adsorption data indicating interphase mass transfer. Overall, AC showed best efficiency for removing TCE from water in column experiments. However, although sorption and desorption capabilities of BC700 were a little lower than AC, it is still a good alternative for AC to remove organic contaminants such as TCE from water due to its cost-effectiveness.

  5. Ammonia emission from crop residues : quantification of ammonia volatilization based on crop residue properties

    NARCIS (Netherlands)

    Ruijter, de F.J.; Huijsmans, J.F.M.

    2012-01-01

    This paper gives an overview of available literature data on ammonia volatilization from crop residues. From these data, a relation is derived for the ammonia emission depending on the N-content of crop residue.

  6. Nitrogen acquisition by pea and barley and the effect of their crop residues on available nitrogen for subsequent crops

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1996-01-01

    using N-15-labelled residues. Field pea fixed 75% of its N requirement and the N-2 fixation almost balanced the N removed with the seeds. The barley crop recovered 80% of the N-15-labelled fertilizer N supplied and the N in the barley grain corresponded to 80% of the fertilizer N taken up by the crop....... In the short term, the incorporation of crop residues was not important in terms of contributing N to the subsequent crop compared to soil and fertilizer N sources, but residues improved the conservation of soil N in the autumn. In the long-term, crop residues are an important factor in maintaining soil...

  7. Recycling crop residues for use in recirculating hydroponic crop production

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Sager, J. C.

    1996-01-01

    As part of bioregenerative life support feasibility testing by NASA, crop residues are being used to resupply elemental nutrients to recirculating hydroponic crop production systems. Methods for recovering nutrients from crop residues have evolved from water soaking (leaching) to rapid aerobic bioreactor processing. Leaching residues recovered the majority of elements but it also recovered significant amounts of soluble organics. The high organic content of leachates was detrimental to plant growth. Aerobic bioreactor processing reduced the organic content ten-fold, which reduced or eliminated phytotoxic effects. Wheat and potato production studies were successful using effluents from reactors having with 8- to 1-day retention times. Aerobic bioreactor effluents supplied at least half of the crops elemental mass needs in these studies. Descriptions of leachate and effluent mineral content, biomass productivity, microbial activity, and nutrient budgets for potato and wheat are presented.

  8. Evaluation of Crops Sensitivity to Atrazine Soil Residual

    Directory of Open Access Journals (Sweden)

    E Izadi

    2012-02-01

    Full Text Available Abstract In order to study the sensitivity of 9 crops to atrazine soil residual, two separate experiments were conducted in field and greenhouse conditions. First experiment was conducted in a field with treated soil by atrazine based on split plot and the results evaluated in greenhouse conditions. Treatments in the field experiment included two organic manure application rates (0 and 50 t/ha as main plots and 2 atrazine application rates (2 and 4 kg/ha atrazine a.i. as sob plots. After corn harvesting soil was sampled at 0-15 cm surface layer in each plots in 15 points, after mixing the samples. Wheat, barley, sugar beet, pea, lens and colza planted in pots at greenhouse. Second experiment conducted in greenhouse conditions for evaluation of atrazine soil residual in completely randomized design. Treatments included atrazine soil residual concentrations (0, 0.2, 0.5, 1, 5, 10 and 15 mg/kg soil and crops included wheat, barley, sugar beet, pea, lens, rape, bean and tomato. Results showed that atrazine residue had no effect on crops growth in field experiment treated with atrazine. It seems that atrazine residue in filed soil is lower that its damage threshold for crops or maybe for its fast removal in field than in control conditions. But in bioassay experiment (greenhouse experiment crops response to atrazine residues were different. Results showed that onion and pea were most susceptible ant tolerant crops between studied species and based of ED50 parameter the other crops tolerance to total residue ranked as: pea< bean< lentil< sugar beet< tomato< barley< wheat< rape< onion. Keywords: Atrazine residue, Pea, Bean, Lentil, Sugar beet, Barley, Wheat, Rape, Tomato

  9. Agricultural Residues and Biomass Energy Crops

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    There are many opportunities to leverage agricultural resources on existing lands without interfering with production of food, feed, fiber, or forest products. In the recently developed advanced biomass feedstock commercialization vision, estimates of potentially available biomass supply from agriculture are built upon the U.S. Department of Agriculture’s (USDA’s) Long-Term Forecast, ensuring that existing product demands are met before biomass crops are planted. Dedicated biomass energy crops and agricultural crop residues are abundant, diverse, and widely distributed across the United States. These potential biomass supplies can play an important role in a national biofuels commercialization strategy.

  10. Biomass energy from crop and forest residues.

    Science.gov (United States)

    Pimentel, D; Moran, M A; Fast, S; Weber, G; Bukantis, R; Balliett, L; Boveng, P; Cleveland, C; Hindman, S; Young, M

    1981-06-05

    Residues remaining after the harvest of crop and forestry products are being proposed as a substantial energy source for the nation. An estimated 22 percent of the residues might be utilized, providing a renewable source of high-grade energy with the potential of supplying 1 percent of the current U.S. gasoline consumption as ethanol or 4 percent of the total electrical energy used. These net energy benefits are limited by high energy costs to collect, transport, and process the residues. Environmental threats include soil erosion, water runoff, and nutrient loss.

  11. Liquefaction of crop residues for polyol production

    OpenAIRE

    Wan, C.; Wang, T.; Zhang, L.; Zang, L.; Li, Y; Mao, Z.; Liang, L.

    2006-01-01

    The liquefaction of crop residues in the presence of ethylene glycol, ethylene carbonate, or polyethylene glycol using sulfuric acid as a catalyst was studied. For all experiments, the liquefaction was conducted at 160C and atmospheric pressure. The mass ratio of feedstock to liquefaction solvents used in all the experiments was 30:100. The results show that the acid catalyzed liquefaction process fit a pseudo-first-order kinetics model. Liquefaction yields of 80, 74, and 60% were obtained i...

  12. Crop residues as soil amendments and feedstock for bioethanol production.

    Science.gov (United States)

    Lal, R

    2008-01-01

    Traditional solid fuels account for more than 90% of the energy supply for 3 billion people in developing countries. However, liquid biofuels (e.g., ethanol) are perceived as an important alternative to fossil fuel. Global crop residue production is estimated at about 4 billion Mg for all crops and 3 billion Mg per annum for lignocellulosic residues of cereals. One Mg of corn stover can produce 280L of ethanol, compared with 400L from 1Mg of corn grains; 1Mg of biomass is also equivalent to 18.5GJ of energy. Thus, 3 billion Mg of residues are equivalent to 840 billion L of ethanol or 56x10(9)GJ of energy. However, removal of crop residues exacerbates soil degradation, increases net emission of CO2, and aggravates food insecurity. Increasing the SOC pool by 1 Mg C ha(-1)yr(-1) through residue retention on soil can increase world food grain production by 24-40 million Mg yr(-1), and root/tuber production by 6-11 million Mg yr(-1). Thus, identifying alternate sources of biofuel feedstock (e.g., biofuel plantations, animal waste, municipal sold waste) is a high priority. Establishing biofuel plantations on agriculturally marginal or degraded lands can off-set 3.5-4 Pg Cyr(-1).

  13. Hydroponic Crop Production using Recycled Nutrients from Inedible Crop Residues

    Science.gov (United States)

    Garland, Jay L.; Mackowiak, Cheryl L.; Sager, John C.

    1993-01-01

    The coupling of plant growth and waste recycling systems is an important step toward the development of bioregenerative life support systems. This research examined the effectiveness of two alternative methods for recycling nutrients from the inedible fraction (residue) of candidate crops in a bioregenerative system as follows: (1) extraction in water, or leaching, and (2) combustion at 550 C, with subsequent reconstitution of the ash in acid. The effectiveness of the different methods was evaluated by (1) comparing the percent recovery of nutrients, and (2) measuring short- and long-term plant growth in hydroponic solutions, based on recycled nutrients.

  14. Soil residual nitrogen under various crop rotations and cultural practices

    Science.gov (United States)

    Crop rotation and cultural practice may influence soil residual N available for environmental loss due to crop N uptake and N immobilization. We evaluated the effects of stacked vs. alternate-year crop rotations and cultural practices on soil residual N (NH4-N and NO3-N contents) at the 0-125 cm dep...

  15. Liquefaction of crop residues for polyol production

    Directory of Open Access Journals (Sweden)

    Wan, C.

    2006-11-01

    Full Text Available The liquefaction of crop residues in the presence of ethylene glycol, ethylene carbonate, or polyethylene glycol using sulfuric acid as a catalyst was studied. For all experiments, the liquefaction was conducted at 160C and atmospheric pressure. The mass ratio of feedstock to liquefaction solvents used in all the experiments was 30:100. The results show that the acid catalyzed liquefaction process fit a pseudo-first-order kinetics model. Liquefaction yields of 80, 74, and 60% were obtained in 60 minutes of reaction when corn stover was liquefied with ethylene glycol, a mixture of polyethylene glycol and glycerol (9:1, w/w, and ethylene carbonate, respectively. When ethylene carbonate was used as solvent, the liquefaction yields of rice straw and wheat straw were 67% and 73%, respectively, which is lower than that of corn stover (80%. When a mixture of ethylene carbonate and ethylene glycol (8:2, w/w was used as solvent, the liquefaction yields for corn stover, rice straw and wheat straw were 78, 68, and 70%, respectively.

  16. Cover crop residue management for optimizing weed control

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2009-01-01

    Although residue management seems a key factor in residue-mediated weed suppression, very few studies have systematically compared the influence of different residue management strategies on the establishment of crop and weed species. We evaluated the effect of several methods of pre-treatment and p

  17. Effect of crop residue harvest on long-term crop yield, soil erosion, and carbon balance: tradeoffs for a sustainable bioenergy feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, Jay S.; Izaurralde, Roberto C.

    2010-08-26

    Agricultural residues are a potential feedstock for bioenergy production, if residue harvest can be done sustainably. The relationship between crop residue harvest, soil erosion, crop yield and carbon balance was modeled with the Erosion Productivity Impact Calculator/ Environment Policy Integrated Climate (EPIC) using a factorial design. Four crop rotations (winter wheat [Triticum aestivum (L.)] – sunflower [Helianthus annuus]; spring wheat [Triticum aestivum (L.)] – canola [Brassica napus]; corn [Zea mays L.] – soybean [Glycine max (L.) Merr.]; and cotton [Gossypium hirsutum] – peanut [Arachis hypogaea]) were simulated at four US locations each, under different topographies (0-10% slope), and management practices [crop residue removal rates (0-75%), conservation practices (no till, contour cropping, strip cropping, terracing)].

  18. Ocean sequestration of crop residue carbon: recycling fossil fuel carbon back to deep sediments.

    Science.gov (United States)

    Strand, Stuart E; Benford, Gregory

    2009-02-15

    For significant impact any method to remove CO2 from the atmosphere must process large amounts of carbon efficiently, be repeatable, sequester carbon for thousands of years, be practical, economical and be implemented soon. The only method that meets these criteria is removal of crop residues and burial in the deep ocean. We show here that this method is 92% efficient in sequestration of crop residue carbon while cellulosic ethanol production is only 32% and soil sequestration is about 14% efficient. Deep ocean sequestration can potentially capture 15% of the current global CO2 annual increase, returning that carbon backto deep sediments, confining the carbon for millennia, while using existing capital infrastructure and technology. Because of these clear advantages, we recommend enhanced research into permanent sequestration of crop residues in the deep ocean.

  19. Determine metrics and set targets for soil quality on agriculture residue and energy crop pathways

    Energy Technology Data Exchange (ETDEWEB)

    Ian Bonner; David Muth

    2013-09-01

    There are three objectives for this project: 1) support OBP in meeting MYPP stated performance goals for the Sustainability Platform, 2) develop integrated feedstock production system designs that increase total productivity of the land, decrease delivered feedstock cost to the conversion facilities, and increase environmental performance of the production system, and 3) deliver to the bioenergy community robust datasets and flexible analysis tools for establishing sustainable and viable use of agricultural residues and dedicated energy crops. The key project outcome to date has been the development and deployment of a sustainable agricultural residue removal decision support framework. The modeling framework has been used to produce a revised national assessment of sustainable residue removal potential. The national assessment datasets are being used to update national resource assessment supply curves using POLYSIS. The residue removal modeling framework has also been enhanced to support high fidelity sub-field scale sustainable removal analyses. The framework has been deployed through a web application and a mobile application. The mobile application is being used extensively in the field with industry, research, and USDA NRCS partners to support and validate sustainable residue removal decisions. The results detailed in this report have set targets for increasing soil sustainability by focusing on primary soil quality indicators (total organic carbon and erosion) in two agricultural residue management pathways and a dedicated energy crop pathway. The two residue pathway targets were set to, 1) increase residue removal by 50% while maintaining soil quality, and 2) increase soil quality by 5% as measured by Soil Management Assessment Framework indicators. The energy crop pathway was set to increase soil quality by 10% using these same indicators. To demonstrate the feasibility and impact of each of these targets, seven case studies spanning the US are presented

  20. How do soil quality indicators (SOC and nutrients) change with long-term different crop residue management?

    Science.gov (United States)

    Spiegel, Heide; Lehtinen, Taru; Dersch, Georg; Baumgarten, Andreas

    2016-04-01

    Leaving the crop residues (cereal grain straw, maize stover, sugar beet leaves) on the field may enhance SOC and soil nutrient contents (e.g. P, K, Mg). In contrast, harvesting crop residues for livestock bedding or energy production are often connected with a loss of soil fertility (Lehtinen et al., 2014). We have evaluated the effects of different management of crop residues on selected soil parameters of the upper soil (0-25 cm) in two long-term field experiments in Austria focused on P-dynamics (Marchfeld, since 1982 and Alpenvorland, since 1986). In four P-fertilisation stages (0, 75, 150, 300 kg P2O5 ha-1y-1) all crop residues were incorporated in one treatment and all removed in the other one, respectively. The results show that the effects are different at the two investigated sites. At the site Marchfeld, a medium textured soil, on average SOC was significantly higher with the incorporation of crop residues (21.6 g kg-1) compared to the removal (19.9 g kg-1) after 32 years. In the long run, SOC levels could be maintained, if crop residues remained at the field, whereas the constant removal of crop residues resulted in a SOC decline. At the site Alpenvorland, SOC was only slightly higher with the incorporation of the crop residues after 28 years. In this case, in the long run, even with this management practice and, moreover, with the residue removal, SOC tended to decrease generally. At the Marchfeld, crop residue incorporation resulted in a significant increase of "plant available" phosphorus (P-CAL) only with very high P fertilization. However, "plant available" Mg (according to Schachtschabel) and potassium (K-CAL) were significantly higher in all P fertilisation stages compared to the residue removal treatments. At the site Alpenvorland, the soils are rich in silt and clay and with long-term incorporation of crop residues a significant increase only of „plant available" K of about 50% occurred. This indicates the necessity of taking into account the

  1. Impact of diverse soil microbial communities on crop residues decomposition

    Science.gov (United States)

    Mrad, Fida; Bennegadi-Laurent, Nadia; Ailhas, Jérôme; Leblanc, Nathalie; Trinsoutrot-Gattin, Isabelle; Laval, Karine; Gattin, Richard

    2017-04-01

    Soils provide many basic ecosystem services for our society and most of these services are carried out by the soil communities, thus influencing soils quality. Soil organic matter (SOM) can be considered as one of the most important soil quality indices for it plays a determinant role in many physical, chemical and biological processes, such as soil structure and erosion resistance, cation exchange capacity, nutrient cycling and biological activity (Andrews et al., 2004). Since a long time, exogenous organic inputs are largely used for improving agricultural soils, affecting highly soil fertility and productivity. The use of organic amendments such as crop residues influences the soil microbial populations' diversity and abundance. In the meantime, soil microbial communities play a major role in the organic matter degradation, and the effect of different microbial communities on the decomposition of crop residues is not well documented. In this context, studying the impact of crop residues on soil microbial ecology and the processes controlling the fate of plant residues in different management practices is essential for understanding the long-term environmental and agronomic effects on soil and organic matters. Our purpose in the present work was to investigate the decomposition by two contrasting microbial communities of three crop residues, and compare the effect of different residues amendments on the abundance and function of each soil microbial communities. Among the main crops which produce large amounts of residues, we focused on three different plants: wheat (Triticum aestivum L.), rape (Brassica napus) and sunflower (Helianthus annuus). The residues degradation in two soils of different management practices and the microbial activity were evaluated by: microbial abundance (microbial carbon, culturable bacteria, total DNA, qPCR), in combination with functional indicators (enzymatic assays and Biolog substrate utilization), kinetics of C and N

  2. Crop residues reuse to improve agricultural soil quality

    OpenAIRE

    Cornejo, Jennifer Moreno; Cano, Angel Faz

    2008-01-01

    Since the 70´s in The Autonomous Community of the Region of Murcia, the irrigated agricultural area has increased, especially in the agrarian district “Comarca del Campo de Cartagena”, (South East of Spain). As a consequence, the amount of crop residues generated has gone up too. At the present, harvest residues constitute a very serious environmental problem because, in most cases, these residues are dehydrated on the land and burned later on with subsequent negative consequences...

  3. Cropping sequence and nitrogen fertilization impact on surface residue, soil carbon sequestration, and crop yields

    Science.gov (United States)

    Information is needed on the effect of management practices on soil C storage for obtaining C credit. The effects of tillage, cropping sequence, and N fertilization were evaluated on dryland crop and surface residue C and soil organic C (SOC) at the 0-120 cm depth in a Williams loam from 2006 to 201...

  4. Biogas production from energy crops and agriculture residues

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.

    2010-12-15

    In this thesis, the feasibility of utilizing energy crops (willow and miscanthus) and agriculture residues (wheat straw and corn stalker) in an anaerobic digestion process for biogas production was evaluated. Potential energy crops and agriculture residues were screened according to their suitability for biogas production. Moreover, pretreatment of these biomasses by using wet explosion method was studied and the effect of the wet explosion process was evaluated based on the increase of (a) sugar release and (b) methane potential when comparing the pretreated biomass and raw biomass. Ensiling of perennial crops was tested as a storage method and pretreatment method for enhancement of the biodegradability of the crops. The efficiency of the silage process was evaluated based on (a) the amount of biomass loss during storage and (b) the effect of the silage on methane potential. Co-digestion of raw and wet explosion pretreated energy crops and agriculture residues with swine manure at various volatile solids (VS) ratio between crop and manure was carried out by batch tests and continuous experiments. The efficiency of the co-digestion experiment was evaluated based on (a) the methane potential in term of ml CH4 produced per g of VS-added and (b) the amount of methane produced per m3 of reactor volume. (Author)

  5. Biogas Production from Energy Crops and Agriculture Residues

    DEFF Research Database (Denmark)

    Wang, Guangtao

    In this thesis, the feasibility of utilizing energy crops (willow and miscanthus) and agriculture residues (wheat straw and corn stalker) in an anaerobic digestion process for biogas production was evaluated. Potential energy crops and agriculture residues were screened according...... to their suitability for biogas production. Moreover, pretreatment of these biomasses by using wet explosion method was studied and the effect of the wet explosion process was evaluated based on the increase of (a) sugar release and (b) methane potential when comparing the pretreated biomass and raw biomass. Ensiling...

  6. Crop residue decomposition in Minnesota biochar amended plots

    Science.gov (United States)

    Weyers, S. L.; Spokas, K. A.

    2014-02-01

    Impacts of biochar application at laboratory scales are routinely studied, but impacts of biochar application on decomposition of crop residues at field scales have not been widely addressed. The priming or hindrance of crop residue decomposition could have a cascading impact on soil processes, particularly those influencing nutrient availability. Our objectives were to evaluate biochar effects on field decomposition of crop residue, using plots that were amended with biochars made from different feedstocks and pyrolysis platforms prior to the start of this study. Litterbags containing wheat straw material were buried below the soil surface in a continuous-corn cropped field in plots that had received one of seven different biochar amendments or a non-charred wood pellet amendment 2.5 yr prior to start of this study. Litterbags were collected over the course of 14 weeks. Microbial biomass was assessed in treatment plots the previous fall. Though first-order decomposition rate constants were positively correlated to microbial biomass, neither parameter was statistically affected by biochar or wood-pellet treatments. The findings indicated only a residual of potentially positive and negative initial impacts of biochars on residue decomposition, which fit in line with established feedstock and pyrolysis influences. Though no significant impacts were observed with field-weathered biochars, effective soil management may yet have to account for repeat applications of biochar.

  7. Crop residue decomposition, residual soil organic matter and nitrogen mineralization in arable soils with contrasting textures

    NARCIS (Netherlands)

    Matus, F.J.

    1994-01-01

    To evaluate the significance of cropping, soil texture and soil structure for the decomposition of 14C- and 15N-labelled crop residues, a study was conducted in a sand and a

  8. Review of Alternative Management Options of Vegetable Crop Residues to Reduce Nitrate Leaching in Intensive Vegetable Rotations

    Directory of Open Access Journals (Sweden)

    Laura Agneessens

    2014-12-01

    Full Text Available Vegetable crop residues take a particular position relative to arable crops due to often large amounts of biomass with a N content up to 200 kg N ha−1 left behind on the field. An important amount of vegetable crops are harvested during late autumn and despite decreasing soil temperatures during autumn, high rates of N mineralization and nitrification still occur. Vegetable crop residues may lead to considerable N losses through leaching during winter and pose a threat to meeting water quality objectives. However, at the same time vegetable crop residues are a vital link in closing the nutrient and organic matter cycle of soils. Appropriate and sustainable management is needed to harness the full potential of vegetable crop residues. Two fundamentally different crop residue management strategies to reduce N losses during winter in intensive vegetable rotations are reviewed, namely (i on-field management options and modifications to crop rotations and (ii removal of crop residues, followed by a useful and profitable application.

  9. Crop residue management in arable cropping systems under a temperate climate. Part 2: Soil physical properties and crop production. A review

    Directory of Open Access Journals (Sweden)

    Hiel, MP.

    2016-01-01

    Full Text Available Introduction. Residues of previous crops provide a valuable amount of organic matter that can be used either to restore soil fertility or for external use. A better understanding of the impact of crop residue management on the soil-water-plant system is needed in order to manage agricultural land sustainably. This review focuses on soil physical aspects related to crop residue management, and specifically on the link between soil structure and hydraulic properties and its impact on crop production. Literature. Conservation practices, including crop residue retention and non-conventional tillage, can enhance soil health by improving aggregate stability. In this case, water infiltration is facilitated, resulting in an increase in plant water availability. Conservation practices, however, do not systematically lead to higher water availability for the plant. The influence of crop residue management on crop production is still unclear; in some cases, crop production is enhanced by residue retention, but in others crop residues can reduce crop yield. Conclusions. In this review we discuss the diverse and contrasting effects of crop residue management on soil physical properties and crop production under a temperate climate. The review highlights the importance of environmental factors such as soil type and local climatic conditions, highlighting the need to perform field studies on crop residue management and relate them to specific pedo-climatic contexts.

  10. Partitioning Residue-derived and Residue-induced Emissions of N2O Using 15N-labelled Crop Residues

    Science.gov (United States)

    Farrell, R. E.; Carverhill, J.; Lemke, R.; Knight, J. D.

    2014-12-01

    Estimates of N2O emissions in Canada indicate that 17% of all agriculture-based emissions are associated with the decomposition of crop residues. However, research specific to the western Canadian prairies (including Saskatchewan) has shown that the N2O emission factor for N sources in this region typically ranges between 0.2 and 0.6%, which is well below the current IPCC default emission factor of 1.0%. Thus, it stands to reason that emissions from crop residues should also be lower than those calculated using the current IPCC emission factor. Current data indicates that residue decomposition, N mineralization and N2O production are affected by a number of factors such as C:N ratio and chemical composition of the residue, soil type, and soil water content; thus, a bench-scale incubation study was conducted to examine the effects of soil type and water content on N2O emissions associated with the decomposition of different crop residues. The study was carried out using soils from the Black, Dark Brown, Brown, and Gray soil zones and was conducted at both 50% and 70% water-filled pore space (WFPS); the soils were amended with 15N-labeled residues of wheat, pea, canola, and flax, or with an equivalent amount of 15N-labeled urea; 15N2O production was monitored using a Picarro G5101-i isotopic N2O analyzer. Crop residue additions to the soils resulted in both direct and indirect emissions of N2O, with residue derived emissions (RDE; measured as 15N2O) generally exceeding residue-induced emissions (RIE) at 50% WFPS—with RDEs ranging from 42% to 88% (mean = 58%) of the total N2O. Conversely, at 70% WFPS, RDEs were generally lower than RIEs—ranging from 21% to 83% (mean = 48%). Whereas both water content and soil type had an impact on N2O production, there was a clear and consistent trend in the emission factors for the residues; i.e., emissions were always greatest for the canola residue and lowest for the wheat residue and urea fertilizer; and intermediate for pea

  11. Decomposition of sugar cane crop residues under different nitrogen rates

    Directory of Open Access Journals (Sweden)

    Douglas Costa Potrich

    2014-09-01

    Full Text Available The deposition of organic residues through mechanical harvesting of cane sugar is a growing practice in sugarcane production system. The maintenance of these residues on the soil surface depends mainly on environmental conditions. Nitrogen fertilization on dry residues tend to retard decomposition of these, providing benefits such as increased SOM. Thus, the object of this research was to evaluate the effect of different doses of nitrogen on sugar cane crop residues, as its decomposition and contribution to carbon sequestration in soil. The experiment was conducted in Dourados-MS and consisted of a randomized complete block design. Dried residues were placed in litter bags and the treatments were arranged in a split plot, being the four nitrogen rates (0, 50, 100 and 150 kg ha-1 N the plots, and the seven sampling times (0, 30, 60, 90, 120, 150 and 180 the spit plots. Decomposition rates of residues, total organic carbon and labile carbon on soil were analysed. The application of increasing N doses resulted in an increase in their decomposition rates. Despite this, note also the mineral N application as a strategy to get higher levels of labile carbon in soil.

  12. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  13. Amendment of Acid Soils with Crop Residues and Biochars

    Institute of Scientific and Technical Information of China (English)

    YUAN Jin-Hua; XU Ren-Kou; WANG Ning; LI Jiu-Yu

    2011-01-01

    The liming potential of some crop residues and their biochars on an acid Ultisol was investigated using incubation experiments. Rice hulls showed greater liming potential than rice hull biochar, while soybean and pea straws had less liming potential than their biochars. Due to their higher alkalinity, biochars from legume materials increased soil pH much compared to biochars from non-legume materials. The alkalinity of biochars was a key factor affecting their liming potential,and the greater alkalinity of biochars led to greater reductions in soil acidity. The incorporation of biochars decreased soil exchangeable acidity and increased soil exchangeable base cations and base saturation, thus improving soil fertility.

  14. Distribution, timing of attack, and oviposition of the banana weevil, Cosmopolites sordidus, on banana crop residues in Uganda

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.

    2005-01-01

    Crop sanitation (removal and chopping of residue corms and pseudostems following plant harvest) has been recommended as a 'best bet' means of reducing banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), populations. However, it has been unclear when such practices should be ca

  15. A quantitative assessment of crop residue feedstocks for biofuel in North and Northeast China

    NARCIS (Netherlands)

    Yang, L.; Wang, X.Y.; Han, L.P.; Spiertz, J.H.J.; Liao, S.H.; Wei, M.G.; Xie, G.H.

    2015-01-01

    Crop residue resources may affect soil quality, global carbon balance, and stability of crop production, but also contribute to future energy security. This study was performed to evaluate the spatial and temporal variation in residue quantities of field crops in five provinces of North China (NC) a

  16. Characterization of Proteins in Filtrate from Biodegradation of Crop Residue

    Science.gov (United States)

    Horton, Wileatha; Trotman, A. A.

    1997-01-01

    Biodegradation of plant biomass is a feasible path for transformation of crop residue and recycling of nutrients for crop growth. The need to model the effects of factors associated with recycling of plant biomass resulting from hydroponic sweet potato production has led to investigation of natural soil isolates with the capacity for starch hydrolysis. This study sought to use nondenaturing gel electrophoresis to characterize the proteins present in filtered effluent from bioreactors seeded with starch hydrolyzing bacterial culture used in the biodegradation of senesced sweet potato biomass. The study determined the relative molecular weight of proteins in sampled effluent and the protein banding pattern was characterized. The protein profiles of effluent were similar for samples taken from independent runs under similar conditions of starch hydrolysis. The method can be used as a quality control tool for confirmation of starch hydrolysis of crop biomass. In addition, this method will allow monitoring for presence of contaminants within the system-protein profiles indicative of new enzymes in the bioreactors.

  17. Soil carbon and nitrogen fractions and crop yields affected by residue placement and crop types.

    Science.gov (United States)

    Wang, Jun; Sainju, Upendra M

    2014-01-01

    Soil labile C and N fractions can change rapidly in response to management practices compared to non-labile fractions. High variability in soil properties in the field, however, results in nonresponse to management practices on these parameters. We evaluated the effects of residue placement (surface application [or simulated no-tillage] and incorporation into the soil [or simulated conventional tillage]) and crop types (spring wheat [Triticum aestivum L.], pea [Pisum sativum L.], and fallow) on crop yields and soil C and N fractions at the 0-20 cm depth within a crop growing season in the greenhouse and the field. Soil C and N fractions were soil organic C (SOC), total N (STN), particulate organic C and N (POC and PON), microbial biomass C and N (MBC and MBN), potential C and N mineralization (PCM and PNM), NH4-N, and NO3-N concentrations. Yields of both wheat and pea varied with residue placement in the greenhouse as well as in the field. In the greenhouse, SOC, PCM, STN, MBN, and NH4-N concentrations were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow. In the field, MBN and NH4-N concentrations were greater in no-tillage than conventional tillage, but the trend reversed for NO3-N. The PNM was greater under pea or fallow than wheat in the greenhouse and the field. Average SOC, POC, MBC, PON, PNM, MBN, and NO3-N concentrations across treatments were higher, but STN, PCM and NH4-N concentrations were lower in the greenhouse than the field. The coefficient of variation for soil parameters ranged from 2.6 to 15.9% in the greenhouse and 8.0 to 36.7% in the field. Although crop yields varied, most soil C and N fractions were greater in surface placement than incorporation of residue and greater under wheat than pea or fallow in the greenhouse than the field within a crop growing season. Short-term management effect on soil C and N fractions were readily obtained with reduced variability under controlled soil and

  18. Lignin biochemistry and soil N determine crop residue decomposition and soil priming

    Science.gov (United States)

    Cropping history can affect soil properties, including available N, but little is known about the interactive effects of residue biochemistry, temperature and cropping history on residue decomposition. A laboratory incubation examined the role of residue biochemistry and temperature on the decomposi...

  19. Effect of crop residue incorporation on soil organic carbon (SOC) and greenhouse gas (GHG) emissions in European agricultural soils

    Science.gov (United States)

    Lehtinen, Taru; Schlatter, Norman; Baumgarten, Andreas; Bechini, Luca; Krüger, Janine; Grignani, Carlo; Zavattaro, Laura; Costamagna, Chiara; Spiegel, Heide

    2014-05-01

    Soil organic matter (SOM) improves soil physical (e.g. increased aggregate stability), chemical (e.g. cation exchange capacity) and biological (e.g. biodiversity, earthworms) properties. The sequestration of soil organic carbon (SOC) may mitigate climate change. However, as much as 25-75% of the initial SOC in world agricultural soils may have been lost due to intensive agriculture (Lal, 2013). The European Commission has described the decline of organic matter (OM) as one of the major threats to soils (COM(2006) 231). Incorporation of crop residues may be a sustainable and cost-efficient management practice to maintain the SOC levels and to increase soil fertility in European agricultural soils. Especially Mediterranean soils that have low initial SOC concentrations, and areas where stockless croplands predominate may be suitable for crop residue incorporation. In this study, we aim to quantify the effects of crop residue incorporation on SOC and GHG emissions (CO2 and N2O) in different environmental zones (ENZs, Metzger et al., 2005) in Europe. Response ratios for SOC and GHG emissions were calculated from pairwise comparisons between crop residue incorporation and removal. Specifically, we investigated whether ENZs, clay content and experiment duration influence the response ratios. In addition, we studied how response ratios of SOM and crop yields were correlated. A total of 718 response ratios (RR) were derived from a total of 39 publications, representing 50 experiments (46 field and 4 laboratory) and 15 countries. The SOC concentrations and stocks increased by approximately 10% following crop residue incorporation. In contrast, CO2 emissions were approximately six times and N2O emissions 12 times higher following crop residue incorporation. The effect of ENZ on the response ratios was not significant. For SOC concentration, the >35% clay content had significantly approximately 8% higher response ratios compared to 18-35% clay content. As the duration of the

  20. Cost Methodology for Biomass Feedstocks: Herbaceous Crops and Agricultural Residues

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow Jr, Anthony F [ORNL; Webb, Erin [ORNL; Sokhansanj, Shahabaddine [ORNL

    2009-12-01

    This report describes a set of procedures and assumptions used to estimate production and logistics costs of bioenergy feedstocks from herbaceous crops and agricultural residues. The engineering-economic analysis discussed here is based on methodologies developed by the American Society of Agricultural and Biological Engineers (ASABE) and the American Agricultural Economics Association (AAEA). An engineering-economic analysis approach was chosen due to lack of historical cost data for bioenergy feedstocks. Instead, costs are calculated using assumptions for equipment performance, input prices, and yield data derived from equipment manufacturers, research literature, and/or standards. Cost estimates account for fixed and variable costs. Several examples of this costing methodology used to estimate feedstock logistics costs are included at the end of this report.

  1. Stover removal and cover crops effects on corn production and water use under full and limited irrigation

    Science.gov (United States)

    Corn (Zea mays L.) residue removal in irrigated cropping systems for livestock forage or cellulosic ethanol is of great interest in south-central Nebraska. Irrigation water restrictions in the region have also resulted in adoption of limited-irrigation strategies. Little is known regarding the inter...

  2. Sustainability of soil fertility and the use of lignocellulosic crop harvest residues for the production of biofuels: a literature review.

    Science.gov (United States)

    Reijnders, L

    2013-01-01

    Use of lignocellulosic crop harvest residues for liquid or gaseous biofuel production may impact soil quality, long-term soil fertility and the major determinants of the latter, stocks of soil organic carbon and nutrients. When soil organic carbon stocks of mineral cropland soils are to be maintained, there is scope for the removal of lignocellulosic harvest residues in several systems with much reduced tillage or no tillage. The scope for such removal might be increased when suitably treated residues from the conversion of harvest residues into biofuel are returned to cropland soils. For mineral cropland soils under conventional tillage, the scope for the production of liquid biofuels from harvest residues is likely to be less than in the case of no-till systems. When fertility of cropland soils is to be sustainable, nutrients present in suitably treated biofuel production residues have to be returned to these soils. Apparently, the actual return of carbon and nutrients present in residues of biofuel production from crop harvest residues to arable soils currently predominantly concerns the application of digestates of anaerobic digestion. The effects thereof on soil fertility and quality need further clarification. Further clarification about the effects on soil fertility and quality of chars and of co-products of lignocellulosic ethanol production is also needed.

  3. Effect of pre-treatments on methane production potential of energy crops and crop residues

    Energy Technology Data Exchange (ETDEWEB)

    Lehtomaki, A.; Ronkainen; Rintala, J.A. [Jyvaskla Univ. (Finland). Dept. of Biological and Environmental Sciences; Viinikainen, T.A. [Jyvaskla Univ. (Finland). Dept. of Chemistry

    2004-07-01

    Energy crops, that is, crops grown specifically for energy purposes are an alternative to food production in areas with sufficient agricultural land. Crop residues are also a potential source of energy. The anaerobic digestion of solid materials is limited by hydrolysis of complex polymeric substances such as lignocellulose. The methane producing potential of ligno cellulosic material is to pretreat the substrate in order to break up the polymer chains to more easily accessible soluble compounds. In this study, three different substrates were used: sugar beet tops, grass hay, and straw of oats. Biological pretreatments were the following: enzyme treatment, composting, white-rot fungi treatment. Also, pretreatment in water was tried. Chemical pretreatments included peracetic acid treatment, and treatment with two different alkalis. Alkaline pretreatments of hay and sugar beet tops have the potential to improve the methane yield. For instance, the yield of grass hay was increased 15 per cent by one particular alkaline treatment. Straw did not respond to any of the treatments tried. 18 refs., 1 tab., 2 figs.

  4. The Impacts of Agricultural Machinery Purchase Subsidies on Mechanized Crop Residue Recycling

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Crop residue recycling can improve the quality of the cropland,and it has multiple economic and ecological benefits.However,such practice is with low adoption due to different constraints.In this paper,we use the survey data from Baoding,Hebei province,and use the probit model to explore how the agricultural machinery purchase subsidies affect the mechanized crop residue recycling.The results showed that several factors that affect farmers in adopting the practice of mechanized crop residue crop recycling.Among these factors,the cost of adopting such practice is significant.The agricultural machinery purchase subsidies can effectively reduce the cost of such practice,as well as promote mechanized crop residue recycling.The paper also proposed several actions in the future.They include increasing the subsidies on agricultural machinery purchase and increasing farmers’ awareness on crop residue recycling.

  5. Residual Influence of Early Season Crop Fertilization and Cropping System on Growth and Yield of Cassava

    Directory of Open Access Journals (Sweden)

    E. A. Makinde

    2008-01-01

    Full Text Available Problem statement: In assessing fertilizer effects to sustain an intensive cropping system, the residual effects of fertilizer applied to preceding maize on the growth and yield of cassava and the effects of intercropping with soybean were studied in field experiments at Ibadan, Nigeria. Approach: Maize, established in April was fertilized using either organic manure or inorganic fertilizer or a mixture of organic manure and inorganic fertilizers. Organic manure was an equal mixture of domestic waste collected from a composted refuse dumping site applied at l0 t ha-1. Inorganic fertilizer was 150kg N supplied as urea and 50 kg P ha-1 as Single Super phosphate fertilizer. The mixture of organic and inorganic fertilizer treatment was 5 tonnes organic manure and 75kg N+25 kg P ha-1. Cassava was established in June and soybean planted in July, after harvesting maize. Results: Organic fertilizer treatment gave the tallest plants of 53 cm. Plants from sole inorganic fertilizer and from a mixture of organic and inorganic fertilizers had comparable heights but were significantly lower than plants from sole organic fertilizer application. Organic fertilizer application gave the highest seed yield of 481 kg ha-1 that was significantly higher than 380 kg ha-1 observed from a mixture of organic and inorganic fertilizers. Stover yield followed the same trend as seed yield. Cassava plant height was increased with fertilization but was reduced with intercropping. Sole organic fertilization had the tallest plants. Plant leaf area was neither significantly affected by fertilizer type nor cropping system. Fresh root yield was significantly reduced by 16% with soybean intercropping. Sole organic fertilizer application gave the highest yields of 22 tons ha-1 in sole crop and 18 tons ha-1 in intercrop with soybean. Conclusion: Cultivating an early season maize crop, followed by a cassava-soybean intercrop is more

  6. Effects of Maize Residue Removal and Tillage on Soil Erosion, Carbon, and Macronutrient Dynamics

    Science.gov (United States)

    Beniston, J.; Shipitalo, M.; Lal, R.; Dayton, E. A.; Hopkins, D.; Jones, F. S.; Joynes, A.; Dungait, J.

    2013-12-01

    Erosion by water is a principal process of soil degradation in agricultural lands. Soil erosion influences the storage and fluxes of C and key macronutrients N and P in soil surface layers. No till (NT) crop management significantly reduces erosion on susceptible landscapes. The selective removal of crop residues for bio-energy production from no-till systems has been suggested as a secondary crop, but the effect of this practice on the conservation benefits of NT has not been quantified. Therefore, this study was initiated in spring 2012 to examine the effects of soil management practices on erosion and associated macronutrient fluxes on erodible soils subjected to a high intensity simulated rain storm at the North Appalachian Experimental Watershed (NAEW) in Coshocton, OH, U.S.A. The soil management practices evaluated included: long term no-till with 100% crop residue (NT100) , no-till with 50% crop reside (NT50), NT with complete crop residue removal (NT0), long term conventional tillage (CT), and long term no-tillage plots that were cultivated (TNT) with a rototiller before the rainfall application. A field rainfall simulator was utilized to apply rainfall at an intensity of 7 cm hr-1 to a 4 m2 area of each plot for 30 minutes. Total runoff from the NT0 plots (22.1 mm) was almost double compared with the NT 50% (13.3 mm), CT (12.8 mm) and TNT (12.8 mm) plots and was more than 5 times greater than the NT100 plots (4.4mm). CT and NT0 plots produced 40 (2.7 Mg ha-1) and 20 times (1.4 Mg ha-1) more soil loss, respectively, than NT100 plots (0.07 Mg ha-1). Tillage of the no-till (TNT) soil produced the largest sediment-bound fluxes of C and N, while sediment-bound P fluxes were largest in the CT soils. Natural abundance δ13C and δ15N values were distinct between eroded sediments and the source topsoils and suggested enhanced loss of older (>28 yrs) C residues in CT plots. All observations suggest NT management provides greater resilience to soils than CT during

  7. Measurement of the fluorescence of crop residues: A tool for controlling soil erosion

    Science.gov (United States)

    Daughtry, C. S. T.; Mcmurtrey, J. E., III; Chappelle, E. W.; Hunter, W. J.

    1994-01-01

    Management of crop residues, the portion of a crop left in the field after harvest, is an important conservation practice for minimizing soil erosion and for improving water quality. Quantification of crop residue cover is required to evaluate the effectiveness of conservation tillage practices. Methods are needed to quantify residue cover that are rapid, accurate, and objective. The fluorescence of crop residue was found to be a broadband phenomenon with emission maxima at 420 to 495 nm for excitations of 350 to 420 nm. Soils had low intensity broadband emissions over the 400 to 690 nm region for excitations of 300 to 600 nm. The range of relative fluorescence intensities for the crop residues was much greater than the fluorescence observed of the soils. As the crop residues decompose their blue fluorescence values approach the fluorescence of the soil. Fluorescence techniques are concluded to be less ambiguous and better suited for discriminating crop residues and soils than reflectance methods. If properly implemented, fluorescence techniques can be used to quantify, not only crop residue cover, but also photosynthetic efficiency in the field.

  8. Analyzing key constraints to biogas production from crop residues and manure in the EU—A spatially explicit model

    Science.gov (United States)

    Persson, U. Martin

    2017-01-01

    This paper presents a spatially explicit method for making regional estimates of the potential for biogas production from crop residues and manure, accounting for key technical, biochemical, environmental and economic constraints. Methods for making such estimates are important as biofuels from agricultural residues are receiving increasing policy support from the EU and major biogas producers, such as Germany and Italy, in response to concerns over unintended negative environmental and social impacts of conventional biofuels. This analysis comprises a spatially explicit estimate of crop residue and manure production for the EU at 250 m resolution, and a biogas production model accounting for local constraints such as the sustainable removal of residues, transportation of substrates, and the substrates’ biochemical suitability for anaerobic digestion. In our base scenario, the EU biogas production potential from crop residues and manure is about 0.7 EJ/year, nearly double the current EU production of biogas from agricultural substrates, most of which does not come from residues or manure. An extensive sensitivity analysis of the model shows that the potential could easily be 50% higher or lower, depending on the stringency of economic, technical and biochemical constraints. We find that the potential is particularly sensitive to constraints on the substrate mixtures’ carbon-to-nitrogen ratio and dry matter concentration. Hence, the potential to produce biogas from crop residues and manure in the EU depends to large extent on the possibility to overcome the challenges associated with these substrates, either by complementing them with suitable co-substrates (e.g. household waste and energy crops), or through further development of biogas technology (e.g. pretreatment of substrates and recirculation of effluent). PMID:28141827

  9. Analyzing key constraints to biogas production from crop residues and manure in the EU-A spatially explicit model.

    Science.gov (United States)

    Einarsson, Rasmus; Persson, U Martin

    2017-01-01

    This paper presents a spatially explicit method for making regional estimates of the potential for biogas production from crop residues and manure, accounting for key technical, biochemical, environmental and economic constraints. Methods for making such estimates are important as biofuels from agricultural residues are receiving increasing policy support from the EU and major biogas producers, such as Germany and Italy, in response to concerns over unintended negative environmental and social impacts of conventional biofuels. This analysis comprises a spatially explicit estimate of crop residue and manure production for the EU at 250 m resolution, and a biogas production model accounting for local constraints such as the sustainable removal of residues, transportation of substrates, and the substrates' biochemical suitability for anaerobic digestion. In our base scenario, the EU biogas production potential from crop residues and manure is about 0.7 EJ/year, nearly double the current EU production of biogas from agricultural substrates, most of which does not come from residues or manure. An extensive sensitivity analysis of the model shows that the potential could easily be 50% higher or lower, depending on the stringency of economic, technical and biochemical constraints. We find that the potential is particularly sensitive to constraints on the substrate mixtures' carbon-to-nitrogen ratio and dry matter concentration. Hence, the potential to produce biogas from crop residues and manure in the EU depends to large extent on the possibility to overcome the challenges associated with these substrates, either by complementing them with suitable co-substrates (e.g. household waste and energy crops), or through further development of biogas technology (e.g. pretreatment of substrates and recirculation of effluent).

  10. [Quantification of crop residue burned areas based on burning indices using Landsat 8 image].

    Science.gov (United States)

    Ma, Jian-hang; Song, Kai-shar; Wen, Zhi-dan; Shao, Tian-tian; Li, Bo-nan; Qi, Cai

    2015-11-01

    Crop residue burning leads to atmospheric pollution and is an enormous waste of crop residue resource. Crop residue burning can be monitored timely in large regions as the fire points can be recognized through remotely sensed image via thermal infrared bands. However, the area, the detailed distribution pattern and especially the severity of the burning areas cannot be derived only by the thermal remote sensing approach. The burning index, which was calculated with two or more spectral bands at where the burned and unburned areas have distinct spectral characteristics, is widely used in the forest fire investigation. However its potential application for crop residue burning evaluation has not been explored. With two Landsat 8 images that cover a part of the Songnen Plain, three burning indices, i.e., the normalized burned ratio (NBR), the normalized burned ratio incorporating the thermal band (NBRT), and the burned area index (BAI), were used to classify the crop residue burned and unburned areas. The overall classification accuracies were 91.9%, 92.3%, and 87.8%, respectively. The correlation analysis between the indices and the crop residue coverage indicated that the NBR and NBRT were positively correlated with the crop residue coverage (R2 = 0.73 and 0.64, respectively) with linear regression models, while the BAI was exponentially correlated with the crop residue coverage (R2 = 0.68). The results indicated that the use of burning indices in crop residue burning monitoring could quantify crop residue burning severity and provide valuable data for evaluating atmospheric pollution.

  11. Positive feedback of crop residue incorporation on dissolved organic carbon contents under anaerobic conditions in temperate rice paddy soils

    Science.gov (United States)

    Said-Pullicino, Daniel; Sodano, Marcella; Bertora, Chiara; Lerda, Cristina; Sacco, Dario; Celi, Luisella

    2016-04-01

    Rice paddy soils are generally characterized by large concentrations and fluxes of DOC in comparison to other ecosystems. Our recent studies have shown that the combination of relatively high pore-water DOC concentrations under anoxic soil conditions (>10-20 mg C l-1) and important percolation fluxes of water during field flooding may contribute significant organic C inputs into the subsoil (18-51 g C m-2) over the cropping season. Crop residues incorporated into the soil after harvest represent the main input of organic C into paddy soils, returning about 200-300 g C m-2 y-1 in single-cropped rice paddies. The anaerobic decomposition of these residues may supply important amounts of DOC to soil pore waters. Moreover, the supply of electron donors with the input of residue-derived labile OM may further increase DOC contents by stimulating the microbially-catalyzed reductive dissolution of Fe and Mn oxyhydroxides under anoxic conditions, and release of DOC previously stabilized on the mineral matrix (i.e. positive feedback). This could have important implications on organic C inputs into the subsoil as well as substrate availability for methane production. We therefore hypothesized that crop residue management practices that influence the amount of labile organic matter present in the soil at the time of field flooding may strongly influence soil solution DOC concentrations as well as the positive feedback on the release of soil-derived DOC. We tested this hypothesis at field-scale by evaluating variations in the contents and quality of DOC above and beneath the plough pan over the cropping season as a function of crop residue management practices involving: tillage and crop residue incorporation in spring (SPR), tillage and crop residue incorporation in spring, dry seeding and 1 month delayed flooding (DRY), tillage and crop residue incorporation in autumn (AUT), and straw removal after harvest and tillage in spring (REM). Moreover, we linked changes in DOC

  12. Characterization of protein and carbohydrate mid-IR spectral features in crop residues

    Science.gov (United States)

    Xin, Hangshu; Zhang, Yonggen; Wang, Mingjun; Li, Zhongyu; Wang, Zhibo; Yu, Peiqiang

    2014-08-01

    To the best of our knowledge, a few studies have been conducted on inherent structure spectral traits related to biopolymers of crop residues. The objective of this study was to characterize protein and carbohydrate structure spectral features of three field crop residues (rice straw, wheat straw and millet straw) in comparison with two crop vines (peanut vine and pea vine) by using Fourier transform infrared spectroscopy (FTIR) technique with attenuated total reflectance (ATR). Also, multivariate analyses were performed on spectral data sets within the regions mainly related to protein and carbohydrate in this study. The results showed that spectral differences existed in mid-IR peak intensities that are mainly related to protein and carbohydrate among these crop residue samples. With regard to protein spectral profile, peanut vine showed the greatest mid-IR band intensities that are related to protein amide and protein secondary structures, followed by pea vine and the rest three field crop straws. The crop vines had 48-134% higher spectral band intensity than the grain straws in spectral features associated with protein. Similar trends were also found in the bands that are mainly related to structural carbohydrates (such as cellulosic compounds). However, the field crop residues had higher peak intensity in total carbohydrates region than the crop vines. Furthermore, spectral ratios varied among the residue samples, indicating that these five crop residues had different internal structural conformation. However, multivariate spectral analyses showed that structural similarities still exhibited among crop residues in the regions associated with protein biopolymers and carbohydrate. Further study is needed to find out whether there is any relationship between spectroscopic information and nutrition supply in various kinds of crop residue when fed to animals.

  13. Herbicide and cover crop residue integration in conservation tillage tomato

    Science.gov (United States)

    The increased adoption of conservation tillage in vegetable production requires more information on the role of various cover crops in weed control, tomato quality, and yield. Three conservation-tillage systems utilizing crimson clover, turnip, and cereal rye as winter cover crops were compared to a...

  14. Cumulative and residual effects of potato cropping system management strategies on crop and soil health parameters

    Science.gov (United States)

    Soil and crop management practices can greatly affect parameters related to soil health, as well as crop productivity and disease development, and may provide options for more sustainable production. Different 3-yr potato cropping systems focused on specific management goals of soil conservation (SC...

  15. Spectral Indices to Improve Crop Residue Cover Estimation under Varying Moisture Conditions

    Directory of Open Access Journals (Sweden)

    Miguel Quemada

    2016-08-01

    Full Text Available Crop residues on the soil surface protect the soil against erosion, increase water infiltration and reduce agrochemicals in runoff water. Crop residues and soils are spectrally different in the absorption features associated with cellulose and lignin. Our objectives were to: (1 assess the impact of water on the spectral indices for estimating crop residue cover (fR; (2 evaluate spectral water indices for estimating the relative water content (RWC of crop residues and soils; and (3 propose methods that mitigate the uncertainty caused by variable moisture conditions on estimates of fR. Reflectance spectra of diverse crops and soils were acquired in the laboratory over the 400–2400-nm wavelength region. Using the laboratory data, a linear mixture model simulated the reflectance of scenes with various fR and levels of RWC. Additional reflectance spectra were acquired over agricultural fields with a wide range of crop residue covers and scene moisture conditions. Spectral indices for estimating crop residue cover that were evaluated in this study included the Normalized Difference Tillage Index (NDTI, the Shortwave Infrared Normalized Difference Residue Index (SINDRI and the Cellulose Absorption Index (CAI. Multivariate linear models that used pairs of spectral indices—one for RWC and one for fR—significantly improved estimates of fR using CAI and SINDRI. For NDTI to reliably assess fR, scene RWC should be relatively dry (RWC < 0.25. These techniques provide the tools needed to monitor the spatial and temporal changes in crop residue cover and help determine where additional conservation practices may be required.

  16. Crop residue is key for sustaining maximum food production and for conservation of our biosphere

    Science.gov (United States)

    Crop residue is key in our efforts to move towards agricultural sustainability. This paper provides a quick overview of some selected references and looks at some of the newest advances related to cover crops. Several authors have described in detail the benefits derived from improving soil quality ...

  17. Developing an Integrated Model Framework for the Assessment of Sustainable Agricultural Residue Removal Limits for Bioenergy Systems

    Energy Technology Data Exchange (ETDEWEB)

    David Muth, Jr.; Jared Abodeely; Richard Nelson; Douglas McCorkle; Joshua Koch; Kenneth Bryden

    2011-08-01

    Agricultural residues have significant potential as a feedstock for bioenergy production, but removing these residues can have negative impacts on soil health. Models and datasets that can support decisions about sustainable agricultural residue removal are available; however, no tools currently exist capable of simultaneously addressing all environmental factors that can limit availability of residue. The VE-Suite model integration framework has been used to couple a set of environmental process models to support agricultural residue removal decisions. The RUSLE2, WEPS, and Soil Conditioning Index models have been integrated. A disparate set of databases providing the soils, climate, and management practice data required to run these models have also been integrated. The integrated system has been demonstrated for two example cases. First, an assessment using high spatial fidelity crop yield data has been run for a single farm. This analysis shows the significant variance in sustainably accessible residue across a single farm and crop year. A second example is an aggregate assessment of agricultural residues available in the state of Iowa. This implementation of the integrated systems model demonstrates the capability to run a vast range of scenarios required to represent a large geographic region.

  18. Tillage as a tool to manage crop residue: impact on sugar beet production.

    Science.gov (United States)

    Hiel, Marie-Pierre; Chélin, Marie; Degrune, Florine; Parvin, Nargish; Bodson, Bernard

    2015-04-01

    Crop residues and plant cover represent a pool of organic matter that can be used either to restore organic matter in soils, and therefore maintain soil fertility, or that can be valorized outside of the field (e.g. energy production). However, it is crucial that the exportation of residues is not done to the detriment of the system sustainability. Three long term experiments have been settled in the loamy region in Belgium. All of them are designed to study the effect of residues management by several tillage systems (conventional plowing versus reduced tillage) on the whole soil-water-plant system. SOLRESIDUS is a field experiment where we study the impact of crop residue management while in SOLCOUVERT and SOLCOUVERT-BIS, we study the impact of cover crop management. SOLRESIDUS was started in 2008. In this field, four contrasted crop residues managements are tested in order to contrast as much as possible the responses from the soil-water plant system. Two practices characterize the four modalities: soil tillage (ploughing at 25 cm depth or reduce tillage at 10 cm max) and residue management (exportation or restitution). SOLCOUVERT and SOLCOUVERT-BIS were started in 2012 and 2013 respectively. In those fields cover crop management is also diverse: destruction of the cover crop by winter ploughing, spring ploughing, strip tillage (with a chemical destruction if needed) or shallow tillage (with a decompaction before cover crop sowing). Although although the overall project aims at studying the impact of management on the whole soil-water-plant system, here we will only present the results concerning crop production (sugar beet) in SOLCOUVERT experiments. The presented data will include germination rate, crop development (biomass quantification and BBCH stages) weeds population, disease occurrence, pest occurrences, nitrogen uptake by plants, quality and quantity of harvested products.

  19. The Effect of Conservation Tillage and Cover Crop Residue on Beneficial Arthropods and Weed Seed Predation in Acorn Squash.

    Science.gov (United States)

    Quinn, N F; Brainard, D C; Szendrei, Z

    2016-12-01

    Conservation tillage combined with cover crops or mulching may enhance natural enemy activity in agroecosystems by reducing soil disturbance and increasing habitat structural complexity. In particular, weed seed predation can increase with vegetation cover and reduced tillage, indicating that mulches may improve the quality of the habitat for weed seed foraging. The purpose of this study was to quantify the effects of tillage and mulching for conservation biological control in cucurbit fields. The effects of mulch and reduced tillage on arthropods and rates of weed seed loss from arenas were examined in field trials on sandy soils in 2014 and 2015. Experimental factors included tillage and cover crop, each with two levels: strip-tillage or full-tillage, and cover crop mulch (rye residue) or no cover crop mulch (unmulched). Arthropod abundance on the crop foliage was not affected by tillage or cover crops. Contrary to expectations, epigeal natural enemies of insects and rates of weed seed removal either did not respond to treatments or were greater in full-tilled plots and plots without mulch. Our study demonstrates the potential importance of weed seed predators in reducing weed seedbanks in vegetable agroecosystems, and suggests that early-season tillage may not be detrimental to epigeal predator assemblages. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Crop residues quantification to obtain self-consumption compost in an organic garden

    Science.gov (United States)

    Lopez de Fuentes, Pilar; Lopez Merino, María; Remedios Alvir, María; Briz de Felipe, Teresa

    2013-04-01

    This research focuses on quantifying the crop residue left after the campaign fall/winter (2011) for the organic garden crops of Agricultural ETSI, located in practice fields, to get compost for self-generated residues arising from within their own fields. This compost is produced by mixing this material with an organic residues source animal. In this way the plant organic residues provided the nitrogen required for an appropriate C/N and the animal organic residues can provide the carbon amount required to achieve an optimal scenario. The garden has a surface area of 180 m2 which was cultured with different seasonal vegetables, different families and attending practices and species associations' rotations, proper of farming techniques. The organic material of animal origin referred to, is rest from sheep renew bed, sustained management support the precepts of organic farming and cottage belongs to practice fields too. At the end of crop cycle, we proceeded to the harvest and sorting of usable crop residues, which was considered as net crop residues. In each case, these residues were subjected to a cutting treatment by the action of a mincing machine and then weighed to estimate the amounts given by each crop. For the sheep bed residue 1m2 was collected after three months having renewed. It had been made by providing 84 kg of straw bales in July and introducing about 12 Kg each. The herd consisted of three females and one playe. Each one of them was feed 300g and 600 g of straw per day. Two alternating different pens were used to simulate a regime of semi-intensive housing. A balance on how much organic residue material was obtained at the end and how much was obtained in the compost process is discussed in terms of volume and nutrients content is discussed.

  1. Plant Residual Management in different Crop Rotations System on Potato Tuber Yield Loss Affected by Wireworms

    Directory of Open Access Journals (Sweden)

    A. Zarea Feizabadi

    2016-07-01

    Full Text Available Introduction: Selection a proper crop rotation based on environmental conservation rules is a key factor for increasing long term productivity. On the other hand, the major problem in reaching agricultural sustainability is lack of soil organic matter. Recently, a new viewpoint has emerged based on efficient use of inputs, environmental protection, ecological economy, food supply and security. Crop rotation cannot supply and restore plant needed nutrients, so gradually the productivity of rotation system tends to be decreased. Returning the plant residues to the soil helps to increase its organic matter and fertility in long-term period. Wireworms are multi host pests and we can see them in wheat and barley too. The logic way for their control is agronomic practices like as crop rotation. Wireworms’ population and damages are increased with using grasses and small seed gramineas in mild winters, variation in cropping pattern, reduced chemical control, and cover crops in winter. In return soil cultivation, crop rotation, planting date, fertilizing, irrigation and field health are the examples for the effective factors in reducing wireworms’ damage. Materials and Methods: In order to study the effect of crop rotations, residue management and yield damage because of wireworms’ population in soil, this experiment was conducted using four rotation systems for five years in Jolgeh- Rokh agricultural research station. Crop rotations were included, 1 Wheat monoculture for the whole period (WWWWW, 2 Wheat- wheat- wheat- canola- wheat (WWWCW, 3 Wheat- sugar beet- wheat- potato- wheat (WSWPW, 4 Wheat- maize- wheat- potato- wheat (WMWPW as main plots and three levels of returning crop residues to soil (returning 0, 50 and 100% produced crop residues to soil were allocated as sub plots. This experiment was designed as split plot based on RCBD design with three replications. After ending each rotation treatment, the field was sowed with potato cv. Agria

  2. Erratum to: Estimating the crop response to fertilizer nitrogen residues in long-continued field experiments

    DEFF Research Database (Denmark)

    Petersen, Jens; Thomsen, Ingrid Kaag; Mattson, L

    2012-01-01

    Knowledge of the cumulated effect of long-continued nitrogen (N) inputs is important for both agronomic and environmental reasons. However, only little attention has been paid to estimate the crop response to mineral fertilizer N residues. Before interpreting estimates for the crop response...... yield of spring barley decreased by an average of 5 kg DM/ha and the grain N offtake by 46 g N/ha for a decrease in the annual mineral N rate of 1 kg N/ha applied for more than three decades. Although statistically significant, the crop response to mineral fertilizer N residues was of minor importance...

  3. Burning crop residues under no-till in semi-arid land, Northern Spain - effects on soil organic matter, aggregation, and earthwor populations.

    NARCIS (Netherlands)

    Virto, I.; Imaz, M.J.; Enrique, A.; Hoogmoed, W.B.; Bescansa, P.

    2007-01-01

    Stubble burning has traditionally been used in semi-arid land for pest and weed control, and to remove the excess of crop residues before seeding in no-tillage systems. We compared differences in soil properties in a long-term (10 years) tillage trial on a carbonated soil in semi-arid north-east Spa

  4. Influence of cover crops and crop residue treatment on soil organic carbon stocks evaluated in Swedish long-term field experiments

    Science.gov (United States)

    Poeplau, Christopher; Bolinder, Martin A.; Börjesson, Gunnar; Kätterer, Thomas

    2015-04-01

    Soil organic carbon (SOC) stocks in agricultural soils are strongly controlled by management. In this study we quantified the effect of cover crops and crop residue management on SOC stocks in Swedish long-term experiments. Eight pairs of cover crop (undersown ryegrass) vs. no cover crop were investigated in Swedish long-term field experiments (16 to 24 years). Yields of the main crop were not affected by the cover crop. Cover crops significantly increased SOC stocks, with a mean carbon sequestration rate in all experiments (excluding one) of 0.32±0.29 Mg C ha-1 yr-1. Interestingly, this sequestration is similar to that estimated for a U.S.experiment, where ryegrass growth is much less temperature- and light-limited than under Swedish conditions. This sequestration rate is also the same as that recently reported for many other cover crops in a global meta-analysis but less than SOC changes in ley-dominated rotations which under Nordic conditions were shown to accumulate in average 0.5 Mg C ha-1 yr-1 more carbon compared to exclusively annual cropping systems. Thus, originally introduced in agricultural rotations to reduce nitrate leaching, cover crops are also an effective practice to increase SOC stocks, even at relatively high latitudes. The effect of crop residue treatment was studied in 16 pairs of straw incorporated (SI) vs. straw removed (SR) treatments in six Swedish long-term field experiments. Data series on SOC with 5-28 sampling dates during 27-53 years were analysed using ICBM, a dynamic SOC model. At five out of six sites, the humification coefficient for straw (hlitter; the fraction of straw C that is entering the slow C pool) was much smaller (0-0.09) than the ICBM default h-value for plant material estimated in previous studies (0.125). The derived hlitter-values and thus the stabilization of straw-derived carbon increased significantly with clay content. For an Italian site (with five pairs of SI vs. SR) that was used for model validation we found

  5. Nitrogen Transfer from Cover Crop Residues to Onion Grown under Minimum Tillage in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Leoncio de Paula Koucher

    2017-08-01

    Full Text Available ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and at harvest, young expanded onion leaves, complete plants, and samples from different soil layers were collected and analyzed for recovery of 15N-labeled residue. Oilseed radish decomposed faster than other residues and 4 % of residue N was recovered in leaves and bulbs at harvest, but in general, N in plant organs was derived from sources other than the cover crop residues. In addition, leaf N was in the proper range for all treatments and was adequately mobilized to the bases for bulbing. The N derived from decomposing residues contributed little to onion development and the use of these plants should be chosen based on their advantages for physical and biological soil quality.

  6. Nitrogen accumulation and residual effects of nitrogen catch crops

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1991-01-01

    The nitrogen accumulation in Italian ryegrass (Lolium multiflorum Lam.), perennial ryegrass (Lolium perenne L.), white mustard (Sinapis alba L.) and tansy phacelia (Phacelia tanacetifolia L.), under- or aftersown as nitrogen catch crops to spring barley (Hordeum vulgare L.) and field pea (Pisum s...

  7. Spatial Variability Mapping of Crop Residue Using Hyperion (EO-1 Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Abderrazak Bannari

    2015-06-01

    Full Text Available Soil management practices that maintain crop residue cover and reduce tillage improve soil structure, increase organic matter content in the soil, positively influence water infiltration, evaporation and soil temperature, and play an important role in fixing CO2 in the soil. Consequently, good residue management practices on agricultural land have many positive impacts on soil quality, crop production quality and decrease the rate of soil erosion. Several studies have been undertaken to develop and test methods to derive information on crop residue cover and soil tillage using empirical and semi-empirical methods in combination with remote sensing data. However, these methods are generally not sufficiently rigorous and accurate for characterizing the spatial variability of crop residue cover in agricultural fields. The goal of this research is to investigate the potential of hyperspectral Hyperion (Earth Observing-1, EO-1 data and constrained linear spectral mixture analysis (CLSMA for percent crop residue cover estimation and mapping. Hyperion data were acquired together with ground-reference measurements for validation purposes at the beginning of the agricultural season (prior to spring crop planting in Saskatchewan (Canada. At this time, only bare soil and crop residue were present with no crop cover development. In order to extract the crop residue fraction, the images were preprocessed, and then unmixed considering the entire spectral range (427 nm–2355 nm and the pure spectra (endmember. The results showed that the correlation between ground-reference measurements and extracted fractions from the Hyperion data using CLMSA showed that the model was overall a very good predictor for crop residue percent cover (index of agreement (D of 0.94, coefficient of determination (R2 of 0.73 and root mean square error (RMSE of 8.7% and soil percent cover (D of 0.91, R2 of 0.68 and RMSE of 10.3%. This performance of Hyperion is mainly due to the

  8. Farming Systems Research and Livestock Feed Development : the case of a project on feeding of crop residues in India

    NARCIS (Netherlands)

    Schiere, J.B.; Kiran Singh,; Boer, de A.J.

    2000-01-01

    Increased use of prime agricultural land for cropping and non-agricultural uses in many tropical countries implies that crop residues become more important as a source of feed for livestock. Traditionally, much research on crop residue feeding was done by focusing on laboratory measurements of feed

  9. Biochemical suitability of crop residues for cellulosic ethanol: disincentives to nitrogen fertilization in corn agriculture.

    Science.gov (United States)

    Gallagher, Morgan E; Hockaday, William C; Masiello, Caroline A; Snapp, Sieglinde; McSwiney, Claire P; Baldock, Jeffrey A

    2011-03-01

    Concerns about energy security and climate change have increased biofuel demand, particularly ethanol produced from cellulosic feedstocks (e.g., food crop residues). A central challenge to cropping for cellulosic ethanol is the potential environmental damage from increased fertilizer use. Previous analyses have assumed that cropping for carbohydrate in residue will require the same amount of fertilizer as cropping for grain. Using (13)C nuclear magnetic resonance, we show that increases in biomass in response to fertilization are not uniform across biochemical classes (carbohydrate, protein, lipid, lignin) or tissues (leaf and stem, grain, reproductive support). Although corn grain responds vigorously and nonlinearly, corn residue shows only modest increases in carbohydrate yields in response to high levels of fertilization (25% increase with 202 kg N ha(-1)). Lignin yields in the residue increased almost twice as much as carbohydrate yields in response to nitrogen, implying that residue feedstock quality declines as more fertilizer is applied. Fertilization also increases the decomposability of corn residue, implying that soil carbon sequestration becomes less efficient with increased fertilizer. Our results suggest that even when corn is grown for grain, benefits of fertilization decline rapidly after the ecosystem's N demands are met. Heavy application of fertilizer yields minimal grain benefits and almost no benefits in residue carbohydrates, while degrading the cellulosic ethanol feedstock quality and soil carbon sequestration capacity.

  10. Assessment of the energy potential of crop residues and animal wastes in Tanzania

    Directory of Open Access Journals (Sweden)

    Felichesmi Selestine Lyakurwa

    2016-12-01

    Full Text Available Energy access has a significant contribution to the social, economic and environmental dimensions of the human development. The access to clean and safe energy can improve the human health and quality of ecosystems by reducing the extent of pollution caused by use of inefficient cooking equipments and processes, and by slowing environmental degradation. In this paper Monte Carlo simulation was applied to evaluate the amount of crop residues available which provided the basis for the quantity of energy that can be generated from the crop residues and animal wastes in Tanzania. The amount of crop residues and animal wastes was estimated from the agricultural statistical data obtained from the Food and Agriculture Organization of the United Nations (FAO from 1961 – 2012. The analysis revealed the bioenergy potential of crop residues in Tanzania to be 5,714 TJ in 2012, which is extremely larger than the installed electric energy generation capacity of 1564 MW in 2013. Besides, the estimation of renewable energy potential of live animals indicated the ability to generate 1,397 TJ/year if exploited. Thus, effective utilization of crop residues and animal wastes without compromising the amount required for the soil fertility and animal feeds can contribute greatly to the access of safe and clean anergy for sustainable development of the rural and urban areas of Tanzania.

  11. Nitrous oxide and N-leaching losses from agricultural soil: Influence of crop residue particle size, quality and placement

    DEFF Research Database (Denmark)

    Ambus, P.; Jensen, E.S.; Robertson, G.P.

    2001-01-01

    Incorporation of crop residues provides a source of readily available C and N, and previous works indicate that farming strategies where crop residues are used for soil fertility purposes may lead to increased emissions of N2O. Information on the importance of different residue management on the ...

  12. Feasibility study for anaerobic digestion of agricultural crop residues. Dynatech report No. 1935

    Energy Technology Data Exchange (ETDEWEB)

    Ashare, E.; Buivid, M. G.; Wilson, E. H.

    1979-07-31

    The objective of this study was to provide cost estimates for the pretreatment/digestion of crop residues to fuel gas. A review of agricultural statistics indicated that the crop residues wheat straw, corn stover, and rice straw are available in sufficient quantity to provide meaningful supplies of gas. Engineering economic analyses were performed for digestion of wheat straw, corn stover, and rice straw for small farm-, cooperative-, and industrial scales. The small farm scale processed the residue from an average size US farm (400 acres), and the other sizes were two and three orders of magnitude greater. The results of the analyses indicate that the production of fuel gas from these residues is, at best, economically marginal, unless a credit can be obtained for digester effluent. The use of pretreatment can double the fuel gas output but will not be economically justifiable unless low chemical requirements or low cost chemicals can be utilized. Additional development is necessary in this area. Use of low cost hole-in-the-ground batch digestion results in improved economics for the small farm size digestion system, but not for the cooperative and industrial size systems. Recommendations arising from this study are continued development of autohydrolysis and chemical pretreatment of agricultural crop residues to improve fuel gas yields in an economically feasible manner; development of a low cost controlled landfill batch digestion process for small farm applications; and determination of crop residue digestion by-product values for fertilizer and refeed.

  13. Removal of Pharmaceutical residues by ferrate(VI.

    Directory of Open Access Journals (Sweden)

    Jia-Qian Jiang

    Full Text Available BACKGROUND: Pharmaceuticals and their metabolites are inevitably emitted into the waters. The adverse environmental and human health effects of pharmaceutical residues in water could take place under a very low concentration range; from several µg/L to ng/L. These are challenges to the global water industries as there is no unit process specifically designed to remove these pollutants. An efficient technology is thus sought to treat these pollutants in water and waste water. METHODOLOGY/MAJOR RESULTS: A novel chemical, ferrate, was assessed using a standard jar test procedure for the removal of pharmaceuticals. The analytical protocols of pharmaceuticals were standard solid phase extraction together with various instrumentation methods including LC-MS, HPLC-UV and UV/Vis spectroscopy. Ferrate can remove more than 80% of ciprofloxacin (CIP at ferrate dose of 1 mg Fe/L and 30% of ibuprofen (IBU at ferrate dose of 2 mg Fe/L. Removal of pharmaceuticals by ferrate was pH dependant and this was in coordinate to the chemical/physical properties of pharmaceuticals. Ferrate has shown higher capability in the degradation of CIP than IBU; this is because CIP has electron-rich organic moieties (EOM which can be readily degraded by ferrate oxidation and IBU has electron-withdrawing groups which has slow reaction rate with ferrate. Promising performance of ferrate in the treatment of real waste water effluent at both pH 6 and 8 and dose range of 1-5 mg Fe/L was observed. Removal efficiency of ciprofloxacin was the highest among the target compounds (63%, followed by naproxen (43%. On the other hand, n-acetyl sulphamethoxazole was the hardest to be removed by ferrate (8% only. CONCLUSIONS: Ferrate is a promising chemical to be used to treat pharmaceuticals in waste water. Adjusting operating conditions in terms of the properties of target pharmaceuticals can maximise the pharmaceutical removal efficiency.

  14. Crop residue management and fertilization effects on soil organic matter and associated biological properties.

    Science.gov (United States)

    Zhao, Bingzi; Zhang, Jiabao; Yu, Yueyue; Karlen, Douglas L; Hao, Xiying

    2016-09-01

    Returning crop residue may result in nutrient reduction in soil in the first few years. A two-year field experiment was conducted to assess whether this negative effect is alleviated by improved crop residue management (CRM). Nine treatments (3 CRM and 3 N fertilizer rates) were used. The CRM treatments were (1) R0: 100 % of the N using mineral fertilizer with no crop residues return; (2) R: crop residue plus mineral fertilizer as for the R0; and (3) Rc: crop residue plus 83 % of the N using mineral and 17 % manure fertilizer. Each CRM received N fertilizer rates at 270, 360, and 450 kg N ha(-1) year(-1). At the end of the experiment, soil NO3-N was reduced by 33 % from the R relative to the R0 treatment, while the Rc treatment resulted in a 21 to 44 % increase in occluded particulate organic C and N, and 80 °C extracted dissolved organic N, 19 to 32 % increase in microbial biomass C and protease activity, and higher monounsaturated phospholipid fatty acid (PLFA):saturated PLFA ratio from stimulating growth of indigenous bacteria when compared with the R treatment. Principal component analysis showed that the Biolog and PLFA profiles in the three CRM treatments were different from each other. Overall, these properties were not influenced by the used N fertilizer rates. Our results indicated that application of 17 % of the total N using manure in a field with crop residues return was effective for improving potential plant N availability and labile soil organic matter, primarily due to a shift in the dominant microorganisms.

  15. System Study: Residual Heat Removal 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-02-01

    This report presents an unreliability evaluation of the residual heat removal (RHR) system in two modes of operation (low-pressure injection in response to a large loss-of-coolant accident and post-trip shutdown-cooling) at 104 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant trends were identified in the RHR results.

  16. Fast Removal of Residual Water in Proton Spectra.

    Science.gov (United States)

    Vanhamme; Fierro; Van Huffel S; de Beer R

    1998-06-01

    Quantification of metabolites in 1H spectra is difficult because of the presence of an unwanted water signal. Preprocessing, or removing the water contribution of a 1H spectrum, in the time domain is usually done using the state-space approach HSVD. HSVD removes the residual water and its side lobes, thereby reducing the baseline for the metabolites of interest and allowing subsequent data analysis using more sophisticated nonlinear least squares algorithms. However, the HSVD algorithm is computationally expensive because it estimates the signal subspace using the singular value decomposition (SVD). We show here that replacing the SVD by a low-rank revealing decomposition speeds up the computations without affecting the accuracy of the wanted parameter estimates. Copyright 1998 Academic Press.

  17. Removal of coagulant aluminum from water treatment residuals by acid.

    Science.gov (United States)

    Okuda, Tetsuji; Nishijima, Wataru; Sugimoto, Mayo; Saka, Naoyuki; Nakai, Satoshi; Tanabe, Kazuyasu; Ito, Junki; Takenaka, Kenji; Okada, Mitsumasa

    2014-09-01

    Sediment sludge during coagulation and sedimentation in drinking water treatment is called "water treatment residuals (WTR)". Polyaluminum chloride (PAC) is mainly used as a coagulant in Japan. The recycling of WTR has been desired; one method for its reuse is as plowed soil. However, WTR reuse in this way is inhibited by the aluminum from the added PAC, because of its high adsorption capacity for phosphate and other fertilizer components. The removal of such aluminum from WTR would therefore be advantageous for its reuse as plowed soil; this research clarified the effect of acid washing on aluminum removal from WTR and on plant growth in the treated soil. The percentage of aluminum removal from raw WTR by sulphuric acid solution was around 90% at pH 3, the percentage decreasing to 40% in the case of a sun-dried sample. The maximum phosphate adsorption capacity was decreased and the available phosphorus was increased by acid washing, with 90% of aluminum removal. The enhancement of Japanese mustard spinach growth and the increased in plant uptake of phosphates following acid washing were observed.

  18. Effect of water content and organic carbon on remote sensing of crop residue cover

    Science.gov (United States)

    Serbin, G.; Hunt, E. R., Jr.; Daughtry, C. S. T.; McCarty, G. W.; Brown, D. J.; Doraiswamy, P. C.

    2009-04-01

    Crop residue cover is an important indicator of tillage method. Remote sensing of crop residue cover is an attractive and efficient method when compared with traditional ground-based methods, e.g., the line-point transect or windshield survey. A number of spectral indices have been devised for residue cover estimation. Of these, the most effective are those in the shortwave infrared portion of the spectrum, situated between 1950 and 2500 nm. These indices include the hyperspectral Cellulose Absorption Index (CAI), and advanced multispectral indices, i.e., the Lignin-Cellulose Absorption (LCA) index and the Shortwave Infrared Normalized Difference Residue Index (SINDRI), which were devised for the NASA Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor. Spectra of numerous soils from U.S. Corn Belt (Indiana and Iowa) were acquired under wetness conditions varying from saturation to oven-dry conditions. The behavior of soil reflectance with water content was also dependent on the soil organic carbon content (SOC) of the soils, and the location of the spectral bands relative to significant water absorptions. High-SOC soils showed the least change in spectral index values with increase in soil water content. Low-SOC soils, on the other hand, showed measurable difference. For CAI, low-SOC soils show an initial decrease in index value followed by an increase, due to the way that water content affects CAI spectral bands. Crop residue CAI values decrease with water content. For LCA, water content increases decrease crop residue index values and increase them for soils, resulting in decreased contrast. SINDRI is also affected by SOC and water content. As such, spatial information on the distribution of surface soil water content and SOC, when used in a geographic information system (GIS), will improve the accuracy of remotely-sensed crop residue cover estimates.

  19. Soil carbon storage and stratiifcation under different tillage/residue-management practices in double rice cropping system

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhong-du; ZHANG Hai-lin; S Batsile Dikgwatlhe; XUE Jian-fu; QIU Kang-cheng; TANG Hai-ming; CHEN fu

    2015-01-01

    The importance of soil organic carbon (SOC) sequestration in agricultural soils as climate-change-mitigating strategy has become an area of focus by the scientiifc community in relation to soil management. This study was conducted to determine the temporal effect of different til age systems and residue management on distribution, storage and stratiifcation of SOC, and the yield of rice under double rice (Oryza sativa L.) cropping system in the southern China. A til age experiment was conducted in the southern China during 2005–2011, including plow til age with residue removed (PT0), plow til age with residue retention (PT), rotary til age with residue retention (RT), and no-til with residue retention on the surface (NT). The soil samples were obtained at the harvesting of late rice in October of 2005, 2007 and 2011. Multiple-year residue return application signiifcantly increased rice yields for the two rice-cropping systems;yields of early and late rice were higher under RT than those under other til age systems in both years in 2011. Compared with PT0, SOC stocks were increased in soil under NT at 0–5, 5–10, 10–20, and 20–30 cm depths by 33.8, 4.1, 6.6, and 53.3%, respectively, in 2011. SOC stocks under RT were higher than these under other til age treatments at 0–30 cm depth. SOC stocks in soil under PT were higher than those under PT0 in the 0–5 and 20–30 cm soil layers. Therefore, crop residues played an important role in SOC management, and improvement of soil quality. In the 0–20 cm layer, the stratiifcation ratio (SR) of SOC fol owed the order NT>RT>PT>PT0;when the 0–30 cm layer was considered, NT also had the highest SR of SOC, but the SR of SOC under PT was higher than that under RT with a multiple-year til age practice. Therefore, the notion that conservation til age lead to higher SOC stocks and soil quality than plowed systems requires cautious scrutiny. Nevertheless, some beneifts associated with RT system present a greater

  20. Feasibility study for anaerobic digestion of agricultural crop residues. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ashare, E.; Buivid, M. G.; Wilson, E. H.

    1979-10-01

    This study provides cost estimates for the pretreatment/digestion of crop residues to fuel gas. Agricultural statistics indicate that the crop residues wheat straw, corn stover, and rice straw are available in sufficient quantity to provide meaningful supplies of gas. Engineering economic analyses were performed for digestion of sheat straw, corn stover, and rice straw for small farm, cooperative, and industrial scales. The results of the analyses indicate that the production of fuel gas from these residues is, at best, economically marginal, unless a credit can be obtained for digester effluent. The use of pretreatment can double the fuel gas output but will not be economically justifiable unless low chemical requirements or low-cost chemicals can be utilized. Use of low-cost hole-in-the-ground batch digestion results in improved economics for the small farm size digestion system, but not for the cooperative and industrial size systems. Recommendations arising from this study are continued development of autohydrolysis and chemical pretreatment of agricultural crop residues to improve fuel gas yields in an economically feasible manner; development of a low-cost controlled landfill batch digestion process for small farm applications; and determination of crop residue digestion by-product values for fertilizer and refeed.

  1. Fermentation Characteristics of Rice Crop Residue-Based Silage Treated by Epiphytic and Commercial LAB

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2012-04-01

    Full Text Available Two experiments were conducted to investigate the effects of addition of lactic acid bacteria (LAB inoculant from king grass and a commercial inoculant of L. plantarum on fermentation characteristics and nutrient digestibility of rice crop residue-based silage. In experiment 1, mixture of rice crop residue (RC, soybean curd residue (SC and cassava waste (CW in a 80 : 10 : 10 (on dry matter basis ratio was used as silage material. Four treatments silage were (A RC + SC + CW as a control; (B RC + SC + CW + LAB inoculant from king grass (2%, v/w ; (C RC + SC + CW + LAB inoculant from king grass (3%, v/w; (D RC + SC + CW + L. plantarum inoculant (2%, v/w. In experiment 2, six Kacang goats were used in a 6 × 3 Youden square experiment and fed elephant grass, rice straw, and rice crop residue-based silage. The results showed that crude protein (CP content in silages B, C, and D was slightly higher than silage A. Lactic acid concentration was significantly higher (P<0.01 in silages B and C compared to silage D. The pH value of control silage (A was higher (P<0.05 than silage treated with LAB inoculant. Rice crop residue-based silage had higher (P<0.01 digestibility of dry matter (DM, organic matter (OM, and CP than rice straw. It was concluded that addition of epiphytic LAB inoculant from king grass to rice crop residue resulting in a good fermentation quality of silage compared to addition of L. plantarum inoculant.

  2. Aluminum-Based Water Treatment Residue Reuse for Phosphorus Removal

    Directory of Open Access Journals (Sweden)

    Lai Yoke Lee

    2015-04-01

    Full Text Available Aluminum-based water treatment residue (Al-WTR generated during the drinking water treatment process is a readily available recycled material with high phosphorus (P adsorption capacity. The P adsorption capacity of Al-WTR generated from Singapore’s water treatment plant was evaluated with reference to particle size range, adsorption pH and temperature. Column tests, with WTR amendments in sand with and without compost, were used to simulate the bioretention systems. The adsorption rate decreased with increasing WTR sizes. Highest P adsorption capacity, 15.57 mg PO43−-P/g WTR, was achieved using fine WTR particles (>50% particles at less than 0.30 mm. At pH 4, the contact time required to reduce effluent P concentration to below the detectable range was half compared with pH 7 and 9. The adsorption rate observed at 40 ± 2 °C was 21% higher compared with that at 30 ± 2 °C. Soil mixes amended with 10% WTR and compost were able to maintain consistently high (90% total phosphorus (TP removal efficiency at a TP load up to 6.45 g/m3. In contrast, TP removal efficiencies associated with columns without WTR amendment decreased to less than 45% as the TP load increased beyond 4.5 g/m3. The results showed that WTR application is beneficial for enhanced TP removal in bioretention systems.

  3. Influence of crop residues on trifluralin mineralization in a silty clay loam soil.

    Science.gov (United States)

    Farenhorst, Annemieke

    2007-01-01

    Trifluralin is typically applied onto crop residues (trash, stubble) at the soil surface, or onto the bare soil surface after the incorporation of crop residues into the soil. The objective of this study was to quantify the effect of the type and amount of crop residues in soil on trifluralin mineralization in a Wellwood silty clay loam soil. Leaves and stubble of Potato (Solanum tuberosum) (P); Canola (Brassica napus) (C), Wheat (Triticum aestivum) (W), Oats (Avena sativa), (O), and Alfalfa (Medicago sativa) (A) were added to soil microcosms at rates of 2%, 4%, 8% and 16% of the total soil weight (25 g). The type and amount of crop residues in soil had little influence on the trifluralin first-order mineralization rate constant, which ranged from 3.57E-03 day(-1) in soil with 16% A to 2.89E-02 day(-1) in soil with 8% W. The cumulative trifluralin mineralization at 113 days ranged from 1.15% in soil with 16% P to 3.21% in soil with 4% C, again demonstrating that the observed differences across the treatments are not of agronomic or environmental importance.

  4. Magnitude of the residue analyses in specialty crops from experimental applications of triazole fungicides.

    Science.gov (United States)

    The IR-4 Project conducts the research required for the registration of pest control products on specialty crops such as fruits, vegetables, herbs, and others. The Tifton IR-4 Analytical Laboratory is one of the program’s five regional laboratories that conduct magnitude of the residue analyses on ...

  5. Investigation on emission factors of particulate matter and gaseous pollutants from crop residue burning

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Emission factors of particulate matter (PM), element carbon (EC), organic carbon (OC), SO2, NOx, CO, CO2, and ten ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO2-, NO3-, SO42-) were estimated from the domestic burning of four types of commonly produced crop residues in rural China: rice straw, wheat straw, corn stover, and cotton stalk, which were collected from the representative regions across China. A combustion tower was designed to simulate the cooking conditions under which the peasants burned their crop residues in rural China, to measure the emission factors. Results show that wheat straw has the highest emission factor for the total PM (8.75 g/kg) among the four crop residues, whereas, corn stover and wheat straw have the highest emission factor for EC (0.95 g/kg) and OC (3.46 g/kg), respectively. Corn stover also presents as having the highest emission factors of NO, NOx, and CO2 whereas, wheat straw, rice straw, and cotton stalk have the highest emission factors of NO2, SO2, and CO, respectively. The water-soluble ions, K+ and Cl-, have the highest emission factors from all the crops. Wheat straw has a relatively higher emission factor of cation species and F-, Cl-, NO2- than other residues.

  6. Residue management increases fallow water conservation and yield deficit irrigated crops grown in rotation with wheat

    Science.gov (United States)

    No-tillage (NT) residue management provides cover to increase precipitation capture compared with disk tillage (DT) or in the absence of a cover crop. Therefore, NT has the potential to reduce irrigation withdrawals from the declining Ogallala Aquifer. In a 4-year study, we quantified DT and NT effe...

  7. Activated Carbon Derived from Fast Pyrolysis Liquids Production of Agricultural Residues and Energy Crops

    Science.gov (United States)

    Fast pyrolysis is a thermochemical method that can be used for processing energy crops such as switchgrass, alfalfa, soybean straw, corn stover as well as agricultural residuals (broiler litter) for bio-oil production. Researchers with the Agriculture Research Service (ARS) of the USDA developed a 2...

  8. Effects of crop residue on soil and plant water evaporation in a dryland cotton system

    Science.gov (United States)

    Lascano, R. J.; Baumhardt, R. L.

    1996-03-01

    Dryland agricultural cropping systems emphasize sustaining crop yields with limited use of fertilizer while conserving both rain water and the soil. Conservation of these resources may be achieved with management systems that retain residues at the soil surface simultaneously modifying both its energy and water balance. A conservation practice used with cotton grown on erodible soils of the Texas High Plains is to plant cotton into chemically terminated wheat residues. In this study, the partitioning of daily and seasonal evapotranspiration ( E t) into soil and plant water evaporation was compared for a conventional and a terminated-wheat cotton crop using the numerical model ENWATBAL. The model was configured to account for the effects of residue on the radiative fluxes and by introducing an additional resistance to latent and sensible heat fluxes derived from measurements of wind speed and vapor conductance from a soil covered with wheat-stubble. Our results showed that seasonal E t was similar in both systems and that cumulative soil water evaporation was 50% of E t in conventional cotton and 31% of E t in the wheat-stubble cotton. Calculated values of E t were in agreement with measured values. The main benefit of the wheat residues was to suppress soil water evaporation by intercepting irradiance early in the growing season when the crop leaf area index (LAI) was low. In semiarid regions LAI of dryland cotton seldom exceeds 2 and residues can improve water conservation. Measured soil temperatures showed that early in the season residues reduced temperature at 0.1 m depth by as much as 5°C and that differences between systems diminished with depth and over time. Residues increased lint yield per unit of E t while not modifying seasonal E t and reducing cumulative soil water evaporation.

  9. System Study: Residual Heat Removal 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-12-01

    This report presents an unreliability evaluation of the residual heat removal (RHR) system in two modes of operation (low-pressure injection in response to a large loss-of-coolant accident and post-trip shutdown-cooling) at 104 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing trends were identified in the RHR results. A highly statistically significant decreasing trend was observed for the RHR injection mode start-only unreliability. Statistically significant decreasing trends were observed for RHR shutdown cooling mode start-only unreliability and RHR shutdown cooling model 24-hour unreliability.

  10. Air Toxics Emissions from Open Burning of Crop Residues in Southeast Asia

    Science.gov (United States)

    KIM Oanh, N. T.; Permadi, D. A.; Hopke, P. K.; Smith, K. R.; Nguyet, D. A.

    2016-12-01

    Agricultural crops production in Southeast Asia (SEA) increases annually to meet domestic consumption of growing population and also for export. Crop residue open burning (CROB) is commonly practiced by farmers to quickly dispose of huge amounts of the agricultural waste, such as rice straw, generated after each crop cycle. This CROB activity emits various toxic air pollutants as well as short-lived climate pollutants such as black carbon particles. Our study focused on quantifying the 2015 annual emissions of semi-volatile organic compounds including polycyclic aromatic hydrocarbons (PAHs), dioxins/furans (PCDD/PCDF), organochlorine pesticides (OCP), along with other conventional trace gases, particulate matter, and greenhouse gases from CROB in 10 major agricultural crop producing SEA countries. Crop production statistics and current field OB practices were gathered from our primary surveys and relevant secondary data sources. Emission factors for rice straw and maize residue burning were taken mainly from our measurements in Thailand while for other crops relevant published data were used. The best emission estimates of air toxics from CROB in SEA were 112 g-TEQ/yr of PCDD/PCDF, 33 t/yr of OCP, and 25 Gg/yr of total PAH of which the well-known carcinogenic benzo[a]pyrene was 0.3 Gg/yr. The CROB of rice production had the highest shares of emissions (33-95%) among considered 8 crop types. Indonesia was the top contributor to the total SEA emissions (30-45%) followed by Vietnam (16-26%), Thailand (6-22%) and Myanmar (5-18%). The spatial distributions of emissions, 0.1º x 0.1º, for each specie were prepared using MODIS land cover data. Temporally, higher emissions were observed in the harvesting months of the main rice crops. This emissions database can be used in regional air quality modeling studies to assess the impacts of CROB activity and to promote non-open burning alternatives.

  11. RESIDUAL ACTIVITY OF HERBICIDES APPLIED TO COTTON ON CROPS CULTIVATED IN SUCCESSION

    Directory of Open Access Journals (Sweden)

    ELIEZER ANTONIO GHENO

    2016-01-01

    Full Text Available Herbicides with high persistence in soil can cause problems for crops sown in succession to their application. Thus, the aim of this study was to estimate, in greenhouse conditions, the safe period of time after application of preemergent herbicides used on cotton crops (isolated or in mixtures for the crops grown in succession (bean, corn, and soybean. The experimental design was completely randomized in a factorial scheme (5 x 11 + 1, with five repetitions. For each experiment, treatments combined different time periods between herbicide application and sowing of crops (280, 210, 140, 70, and 0 days before sowing of crops with eleven herbicide treatments: fomesafen (625 g ha - 1 prometryne (1250 g ha - 1 , diuron (1250 g ha - 1 , S - metolachlor (768 g ha - 1 , clomazone (1000 g ha - 1 , fomesafen + prometryne (625 + 1250 g ha - 1 , fomesafen + diuron (625 + 1250 g ha - 1 , fomesafen + S - metolachlor (625 + 768 g ha - 1 , fomesafen + clomazone (625 + 1000 g ha - 1 , fomesafen + clomazone + diuron (625 + 1000 + 1250 g ha - 1 , and fomesafen + clomazone + prometryne (625 + 1000 + 1250 g ha - 1 , plus an untreated control. Applications of diuron showed the greatest persistence, causing the largest carryover effects for the three crops evaluated. The other treatments showed residual effects or affected crop development when sowings were performed up to 70 days after application. At later periods no significant damage was observed.

  12. Assessment of maturity indices of rock phosphate enriched composts using variable crop residues.

    Science.gov (United States)

    Moharana, P C; Biswas, D R

    2016-12-01

    This study aimed to asses maturity indices of rock phosphate enriched composts using crop residues having variable C/N ratios. There were distinct differences in concentration of NH4(+)-N, NO3(-)-N, Olsen-P and NH4OAc-K for composts generated from different crop residues, the highest being in rice straw. Water soluble P varied from 3.47-4.45% of total P, while citrate soluble P varied from 32.7-54.0% of total P. Rice straw composts showed lower C/N, WSC/Org-N and E4/E6 ratio and higher germination index indicating that they are well-matured and stabilized compost. The relative order of performance of crop residues in aggrading compost quality was chickpea stover>rice straw>mustard stover>wheat straw>tree leaves. The results demonstrated that all the enriched composts had higher contents of available nutrients and quality indices, indicating that enriched composts could be used to substitute costly chemical fertilizers for crop production.

  13. Pesticide residues in passifloras crops in regions of high production in Colombia

    Directory of Open Access Journals (Sweden)

    Dario A. Bastidas

    2013-08-01

    Full Text Available As one of the most bio-diverse countries in the world, Colombia boasts a wide diversity of highly palatable tropical fruits. Even though Colombian fruit production has primarily targeted the domestic market, several fruit species, such as passion fruit (PassifloraSpp, are steadily gaining ground in the broader international arena.  Production of these crops and respond to raising domestic and international demand, many Colombian small-scale farmers use pesticides for pest and disease control. Inadequate use of pesticides could possibly entail public health risks, environmental contamination and ultimately interfere with international trade. Surveys were carried out to passifloras producers of three spices of passiflora crops, yellow passion fruit, sweet passion fruit and purple passion fruit  from the largest producers municipalities in Colombia with the aim to know the integrate pest control and agricultural practices related with pesticides applied in the crops. Ramdomly sampling was realized and samples were analyzed by multiresidue analysis methodology validated in the laboratory and based on IAEA-QuEChERS method. With the results of survey and laboratory analysis it is showed the presence of pesticide residues that exceed maximum residue limits in some samples and the pesticides identified in the samples correspond to those used by farmers. It was found that the presence of residues is mainly due to the shortcomings in the proper use of agricultural practices related primarily to the implementation of agricultural products no registered for such crops.

  14. Determination of crop residues and the physical and mechanical properties of soil in different tillage systems

    Directory of Open Access Journals (Sweden)

    P Ahmadi Moghaddam

    2016-04-01

    Full Text Available Introduction: Monitoring and management of soil quality is crucial for sustaining soil function in ecosystem. Tillage is one of the management operations that drastically affect soil physical quality. Conservation tillage methods are one of the efficient solutions in agriculture to reduce the soil erosion, air pollution, energy consumption, and the costs, if there is a proper management on the crop residues. One of the serious problems in agriculture is soil erosion which is rapidly increased in the recent decades as the intensity of tillage increases. This phenomenon occurs more in sloping lands or in the fields which are lacking from crop residues and organic materials. The conservation tillage has an important role in minimizing soil erosion and developing the quality of soil. Hence, it has attracted the attention of more researchers and farmers in the recent years. Materials and Methods: In this study, the effect of different tillage methods has been investigated on the crop residues, mechanical resistance of soil, and the stability of aggregates. This research was performed on the agricultural fields of Urmia University, located in Nazloo zone in 2012. Wheat and barley were planted in these fields, consecutively. The soil texture of these fields was loamy clay and the factorial experiments were done in a completely randomized block design. In this study, effect of three tillage systems including tillage with moldboard (conventional tillage, tillage with disk plow (reduced tillage, chisel plow (minimum tillage and control treatment on some soil physical properties was investigated. Depth is second factor that was investigated in three levels including 0-60, 60-140, and 140-200 mm. Moreover, the effect of different percentages of crop residues on the rolling resistance of non-driving wheels was studied in a soil bin. The contents of crop residues have been measured by using the linear transects and image processing methods. In the linear

  15. The influence of crop residues in vertical soil mobility of potassium

    Directory of Open Access Journals (Sweden)

    Osmar Rodrigues Brito

    2014-12-01

    Full Text Available This study has been developed to evaluate the influence of applying different types and doses of crop residues on potassium (K mobility in soil columns. Rhodic Haplustox samples were collected at depths of 0.0-0.10, 0.10-0.20 and 0.20-0.30 m and used to create such soil columns, keeping the same profile distribution. The experimental design was randomized with three replications and the treatments resulted in a 4x4 factorial design, 4 types of crop residues (brachiaria+sunflower; Mix (cultivated radish+oat+winter vetch; cultivated radish and wheat and 4 doses of residues (0, 10, 15, and 20 Mg ha-1. The grinded and dried residues were applied to the surface of the columns, which were then irrigated with distilled water and incubated for 10 days to stabilize the reactions. After incubation, the soil columns were disassembled and separated into 0.05 m layers (0.0-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20, 0.20-0.25 and 0.25-0.30 m. The samples of each layer were dried, sieved and analyzed to determine the amount of exchangeable K. The results obtained indicated that surface application of crop residues alters soil levels of exchangeable potassium, especially in the 0.0-0.05 m layer. Increases in residue doses may cause a significant and linear increase in exchangeable K content in the 0.0-0.05, 0.05-0.10 and 0.10-0.15 m soil layers. Superficial application of residues of cultivated radish and Mix produced the largest increases in levels of exchangeable K, reaching depths of 0.30 m. Increases in potassium adsorption in the soil surface layers reduces the need for potassium fertilization and can reduce production costs and environmental pollution.

  16. Effects of bioreactor retention time on aerobic microbial decomposition of CELSS crop residues

    Science.gov (United States)

    Strayer, R. F.; Finger, B. W.; Alazraki, M. P.

    1997-01-01

    The focus of resource recovery research at the KSC-CELSS Breadboard Project has been the evaluation of microbiologically mediated biodegradation of crop residues by manipulation of bioreactor process and environmental variables. We will present results from over 3 years of studies that used laboratory- and breadboard-scale (8 and 120 L working volumes, respectively) aerobic, fed-batch, continuous stirred tank reactors (CSTR) for recovery of carbon and minerals from breadboard grown wheat and white potato residues. The paper will focus on the effects of a key process variable--bioreactor retention time--on response variables indicative of bioreactor performance. The goal is to determine the shortest retention time that is feasible for processing CELSS crop residues, thereby reducing bioreactor volume and weight requirements. Pushing the lower limits of bioreactor retention times will provide useful data for engineers who need to compare biological and physicochemical components. Bioreactor retention times were manipulated to range between 0.25 and 48 days. Results indicate that increases in retention time lead to a 4-fold increase in crop residue biodegradation, as measured by both dry weight losses and CO_2 production. A similar overall trend was also observed for crop residue fiber (cellulose and hemicellulose), with a noticeable jump in cellulose degradation between the 5.3 day and 10.7 day retention times. Water-soluble organic compounds (measured as soluble TOC) were appreciably reduced by more than 4-fold at all retention times tested. Results from a study of even shorter retention times (down to 0.25 days), in progress, will also be presented.

  17. Unexpected high decomposition of legume residues in dry season soils from tropical coffee plantations and crop lands

    OpenAIRE

    Abera, Girma; Wolde-Meskel, Endalkachew; Bakken, Lars

    2014-01-01

    International audience; Crop residues are essential fertilizer source of low-input farming systems in Sub-Saharan Africa. However, crop residues provide nutrients only if they decompose in the soil. Decomposition is assumed to be very low during the dry season due to the scarcity of water, but there are few quantitative knowledge on decomposition under such conditions. Therefore, we studied the decomposition of legume residues, haricot bean (Phaseolus vulgaris L.), and pigeon pea (Cajanus caj...

  18. A Multi-Factor Analysis of Sustainable Agricultural Residue Removal Potential

    Energy Technology Data Exchange (ETDEWEB)

    Jared Abodeely; David Muth; Paul Adler; Eleanor Campbell; Kenneth Mark Bryden

    2012-10-01

    Agricultural residues have significant potential as a near term source of cellulosic biomass for bioenergy production, but sustainable removal of agricultural residues requires consideration of the critical roles that residues play in the agronomic system. Previous work has developed an integrated model to evaluate sustainable agricultural residue removal potential considering soil erosion, soil organic carbon, greenhouse gas emission, and long-term yield impacts of residue removal practices. The integrated model couples the environmental process models WEPS, RUSLE2, SCI, and DAYCENT. This study uses the integrated model to investigate the impact of interval removal practices in Boone County, Iowa, US. Residue removal of 4.5 Mg/ha was performed annually, bi-annually, and tri-annually and were compared to no residue removal. The study is performed at the soil type scale using a national soil survey database assuming a continuous corn rotation with reduced tillage. Results are aggregated across soil types to provide county level estimates of soil organic carbon changes and individual soil type soil organic matter content if interval residue removal were implemented. Results show interval residue removal is possible while improving soil organic matter. Implementation of interval removal practices provide greater increases in soil organic matter while still providing substantial residue for bioenergy production.

  19. Relationship between physicochemical properties and maximum residue levels and tolerances of crop-protection products for crops set by the USA, European Union and Codex.

    Science.gov (United States)

    Thorbek, P; Hyder, K

    2006-08-01

    Residues on foodstuffs resulting from the use of crop-protection products are a function of many factors, e.g. environmental conditions, dissipation and application rate, some of which are linked to the physicochemical properties of the active ingredients. Residue limits (maximum residue levels (MRLs) and tolerances) of fungicides, herbicides and insecticides set by different regulatory authorities are compared, and the relationship between physicochemical properties of the active ingredients and residue limits are explored. This was carried out using simple summary statistics and artificial neural networks. US tolerances tended to be higher than European Union MRLs. Generally, fungicides had the highest residue limits followed by insecticides and herbicides. Physicochemical properties (e.g. aromatic proportion, non-carbon proportion and water solubility) and crop type explained up to 50% of the variation in residue limits. This suggests that physicochemical properties of the active ingredients may control important aspects of the processes leading to residues.

  20. Conservation agriculture increases soil organic carbon and residual water content in upland crop production systems

    Directory of Open Access Journals (Sweden)

    Victor B. Ella

    2016-01-01

    Full Text Available Conservation agriculture involves minimum soil disturbance, continuous ground cover, and diversified crop rotations or mixtures. Conservation agriculture production systems (CAPS have the potential to improve soil quality if appropriate cropping systems are developed. In this study, five CAPS including different cropping patterns and cover crops under two fertility levels, and a plow-based system as control, were studied in a typical upland agricultural area in northern Mindanao in the Philippines. Results showed that soil organic carbon (SOC at 0- 5-cm depth for all CAPS treatments generally increased with time while SOC under the plow-based system tended to decline over time for both the high (120, 60 and 60 kg N P K ha-1 and moderate (60-30-30 kg N P K ha-1 fertility levels. The cropping system with maize + Stylosanthes guianensis in the first year followed by Stylosanthes guianensis and fallow in the second year, and the cassava + Stylosanthes guianensis exhibited the highest rate of SOC increase for high and moderate fertility levels, respectively. After one, two, and three cropping seasons, plots under CAPS had significantly higher soil residual water content (RWC than under plow-based systems. Results of this study suggest that conservation agriculture has a positive impact on soil quality, while till systems negatively impact soil characteristics.

  1. Greenhouse crop residues: Energy potential and models for the prediction of their higher heating value

    Energy Technology Data Exchange (ETDEWEB)

    Callejon-Ferre, A.J.; Lopez-Martinez, J.A.; Manzano-Agugliaro, F. [Departamento de Ingenieria Rural, Universidad de Almeria, Ctra. Sacramento s/n, La Canada de San Urbano, 04120 Almeria (Spain); Velazquez-Marti, B. [Departamento de Ingenieria Rural y Agroalimentaria, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2011-02-15

    Almeria, in southeastern Spain, generates some 1,086,261 t year{sup -1} (fresh weight) of greenhouse crop (Cucurbita pepo L., Cucumis sativus L., Solanum melongena L., Solanum lycopersicum L., Phaseoulus vulgaris L., Capsicum annuum L., Citrillus vulgaris Schrad. and Cucumis melo L.) residues. The energy potential of this biomass is unclear. The aim of the present work was to accurately quantify this variable, differentiating between crop species while taking into consideration the area they each occupy. This, however, required the direct analysis of the higher heating value (HHV) of these residues, involving very expensive and therefore not commonly available equipment. Thus, a further aim was to develop models for predicting the HHV of these residues, taking into account variables measured by elemental and/or proximate analysis, thus providing an economically attractive alternative to direct analysis. All the analyses in this work involved the use of worldwide-recognised standards and methods. The total energy potential for these plant residues, as determined by direct analysis, was 1,003,497.49 MW h year{sup -1}. Twenty univariate and multivariate equations were developed to predict the HHV. The R{sup 2} and adjusted R{sup 2} values obtained for the univariate and multivariate models were 0.909 and 0.946 or above respectively. In all cases, the mean absolute percentage error varied between 0.344 and 2.533. These results show that any of these 20 equations could be used to accurately predict the HHV of crop residues. The residues produced by the Almeria greenhouse industry would appear to be an interesting source of renewable energy. (author)

  2. Removal of nitrogen leaching from vegetable crops in constructed wetlands

    NARCIS (Netherlands)

    Haan, de J.J.; Clevering, O.A.; Schoot, van der J.R.; Verstegen, H.A.G.

    2008-01-01

    Vegetable growing leads to high nitrogen emissions. In the Netherlands, nitrogen emissions can hardly be reduced by reducing fertilization without risks for yield and quality loss. An alternative measure to reduce emissions is to collect nitrate-rich drain water and remove nitrate from the drain

  3. Residues of sugar cane crop and its effects on the epigeic invertebrate fauna
    Resíduos da cultura da cana-de-açúcar e seus efeitos sobre a fauna invertebrada epigéica

    OpenAIRE

    Júlio César Salton; Alex Ramos Costa; Clovis Daniel Borges; Irzo Isaac Rosa Portilho; Fábio Martins Mercante

    2011-01-01

    This study aimed to evaluate the effect of the availability of sugar cane residues on the epigeic invertebrate fauna. The evaluations were made after cane sugar harvest f, considering three levels of residues: 0% (total removal of residues from the soil surface), 50% (removal of half of the waste in the plots, the dry mass of 7.6 Mg ha-1) and 100% (keeping track of residues produced, dry mass of 16.9 Mg ha-1). A fragment of native vegetation in the region, located close to the sugar cane crop...

  4. Pesticides residues in okra (non-target crop) grown close to a watermelon farm in Ghana.

    Science.gov (United States)

    Essumang, D K; Asare, E A; Dodoo, D K

    2013-09-01

    The study looked at the levels of pesticides in okra grown close to a watermelon farm herein referred to as a non-target crop. The watermelon received some pesticide application in the course of its cultivation, and the okra which was not meant to be sprayed was also affected by the pesticide. About 500 okra samples were collected for a period of 6 weeks and pesticides extracted with 1:1 n-hexane and dichloromethane which was analysed with Agilent 2222 GC/MS coupled with 389 auto-sampler. The results confirmed accumulation of significant levels of pesticides in the non-target crop (okra grown close to watermelon farm). Levels of organochlorine pesticides ranged from 3.10 to 7.60 μg/kg whilst the organophosphorus pesticides had levels ranging from 2.80 to 2016.80 μg/kg. The synthetic pyrethroid pesticide mean levels also ranged from 0.10 to 4.10 μg/kg and were below World Health Organization/Food and Agriculture Organization-recommended residue levels, and though not appearing to constitute a grave threat to life, their occurrence is a concern, and pre-emptive techniques must be developed to thwart the contaminations. Though the non- target crop was not treated directly with the pesticides, some level of contamination with organochlorine and organophosphorus pesticides persisted in the crops. It can be inferred that application of pesticides affected the adjoining crops, meaning that inter-cropping and mix-cropping might not be acceptable when one of the crops requires pesticide application. It is important for the farmers to be trained to ensure proper application of pesticide to minimise its impact on the health of consumers.

  5. Variations in thematic mapper spectra of soil related to tillage and crop residue management - Initial evaluation

    Science.gov (United States)

    Seeley, M. W.; Ruschy, D. L.; Linden, D. R.

    1983-01-01

    A cooperative research project was initiated in 1982 to study differences in thematic mapper spectral characteristics caused by variable tillage and crop residue practices. Initial evaluations of radiometric data suggest that spectral separability of variably tilled soils can be confounded by moisture and weathering effects. Separability of bare tilled soils from those with significant amounts of corn residue is enhanced by wet conditions, but still possible under dry conditions when recent tillage operations have occurred. In addition, thematic mapper data may provide an alternative method to study the radiant energy balance at the soil surface in conjunction with variable tillage systems.

  6. Photo-fermentative hydrogen production from crop residue: A mini review.

    Science.gov (United States)

    Zhang, Quanguo; Wang, Yi; Zhang, Zhiping; Lee, Duu-Jong; Zhou, Xuehua; Jing, Yanyan; Ge, Xumeng; Jiang, Danping; Hu, Jianjun; He, Chao

    2017-04-01

    Photofermentative hydrogen production from crop residues, if feasible, can lead to complete conversion of organic substances to hydrogen (and carbon dioxide). This mini review lists the studies on photofermentative hydrogen production using crop residues as feedstock. Pretreatment methods, substrate structure, mechanism of photosynthetic bacteria growth and metabolism were discussed. Photofermentative hydrogen production from pure culture, consortia and mutants, and the geometry, light sources, mass transfer resistances and the operational strategies of the photo-bioreactor were herein reviewed. Future studies of regulation mechanism of photosynthetic bacteria, such as highly-efficient strain breeding and gene reconstruction, and development of new-generation photo-bioreactor were suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Spatial decision support system to evaluate crop residue energy potential by anaerobic digestion.

    Science.gov (United States)

    Escalante, Humberto; Castro, Liliana; Gauthier-Maradei, Paola; Rodríguez De La Vega, Reynel

    2016-11-01

    Implementing anaerobic digestion (AD) in energy production from crop residues requires development of decision tools to assess its feasibility and sustainability. A spatial decision support system (SDSS) was constructed to assist decision makers to select appropriate feedstock according to biomethanation potential, identify the most suitable location for biogas facilities, determine optimum plant capacity and supply chain, and evaluate associated risks and costs. SDSS involves a spatially explicit analysis, fuzzy multi-criteria analysis, and statistical and optimization models. The tool was validated on seven crop residues located in Santander, Colombia. For example, fique bagasse generates about 0.21millionm(3)CH4year(-1) (0.329m(3)CH4kg(-1) volatile solids) with a minimum profitable plant of about 2000tonyear(-1) and an internal rate of return of 10.5%. SDSS can be applied to evaluate other biomass resources, availability periods, and co-digestion potential.

  8. Emission factors of gaseous carbonaceous species from residential combustion of coal and crop residue briquettes

    Institute of Scientific and Technical Information of China (English)

    Qin WANG; Chunmei GENG; Sihua LU; Wentai CHEN; Min SHAO

    2013-01-01

    Experiments were performed to measure the emission factors (EFs) of gaseous carbonaceous species, such as CO2, CO, CH4, and non-methane volatile organic compounds (NMVOCs), from the combustion of five types of coal of varying organic maturity and two types of biomass briquettes under residential burning conditions. Samples were collected in stainless steel canisters and 2,4- dinitrophenylhydrazine (DNPH) cartridges and were analyzed by GC FID/MS and HPLC, respectively. The EFs from crop residue briquette burning were generally higher than those from coals, with the exception of CO2. The dominant NMVOC species identified in coal smoke were carbonyls (41.7%), followed by C2 unsaturated hydrocarbons (29.1%) and aromatics (12.1%), while C2 unsaturated hydrocarbons were the dominant species (68.9%) emitted from the combustion of crop residue briquettes, followed by aromatics (14.4%). A comparison of burning normal crop residues in stoves and the open field indicated that briquettes emitted a larger proportion of ethene and acetylene. Both combustion efficiency and coal organic maturity had a significant impact on NMVOC EFs from burning coal: NMVOC emissions increased with increasing coal organic maturity but decreased as the combustion efficiency improved. Emissions from the combustion of crop residue briquettes from stoves occurred mainly during the smoldering process, with low combustion efficiency. Therefore, an improved stove design to allow higher combustion efficiency would be beneficial for reducing emissions of carbonaceous air pollutants.

  9. Tillage, cover-crop residue management, and irrigation incorporation impact on fomesafen runoff.

    Science.gov (United States)

    Potter, Thomas L; Truman, Clint C; Webster, Theodore M; Bosch, David D; Strickland, Timothy C

    2011-07-27

    Intensive glyphosate use has contributed to the evolution and occurrence of glyphosate-resistant weeds that threaten production of many crops. Sustained use of this highly valued herbicide requires rotation and/or substitution of herbicides with different modes of action. Cotton growers have shown considerable interest in the protoporphyrinogen oxidase inhibitor, fomesafen. Following registration for cotton in 2008, use has increased rapidly. Environmental fate data in major use areas are needed to appropriately evaluate risks. Field-based rainfall simulation was used to evaluate fomesafen runoff potential with and without irrigation incorporation in a conventional tillage system (CT) and when conservation tillage (CsT) was practiced with and without cover crop residue rolling. Without irrigation incorporation, relatively high runoff, about 5% of applied, was measured from the CT system, indicating that this compound may present a runoff risk. Runoff was reduced by >50% when the herbicide was irrigation incorporated after application or when used with a CsT system. Data indicate that these practices should be implemented whenever possible to reduce fomesafen runoff risk. Results also raised concerns about leaching and potential groundwater contamination and crop injury due to rapid washoff from cover crop residues in CsT systems. Further work is needed to address these concerns.

  10. Effects of residual disinfectant on soil and lettuce crop irrigated with chlorinated water.

    Science.gov (United States)

    Lonigro, A; Montemurro, N; Laera, G

    2017-04-15

    The accidental or continuous release of residual chlorine in water reclaimed for irrigational purposes could compromise the crop yield and increase the load of toxic organo-halogenated compounds, posing additional risks for environment and human health. This study was aimed at assessing the consequences of using chlorinated water for irrigating lettuce crops grown in pots with two different types of soil. The results show that the accumulation of extractable organo-halogenated compounds (EOX) in soil, roots and leaves is directly related to the chlorine concentration in the irrigation water. The accumulation of EOX in sandy soils is not significant, while it reached up to 300% of the control in the silty-clay soil, demonstrating that the phenomenon is linked to the organic matter content in the soil. The accumulation of EOX in the soil appears to play a significant role in subsequent bioaccumulation in cultures irrigated with tap water (long term memory effect). Chloramines also demonstrated to have similar impacts as the free chlorine from hypochlorite. The consistent bioaccumulation of 400-700μgClkg(-1) of EOX in the leaves of crops irrigated with just 0.2mgClL(-1) of residual chlorine, as compared to levels below the detection limit of 75μgClkg(-1) in the control crops, evidences the potential impact on food chain and human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Characterization of cyclodextrin containing nanofilters for removal of pharmaceutical residues.

    Science.gov (United States)

    Jurecska, Laura; Dobosy, Péter; Barkács, Katalin; Fenyvesi, Éva; Záray, Gyula

    2014-09-01

    Due to the increasing amount of persistent organic pollutants (POPs) in general and pharmaceutical residues in particular in municipal wastewater, the efficiency of water treatment technologies should be improved. Following the biological treatment of wastewater nanofiltration offers a possible way for the removal of POPs. In this study β-cyclodextrin containing nanofilters having different chemical composition and thickness (1.5-3.5mm) were investigated. For their characterization, their adsorption capacity was determined applying ibuprofen containing model solution and total organic carbon (TOC) analyzer. It could be established that the regeneration of nanofilters with ethanol and the application of inorganic additives (NaCl, NaHCO3, NH4HCO3) increased the adsorption capacity of nanofilters. The best results were achieved with chemical composition of 30m/m% β-cyclodextrin polymer beads and 70m/m% ultra-high molecular weight polyethylene in the presence of 12mmol ammonium hydrogen carbonate/nanofilter. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Nitrogen-to-Protein Conversion Factors for Crop Residues and Animal Manure Common in China.

    Science.gov (United States)

    Chen, Xueli; Zhao, Guanglu; Zhang, Yang; Han, Lujia; Xiao, Weihua

    2017-10-02

    Accurately determining protein content is essential in exploiting biomass as feed and fuel. A survey of biomass samples in China indicated protein contents from 2.65 to 3.98 % for crop residues and from 6.07 to 10.24 % for animal manure. Conversion factors based on amino acid nitrogen (kA) ranged from 5.42 to 6.00 for the former and from 4.78 to 5.36 for the latter, indicating that the traditional factor of 6.25 is not suitable for biomass samples. On the other hand, conversion factors from Kjeldahl nitrogen (kP) ranged from 3.97 to 4.57 and from 2.76 to 4.31 for crop residues and animal manure, respectively. Of note, conversion factors were strongly affected by amino acid composition and levels of nonprotein nitrogen. Thus, kP values of 4.23 for crop residues, 4.11 for livestock manure, and 3.11 for poultry manure are recommended to better estimate protein content from total nitrogen.

  13. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Cassigneul, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Benoit, P.; Bergheaud, V.; Dumeny, V.; Etiévant, V. [INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Goubard, Y. [AgroParisTech, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Maylin, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); Justes, E. [INRA, UMR 1248 AGIR Auzeville — BP 52 627, 31 326, Castanet-Tolosan cedex (France); Alletto, L. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France)

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of {sup 14}C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. {sup 14}C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH{sub 4}OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends {sup 14}C-glyphosate degradation half-life from 7 to 28 days depending on the CC. {sup 14}C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity. - Highlights: • Glyphosate sorption on cover crop residues increases with their decomposition degree. • Glyphosate degradation and mineralization are lower in mulch than in soil. • Nonextractable residue formation is one of the main dissipation pathways of glyphosate in cover crop mulch.

  14. Methods to enhance hydrolysis during one and two-stage anaerobic digestion of energy crops and crop residues

    Energy Technology Data Exchange (ETDEWEB)

    Jagadabhi, P. S.

    2011-07-01

    The objective of this thesis was to evaluate methods to enhance hydrolysis (measured as specific SCOD production, g SCOD g-1 VS) during one and two-stage anaerobic digestion (AD) of energy crops and crop residues. Addition of macro (NH{sub 4}Cl), micro nutrients (Fe, Ni, Co and Mo) and leachate replacement during mono-digestion of grass silage in one-stage leach bed reactors (LBRs) enhanced hydrolysis by 18 % (0.56 g SCOD g-1 VS), 7 % (0.45 g SCOD g-1 VS) and 34 % (0.51 g SCOD g-1 VS) respectively compared to respective controls. On the other hand, creating micro-aerobic conditions (at 1 l min-1, 2.5 l of air) did not improve hydrolysis but enhanced VFA production by 4 fold (from 2.2 g l-1 to 9 g l-1). Application of rumen cultures improved hydrolysis by 10 % (0.33 g SCOD g-1 VS) more than control (0.30 g SCOD g-1 VS). Similarly, during two-stage AD in LBR-UASB reactor configuration leachate replacement enhanced hydrolysis in cucumber and grass silage (0.5 g SCOD g-1 VS) than in tomato and common reed (0.35 and 0.15 g SCOD g-1 VS respectively). During co-digestion of grass silage and cow manure at a ratio of 30:70 (VS) in CSTR, re-circulation of alkali treated solid fraction of digestate did not improve the anaerobic biodegradation rates or methane yields. Results from batch experiments showed that methane potential of grass silage varied from 0.28-0.39 m3 CH{sub 4} kg-1 VS{sub added} in all the experiments. On the other hand, methane potentials of the studied crop residues were 0.32 m3 CH{sub 4} kg-1 VS{sub added} for tomato and 0.26 m3 CH{sub 4} kg-1 VS{sub added} for cucumber and common reed. Alkali pretreatment of solids, obtained from digestate (during co-digestion of grass silage and cow manure in one-stage CSTRs), at a low concentration of 20 g NaOH kg-1 VS resulted in higher methane yield (0.34 m3 CH{sub 4} kg-1 VS{sub added}) than the other tested dosages (40 and 60 g NaOH kg-1 VS). Addition of macro nutrient (NH{sub 4}Cl) enhanced methane potential of

  15. Tillage and residue management effect on soil properties, crop performance and energy relations in greengram (Vigna radiata L. under maize-based cropping systems

    Directory of Open Access Journals (Sweden)

    J.R. Meena

    2015-12-01

    Full Text Available Effect of tillage and crop residue management on soil properties, crop performance, energy relations and economics in greengram (Vigna radiata L. was evaluated under four maize-based cropping systems in an Inceptisol of Delhi, India. Soil bulk density, hydraulic conductivity and aggregation at 0–15 cm layer were significantly affected both by tillage and cropping systems, while zero tillage significantly increased the soil organic carbon content. Yields of greengram were significantly higher in maize–chickpea and maize–mustard systems, more so with residue addition. When no residue was added, conventional tillage required 20% higher energy inputs than the zero tillage, while the residue addition increased the energy output in both tillage practices. Maize–wheat–greengram cropping system involved the maximum energy requirement and the cost of production. However, the largest net return was obtained from the maize–chickpea–greengram system under the conventional tillage with residue incorporation. Although zero tillage resulted in better aggregation, C content and N availability in soil, and reduced the energy inputs, cultivation of summer greengram appeared to be profitable under conventional tillage system with residue incorporation.

  16. Autumn Maize Intercropped with Tropical Forages: Crop Residues, Nutrient Cycling, Subsequent Soybean and Soil Quality

    Directory of Open Access Journals (Sweden)

    Francisco Cézar Belchor Lages Pereira

    2016-01-01

    Full Text Available ABSTRACT Autumn maize intercropped with tropical forages can raise the amount of crop residues and improve nutrient cycling, favoring subsequent soybean crop. The objective of this study was to evaluate the effect of forms of implementation of intercropping of irrigated autumn maize with tropical forages on yield, decomposition, nutrient accumulation and release, and on the ratio of lignin/total N of forage residues, yield components, and grain yield of subsequent soybean, and on soil physical and chemical properties, under no-tillage in lowland Cerrado. The experiment was arranged in randomized blocks in a factorial (4 × 3 + 1 design with one control and four replications. The treatments consisted of four forages: Palisade grass, Congo grass, and two Guinea grass cultivars (Tanzânia and Áries; and three methods of sowing intercrops of forage-autumn maize: forage sown simultaneously with maize in the sowing furrow, mixed with fertilizer; forage sown by broadcasting on the day of maize sowing; and forage seeds mixed with fertilizer broadcast on maize in growth stage V4; plus a control (maize monoculture. The decomposition and nutrient release rate of the forage residues were evaluated by the litter bag method, 30, 60, 90, and 120 days after desiccation. Sowing the forages in the furrow and by broadcasting raise the total amount of maize residues compared to method V4. Regardless of the forage type and sowing methods, intercropping increases the amount of residues compared to maize monoculture. The forages and sowing methods had no influence on nutrient accumulation in the residues at the time of desiccation and at the lowest lignin/total N ratio in Congo grass residues, and a logarithmic decay was observed. Forage and sowing methods did not influence the macronutrient release rate from crop residues for 120 days after desiccation; the release of N, P, K and Mg is logarithmic and the release of Ca and S exponential. Forage and sowing methods do

  17. Biochemical production of bioenergy from agricultural crops and residue in Iran.

    Science.gov (United States)

    Karimi Alavijeh, Masih; Yaghmaei, Soheila

    2016-06-01

    The present study assessed the potential for biochemical conversion of energy stored in agricultural waste and residue in Iran. The current status of agricultural residue as a source of bioenergy globally and in Iran was investigated. The total number of publications in this field from 2000 to 2014 was about 4294. Iran ranked 21st with approximately 54 published studies. A total of 87 projects have been devised globally to produce second-generation biofuel through biochemical pathways. There are currently no second-generation biorefineries in Iran and agricultural residue has no significant application. The present study determined the amount and types of sustainable agricultural residue and oil-rich crops and their provincial distribution. Wheat, barley, rice, corn, potatoes, alfalfa, sugarcane, sugar beets, apples, grapes, dates, cotton, soybeans, rapeseed, sesame seeds, olives, sunflowers, safflowers, almonds, walnuts and hazelnuts have the greatest potential as agronomic and horticultural crops to produce bioenergy in Iran. A total of 11.33million tonnes (Mt) of agricultural biomass could be collected for production of bioethanol (3.84gigaliters (Gl)), biobutanol (1.07Gl), biogas (3.15billion cubic meters (BCM)), and biohydrogen (0.90BCM). Additionally, about 0.35Gl of biodiesel could be obtained using only 35% of total Iranian oilseed. The potential production capacity of conventional biofuel blends in Iran, environmental and socio-economic impacts including well-to-wheel greenhouse gas (GHG) emissions, and the social cost of carbon dioxide reduction are discussed. The cost of emissions could decrease up to 55.83% by utilizing E85 instead of gasoline. The possible application of gaseous biofuel in Iran to produce valuable chemicals and provide required energy for crop cultivation is also studied. The energy recovered from biogas produced by wheat residue could provide energy input for 115.62 and 393.12 thousand hectares of irrigated and rain-fed wheat

  18. An image segmentation based on a genetic algorithm for determining soil coverage by crop residues.

    Science.gov (United States)

    Ribeiro, Angela; Ranz, Juan; Burgos-Artizzu, Xavier P; Pajares, Gonzalo; del Arco, Maria J Sanchez; Navarrete, Luis

    2011-01-01

    Determination of the soil coverage by crop residues after ploughing is a fundamental element of Conservation Agriculture. This paper presents the application of genetic algorithms employed during the fine tuning of the segmentation process of a digital image with the aim of automatically quantifying the residue coverage. In other words, the objective is to achieve a segmentation that would permit the discrimination of the texture of the residue so that the output of the segmentation process is a binary image in which residue zones are isolated from the rest. The RGB images used come from a sample of images in which sections of terrain were photographed with a conventional camera positioned in zenith orientation atop a tripod. The images were taken outdoors under uncontrolled lighting conditions. Up to 92% similarity was achieved between the images obtained by the segmentation process proposed in this paper and the templates made by an elaborate manual tracing process. In addition to the proposed segmentation procedure and the fine tuning procedure that was developed, a global quantification of the soil coverage by residues for the sampled area was achieved that differed by only 0.85% from the quantification obtained using template images. Moreover, the proposed method does not depend on the type of residue present in the image. The study was conducted at the experimental farm "El Encín" in Alcalá de Henares (Madrid, Spain).

  19. Residual soil nitrate content and profitability of five cropping systems in northwest Iowa

    Science.gov (United States)

    Schuiteman, Matthew A.; Vos, Ronald J.

    2017-01-01

    Many communities in the Midwestern United States obtain their drinking water from shallow alluvial wells that are vulnerable to contamination by NO3-N from the surrounding agricultural landscape. The objective of this research was to assess cropping systems with the potential to produce a reasonable return for farmers while simultaneously reducing the risk of NO3-N movement into these shallow aquifers. From 2009 to 2013 we conducted a field experiment in northwest Iowa in which we evaluated five cropping systems for residual (late fall) soil NO3-N content and profitability. Soil samples were taken annually from the top 30 cm of the soil profile in June and August, and from the top 180 cm in November (late fall). The November samples were divided into 30 cm increments for analysis. Average residual NO3-N content in the top 180 cm of the soil profile following the 2010 to 2013 cropping years was 134 kg ha-1 for continuous maize (Zea mays L.) with a cereal rye (Secale cereale L.) cover crop, 18 kg ha-1 for perennial grass, 60 kg ha-1 for a three year oat (Avena sativa L.)-alfalfa (Medicago sativa L.)-maize rotation, 85 kg ha-1 for a two year oat/red clover (Trifolium pratense L.)-maize rotation, and 90 kg ha-1 for a three year soybean (Glycine max (L.) Merr.)-winter wheat (Triticum aestivum L.)-maize rotation. However, residual NO3-N in the 90 to 180 cm increment of the soil profile was not significantly higher in the oat-alfalfa-maize cropping system than the perennial grass system. For 2010 to 2013, average profit ($ ha-1 yr-1) was 531 for continuous corn, 347 for soybean-winter wheat-maize, 264 for oat-alfalfa-maize, 140 for oat/red clover-maize, and -384 (loss) for perennial grass. Considering both residual soil NO3-N and profitability data, the oat-alfalfa-maize rotation performed the best in this setting. However, given current economic pressures widespread adoption is likely to require changes in public policy. PMID:28248976

  20. Growth of legume and nonlegume catch crops and residual-N effects in spring barley on coarse sand

    DEFF Research Database (Denmark)

    Askegaard, Margrethe; Eriksen, Jørgen

    2007-01-01

    Askegaard, M. and Eriksen, E. 2007. Growth of legume and nonlegume catch crops and residual-N effects in spring barley on coarse sand. J. Plant Nutrition and Soil Science, 170, 733-780.......Askegaard, M. and Eriksen, E. 2007. Growth of legume and nonlegume catch crops and residual-N effects in spring barley on coarse sand. J. Plant Nutrition and Soil Science, 170, 733-780....

  1. Illinois biomass resources: annual crops and residues; canning and food-processing wastes. Preliminary assessment

    Energy Technology Data Exchange (ETDEWEB)

    Antonopoulos, A A

    1980-06-01

    Illinois, a major agricultural and food-processing state, produces vast amounts of renewable plant material having potential for energy production. This biomass, in the form of annual crops, crop residues, and food-processing wastes, can be converted to alternative fuels (such as ethanol) and industrial chemicals (such as furfural, ethylene, and xylene). The present study provides a preliminary assessment of these Illinois biomass resources, including (a) an appraisal of the effects of their use on both agriculture and industry; (b) an analysis of biomass conversion systems; and (c) an environmental and economic evaluation of products that could be generated from biomass. It is estimated that, of the 39 x 10/sup 6/ tons of residues generated in 1978 in Illinois from seven main crops, about 85% was collectible. The thermal energy equivalent of this material is 658 x 10/sup 6/ Btu, or 0.66 quad. And by fermenting 10% of the corn grain grown in Illinois, some 323 million gallons of ethanol could have been produced in 1978. Another 3 million gallons of ethanol could have been produced in the same year from wastes generated by the state's food-processing establishments. Clearly, Illinois can strengthen its economy substantially by the development of industries that produce biomass-derived fuels and chemicals. In addition, a thorough evaluation should be made of the potential for using the state's less-exploitable land for the growing of additional biomass.

  2. Comprehensive analysis of soil nitrogen removal by catch crops based on growth and water use

    Science.gov (United States)

    Yasutake, D.; Kondo, K.; Yamane, S.; Kitano, M.; Mori, M.; Fujiwara, T.

    2016-07-01

    A new methodology for comprehensive analysis of the characteristics of nitrogen (N) removal from greenhouse soil by catch crop was proposed in relation to its growth and water use. The N removal is expressed as the product of five parameters: net assimilation rate, specific leaf area, shoot dry weight, water use efficiency for N removal, and water requirement for growth. This methodology was applied to the data of a greenhouse experiment where corn was cultivated under three plant densities. We analyzed the effect of plant density and examined the effectiveness of the methodology. Higher plant densities are advantageous not only for total N removal but also for water use efficiency in N removal and growth because of the large specific leaf area, shoot dry weight, and decreased soil evaporation. On the other hand, significant positive or negative linear relationships were found between all five parameters and N removal. This should improve the understanding of the N removal mechanisms and the interactions among its components. We show the effectiveness of our analytical methodology, which can contribute to identifying the optimum plant density according to the field situations (available water amount, soil N quantity to be removed) for practical catch crop cultivation.

  3. Rethinking Bioenergy from an Agricultural Perspective: Ethical Issues Raised by Perennial Energy Crop and Crop Residue Production in the UK and Denmark

    DEFF Research Database (Denmark)

    Shortall, Orla

    around these controversies is the production of perennial energy crops such as grasses and trees and crop residues such as straw, which are seen to require fewer inputs and less prime land. Some have analysed the controversies raised by biofuels in terms of controversies around industrial agriculture...... that regardless of the type of agricultural system used very little or no biomass should be produced for the energy sector because of the scale of resources it requires and the scale of society’s energy use. These positions can be summarised as three different ways to overcome challenges raised by food crop...

  4. Biodegradation of Fresh vs. Oven-Dried Inedible Crop Residue in a Continuously Stirred Tank Reactor

    Science.gov (United States)

    Crawford, Kamau; Strayer, Richard

    1998-01-01

    The degradation of soluble organics and mineral recovery from fresh and oven-dried biomass were compared in an Intermediate-Scale Aerobic Bioreactor (8 L working volume) to determine if drying crop residue improves performance in a continuously stirred tank reactor (CSTR). The study was conducted in an Intermediate-Scale Aerobic Bioreactor (ISAB) CSTR with dimensions of 390 mm height x 204 mm diameter. The pH in the bioreactor was controlled at 6.0, temperature at 30 C, and aeration at 7.0 L/min. Gases monitored were CO2 evolution and dissolved oxygen. Homogeneously mixed wheat cultures, used either fresh or oven-dried biomass and were leached, then placed in the ISAB for a 4-day degradation period. Studies found that mineral recovery was greater for leached oven-dried crop residue. However, after activity by the mixed microbial communities in the ISAB CSTR, there were little notable differences in the measured mineral recovery and degradation of soluble organic compounds. Degradation of soluble organic compounds was also shown to improve for leached oven-dried crop residue, but after mixing in the CSTR the degradation of the fresh biomass seemed to be slightly greater. Time for the biomass to turn in the CSTR appeared to be one factor for the experimental differences between the fresh and oven-dried biomass. Other factors, although not as defined, were the differing physical structures in the cell walls and varying microbial components of the fresh and oven-dried treatments due to changes in chemical composition after drying of the biomass.

  5. Interaction between soil mineralogy and the application of crop residues on aggregate stability and hydraulic conductivity of the soil

    Science.gov (United States)

    Lado, M.; Kiptoon, R.; Bar-Tal, A.; Wakindiki, I. I. C.; Ben-Hur, M.

    2012-04-01

    One of the main goals of modern agriculture is to achieve sustainability by maintaining crop productivity while avoiding soil degradation. Intensive cultivation could lead to a reduction in soil organic matter that could affect the structure stability and hydraulic conductivity of the soil. Moreover, crops extract nutrients from the soil that are taken away from the field when harvested, and as a consequence, the addition of fertilizers to the soil is necessary to maintain crop productivity. One way to deal with these problems is to incorporate crop residues into the soil after harvest. Crop residues are a source of organic matter that could improve soil physical properties, such as aggregate stability and soil hydraulic conductivity. However, this effect could vary according to other soil properties, such as clay content, clay mineralogy, and the presence of other cementing materials in the soil (mainly carbonates and aluminum and iron oxides). In the present work, the interaction between the addition of chickpea crop residues to the soil and clay mineralogy on aggregate stability and saturated hydraulic conductivity were studied. Chickpea plant residues were added at a rate of 0.5% (w/w) to smectitic, kaolinitic, illitic and non-phyllosilicate soils from different regions. The soils without (control) and with chickpea residues were incubated for 0, 3, 7 and 30 days, and the saturated hydraulic conductivity of the soils was measured in columns after each incubation time. The response of hydraulic conductivity to the addition of residues and incubation time was different in the soils with various mineralogies, although in general, the addition of chickpea residues increased the saturated hydraulic conductivity as compared with the control soils. This positive effect of crop residues on hydraulic conductivity was mainly a result of improved aggregate stability and resistance to slaking during wetting.

  6. Effects of tropical ecosystem engineers on soil quality and crop performance under different tillage and residue management

    Science.gov (United States)

    Pulleman, Mirjam; Paul, Birthe; Fredrick, Ayuke; Hoogmoed, Marianne; Hurisso, Tunsisa; Ndabamenye, Telesphore; Saidou, Koala; Terano, Yusuke; Six, Johan; Vanlauwe, Bernard

    2014-05-01

    Feeding a future global population of 9 billion will require a 70-100% increase in food production, resulting in unprecedented challenges for agriculture and natural resources, especially in Sub-saharan Africa (SSA). Agricultural practices that contribute to sustainable intensification build on beneficial biological interactions and ecosystem services. Termites are the dominant soil ecosystem engineers in arid to sub-humid tropical agro-ecosystems. Various studies have demonstrated the potential benefits of termites for rehabilitation of degraded and crusted soils and plant growth in semi-arid and arid natural ecosystems. However, the contribution of termites to agricultural productivity has hardly been experimentally investigated, and their role in Conservation Agriculture (CA) systems remains especially unclear. Therefore, this study aimed to quantify the effects of termites and ants on soil physical quality and crop productivity under different tillage and residue management systems in the medium term. A randomized block trial was set up in sub-humid Western Kenya in 2003. Treatments included a factorial combination of residue retention and removal (+R/-R) and conventional and reduced tillage (+T/-T) under a maize (Zea mays L.) and soybean (Glyxine max. L.) rotation. A macrofauna exclusion experiment was superimposed in 2005 as a split-plot factor (exclusion +ins; inclusion -ins) by regular applications of pesticides (Dursban and Endosulfan) in half of the plots. Macrofauna abundance and diversity, soil aggregate fractions, soil carbon contents and crop yields were measured between 2005 and 2012 at 0-15 cm and 15-30 cm soil depths. Termites were the most important macrofauna species, constituting between 48-63% of all soil biota, while ants were 13-34%, whereas earthworms were present in very low numbers. Insecticide application was effective in reducing termites (85-56% exclusion efficacy) and earthworms (87%), and less so ants (49-81%) at 0-15 cm soil depth

  7. Variation on the amount of winter cover crops residues on weeds incidence and soil seed bank during an agricultural year

    Directory of Open Access Journals (Sweden)

    Márcia Maria Mauli

    2011-08-01

    Full Text Available This study analyzed possible interferences associated to the amount of crop residues produced by the black oats and the consortium of black oats, common vetch and forage turnip on weeds incidence and soil seed bank. It was a field trial with seven treatments and five replications. The cover crop was sown at throwing, cut at 100 days and residues were put on each respective plot, using a proportion of normal amount of produced straw, either its half and double. The heaviest weights were obtained from cover crop consortium and their application decreased weeds incidence in such area. The seeds bank and other analyzed parameters did not show statistical differences. According to these results, it was concluded that winter cover crop could be used in crops rotation with soybean.

  8. Availability of nitrogen in 15N-labelled mature pea residues to subsequent crops in the field

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1994-01-01

    rape (Brassica napus oleifera L.) recovered about 13% of the pea residue N during the initial 3 months of growth. At maturity the crops had recovered 15 and 13% respectively. This indicates that a major part of the residue N was mineralized and thus available to autumn-sown crops a few months after...... incorporation of the residues. At maturity, the pea residue N constituted fertilizer) N accumulated by crops. The recovery of pea residue N in successive autumn-sown crops of barley....... The concentration of organic N-15 in topsoils showed that 55% to 59% of the organic N-15 had been released during 3 yr of decomposition in soils cropped to autumn- or spring-sown crops respectively. The total crop recovery of N-15 was only 20% for autumn-sown and 9% for spring-sown crops. This indicates...

  9. Degradation and sorption of fipronil and atrazine in Latossols with organic residues from sugarcane crop

    Directory of Open Access Journals (Sweden)

    Raquel de Oliveira Silva

    2016-07-01

    Full Text Available ABSTRACT: Organic residues from sugarcane crop and processing (vinasse, boiler ash, cake filter, and straw are commonly applied or left on the soil to enhance its fertility. However, they can influence pesticide degradation and sorption. The objective of this study was to assess the effect of adding these organic residues on the degradation and sorption of fipronil and atrazine in two soils of the State of Mato Grosso do Sul, MS, Brazil. The degradation experiment was carried out with laboratory-incubated (40 days; 28°C; 70% field capacity soils (0-10cm. The batch equilibration method was used to determine sorption. Fipronil (half-life values of 15-105 days showed to be more persistent than atrazine (7-17 days. Vinasse application to the soil favored fipronil and atrazine degradation, whereas cake filter application decreased the degradation rates for both pesticides. Values for sorption coefficients (Kd were determined for fipronil (5.1-13.2mL g-1 and atrazine (0.5-1.5mL g-1. Only straw and cake filter residues enhanced fipronil sorption when added to the soil, whereas all sugarcane residues increased atrazine sorption.

  10. A Metagenomic Advance for the Cloning and Characterization of a Cellulase from Red Rice Crop Residues.

    Science.gov (United States)

    Meneses, Carlos; Silva, Bruna; Medeiros, Betsy; Serrato, Rodrigo; Johnston-Monje, David

    2016-06-25

    Many naturally-occurring cellulolytic microorganisms are not readily cultivable, demanding a culture-independent approach in order to study their cellulolytic genes. Metagenomics involves the isolation of DNA from environmental sources and can be used to identify enzymes with biotechnological potential from uncultured microbes. In this study, a gene encoding an endoglucanase was cloned from red rice crop residues using a metagenomic strategy. The amino acid identity between this gene and its closest published counterparts is lower than 70%. The endoglucanase was named EglaRR01 and was biochemically characterized. This recombinant protein showed activity on carboxymethylcellulose, indicating that EglaRR01 is an endoactive lytic enzyme. The enzymatic activity was optimal at a pH of 6.8 and at a temperature of 30 °C. Ethanol production from this recombinant enzyme was also analyzed on EglaRR01 crop residues, and resulted in conversion of cellulose from red rice into simple sugars which were further fermented by Saccharomyces cerevisiae to produce ethanol after seven days. Ethanol yield in this study was approximately 8 g/L. The gene found herein shows strong potential for use in ethanol production from cellulosic biomass (second generation ethanol).

  11. A Metagenomic Advance for the Cloning and Characterization of a Cellulase from Red Rice Crop Residues

    Directory of Open Access Journals (Sweden)

    Carlos Meneses

    2016-06-01

    Full Text Available Many naturally-occurring cellulolytic microorganisms are not readily cultivable, demanding a culture-independent approach in order to study their cellulolytic genes. Metagenomics involves the isolation of DNA from environmental sources and can be used to identify enzymes with biotechnological potential from uncultured microbes. In this study, a gene encoding an endoglucanase was cloned from red rice crop residues using a metagenomic strategy. The amino acid identity between this gene and its closest published counterparts is lower than 70%. The endoglucanase was named EglaRR01 and was biochemically characterized. This recombinant protein showed activity on carboxymethylcellulose, indicating that EglaRR01 is an endoactive lytic enzyme. The enzymatic activity was optimal at a pH of 6.8 and at a temperature of 30 °C. Ethanol production from this recombinant enzyme was also analyzed on EglaRR01 crop residues, and resulted in conversion of cellulose from red rice into simple sugars which were further fermented by Saccharomyces cerevisiae to produce ethanol after seven days. Ethanol yield in this study was approximately 8 g/L. The gene found herein shows strong potential for use in ethanol production from cellulosic biomass (second generation ethanol.

  12. Composting of cow dung and crop residues using termite mounds as bulking agent.

    Science.gov (United States)

    Karak, Tanmoy; Sonar, Indira; Paul, Ranjit K; Das, Sampa; Boruah, R K; Dutta, Amrit K; Das, Dilip K

    2014-10-01

    The present study reports the suitability of termite mounds as a bulking agent for composting with crop residues and cow dung in pit method. Use of 50 kg termite mound with the crop residues (stover of ground nut: 361.65 kg; soybean: 354.59 kg; potato: 357.67 kg and mustard: 373.19 kg) and cow dung (84.90 kg) formed a good quality compost within 70 days of composting having nitrogen, phosphorus and potassium as 20.19, 3.78 and 32.77 g kg(-1) respectively with a bulk density of 0.85 g cm(-3). Other physico-chemical and germination parameters of the compost were within Indian standard, which had been confirmed by the application of multivariate analysis of variance and multivariate contrast analysis. Principal component analysis was applied in order to gain insight into the characteristic variables. Four composting treatments formed two different groups when hierarchical cluster analysis was applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Anaerobic Biodegradability and Methane Potential of Crop Residue Co-Digested with Buffalo Dung

    Directory of Open Access Journals (Sweden)

    Abdul Razaque Sahito

    2013-07-01

    Full Text Available ABD (Anaerobic Biodegradability and BMP (Biochemical Methane Potential of banana plant waste, canola straw, cotton stalks, rice straw, sugarcane trash and wheat straw co-digested with buffalo dung was evaluated through AMPTS (Automatic Methane Potential Test System. The substrates were analyzed for moisture, TS (Total Solids and VS (Volatile Solids, ultimate analysis (CHONS, pH and TA (Total Alkalinity. The BMPobserved during incubation of 30 days at the temperature of 37±0.2°C was 322 Nml CH4/g VSadd for wheat straw followed by 260, 170, 149, 142 and 138 Nml CH4/gVSadd for canola straw, rice straw, cotton stalks, banana plant waste and sugarcane trash respectively, whereas the maximum theoretical BMP was 481 Nml CH4/gVSadd for cotton stalks, followed by 473, 473, 446, 432 and 385 Nml CH4/gVSadd for wheat straw, banana plant waste, canola straw, rice straw and sugarcane trash respectively. The percentage ABD values were in the range of 68-30%. In addition to this, the effect of lignin content in the crop residue was evaluated on the ABD. The results of this study indicate that, the co-digestion of the crop residues with buffalo dung is feasible for production of renewable methane

  14. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Science.gov (United States)

    Hai-Ming, Tang; Xiao-Ping, Xiao; Wen-Guang, Tang; Ye-Chun, Lin; Ke, Wang; Guang-Li, Yang

    2014-01-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L.) (R-R-Ry), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice-rice-rape (Brassica napus L.) (R-R-Ra) and rice-rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (Pwinter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  15. Residual phytotoxicity of parthenium: Impact on some winter crops, weeds and soil properties.

    Science.gov (United States)

    Khaliq, Abdul; Aslam, Farhena; Matloob, Amar; Hussain, Saddam; Tanveer, Asif; Alsaadawi, Ibrahim; Geng, Mingjian

    2015-12-01

    Phytotoxic effects of parthenium residues incorporation and parthenium-infested rhizospheric soil on emergence and seedling growth of winter crops (wheat and canola) and weed species (wild oat and canary grass) were examined in different pot studies. In first experiment, parthenium whole plant residues were incorporated at 6 and 8 g kg(-1) soil five days prior to sowing. Pots without residues incorporation were maintained as control. In a second study, parthenium-infested rhizospheric soil collected from different depths (15 and 22.5 cm) and collar regions (horizontal distance away from plant trunk, 15 and 22.5 cm), was used as growing medium. Parthenium-free soil was used as control. Parthenium residues amendment as well as its rhizospheric soil was detrimental for emergence and seedling growth of all test species. Incorporation of parthenium residues reduced the final emergence of canola, wild oat and canary grass by 11-20%, 20-29% and 20-27%, respectively; however wheat emergence was unaffected. Moreover, seedling biomass of wheat, canola, wild oat and canary grass was reduced in the range of 41-48%, 53-61%, 31-45% and 30-45% by parthenium residues incorporation. In second study, soil collected from a rhizospheric depth of 15 cm and collar distance of 15 cm reduced the emergence and seedling growth by 15% and 40%, respectively averaged across different test species. Parthenium residues incorporation and infested rhizospheric soil increased the soil phenolics, electrical conductivity, organic carbon and nitrogen contents over control soils with the exception of pH that was declined. All test species manifested reduced chlorophyll and increased phenolic contents in response to parthenium residues incorporation and infested rhizospheric soil. The inhibition in emergence and seedling growth of all test species was associated with increase in phenolic contents. Parthenium residues incorporation at 8 g kg(-1) soil and upper parthenium-infested rhizospheric soil (15 cm

  16. AVAILABILITY AND PHYSICAL PROPERTIES OF RESIDUES FROM MAJOR AGRICULTURAL CROPS FOR ENERGY CONVERSION THROUGH THERMOCHEMICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    Yaning Zhang

    2012-01-01

    Full Text Available Plant residues from the major agricultural crops (wheat, rice, corn, soybean, sugarcane, coffee and cotton are abundantly available renewable resources that can be used to supply energy through thermochemical conversion processes. The available amounts of plant residues from these crops and their physical properties (moisture content, particle size, bulk density and porosity were determined. The annual residues from the wheat, rice, corn, soybean, sugarcane, coffee and cotton were 763.42, 698.10, 1729.92, 416.62, 16.85, 4.01 and 107.13 million tons, respectively. The total amount of plant residues was estimated at 3736.05 million tons with total energy content of 66.92 EJ. These residues can replace 2283.52 million tons of coal, 1551.78 million tons of oil and 1847.63 million m3 of natural gas. The moisture contents were 7.79, 6.58, 6.40, 7.30, 8.15, 7.86 and 7.45% for the wheat straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk, respectively. The corn stalk and sugarcane stalk had a convex particle size distribution, the soybean stalk and cotton stalk had a concave particle size distribution, the wheat straw and rice straw had an increasing trend particle size distribution and the coffee husk had a decreasing trend particle size distribution. The average particle sizes for the wheat straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk were 0.42, 0.40, 0.49, 0.43, 0.55, 0.67 and 0.38 mm, respectively. The average bulk density was 160.75, 166.29, 127.32, 242.34, 110.86, 349.06 and 230.55 kg m-3 for the wheat straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk, respectively. The average porosity was 51.25, 83.20, 58.51, 68.03, 77.58, 64.85 and 74.55% for the wheat straw, rice straw, corn stalk, soybean stalk, sugarcane stalk, coffee husk and cotton stalk, respectively. The results obtained from this study indicate that different

  17. Long-term C-CO2 emissions and carbon crop residue mineralization in an oxisol under different tillage and crop rotation systems

    Directory of Open Access Journals (Sweden)

    Ben-Hur Costa de Campos

    2011-06-01

    Full Text Available Soil C-CO2 emissions are sensitive indicators of management system impacts on soil organic matter (SOM. The main soil C-CO2 sources at the soil-plant interface are the decomposition of crop residues, SOM turnover, and respiration of roots and soil biota. The objectives of this study were to evaluate the impacts of tillage and cropping systems on long-term soil C-CO2 emissions and their relationship with carbon (C mineralization of crop residues. A long-term experiment was conducted in a Red Oxisol in Cruz Alta, RS, Brazil, with subtropical climate Cfa (Köppen classification, mean annual precipitation of 1,774 mm and mean annual temperature of 19.2 ºC. Treatments consisted of two tillage systems: (a conventional tillage (CT and (b no tillage (NT in combination with three cropping systems: (a R0- monoculture system (soybean/wheat, (b R1- winter crop rotation (soybean/wheat/soybean/black oat, and (c R2- intensive crop rotation (soybean/ black oat/soybean/black oat + common vetch/maize/oilseed radish/wheat. The soil C-CO2 efflux was measured every 14 days for two years (48 measurements, by trapping the CO2 in an alkaline solution. The soil gravimetric moisture in the 0-0.05 m layer was determined concomitantly with the C-CO2 efflux measurements. The crop residue C mineralization was evaluated with the mesh-bag method, with sampling 14, 28, 56, 84, 112, and 140 days after the beginning of the evaluation period for C measurements. Four C conservation indexes were used to assess the relation between C-CO2 efflux and soil C stock and its compartments. The crop residue C mineralization fit an exponential model in time. For black oat, wheat and maize residues, C mineralization was higher in CT than NT, while for soybean it was similar. Soil moisture was higher in NT than CT, mainly in the second year of evaluation. There was no difference in tillage systems for annual average C-CO2 emissions, but in some individual evaluations, differences between

  18. Responses of Pea (Pisum sativum Growth and Yield to Residual Effects of Organic and Urea Fertilizers from Previous Crop

    Directory of Open Access Journals (Sweden)

    S. Fallah

    2016-07-01

    Full Text Available Application of organic manure in organic farming and long-term mineralization may lead to residual effects on the succeeding crop. So, residual effects of combined cattle manure and urea fertilizer of previous crop (black cumin on growth and yield of pea were examined in a randomized complete block design. Treatments included of  cattle manure (CM, urea (U, three ratios of CM+U full dose application (2:1; 1:1; 1:2 and three ratios of CM+U split application (2:1; 1:1; 1:2, and unfertilized control to previous crop (black cumin in 2012. Pea planted without any fertilizer in 2013. There was no significant difference between control and residual of urea treatment for some parameters including dry matter in flowering stage, plant nitrogen and phosphorus concentration, plant height, yield components, grain yield and biological yield of pea. Biological and grain yields were greater under both residual of cattle manure treatment and integrated treatments compared to residual of urea treatment. The highest grain yield (4000 kg ha-1 was observed in residual of CM:U full dosed application treatment, to the extent that grain yield in this treatment indicated a 1.5-fold increase in comparison with residual of urea treatment. The highest biological yield (8325 kg ha-1 was obtained in residual of CM treatment, though it was not significant different from that of residual of CM:U (1:2 treatments. In general, although residual of urea fertilizer did not leave a notable effect on pea production, but production of this crop relying on residual of cattle manure deems effective to lowering of fertilization cost and ameliorating environmental contaminations.

  19. Phosphate Removal and Recovery using Drinking Water Plant Waste Residuals

    Science.gov (United States)

    Water treatment plants are used to provide safe drinking water. In parallel, however, they also produce a wide variety of waste products which, in principle, could be possible candidates as resources for different applications. Calcium carbonate is one of such residual waste in ...

  20. Phosphate Removal and Recovery using Drinking Water Plant Waste Residuals

    Science.gov (United States)

    Water treatment plants are used to provide safe drinking water. In parallel, however, they also produce a wide variety of waste products which, in principle, could be possible candidates as resources for different applications. Calcium carbonate is one of such residual waste in ...

  1. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    OpenAIRE

    2009-01-01

    A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS), which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (S...

  2. Dissipation of diethyl aminoethyl hexanoate (DA-6) residues in pakchoi, cotton crops and soil.

    Science.gov (United States)

    Jiang, Yaping; Jiang, Yuting; He, Shun; Zhang, Heli; Pan, Canping

    2012-04-01

    QuEChERS procedure and acetonitrile extraction, oscillation and ultrasonic procedure followed by GC-MS and LC-MS/MS (QqQ) detections were established for determination of diethyl aminoethyl hexanoate (DA-6) residues in pakchoi, cotton leaf, cotton seed and soil. At concentration levels of 0.005-1 mg kg(-1), recoveries were in the range of 80.5%-103.3%, with a RSD less than 14.2%. The LOQs of methods were 0.005, 0.003, 0.005 and 0.001 mg kg(-1) for the pakchoi, cotton leaf, soil and cotton seed samples, respectively. DA-6 was applied in supervised field trials at GAP conditions to pakchoi and cotton. It was found that the dissipation half-lives of DA-6 were 5.4-8.2 days and 1.1-2.2 days and 1.5-1.9 days in cotton crop, pakchoi and soil respectively. At harvest, no detectable residues (cotton samples. However, residues was detected in pakchoi (0.007-0.013 mg/kg) in Beijing and soil (0.008-0.014 mg/kg) in Changsha in 2008.

  3. Removal of metal ions from contaminated water using agricultural residues

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    As the world population grows, there is a growing awareness that our environment is getting more polluted. Clean water is becoming a critical issue for many parts of the world for human, animal and agricultural use. Filtration systems to clean our air and water are a growing industry. There are many approaches to removing contaminates from our water supply ranging from...

  4. Size distributions of aerosol and water-soluble ions in Nanjing during a crop residual burning event

    Institute of Scientific and Technical Information of China (English)

    Honglei Wang; Bin Zhu; Lijuan Shen; Hanqing Kang

    2012-01-01

    To investigate the impact on urban air pollution by crop residual burning outside Nanjing,aerosol concentration,pollution gas concentration,mass concentration,and water-soluble ion size distribution were observed during one event of November 4-9,2010.Results show that the size distribution of aerosol concentration is bimodal on pollution days and normal days,with peak values at 60-70 and 200-300 nm,respectively.Aerosol concentration is 104 cm-3.nm-1 on pollution days.The peak value of spectrum distribution of aerosol concentration on pollution days is 1.5-3.3 times higher than that on a normal day.Crop residual burning has a great impact on the concentration of fine particles.Diurnal variation of aerosol concentration is trimodal on pollution days and normal days,with peak values at 03:00,09:00 and 19:00 local standard time.The first peak is impacted by meteorological elements,while the second and third peaks are due to human activities,such as rush hour traffic.Crop residual burning has the greatest impact on SO2 concentration,followed by NO2,O3 is hardly affected.The impact of crop residual burning on fine particles(< 2.1 μm) is larger than on coarse particles(> 2.1 μm),thus ion concentration in fine particles is higher than that in coarse particles.Crop residual burning leads to similar increase in all ion components,thus it has a small impact on the water-soluble ions order.Crop residual burning has a strong impact on the size distribution of K+,Cl-,Na+,and F- and has a weak impact on the size distributions of NH4+,Ca2+,NO3- and SO42-.

  5. Environmental performance of crop residues as an energy source for electricity production

    DEFF Research Database (Denmark)

    Nguyen, T Lan T; Hermansen, John Erik; Mogensen, Lisbeth

    2013-01-01

    or for natural gas reduces global warming, non-renewable energy use, human toxicity and ecotoxicity, but increases eutrophication, respiratory inorganics, acidification and photochemical ozone. The results at the aggregate level show that the use of straw biomass for conversion to energy scores better than...... that of coal but worse than natural gas. In order to investigate the question of whether and how a reduction in the single score per kW h of electricity produced from straw is feasible, we perform a scenario analysis where we consider two approaches. The first one is a potential significant reduction......This paper aims to address the question, “What is the environmental performance of crop residues as an alternative energy source to fossil fuels, and whether and how can it be improved?”. In order to address the issue, we compare electricity production from wheat straw to that from coal and natural...

  6. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study.

    Science.gov (United States)

    Cassigneul, A; Benoit, P; Bergheaud, V; Dumeny, V; Etiévant, V; Goubard, Y; Maylin, A; Justes, E; Alletto, L

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of (14)C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. (14)C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH4OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends (14)C-glyphosate degradation half-life from 7 to 28 days depending on the CC. (14)C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity.

  7. Efficiency and emission of crop residues combustion facilities in Serbia: Status and needed measures for improvement

    Directory of Open Access Journals (Sweden)

    Martinov Milan

    2006-01-01

    Full Text Available Use of crop residues as fuel has a long tradition in rural areas of Serbia. Numerous biomass-fueled facilities were built during the 80s. Among those were small facilities for household heating, with thermal power from 5 to 50 kW, medium-size facilities for farm and greenhouses, with thermal power 50 to 1000 kW, and large facilities for processing of agricultural products, with thermal powers higher than 1000 kW. The results showed that the level of biomass combustion facilities is in general very low. This is especially the case for heating facilities used for house-hold heating. The measures for improvement were proposed. .

  8. Metal Availability following Paper Mill and Alkaline Residuals Application to Field Crops.

    Science.gov (United States)

    Gagnon, Bernard; Ziadi, Noura; Robichaud, Annie; Karam, Antoine

    2013-01-01

    Land application of residuals from the forest industry can help to restore soil fertility, but few studies have assessed the effects of metal accumulation in plants. An experimental study was initiated in 2000 on a loamy soil at Yamachiche, QC, Canada, to evaluate the effects of repeated annual applications of combined paper mill biosolids, when applied alone or with several liming by-products. This study assessed the accumulation of Cu, Zn, Mo, and Cd in plants and soil after 6 (soybean [ (L.) Merr.]) and 9 [corn ( L.)] crop yr. Wet paper mill biosolids at 0, 30, 60, or 90 Mg ha were surface applied after seeding. Calcitic lime, lime mud, and wood ash were applied wet each at 3 Mg ha with 30 Mg wet paper mill biosolids ha. Repeated applications of paper mill biosolids increased plant and soil metal concentrations after 6 and 9 yr in the order of Cd > Mo (soybean) > Zn > Cu. Liming increased soil pH and Mo availability and decreased Zn and Cd availability. Metals in crop stover responded more positively to applications than those in grains, but the concentrations in plant tissues were generally well below critical values. The Cu/Mo ratio of soybean plants at pH > 6.8 fell below 2:1, however, and may pose a risk for inducing Cu metabolism disorder in ruminants. Results of this study indicate that paper mill biosolids and alkaline residuals, when applied with respect to regulations and soil pH, have a limited effect on metal accumulation in plants and soil.

  9. EnviroAtlas - Crop phosphorus removal by 12-digit HUC for 2012 for the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas national map displays the mean crop phosphorus (P) removal from croplands in the conterminous United States (excluding Hawaii and Alaska) for the...

  10. Blast furnace residues for arsenic removal from mining-contaminated groundwater.

    Science.gov (United States)

    Carrillo-Pedroza, Fco Raúl; Soria-Aguilar, Ma de Jesús; Martínez-Luevanos, Antonia; Narvaez-García, Víctor

    2014-01-01

    In this work, blast furnace (BF) residues were well characterized and then evaluated as an adsorbent material for arsenic removal from a mining-contaminated groundwater. The adsorption process was analysed using the theories of Freundlich and Langmuir. BF residues were found to be an effective sorbent for As (V) ions. The modelling of adsorption isotherms by empirical models shows that arsenate adsorption is fitted by the Langmuir model, suggesting a monolayer adsorption of arsenic onto adsorbents. Arsenate adsorption onto BF residue is explained by the charge density surface affinity and by the formation of Fe (II) and Fe (III) corrosion products onto BF residue particles. The results indicate that BF residues represent an attractive low-cost absorbent option for the removal of arsenic in wastewater treatment.

  11. Direct radiative effect of carbonaceous aerosols from crop residue burning during the summer harvest season in East China

    Science.gov (United States)

    Yao, Huan; Song, Yu; Liu, Mingxu; Archer-Nicholls, Scott; Lowe, Douglas; McFiggans, Gordon; Xu, Tingting; Du, Pin; Li, Jianfeng; Wu, Yusheng; Hu, Min; Zhao, Chun; Zhu, Tong

    2017-04-01

    East China experiences extensive crop residue burnings in fields during harvest season. The direct radiative effect (DRE) of carbonaceous aerosols from crop residue burning in June 2013 in East China was investigated using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). Absorption of organic aerosol (OA) in the presence of brown carbon was considered using the parameterization of Saleh et al. (2014), in which the imaginary part of the OA refractive index is a function of wavelength and the ratio of black carbon (BC) and OA. The carbonaceous emissions from crop fires were estimated using the Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power (FRP) product with a localized crop-burning-sourced BC-to-organic carbon (OC) ratio emission ratio of 0.27. Evaluation of the model results with in situ measurements of particulate matter with aerodynamic diameter less than 2.5 µm (PM2. 5) chemical composition, MODIS aerosol optical depth (AOD) detections and meteorological observations showed that this model was able to reproduce the magnitude, spatial variation and optical characteristics of carbonaceous aerosol pollution. The observed BC and OC peak concentrations at the site in Suixi, Anhui province, during the 2013 wheat burning season reached 55.3 µg m-3 and 157.9 µg m-3. WRF-Chem simulations reproduced these trends with a correlation coefficient of 0.74, estimating that crop residue burning contributed 86 and 90 % of peak BC and OC, respectively. The simulated hourly DRE from crop residue burning at the top of atmosphere (TOA) reached a maximum of +22.66 W m-2 at the Suixi site. On average, the simulations showed that the crop residue burning introduced a net positive DRE of +0.14 W m-2 at TOA throughout East China, with BC from this source as the main heating contributor (+0.79 W m-2). The OA DRE from crop burning (-0.22 W m-2) was a combined effect of the positive DRE of absorption (+0.21 W m-2) and a stronger

  12. Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies

    OpenAIRE

    Belén Martínez-Alcántara; Mary-Rus Martínez-Cuenca; Carlos Fernández; Francisco Legaz; Ana Quiñones

    2016-01-01

    Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labe...

  13. Development of the crop residue and rangeland burning in the 2014 National Emissions Inventory using information from multiple sources.

    Science.gov (United States)

    Pouliot, George; Rao, Venkatesh; McCarty, Jessica L; Soja, Amber

    2017-05-01

    Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. One component of the biomass burning inventory, crop residue burning, has been poorly characterized in the National Emissions Inventory (NEI). In the 2011 NEI, wildland fires, prescribed fires, and crop residue burning collectively were the largest source of PM2.5. This paper summarizes our 2014 NEI method to estimate crop residue burning emissions and grass/pasture burning emissions using remote sensing data and field information and literature-based, crop-specific emission factors. We focus on both the postharvest and pre-harvest burning that takes place with bluegrass, corn, cotton, rice, soybeans, sugarcane and wheat. Estimates for 2014 indicate that over the continental United States (CONUS), crop residue burning excluding all areas identified as Pasture/Grass, Grassland Herbaceous, and Pasture/Hay occurred over approximately 1.5 million acres of land and produced 19,600 short tons of PM2.5. For areas identified as Pasture/Grass, Grassland Herbaceous, and Pasture/Hay, biomass burning emissions occurred over approximately 1.6 million acres of land and produced 30,000 short tons of PM2.5. This estimate compares with the 2011 NEI and 2008 NEI as follows: 2008: 49,650 short tons and 2011: 141,180 short tons. Note that in the previous two NEIs rangeland burning was not well defined and so the comparison is not exact. The remote sensing data also provided verification of our existing diurnal profile for crop residue burning emissions used in chemical transport modeling. In addition, the entire database used to estimate this sector of emissions is available on EPA's Clearinghouse for Inventories and Emission Factors (CHIEF, http://www3.epa.gov/ttn/chief/index.html ).

  14. Oil crop biomass residue-based media for enhanced algal lipid production.

    Science.gov (United States)

    Wang, Zhen; Ma, Xiaochen; Zhou, Wenguang; Min, Min; Cheng, Yanling; Chen, Paul; Shi, Jian; Wang, Qin; Liu, Yuhuan; Ruan, Roger

    2013-10-01

    The aim of this study was to evaluate the use of hydrolysates from acid hydrolysis of four different oil crop biomass residues (OCBR) as low cost culture media for algae growth. The one-factor-at-a-time method was used to design a series of experiments to optimize the acid hydrolysis conditions through examining the total nitrogen, total phosphorus, chemical oxygen demand, and ammonia nitrogen in the hydrolysates. The optimal conditions were found to be using 3% sulfuric acid and hydrolyzing residues at 90 °C for 20 h. The hydrolysates (OCBR media) produced under the optimal conditions were used to cultivate the two algae strains, namely UM258 and UM268. The results from 5 days of cultivation showed that the OCBR media supported faster algae growth with maximal algal biomass yield of 2.7 and 3 g/L, respectively. Moreover, the total lipids for UM258 and UM268 were 54 and 35%, respectively, after 5 days of cultivation, which suggested that the OCBR media allowed the algae strains to accumulate higher lipids probably due to high C/N ratio. Furthermore, over 3% of omega-3 fatty acid (EPA) was produced for the two algae strains. In conclusion, OCBR media are excellent alternative for algae growth and have a great potential for large-scale production of algae-based ingredients for biodiesel as well as high-value food and pharmaceutical products.

  15. Integrating biological treatment of crop residue into a hydroponic sweetpotato culture.

    Science.gov (United States)

    Trotman, A A; David, P P; Bonsi, C K; Hill, W A; Mortley, D G; Loretan, P A

    1997-01-01

    Residual biomass from hydroponic culture of sweetpotato [Ipomoea batatas (L.) Lam.] was degraded using natural bacterial soil isolates. Sweetpotato was grown for 120 days in hydroponic culture with a nutrient solution comprised of a ratio of 80% modified half Hoagland solution to 20% filtered effluent from an aerobic starch hydrolysis bioreactor. The phytotoxicity of the effluent was assayed with Waldmann's Green' lettuce (Lactuca sativa L.) and the ratio selected after a 60-day bioassay using sweetpotato plants propagated vegetatively from cuttings. Controlled environment chamber experiments were conducted to investigate the impact of filtrate from biological treatment of crop residue on growth and storage root production with plants grown in a modified half Hoagland solution. Incorporation of bioreactor effluent, reduced storage root yield of 'Georgia Jet' sweetpotato but the decrease was not statistically significant when compared with yield for plants cultured in a modified half Hoagland solution without filtrate. However, yield of 'TU-82-155' sweetpotato was significantly reduced when grown in a modified half Hoagland solution into which filtered effluent had been incorporated. Total biomass was significantly reduced for both sweetpotato cultivars when grown in bioreactor effluent. The leaf area and dry matter accumulation were significantly (P < 0.05) reduced for both cultivars when grown in solution culture containing 20% filtered effluent.

  16. Integrating biological treatment of crop residue into a hydroponic sweetpotato culture

    Science.gov (United States)

    Trotman, A. A.; David, P. P.; Bonsi, C. K.; Hill, W. A.; Mortley, D. G.; Loretan, P. A.

    1997-01-01

    Residual biomass from hydroponic culture of sweetpotato [Ipomoea batatas (L.) Lam.] was degraded using natural bacterial soil isolates. Sweetpotato was grown for 120 days in hydroponic culture with a nutrient solution comprised of a ratio of 80% modified half Hoagland solution to 20% filtered effluent from an aerobic starch hydrolysis bioreactor. The phytotoxicity of the effluent was assayed with `Waldmann's Green' lettuce (Lactuca sativa L.) and the ratio selected after a 60-day bioassay using sweetpotato plants propagated vegetatively from cuttings. Controlled environment chamber experiments were conducted to investigate the impact of filtrate from biological treatment of crop residue on growth and storage root production with plants grown in a modified half Hoagland solution. Incorporation of bioreactor effluent, reduced storage root yield of `Georgia Jet' sweetpotato but the decrease was not statistically significant when compared with yield for plants cultured in a modified half Hoagland solution without filtrate. However, yield of `TU-82-155' sweetpotato was significantly reduced when grown in a modified half Hoagland solution into which filtered effluent had been incorporated. Total biomass was significantly reduced for both sweetpotato cultivars when grown in bioreactor effluent. The leaf area and dry matter accumulation were significantly (P < 0.05) reduced for both cultivars when grown in solution culture containing 20% filtered effluent.

  17. Fermentation quality and nutritive value of rice crop residue based silage ensiled with addition of epiphytic lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    B Santoso

    2011-03-01

    Full Text Available Silage is the feedstuff resulted from the preservation of forages through lactic acid fermentation. The aim of this study was to evaluate nutritive value, fermentation characteristics and nutrients digestibility of rice crop residue based silage ensiled with epiphytic lactic acid bacteria (LAB. The mixture of rice crop residue (RC, soybean curd residue (SC and cassava waste (CW in a 90: 5: 5 (on dry matter basis ratio was used as silage material. Three treatments silage were (A RC + SC + CW as a control; (B RC + SC + CW + LAB inoculums from rice crop residue; (C RC + SC + CW + LAB inoculums from king grass. Silage materials were packed into plastic silo (1.5 kg capacity and stored for 30 days. The results showed that crude protein content in B and C silage was higher than that of silage A, but NDF content in silages B and C was lower than that of silage A. Lactic acid concentration was higher (P < 0.01 in silage C compared to silage B and A, thus pH value of silage C was lower (P < 0.01 than silage B and A. Silage C had the highest Fleigh point than that of other silages. Dry matter and organic matter digestibilities were higher in silages B and C (P < 0.01 than that of control silage. It was concluded that the addition of LAB inoculums from king grass to rice crop residue based silage resulted a better fermentation quality compared to LAB inoculums from rice crop residue.

  18. Investigation of Sensitivity of Some Pulses and Agronomic Crops to Soil Residue of Idosulfuron-mesosulfurun Herbicide

    Directory of Open Access Journals (Sweden)

    E. Izadi-Darbandi

    2013-03-01

    Full Text Available To study the sensitivity of chick pea, bean, lentil, rapeseed, sugarbeet and tomato to soil residual concentration of Idosulfuron-mesosulfurun herbicide, an experiment was carried out under controlled conditions at the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2010. The studied factors were the 6 mentioned crops, and 7 levels of soil residual concentration of Idosulfuron-mesosulfurun herbicide (0, 0.0015, 0.0037, 0.0079, 0.015, 0.031 and 0.047 mg per kg of soil. The factorial experiment was carried out as a completely randomized design with three replications. Crops' emergence percentage was determined one week after their emergence. Plants' survival percentage and shoot and root biomass production were measured 30 days after their emergence. Results showed that all mentioned characteristics decreased significantly (P<0.01 in the presence of soil residue of the herbicide. Increasing Idosulfuron-mesosulfurun residual concentration in soil decreased emergence and shoot and root biomass production. Bean had the lowest shoot (44% and root (66.78% biomass loss and tomato had the highest shoot (96.38% and root (89.64% biomass loss. Based on ED50 index, pea (0.0079 mg/kg soil was the most tolerant and tomato (0.0003 mg/kg soil was the most susceptible crop to soil residues of Idosulfuron-mesosulfurun, and other crops ranked in between as: tomato< sugarbeet< rapeseed< lentil< bean< pea. In general, these results showed that soil residue of Idosulfuron-mesosulfurun can injure rotation crops and it is important to consider their sensitivity in rotation programming.

  19. Nitrous oxide and N-leaching losses from agricultural soil: Influence of crop residue particle size, quality and placement

    DEFF Research Database (Denmark)

    Ambus, P.; Jensen, E.S.; Robertson, G.P.

    2001-01-01

    protection of the crop residue material against microbial attack. Leaching of N tended to be reduced about 40 % with barley and 20 % with pea, but the numbers were not significantly different from residue-free soil, which leached 4.7-4.9 g N m(-2). When wheat and alfalfa residues were mixed into the soil N2O...... emissions increased 6.5 and 1.6 times, respectively, compared with residue placed in a layer. Wheat residue in a layer evolved 3.4-times less N2O than alfalfa in a layer, whereas when mixed the two residue types evolved similar amounts of N2O. This difference was probably due to N-limitations in localised...

  20. How does adding and removing liquid from socket bladders affect residual-limb fluid volume?

    Directory of Open Access Journals (Sweden)

    Joan E. Sanders, PhD

    2013-08-01

    Full Text Available Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/– 8.4 mL (mean +/– standard deviation, corresponding with 1.7% +/– 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.

  1. How does adding and removing liquid from socket bladders affect residual-limb fluid volume?

    Science.gov (United States)

    Sanders, Joan E; Cagle, John C; Harrison, Daniel S; Myers, Timothy R; Allyn, Kathryn J

    2013-01-01

    Adding and removing liquid from socket bladders is a means for people with limb loss to accommodate residual-limb volume change. We fit 19 people with transtibial amputation using their regular prosthetic socket with fluid bladders on the inside socket surface to undergo cycles of bladder liquid addition and removal. In each cycle, subjects sat, stood, and walked for 90 s with bladder liquid added, and then sat, stood, and walked for 90 s again with the bladder liquid removed. The amount of bladder liquid added was increased in each cycle. We used bioimpedance analysis to measure residual-limb fluid volume. Results showed that the preferred bladder liquid volume was 16.8 +/- 8.4 mL (mean +/- standard deviation), corresponding with 1.7% +/- 0.8% of the average socket volume between the bioimpedance voltage-sensing electrodes. Residual-limb fluid volume driven out of the residual limb when bladder liquid was added was typically not recovered upon subsequent bladder liquid removal. Of the 19 subjects, 15 experienced a gradual residual-limb fluid volume loss over the test session. Care should be taken when implementing adjustable socket technologies in people with limb loss. Reducing socket volume may accentuate residual-limb fluid volume loss.

  2. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Directory of Open Access Journals (Sweden)

    Tang Hai-Ming

    Full Text Available Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L. system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L. (R-R-Ry, rice-rice-Chinese milk vetch (Astragalus sinicus L. (R-R-Mv, rice-rice-rape (Brassica napus L. (R-R-Ra and rice-rice with winter fallow (R-R-Fa. The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (P<0.05 than in the R-R-Fa system during the early and late rice season. The β-glucosidase activities reached peak values at the tillering stage after residue application, and alkaline phosphatase activities reached peak values at the booting stage after residue application, respectively, the activities of β-glucosidase and alkaline phosphatase gradually decreased after this. Arylsulfatase activities reached peak values at the maturity stage. Arylamidase activities reached peak values at the maturity stage. The numbers of aerobic bacteria, actinomycete and fungus of residue treatments were significantly higher (P<0.05 than that the R-R-Ra system. However, the number of anaerobic bacteria under the R-R-Ry and R-R-Mv systems was significantly lower (P<0.05 than that under the R-R-Fa system during early rice and late rice growth stage. Thus, incorporation of winter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  3. Removal of residual nuclei following a cavitation event using low-amplitude ultrasound.

    Science.gov (United States)

    Duryea, Alexander P; Cain, Charles A; Tamaddoni, Hedieh A; Roberts, William W; Hall, Timothy L

    2014-10-01

    Microscopic residual bubble nuclei can persist on the order of 1 s following a cavitation event. These bubbles can limit the efficacy of ultrasound therapies such as shock wave lithotripsy and histotripsy, because they attenuate pulses that arrive subsequent to their formation and seed repetitive cavitation activity at a discrete set of sites (cavitation memory). Here, we explore a strategy for the removal of these residual bubbles following a cavitation event, using low-amplitude ultrasound pulses to stimulate bubble coalescence. All experiments were conducted in degassed water and monitored using high-speed photography. In each case, a 2-MHz histotripsy transducer was used to initiate cavitation activity (a cavitational bubble cloud), the collapse of which generated a population of residual bubble nuclei. This residual nuclei population was then sonicated using a 1 ms pulse from a separate 500-kHz transducer, which we term the bubble removal pulse. Bubble removal pulse amplitudes ranging from 0 to 1.7 MPa were tested, and the backlit area of shadow from bubbles remaining in the field following bubble removal was calculated to quantify efficacy. It was found that an ideal amplitude range exists (roughly 180 to 570 kPa) in which bubble removal pulses stimulate the aggregation and subsequent coalescence of residual bubble nuclei, effectively removing them from the field. Further optimization of bubble removal pulse sequences stands to provide an adjunct to cavitation-based ultrasound therapies such as shock wave lithotripsy and histotripsy, mitigating the effects of residual bubble nuclei that currently limit their efficacy.

  4. Removal of Cu(Ⅱ) from acidic electroplating effluent by biochars generated from crop straws

    Institute of Scientific and Technical Information of China (English)

    Xuejiao Tong; Renkou Xu

    2013-01-01

    The removal efficiency of copper (Cu(Ⅱ)) from an actual acidic electroplating effluent by biochars generated from canola,rice,soybean and peanut straws was investigated.The biochars simultaneously removed Cu(Ⅱ) from the effluent,mainly through the mechanisms of adsorption and precipitation,and neutralized its acidity.The removal efficiency of Cu(Ⅱ) by the biochars followed the order:peanut straw char > soybean straw char > canola straw char > rice straw char >> a commercial activated carbonaceous material,which is consistent with the alkalinity of the biochars.The pH of the effluent was a key factor determining the removal efficiency of Cu(Ⅱ)by biochars.Raising the initial pH of the effluent enhanced the removal of Cu(Ⅱ) from it.The optimum pyrolysis temperature was 400℃ for producing biochar from crop straws for acidic wastewater treatment,and the optimum reaction time was 8 hr.

  5. The impact of altered herbicide residues in transgenic herbicide-resistant crops on standard setting for herbicide residues

    NARCIS (Netherlands)

    Kleter, G.A.; Unsworth, J.B.; Harris, C.A.

    2011-01-01

    The global area covered with transgenic (genetically modified) crops has rapidly increased since their introduction in the mid-1990s. Most of these crops have been rendered herbicide resistant, for which it can be envisaged that the modification has an impact on the profile and level of herbicide re

  6. The Effect of Crop Residue and Different NPK Fertilizer Rates on yield Components and Yield of Wheat

    Directory of Open Access Journals (Sweden)

    fatemeh khamadi

    2017-03-01

    Full Text Available Introduction Integrated nutrient management involving crop residue/green manures and chemical fertilizer is potential alternative to provide a balanced supply of nutrients, enhance soil quality and thereby sustain higher productivity. The present experiment was undertaken to evaluate the effect of different crop residue management practices and NPK levels on yield components and yield of wheat. Materials and methods Field experiments were conducted during 2012-2014 at department of agronomy, Chamran University. Experiment was laid out in a randomized block designs in split plot arrangement. With three replications. Crop residues were assigned to main plot consistent CR1: wheat residue; CR2: rape residue; CR3: barley residue; CR4: barley residue + vetch; CR5: wheat straw + mungbean; CR6: vetch residue; CR7: mungbean residue; CR8: No residue incorporation as main plot and three NPK fertilizer rates: F1: (180N-120P-100K kg.ha-1; F2: (140N-90P-80K kg.ha-1; F3: (90N-60P-40K kg.ha-1 as sub plots. Twelve hills were collected at physiological maturity for measuring yield components from surrounding area of grain yield harvest area. Yield components, viz. number of spike per m2, seed per spike, 1000- grain weight, plant height were measured. Grain and straw yields were recorded from the central 5 m2 grain yield harvest area of each treatment and harvest index was calculated. Data were subjected to analysis by SAS and mean companions were performed using the Duncan multiple range test producer. Also, graphs were drawn in Excel software. Results and discussion The result of analysis variance showed significant difference between crop residues for evaluated traits. The result indicated that the highest biological and grain yield was obtained when wheat treated with CR5: wheat straw + mungbean (green manure and CR4: barley straw + vetch (green manure. Biological and grain yield increased 31 and 26% respectively by CR5 comparing with control. The highest

  7. Development of the crop residue and rangeland burning in the 2014 National Emissions Inventory using information from multiple sources

    Science.gov (United States)

    Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. One component of the biomass burning inventory, crop residue burning, has been poorly characterized in the National Emissions I...

  8. Sustainability of soil fertility and the use of lignocellulosic crop harvest residues for the production of biofuels: a literature review

    NARCIS (Netherlands)

    Reijnders, L.

    2013-01-01

    Use of lignocellulosic crop harvest residues for liquid or gaseous biofuel production may impact soil quality, long-term soil fertility and the major determinants of the latter, stocks of soil organic carbon and nutrients. When soil organic carbon stocks of mineral cropland soils are to be maintaine

  9. Evaluation of certain crop residues for carbohydrate and protein fractions by cornell net carbohydrate and protein system

    Directory of Open Access Journals (Sweden)

    Venkateswarulu Swarna

    2015-06-01

    Full Text Available Four locally available crop residues viz., jowar stover (JS, maize stover (MS, red gram straw (RGS and black gram straw (BGS were evaluated for carbohydrate and protein fractions using Cornell Net Carbohydrate and Protein (CNCP system. Lignin (% NDF was higher in legume straws as compared to cereal stovers while Non-structural carbohydrates (NSC (% DM followed the reverse trend. The carbohydrate fractions A and B1 were higher in BGS while B2 was higher in MS as compared to other crop residues. The unavailable cell wall fraction (C was higher in legume straws when compared to cereal stovers. Among protein fractions, B1 was higher in legume straws when compared to cereal stovers while B2 was higher in cereal stovers as compared to legume straws. Fraction B3 largely, bypass protein was highest in MS as compared to other crop residues. Acid detergent insoluble crude protein (ADICP (% CP or unavailable protein fraction C was lowest in MS and highest in BGS. It is concluded that MS is superior in nutritional value for feeding ruminants as compared to other crop residues.

  10. Neonicotinoid insecticide removal by prairie strips in row-cropped watersheds with historical seed coating use

    Science.gov (United States)

    Hladik, Michelle; Bradbury, Steven; Schulte, Lisa A.; Helmers, Matthew; Witte, Christopher; Kolpin, Dana W.; Garrett, Jessica D.; Harris, Mary

    2017-01-01

    Neonicotinoids are a widely used class of insecticides that are commonly applied as seed coatings for agricultural crops. Such neonicotinoid use may pose a risk to non-target insects, including pollinators and natural enemies of crop pests, and ecosystems. This study assessed neonicotinoid residues in groundwater, surface runoff water, soil, and native plants adjacent to corn and soybean crop fields with a history of being planted with neonicotinoid-treated seeds from 2008-2013. Data from six sites with the same crop management history, three with and three without in-field prairie strips, were collected in 2015-2016, 2-3 years after neonicotinoid (clothianidin and imidacloprid) seed treatments were last used. Three of the six neonicotinoids analyzed were detected in at least one environmental matrix: the two applied as seed coatings on the fields (clothianidin and imidacloprid) and another widely used neonicotinoid (thiamethoxam). Sites with prairie strips generally had lower concentrations of neonicotinoids: groundwater and footslope soil neonicotinoid concentrations were significantly lower in the sites with prairie strips than those without; mean concentrations for groundwater were 11 and 20 ng/L (p = 0.048) and seed treatments continued. There were no detections (limit of detection: 1 ng/g) of neonicotinoids in the foliage or roots of plants comprising prairie strips, indicating a low likelihood of exposure to pollinators and other insects visiting these plants following the cessation of seed coating use. Offsite transport of neonicotinoids to aquatic systems through the groundwater and surface water were furthermore reduced with prairie strips. This study demonstrates the potential for prairie strips comprising 10% of an agricultural catchment to mitigate the non-target impacts of neonicotinoids.

  11. Modelling the dissipation and leaching of two herbicides in decomposing mulch of crop residues

    Science.gov (United States)

    Aslam, Sohaib; Iqbal, Akhtar; Lafolie, François; Recous, Sylvie; Benoit, Pierre; Garnier, Patricia

    2013-04-01

    Conservation agricultural practices are increasingly adopted because of ecosystem services such as conservation of soil and water resources. These farming systems are characterized mainly by the presence of mulch made of residues of harvested or cover crops on soil surface. The mulch can intercept and retain applied pesticides depending on pesticide molecule and rainfall timing. The pesticide wash-off from mulch is considered a key process in pesticide fate and can have effects on degradation and transport processes. This work highlights a modelling approach to study the pesticide wash-off from mulch residues and their further transport in soil under two rainfall regimes. Transformation and leaching of two herbicides, s-metolachlor and glyphosate, was studied and simulated by Pastis-mulch model. A pesticide module describing pesticide degradation in mulch and soil was coupled to a transport model including a mulch module. The model was tested to simulate the pesticide dissipation, wash-off from mulch and further leaching in soil. Pesticide degradation parameters in mulch were estimated from incubation experiments with 14C-labelled molecules in small cylinders. The model was then tested using the data obtained through a soil column experiment (reconstructed soil cores :15 cm diameter x 35 cm depth), a mulch of Zea mais + Doliquos lablab and with two treatments varied by water regimes: i) frequent rain (temperate, twice a week) with week intensity (6 mm/hr); and ii) occasional rain (tropical, twice a month) with stronger intensity (20 mm/hr). Columns were incubated at 20 °C for 84 days to monitor soil water, C, N and pesticide dynamics. Model successfully simulated the experimental data of pesticide dissipation in mulch residues. Results showed that the rain regime affected more S-metolachlor than glyphosate behavior. The simulated results indicated also that the dynamics in mulch of the two molecules differed according to the rain treatment. Glyphosate showed a

  12. The performance of activated carbons from sugarcane bagasse, babassu, and coconut shells in removing residual chlorine

    Energy Technology Data Exchange (ETDEWEB)

    Jaguaribe, E.F.; Araujo, L.P. [Paraiba Univ., Joao Pessoa, PB (Brazil). Centro de Ciencias da Saude. Lab. de Carvao Ativado]. E-mail:emersonjaguaribe@globo.com; Medeiros, L.L.; Barreto, M.C.S. [Paraiba Univ., Joao Pessoa, PB (Brazil). Dept. de Quimica]. E-mail: luciana-lucena@bol.com.br

    2005-03-01

    The capacity of activated carbons obtained from different raw materials, such as sugarcane bagasse, babassu (Orbygnia speciosa), and coconut (Cocus nucifera) shells, to remove residual chlorine is studied. The influence of particle size and time of contact between particles of activated carbon and the chlorinated solution were taken into account. The adsorptive properties of the activated carbons were measured by gas adsorption (BET method), using an ASAP 2010 porosimeter, and liquid phase adsorption, employing iodine and methylene blue adsorbates. The activated carbon from sugarcane bagasse was the only adsorbent capable of removing 100% of the residual chlorine. (author)

  13. Soil Organic Matter Quality of an Oxisol Affected by Plant Residues and Crop Sequence under No-Tillage

    Science.gov (United States)

    Cora, Jose; Marcelo, Adolfo

    2013-04-01

    Plant residues are considered the primarily resource for soil organic matter (SOM) formation and the amounts and properties of plant litter are important controlling factors for the SOM quality. We determined the amounts, quality and decomposition rate of plant residues and the effects of summer and winter crop sequences on soil organic C (TOC) content, both particulate organic C (POC) and mineral-associated organic C (MOC) pools and humic substances in a Brazilian Rhodic Eutrudox soil under a no-tillage system. The organic C analysis in specifics pools used in this study was effective and should be adopted in tropical climates to evaluate the soil quality and the sustainability of various cropping systems. Continuous growth of soybean (Glycine max L. Merrill) on summer provided higher contents of soil POC and continuous growth of maize (Zea mays L.) provided higher soil humic acid and MOC contents. Summer soybean-maize rotation provided the higher plant diversity, which likely improved the soil microbial activity and the soil organic C consumption. The winter sunn hemp (Crotalaria juncea L.), pigeon pea (Cajanus cajan (L.) Millsp), oilseed radish (Raphanus sativus L.) and pearl millet (Pennisetum americanum (L.) Leeke) enhanced the soil MOC, a finding that is attributable to the higher N content of the crop residue. Sunn hemp and pigeon pea provided the higher soil POC content. Sunn hemp showed better performance and positive effects on the SOM quality, making it a suitable winter crop choice for tropical conditions with a warm and dry winter.

  14. Crop residues as driver for N2O emissions from a sandy loam soil

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Petersen, Søren O.; Chirinda, Ngonidzashe

    2017-01-01

    Nitrogen (N) cycling within agriculture constitutes a source of direct and indirect emissions of the potent greenhouse gas nitrous oxide (N2O). We analysed relationships between N2O emissions and C and N balances of four arable cropping systems under conventional or organic management within a long......-term experiment on a loamy sand soil at Foulum in Denmark. All cropping systems included winter wheat, a leguminous crop (faba bean or grass-clover), potato and spring barley grown in different 4-crop rotations varying in strategies for N supply (fertilizer/manure type and rate, use of catch crops and green...... manure). Crops in both organic and conventional systems received N at rates below the optimum for crop production. Soil N2O emissions were monitored in 2008–2009 in six selected crops which could be combined with data from other monitoring programs to calculate N2O emission factors for each of the 16...

  15. Bioconversion of sugar cane crop residues with white-rot fungiPleurotus sp.

    Science.gov (United States)

    Ortega, G M; Martínez, E O; Betancourt, D; González, A E; Otero, M A

    1992-07-01

    Four mushroom strains ofPleurotus spp. were cultivated on sugar cane crop residues for 30 days at 26°C. Biochemical changes affected the substrate as a result of fungal growth, in terms of nitrogen, lignin, cellulose and hemicellulose contents. All strains showed a strong ligninolytic activity together with variable cellulolytic and xylanolytic action.Pleurotus sajor-caju attacked lignin and cellulose at the same rate, showing a degradation of 47% and 55%, respectively. A better balance was shown by theP. ostreatus-P. pulmonarius hybrid, which exhibited the poorest cellulolytic action (39%) and the highest ligninolytic activity (67%). The average composition of mushroom fruit bodies, in terms of nitrogen, carbohydrates, fats and amino acid profiles, was determined. Crude protein and total carbohydrate varied from 23% to 33% and 36% to 68% of dry matter, respectively. Fat ranged from 3.3% to 4.7% and amino acid content from 12.2% to 22.2%. Slight evidence for a nitrogen fixing capability was encountered in the substrate to fruit body balance.

  16. Cellulosic biofuels from crop residue and groundwater extraction in the US Plains: the case of Nebraska.

    Science.gov (United States)

    Sesmero, Juan P

    2014-11-01

    This study develops a model of crop residue (i.e. stover) supply and derived demand for irrigation water accounting for non-linear effects of soil organic matter on soil's water holding capacity. The model is calibrated for typical conditions in central Nebraska, United States, and identifies potential interactions between water and biofuel policies. The price offered for feedstock by a cost-minimizing plant facing that stover supply response is calculated. Results indicate that as biofuel production volumes increase, soil carbon depletion per unit of biofuel produced decreases. Consumption of groundwater per unit of biofuel produced first decreases and then increases (after a threshold of 363 dam(3) of biofuels per year) due to plants' increased reliance on the extensive margin for additional biomass. The analysis reveals a tension between biofuel and water policies. As biofuel production raises the economic benefits of relaxing water conservation policies (measured by the "shadow price" of water) increase. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. The Removal and Remediation of Phenanthrene and Pyrene in Soil by Mixed Cropping of Alfalfa and Rape

    Institute of Scientific and Technical Information of China (English)

    PAN Sheng-wang; WEI Shi-qiang; YUAN Xin; CAO Sheng-xian

    2008-01-01

    The mechanisms and efficiencies of the removal and remediation of polycyclic aromatic hydrocarbons (PAHs) in soils by different planting patterns with rape (Brassica campeslris) and alfalfa (Medicago sativa) were studied by pot experiments in a greenhouse. Results showed that the remediation efficiencies under mixed cropping of alfalfa and rape significantly exceeded those under single cropping when the initial concentrations of phenanthrene and pyrene were at 20.05-322.06 mg kg-1 and 20.24-321.42 mg kg-1, respectively. After 70 days plantation of crops, the contents of extractable PAHs in soils under mixed cropping were much lower than those under single cropping. About 65.17-83.52% of phenanthrene and 60.09%-75.34% of pyrene was removed from the soils under mixed cropping, respectively, which were averagely 43.26 and 40.38% for phenanthrene, and 11.03 and 16.29% for pyren higher than those under single cropping. Alfalfa or rape did absorb and accumulate PAHs from the soils apparently; the PAHs concentrations in plants monotonically increased with the increase of initial PAHs concentrations in soil; the accumulations of PAHs in plants showed following sequence as roots> above parts, phenanthrene> pyrene and single cropping> mixed cropping at same contamination level. Despite the presence of vegetation significantly enhanced the remediation of PAHs in soils, contributions of abiotic loss, plant uptake, accumulation and microbial degradation was much lower than those of plant-microbial interactions in the process of phytoremediation. Thus plant-microbial interactions are the main mechanisms for the remediation enhancement of soil PAHs pollution under mixed cropping models. Results suggested a feasibility of the establishment of multi-species phytoremediation for the improvement of remediation efficiencies of PAHs, which may decrease accumulations of PAHs in crops and thus reduce their risks.

  18. Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Teixeira

    2013-10-01

    Full Text Available Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp. residues to the short-term CO2-C loss, we studied the influence of several tillage systems: heavy offset disk harrow (HO, chisel plow (CP, rotary tiller (RT, and sugarcane mill tiller (SM in 2008, and CP, RT, SM, moldboard (MP, and subsoiler (SUB in 2009, with and without sugarcane residues relative to no-till (NT in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47 % and 41 %, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

  19. Remote sensing weeds, cover crop residue, and tillage practices in soybean

    Science.gov (United States)

    Koger, Clifford Hubert

    Research was conducted to evaluate the potential of remote sensing for detecting weeds in soybean. The first objective was to evaluate the potential of multispectral imagery for detection of late-season weed-infestations. The second objective was to identify bands derived from hyperspectral data capable of discriminating small, early-season pitted morningglory intermixed with soybean from weed-free soybean in different tillage and cover crop residue systems. The final objective was to determine the success of wavelet-based analysis of ground-collected hyperspectral data for discriminating reflectance patterns of pitted morningglory intermixed with soybean from weed-free soybean. Late-season weed infestations were discriminated from weed-free soybean with at least 90% accuracy when using green, red, and near-infrared spectral bands and a normalized difference vegetation index as classification variables in discriminant analysis. Discriminant analysis functions formed for one data set and tested on another set were 81 to 90% accurate in discriminating weed-infestations when soybean growth stage between data sets did not differ substantially. For the second objective, reflectance data were collected between 350 and 2,500 nm in 2151 discrete bands, with spectral bandwidths of 1.4 nm between 350 and 1050 nm and 1.0 nm from 1000 to 2500 nm. Eight 50-nm bands (1 ultraviolet, 2 visible, 4 near-infrared, 1 mid-infrared) were used to classify reflectance properties of pitted morningglory intermixed with soybean from weed-free soybean with 83 to 100% accuracy within the different tillage/residue systems. Pitted morningglory growth stage influenced detection capabilities more than tillage and residue systems. The ability to discriminate pitted morningglory intermixed with soybean from weed-free soybean was attributed to differences in reflectance properties of pitted morningglory and soybean, not from increase in total vegetation biomass in the pitted morningglory intermixed

  20. Thermal Hydraulic Analysis of a Passive Residual Heat Removal System for an Integral Pressurized Water Reactor

    Directory of Open Access Journals (Sweden)

    Junli Gou

    2009-01-01

    Full Text Available A theoretical investigation on the thermal hydraulic characteristics of a new type of passive residual heat removal system (PRHRS, which is connected to the reactor coolant system via the secondary side of the steam generator, for an integral pressurized water reactor is presented in this paper. Three-interknited natural circulation loops are adopted by this PRHRS to remove the residual heat of the reactor core after a reactor trip. Based on the one-dimensional model and a simulation code (SCPRHRS, the transient behaviors of the PRHRS as well as the effects of the height difference between the steam generator and the heat exchanger and the heat transfer area of the heat exchanger are studied in detail. Through the calculation analysis, it is found that the calculated parameter variation trends are reasonable. The higher height difference between the steam generator and the residual heat exchanger and the larger heat transfer area of the residual heat exchanger are favorable to the passive residual heat removal system.

  1. Effectiveness of 2 chemomechanical caries removal methods on residual bacteria in dentin of primary teeth.

    Science.gov (United States)

    El-Tekeya, Magda; El-Habashy, Laila; Mokhles, Nadia; El-Kimary, Engy

    2012-01-01

    The purpose of this study was to evaluate the effectiveness of 2 chemomechanical caries removal methods-Carisolv and Papacarie-on the residual cariogenic bacteria in the dentin of primary teeth vs traditional hand excavation. Forty-five primary teeth were divided into 3 groups, according to the caries removal method used. Carious dentin samples were taken, then all softened dentin was removed, and a second sample was taken when the cavities were clinically caries-free, All teeth were filled with composite resins. All dentin samples were serially diluted and cultured anaerobically on different agar plates: blood agar, Mitis salivarius agar, and Rogosa agar plates. Colony forming units were determined for total bacterial, mutans streptococci, and lactobacilli counts. The 3 caries removal methods significantly reduced the residual cariogenic bacteria for the total bacterial, mutans streptococci, and lactobacilli counts. There was a statistically significant difference between Papacarie and both Carisolv and hand excavation methods, with Papacarie being more effective in caries removal and causing more reduction in bacterial count. Papacarie is significantly more efficient in reducing the residual cariogenic bacteria in the dentin of primary teeth vs both Carisolv and the hand excavation method.

  2. Ghg and Aerosol Emission from Fire Pixel during Crop Residue Burning Under Rice and Wheat Cropping Systems in North-West India

    Science.gov (United States)

    Acharya, Prasenjit; Sreekesh, S.; Kulshrestha, Umesh

    2016-10-01

    Emission of smoke and aerosol from open field burning of crop residue is a long-standing subject matter of atmospheric pollution. In this study, we proposed a new approach of estimating fuel load in the fire pixels and corresponding emissions of selected GHGs and aerosols i.e. CO2, CO, NO2, SO2, and total particulate matter (TPM) due to burning of crop residue under rice and wheat cropping systems in Punjab in north-west India from 2002 to 2012. In contrasts to the conventional method that uses RPR ratio to estimate the biomass, fuel load in the fire pixels was estimated as a function of enhanced vegetation index (EVI). MODIS fire products were used to detect the fire pixels during harvesting seasons of rice and wheat. Based on the field measurements, fuel load in the fire pixels were modelled as a function of average EVI using second order polynomial regression. Average EVI for rice and wheat crops that were extracted through Fourier transformation were computed from MODIS time series 16 day EVI composites. About 23 % of net shown area (NSA) during rice and 11 % during wheat harvesting seasons are affected by field burning. The computed average fuel loads are 11.32 t/ha (±17.4) during rice and 10.89 t/ha (±8.7) during wheat harvesting seasons. Calculated average total emissions of CO2, CO, NO2, SO2 and TPM were 8108.41, 657.85, 8.10, 4.10, and 133.21 Gg during rice straw burning and 6896.85, 625.09, 1.42, 1.77, and 57.55 Gg during wheat burning. Comparison of estimated values shows better agreement with the previous concurrent estimations. The method, however, shows its efficiency parallel to the conventional method of estimation of fuel load and related pollutant emissions.

  3. Steady characteristic investigation on passive residual heat removal system of Chinese advanced PWR

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Thermal-hydraulic characteristic investigation on passive residual heat removal system(PRHRS)of Chinese advanced PWR was conducted to provide input data for PRHRS design and to demonstrate the feasibility of unique design features.A total of 237 sets of test data at steady state have been obtained and the main influence factors on the two-phase natural circulation flow rate and residual heat removal capability were identified.On the basis of theory analysis,a correlation of two-phase natural circulation was obtained,and relative errors of 95% test data were less than±16%.There is a considerable effect of the system status parameters on the threshold of height between heat source and heat sink,and its correlation of two-phase natural circulation system has been obtained.The steady characteristic research shows that PRHRS has the capability of removing the core decay power through natural circulation.

  4. Impact of climate variability on N and C flux within the life cycle of biofuels produced from crop residues

    Science.gov (United States)

    Pourhashem, G.; Block, P. J.; Adler, P. R.; Spatari, S.

    2013-12-01

    Biofuels from agricultural feedstocks (lignocellulose) are under development to meet national policy objectives for producing domestic renewable fuels. Using crop residues such as corn stover as feedstock for biofuel production can minimize the risks associated with food market disruption; however, it demands managing residue removal to minimize soil carbon loss, erosion, and to ensure nutrient replacement. Emissions of nitrous oxide and changes to soil organic carbon (SOC) are subject to variability in time due to local climate conditions and cultivation practices. Our objective is to investigate the effect of climate inputs (precipitation and temperature) on biogeochemical greenhouse gas (GHG) emissions (N2O and SOC expressed as CO2) within the life cycle of biofuels produced from agricultural residues. Specifically, we investigate the impact of local climate variability on soil carbon and nitrogen fluxes over a 20-year biorefinery lifetime where biomass residue is used for lignocellulosic ethanol production. We investigate two cases studied previously (Pourhashem et al, 2013) where the fermentable sugars in the agricultural residue are converted to ethanol (biofuel) and the lignin byproduct is used in one of two ways: 1) power co-generation; or 2) application to land as a carbon/nutrient-rich amendment to soil. In the second case SOC losses are mitigated through returning the lignin component to land while the need for fertilizer addition is also eliminated, however in both cases N2O and SOC are subject to variability due to variable climate conditions. We used the biogeochemical model DayCent to predict soil carbon and nitrogen fluxes considering soil characteristics, tillage practices and local climate (e.g. temperature and rainfall). We address the impact of climate variability on the soil carbon and nitrogen fluxes by implementing a statistical bootstrap resampling method based on a historic data set (1980 to 2000). The ensuing probabilistic outputs from the

  5. Long-term tillage and crop rotation effects on residual nitrate in the crop root zone and nitrate accumulation in the intermediate vadose zone

    Science.gov (United States)

    Katupitiya, A.; Eisenhauer, D.E.; Ferguson, R.B.; Spalding, R.F.; Roeth, F.W.; Bobier, M.W.

    1997-01-01

    Tillage influences the physical and biological environment of soil. Rotation of crops with a legume affects the soil N status. A furrow irrigated site was investigated for long-term tillage and crop rotation effects on leaching of nitrate from the root zone and accumulation in the intermediate vadose zone (IVZ). The investigated tillage systems were disk-plant (DP), ridge-till (RT) and slot-plant (SP). These tillage treatments have been maintained on the Hastings silt loam (Udic Argiustoll) and Crete silt loam (Pachic Argiustoll) soils since 1976. Continuous corn (CC) and corn soybean (CS) rotations were the subtreatments. Since 1984, soybeans have been grown in CS plots in even calendar years. All tillage treatments received the same N rate. The N rate varied annually depending on the root zone residual N. Soybeans were not fertilized with N-fertilizer. Samples for residual nitrate in the root zone were taken in 8 of the 15 year study while the IVZ was only sampled at the end of the study. In seven of eight years, root zone residual soil nitrate-N levels were greater with DP than RT and SP. Residual nitrate-N amounts were similar in RT and SP in all years. Despite high residual nitrate-N with DP and the same N application rate, crop yields were higher in RT and SP except when DP had an extremely high root zone nitrate level. By applying the same N rates on all tillage treatments, DP may have been fertilized in excess of crop need. Higher residual nitrate-N in DP was most likely due to a combination of increased mineralization with tillage and lower yield compared to RT and SP. Because of higher nitrate availability with DP, the potential for nitrate leaching from the root zone was greater with DP as compared to the RT and SP tillage systems. Spring residual nitrate-N contents of DP were larger than RT and SP in both crop rotations. Ridge till and SP systems had greater nitrate-N with CS than CC rotations. Nitrate accumulation in IVZ at the upstream end of the

  6. Cofermentation of energy crops and organic residues; Ergebnisse der Kovergaerung von Energiepflanzen und organischen Reststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Linke, B. [Institut fuer Agrartechnik Bornim e.V. (ATB), Potsdam-Bornim (Germany); Vollmer, G.R. [Biotechnologie Nordhausen (BTN) (Germany)

    2002-07-01

    There are currently more than 1500 agricultural biogas plans in Germany, most of which work by the liquid fermentation principle which is commercially available. At a mean hydraulic time of residue of 20 - 30 days and a charge of about 1.5 to 4 kg of organic matter m{sup -1}d{sup -1}, about 350 - 550 l of biogas can be produced per kg of organic matter (liquid or solid manure). Biogas yields are higher for cofermentation of liquid manure with energy crops and/or high-energy organic residues. Some figures are given: About 1000 l per kg{sup -1} for beetroot, pressed pellets of rape, sugarbeet, or rye, 600 - 700 l per kg{sup -1} for grass, malt residuum, sugar pulp, grape cake or potato pulp. In the case of silo-fermented corn, yields were higher than reported in earlier publications, i.e. about 800 instead of 200 l per kg{sup -1}. [German] Die Gewinnung von Biogas aus Guelle, Stallmist, pflanzlichen Biomassen oder organischen Reststoffen aus der Agro- oder Lebensmittelindustrie leistet heute durch das EEG in ueber 1500 Landwirtschaftsbetrieben Deutschlands einen Beitrag zur Sicherung des Einkommens. Die Landwirte nutzen hierfuer vorwiegend die Technik der Fluessigvergaerung, die von zahlreichen Firmen auf dem Markt angeboten werden. Bei mittleren hydraulischen Verweilzeiten von 20 bis 30 Tagen oder Faulraumbelastungen von etwa 1,5 bis 4 kg oS m{sup -3} d{sup -1} koennen aus Guelle oder Stallmist je kg zugefuehrte organische Substanz 350 bis 550 l Biogas gewonnen werden. Deutlich hoehere spezifische Biogasausbeuten erhaelt man durch die gemeinsame Vergaerung von Guelle mit Energiepflanzen und/oder energiereichen organischen Reststoffen (Kofermentation). Fuer Ruebensilage, Rapskuchen, Zuckerrueben-Pressschnitzel oder Roggen kann man oS-Biogasausbeuten von etwa 1000 l kg{sup -1} rechnen, waehrend sich der entsprechende Wert fuer Graeser, Schlempe, Melasse, Trester oder Kartoffelpuelpe im Bereich von 600 bis 700 l kg{sup -1} bewegt. Der in der Fachliteratur oft zu

  7. Combining mechanical rhizome removal and cover crops for Elytrigia repens control in organic barley systems

    DEFF Research Database (Denmark)

    Melander, B; Nørremark, M; Kristensen, E F

    2013-01-01

    of vegetative propagules located within the plough layer to allow for quick re-establishment of a plant cover. A field experiment comparing the effects of conventional practices (stubble cultivation) with different combinations of rotary cultivation (One, Two or four passes) and cover crops (none vs. rye......-vetch-mustard mixture) on Elytrigia repens rhizome removal, shoot growth and suppression of a subsequent barley crop was examined in two growing seasons. Four passes with a modified rotary cultivator, where each pass was followed by rhizome removal, reduced E. repens shoot growth in barley by 84% and 97%. In general...

  8. Biogas Production by Co-Digestion of Goat Manure with Three Crop Residues

    Science.gov (United States)

    Zhang, Tong; Liu, Linlin; Song, Zilin; Ren, Guangxin; Feng, Yongzhong; Han, Xinhui; Yang, Gaihe

    2013-01-01

    Goat manure (GM) is an excellent raw material for anaerobic digestion because of its high total nitrogen content and fermentation stability. Several comparative assays were conducted on the anaerobic co-digestion of GM with three crop residues (CRs), namely, wheat straw (WS), corn stalks (CS) and rice straw (RS), under different mixing ratios. All digesters were implemented simultaneously under mesophilic temperature at 35±1 °C with a total solid concentration of 8%. Result showed that the combination of GM with CS or RS significantly improved biogas production at all carbon-to-nitrogen (C/N) ratios. GM/CS (30:70), GM/CS (70:30), GM/RS (30:70) and GM/RS (50:50) produced the highest biogas yields from different co-substrates (14840, 16023, 15608 and 15698 mL, respectively) after 55 d of fermentation. Biogas yields of GM/WS 30:70 (C/N 35.61), GM/CS 70:30 (C/N 21.19) and GM/RS 50:50 (C/N 26.23) were 1.62, 2.11 and 1.83 times higher than that of CRs, respectively. These values were determined to be the optimal C/N ratios for co-digestion. However, compared with treatments of GM/CS and GM/RS treatments, biogas generated from GM/WS was only slightly higher than the single digestion of GM or WS. This result was caused by the high total carbon content (35.83%) and lignin content (24.34%) in WS, which inhibited biodegradation. PMID:23825574

  9. Enhanced irreversible sorption of carbaryl to soils amended with crop-residue-derived biochar.

    Science.gov (United States)

    Qiu, Yuping; Wu, Minwei; Jiang, Jing; Li, Liang; Sheng, G Daniel

    2013-09-01

    The irreversible sorption-desorption of carbaryl in five soil types with crop-residue-derived biochar (CBC) amendment was determined. CBC has lower surface area and micropores volume than wood-based biochar and charcoal. However, CBC amendment (0.5%) still significantly enhanced the hysteresis effect on soils, with a 1.7- to 2.8-fold increase in the hysteresis index (HI) values. The HI values increased exponentially with the increased amount of CBC but decreased exponentially with the increased amount of soil organic matter (SOM%). Furthermore, the irreversible carbaryl sorption (qirr) and the irreversibility index (Iirr) values were proportional to the amount of CBC (0-1.0%) in soils. Likewise, the SOM-rich soil (S3) was washed ten times to reduce its SOM% to evaluate the influence of the dissolved organic matter (DOM) in the soils on the irreversible sorption. The Iirr values of the unamended S3 increased as the number of sorption-desorption cycles increased, whereas those of the 1.0% CBC-amended S3 decreased. In addition, the Iirr values of the unwashed S3 were lower than those of the washed S3. By contrast, the Iirr values of the 1.0% CBC-amended S3 soil were higher in the unwashed samples than in the washed samples. These results suggested that DOM had opposite effects on the irreversible carbaryl sorption by unamended and CBC-amended soils. The DOM release may expose more irreversible adsorption sites in the soils and may cover the surface of the CBC to form a desorption-resistant fraction in its mesopore or macropore regions, thereby preventing the desorption of adsorbed carbaryl molecules.

  10. Biogas production by co-digestion of goat manure with three crop residues.

    Science.gov (United States)

    Zhang, Tong; Liu, Linlin; Song, Zilin; Ren, Guangxin; Feng, Yongzhong; Han, Xinhui; Yang, Gaihe

    2013-01-01

    Goat manure (GM) is an excellent raw material for anaerobic digestion because of its high total nitrogen content and fermentation stability. Several comparative assays were conducted on the anaerobic co-digestion of GM with three crop residues (CRs), namely, wheat straw (WS), corn stalks (CS) and rice straw (RS), under different mixing ratios. All digesters were implemented simultaneously under mesophilic temperature at 35±1 °C with a total solid concentration of 8%. Result showed that the combination of GM with CS or RS significantly improved biogas production at all carbon-to-nitrogen (C/N) ratios. GM/CS (30:70), GM/CS (70:30), GM/RS (30:70) and GM/RS (50:50) produced the highest biogas yields from different co-substrates (14840, 16023, 15608 and 15698 mL, respectively) after 55 d of fermentation. Biogas yields of GM/WS 30:70 (C/N 35.61), GM/CS 70:30 (C/N 21.19) and GM/RS 50:50 (C/N 26.23) were 1.62, 2.11 and 1.83 times higher than that of CRs, respectively. These values were determined to be the optimal C/N ratios for co-digestion. However, compared with treatments of GM/CS and GM/RS treatments, biogas generated from GM/WS was only slightly higher than the single digestion of GM or WS. This result was caused by the high total carbon content (35.83%) and lignin content (24.34%) in WS, which inhibited biodegradation.

  11. Biogas production by co-digestion of goat manure with three crop residues.

    Directory of Open Access Journals (Sweden)

    Tong Zhang

    Full Text Available Goat manure (GM is an excellent raw material for anaerobic digestion because of its high total nitrogen content and fermentation stability. Several comparative assays were conducted on the anaerobic co-digestion of GM with three crop residues (CRs, namely, wheat straw (WS, corn stalks (CS and rice straw (RS, under different mixing ratios. All digesters were implemented simultaneously under mesophilic temperature at 35±1 °C with a total solid concentration of 8%. Result showed that the combination of GM with CS or RS significantly improved biogas production at all carbon-to-nitrogen (C/N ratios. GM/CS (30:70, GM/CS (70:30, GM/RS (30:70 and GM/RS (50:50 produced the highest biogas yields from different co-substrates (14840, 16023, 15608 and 15698 mL, respectively after 55 d of fermentation. Biogas yields of GM/WS 30:70 (C/N 35.61, GM/CS 70:30 (C/N 21.19 and GM/RS 50:50 (C/N 26.23 were 1.62, 2.11 and 1.83 times higher than that of CRs, respectively. These values were determined to be the optimal C/N ratios for co-digestion. However, compared with treatments of GM/CS and GM/RS treatments, biogas generated from GM/WS was only slightly higher than the single digestion of GM or WS. This result was caused by the high total carbon content (35.83% and lignin content (24.34% in WS, which inhibited biodegradation.

  12. Strategy of Utilization of Locally Available Crop Residues and By-Products for Livestock Feeding in Tunisia

    OpenAIRE

    Moujahed-Raach, A.; Moujahed, N.; Kayouli, C

    2001-01-01

    Important quantifies of crops residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country, but most of them are localised in the northern region. Some of the agricultural wastes are available in import...

  13. Response of some crops grown in rotation with wheat to the residues of sulfonylurea herbicides in Khuzestan province

    Directory of Open Access Journals (Sweden)

    Reza Poorazar

    2016-04-01

    Full Text Available Maize and mungbean rotational responses to sulfonylurea herbicides applied on wheat at the previous year were investigated in two separated experiments at Ahvaz in 2006 and 2007. In the first experiment, 10 treatments of herbicides applied to wheat at the year before planting, and after wheat harvesting, the maize crop was planted. Treatments consisted of Chevaliar (idosulfosulfuron + mesosulfuron at 0.4L/ha, Apyrus (sulfosulfuron at 28, 42, 56 and 68 g/ha, megaton (chlorsulfuron at 20 g/ha, bromicide + topic ("bromoxynil + MCPA"+ clodinafop-propargyl at 1.5+0.8 L/ha, Total (sulfosulfuron +mesosulfuron at 45 g/ha, atlantis (idosulfuron + mesosulfuron at 1.5 L/ha and non-treated control. The second experiment was the same as the first one, but the rotational crop following wheat was mungbean. Grain yield, biological yield and harvest index of rotational crops were analyzed. According to the result, when mungbean and maize were planted in rotation with wheat, residues of megaton and apyrus at 56 and 68 g/ha, had the most negative impacts on their yields. So that yield reduction were 37%, 24% and 21% in mungbean and 36%, 10% and 17% in maize, respectively. Therefore, it is needed to pay more attention to the response of rotational crops following wheat to residues of sulfonylurea herbicides in soil.

  14. Occurrence and estimation of pesticide residues in edible minor crops in southeastern Poland in 2013-2014.

    Science.gov (United States)

    Podbielska, Magdalena; Szpyrka, Ewa; Matyaszek, Aneta; Słowik-Borowiec, Magdalena; Rupar, Julian; Kurdziel, Anna

    2016-07-01

    This paper presents the results of official control of pesticide residues in minor crops collected in southeastern Poland in 2013-2014. Compliance of used pesticides with applicable law was also verified, and determined residues were compared to maximum residue levels (MRLs) provided for in Regulation (EC) No. 395/2005. A total of 583 samples of 25 different types of fresh fruit and vegetables were analyzed for pesticide residues. Pesticide residues were detected in 158 samples (27.1 % of the analyzed samples). According to the European Commission Health & Consumer Protection Directorate-General (SANCO) guidelines document, MRL violations were understood as cases where a residue level exceeded the MRL after the uncertainty of the method (50 %) was considered. MRL violations were found in four samples. The usage of unauthorized pesticides was detected in 5.8 % of analyzed samples. Substances banned in Poland were found in two samples. Fungicides were the most frequently detected group of pesticides. Pesticide residues were most commonly found in fruit samples (19.4 % of all analyzed samples), mainly in gooseberry, redcurrant, and huckleberry. The majority of samples were compliant with MRLs, which means that they were suitable for trade.

  15. Characterization of aluminium-based water treatment residual for potential phosphorus removal in engineered wetlands

    OpenAIRE

    Babatunde, A.O.; Zhao, Y.Q.; Burke, A. M.; Morris, M. A.; HANRAHAN, J.P.

    2009-01-01

    Aluminium-based water treatment residual (Al-WTR) is the most widely generated residual from water treatment facilities worldwide. It is regarded as a by-product of no reuse potential and landfilled. This study assessed Al-WTR as a potential phosphate-removing substrate in engineered wetlands for wastewater treatment. Results indicate the specific surface area ranged from 28.0 m2 g-1 to 41.4 m2 g-1 and this increased with increasing particle size. X-ray Diffraction (XRD), Fourier transform in...

  16. Algal derivatives may protect crops from residual soil salinity: a case study on a tomato-wheat rotation

    Science.gov (United States)

    Di Stasio, Emilio; Raimondi, Giampaolo; Van Oosten, Michael; Maggio, Albino

    2017-04-01

    In coastal areas, summer crops are frequently irrigated with saline water. As a consequence, salts may accumulate in the root zone with detrimental effects on the following winter crops if the rainfall is insufficient to leach them. Two field experiments were performed in 2015-2016 on a field used for tomato (summer) wheat (winter) rotation cropping. The spring-summer experiment was carried in order to evaluate the effect of two algal derivatives (Ascophyllum nodosum), Rygex and Super Fifty, on a tomato crop exposed to increasing salinity and reduced nutrient availability. In the autumn-winter experiment we investigated the effect of residual salts from the previous summer irrigations on plant growth and yield of wheat treated with the same two algal extracts. The salt treatment for the irrigated summer crop was 80 mM NaCl plus a non-salinized control. The nutrient regimes were 100% and 50% of the tomato nutritional requirements. With both the seaweeds applications the salt stressed plants were demonstrated improved Relative Water Content and water potential. Nevertheless the total fresh biomass and the fruit fresh weight were enhanced only in the non salinized controls. Application of algal derivatives increased the total fresh weight over controls in the non salinized plants. The seaweed treatments enhanced the fruit fresh weight with an increase of 30% and 46% for Rygex and Super Fifty, respectively. Preliminary analysis of the ion profile in roots, shoots and leaves, indicates that the seaweed extracts may enhance the assimilation of ions in fruits affecting their nutritional value. The residual salinity of the summer experiment reduced the wheat biomass production. However, the seaweed extracts treatments improved growth under salinity. In the salt stressed plants the Super Fifty application increased shoots and ears by 34% and 23% respectively, compared to the non treated plants. Plant height was increased by application of seaweeds extracts for both the

  17. Bias in IPCC Methodologies for Assessment of N2O emissions from Crop Residue

    Science.gov (United States)

    Nitrogen use efficiencies are difficult to measure and reported recoveries from fertilizer N by crops average =50%. Worldwide studies (20+) conducted with precise 15N techniques that trace the fate of N found that an average of 66% of the fertilizer was recovered in crops and soils. In other words,...

  18. Aggregate-associated carbon and nitrogen affected by residue placement, crop species, and nitrogen fertilization

    Science.gov (United States)

    High variability in soil and climatic conditions results in limited changes in soil aggregate-21 associated C and N levels as affected by management practices during a crop growing season in 22 the field. We evaluated the effects of crop species (spring wheat [Triticum aestivum L.], pea 23 [Pisum sa...

  19. Treatment methods and comparative risks of thorium removal from waste residues

    Energy Technology Data Exchange (ETDEWEB)

    Porter, R.D.; Hamby, D.M.; Martin, J.E.

    1997-07-01

    This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE`s Formerly Utilized Sites Remedial Action Program (FUSRAP). Removal of {sup 230}Th from uranium process residues would significantly reduce the buildup of {sup 226}Ra (half-life of 1600 years), and since {sup 230}Th concentrations at most of the important sites greatly exceed the {sup 226}Ra concentrations, such removal would reduce the accumulation of additional radiation risks associated with {sup 226}Ra and its products; and, if treatment also removed {sup 226}Ra, these risks could be mitigated even further. Removal of {sup 232}Th from thorium process residues would remove the source material for {sup 228}Ra, and since {sup 228}Ra has a half-life of 5.76 years, its control at FUSRAP sites could be done with land use controls for the 30--50 years required for {sup 228}Ra and the risks associated with its decay products to decay away. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation.

  20. Synergistic analyses of optical and microphysical properties of agricultural crop residue burning aerosols over the Indo-Gangetic Basin (IGB)

    Science.gov (United States)

    Mishra, Amit Kumar; Shibata, Takashi

    2012-09-01

    Agriculture crop residue burning is one of the important sources of trace gas emissions and aerosol loading over the Indo-Gangetic Basin (IGB). The present study deals with the spatial variability including the vertical structure of optical and microphysical properties of aerosols, during the crop residue burning season (October and November) of 2009 over the IGB. Increased number of fire counts observed by MODIS (MODerate resolution Imaging Spectroradiometer) that is associated with high aerosol optical depth (MODIS-AOD > 0.7) and enhanced tropospheric columnar NO2 concentrations observed by OMI (Ozone Monitoring Instrument), suggests agriculture crop residue burning as a main source of aerosol loading over the IGB during October and November. PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a Lidar) observations show an increase in fine mode AOD (at 865 nm) from October (0.1-0.2) to November (0.2-0.3) over the IGB, which is well corroborated with MODIS observations. CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) data shows the elevated aerosol plume (4.0-4.5 km) over the north-west IGB (associated with burning activities) that could have been caused by positive buoyancy through pyro-convection. However, large concentrations of aerosol were found below 1.0 km altitude. The averaged vertical structure of crop residue burning aerosols shows an exponential decrease with altitude (mean scale height ˜1.44 ± 0.20 km). Aerosol optical and microphysical properties coupled with backward air trajectories analyses at Kanpur indicated regional transport of biomass burning aerosols in a downwind direction from north-west IGB to south-east IGB. Aerosol classification, using AERONET (AErosol RObotic NETwork)-derived absorption properties coupled with size parameter (2006-2010) showed clear seasonal dependency of aerosol types which revealed the presence of biomass burning aerosols only during the crop

  1. Physical and hydraulic properties of aridisols as affected by nutrient and crop-residue management in a cotton-wheat system - doi: 10.4025/actasciagron.v35i1.14683

    Directory of Open Access Journals (Sweden)

    Muhammad Mahmood-ul-Hassan

    2012-08-01

    Full Text Available A 5-year cotton–wheat rotation field experiment was conducted on two alkaline-calcareous soils to investigate the impact of integrated nutrient-management and crop-residue incorporation on soil physical and hydrological properties. The nutrient treatments were: T1–farmers' fertilizer use; T2–balanced nutrient management (recommended N, P, Zn. and B from mineral sources; T3–integrated nutrient management, same as T2, except that 75% N was applied from fertilizer and 25% as FYM; and T4 same as T2, except that every alternate year, wheat was substituted by Berseem green manure. All treatments were compared with and without crop residue incorporation. Soil organic matter (SOM content in both the soils was significantly increased with T2, T3 and T4 as compared with T1, and was increased further where the nutrient-management treatments were applied in combination with crop-residue recycling. Higher increase in SOM content was observed in soil having relatively lower initial SOM (0.61% than soil having initial 0.80% SOM content. Increased SOM content, in return, decreased soil bulk density, improved macro- and meso-porosity, and enhanced percent recovery of stable aggregates correspondingly. Infiltration rates were 20, 49 and 26% higher with T2, T3 and T4, respectively, over T1 and 64% higher with crop-residue incorporation over crop-residue removal. Positive impacts on soil physical properties were also observed in the sub-soil layers.

  2. Grain yield and crop N offtake in response to residual fertilizer N in long-term field experiments

    DEFF Research Database (Denmark)

    Petersen, Jens; Thomsen, Ingrid Kaag; Mattsson, L.

    2010-01-01

    Organic inputs [e.g. animal manure (AM) and plant residues] contribute directly to the soil organic N pool, whereas mineral N fertilizer contributes indirectly by increasing the return of the crop residues and by microbial immobilization. To evaluate the residual effect of N treatments established...... in four long-term (>35 yr) field experiments, we measured the response of barley (grain yield and N offtake at crop maturity) to six rates (0, 30, 60, 90, 120 and 150 kg N/ha) of mineral fertilizer N (Nnew) applied in subplots replacing the customary long-term plot treatments of fertilizer inputs (Nprev......). Rates of Nprev above 50-100 kg N/ha had no consistent effect on the soil N content, but this was up to 20% greater than that in unfertilized treatments. Long-term unfertilized plots should not be used as control to test the residual value of N in modern agriculture with large production potentials...

  3. Unavailability of the residual system heat removal of Angra 1 by Bayesian networks considering dependent failures

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Many R.S.; Melo, Paulo F.F.F. e, E-mail: mgomes@con.ufrj.br, E-mail: frutuoso@nuclear.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Programa de Pos-Graduacao em Engenharia Nuclear

    2015-07-01

    This work models by Bayesian networks the residual heat removal system (SRCR) of Angra I nuclear power plant, using fault tree mapping for systematically identifying all possible modes of occurrence caused by a large loss of coolant accident (large LOCA). The focus is on dependent events, such as the bridge system structure of the residual heat removal system and the occurrence of common-cause failures. We used the Netica™ tool kit, Norsys Software Corporation and Python 2.7.5 for modeling Bayesian networks and Microsoft Excel for modeling fault trees. Working with dependent events using Bayesian networks is similar to the solutions proposed by other models, beyond simple understanding and ease of application and modification throughout the analysis. The results obtained for the unavailability of the system were satisfactory, showing that in most cases the system will be available to mitigate the effects of an accident as described above. (author)

  4. Exposed inferior alveolar neurovascular bundle during surgical removal of a residual cyst.

    Science.gov (United States)

    Boffano, Paolo; Gallesio, Cesare

    2010-01-01

    Iatrogenic neurodeficiency is one of the most distressing complications to any surgical procedure. The prediction of close proximity of the oral lesions to the inferior alveolar neurovascular bundle is extremely important. Furthermore, iatrogenic neurosensory dysfunctions of the facial region involve important medicolegal issues. In this report, we describe the case of a patient who did not show either paresthesia or anesthesia after the surgical removal of a mandibular residual cyst that exhibited adherence to the inferior alveolar nerve bundle.

  5. Assessment of ASME code examinations on regenerative, letdown and residual heat removal heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Gosselin, Stephen R.; Cumblidge, Stephen E.; Anderson, Michael T.; Simonen, Fredric A.; Tinsley, G. A.; Lydell, B.; Doctor, Steven R.

    2005-07-01

    Inservice inspection requirements for pressure retaining welds in the regenerative, letdown, and residual heat removal heat exchangers are prescribed in Section XI Articles IWB and IWC of the ASME Boiler and Pressure Vessel Code. Accordingly, volumetric and/or surface examinations are performed on heat exchanger shell, head, nozzle-to-head, and nozzle-to-shell welds. Inspection difficulties associated with the implementation of these Code-required examinations have forced operating nuclear power plants to seek relief from the U.S. Nuclear Regulatory Commission. The nature of these relief requests are generally concerned with metallurgical, geometry, accessibility, and radiation burden. Over 60% of licensee requests to the NRC identify significant radiation exposure burden as the principle reason for relief from the ASME Code examinations on regenerative heat exchangers. For the residual heat removal heat exchangers, 90% of the relief requests are associated with geometry and accessibility concerns. Pacific Northwest National Laboratory was funded by the NRC Office of Nuclear Regulatory Research to review current practice with regard to volumetric and/or surface examinations of shell welds of letdown heat exchangers regenerative heat exchangers and residual (decay) heat removal heat exchangers Design, operating, common preventative maintenance practices, and potential degradation mechanisms are reviewed. A detailed survey of domestic and international PWR-specific operating experience was performed to identify pressure boundary failures (or lack of failures) in each heat exchanger type and NSSS design. The service data survey was based on the PIPExp® database and covers PWR plants worldwide for the period 1970-2004. Finally a risk assessment of the current ASME Code inspection requirements for residual heat removal, letdown, and regenerative heat exchangers is performed. The results are then reviewed to discuss the examinations relative to plant safety and

  6. Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent

    Energy Technology Data Exchange (ETDEWEB)

    Chen Baoliang, E-mail: blchen@zju.edu.cn [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Yuan Miaoxin; Liu Hao [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Zhejiang University, Hangzhou, Zhejiang 310028 (China)

    2011-04-15

    Graphical abstract: The structure-effect relationship provides a reference to select and modify plant residues as a biosorbent with high efficiency to tackle organic pollutants. Research highlights: {yields} Polycyclic aromatic hydrocarbons are effectively removed by plant residues. {yields} Biosorption mechanism of plant residues to abate PAHs is a partitioning process. {yields} Partition coefficients are negatively related with sugar contents of biosorbent. {yields} The aromatic component and K{sub ow} exhibit positive effects on biosorption. {yields} The structure-effect relationship guides plant residue using as a biosorbent. - Abstract: To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N{sub 2} surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (K{sub d}) followed the order of PN > BL > OP > RR > WC, ranged from 2484 {+-} 24.24 to 5306 {+-} 92.49 L/kg. Except the WC sample, the K{sub d} values were negatively correlated with sugar content, polar index [(N + O)/C] of the biosorbents, while the aromatic component exhibited positive effects. For a given biosorbent of bamboo leaves, the carbon-normalized partition coefficients (K{sub oc}) were linearly correlated with octanol-water partition coefficients (K{sub ow}) of PAHs, i.e., log K{sub oc} = 1.16 log K{sub ow} - 1.21. The structure-effect relationship provides a reference to select and modify plant residues as a

  7. Respiratory health concerns in children at some strategic locations from high PM levels during crop residue burning episodes

    Science.gov (United States)

    Gupta, Sachin; Agarwal, Ravinder; Mittal, Susheel K.

    2016-07-01

    Particulate Matter (PM) levels in the ambient air of three urban sites of strategic importance in Punjab (second largest agricultural state of India) were monitored from September 2013 to June 2014 covering two seasons of crop residue burning episodes of rice and wheat, respectively. During both crop periods, the levels varied from 71 to 167 μgm-3(PM10) and 43-107 μgm-3 (PM2.5), which were observed to be much beyond the permissible limits of 100 μgm-3 for PM10 and 60 μgm-3 for PM2.5 set by state pollution control agencies. Simultaneously, Pulmonary Function Test (PFT) parameters of children (age group 10-16 years) residing at these sites were monitored. PFT parameters like Forced Vital Capacity (FVC) and Peak Expiratory Flow (PEF) were monitored on 50 healthy subjects at each site. The results indicated an alarming fall in FVC (5%-7%) and in PEF (4%-6%) parameters during the crop residue burning period's .The decrement was almost same for all age groups of children. The adverse effect was more on female subjects than male subjects. The impact of particulate matter pollution was more prominent in industrially important site (7%, SIS) as compared to historically (3%, HIS) and commercially (4%, CAS) important sites.

  8. Potential use of edible crops in the phytoremediation of endosulfan residues in soil.

    Science.gov (United States)

    Mitton, Francesca M; Gonzalez, Mariana; Monserrat, José M; Miglioranza, Karina S B

    2016-04-01

    Endosulfan is a persistent and toxic organochlorine pesticide of banned or restricted use in several countries. It has been found in soil, water, and air and is bioaccumulated and magnified in ecosystems. Phytoremediation is a technology that promises effective and inexpensive cleanup of contaminated hazardous sites. The potential use of tomato, sunflower, soybean and alfalfa species to remove endosulfan from soil was investigated. All species were seeded and grown in endosulfan-spiked soils (8000 ng g(-1) dry weight) for 15 and 60 days. The phytoremediation potential was evaluated by studying the endosulfan levels and distribution in the soil-plant system, including the evaluation of soil dehydrogenase activity and toxic effects on plants. Plant endosulfan uptake leads to lower insecticide levels in the rhizosphere with regards to bulk soil or near root soil at 15 days of growth. Furthermore, plant growth-induced physical-chemical changes in soil were evidenced by differences in soil dehydrogenase activity and endosulfan metabolism. Sunflower showed differences in the uptake and distribution of endosulfan with regard to the other species, with a distribution pesticide pattern of aerial tissues > roots at 15 days of growth. Moreover, at 60 days, sunflower presented the highest pesticide levels in roots and leaves along with the highest phytoextraction capacity. Lipid peroxidation levels correlated positively with endosulfan accumulation, reflecting the negative effect of this insecticide on plant tissues. Considering biomass production and accumulation potential, in conjunction with the reduction of soil pesticide levels, sunflower plants seem to be the best phytoremediation candidate for endosulfan residues in soils.

  9. Modified Layer-Removal Method for Measurement of Residual Stress in Pre-stretched Aluminium Alloy Plate

    Institute of Scientific and Technical Information of China (English)

    Liangbao Liu; Jianfei Sun; Wuyi Chen; Pengfei Sun

    2015-01-01

    Residual stress is one of the factors affecting the machining deformation of monolithic structure parts in the aviation industry. Thus, the studies on machining deformation rules induced by residual stresses largely depend on correctly and efficiently measuring the residual stresses of workpieces. A modified layer⁃removal method is proposed to measure residual stress by analysing the characteristics of a traditional layer⁃removal method. The coefficients of strain release are then deduced according to the simulation results using the finite element method ( FEM) . Moreover, the residual stress in a 7075T651 aluminium alloy plate is measured using the proposed method, and the results are then analyzed and compared with the data obtained by the traditional methods. The analysis indicates that the modified layer⁃removal method is effective and practical for measuring the residual stress distribution in pre⁃stretched aluminium alloy plates.

  10. Effects of tillage and crop residue management on soil respiration and its mechanism%耕作方式与秸秆还田对土壤呼吸的影响及机理

    Institute of Scientific and Technical Information of China (English)

    赵亚丽; 薛志伟; 郭海斌; 穆心愿; 李潮海

    2014-01-01

    In Huang-Huai-Hai area in China, winter wheat (Triticum aestivum)/summer maize (Zea mays) rotation is the dominant two-crop-per-year cropping system. Crop residue removal and subsoil compaction have become limiting factors for yield improvement in the area. Tillage and crop residue retained are two effective ways to improve soil properties and increase crop yield. Soil tillage and crop residue retained can reduce soil bulk density, improve water storage and aeration in the soil, increase soil microorganism and enzyme activities, improve soil biological properties, thus promote plant root growth and increase crop production. However, studies in the past mainly focused on the effects of single tillage or single crop residue retained on soil respiration. There is a need currently for research in the effects of tillage, crop residue retained and their interaction on soil respiration under the two-crop-per-year cropping system. A two-year field study from 2010 to 2012 was conducted to determine effects of tillage practice and crop residue management on soil respiration, soil temperature, soil water content, soil compaction, soil organic carbon content, dry matter accumulation of plant and root in the wheat-corn double crop cropping system. The study was conducted at the Wen County Experimental Station, Henan, China. The experiment was arranged in a split-plot design with three replications. Tillage practice and crop residue management were two factors of interest. The tillage treatment was randomly assigned to main plots and crop residue treatment was randomly assigned to sub-plots. The tillage practice treatments were: moldboard plough (MP) to a maximum depth of 15 cm, deep moldboard plough (DMP) to a maximum depth of 30 cm, and chisel plough (CP) to a maximum depth of 30 cm. All three tillage treatments were implemented after corn harvested in October of 2010 and 2011. In addition to different plough treatments, all plots were disc harrowed before wheat planting

  11. Estimation of lifetime of carbonaceous aerosol from open crop residue burning during Mount Tai Experiment 2006 (MTX2006

    Directory of Open Access Journals (Sweden)

    X. L. Pan

    2012-06-01

    Full Text Available Studying the emission ratios of carbonaceous aerosols (element carbon, EC, and organic carbon, OC from open biomass burning helps to reduce uncertainties in emission inventories and provides necessary constraints for model simulations. We measured apparent elemental carbon (ECa and OC concentrations at the summit of Mount Tai (Mt. Tai during intensive open crop residue burning (OCRB episodes using a Sunset OCEC analyzer. Equivalent black carbon (BCe concentrations were determined using a Multiple Angle Absorption Photometer (MAAP. In the fine particle mode, OC and EC showed strong correlations (r > 0.9 with carbon monoxide (CO. Footprint analysis using the FLEXPART_WRF model indicated that OCRB in central east China (CEC had a significant influence on ambient carbonaceous aerosol loadings at the summit of Mt. Tai. ΔECa/ΔCO ratios resulting from OCRB plumes were 14.3 ± 1.0 ng m−3 ppbv−1 at Mt. Tai. This ratio was more than three times those resulting from urban pollution in CEC, demonstrating that significant concentrations of soot particles were released from OCRB. ΔOC/ΔCO ratio from fresh OCRB plumes was found to be 41.9 ± 2.6 ng m−3 ppbv−1 in PM1. The transport time of smoke particles was estimated using the FLEXPART_WRF tracer model by releasing inert particles from the ground layer inside geographical regions where large numbers of hotspots were detected by a MODIS satellite sensor. Fitting regressions using the e-folding exponential function indicated that the removal efficiency of OC (normalized to CO was much larger than that of ECa mass, with mean lifetimes of 27 h (1.1 days for OC and 105 h (4.3 days for ECa, respectively. The lifetime of black carbon estimated for the OCRB events in east China was comparably lower than the values normally adopted in the transport models. Short lifetime of organic carbon

  12. Estimation of lifetime of carbonaceous aerosol from open crop residue burning during Mount Tai Experiment 2006 (MTX2006)

    Science.gov (United States)

    Pan, X. L.; Kanaya, Y.; Wang, Z. F.; Komazaki, Y.; Taketani, F.; Akimoto, H.; Pochanart, P.; Liu, Y.

    2012-06-01

    Studying the emission ratios of carbonaceous aerosols (element carbon, EC, and organic carbon, OC) from open biomass burning helps to reduce uncertainties in emission inventories and provides necessary constraints for model simulations. We measured apparent elemental carbon (ECa) and OC concentrations at the summit of Mount Tai (Mt. Tai) during intensive open crop residue burning (OCRB) episodes using a Sunset OCEC analyzer. Equivalent black carbon (BCe) concentrations were determined using a Multiple Angle Absorption Photometer (MAAP). In the fine particle mode, OC and EC showed strong correlations (r > 0.9) with carbon monoxide (CO). Footprint analysis using the FLEXPART_WRF model indicated that OCRB in central east China (CEC) had a significant influence on ambient carbonaceous aerosol loadings at the summit of Mt. Tai. ΔECa/ΔCO ratios resulting from OCRB plumes were 14.3 ± 1.0 ng m-3 ppbv-1 at Mt. Tai. This ratio was more than three times those resulting from urban pollution in CEC, demonstrating that significant concentrations of soot particles were released from OCRB. ΔOC/ΔCO ratio from fresh OCRB plumes was found to be 41.9 ± 2.6 ng m-3 ppbv-1 in PM1. The transport time of smoke particles was estimated using the FLEXPART_WRF tracer model by releasing inert particles from the ground layer inside geographical regions where large numbers of hotspots were detected by a MODIS satellite sensor. Fitting regressions using the e-folding exponential function indicated that the removal efficiency of OC (normalized to CO) was much larger than that of ECa mass, with mean lifetimes of 27 h (1.1 days) for OC and 105 h (4.3 days) for ECa, respectively. The lifetime of black carbon estimated for the OCRB events in east China was comparably lower than the values normally adopted in the transport models. Short lifetime of organic carbon highlighted the vulnerability of OC to cloud scavenging in the presence of water-soluble organic species from biomass combustion.

  13. Bioenergy from crops and biomass residues: a consequential life-cycle assessment including land-use changes

    DEFF Research Database (Denmark)

    Tonini, Davide; Astrup, Thomas Fruergaard

    to represent the actual environmental impacts. This study quantified the GHG emissions associated with a number of scenarios involving bioenergy production (as combined-heat-and-power, heating, and transport biofuel) from energy crops, industrial/agricultural residues, algae, and the organic fraction...... demonstrated that algae represent an interesting alternative to terrestrial energy crops. This study provides GHG emission factors for a wide number of bioenergy scenarios. The aim is to inform decision/policy makers on the environmental consequences of producing biofuels from different sources......Biofuels are promising means to reduce fossil fuel depletion and mitigate greenhouse-gas (GHG) emissions. However, recent studies questioned the environmental benefits earlier attributed to biofuels, when these involve land-use changes (direct/indirect, i.e., dLUC/iLUC) (1-5). Yet, second...

  14. Enhanced formation of secondary air pollutants and aggravation of urban smog due to crop residue burning emissions in North India

    Science.gov (United States)

    Sarkar, Chinmoy; Kumar, Vinod; Sinha, Vinayak

    2013-04-01

    Biomass burning causes intense perturbations to regional atmospheric chemistry and air quality and is a significant global source of reactive pollutants to the atmosphere (Andreae and Merlet, 2001). In November 2012, large areas in North India including New Delhi experienced several weeks of aggravated smog and poor air quality due to the impact of crop residue burning, which is a biannual post harvest activity that occurs during Oct-Nov and April-May every year in the agricultural belts of North western India. In-situ high temporal resolution (1 measurement every minute) measurements of a suite of volatile organic compounds measured using proton transfer reaction mass spectrometry (PTR-MS) such as acetonitrile (biomass burning tracer) and aromatic hydrocarbons were performed simultaneously with carbon monoxide, nitrogen oxides, ozone and aerosol mass concentrations (PM 2.5 and PM 10) at a suburban site (30.667°N, 76.729°E and 310 m asl), impacted by air masses that had passed over the burning fields less than 72 hours ago. By using data from the same season but before the post harvest crop residue burning activity had commenced, we were able to quantify enhancements in ambient levels of the measured species due to the crop residue burning activity. When air masses influenced by the fire emissions reached the measurement site, peak values of about 8 ppbV acetonitrile, 4 ppmV CO, 100 ppbV NOx , 30 ppbV toluene and 15 ppbV benzene were observed which represented a factor of 2-5 increase over their ambient levels in the non-fire influenced period. Emission ratios of aromatic hydrocarbons/CO also showed a marked increase. Non fire event (N.F. E.) influenced and fire event (F.E.) influenced air masses had the following emission ratio enhancements: benzene/CO (N.F.E = 3; F.E. = 5), toluene/CO (N.F.E = 4; F.E. = 8.7) and sum of C8 aromatics/CO (N.F.E = 4; F.E. = 7.3) and sum of C9 aromatics/CO (N.F.E = 2.6; F.E. = 3.4). The OH reactivity of air masses which has strong

  15. Integrated waste management through producers and consumers education: composting of vegetable crop residues for reuse in cultivation.

    Science.gov (United States)

    Maniadakis, K; Lasaridi, K; Manios, Y; Kyriacou, M; Manios, T

    2004-01-01

    As part of the design of an integrated waste management scheme through the use of the PRECEDE/PROCEED model in the area of Crete, data concerning the applicability of composting in various agricultural wastes was considered as necessary. Vegetable residues from tomato, cucumber, eggplant, and pepper crops were collected, shredded and composted either alone or with the use of olive press cake, olive tree leaves, and branches and vine branches as bulking agents. Seven random combinations--mixtures of the above materials were composted using windrows, where additional four similar windrows were made up by approximately 10 m3 of the above mentioned vegetable crop residues. All windrows were turned four times during the eight weeks thermophylic phase, with the help of a mechanical turner. A large number of physiochemical parameters were monitored in the raw materials, at the end of the thermophylic phase and at the end of the maturation phase. The temperature which was monitored daily, recorded the highest values (above 55 degrees C) in the windrows where bulking agents were used. All raw vegetable crop residues and their mixtures presented increased electrical conductivity values (above 5 mS/cm and up to 9.7 mS/cm) resulting to end products with respectively high EC values (above 3 mS/cm and up to 15 mS/cm) probably due to the presence of large amounts of soil, rich in fertilisers, attached to the roots of the plants. There was no detection of any remains of the 13 pesticides for which all 11 composts were tested for. The accuracy of the results was tested through a recovery test of the pesticides in mature compost, resulting to acceptable recovery values.

  16. Effects of crop sanitation on banana weevil, Cosmopolites sordidus (Germar) (Coleoptera : Curculionidae), populations and crop damage in Uganda

    NARCIS (Netherlands)

    Masanza, M.; Gold, C.S.; Huis, van A.; Ragama, P.E.

    2006-01-01

    Crop sanitation, i.e. destruction of crop residues, has been hypothesized to lower banana weevil damage by removing adult refuges and breeding sites. Although it has been widely recommended to farmers, limited data are available to demonstrate the efficacy of this method. The effects of crop sanitat

  17. Long Term Sugarcane Crop Residue Retention Offers Limited Potential to Reduce Nitrogen Fertilizer Rates in Australian Wet Tropical Environments.

    Science.gov (United States)

    Meier, Elizabeth A; Thorburn, Peter J

    2016-01-01

    The warming of world climate systems is driving interest in the mitigation of greenhouse gas (GHG) emissions. In the agricultural sector, practices that mitigate GHG emissions include those that (1) reduce emissions [e.g., those that reduce nitrous oxide (N2O) emissions by avoiding excess nitrogen (N) fertilizer application], and (2) increase soil organic carbon (SOC) stocks (e.g., by retaining instead of burning crop residues). Sugarcane is a globally important crop that can have substantial inputs of N fertilizer and which produces large amounts of crop residues ('trash'). Management of N fertilizer and trash affects soil carbon and nitrogen cycling, and hence GHG emissions. Trash has historically been burned at harvest, but increasingly is being retained on the soil surface as a 'trash blanket' in many countries. The potential for trash retention to alter N fertilizer requirements and sequester SOC was investigated in this study. The APSIM model was calibrated with data from field and laboratory studies of trash decomposition in the wet tropics of northern Australia. APSIM was then validated against four independent data sets, before simulating location × soil × fertilizer × trash management scenarios. Soil carbon increased in trash blanketed soils relative to SOC in soils with burnt trash. However, further increases in SOC for the study region may be limited because the SOC in trash blanketed soils could be approaching equilibrium; future GHG mitigation efforts in this region should therefore focus on N fertilizer management. Simulated N fertilizer rates were able to be reduced from conventional rates regardless of trash management, because of low yield potential in the wet tropics. For crops subjected to continuous trash blanketing, there was substantial immobilization of N in decomposing trash so conventional N fertilizer rates were required for up to 24 years after trash blanketing commenced. After this period, there was potential to reduce N fertilizer

  18. Activated carbon for the removal of pharmaceutical residues from treated wastewater.

    Science.gov (United States)

    Ek, Mats; Baresel, Christian; Magnér, Jörgen; Bergström, Rune; Harding, Mila

    2014-01-01

    Pharmaceutical residues, which pass naturally through the human body into sewage, are in many cases virtually unaffected by conventional wastewater treatment. Accumulated in the environment, however, they can significantly impact aquatic life. The present study indicates that many pharmaceutical residues found in wastewater can be removed with activated carbon in a cost-efficient system that delivers higher resource utilisation and security than other carbon systems. The experiment revealed a substantial separation of the analysed compounds, notwithstanding their relatively high solubility in water and dissimilar chemical structures. This implies that beds of activated carbon may be a competitive alternative to treatment with ozone. The effluent water used for the tests, performed over 20 months, originated from Stockholm's largest sewage treatment plant. Passing through a number of different filters with activated carbon removed 90-98% of the pharmaceutical residues from the water. This paper describes pilot-scale tests performed by IVL and the implications for an actual treatment plant that has to treat up to several thousand litres of wastewater per second. In addition, the advantages, disadvantages and costs of the method are discussed. This includes, for example, the clogging of carbon filters and the associated hydraulic capacity limits of the activated carbon.

  19. Nitrogen mineralization and denitrification as influenced by crop residue particle size

    DEFF Research Database (Denmark)

    Ambus, P.; Jensen, E.S.

    1997-01-01

    for the two pea treatments. In suspensions denitrification was similar for the two treatments both with barley and pea residue. We conclude that the higher microbial activity associated with the initial decomposition of ground plant material is due to a more intimate plant residue-soil contact. On the long...

  20. Preparation of Three-Dimensional Chitosan-Graphene Oxide Aerogel for Residue Oil Removal.

    Science.gov (United States)

    Guo, Xiaoqing; Qu, Lijun; Zhu, Shifeng; Tian, Mingwei; Zhang, Xiansheng; Sun, Kaikai; Tang, Xiaoning

    2016-08-01

    Graphene oxide has been used as an adsorbent in wastewater treatment. However, the hydrophily and dispersibility in aqueous solution limit its practical application in environmental protection. In this paper, a novel, environmentally friendly adsorbent, chitosan and chitosan-graphene oxide aerogels with a diverse shape, large specific surface area, and unique porous structure were prepared by a freeze-drying method. The structure of the adsorbents was investigated using scanning electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffraction (XRD); the specific surface area and swelling capability were also characterized. In addition, removal of diesel oil from seawater by chitosan aerogel (CSAG) and chitosan-graphene oxide aerogel (AGGO-1 and AGGO-2) was studied and batch adsorption experiments were carried out as a function of different adsorbent dosages (0-6 g), contact time (0-120 minutes), pH (3-9), and initial concentrations of oil residue (3-30 g/L) to determine the optimum condition for the adsorption of residue oil from seawater. The results showed that the chitosan-graphene oxide aerogels were more effective to remove diesel oil from seawater compared with pure chitosan aerogel. A removal efficiency ≥ 95% of the chitosan-graphene oxide aerogels could be achieved easily at the initial concentrations of 20 g/L, which indicated that the chitosan-graphene oxide aerogels can be used to treat the industrial oil leakage or effluent in the natural water.

  1. Evaluation of one-step micro polishers for residual resin removal after debonding on fluorosed teeth

    Directory of Open Access Journals (Sweden)

    Padmalatha Challa

    2014-01-01

    Full Text Available Aim and objectives: To evaluate the effectiveness of one step micro polishers for residual resin removal on fluorosed teeth using scanning electron microscope (SEM. Methods and Material: 55 teeth with mild to moderate fluorosis were selected with five teeth as control. Metal brackets were bonded onto 50 teeth which were divided into 5 groups. The finishing and polishing methods which were tested include tungsten carbide burs (TCB, multistep finishing system (Sof-Lex, one step polishers (PoGo and combination of TCB with multistep and one step polishing systems. After resin removal, all the samples were examined under SEM for assessment of the enamel surface. Results: The enamel surface was closest to untouched enamel in samples finished with the PoGo one step polishers followed by Sof-Lex multistep finishing system. However, they took the longest time to finish. TCB required the shortest time for residual resin removal. Conclusions: All polishing systems produce a certain degree of damage to the enamel surface with the smoothest surface being produced by one step polishers on fluorosed teeth.

  2. Removing chlorine of CuCl residue from zinc hydrometallurgy by microwave roasting

    Institute of Scientific and Technical Information of China (English)

    卢帅丹; 夏仡; 黄昌元; 吴国钦; 彭金辉; 巨少华; 张利波

    2014-01-01

    Most Zn hydrometallurgy factories adopt Cu2SO4 as a dechlorination reagent from zinc solution nowadays, thus much CuCl residue is produced. The existing process of treating this residue is washing with water or sodium carbonate solution, which would cause a lot of troubles to water treatment and waste discharge. A method of microwave roasting was adopted for dechlorination of CuCl residue. A 1.5 kW microwave roasting equipment with dust collection and tail gas adsorption systems was set up and applied during the experiment. By investigating the effect of temperature, heat preservation time, moisture content of raw material and grain size of samples on the dechlorination, the optimal experimental condition is obtained. When the samples with 2%moisture and <150 μm grain size are microwave roasted at 400 °C for 2 h, the Cl content turns from 14.27% to 1.35% and the dechlorination rate is as high as 90%, while that with conventional heating is only 60%-80%. The phase change of the roasting process investigated with X-ray diffraction verifies that CuCl in CuCl residue is removed by being transformed into CuO.

  3. SEM Analysis of Residual Dentin Surface in Primary Teeth Using Different Chemomechanical Caries Removal Agents.

    Science.gov (United States)

    Thakur, Rachna; Patil, Sandya Devi S; Kush, Anil; Madhu, K

    The purpose of this in vitro study was to analyze the residual dentinal surfaces following caries removal using two chemomechanical methods (Papacarie Duo and Carie Care), by scanning electron microscopy (SEM). Twenty extracted primary molars with active occlusal carious lesions were randomly assigned two groups depending on the CMCR agent used for the caries excavation - Group 1 - with Papacarie Duo and Group - 2 with Carie Care. After the caries excavation, the specimens were subjected to SEM analysis. Though both the agents showed the minimal smear layer with the patent dentinal tubules, Carie care showed patent dentinal tubules with a clearly exposed peritubular and intertubular collagen network. Carie Care treated surface exhibited better surface morphology of residual dentin.

  4. Tillage and crop residue effects on rainfed wheat and maize production in Nortern China

    NARCIS (Netherlands)

    Wang Xiaobin,; Wu Huijin,; Dai Kuai,; Zhang Dingchen,; Feng Donghui,; Zhao Quansheng,; Wu Xueping,; Jin Ke,; Cai Diangxiong,; Oenema, O.; Hoogmoed, W.B.

    2012-01-01

    Dryland farming in the dry semi-humid regions of northern China is dominated by mono-cropping systems with mainly maize (Zea mays L.) or wheat (Triticum aestivum), constrained by low and variable rainfall, and by improper management practices. Addressing these problems, field studies on tillage and

  5. Removal of copper in leachate from mining residues using electrochemical technology.

    Science.gov (United States)

    Lambert, Andréa; Drogui, Patrick; Daghrir, Rimeh; Zaviska, François; Benzaazoua, Mostafa

    2014-01-15

    This research is related to a laboratory study on the performance of a successive mining residues leaching and electrochemical copper recovery process. To clearly define the experimental region for response surface methodology (RSM), a preliminary study was performed by applying a current intensity varying from 0.5 A to 4.0 A for 60 min. By decreasing the current intensity from 4.0 A to 0.5 A, a good adhesion and a very smooth and continuous interface of copper was formed and deposited on the cathode electrode. However, the removal rate of Cu decreased from 83.7% to 37.9% when the current intensity passed from 4.0 A to 0.5 A, respectively. Subsequently, the factorial design and central composite design methodologies were successively employed to define the optimal operating conditions for copper removal in the mining residues leachate. Using a 2(3) factorial matrix, the best performance for copper removal (97.7%) was obtained at a current intensity of 2.0 A during 100 min. The current intensity and electrolysis time were found to be the most influent parameters. The contribution of current intensity and electrolysis time was around 65.8% and 33.9%, respectively. The treatment using copper electrode and current intensity of 1.3 A during 80 min was found to be the optimal conditions in terms of cost/effectiveness. Under these conditions, 86% of copper can be recovered for a total cost of 0.56 $ per cubic meter of treated mining residues leachate.

  6. Reliability analysis on passive residual heat removal of AP1000 based on Grey model

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Shi; Zhou, Tao; Shahzad, Muhammad Ali; Li, Yu [North China Electric Power Univ., Beijing (China). School of Nuclear Science and Engineering; Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy, Beijing (China); Jiang, Guangming [Nuclear Power Institute of China, Chengdu (China). Science and Technology on Reactor System Design Technology Laboratory

    2017-06-15

    It is common to base the design of passive systems on the natural laws of physics, such as gravity, heat conduction, inertia. For AP1000, a generation-III reactor, such systems have an inherent safety associated with them due to the simplicity of their structures. However, there is a fairly large amount of uncertainty in the operating conditions of these passive safety systems. In some cases, a small deviation in the design or operating conditions can affect the function of the system. The reliability of the passive residual heat removal is analysed.

  7. Failure Modes and Effects Analysis (FMEA) of the Residual Heat Removal System. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, F T

    1976-01-01

    The Residual Heat Removal System (RHRS) transfer heat from the Reactor Coolant System (RCS) to the reactor plant Component Cooling System (CCS) to reduce the temperature of the RCS at a controlled rate during the second part of normal plant cooldown and maintains the desired temperature until the plant is restarted. By the use of an analytic tool, the Failure Modes and Effects Analysis, it is shown that the RHRS, because of its redundant two train design, is able to accommodate any credible component single failure with the only effect being an extension in the required cooldown time, thus demonstrating the reliability of the RHRS to perform its intended function.

  8. Sustainable Activated Carbons from Agricultural Residues Dedicated to Antibiotic Removal by Adsorption

    Institute of Scientific and Technical Information of China (English)

    Jonatan Torres-Perez; Claire Gerente; Yves Andres

    2012-01-01

    The. objectives.of this study are to convert at laboratory s.cale agric.ultural residues into activated carbons (AC) with specific properties, to characterize them and to test them in adsorption reactor for tetracycline removal, a common antibiotic. Two new ACs were produced by direct activation with steam from beet pulp (BP-H2O) and peanut hu_lls (PH-H2O) in environmental friendly conditions BP-H2O and PH-H2Opresentcarbon content rangedcarbons with different intrinsic properties.

  9. Experimental Research on Passive Residual Heat Removal System of Chinese Advanced PWR

    Directory of Open Access Journals (Sweden)

    Zhuo Wenbin

    2014-01-01

    Full Text Available Passive residual heat removal system (PRHRS for the secondary loop is one of the important features for Chinese advance pressurized water reactor (CAPWR. To prove the safety characteristics of CAPWR, serials of experiments have been done on special designed PRHRS test facility in the former stage. The test facility was built up following the scaling laws to preserve the similarity to CAPWR. A total of more than 300 tests have been performed on the test facility, including 90% steady state cases and 10% transient cases. A semiempirical model was generated for passive heat removal functions based on the experimental results of steady state cases. The dynamic capability characteristics and reliability of passive safety system for CAPWR were evidently proved by transient cases. A new simulation code, MISAP2.0, has been developed and calibrated by experimental results. It will be applied in future design evaluation and optimization works.

  10. High-resolution historical emission inventories of crop residue burning in fields in China for the period 1990-2013

    Science.gov (United States)

    Li, Jing; Li, Yaqi; Bo, Yu; Xie, Shaodong

    2016-08-01

    High-resolution historical emission inventories of crop residue burning in fields in China were developed for the period 1990-2013. More accurate time-varying statistical data and locally observed emission factors were utilized to estimate crop residue open burning emissions at provincial level. Then pollutants emissions were allocated to a high spatial resolution of 10 km × 10 km and a high temporal resolution of 1 day based on the Moderate Resolution Imaging Spectroradiometer (MODIS) Fire Product (MOD/MYD14A1). Results show that China's CO emissions have increased by 5.67 times at an annual average rate of 24% from 1.06 Tg in 1990 to 7.06 Tg in 2013; the emissions of CO2, CH4, NMVOCs, N2O, NOx, NH3, SO2, PM2.5, OC, and BC have increased by 595%, 500%, 608%, 584%, 600%, 600%, 543%, 571%, 775%, and 500%, respectively, over the past 24 years. Spatially, the regions with high emissions had been notable expanding over the years, especially in the central eastern districts, the Northeastern of China, and the Sichuan Basin. Strong temporal pattern were observed with the highest emissions in June, followed by March to May and October. This work provides a better understanding of the spatiotemporal representation of agricultural fire emissions in China and can benefit both air quality modeling and management with improved accuracy.

  11. Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste.

    Science.gov (United States)

    Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A P; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye; Li, Weijun

    2017-07-11

    Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combustion released OM and S-rich particles. Interestingly, particles from hardwood (pear wood and bamboo) and softwood (cypress and pine wood) combustion were mainly soot and OM in the flaming phase, respectively. The combustion of foam boxes, rubber tires, and plastic bottles/bags in the flaming phase released large amounts of soot internally mixed with a small amount of OM, whereas the combustion of printed circuit boards and copper-core cables emitted large amounts of OM with Br-rich inclusions. In addition, the printed circuit board combustion released toxic metals containing Pb, Zn, Sn, and Sb. The results are important to document properties of primary particles from combustion sources, which can be used to trace the sources of ambient particles and to know their potential impacts in human health and radiative forcing in the air.

  12. Dataset: Soil erosion and organic matter for central Great Plains cropping systems under residue removal

    Science.gov (United States)

    The diversity of geo-climatic land bases and potential feedstocks within the United States Central Great Plains (CGP) requires sustainable production that provides optimal resource utilization while maintaining or enhancing localized soil and environmental quality as much as possible. This study exa...

  13. [Water treatment residual as a bioretention media amendment for phosphorus removal].

    Science.gov (United States)

    Wang, Jian-Jun; Li, Tian; Zhang, Ying

    2014-12-01

    The characteristics of phosphorus adsorption of both soil and water treatment residual (WTR) were investigated through batch tests. The removal of phosphorus in runoff by bioretention column was evaluated. Furthermore, the feasibility of taking the WTR as a bioretention amendment was discussed. The results indicated that the phosphorus adsorptive capacity of WTR was significantly higher than that of soil. With a high influent phosphorus concentrations (1.0 mg x L(-1)), the columns with amended media showed a better long-term removal efficiency than the columns with traditional media. The concentrations of TP in effluent from columns with amended media were less than 0.050 mg x L(-1) after 7 months' continuous operation. According to batch test results, it was estimated that the phosphorus adsorptive capacity of amended media, which was mixed with 4% of WTR, was 4 times as high as the traditional media under same conditions. Adsorption and precipitation by amorphous iron and aluminum is the main mechanism for phosphorus removal in amended media. It is recommended that the mixture with 4% - 5% of WTR by mass in media would improve the phosphorus removal of bioretention in engineering practice.

  14. The removal of dinitrochlorobenzene from industrial residuals by liquid-liquid extraction with chemical reaction

    Directory of Open Access Journals (Sweden)

    G. C. M. Ferreira

    2007-09-01

    Full Text Available Nitrochlorobenzenes (NCBs are very important in the chemical industry since they have been used as raw material for the manufacture of crop protection products, as active ingredients in the pharmaceutical industry, as pigments and as antioxidants as well as for other uses. In industrial processes, NCBs are produced by monochlorobenzene (MCB nitration reactions and one of the main residuals formed is dinitrochlorobenzene (DNCB, which is mainly composed of the isomer 2,4DNCB. This subproduct, although of commercial interest when in its pure state, is generally incinerated due to the high costs of recovery treatment and purification. The objective of this study is to present an alternative to the treatment of industrial residuals containing DNCB. The technique consists of converting DNCB into sodium dinitrophenolate, which is very soluble in water and is also easy to reuse. For this purpose, liquid-liquid extraction with chemical reaction (alkaline hydrolysis with a rotating disc contactor (RDC is used. Experimental data on MCB nitration reactions as well as alkaline hydrolysis using a rotating disc contactor are presented.

  15. Reuse of acid coagulant-recovered drinking waterworks sludge residual to remove phosphorus from wastewater

    Science.gov (United States)

    Yang, Lan; Wei, Jie; Zhang, Yumei; Wang, Jianli; Wang, Dongtian

    2014-06-01

    Acid coagulant-recovered drinking waterworks sludge residual (DWSR) is a waste product from drinking waterworks sludge (DWS) treatment with acid for coagulant recovery. In this study, we evaluated DWSR as a potential phosphorus (P) removing material in wastewater treatment by conducting a series of batch and semi-continuous tests. Batch tests were carried out to study the effects of pH, initial concentration, and sludge dose on P removal. Batch test results showed that the P removal efficiency of DWSR was highly dependent on pH. Calcinated DWSR (C-DWSR) performed better in P removal than DWSR due to its higher pH. At an optimum initial pH value of 5-6 and a sludge dose of 10 g/L, the P removal rates of DWSR and DWS decreased from 99% and 93% to 84% and 14%, respectively, and the specific P uptake of DWSR and DWS increased from 0.19 and 0.19 mg P/g to 33.60 and 5.72 mg P/g, respectively, when the initial concentration was increased from 2 to 400 mg/L. The effective minimum sludge doses of DWSR and DWS were 0.5 g/L and 10 g/L, respectively, when the P removal rates of 90% were obtained at an initial concentration of 10 mg/L. Results from semi-continuous test indicated that P removal rates over 99% were quickly achieved for both synthetic and actual wastewater (lake water and domestic sewage). These rates could be maintained over a certain time under a certain operational conditions including sludge dose, feed flow, and initial concentration. The physicochemical properties analysis results showed that the contents of aluminum (Al) and iron (Fe) in DWSR were reduced by 50% and 70%, respectively, compared with DWS. The insoluble Al and Fe hydroxide in DWS converted into soluble Al and Fe in DWSR. Metal leaching test results revealed that little soluble Al and Fe remained in effluent when DWSR was used for P removal. We deduced that chemical precipitation might be the major action for P removal by DWSR and that adsorption played only a marginal role.

  16. BAGGING TECHNIQUE: WATER CATCHMENT SYSTEM FOR RESIDUAL MOISTURE CROPS USED BY PRODUCERS MASIACA, SONORA

    Directory of Open Access Journals (Sweden)

    Pastor Sánchez-García

    2015-07-01

    Full Text Available In the southeast of Sonora as in most of the State, land is unproductive due to its arid and semi-arid land, if it does not have small or large irrigation facilities. Where economic conditions are reduced, producers need to develop techniques that help to overcome the erraticity in the availability of water, especially for irrigation. That's why Mays Indian and Masiaca community private producers from Sonora have developed a technique for harvesting from water of avenues of the intermittent streams near their plots, and once the ground has the adequate humidity conditions they can establish crops of their interest, so it is possible to obtain acceptable harvest in corn, peas, sorghum and safflower. However, these producers face a series of problems related primarily to the lack of rain; lack of credit support for the construction or maintenance of the required facilities; lack of profitability of crops established there, the abandonment of agricultural land, erosion of knowledge, etc. The analysis of this study can draw the following conclusions: The bagging technique is feasible if there are heavy rains, with the presence of cyclones, in October; the acceptable harvest obtained in established crops is largely due to the contribution of organic matter derived from the Avenues; the organizational levels observed are simple and operational.

  17. Numerical Analysis of Flow Phenomena in a Residual Heat Removal Pump

    Directory of Open Access Journals (Sweden)

    Jianping Yuan

    2015-02-01

    Full Text Available The hydraulic performances as well as the cavitation phenomena in a scaled residual heat removal pump were investigated by experimental and numerical methods, respectively. In particular, a 3D numerical model of cavitation was adopted to simulate the internal cavitating flow through the model pump. The hydraulic performances of the model pump predicted by numerical simulations were in good agreement with the corresponding experimental data. The main generation and evolution of attached cavitation throughout the blade channels at different cavitating conditions have been investigated using the vapor fraction ISO surface and in-plane velocity vectors. Results show that the low static pressure at the impeller inlet is the main reason for leading edge cavitation by correlation analysis of static pressure on the midspan of impeller. Cavitation proved to occur over a wide range of flow rates, producing a characteristic creeping shape of the head-drop curve and developing in the form of nonaxisymmetric cavities at design flow rate. Moreover, the occurrence of these cavities, attached to the suction surface of blades, was found to depend on the NPSHA value. Numerical and experimental results in this paper can provide better understanding of the origin of leading edge cavitation in residual heat removal pumps.

  18. Enhanced Cleaning of Genesis Solar Wind Sample 61348 for Film Residue Removal

    Science.gov (United States)

    Allums, K. K.; Gonzalez, C. P.; Kuhlman, K. R.; Allton, J. H.

    2015-01-01

    The Genesis mission returned to Earth on September 8, 2004, experiencing a nonnominal reentry. During the recovery of the collector materials from the capsule, many of the collector fragments were placed on the adhesive protion of post-it notes to prevent the fragments from moving during transport back to Johnson Space Center. This unknowingly provided an additional contaminate that would prove difficult to remove with the limited chemistries allowed in the Genesis Curation Laboratory. Generally when collector material samples are prepared for allocation to PIs, the samples are cleaned front side only with Ultra-Pure Water (UPW) via megasonic dispersion to the collector surface to remove crash debris and contamination. While this cleaning method works well on samples that were not placed on post-its during recovery, it has caused movement of the residue on the back of the sample to be deposited on the front in at least two examples. Therefore, samples placed on the adhesive portion on post-it note, require enhanced cleaning methods since post-it residue has proved resistant to UPW cleaning.

  19. Procedure of Active Residual Heat Removal after Emergency Shutdown of High-Temperature-Gas-Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available After emergency shutdown of high-temperature-gas-cooled reactor, the residual heat of the reactor core should be removed. As the natural circulation process spends too long period of time to be utilized, an active residual heat removal procedure is needed, which makes use of steam generator and start-up loop. During this procedure, the structure of steam generator may suffer cold/heat shock because of the sudden load of coolant or hot helium at the first few minutes. Transient analysis was carried out based on a one-dimensional mathematical model for steam generator and steam pipe of start-up loop to achieve safety and reliability. The results show that steam generator should be discharged and precooled; otherwise, boiling will arise and introduce a cold shock to the boiling tubes and tube sheet when coolant began to circulate prior to the helium. Additionally, in avoiding heat shock caused by the sudden load of helium, the helium circulation should be restricted to start with an extreme low flow rate; meanwhile, the coolant of steam generator (water should have flow rate as large as possible. Finally, a four-step procedure with precooling process of steam generator was recommended; sensitive study for the main parameters was conducted.

  20. Engineered biochar from biofuel residue: characterization and its silver removal potential.

    Science.gov (United States)

    Yao, Ying; Gao, Bin; Wu, Feng; Zhang, Cunzhong; Yang, Liuyan

    2015-05-20

    A novel approach was used to prepare engineered biochar from biofuel residue (stillage from bagasse ethanol production) through slow pyrolysis. The obtained biochar was characterized for its physicochemical properties as well as silver sorption ability. Sorption experimental data showed that engineered biochar quickly and efficiently removed silver ion (Ag(+)) from aqueous solutions with a Langmuir maximum capacity of 90.06 mg/g. The high sorption of Ag(+) onto the biochar was attributed to both reduction and surface adsorption mechanisms. The reduction of Ag(+) by the biochar was confirmed with scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the postsorption biochar, which clearly showed the presence of metallic silver nanoparticles on the surface of the carbon matrix. An antimicrobial ability test indicated that silver-laden biochar effectively inhibited the growth of Escherichia coli, while the original biochar without silver nanoparticles promoted growth. Thus, biochar, prepared from biofuel residue materials, could be potentially applied not only to remove Ag(+) from aqueous solutions but also to produce a new value-added nanocomposite with antibacterial ability.

  1. The effectiveness of sewage treatment processes to remove faecal pathogens and antibiotic residues

    Science.gov (United States)

    Hendricks, Rahzia; Pool, Edmund John

    2012-01-01

    Pathogens and antibiotics enter the aquatic environment via sewage effluents and may pose a health risk to wild life and humans. The aim of this study was to determine the levels of faecal bacteria, and selected antibiotic residues in raw wastewater and treated sewage effluents from three different sewage treatment plants in the Western Cape, South Africa. Sewage treatment plant 1 and 2 use older technologies, while sewage treatment plant 3 has been upgraded and membrane technologies were incorporated in the treatment processes. Coliforms and Escherichia coli (E. coli) were used as bioindicators for faecal bacteria. A chromogenic test was used to screen for coliforms and E. coli. Fluoroquinolones and sulfamethoxazole are commonly used antibiotics and were selected to monitor the efficiency of sewage treatment processes for antibiotic removal. Enzyme Linked Immunosorbent Assays (ELISAs) were used to quantitate antibiotic residues in raw and treated sewage. Raw intake water at all treatment plants contained total coliforms and E. coli. High removal of E. coli by treatment processes was evident for treatment plant 2 and 3 only. Fluoroquinolones and sulfamethoxazole were detected in raw wastewater from all sewage treatment plants. Treatment processes at plant 1 did not reduce the fluoroquinolone concentration in treated sewage effluents. Treatment processes at plant 2 and 3 reduced the fluoroquinolone concentration by 21% and 31%, respectively. Treatment processes at plant 1 did not reduce the sulfamethoxazole concentration in treated sewage effluents. Treatment processes at plant 2 and 3 reduced sulfamethoxazole by 34% and 56%, respectively. This study showed that bacteria and antibiotic residues are still discharged into the environment. Further research needs to be undertaken to improve sewage treatment technologies, thereby producing a better quality treated sewage effluent. PMID:22242882

  2. Evaluation of dry technology for removal of pellicle adhesive residue on advanced optical reticles

    Science.gov (United States)

    Paracha, Shazad; Bekka, Samy; Eynon, Benjamin; Choi, Jaehyuck; Balooch, Mehdi; Varghese, Ivin; Hopkins, Tyler

    2013-09-01

    The fast pace of MOSFET scaling is accelerating the introduction of smaller technology nodes to extend CMOS beyond 20nm as required by Moore's law. To meet these stringent requirements, the industry is seeing an increase in the number of critical layers per reticle set as it move to lower technology nodes especially in a high volume manufacturing operation. These requirements are resulting in reticles with higher feature densities, smaller feature sizes and highly complex Optical Proximity Correction (OPC), built with using new absorber and pellicle materials. These rapid changes are leaving a gap in maintaining these reticles in a fab environment, for not only haze control but also the functionality of the reticle. The industry standard of using wet techniques (which uses aggressive chemicals, like SPM, and SC1) to repel reticles can result in damage to the sub-resolution assist features (SRAF's), create changes to CD uniformity and have potential for creating defects that require other means of removal or repair. Also, these wet cleaning methods in the fab environment can create source for haze growth. Haze can be controlled by: 1) Chemical free (dry) reticle cleaning, 2) In-line reticle inspection in fab, and 3) Manage the environment where reticles are stored. In this paper we will discuss a dry technique (chemical free) to remove pellicle adhesive residue from advanced optical reticles. Samsung Austin Semiconductors (SAS), jointly worked with Eco-Snow System (a division of RAVE N.P., Inc.) to evaluate the use of Dry Reactive Gas (DRG) technique to remove pellicle adhesive residue on reticles. This technique can significantly reduce the impact to the critical geometry in active array of the reticle, resulting in preserving the reticle performance level seen at wafer level. The paper will discuss results on the viability of this technique used on advanced reticles.

  3. A combined process of adsorption and Fenton-like oxidation for furfural removal using zero-valent iron residue.

    Science.gov (United States)

    Li, Furong; Bao, Jianguo; Zhang, Tian C; Lei, Yutian

    2015-01-01

    In this study, the feasibility of using a combined adsorption and Fenton-like oxidation process (with zero-valent iron (ZVI) residue from heat wraps as an absorbent and catalyst) to remove furfural in the solution was evaluated. The influencing parameters (e.g. pH, H2O2 concentration, initial furfural concentration) and the reusability of ZVI residue (to replace the iron powder) were estimated. The ZVI residue was found to have much better adsorption effect on furfural at pH 2.0 compared with pH 6.7. For Fenton-like reaction alone with ZVI residue, the highest furfural removal of 97.5% was observed at the concentration of 0.176 mol/L H2O2, and all of the samples had >80% removal efficiency at different initial furfural concentrations of 2, 10, 20, 30 and 40 mmol/L. However, with a combined adsorption and Fenton-like oxidation, the removal efficiency of furfural was nearly 100% for all treatments. The ZVI residue used for furfural removal was much better than that of iron powder in the Fenton-like reaction at a seven-cycle experiment. This study suggests the combined process of adsorption and Fenton-like oxidation using ZVI residue is effective for the treatment of furfural in the liquid.

  4. Nitrous oxide emissions and controls as influenced by tillage and crop residue management strategy

    DEFF Research Database (Denmark)

    Mutegi, James; Munkholm, Lars Juhl; Petersen, Bjørn Molt

    2010-01-01

    management, N2O emissions from DD and RT plots never exceeded emissions from CT plots. Retention of residue was estimated to reduce emissions from DD plots by 39% and in RT plots by 9%, but to increase N2O emissions from the CT plots by 35%. Relative soil gas diffusivity (Rdiff), soil NO3-N, soil temperature...

  5. Square baler field test under different sugar cane crop residue conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Arthur Miola de; Ripoli, Tomaz Caetano Cannavan; Gadanha Junior, Casimiro [Escola Superior de Agricultura Luiz de Queiroz (ESALQ-USP), Piracicaba (Brazil). Dept. de Engenharia Rural], E-mail: ammello@esalq.usp.br; Ripoli, Marco Lorezzo Cunali [John Deere, Ribeirao Preto, SP (Brazil)

    2008-07-01

    The energy demand increase of the country allows the sugar cane business sector to be a major player in production and commercialization areas of electric energy using cogeneration powered by bagasse and sugar cane residues. The objective of the study was to evaluate some of the performance parameters of an Express 5040 baler, brand Nogueira, used to collect residues. The tests were conducted in a sugar cane mechanized harvest area. The baler was submitted to three different conditions of residues windrowing: 'in natura', under single and double raking operations. For all treatments soil sampling analyzes were done to find out ground homogeneity conditions were the test took place. The simple raking operation offered better conditions for the machine: Effective Capacity of 8.21 t.{sup h}-{sup 1} and 0.88 ha.h{sup -1}; average bale weight of 22.33 kg (SD=3.58, CV=16.01 %); costs of 7.45 R$.t{sup -1} of baled residue; 0.17 R$.fardo{sup -1} and 69.47 R$.ha{sup -1}. (author)

  6. Adsorptive removal of residual catalyst from palm biodiesel: Application of response surface methodology

    Directory of Open Access Journals (Sweden)

    Mjalli Sabri Farouq

    2012-01-01

    Full Text Available In this work, the residual potassium hydroxide catalyst was removed from palm oil-based methyl esters using an adsorption technique. The produced biodiesel was initially purified through a water washing process. To produce a biodiesel with a better quality and also to meet standard specifications (EN 14214 and ASTM D6751, batch adsorption on palm shell activated carbon was used for further catalyst removal. The Central Composite Design (CCD of the Response Surface Methodology (RSM was used to study the influence of adsorbent amount, time and temperature on the adsorption of potassium species. The maximum catalyst removal was achieved at 40°C using 0.9 g activated carbon for 20 h adsorption time. The results from the Response Surface Methodology are in a good agreement with the measured values. The absolute error in prediction at the optimum condition was 3.7%, which is reasonably accurate. This study proves that adsorption post-treatment techniques can be successfully employed to improve the quality of biodiesel fuel for its effective use on diesel engines and to minimize the usage of water.

  7. Optimizing production of hydroxyapatite from alkaline residue for removal of Pb2+ from wastewater

    Science.gov (United States)

    Yan, Yubo; Wang, YanPeng; Sun, Xiuyun; Li, Jiansheng; Shen, Jinyou; Han, Weiqing; Liu, Xiaodong; Wang, Lianjun

    2014-10-01

    Alkaline residue, a common solid waste generated from the ammonia-soda process for the production of soda ash, has been converted into hydroxyapatite for Pb2+ removal from wastewater. Response surface methodology was used to optimize the preparation conditions which were Ca/P (molar ratio), reaction temperature and reaction time, with the Pb2+ removal percentage as targeted response. The optimum conditions were identified to be Ca/P of 1.29, reaction temperature of 165.87 °C and reaction time of 14.5 h. Batch tests were conducted to evaluate the adsorption performance of optimum adsorbent (O-HAP), and the adsorption data were analyzed with different kinetic and isotherm models. The results showed that the pseudo-second order kinetic model and Langmuir isotherm model could best describe the adsorption of Pb2+ on O-HAP. The maximum adsorption capacity calculated from Langmuir equation was 1429 mg/g, which was greater than other familiar adsorbents. The MINTEQ results predicted that the formation of different Pb precipitates was the main mechanism in Pb2+ removal process, which was in good agreement with the kinetic and thermodynamic studies and were confirmed by the SEM-EDS and XRD analysis. In addition to aqueous medium, the O-HAP also could efficiently immobilize Pb2+ from contaminated soil.

  8. Barriers and drivers towards the incorporation of crop residue in the soil. Analysis of Italian farmers’ opinion with the theory of planned behaviour

    Directory of Open Access Journals (Sweden)

    Luca Bechini

    2015-12-01

    Full Text Available Despite the benefits arising from incorporating crop residue in the soil, some farmers decide to burn or sell it. The objective of the work described in this paper was to quantify the adoption of crop residue incorporation by Italian farmers, and to identify the barriers and drivers that they perceive towards this agricultural management practice. We applied a behavioural approach, based on the theory of planned behaviour. In agriculture, this theory can be used to study individual farmer beliefs to understand the intention to adopt agricultural management practices. Based on preliminary semi-structured interviews with 24 farmers, we have prepared and disseminated a structured questionnaire in dairy farms in the plain of northern Italy, in arable farms in the plain of northern, central, and southern Italy, and in arable farms in the hill of central and southern Italy. The questionnaire contained questions to reveal subjective beliefs of the farmers on the outcomes of incorporating crop residue, and on the referents and control factors that might influence adoption. We have received 315 filled questionnaires from 16 regions and 54 provinces. The survey has identified major drivers and barriers towards the incorporation of crop residue in the soil. The main drivers were the expected improvement of soil quality (higher soil organic matter, improved structure and fertility, the expected increase of grain protein concentration in the following wheat crop, the availability of adequate machinery, the prohibition of burning crop residue, and the knowledge that incorporation is important (which emphasizes the importance of an effective advisory service. The main barriers were the costs of incorporation, the need to increase the use of nitrogen fertiliser when straw is incorporated, and the problems to sow the following crop in the presence of residue. While on the basis of the preliminary interviews we expected that the possibility to sell the straw and

  9. Mitigation of methane and nitrous oxide emissions from flood-irrigated rice by no incorporation of winter crop residues into the soil

    Directory of Open Access Journals (Sweden)

    Tiago Zschornack

    2011-04-01

    Full Text Available Winter cover crops are sources of C and N in flooded rice production systems, but very little is known about the effect of crop residue management and quality on soil methane (CH4 and nitrous oxide (N2O emissions. This study was conducted in pots in a greenhouse to evaluate the influence of crop residue management (incorporated into the soil or left on the soil surface and the type of cover-crop residues (ryegrass and serradella on CH4 and N2O emissions from a flooded Albaqualf soil cultivated with rice (Oryza sativa L.. The closed chamber technique was used for air sampling and the CH4 and N2O concentrations were analyzed by gas chromatography. Soil solution was sampled at two soil depths (2 and 20 cm, simultaneously to air sampling, and the contents of dissolved organic C (DOC, NO3-, NH4+, Mn2+, and Fe2+ were analyzed. Methane and N2O emissions from the soil where crop residues had been left on the surface were lower than from soil with incorporated residues. The type of crop residue had no effect on the CH4 emissions, while higher N2O emissions were observed from serradella (leguminous than from ryegrass, but only when the residues were left on the soil surface. The more intense soil reduction verified in the deeper soil layer (20 cm, as evidenced by higher contents of reduced metal species (Mn2+ and Fe2+, and the close relationship between CH4 emission and the DOC contents in the deeper layer indicated that the sub-surface layer was the main CH4 source of the flooded soil with incorporated crop residues. The adoption of management strategies in which crop residues are left on the soil surface is crucial to minimize soil CH4 and N2O emissions from irrigated rice fields. In these production systems, CH4 accounts for more than 90 % of the partial global warming potential (CH4+N2O and, thus, should be the main focus of research.

  10. Removal of element mercury by medicine residue derived biochars in presence of various gas compositions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guoliang [School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Shen, Boxiong, E-mail: shenbx@nankai.edu.cn [School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401 (China); College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Li, Yongwang [College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Zhao, Bin [School of Chemical Engineering, Hebei University of Technology, Tianjin 300401 (China); Wang, Fumei; He, Chuan; Wang, Yinyin; Zhang, Min [College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2015-11-15

    Highlights: • Both physisorption and chemisorption of Hg{sup 0} occurred on the surface of M6WN5. • Chemisorption process was an absolute predominant route for Hg{sup 0} removal by M6WN5. • The effect of NO, H{sub 2}O, SO{sub 2} and O{sub 2} on Hg{sup 0} removal by M6WN5 was investigated. • M6WN5 demonstrated to be a promising Hg{sup 0} sorbent in flue gas. - Abstract: Pyrolyzed biochars from an industrial medicinal residue waste were modified by microwave activation and NH{sub 4}Cl impregnation. Mercury adsorption of different modified biochars was investigated in a quartz fixed-bed reactor. The results indicated that both physisorption and chemisorption of Hg{sup 0} occurred on the surface of M6WN5 which was modified both microwave and 5 wt.% NH{sub 4}Cl loading, and exothermic chemisorption process was a dominant route for Hg{sup 0} removal. Microwave activation improved pore properties and NH{sub 4}Cl impregnation introduced good active sites for biochars. The presence of NO and O{sub 2} increased Hg{sup 0} adsorption whereas H{sub 2}O inhibited Hg{sup 0} adsorption greatly. A converse effect of SO{sub 2} was observed on Hg{sup 0} removal, namely, low concentration of SO{sub 2} promoted Hg{sup 0} removal obviously whereas high concentration of SO{sub 2} suppressed Hg{sup 0} removal. The Hg{sup 0} removal by M6WN5 was mainly due to the reaction of the C−Cl with Hg{sup 0} to form HgCl{sub 2}, and the active state of C−Cl{sup *} groups might be an intermediate group in this process. Thermodynamic analysis showed that mercury adsorption by the biochars was exothermic process and apparent adsorption energy was 43.3 kJ/mol in the range of chemisorption. In spite of low specific surface area, M6WN5 proved to be a promising Hg{sup 0} sorbent in flue gas when compared with other sorbents.

  11. Determination of mesotrione residues and metabolites in crops, soil, and water by liquid chromatography with fluorescence detection.

    Science.gov (United States)

    Alferness, Philip; Wiebe, Lawrence

    2002-07-03

    A method for the determination of residues of mesotrione and two metabolites in a variety of environmental matrixes has been developed. Mesotrione, a new selective herbicide for use in corn, is 2-(4-methylsulfonyl-2-nitrobenzoyl)-1,3-cyclohexanedione. The metabolite 4-methylsulfonyl-2-nitrobenzoic acid (MNBA) is determined with the parent compound in crops, whereas two metabolites, 2-amino-4-methylsulfonyl-benzoic acid (AMBA) and MNBA are determined with parent in soil and water. Crop samples are macerated with an acetonitrile/water mixture, and an aliquot is evaporated and acidified then centrifuged. Soil is shaken with an ammonium hydroxide solution, and an aliquot is acidified then centrifuged. For water analysis, an aliquot is acidified. Crop and soil extracts, and water, are cleaned up using reverse-phase high-performance liquid chromatography (RPHPLC) with mesotrione and MNBA isolated using a fraction collector. During this clean up, AMBA is determined in soil and water samples using fluorescence detection. The collected mesotrione and MNBA fractions are converted into AMBA via oxidation followed by reduction in the case of mesotrione, or by reduction alone in the case of MNBA. Both fractions are analyzed by RPHPLC with fluorescence detection using an AMBA external reference standard. The method was tested on corn grain, fodder, and forage, as well as on sugar cane. The limits of quantitation (LOQ) for each analyte are 0.01 mg/kg for crops, 0.005 mg/kg for soil, and 0.10 microg/L for water. Method fortification recoveries from all crop commodities averaged 79% (CV = 7%, n = 37 and 82% (CV = 5%, n = 37) for mesotrione and MNBA, respectively. Soil was fortified at 0.005 and 0.05 mg/kg. Recoveries were 79% (CV = 4%, n = 12), 96% (CV = 2%, n = 12), and 89% (CV = 2%, n = 12) for mesotrione, MNBA, and AMBA, respectively. Groundwater, drinking water, seawater, and river water were fortified at 0.1 and 1.0 microg/L. Recoveries for all waters were 80% (CV = 7%, n = 51

  12. Nitrous Oxide Emission and Denitrifier Abundance in Two Agricultural Soils Amended with Crop Residues and Urea in the North China Plain

    Science.gov (United States)

    Jin, Haiyang; Liu, Yuan; Bai, Xueying; Ma, Dongyun; Zhu, Yunji; Wang, Chenyang; Guo, Tiancai

    2016-01-01

    The application of crop residues combined with Nitrogen (N) fertilizer has been broadly adopted in China. Crop residue amendments can provide readily available C and N, as well as other nutrients to agricultural soils, but also intensify the N fixation, further affecting N2O emissions. N2O pulses are obviously driven by rainfall, irrigation and fertilization. Fertilization before rainfall or followed by flooding irrigation is a general management practice for a wheat-maize rotation in the North China Plain. Yet, little is known on the impacts of crop residues combined with N fertilizer application on N2O emission under high soil moisture content. A laboratory incubation experiment was conducted to investigate the effects of two crop residue amendments (maize and wheat), individually or in combination with N fertilizer, on N2O emissions and denitrifier abundance in two main agricultural soils (one is an alluvial soil, pH 8.55, belongs to Ochri-Aquic Cambosols, OAC, the other is a lime concretion black soil, pH 6.61, belongs to Hapli-Aquic Vertosols, HAV) under 80% WFPS (the water filled pore space) in the North China Plain. Each type soil contains seven treatments: a control with no N fertilizer application (CK, N0), 200 kg N ha-1 (N200), 250 kg N ha-1 (N250), maize residue plus N200 (MN200), maize residue plus N250 (MN250), wheat residue plus N200 (WN200) and wheat residue plus N250 (WN250). Results showed that, in the HAV soil, MN250 and WN250 increased the cumulative N2O emissions by 60% and 30% compared with N250 treatment, respectively, but MN200 and WN200 decreased the cumulative N2O emissions by 20% and 50% compared with N200. In the OAC soil, compared with N200 or N250, WN200 and WN250 increased the cumulative N2O emission by 40%-50%, but MN200 and MN250 decreased the cumulative N2O emission by 10%-20%. Compared with CK, addition of crop residue or N fertilizer resulted in significant increases in N2O emissions in both soils. The cumulative N2O emissions

  13. Nitrous Oxide Emission and Denitrifier Abundance in Two Agricultural Soils Amended with Crop Residues and Urea in the North China Plain.

    Directory of Open Access Journals (Sweden)

    Jianmin Gao

    Full Text Available The application of crop residues combined with Nitrogen (N fertilizer has been broadly adopted in China. Crop residue amendments can provide readily available C and N, as well as other nutrients to agricultural soils, but also intensify the N fixation, further affecting N2O emissions. N2O pulses are obviously driven by rainfall, irrigation and fertilization. Fertilization before rainfall or followed by flooding irrigation is a general management practice for a wheat-maize rotation in the North China Plain. Yet, little is known on the impacts of crop residues combined with N fertilizer application on N2O emission under high soil moisture content. A laboratory incubation experiment was conducted to investigate the effects of two crop residue amendments (maize and wheat, individually or in combination with N fertilizer, on N2O emissions and denitrifier abundance in two main agricultural soils (one is an alluvial soil, pH 8.55, belongs to Ochri-Aquic Cambosols, OAC, the other is a lime concretion black soil, pH 6.61, belongs to Hapli-Aquic Vertosols, HAV under 80% WFPS (the water filled pore space in the North China Plain. Each type soil contains seven treatments: a control with no N fertilizer application (CK, N0, 200 kg N ha-1 (N200, 250 kg N ha-1 (N250, maize residue plus N200 (MN200, maize residue plus N250 (MN250, wheat residue plus N200 (WN200 and wheat residue plus N250 (WN250. Results showed that, in the HAV soil, MN250 and WN250 increased the cumulative N2O emissions by 60% and 30% compared with N250 treatment, respectively, but MN200 and WN200 decreased the cumulative N2O emissions by 20% and 50% compared with N200. In the OAC soil, compared with N200 or N250, WN200 and WN250 increased the cumulative N2O emission by 40%-50%, but MN200 and MN250 decreased the cumulative N2O emission by 10%-20%. Compared with CK, addition of crop residue or N fertilizer resulted in significant increases in N2O emissions in both soils. The cumulative N2O

  14. Earthworms and Plant Residues Modify Nematodes in Tropical Cropping Soils (Madagascar: A Mesocosm Experiment

    Directory of Open Access Journals (Sweden)

    Cécile Villenave

    2010-01-01

    Full Text Available Free-living nematodes present several characteristics that have led to their use as bioindicators of soil quality. Analyzing the structure of nematofauna is a pertinent way to understand soil biological processes. Earthworms play an important role in soil biological functioning and organic matter dynamics. Their effects on soil nematofauna have seldom been studied. We studied the effect of the tropical endogeic earthworm, Pontoscolex corethrurus, on nematode community structure in a 5-month field mesocosm experiment conducted in Madagascar. Ten different treatments with or without earthworms and with or without organic residues (rice, soybean were compared. Organic residues were applied on the soil surface or mixed with the soil. The abundance of nematodes (bacterial and fungal feeders was higher in presence of P. corethrurus than in their absence. The type of plant residues as well as their localisation had significant effects on the abundance and composition of soil nematodes. The analysis of nematode community structure showed that earthworm activity led to an overall activation of the microbial compartment without specific stimulation of the bacterial or fungal compartment.

  15. Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

    DEFF Research Database (Denmark)

    Mayer, J.; Buegger, F.; Jensen, E.S.

    2004-01-01

    C). A sandy loam soil for the experiment was either stored at 6 degreesC or planted with the respective grain legume in pots. Legumes were in situ N-15 stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition...

  16. Water Treatment Residuals and Scrap Tire Rubber as Green Sorbents for Removal of Stormwater Metals.

    Science.gov (United States)

    Deng, Yang; Morris, Ciapha; Rakshit, Sudipta; Landa, Edward; Punamiya, Pravin; Sarkar, Dibyendu

    2016-06-01

    Bench scale tests were performed to evaluate two recycled wastes, water treatment residuals (WTR) and scrap tire rubber (STR), for adsorption of selected metals from urban stormwater, and assess their release from used sorbents. Aluminum-WTR alone could rapidly and effectively remove Cu, Pb, and Zn, while STR alone continuously released Zn accompanied with Cu and Pb adsorption. Zn leaching from STR was significantly reduced in the presence of WTR. Very little metals released from used combined adsorbents in NaNO3 solution, and only part of them were extracted with EDTA (a strong chelating agent), suggesting that metal release is not a concern in a typical stormwater condition. A combination of WTR and STR is a new, effective method for mitigation of urban stormwater metals-WTR can inhibit the STR leaching, and STR improves the hydraulic permeability of WTR powders, a limiting factor for stormwater flow when WTR is used alone.

  17. Heat Transfer Analysis of Passive Residual Heat Removal Heat Exchanger under Natural Convection Condition in Tank

    Directory of Open Access Journals (Sweden)

    Qiming Men

    2014-01-01

    Full Text Available Aiming at the heat transfer calculation of the Passive Residual Heat Removal Heat Exchanger (PRHR HX, experiments on the heat transfer of C-shaped tube immerged in a water tank were performed. Comparisons of different correlation in literatures with the experimental data were carried out. It can be concluded that the Dittus-Boelter correlation provides a best-estimate fit with the experimental results. The average error is about 0.35%. For the tube outside, the McAdams correlations for both horizontal and vertical regions are best-estimated. The average errors are about 0.55% for horizontal region and about 3.28% for vertical region. The tank mixing characteristics were also investigated in present work. It can be concluded that the tank fluid rose gradually which leads to a thermal stratification phenomenon.

  18. ZnCl{sub 2}-activated biochar from biogas residue facilitates aqueous As(III) removal

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Dong; Tan, Fen; Zhang, Chuanpan [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005 (China); Jiang, Xiuli; Chen, Zheng; Li, Heng [Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen 361110 (China); Zheng, Yanmei [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005 (China); Li, Qingbiao [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005 (China); Environmental Science Research Center, College of the Environment & Ecology, Xiamen University, Xiamen 361110 (China); Wang, Yuanpeng, E-mail: wypp@xmu.edu.cn [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen 361005 (China)

    2016-07-30

    Highlights: • The ZnCl{sub 2}-activated biochar from the biogas residue of pig manure showed an excellent ability to remove As(III). • ZnCl{sub 2}-activated biochar had a large BET surface area and well-distributed pore structure. • Zinc played a dominant role in the removal of As(III) by forming Zn-O-As(III). - Abstract: Biochars prepared from biogas residue using different chemical activators were investigated for their As(III) adsorption properties. The results indicated that the original biochars did not exhibit significant As(III) adsorption. However, ZnCl{sub 2}-activated biochar, which possessed the largest specific surface area, 516.67 cm{sup 2}/g, and exhibited a perfectly porous texture, showed excellent performance in a 500 μgL{sup −1} solution of As(III). Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy were utilized to identify the mechanism of As(III) adsorption by ZnCl{sub 2}-activated biochar. Adsorption was found to occur mainly through ligand exchange of the hydroxyl in Zn-OH to form Zn-O-As(III), as well as through porous adsorption. As a low-cost adsorbent, the adsorption process was well fitted using a pseudo-second-order model, with an R{sup 2} > 0.993. The adsorption process was fast, requiring nearly 90 min to reach adsorption equilibrium. Batch adsorption experimental results indicated that ZnCl{sub 2}-activated biochar has a maximum adsorption capacity of 27.67 mg/g at pH 7.0, and the adsorption process followed the Freundlich isotherm model well, with an R{sup 2} > 0.994. In addition, the current work demonstrated the efficiency of using ZnCl{sub 2}-activated biochar adsorbent to treat As(III)-contaminated water.

  19. FEASIBILITY OF REMOVING FURFURALS FROM SUGAR SOLUTIONS USING ACTIVATED BIOCHARS MADE FROM AGRICULTURAL RESIDUES

    Directory of Open Access Journals (Sweden)

    Isabel Lima

    2011-06-01

    Full Text Available Lignocellulosic feedstocks are often prepared for ethanol fermentation by treatment with a dilute mineral acid catalyst that hydrolyzes the hemicellulose and possibly cellulose into soluble carbohydrates. The acid-catalyzed reaction scheme is sequential, whereby the released monosaccharides are further degraded to furans and other chemicals that are inhibitory to the subsequent fermentation step. This work tests the use of agricultural residues (e.g., plant waste as starting materials for making activated biochars to adsorb these degradation products. Results show that both furfural and hydroxymethylfurfural (HMF are adsorbed by phosphoric acid-activated and steam-activated biochars prepared from residues collected from cotton and linen production. Best results were obtained with steam-activated biochars. The activated biochars adsorbed about 14% (by weight of the furfurals at an equilibrium concentration of 0.5 g/L, and by adding 2.5% of char to a sugar solution, with either furfural or HMF (at 1 g/L, 99% of the furans were removed.

  20. Removal of Cu (II and Zn (II from water with natural adsorbents from cassava agroindustry residues

    Directory of Open Access Journals (Sweden)

    Daniel Schwantes

    2015-07-01

    Full Text Available Current study employs solid residues from the processing industry of the cassava (Manihot esculenta Crantz (bark, bagasse and bark + bagasse as natural adsorbents for the removal of metal ions Cu(II and Zn(II from contaminated water. The first stage comprised surface morphological characterization (SEM, determination of functional groups (IR, point of zero charge and the composition of naturally existent minerals in the biomass. Further, tests were carried out to evaluate the sorption process by kinetic, equilibrium and thermodynamic studies. The adsorbents showed a surface with favorable adsorption characteristics, with adsorption sites possibly derived from lignin, cellulose and hemicellulose. The dynamic equilibrium time for adsorption was 60 min. Results followed pseudo-second-order, Langmuir and Dubinin-Radushkevich models, suggesting a chemisorption monolayer. The thermodynamic parameters suggested that the biosorption process of Cu and Zn was endothermic, spontaneous or independent according to conditions. Results showed that the studied materials were potential biosorbents in the decontamination of water contaminated by Cu(II and Zn(II. Thus, the above practice complements the final stages of the cassava production chain of cassava, with a new disposal of solid residues from the cassava agroindustry activity.

  1. Removal of residual chlorine from Indiana 5 coal by supercritical carbon dioxide extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, B.S.; Azzam, F.O.; Lee, S. (University of Akron, Akron, OH (United States). Dept. of Chemical Engineering)

    1994-01-01

    The perchloroethylene coal desulfurization process has unique advantages as a precombustion coal cleaning process, that include high cleaning efficiencies, mild process conditions, minimal output of undesirable byproducts, and cost effectiveness. However, the use of perchloroethylene in the process renders an important process engineering problem of complete recovery and reuse of perchloroethylene, thus requiring a 'zero discharge' condition of the solvent. Therefore, the treated coal must be stripped of any residual perchloroethylene. Carbon dioxide (CO[sub 2]) in its supercritical state has been investigated for its ability to remove chlorine from Indiana 5 coal, that has been desulfurized by the perchloroethylene (PCE) process. The reduction of Cl content from a PCE treated and filtered coal has been as high as 78% by mass. The experiments have been carried out following a statistical experimental design and the discerning characteristics of the process have been identified. The solvent density and extraction conditions can be tailored in such a way as to optimally remove C from the coal without any detrimental effects on the coal matrix. The supercritical CO[sub 2] extraction process can be successfully implemented to the PCE coal cleaning process by replacing energy intensive steps of steam stripping and vacuum drying. 6 refs., 3 figs., 3 tabs.

  2. Assessment of the advantages of a residual heat removal system inside the reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, G.M.

    1995-12-31

    In the framework of research on diversified means for removing the residual heat from pressurized water reactors, the CEA is studying a passive system called RRP (Refroidissement du Reacteur au Primaire, or primary circuit cooling system), which includes integrated heat-exchangers and a layout of the internal structures so as to obtain convection from the primary circuit inside the vessel, whatever the state of the loops. This system is operational for all primary circuit temperatures and pressures, as well as for a wide range of conditions: it is independent of the state of the loops, even if the volume of water in the primary circuit is small, it is compatible with either a passive or an active operation mode, and compatible with any other decay heat removal systems. An evaluation is presented here of the performance of the RRP system in the event of a small primary circuit break in a totally passive operation mode without the intervention of another system. The results of this evaluation show the interest of such a system: a clear increase of the time-delay for the implementation of a low pressure safety injection system, no need for the use of a high pressure safety injection system. (author). 4 refs., 7 figs., 1 tab.

  3. Strategy of Utilization of Locally Available Crop Residues and By-Products for Livestock Feeding in Tunisia

    Directory of Open Access Journals (Sweden)

    Moujahed-Raach, A.

    2000-01-01

    Full Text Available Important quantities of crop residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country but most of them are localized in the northern region. Some of the agricultural wastes are available in important quantities but are of nutritionally poor or moderate qualities (straw, olive wastes, poultry litter, etc, while others are produced in limited amounts but are of very interesting feeding values (sugar beet pulp, brewers grain, date residue, etc. The main applied strategies to valorize Tunisian agricultural by-products consist in ammoniation of cereal straws along with supplementation with multinutriment blocks and formulation of balanced diets based totally or partially on them. These alternatives are crucial in the improvement of feeding values of studied diets and animal performances essentially by improving micro-bial activity in the rumen. In Tunisia such solution could be applied both in extensive and moderate animal production systems.

  4. Strategy of Utilization of Locally Available Crop Residues and By-Products for Livestock Feeding in Tunisia

    Directory of Open Access Journals (Sweden)

    Moujahed-Raach, A.

    2001-01-01

    Full Text Available Important quantifies of crops residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country, but most of them are localised in the northern region. Some of the agricultural wastes are available in important quantifies but are of nutritionally poor or moderate qualifies (straw, olive wastes, poultry litter, etc, while others are produced in limited amounts but are of very interesting feeding values (sugar beet pulp, brewers grain, date residue, etc. The main applied strategies to valorise Tunisian agricultural by-products consist in ammoniation of cereal straws along with supplementation with multinutriment blocks and formulation of balanced diets based totally or partially on them. These alternatives are crucial in the improvement of feeding values of studied diets and animal performances essentially by improving microbial activity in the rumen. In Tunisia such solution could be applied both in extensive and moderate animal production systems.

  5. High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

    Directory of Open Access Journals (Sweden)

    Ileana Frasier

    2016-04-01

    Full Text Available The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina with rotation of sorghum (Sorghum bicolor in zero tillage alternating with rye (Secale cereale and vetch (Vicia villosa ssp. dasycarpa. Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC and community composition (DNA extraction, qPCR, and phospholipid FAME profiles were determined. Litter, aerial- and root biomass were collected and all material was analyzed for C and N. Results showed a rapid response of microbial biomass to a bacterial dominance independent of residue quality. Vetch had the highest diversity index, while the fertilized treatment had the lowest one. Vetch–sorghum rotation with high N mineralization rates and diverse microbial community sequestered more C and N in stable soil organic matter fractions than no-till sorghum alone or with rye, which had lower N turnover rates. These results reaffirm the importance of enhanced soil biodiversity for maintaining soil ecosystem functioning and services. The supply of high amounts of N-rich residues as provided by grass–legume cover crops could fulfill this objective.

  6. Optimizing production of hydroxyapatite from alkaline residue for removal of Pb{sup 2+} from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Yubo; Wang, YanPeng; Sun, Xiuyun, E-mail: sunxyun@njust.edu.cn; Li, Jiansheng; Shen, Jinyou; Han, Weiqing; Liu, Xiaodong; Wang, Lianjun, E-mail: wanglj@njust.edu.cn

    2014-10-30

    Highlights: • The solid waste from Soda Ash Plants was firstly converted into the high-efficiency adsorbent (O-HAP). • The response surface methodology was used to optimize the preparation conditions of O-HAP. • The O-HAP showed excellent immobilization ability for Pb{sup 2+} in both aqueous and soil medium. • The maximum adsorption capacity for Pb{sup 2+} (1429 mg/g) was considerably greater than other familiar adsorbents. - Abstract: Alkaline residue, a common solid waste generated from the ammonia-soda process for the production of soda ash, has been converted into hydroxyapatite for Pb{sup 2+} removal from wastewater. Response surface methodology was used to optimize the preparation conditions which were Ca/P (molar ratio), reaction temperature and reaction time, with the Pb{sup 2+} removal percentage as targeted response. The optimum conditions were identified to be Ca/P of 1.29, reaction temperature of 165.87 °C and reaction time of 14.5 h. Batch tests were conducted to evaluate the adsorption performance of optimum adsorbent (O-HAP), and the adsorption data were analyzed with different kinetic and isotherm models. The results showed that the pseudo-second order kinetic model and Langmuir isotherm model could best describe the adsorption of Pb{sup 2+} on O-HAP. The maximum adsorption capacity calculated from Langmuir equation was 1429 mg/g, which was greater than other familiar adsorbents. The MINTEQ results predicted that the formation of different Pb precipitates was the main mechanism in Pb{sup 2+} removal process, which was in good agreement with the kinetic and thermodynamic studies and were confirmed by the SEM-EDS and XRD analysis. In addition to aqueous medium, the O-HAP also could efficiently immobilize Pb{sup 2+} from contaminated soil.

  7. Characteristics of biochars from crop residues: potential for carbon sequestration and soil amendment.

    Science.gov (United States)

    Windeatt, Jayne H; Ross, Andrew B; Williams, Paul T; Forster, Piers M; Nahil, Mohamad A; Singh, Surjit

    2014-12-15

    Biochar has potential to sequester carbon in soils and simultaneously improve soil quality and plant growth. More understanding of biochar variation is needed to optimise these potential benefits. Slow pyrolysis at 600 °C was undertaken to determine how yields and characteristics of biochars differ when produced from eight different agricultural residues. Biochar properties such as carbon content, surface area, pH, ultimate and proximate analysis, nutrient and metal content and the R50 recalcitrance index were determined. Significant variations seen in biochar characteristics were attributed to feedstock variation since pyrolysis conditions were constant. Biochar yields varied from 28% to 39%. Average carbon content was 51%. Ash content of both feedstocks and biochars were correlated with biochar carbon content. Macronutrients were concentrated during pyrolysis, but biochar macronutrient content was low in comparison to biochars produced from more nutrient rich feedstocks. Most biochars were slightly alkaline, ranging from pH 6.1 to pH 11.6. pH was correlated with biochar K content. Aromaticity was increased with pyrolysis, shown by a reduction in biochar H/C and O/C ratios relative to feedstock values. The R50 recalcitrance index showed biochars to be either class 2 or class 3. Biochar carbon sequestration potential was 21.3%-32.5%. The R50 recalcitrance index is influenced by the presence of alkali metals in the biochar which may lead to an under-estimation of biochar stability. The residues assessed here, at current global availability, could produce 373 Mt of biochar. This quantity of biochar has the potential to sequester 0.55 Pg CO2 yr(-1) in soils over long time periods.

  8. Application of grey model on analyzing the passive natural circulation residual heat removal system of HTR-10

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tao; PENG Changhong; WANG Zenghui; WANG Ruosu

    2008-01-01

    Using the grey correlation analysis, it can be concluded that the reactor pressure vessel wall temperature has the strongest effect on the passive residual heat removal system in HTR (High Temperature gas-cooled Reactor),the chimney height takes the second place, and the influence of inlet air temperature of the chimney is the least. This conclusion is the same as that analyzed by the traditional method. According to the grey model theory, the GM(1,1) and GM(1, 3) model are built based on the inlet air temperature of chimney, pressure vessel temperature and the chimney height. Then the effect of three factors on the heat removal power is studied in this paper. The model plays an important role on data prediction, and is a new method for studying the heat removal power. The method can provide a new theoretical analysis to the passive residual heat removal system of HTR.

  9. Conservation agriculture and tillage effects on soil organic matter and residual moisture content in selected upland crop production systems in the Philippines

    OpenAIRE

    Ella, Victor B.; Reyes, Manuel R.; Padre, R.; Mercado, Agustin R., Jr.

    2014-01-01

    This presentation describes a study to analyze the influence of conservation agriculture and tillage on soil organic matter and residual moisture content in selected upland crop production systems in the Philippines LTRA-12 (Conservation agriculture for food security in Cambodia and the Philippines)

  10. Assessment of Ex-Vitro Anaerobic Digestion Kinetics of Crop Residues Through First Order Exponential Models: Effect of LAG Phase Period and Curve Factor

    Directory of Open Access Journals (Sweden)

    Abdul Razaque Sahito

    2013-04-01

    Full Text Available Kinetic studies of AD (Anaerobic Digestion process are useful to predict the performance of digesters and design appropriate digesters and also helpful in understanding inhibitory mechanisms of biodegradation. The aim of this study was to assess the anaerobic kinetics of crop residues digestion with buffalo dung. Seven crop residues namely, bagasse, banana plant waste, canola straw, cotton stalks, rice straw, sugarcane trash and wheat straw were selected from the field and were analyzed on MC (Moisture Contents, TS (Total Solids and VS (Volatile Solids with standard methods. In present study, three first order exponential models namely exponential model, exponential lag phase model and exponential curve factor model were used to assess the kinetics of the AD process of crop residues and the effect of lag phase and curve factor was analyzed based on statistical hypothesis testing and on information theory. Assessment of kinetics of the AD of crop residues and buffalo dung follows the first order kinetics. Out of the three models, the simple exponential model was the poorest model, while the first order exponential curve factor model is the best fit model. In addition to statistical hypothesis testing, the exponential curve factor model has least value of AIC (Akaike's Information Criterion and can generate methane production data more accurately. Furthermore, there is an inverse linear relationship between the lag phase period and the curve factor.

  11. Effectiveness of the GAEC cross-compliance standard management of stubble and crop residues in the maintenance of adequate contents of soil organic carbon

    Directory of Open Access Journals (Sweden)

    Domenico Ventrella

    2011-08-01

    Full Text Available Several studies carried out on the effects of stubble and crop residue incorporation have shown positive effects on chemical-physical soil characteristics. However, not all studies agree on the extent of soil organic matter increase which derives from this process, as this effect is strongly affected by other factors: the pedo-climatic features of the area in which the study is carried out, the type of crop residue incorporation and the agronomical management adopted to improve the decomposition of the incorporated fresh organic material. The burning of stubble and straw is common in the areas where cereals are traditionally grown. The adoption of this method is based on different technical and work-related factors, which become less important when taking into account the impact on the local environment and soil. A research is currently carried out at the CRA-SCA experimental farm in Foggia (Southern Italy on the effects of either residues incorporation or burning on the chemical-physical characteristics of the soil and on the wheat yield performance since 1977. This experiment allows for a comparison among the effects of burning, the simple incorporation of stubble and crop residues and incorporation carried out with some agronomical techniques (such as the distribution of increasing amounts of nitrogen on crop residue before incorporation and the simulation of rain (50 mm on the decomposition of organic material. The objective of the study was to understand the effect of the different residues management practices on soil chemical properties after 32 years of experimentation. The simple incorporation of straw and stubble showed a slight increase in organic soil matter of 0.7% with respect to burning. The best results for soil organic carbon and soil quality were obtained when residual incorporation included a treatment with additional mineral nitrogen.

  12. MODIFIED LAYER REMOVAL METHOD FOR MEASUREMENT OF RESIDUAL STRESS DISTRIBUTION IN THICK PRE-STRETCHED ALUMINUM PLATE

    Institute of Scientific and Technical Information of China (English)

    WANGShu-hong; ZUODun-wen; WANGMin; WANGZong-rong

    2004-01-01

    The integrated structure parts are widely used in aircraft. The distortion caused by residual stresses in thick pre-stretched aluminum plates during machining integrated parts is a common and serious problem. To predict and control the machining distortion, the residual stress distribution in the thick plate must be measured firstly. The modified removal method for measuring residual stress in thick pre-stretched aluminum plates is proposed and the stress-strain relation matrix is deduced by elasticity theory. The residual stress distribution in specimen of 7050T7451 plate is measured by using the method, and measurement results are analyzed and compared with data obtained by other methods. The method is effective to measure the residual stress.

  13. Municipal household waste used as complement material for composting chicken manure and crop residues

    Directory of Open Access Journals (Sweden)

    Guillaume L. Amadji

    2013-06-01

    Full Text Available There are few organic materials available as agricultural soil amendment because their low chemical content means that large quantities are required. In order to improve the availability of raw materials for composting, as well as the quality of the compost produced, municipal solid waste (MW was added to cotton-seed residue (CSR and to the association of CSR with chicken manure (M in different weight/weight (MW/added materials ratios of 5:1 and 2:1. Aerobic composting was processed and compost yield was determined, as well as compost particle size and pH. Also, the compost bulk density and its water holding capacity were determined as well as contents of total nitrogen, carbon, phosphorus, calcium (Ca, magnesium and heavy metals. According to its pH and carbon/nitrogen ratio values, the municipal waste of Cotonou was judged to be a good raw material for composting in order to improve availability of the organic source of nutrients. The composts produced with MW+M+CSR had the highest potential for amending Ferralsols, especially with a mixture of 2:1 (200 kg MW+100 kg M+100 kg CSR that could be applied at 10 t ha–1. However, further improvement in composting methods was suggested to increase Ca++ and reduce mercury contents, respectively. Moreover, potassium balance should be improved in the produced compost.

  14. Prioritizing stream types according to their potential risk to receive crop plant material--A GIS-based procedure to assist in the risk assessment of genetically modified crops and systemic insecticide residues.

    Science.gov (United States)

    Bundschuh, Rebecca; Kuhn, Ulrike; Bundschuh, Mirco; Naegele, Caroline; Elsaesser, David; Schlechtriemen, Ulrich; Oehen, Bernadette; Hilbeck, Angelika; Otto, Mathias; Schulz, Ralf; Hofmann, Frieder

    2016-03-15

    Crop plant residues may enter aquatic ecosystems via wind deposition or surface runoff. In the case of genetically modified crops or crops treated with systemic pesticides, these materials may contain insecticidal Bt toxins or pesticides that potentially affect aquatic life. However, the particular exposure pattern of aquatic ecosystems (i.e., via plant material) is not properly reflected in current risk assessment schemes, which primarily focus on waterborne toxicity and not on plant material as the route of uptake. To assist in risk assessment, the present study proposes a prioritization procedure of stream types based on the freshwater network and crop-specific cultivation data using maize in Germany as a model system. To identify stream types with a high probability of receiving crop materials, we developed a formalized, criteria-based and thus transparent procedure that considers the exposure-related parameters, ecological status--an estimate of the diversity and potential vulnerability of local communities towards anthropogenic stress--and availability of uncontaminated reference sections. By applying the procedure to maize, ten stream types out of 38 are expected to be the most relevant if the ecological effects from plant-incorporated pesticides need to be evaluated. This information is an important first step to identifying habitats within these stream types with a high probability of receiving crop plant material at a more local scale, including accumulation areas. Moreover, the prioritization procedure developed in the present study may support the selection of aquatic species for ecotoxicological testing based on their probability of occurrence in stream types having a higher chance of exposure. Finally, this procedure can be adapted to any geographical region or crop of interest and is, therefore, a valuable tool for a site-specific risk assessment of crop plants carrying systemic pesticides or novel proteins, such as insecticidal Bt toxins, expressed

  15. Experimental design to monitor the influence of crop residue management on the dynamics of soil water content

    Science.gov (United States)

    Chélin, Marie; Hiel, Marie-Pierre; Parvin, Nargish; Bodson, Bernard; Degré, Aurore; Nguyen, Frédéric; Garré, Sarah

    2015-04-01

    Choices related to crop residue management affecting soil structure determine spatio-temporal dynamics of water content and eventually crop yields. In this contribution, we will discuss the experimental design we adopted to study the influence of agricultural management strategies (tillage and residue management) on the soil water dynamics under maize in a Cutanic Siltic Luvisol in Gembloux, Belgium. Three different treatments will be studied: a conventional ploughing realized either in December 2014 or just before sowing in April 2015, and a strip tillage in April 2015. A bare soil under conventional ploughing will also be monitored in order to better understand the influence of the plant over the growing season. In order to limit soil disturbance, we opted for the use of electrical resistivity tomography (ERT) and we use the bulk electrical conductivity as a proxy for soil moisture content. ERT will be collected every week on a surface of two square meters corresponding to three rows of seven maize plants through surface stainless steel electrodes. Five additional sticks with stainless steel electrodes will be vertically inserted into the soil up to 1.50 m to get more detailed information near to the central maize row. In each of the monitoring plots, two time-domain reflectometry (TDR) probes will be installed for data validation. In order to calibrate the relationship between electrical resistivity and soil water content under highly variable field conditions (changes in soil structure, variable weather conditions, plant growth, fertilization), a trench will be dug, in which a set of four electrodes, one TDR probe and one temperature sensor will be placed at four different depths. In addition, two suction cups will be installed in each of the plots to quantify changes in ion composition and electrical conductivity of the soil solution at two different depths. Within the framework of the multidisciplinary research platform AgricultureIsLife, regular assessment

  16. Mechanism of removal of undesirable residual amylase, insoluble starch, and select colorants from refinery streams by powdered activated carbons

    Science.gov (United States)

    There is a need in the world-wide sugar industry to find a practical and economical solution to remove or inactivate residual alpha-amylase that are high temperature stable from factory or refinery streams. A survey of refineries that used amylase and had activated carbon systems for decolorization,...

  17. Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies.

    Science.gov (United States)

    Martínez-Alcántara, Belén; Martínez-Cuenca, Mary-Rus; Fernández, Carlos; Legaz, Francisco; Quiñones, Ana

    2016-01-01

    Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

  18. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  19. Removal of prioritary pesticides contamining r'mel ground water by using organic waste residues.

    Science.gov (United States)

    El Bakouri, H; Morillo, J; Usero, J; Ouassini, A

    2007-01-01

    This study evaluated pesticide contamination of R'mel ground water located in northwest Morocco. The study area is densely populated and thriving, with intensive agriculture. Various techniques, including stir bar sorptive extraction (SBSE) and gas chromatography with mass spectroscopy detection (GC-MS), were used for the quantitative determination of 13 pesticides including alachlor, aldrin, atrazine, chlorpyrifos, chlorfenvinphos, dieldrin, alpha-endosulfan, endrin, hexachlorobenzene, beta-HCH, gamma-HCH (lindane), simazine and trifluralin. The survey results showed that contamination by pesticide residues is widespread in the area. With the exception of atrazine, the average concentrations were all below the regulatory limits established by the European Union. The potential of ten natural organic substances to eliminate pesticides included in the European Water Framework Directive was evaluated. The absorbents with the highest removal efficiency were date and olives stones and, to a Lesser degree, Raphanus raphanistrum and Cistus ladaniferus. The adsorption tests gave very satisfying results and pointed to the possible application of these supports as ecoLogical remediation techniques to prevent pesticide pollution of aquatic ecosystems.

  20. 茶树油清除豇豆农药残留的效果%Effects of tea tree oils on removing pesticide residue in cowpea

    Institute of Scientific and Technical Information of China (English)

    林丽静; 程盛华; 李积华; 黄茂芳; 唐永富; 朱德明

    2013-01-01

    Pesticides are widely used as an insurance policy against devastating crop losses from pests and diseases. Excessive usage of pesticides may lead to contamination of the crop and the environment, eventually posing a risk of pesticide-related illnesses to humans. Previous literature has shown that water washing is only partially effective in removing pesticides, and in the case of liposoluble pesticides, a cosolvent must be used as an adjuvant. Recently, naturally occurring adjuvants are gaining prominence over synthetic chemical compounds. Tea tree oil (TTO, the oil of Melaleuca alternifolia), a natural, volatile essential oil, is mainly extracted by steam distillation from the fresh leaves and terminal branchlets of the plant. It has attracted significant interest due to its antifungal, antiviral, and antibacterial bioactivities. However, to the best of our knowledge, there are fewer experimental data evaluating its efficacy in the removal of pesticide residues. In this study, the effects of TTO on removing pesticide residue were carried out in the cowpea. Volume:volume (v:v) concentrations of 0.05%, 0.1%, 0.2%, 0.4% and 0.8% of TTO and water soluble tea tree oil (WTTO) in water were used to remove a standardized pesticide mixture (organophosphorus, pyrethroid, and carbamate compounds) from cowpeas. Sample pretreatment (pesticide application to cowpeas) was performed according to agricultural industry standards. The objective pesticide residues in cowpeas were assayed by gas chromatography (GC) and chromatography-mass spectrometry detection (GC-MS), and then the clearance rate was calculated. The results showed that TTO was able to remove the three kinds of pesticides from cowpeas. Moreover, the removal efficiency increased with increasing concentration of TTO. The effect of clearing organophosphate was much more obvious than that of either pyrethroid or carbamate. It was suggested that small liposoluble molecules of TTO rapidly infiltrate the cowpea surface to

  1. Semi-continuous anaerobic co-digestion of dairy manure with three crop residues for biogas production.

    Science.gov (United States)

    Li, Jiang; Wei, Luoyu; Duan, Qiwu; Hu, Guoquan; Zhang, Guozhi

    2014-03-01

    The characteristics of anaerobic semi-continuous co-digestion of dairy manure (DM) with three crop straw residues (SRs), rice straw, corn stalks and wheat straw under five mass mixing ratios (SRs/DM) were investigated. During the anaerobic digestion (AD) process, four periods were identified: startup, first stage of stabilization, second stage of stabilization, and suppression. Following the four periods, the biogas production rate varied between 101 and 576mL L(-1)d(-1). A high CH4 content and volatile solid reduction was maintained at the SRs/DM mass mixing ratio 1:9. The highest cumulative biogas production of more than 19L was obtained at ratio 5:5. However, ratio 9:1 performed worst in the whole process. Systematic analysis of the elements revealed nitrogen, phosphorus, and trace elements contents were important for the AD. Overall, the semi-continuous AD is efficient within a wide range of SRs/DM mass mixing ratios.

  2. Watershed Scale Optimization to Meet Sustainable Cellulosic Energy Crop Demand

    Energy Technology Data Exchange (ETDEWEB)

    Chaubey, Indrajeet [Purdue Univ., West Lafayette, IN (United States); Cibin, Raj [Purdue Univ., West Lafayette, IN (United States); Bowling, Laura [Purdue Univ., West Lafayette, IN (United States); Brouder, Sylvie [Purdue Univ., West Lafayette, IN (United States); Cherkauer, Keith [Purdue Univ., West Lafayette, IN (United States); Engel, Bernard [Purdue Univ., West Lafayette, IN (United States); Frankenberger, Jane [Purdue Univ., West Lafayette, IN (United States); Goforth, Reuben [Purdue Univ., West Lafayette, IN (United States); Gramig, Benjamin [Purdue Univ., West Lafayette, IN (United States); Volenec, Jeffrey [Purdue Univ., West Lafayette, IN (United States)

    2017-03-24

    The overall goal of this project was to conduct a watershed-scale sustainability assessment of multiple species of energy crops and removal of crop residues within two watersheds (Wildcat Creek, and St. Joseph River) representative of conditions in the Upper Midwest. The sustainability assessment included bioenergy feedstock production impacts on environmental quality, economic costs of production, and ecosystem services.

  3. Pesticide residue concentration in soil following conventional and Low-Input Crop Management in a Mediterranean agro-ecosystem, in Central Greece

    Energy Technology Data Exchange (ETDEWEB)

    Karasali, Helen, E-mail: e.karassali@bpi.gr [Laboratory of Chemical Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece); Marousopoulou, Anna [Laboratory of Chemical Control of Pesticides, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece); Machera, Kyriaki, E-mail: k.machera@bpi.gr [Laboratory of Pesticides Toxicology, Department of Pesticides Control and Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, Kifissia, 14561 Athens (Greece)

    2016-01-15

    The present study was focused on the comparative evaluation of pesticide residues, determined in soil samples from Kopaida region, Greece before and after the implementation of Low-Input Crop Management (LCM) protocols. LCM has been suggested as an environmental friendly plant protection approach to be applied on crops growing in vulnerable to pollution ecosystems, with special focus on the site specific problems. In the case of the specific pilot area, the vulnerability was mainly related to the pollution of water bodies from agrochemicals attributed to diffuse pollution primarily from herbicides and secondarily from insecticides. A total of sixty-six soil samples, were collected and analyzed during a three-year monitoring study and the results of the determined pesticide residues were considered for the impact evaluation of applied plant protection methodology. The LCM was developed and applied in the main crops growing in the pilot area i.e. cotton, maize and industrial tomato. Herbicides active ingredients such as ethalfluralin, trifluralin, pendimethalin, S-metolachlor and fluometuron were detected in most samples at various concentrations. Ethalfluralin, which was the active ingredient present in the majority of the samples ranged from 0.01 μg g{sup −1} to 0.26 μg g{sup −1} soil dry weight. However, the amount of herbicides measured after the implementation of LCM for two cropping periods, was reduced by more than 75% in all cases. The method of analysis was based on the simultaneous extraction of the target compounds by mechanical shaking, followed by liquid chromatography mass spectrometric and gas chromatography electron capture (LC–MS/MS and GC–ECD) analysis. - Highlights: • Effect of Low Input Crop Management (LCM) in a vulnerable to pollution ecosystem. • LCM resulted in herbicide residues reduction in the range of 75 and 100% in all cases. • Conventional practices resulted in increased herbicide residues up to 18%. • Anthropogenic

  4. Removal of copper from acid wastewater of bioleaching by adsorption onto ramie residue and uptake by Trichoderma viride.

    Science.gov (United States)

    Wang, Buyun; Wang, Kai

    2013-05-01

    A continuous batch bioleaching was built to realize the bioleaching of sewage sludge in large scale. In the treatment, heavy metal in acid wastewater of bioleaching was removed by adsorption onto ramie residue. Then, acid wastewater was reused in next bioleaching batch. In this way, most time and water of bioleaching was saved and leaching efficiency of copper, lead and chromium kept at a high level in continuous batch bioleaching. It was found that residual heavy metal in sewage sludge is highly related to that in acid wastewater after bioleaching. To get a high leaching efficiency, concentration of heavy metal in acid wastewater should be low. Adsorption of copper from acid wastewater onto ramie residue can be described by pseudo first-order kinetics equation and Freundlich isotherm model. Trichoderma viride has the potential to be used for the concentration and recovery of heavy metal adsorbed onto ramie residue. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Assessment of a design to monitor the influence of crop residue management on the dynamics of soil water content with ERT

    Science.gov (United States)

    Chelin, Marie; Hiel, Marie-Pierre; Hermans, Thomas; Binley, Andrew; Garre, Sarah

    2016-04-01

    Choices related to crop residue management affect the soil structure. As a consequence, they may determine the spatio-temporal dynamics of water content and eventually the crop yields. In order to better understand the influence of these strategies on hydraulic processes occurring at the plot scale, we opted for the use electrical resistivity tomography (ERT). This approach presents the advantage to limit soil disturbance but is still faced to important challenges when applied in an agricultural field context. Especially changing soil-electrode contact has to be considered, as it can lead to bad quality data, especially for setups with small electrodes and small inter-electrode distance. The objective of this study was to test the efficiency of a high-resolution 3-D field measurement design to properly assess the dynamics of soil water content. ERT measurements were conducted in a Cutanic Siltic Luvisol in Gembloux, Belgium, on two plots of 2m2 ploughed in Oct 2014 at a depth of 25 cm and sown with maize in April 2015. The plants were removed on one of the plots in order to obtain a bare soil reference. A grid of 98 surface stainless steel electrodes was layed-out on each plot and four sticks supporting each eight stainless steel electrodes were vertically inserted into the soil up to 1.20 m to get more detailed information in depth. The experiments were performed between Jul and Oct 2015, in order to get measurements both in dry and wet periods. For surface and borehole monitoring, a dipole-dipole array configuration including in-line and cross-line measurements was adopted. Normal and reciprocal measurements were performed systematically to assess the data quality: only the datasets with a mean reciprocal error lower than 3% were considered for the data inversion. This contribution will show the first inverted results showing the complexity of experimental design and data analysis for high-resolution, timelapse ERT in field conditions. Based on these results, we

  6. A method to remove residual signals in fibre optic luminescence dosimeters.

    Science.gov (United States)

    Lee, J J; Liu, P Z Y; McKenzie, D R; Suchowerska, N

    2013-03-07

    Whenever a fibre optic is used to convey a light signal through a radiation field, it is likely that an unwanted background signal will arise from Cerenkov or fluorescent light which will contaminate the signal. In luminescence dosimetry of high energy beams, when a fibre optic is used to convey the signal from the radiation field to the detector, Cerenkov light is the dominant contributor to the background signal and must be corrected for. In this work, a novel method is demonstrated to separate the signal from the unwanted background. A remotely operated shutter is used to block the signal, allowing the residual background in the fibre optic to be quantified. This background is subtracted from the total measurement acquired in a subsequent irradiation, enabling the luminescence signal to be extracted. Two types of shutter mechanism are considered: an electro-mechanical device to intercept the light path and an LCD device to block the light by cross-polarization. Both shutters were characterized and incorporated into a fibre optic dosimetry system used to measure the radiation dose produced by external beam radiation linear accelerators. The dosimeter using each of the shutters in turn was exposed to a 6 MV photon beam to determine their performance, including the measurement of field size dependent output factors. The mechanical shutter determined the output factors to within 0.29% of those measured with an ionization chamber, whereas the LCD shutter gave results that deviated by up to 2.4%. The switching precision of both shutters was good with standard deviations of less than 0.25% and both were able to completely block the light signal when closed. The use of shutters could therefore be applied to any fibre optic based system to quantify and remove a reproducible background arising from any source including ambient, fluorescent and Cerenkov light.

  7. Nutrient removal capacity of wood residues for the Agro-environmental safety of ground and surface waters

    Directory of Open Access Journals (Sweden)

    Paulo A. Dumont

    2014-07-01

    Full Text Available The aim of this study was to determine the effectiveness of wood residues in the removal of nutrients (ammonium-N; NH4-N from nutrient-rich (NH4-N waters. The water holding capacity of the wood materials was also determined. Carried out at Rothamsted Research, North Wyke, UK, this controlled laboratory experiment tested two wood residues; in length, one being 1-2cm and the other from 150 µm (microns to 9.5mm. Although a wide range of studies have shown the effectiveness and performance of various absorbent materials as animal beddings, such as straw (cereal straw, woodchip (sawdust, bark or wood shavings, bracken and rushes, only few have focused on the NH4-N sorption/desorption capacity. The depuration capacity of wood residues from nutrient-rich effluents such as those from cattle bedded on woodchip or straw will be controlled by processes such as sorption (adsorption-absorption and desorption of nutrients. Studies have reported the nitrogen removal capacity of woodchip materials and biochar from woodchip as well as removal of NH4+-N from domestic and municipal wastewater, farm dirty water, landfill and industry effluents. These studies have observed that the mechanism of removal of nitrogen is by either increasing NO3--N removal form leachate by enhancing N2O losses via denitrification (biochar as carbon source for denitrifiers or by decreasing NH4+-N in leachate through adsorption to negatively charged sites. Results showed that although the cation exchange capacity (CEC and surface area (SA are both fundamental properties of adsorbent materials, no correlation was found with CEC and adsorption or desorption. Nor did changes in pH appear to be sufficiently important to cause changes in CEC. For this reason, osmotic pressure appeared to be a more predominant parameter controlling processes of adsorption and desorption of NH4+-N in both wood residues. Thus, wood residues high in NH4+-N should be avoided, as they could have an opposite effect

  8. Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies.

    Directory of Open Access Journals (Sweden)

    Belén Martínez-Alcántara

    Full Text Available Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L. grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95% ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

  9. Calcium hydroxide dressing residues after different removal techniques affect the accuracy of Root-ZX apex locator

    Science.gov (United States)

    Eymirli, Ayhan; Uyanik, Mehmet Özgür; Çalt, Semra; Nagas, Emre

    2015-01-01

    Objectives This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator. Materials and Methods Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software. Results The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p 85% within a tolerance of ± 1.0 mm (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ± 0.5 mm; r = -0.940 for ± 1.0 mm). Conclusions The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely. PMID:25671212

  10. Slow pyrolyzed biochars from crop residues for soil metal(loid) immobilization and microbial community abundance in contaminated agricultural soils.

    Science.gov (United States)

    Igalavithana, Avanthi Deshani; Park, Jinje; Ryu, Changkook; Lee, Young Han; Hashimoto, Yohey; Huang, Longbin; Kwon, Eilhann E; Ok, Yong Sik; Lee, Sang Soo

    2017-06-01

    This study evaluated the feasibility of using biochars produced from three types of crop residues for immobilizing Pb and As and their effects on the abundance of microbial community in contaminated lowland paddy (P-soil) and upland (U-soil) agricultural soils. Biochars were produced from umbrella tree [Maesopsis eminii] wood bark [WB], cocopeat [CP], and palm kernel shell [PKS] at 500 °C by slow pyrolysis at a heating rate of 10 °C min(-1). Soils were incubated with 5% (w w(-1)) biochars at 25 °C and 70% water holding capacity for 45 d. The biochar effects on metal immobilization were evaluated by sequential extraction of the treated soil, and the microbial community was determined by microbial fatty acid profiles and dehydrogenase activity. The addition of WB caused the largest decrease in Pb in the exchangeable fraction (P-soil: 77.7%, U-soil: 91.5%), followed by CP (P-soil: 67.1%, U-soil: 81.1%) and PKS (P-soil: 9.1%, U-soil: 20.0%) compared to that by the control. In contrast, the additions of WB and CP increased the exchangeable As in U-soil by 84.6% and 14.8%, respectively. Alkalinity and high phosphorous content of biochars might be attributed to the Pb immobilization and As mobilization, respectively. The silicon content in biochars is also an influencing factor in increasing the As mobility. However, no considerable effects of biochars on the microbial community abundance and dehydrogenase activity were found in both soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Effects of agriculture crop residue burning on aerosol properties and long-range transport over northern India: A study using satellite data and model simulations

    Science.gov (United States)

    Vijayakumar, K.; Safai, P. D.; Devara, P. C. S.; Rao, S. Vijaya Bhaskara; Jayasankar, C. K.

    2016-09-01

    Agriculture crop residue burning in the tropics is a major source of the global atmospheric aerosols and monitoring their long-range transport is an important element in climate change studies. In this paper, we study the effects of agriculture crop residue burning on aerosol properties and long-range transport over northern India during a smoke event that occurred between 09 and 17 November 2013, with the help of satellite measurements and model simulation data. Satellite data observations on aerosol properties suggested transport of particles from agriculture crop residue burning in Indo-Gangetic Plains (IGP) over large regions. Additionally, ECMWF winds at 850 hPa have been used to trace the source, path and spatial extent of smoke events. Most of the smoke aerosols, during the study period, travel from a west-to-east pathway from the source-to-sink region. Furthermore, aerosol vertical profiles from CALIPSO show a layer of thick smoke extending from surface to an altitude of about 3 km. Smoke aerosols emitted from biomass burning activity from Punjab have been found to be a major contributor to the deterioration of local air quality over the NE Indian region due to their long range transport.

  12. Factors involved in alleviating water stress by partial crop removal in pear trees.

    Science.gov (United States)

    Marsal, Jordi; Mata, Merce; Arbones, Amadeu; Del Campo, Jesus; Girona, Joan; Lopez, Gerardo

    2008-09-01

    We studied the relief of water stress associated with fruit thinning in pear (Pyrus communis L.) trees during drought to determine what mechanisms, other than stomatal adjustment, were involved. Combinations of control irrigation (equal to crop water use less effective rainfall) and deficit irrigation (equal to 20% of control irrigation), fruit load (unthinned and thinned to 40 fruits per tree) and root pruning (pruned and unpruned) treatments were applied to pear (cv. 'Conference') trees during Stage II of fruit development. Daily patterns of midday stem water potential (Psi(stem)) and leaf conductance to water vapor (g(l)) of deficit-irrigated trees differed after fruit thinning. In response to fruit thinning, gl progressively declined with water stress until 30 days after fruit thinning and then leveled off, whereas the effects of decreased fruit load on Psi(stem) peaked 30-40 days after fruit thinning and then tended to decline. Soil water depletion was significantly correlated with fruit load during drought. Our results indicate that stomatal adjustment and the resulting soil water conservation were the factors determining the Psi(stem) response to fruit thinning. However, these factors could not explain differences in daily patterns between g(l) and Psi(stem) after fruit thinning. In all cases, effects of root pruning treatments on Psi(stem) in deficit-irrigated trees were transitory (Psi(stem) recovered from root pruning in less than 30 days), but the recovery of Psi(stem) after root pruning was faster in trees with low fruit loads. This behavior is compatible with the concept that the water balance (reflected by Psi(stem) values) was better in trees with low fruit loads compared with unthinned trees, perhaps because more carbon was available for root growth. Thus, a root growth component is hypothesized as a mechanism to explain the bimodal Psi(stem) response to fruit thinning during drought.

  13. Decomposition, contribution and soil organic matter balances of crop residues and vermicompost in maize-based cropping systems in southwest Mexico

    NARCIS (Netherlands)

    Flores Sanchez, D.; Pastor, A.; Rossing, W.A.H.; Kropff, M.J.; Lantinga, E.A.

    2016-01-01

    Soil fertility depletion is one of the main concerns of the farmers in the Costa Chica, Mexico. The current crop management exacerbates nutrient cycling unbalances and threatens the sustainability of the common maize production systems. It is necessary to supply the soil with organic sources. Field

  14. EVALUATION OF FERRIC CHLORIDE AND ALUM EFFICIENCIES IN ENHANCED COAGULATION FOR TOC REMOVAL AND RELATED RESIDUAL METAL CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    A. Mesdaghinia, M. T. Rafiee, F. Vaezi and A. H. Mahvi

    2005-07-01

    Full Text Available Although the removal of colloidal particles continues to be an important reason for using coagulation, a newer objective, the removal of natural organic matter (NOM to reduce the formation of disinfection by-products (DBPs, is growing in importance. Enhanced coagulation is thus introduced to most water utilities treating surface water. Bench-scale experiments were conducted to compare the effectiveness of alum and ferric chloride in removing DBPs precursors from eight synthetic water samples, each representing a different element of the USEPA’s 3×3 enhanced coagulation matrix. The effect of enhanced coagulation on the residual metal (aluminum/iron concentration in the treated water was assessed as well. The removal of total organic carbon (TOC was dependent on the coagulant type and was enhanced with increasing coagulant dose, but the latter had no further considerable effect in case of increasing to high levels. For all the treated samples coagulation with ferric chloride proved to be more effective than alum at similar doses and the mean values of treatment efficiencies were 51% and 32% for ferric chloride and alum, respectively. Ferric chloride was therefore considered the better chemical for enhancing the coagulation process. Besides, due to less production of sludge by this coagulant, it would be predicted that treatment plants would be confronted to fewer problems with respect to final sludge disposal. Measurements of residual metal in treated water indicated that iron and aluminum concentrations had been increased as expected but the quality of water concerning the residual metal deteriorated much more in cases of under-dosing. Despite expecting high residual Al and Fe concentrations under enhanced coagulation, metal concentrations were frequently remained low and were not increased appreciably.

  15. Water pressure head and temperature impact on isoxaflutole degradation in crop residues and loamy surface soil under conventional and conservation tillage management.

    Science.gov (United States)

    Alletto, Lionel; Coquet, Yves; Bergheaud, Valérie; Benoit, Pierre

    2012-08-01

    Laboratory incubations were performed in order to evaluate the dissipation of the proherbicide isoxaflutole in seedbed layer soil samples from conventional and conservation tillage systems and in maize and oat residues left at the soil surface under conservation tillage. The effects of temperature and water pressure head on radiolabelled isoxaflutole degradation were studied for each sample for 21d. Mineralisation of isoxaflutole was low for all samples and ranged from 0.0% to 0.9% of applied (14)C in soil samples and from 0.0% to 2.4% of applied (14)C in residue samples. In soil samples, degradation half-life of isoxaflutole ranged from 9 to 26h, with significantly higher values under conservation tillage. In residue samples, degradation half-life ranged from 3 to 31h, with significantly higher values in maize residues, despite a higher mineralisation and bound residue formation than in oat residues. Whatever the sample, most of the applied (14)C remained extractable during the experiment and, after 21d, less than 15% of applied (14)C were unextractable. This extractable fraction was composed of diketonitrile, benzoic acid derivative and several unidentified metabolites, with one of them accounting for more than 17% of applied (14)C. This study showed that tillage system design, including crop residues management, could help reducing the environmental impacts of isoxaflutole.

  16. Beneficial use of meat and bone meal combustion residue: "an efficient low cost material to remove lead from aqueous effluent".

    Science.gov (United States)

    Deydier, Eric; Guilet, Richard; Sharrock, Patrick

    2003-07-04

    Meat and bone meal (MBM) combustion residues, a natural apatite-rich substance, was evaluated as a low cost substitute for hydroxyapatite in lead sequestration from water effluents. The thermal behaviour of crude meat and bone meal was followed by TGA and 24% inorganic residue was collected. The resulting ashes were characterised by powder X-ray diffraction (XRD), particle size distribution, specific surface area (BET), and elemental analysis confirming apatite contents, with high level of phosphate (56.3%) and calcium (36.8%). Mechanism and kinetics of lead removal by this bioinorganic material were investigated and compared to mechanisms and kinetics involved with synthetic apatite. Batch metal removal experiments were carried out with 500 and 1500ppm (mg/kg) Pb(2+) solutions. Lead concentration, calcium and pH were monitored. We observed that the mechanism is similar to that occurring for pure apatite, and involved both surface complexation and calcium hydroyapatite (CaHA), Ca(10)(PO(4))(6)(OH)(2), dissolution followed by less soluble Pb(10)(PO(4))(6)(OH)(2) precipitation, as confirmed by XRD analysis of ashes after incubation with lead solution. Our results show that this natural apatite-rich material removes in a few minutes a large quantity of lead (275mg/g capacity) which remains however lower than the theoretical maximum capacity (if calcium were totally substituted by lead). Meat and bone meal combustion residues represent a valuable alternative apatite source for environmental application.

  17. Suitability of peanut residue as a nitrogen source for a rye cover crop Resíduos da cultura de amendoim como fonte de nitrogênio para uma cultura de cobertura de centeio

    Directory of Open Access Journals (Sweden)

    Kipling Shane Balkcom

    2007-01-01

    Full Text Available Leguminous winter cover crops have been utilized in conservation systems to partially meet nitrogen (N requirements of succeeding summer cash crops, but the potential of summer legumes to reduce N requirements of a winter annual grass, used as a cover crop, has not been extensively examined. This study assessed the N contribution of peanut (Arachis hypogaea L. residues to a subsequent rye (Secale cereale L. cover crop grown in a conservation system on a Dothan sandy loam (fine-loamy, kaolinitic, thermic Plinthic Kandiudults at Headland, AL USA during the 2003-2005 growing seasons. Treatments were arranged in a split plot design, with main plots of peanut residue retained or removed from the soil surface, and subplots as N application rates (0, 34, 67 and 101 kg ha-1 applied in the fall. Peanut residue had minimal to no effect on rye biomass yields, N content, carbon (C /N ratio, or N, P, K, Ca and Zn uptake. Additional N increased rye biomass yield, and N, P, K, Ca, and Zn uptakes. Peanut residue does not contribute significant amounts of N to a rye cover crop grown as part of a conservation system, but retaining peanut residue on the soil surface could protect the soil from erosion early in the fall and winter before a rye cover crop grows sufficiently to protect the typically degraded southeastern USA soils.Culturas leguminosas de inverno tem sido utilizadas em sistemas conservacionistas para suprimento parcial das necessidades de nitrogênio (N de culturas subseqüentes de verão, mas o potencial destas culturas leguminosas de verão no sentido de reduzir as necessidades de N de gramíneas anuais de inverno, utilizadas como culturas de cobertura, ainda não foi extensivamente estudado. Este trabalho avaliou a contribuição dos resíduos de uma cultura de amendoim (Arachis hypogaea L. sobre as necessidades de N de uma cultura subsequente de centeio (Secale cereale L. como cobertura desenvolvida dentro de um sistema conservacionista, em um

  18. Selective weed suppression by cover crop residues: effects of seed mass and timing of species’sensitivity

    NARCIS (Netherlands)

    Kruidhof, H.M.; Gallandt, E.R.; Haramoto, E.R.; Bastiaans, L.

    2011-01-01

    Laboratory bioassays have shown that large-seeded species better tolerate cover crop residue–mediated stress than small-seeded species. This provides the potential for selective suppression of small-seeded weeds in large-seeded crops. We conducted two field experiments in which seedling emergence of

  19. Optimization of removal and recycling ratio of cover crop biomass using carbon balance to sustain soil organic carbon stocks in a mono-rice paddy system

    NARCIS (Netherlands)

    Haque, Md. Mozammel; Kim, Sang Yun; Kim, Gil Won; Kim, Pil Joo

    2015-01-01

    The cultivation of a winter cover crop as green manure is strongly recommended to improve soil quality in mono-rice paddy systems; however, the biomass is largely removed to feed cattle in many Asian regions. To determine the minimum recycling ratio of the biomass that can sustain soil organic carbo

  20. Efficiencies of residual organic pollutants removal from secondary effluent by switching of coagulation- air flotation -filtration processes.

    Science.gov (United States)

    Huang, R; Zhang, J; Ma, L; Jiang, A; Kong, X J; Li, X K; Bao, L

    2006-01-01

    It is an essential task to remove the residual organic pollutants (ROP) from secondary effluent of a Wastewater Treatment Plant (WWTP) in wastewater reclamation and reuse processes. Four different compared flow schemes would be achieved for further purification of the secondary effluent by switching of different valves. In order to mainly remove non-biodegradable residual organic pollutants under various operating conditions, the optimum technology and economic process was obtained in the advanced purification flow scheme at a flow of 3200 m(3)/d in Harbin Wenchang WWTP. Conclusions under a lot of experiments show that: choosing the coagulation-settler plus biofilm filter for advanced purification process is reasonable; during the stable operation phase, this process showed good performance in removing the COD, BOD5, TP, NH3-N and SS; the removal rates are 50%, 39%, 67%, 50%, 80% respectively. The effluent is able to excel the requirements for wastewater reuse standards. The unit cost of the water is 0.542 yuan/m(3), which is far below the fee paid for supply water, long-distance transfer water or seawater desalination through economic analysis.

  1. Removal of uranyl ions from residual waters using some algae types

    NARCIS (Netherlands)

    Cecal, A; Palamaru, [No Value; Humelnicu, D; Popa, K; Salaru, VV; Rudic, [No Value; Gulea, A

    1999-01-01

    This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillinium sp, as well as the Glucide extract of Porphyridium cruentum, under

  2. Sensitivity analysis of six soil organic matter models applied to the decomposition of animal manures and crop residues

    Directory of Open Access Journals (Sweden)

    Daniele Cavalli

    2016-09-01

    Full Text Available Two features distinguishing soil organic matter simulation models are the type of kinetics used to calculate pool decomposition rates, and the algorithm used to handle the effects of nitrogen (N shortage on carbon (C decomposition. Compared to widely used first-order kinetics, Monod kinetics more realistically represent organic matter decomposition, because they relate decomposition to both substrate and decomposer size. Most models impose a fixed C to N ratio for microbial biomass. When N required by microbial biomass to decompose a given amount of substrate-C is larger than soil available N, carbon decomposition rates are limited proportionally to N deficit (N inhibition hypothesis. Alternatively, C-overflow was proposed as a way of getting rid of excess C, by allocating it to a storage pool of polysaccharides. We built six models to compare the combinations of three decomposition kinetics (first-order, Monod, and reverse Monod, and two ways to simulate the effect of N shortage on C decomposition (N inhibition and C-overflow. We conducted sensitivity analysis to identify model parameters that mostly affected CO2 emissions and soil mineral N during a simulated 189-day laboratory incubation assuming constant water content and temperature. We evaluated model outputs sensitivity at different stages of organic matter decomposition in a soil amended with three inputs of increasing C to N ratio: liquid manure, solid manure, and low-N crop residue. Only few model parameters and their interactions were responsible for consistent variations of CO2 and soil mineral N. These parameters were mostly related to microbial biomass and to the partitioning of applied C among input pools, as well as their decomposition constants. In addition, in models with Monod kinetics, CO2 was also sensitive to a variation of the half-saturation constants. C-overflow enhanced pool decomposition compared to N inhibition hypothesis when N shortage occurred. Accumulated C in the

  3. Assessing the levels of food shortage using the traffic light metaphor by analyzing the gathering and consumption of wild food plants, crop parts and crop residues in Konso, Ethiopia

    Directory of Open Access Journals (Sweden)

    Ocho Dechassa

    2012-08-01

    Full Text Available Abstract Background Humanitarian relief agencies use scales to assess levels of critical food shortage to efficiently target and allocate food to the neediest. These scales are often labor-intensive. A lesser used approach is assessing gathering and consumption of wild food plants. This gathering per se is not a reliable signal of emerging food stress. However, the gathering and consumption of some specific plant species could be considered markers of food shortage, as it indicates that people are compelled to eat very poor or even health-threatening food. Methods We used the traffic light metaphor to indicate normal (green, alarmingly low (amber and fully depleted (red food supplies and identified these conditions for Konso (Ethiopia on the basis of wild food plants (WFPs, crop parts (crop parts not used for human consumption under normal conditions; CPs and crop residues (CRs being gathered and consumed. Plant specimens were collected for expert identification and deposition in the National Herbarium. Two hundred twenty individual households free-listed WFPs, CPs, and CRs gathered and consumed during times of food stress. Through focus group discussions, the species list from the free-listing that was further enriched through key informants interviews and own field observations was categorized into species used for green, amber and red conditions. Results The study identified 113 WFPs (120 products/food items whose gathering and consumption reflect the three traffic light metaphors: red, amber and green. We identified 25 food items for the red, 30 food items for the amber and 65 food items for the green metaphor. We also obtained reliable information on 21 different products/food items (from 17 crops normally not consumed as food, reflecting the red or amber metaphor and 10 crop residues (from various crops, plus one recycled stuff which are used as emergency foods in the study area clearly indicating the severity of food stress (red metaphor

  4. Comparison of residual NAPL source removal techniques in 3D metric scale experiments

    Science.gov (United States)

    Atteia, O.; Jousse, F.; Cohen, G.; Höhener, P.

    2017-07-01

    This study compared four treatment techniques for the removal of a toluene/n-decane as NAPL (Non Aqueous Phase Liquid) phase mixture in identical 1 cubic meter tanks filled with different kind of sand. These four treatment techniques were: oxidation with persulfate, surfactant washing with Tween80®, sparging with air followed by ozone, and thermal treatment at 80 °C. The sources were made with three lenses of 26 × 26 × 6.5 cm, one having a hydraulic conductivity similar to the whole tank and the two others a value 10 times smaller. The four techniques were studied after conditioning the tanks with tap water during approximately 80 days. The persulfate treatment tests showed average removal of the contaminants but significant flux decrease if density effects are considered. Surfactant flushing did not show a highly significant increase of the flux of toluene but allowed an increased removal rate that could lead to an almost complete removal with longer treatment time. Sparging removed a significant amount but suggests that air was passing through localized gas channels and that the removal was stagnating after removing half of the contamination. Thermal treatment reached 100% removal after the target temperature of 80 °C was kept during more than 10 d. The experiments emphasized the generation of a high-spatial heterogeneity in NAPL content. For all the treatments the overall removal was similar for both n-decane and toluene, suggesting that toluene was removed rapidly and n-decane more slowly in some zones, while no removal existed in other zones. The oxidation and surfactant results were also analyzed for the relation between contaminant fluxes at the outlet and mass removal. For the first time, this approach clearly allowed the differentiation of the treatments. As a conclusion, experiments showed that the most important differences between the tested treatment techniques were not the global mass removal rates but the time required to reach 99% decrease in

  5. Estonian waterworks treatment plants: clearance of residues, discharge of effluents and efficiency of removal of radium from drinking water.

    Science.gov (United States)

    Trotti, F; Caldognetto, E; Forte, M; Nuccetelli, C; Risica, S; Rusconi, R

    2013-12-01

    Considerable levels of radium were detected in a certain fraction of the Estonian drinking water supply network. Some of these waterworks have treatment systems for the removal of (mainly) iron and manganese from drinking water. Three of these waterworks and another one equipped with a radium removal pilot plant were examined, and a specific study was conducted in order to assess the environmental compatibility of effluents and residues produced in the plants. (226)Ra and (228)Ra activity concentrations were analysed in both liquid (backwash water) and solid (sand filter and sediment) materials to evaluate their compliance, from the radiological point of view, with current Estonian legislation and international technical documents that propose reference levels for radium in effluents and residues. Also with regard to water treatment by-products, a preliminary analysis was done of possible consequences of the transposition of the European Basic Safety Standards Draft into Estonian law. Radium removal efficiency was also tested in the same plants. Iron and manganese treatment plants turned out to be scarcely effective, whilst the radium mitigation pilot plant showed a promising performance.

  6. Residues of sugar cane crop and its effects on the epigeic invertebrate faunaResíduos da cultura da cana-de-açúcar e seus efeitos sobre a fauna invertebrada epigéica

    Directory of Open Access Journals (Sweden)

    Júlio César Salton

    2011-08-01

    Full Text Available This study aimed to evaluate the effect of the availability of sugar cane residues on the epigeic invertebrate fauna. The evaluations were made after cane sugar harvest f, considering three levels of residues: 0% (total removal of residues from the soil surface, 50% (removal of half of the waste in the plots, the dry mass of 7.6 Mg ha-1 and 100% (keeping track of residues produced, dry mass of 16.9 Mg ha-1. A fragment of native vegetation in the region, located close to the sugar cane crop, was evaluated for comparison. The experimental plots were arranged in a randomized block design with eight replications. Each plot consisted of five rows 20 m long, were installed two pitfalls to capture the invertebrate fauna, representing sixteen traps in each treatment, totaling forty-eight throughout the experiment. The organisms were extracted manually and identified at major taxonomic groups. The highest diversity and groups richness of epigeic invertebrate fauna were observed in the cane sugar crop with the maintenance of the surface residues (100 and 50%. Moreover, complete removal of residues from the soil surface promoted a significant reduction of the soil invertebrates organisms. Soil samples were collected for evaluation of chemical attributes. The organisms of epigeic invertebrate fauna showed sensitive in detecting changes in systems, depending on the maintenance of plant residues of sugar cane.O presente estudo teve como objetivo avaliar o efeito da disponibilidade de resíduos de cana-de-açúcar sobre a fauna invertebrada epigéica. As avaliações foram realizadas após a colheita da cana-de-açúcar, considerando três níveis de resíduos: 0 % (retirada total de resíduos da superfície do solo, 50 % (retirada da metade dos resíduos nas parcelas, massa seca de 7,6 Mg ha-1 e 100 % (manutenção completa dos resíduos produzidos, massa seca de 16,9 Mg ha-1. As parcelas experimentais foram dispostas num delineamento em blocos casualizados

  7. Removal of 16 pesticide residues from strawberries by washing with tap and ozone water, ultrasonic cleaning and boiling.

    Science.gov (United States)

    Lozowicka, Bozena; Jankowska, Magdalena; Hrynko, Izabela; Kaczynski, Piotr

    2016-01-01

    The effects of washing with tap and ozone water, ultrasonic cleaning and boiling on 16 pesticide (ten fungicides and six insecticides) residue levels in raw strawberries were investigated at different processing times (1, 2 and 5 min). An analysis of these pesticides was conducted using gas chromatography with nitrogen-phosphorous and electron capture detection (GC-NPD/ECD). The processing factor (PF) for each pesticide in each processing technique was determined. Washing with ozonated water was demonstrated to be more effective (reduction from 36.1 to 75.1 %) than washing with tap water (reduction from 19.8 to 68.1 %). Boiling decreased the residues of the most compounds, with reductions ranging from 42.8 to 92.9 %. Ultrasonic cleaning lowered residues for all analysed pesticides with removal of up to 91.2 %. The data indicated that ultrasonic cleaning and boiling were the most effective treatments for the reduction of 16 pesticide residues in raw strawberries, resulting in a lower health risk exposure. Calculated PFs for alpha-cypermethrin were used to perform an acute risk assessment of dietary exposure. To investigate the relationship between the levels of 16 pesticides in strawberry samples and their physicochemical properties, a principal component analysis (PCA) was performed. Graphical abstract ᅟ.

  8. New field-based agricultural biomass burning trace gas, PM2.5, and black carbon emission ratios and factors measured in situ at crop residue fires in Eastern China

    Science.gov (United States)

    Zhang, Tianran; Wooster, Martin J.; Green, David C.; Main, Bruce

    2015-11-01

    Despite policy attempts to limit or prevent agricultural burning, its use to remove crop residues either immediately after harvest (e.g. field burning of wheat stubble) or after subsequent crop processing (e.g. "bonfires" of rice straw and rapeseed residues) appears to remain widespread across parts of China. Emission factors for these types of small but highly numerous fire are therefore required to fully assess their impact on atmospheric composition and air pollution. Here we describe the design and deployment of a new smoke measurement system for the close-range sampling of key gases and particles within smoke from crop residue fires, using it to assess instantaneous mixing ratios of CO and CO2 and mass concentrations of black carbon (BC) and PM2.5 from wheat stubble, rice straw, and rapeseed residue fires. Using data of our new smoke sampling system, we find a strong linear correlation between the PM2.5 mass and BC, with very high PM2.5 to BC emission ratios found in the smouldering phase (up to 80.7 mg m-3.(mg m-3)-1) compared to the flaming phase (2.0 mg m-3.(mg m-3)-1). We conclude that the contribution of BC to PM2.5 mass was as high as 50% in the flaming phase of some burns, whilst during smouldering it sometimes decreased to little over one percent. A linear mixing model is used to quantify the relative contribution of each combustion phase to the overall measured smoke composition, and we find that flaming combustion dominated the total emission of most species assessed. Using time series of trace gas concentrations from different fire cases, we calculated 'fire integrated' trace gas emission factors (EFs) for wheat, rice and rapeseed residue burns as 1739 ± 19 g kg-1, 1761 ± 30 g kg-1and 1704 ± 27 g kg-1 respectively for CO2, and 60 ± 12 g kg-1, 47 ± 19 g kg-1 and 82 ± 17 g kg-1 respectively for CO. Where comparisons were possible, our EFs agreed well with those derived via a simultaneously-deployed open path Fourier transform infrared (OP

  9. Use of activated carbons to remove undesirable residual amylase from factory and refinery streams

    Science.gov (United States)

    In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were develope...

  10. Removal of uranyl ions from residual waters using some algae types

    NARCIS (Netherlands)

    Cecal, A; Palamaru, [No Value; Humelnicu, D; Popa, K; Salaru, VV; Rudic, [No Value; Gulea, A

    1999-01-01

    This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillinium sp, as well as the Glucide extract of Porphyridium cruentum, under vario

  11. Pesticide residue concentration in soil following conventional and Low-Input Crop Management in a Mediterranean agro-ecosystem, in Central Greece.

    Science.gov (United States)

    Karasali, Helen; Marousopoulou, Anna; Machera, Kyriaki

    2016-01-15

    The present study was focused on the comparative evaluation of pesticide residues, determined in soil samples from Kopaida region, Greece before and after the implementation of Low-Input Crop Management (LCM) protocols. LCM has been suggested as an environmental friendly plant protection approach to be applied on crops growing in vulnerable to pollution ecosystems, with special focus on the site specific problems. In the case of the specific pilot area, the vulnerability was mainly related to the pollution of water bodies from agrochemicals attributed to diffuse pollution primarily from herbicides and secondarily from insecticides. A total of sixty-six soil samples, were collected and analyzed during a three-year monitoring study and the results of the determined pesticide residues were considered for the impact evaluation of applied plant protection methodology. The LCM was developed and applied in the main crops growing in the pilot area i.e. cotton, maize and industrial tomato. Herbicides active ingredients such as ethalfluralin, trifluralin, pendimethalin, S-metolachlor and fluometuron were detected in most samples at various concentrations. Ethalfluralin, which was the active ingredient present in the majority of the samples ranged from 0.01 μg g(-1) to 0.26 μg g(-1) soil dry weight. However, the amount of herbicides measured after the implementation of LCM for two cropping periods, was reduced by more than 75% in all cases. The method of analysis was based on the simultaneous extraction of the target compounds by mechanical shaking, followed by liquid chromatography mass spectrometric and gas chromatography electron capture (LC-MS/MS and GC-ECD) analysis.

  12. Removal of polycyclic aromatic hydrocarbons from aqueous solution by raw and modified plant residue materials as biosorbents.

    Science.gov (United States)

    Xi, Zemin; Chen, Baoliang

    2014-04-01

    Removal of polycyclic aromatic hydrocarbons (PAHs), e.g., naphthalene, acenaphthene, phenanthrene and pyrene, from aqueous solution by raw and modified plant residues was investigated to develop low cost biosorbents for organic pollutant abatement. Bamboo wood, pine wood, pine needles and pine bark were selected as plant residues, and acid hydrolysis was used as an easily modification method. The raw and modified biosorbents were characterized by elemental analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The sorption isotherms of PAHs to raw biosorbents were apparently linear, and were dominated by a partitioning process. In comparison, the isotherms of the hydrolyzed biosorbents displayed nonlinearity, which was controlled by partitioning and the specific interaction mechanism. The sorption kinetic curves of PAHs to the raw and modified plant residues fit well with the pseudo second-order kinetics model. The sorption rates were faster for the raw biosorbents than the corresponding hydrolyzed biosorbents, which was attributed to the latter having more condensed domains (i.e., exposed aromatic core). By the consumption of the amorphous cellulose component under acid hydrolysis, the sorption capability of the hydrolyzed biosorbents was notably enhanced, i.e., 6-18 fold for phenanthrene, 6-8 fold for naphthalene and pyrene and 5-8 fold for acenaphthene. The sorption coefficients (Kd) were negatively correlated with the polarity index [(O+N)/C], and positively correlated with the aromaticity of the biosorbents. For a given biosorbent, a positive linear correlation between logKoc and logKow for different PAHs was observed. Interestingly, the linear plots of logKoc-logKow were parallel for different biosorbents. These observations suggest that the raw and modified plant residues have great potential as biosorbents to remove PAHs from wastewater. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of

  13. Removal of arsenic from Janghang smelter site and energy crops-grown soil with soil washing using magnetic iron oxide

    Science.gov (United States)

    Han, Jaemaro; Zhao, Xin; Lee, Jong Keun; Kim, Jae Young

    2014-05-01

    Arsenic compounds are considered carcinogen and easily enter drinking water supplies with their natural abundance. US Environmental Protection Agency is finalizing a regulation to reduce the public health risks from arsenic in drinking water by revising the current drinking water standard for arsenic from 50 ppb to 10 ppb in 2001 (USEPA, 2001). Therefore, soil remediation is also growing field to prevent contamination of groundwater as well as crop cultivation. Soil washing is adjusted as ex-situ soil remediation technique which reduces volume of the contaminated soil. The technique is composed of physical separation and chemical extraction to extract target metal contamination in the soil. Chemical extraction methods have been developed solubilizing contaminants containing reagents such as acids or chelating agents. And acid extraction is proven as the most commonly used technology to treat heavy metals in soil, sediment, and sludge (FRTR, 2007). Due to the unique physical and chemical properties, magnetic iron oxide have been used in diverse areas including information technology and biomedicine. Magnetic iron oxides also can be used as adsorbent to heavy metal enhancing removal efficiency of arsenic concentration. In this study, magnetite is used as the washing agent with acid extraction condition so that the injected oxide can be separated by magnetic field. Soil samples were collected from three separate areas in the Janghang smelter site and energy crops-grown soil to have synergy effect with phytoremediation. Each sample was air-dried and sieved (2mm). Soil washing condition was adjusted on pH in the range of 0-12 with hydrogen chloride and sodium hydroxide. After performing soil washing procedure, arsenic-extracted samples were analyzed for arsenic concentration by inductively coupled plasma optical emission spectrometer (ICP-OES). All the soils have exceeded worrisome level of soil contamination for region 1 (25mg/kg) so the soil remediation techniques are

  14. Effect of straw mulch residues of previous crop oats on the weed population in direct seeded faba bean in Organic Farming

    Directory of Open Access Journals (Sweden)

    Massucati, Luiz Felipe Perrone

    2014-02-01

    Full Text Available Under conditions of Organic Farming, we investigated whether direct seeding of faba bean (Vicia faba L. into straw mulch from residues of precrop oats used for weed control enables at least occasional/opportunistic direct seeding in Organic Agriculture. Eight field trials were carried out at different study sites in North Rhine-Westphalia, Germany, in 2008-2009 and 2009-2010. Direct seeding (DS was performed into mulch layers of 0,4 and 6 t ha-1 of straw residues applied to the remaining stubble, simulating different yield levels of the precrop oats. LBS was used as a reference treatment, where straw was harvested, stubble tillage performed and seedbed prepared in fall and oil radish (Raphanus sativus grown as winter cover crop. Mouldboard ploughing combined with conventional seedbed preparation was performed in early spring to V. faba. Compared with LBS, straw mulch with subsequent direct seeding suppressed especially dicotyledonous annuals significantly. DS treatments with straw reduced the abundance of this group by 81 and 85% compared with LBS. Straw mulch resulted in effective suppression of photosensitive weeds such as Matricaria spp. and late germinating Chenopodium album. Grasses and perennial species occurred independent of the amount of straw. Compared with DS, the abundance of these weeds was reduced by 64 and 82% in LBS treatment. The shoot dry matter production of faba bean was retarded by DS compared with LBS, but significant yield losses could be avoided with straw residues of at least 4 t ha-1. Sufficient amount of straw of from the previous crop is a key criterion to facilitate organic no-till farming of faba bean in a suitable crop sequence when pressure of perennials and grasses is low.

  15. Steam and air co-injection in removing residual TCE in unsaturated layered sandy porous media.

    Science.gov (United States)

    Peng, Sheng; Wang, Ning; Chen, Jiajun

    2013-10-01

    Steam and air co-injection is a promising technique for volatile and semi-volatile organic contaminant remediation in heterogeneous porous media. In this study, removal of trichloroethene (TCE) with steam-air co-injection was investigated through a series of 2D sandbox experiments with different layered sand structures, and through numerical simulations. The results show that a layered structure with coarse sand, in which steam and air convection are relatively rapid, resulted in a higher removal rate and a larger removal ratio than those observed in an experiment using finer sand; however, the difference was not significant, and the removal ratios from three experiments ranged from 85% to 94%. Slight downward movement of TCE was observed for Experiment 1 (TCE initially in a fine sand zone encased in a coarse sand), while no such movement was observed for Experiment 2 (TCE initially in two fine sand layers encased in a coarse sand) or 3 (TCE initially in a silty sand zone encased in a coarse sand). Simulations show accumulation of TCE at the interface of the layered sands, which indicates a capillary barrier effect in restraining the downward movement of TCE. This effect is illustrated further by a numerical experiment with homogeneous coarse sand, in which continuous downward TCE movement to the bottom of the sandbox was simulated. Another numerical experiment with higher water saturation was also conducted. The results illustrate a complicated influence of water saturation on TCE removal in a layered sand structure.

  16. Utilização do nitrogênio (15N residual de coberturas de solo e da uréia pela cultura do milho Utilization of residual nitrogen (15N from cover crop and urea by corn

    Directory of Open Access Journals (Sweden)

    Edson Cabral da Silva

    2006-12-01

    Full Text Available Geralmente, grande parte do N de fertilizantes minerais e de plantas de cobertura de solo não é aproveitada pelo milho no cultivo imediato à aplicação, o qual pode ser absorvido pelas culturas cultivadas subseqüentemente. O objetivo deste trabalho foi avaliar o aproveitamento pelo milho do N residual da uréia, da crotalária (Crotalaria juncea e do milheto (Pennisetum americanum marcados com 15N, aplicados ao milho cultivado em sistema plantio direto, no ano agrícola anterior, num Latossolo Vermelho distroférrico no Cerrado. O estudo foi desenvolvido na fazenda experimental da Faculdade de Engenharia de Ilha Solteira-UNESP, Selvíria (MS, em áreas distintas. O delineamento experimental foi de blocos ao acaso com 15 tratamentos e quatro repetições, aplicados ao milho em 2001/02 e 2002/03. Os tratamentos foram dispostos em esquema fatorial 3 x 5, compreendendo a combinação de três coberturas de solo: crotalária juncea, milheto e vegetação espontânea (pousio, e cinco doses de N-uréia: 0, 30, 80, 130 e 180 kg ha-1. Após a colheita do milho, as duas áreas permaneceram em pousio nas entressafras e, em seguida, cultivadas novamente com milho, safras 2002/03 (experimento 1 e 2003/04 (experimento 2, utilizando adubação similar em todas as parcelas, para distinguir o efeito do N residual. O aproveitamento médio do N residual da parte aérea do milheto e da crotalária pelo milho foi inferior a 3,5 e 3 %, respectivamente, da quantidade inicial. A quantidade de N residual da uréia absorvida pelo milho aumentou de forma quadrática, no experimento 1, e linear, no experimento 2, em relação à dose de N aplicada, sendo o aproveitamento desta inferior a 3 %. As coberturas de solo não influenciaram o aproveitamento pelo milho do N residual da uréia, e vice-versa.The majority of N from mineral fertilizers and cover crops is usually not used by the very next corn crop, but can be absorbed by follow-up crops. The objective of this

  17. A comparative in vitro efficacy of conventional rotatory and chemomechanical caries removal: Influence on cariogenic flora, microhardness, and residual composition

    Directory of Open Access Journals (Sweden)

    Rene Garcia-Contreras

    2014-01-01

    Full Text Available Background: Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation. Materials and Methods: Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37΀C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation. Results: Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001 than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R 2 = 0.683, P < 0.00001 and drilling with burs (R 2 = 0.139, P < 0.00001. Conclusion: The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin.

  18. Monitoring and removal of residual phthalate esters and pharmaceuticals in the drinking water of Kaohsiung City, Taiwan.

    Science.gov (United States)

    Yang, Gordon C C; Yen, Chia-Heng; Wang, Chih-Lung

    2014-07-30

    This study monitored the occurrence and removal efficiencies of 8 phthalate esters (PAEs) and 13 pharmaceuticals present in the drinking water of Kaohsiung City, Taiwan. The simultaneous electrocoagulation and electrofiltration (EC/EF) process was used to remove the contaminants. To this end, a monitoring program was conducted and a novel laboratory-prepared tubular carbon nanofiber/carbon/alumina composite membrane (TCCACM) was incorporated into the EC/EF treatment module (collectively designated as "TCCACM-EC/EF treatment module") to remove the abovementioned compounds from water samples. The monitoring results showed that the concentrations of PAEs were lower in water samples from drinking fountains as compared with tap water samples. No significant differences were found between the concentrations of pharmaceuticals in the two types of water samples. Under optimal operating conditions, the TCCACM-EC/EF treatment module yielded the lowest residual concentrations, ranging from not detected (ND) to 52ng/L for PAEs and pharmaceuticals of concern in the tap water samples. Moreover, the performance of the TCCACM-EC/EF treatment module is comparable with a series of treatment units employed for the drinking fountain water treatment system. The relevant removal mechanisms involved in the TCCACM-EC/EF treatment module were also discussed in this work. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. A comparative in vitro efficacy of conventional rotatory and chemomechanical caries removal: Influence on cariogenic flora, microhardness, and residual composition

    Science.gov (United States)

    Garcia-Contreras, Rene; Scougall-Vilchis, Rogelio Jose; Contreras-Bulnes, Rosalia; Sakagami, Hiroshi; Morales-Luckie, Raul Alberto; Nakajima, Hiroshi

    2014-01-01

    Background: Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation. Materials and Methods: Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37°C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation. Results: Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001) than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R2 = 0.683, P < 0.00001) and drilling with burs (R2 = 0.139, P < 0.00001). Conclusion: The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin. PMID:25506140

  20. Determination of residual dentine caries after conventional mechanical and chemomechanical caries removal with Carisolv.

    Science.gov (United States)

    Splieth, C; Rosin, M; Gellissen, B

    2001-12-01

    The aim of the study was to assess the efficacy of removing dentine caries chemomechanically with Carisolv and with round burs. In 24 extracted permanent teeth each, caries removal with Carisolv or rotating round burs was monitored by checking the hardness of the dentine with a dental explorer and stopped at 12 teeth in each group when either (a) a leather-hard texture was reached or (b) a sharp scratching sound was heard. After embedding and sectioning (400 microm), caries activity of the remaining dentine was assessed using methyl red dye. In microscope images (7x) of the samples, the mean depth of the pink (caries-active, pH5.5) staining of each carious lesion was calculated. Using a round bur, the depth of caries-active and -inactive lesions was significantly greater when a leather-hard texture (51-58 microm) was reached than when a sharp scratching sound was reached (19-25 microm, t-test, Premoval, Carisolv treatment resulted in higher mean depths of caries-active dentine (71-78 microm) than conventional caries removal using the round bur (19-51 microm), while the mean depths of the caries-inactive dentine differed minimally. Thus, caries removal with Carisolv leaves up to a mean of 50 microm more carious dentine than round burs.

  1. Expression of allelopathy in the soil environment: Soil concentration and activity of benzoxazinoid compounds released by rye cover crop residue

    Science.gov (United States)

    The activity of allelopathic compounds is often reduced in the soil environment where processes involving release from donor plant material, soil adsorption and degradation, and uptake by receptor plants naturally result in complex interactions. Rye (Secale cereale L.) cover crops are known to supp...

  2. Preparation and characterization of zirconia-loaded lignocellulosic butanol residue as a biosorbent for phosphate removal from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Enmin [Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000 (China); Liu, Xiaohuan, E-mail: liuxiaohuancaf@163.com [School of Engineering, National Engineering and Technology Research Center of Wood-Based Resources Comprehensive Utilization, and Key Laboratory of Wood Science and Technology of Zhejiang Province, Zhejiang Agriculture and Forestry University, Hangzhou, Lin’an 311300 (China); Jiang, Jinhua [Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000 (China); Fu, Shenyuan [School of Engineering, National Engineering and Technology Research Center of Wood-Based Resources Comprehensive Utilization, and Key Laboratory of Wood Science and Technology of Zhejiang Province, Zhejiang Agriculture and Forestry University, Hangzhou, Lin’an 311300 (China); Chu, Fuxiang [Institute of Chemical Industry of Forestry Products, CAF, Nanjing 210037 (China)

    2016-11-30

    Highlights: • LBR-Zr was evaluated as a novel biosorbent for phosphate removal. • Effects of process factors on phosphate adsorption were studied in detail. • LBR-Zr showed markedly enhanced phosphate adsorption compared to LBR. • The underlying mechanism for phosphate adsorption of LBR-Zr was fully investigated. - Abstract: Zirconium(IV) loaded lignocellulosic butanol residue (LBR-Zr) used for the adsorption of phosphate (P) ions from aqueous solution was synthesized and evaluated. The adsorption isotherms were fitted well with the Freundlich and Temkin modes. Thermodynamic analyses indicated that phosphate adsorption on the LBR-Zr increased with increasing temperature from 298 to 338 K. The kinetic datas were described better by the pseudo-second-order adsorption kinetic rate model. Increasing pH suppressed phosphate adsorption. Coexisting anions study exhibited that the incorporation of CO{sub 3}{sup 2−} anion had the largest influence on the phosphate adsorption capacity. The mechanism of adsorption process on LBR-Zr was analyzed by FTIR (Fourier transform infrared spectroscopy), scanning electron microscope (SEM) with an EDX (energy dispersive X-ray) and X-ray photoelectron spectroscopy (XPS) technologies, respectively. The above results confirmed that surface hydroxyl groups on biosorbent LBR-Zr were replaced by phosphate. The LBR-Zr with good specific affinity towards phosphate was a promising biosorbent for phosphate removal from aqueous solution. The research would be beneficial for developing a promising, eco-friendly phosphate biosorbent from plentiful lignocellulosic butanol residue.

  3. Neonicotinoid insecticide residues in soil dust and associated parent soil in fields with a history of seed treatment use on crops in southwestern Ontario.

    Science.gov (United States)

    Limay-Rios, Victor; Forero, Luis Gabriel; Xue, Yingen; Smith, Jocelyn; Baute, Tracey; Schaafsma, Arthur

    2016-02-01

    Using neonicotinoid insecticides as seed treatments is a common practice in field crop production. Exposure of nontarget organisms to neonicotinoids present in various environmental matrices is debated. In the present study, concentrations of neonicotinoid residues were measured in the top 5 cm of soil and overlying soil surface dust before planting in 25 commercial fields with a history of neonicotinoid seed treatment use in southwestern Ontario in 2013 and 2014 using liquid chromatography-electrospray ionization tandem mass spectrometry. The mean total concentrations were 3.05 ng/g and 47.84 ng/g in 2013 and 5.59 ng/g and 71.17 ng/g in 2014 for parent soil and soil surface dust, respectively. When surface and parent soil residues were compared the mean concentration in surface dust was 15.6-fold and 12.7-fold higher than that in parent soil in 2013 and 2014, respectively. Pooled over years, the surface dust to parent soil ratio was 13.7, with mean concentrations of 4.36 ng/g and 59.86 ng/g for parent soil and surface dust, respectively. The present study's results will contribute important knowledge about the role these residues may play in the overall risk assessment currently under way for the source, transport, and impact of neonicotinoid insecticide residues in a maize ecosystem.

  4. Peering through the OH-forest: a new technique to remove residual sky features from SDSS spectra

    CERN Document Server

    Wild, V; Wild, Vivienne; Hewett, Paul C.

    2005-01-01

    The Sloan Digital Sky Survey (SDSS) currently provides by far the largest homogeneous sample of intermediate signal-to-noise ratio (S/N) optical spectra of galaxies and quasars. The fully automated SDSS spectroscopic reduction pipeline has provided spectra of unprecedented quality that cover the wavelength range 3800-9200A. However, in common with spectra from virtually all multi-object surveys employing fibres, there remain significant systematic residuals in many of the spectra due to the incomplete subtraction of the strong OH sky emission lines longward of 6700A. The S/N over substantial wavelength regions in many spectra is reduced by more than a factor of 2 over that expected from counting statistics. We present a method to automatically remove the sky residual signal, using a principal component analysis (PCA) which takes advantage of the correlation in the form of the sky subtraction residuals present in each spectrum. Application of the method results in spectra with essentially no evidence for degra...

  5. Composites based on PET and red mud residues as catalyst for organic removal from water

    Energy Technology Data Exchange (ETDEWEB)

    Bento, Natálya I.; Santos, Patrícia S.C. [Science and Technology Institute, Federal University of Alfenas, Rodovia José Aurélio Vilela, 11999, BR 267, Km 533, CEP 37715-400 Poços de Caldas, MG (Brazil); Souza, Talita E. de; Oliveira, Luiz C.A. [Department of Chemistry, Federal University of Minas Gerais, UFMG, Av. Antônio Carlos, 6627, Pampulha, 31270-901 Belo Horizonte, MG (Brazil); Castro, Cínthia S., E-mail: cinthia.soares.castro@gmail.com [Science and Technology Institute, Federal University of Alfenas, Rodovia José Aurélio Vilela, 11999, BR 267, Km 533, CEP 37715-400 Poços de Caldas, MG (Brazil)

    2016-08-15

    Highlights: • Composite based on carbon/iron oxide from PET and red mud wastes for organic contaminants oxidation. • Composites are mainly composed of hematite and a carbon matrix from PET decomposition. • RM/PET-15 presents the highest methylene blue (MB) removal from water, by combined adsorption and oxidation processes. • The dye oxidation was confirmed by ESI-MS studies. • The RM/PET catalysts can be reused for at least four batch runs. - Abstract: In this study, we obtained a composite based on carbon/iron oxide from red mud and PET (poly(ethylene terephthalate)) wastes by mechanical mixture (10, 15 and 20 wt.% of PET powder/red mud) followed by a controlled thermal treatment at 400 °C under air. XRD analyses revealed that the α-Fe{sub 2}O{sub 3} is the main phase formed from red mud. TPR analyses showed that the iron oxide present in the composites undergoes reduction at lower temperature to form Fe{sup 2+} species present in Fe{sub 3}O{sub 4}, indicating that the iron oxide in the composite can exhibit greater reactivity in the catalytic processes compared to the original red mud. In fact, catalytic tests showed that the composites presented higher capacity to remove methylene blue dye (MB), presenting about 90% of removal after 24 h of reaction. The MB removal was also monitored by mass spectrometer with ionization via electrospray (ESI-MS), which demonstrated the occurrence of the oxidation process, showing the formation of MB oxidation products. The stability of the composites was confirmed after four reuse cycles. The results seem to indicate that PET carbon deposited over the iron oxide from red mud promotes adsorption of the contaminant allowing its contact with the iron atoms and their consequent reaction.

  6. Removal of uranyl ions from residual waters using some algae types

    Science.gov (United States)

    Cecal, Al; Palamaru, I.; Humelnicu, D.; Popa, K.; Salaru, V. V.; Rudic, V.; Gulea, A.

    1999-01-01

    This paper deals with a study on the bioaccumulation of uranyl ions resulted from residual effluents by means of some microbiological collectors: Scenedesmus quadricauda, Anabaena karakumica, Calothrix brevissima, Penicillinium sp, as well as the Glucide extract of Porphyridium cruentum, under various experimental conditions. The retaining degree of the bioaccumulated uranyl ions, as well as the leaching degree, in HCl and H2O media, of the same ions previously retained on algae were established. The retaining degree decreases in the serie: Scenedesmus quadricauda >Anabaena karakumica >Penicillinium sp>Calothrix brevissima. The leaching effect of bioaccumulated uranyl ions is higher in hydrochloric acid than in water.

  7. Composites based on PET and red mud residues as catalyst for organic removal from water.

    Science.gov (United States)

    Bento, Natálya I; Santos, Patrícia S C; de Souza, Talita E; Oliveira, Luiz C A; Castro, Cínthia S

    2016-08-15

    In this study, we obtained a composite based on carbon/iron oxide from red mud and PET (poly(ethylene terephthalate)) wastes by mechanical mixture (10, 15 and 20wt.% of PET powder/red mud) followed by a controlled thermal treatment at 400°C under air. XRD analyses revealed that the α-Fe2O3 is the main phase formed from red mud. TPR analyses showed that the iron oxide present in the composites undergoes reduction at lower temperature to form Fe(2+) species present in Fe3O4, indicating that the iron oxide in the composite can exhibit greater reactivity in the catalytic processes compared to the original red mud. In fact, catalytic tests showed that the composites presented higher capacity to remove methylene blue dye (MB), presenting about 90% of removal after 24h of reaction. The MB removal was also monitored by mass spectrometer with ionization via electrospray (ESI-MS), which demonstrated the occurrence of the oxidation process, showing the formation of MB oxidation products. The stability of the composites was confirmed after four reuse cycles. The results seem to indicate that PET carbon deposited over the iron oxide from red mud promotes adsorption of the contaminant allowing its contact with the iron atoms and their consequent reaction.

  8. Present Situation and Control Countermeasures of Pesticide Residue on Crops in Yinzhou District of Ningbo City, China

    Directory of Open Access Journals (Sweden)

    XU Pei-juan

    2014-02-01

    Full Text Available Tatal of 411 batches of rice, leaf vegetables, fruits, beans, solanums and tubers were sampled monthly, in accordance with related national regulations on 22 detected pesticides in the Yinzhou District, Ningbo City. The results showed that the pesticide detection rate was0.3%, the qualified rate of pesticide residues in agricultural products was 97.82%. Pesticide residues detection accounted for 88.89%. The samples beyond the pesticide residue standard were mainly vegetables from May to October. Leaf vegetables exceeding the standard sample rate reached 3.72%. Pesticide residue samples exceeding the standard were found in retail in plain and coastal areas, but were found in all scale farming in mountainous areas. The rate of exceeding the pesticide residues standard of farmers with primary school education level was4.50%, which was 6.16 times higher than that farmers with university education. In order to reduce the pesticide residual in Yinzhou District,we put forward control countermeasures in 5 aspects.

  9. A transcriptomic analysis of Neurospora crassa using five major crop residues and the novel role of the sporulation regulator rca-1 in lignocellulase production.

    Science.gov (United States)

    Wang, Bang; Cai, Pengli; Sun, Wenliang; Li, Jingen; Tian, Chaoguang; Ma, Yanhe

    2015-01-01

    Crop residue is an abundant, low-cost plant biomass material available worldwide for use in the microbial production of enzymes, biofuels, and valuable chemicals. However, the diverse chemical composition and complex structure of crop residues are more challenging for efficient degradation by microbes than are homogeneous polysaccharides. In this study, the transcriptional responses of Neurospora crassa to various plant straws were analyzed using RNA-Seq, and novel beneficial factors for biomass-induced enzyme production were evaluated. Comparative transcriptional profiling of N. crassa grown on five major crop straws of China (barley, corn, rice, soybean, and wheat straws) revealed a highly overlapping group of 430 genes, the biomass commonly induced core set (BICS). A large proportion of induced carbohydrate-active enzyme (CAZy) genes (82 out of 113) were also conserved across the five plant straws. Excluding 178 genes within the BICS that were also upregulated under no-carbon conditions, the remaining 252 genes were defined as the biomass regulon (BR). Interestingly, 88 genes were only induced by plant biomass and not by three individual polysaccharides (Avicel, xylan, and pectin); these were denoted as the biomass unique set (BUS). Deletion of one BUS gene, the transcriptional regulator rca-1, significantly improved lignocellulase production using plant biomass as the sole carbon source, possibly functioning via de-repression of the regulator clr-2. Thus, this result suggests that rca-1 is a potential engineering target for biorefineries, especially for plant biomass direct microbial conversion processes. Transcriptional profiling revealed a large core response to different sources of plant biomass in N. crassa. The sporulation regulator rca-1 was identified as beneficial for biomass-based enzyme production.

  10. Reuse of drinking water treatment residuals in a continuous stirred tank reactor for phosphate removal from urban wastewater.

    Science.gov (United States)

    Bai, Leilei; Wang, Changhui; Pei, Yuansheng; Zhao, Jinbo

    2014-01-01

    This work proposed a new approach of reusing drinking water treatment residuals (WTR) in a continuous stirred tank reactor (CSTR) to remove phosphate (P) from urban wastewater. The results revealed that the P removal efficiency of the WTR was more than 94% for urban wastewater, in the condition of initial P concentration (P0) of 10 mg L⁻¹, hydraulic retention time (HRT) of 2 h and WTR dosage (M0) of 10 g L⁻¹. The P mass transfer from the bulk to the solid-liquid interface in the CSTR system increased at lower P0, higher M0 and longer HRT. The P adsorption capacity of WTR from urban wastewater was comparable to that of the 201 × 4 resin and unaffected by ions competition. Moreover, WTR had a limited effect on the metals' (Fe, Al, Zn, Cu, Mn and Ni) concentrations of the urban wastewater. Based on the principle of waste recycling, the reuse of WTR in CSTR is a promising alternative technology for P removal from urban wastewater.

  11. Moringa Seed, Residual Coffee Powder, and Banana Peel as Biosorbents for Uranium Removal from Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Marcelo L. Garcia

    2017-03-01

    Full Text Available The uranium mining deserves attention with regard to environmental impacts and water pollution in Brazil. The research objective was to enable the use of biomass as cheap and available adsorbents for uranium removal from acid mine drainage. Three types of biomass were tested: banana peel, residual coffee powder, and moringa seed. Synthetic uranium solution (SS and acid mine drainage (AMD were used in the equilibrium adsorption experiments. Remarkable total uranium removal efficiencies were observed for moringa (96.8 ± 2.2 [SS] and 86.5 ± 0.8% [AMD], coffee (89.4 ± 11.2 [SS] and 73.7 ± 2.2% [AMD], and banana (48.2 ± 14.0 [SS] and 55.9 ± 4.8% [AMD]. The highest experimental adsorption densities were 18.7, 19.1, and 6.3 mg∙g-1 , respectively. Quantitative curves were described for each adsorbent and can be used for practical applications. Design and operating parameters for uranium removal from AMD as a post-treatment, polishing method can be determined beforehand.

  12. Removal and recovery of nutrients as struvite from anaerobic digestion residues of poultry manure.

    Science.gov (United States)

    Yilmazel, Y D; Demirer, G N

    2011-01-01

    The removal and the recovery of nutrients, namely nitrogen (N) and phosphorus (P) from anaerobically digested and solid-liquid separated manure effluents via struvite precipitation were investigated. Both the liquid and the solid phases of the poultry manure digester effluent were subjected to struvite precipitation experiments. The Mg:N:P molar ratio of 1:1:1 in the liquid phase resulted in an average NH4-N removal efficiency of 86.4%, which increased to 97.4% by adjusting the Mg:N:P ratio to 1.5:1:1. The acidic phosphorus-dissolution process was applied to the solid phase of the effluent to obtain a phosphorus-enriched solution. Nutrient recovery experiments with NaOH as the buffering reagent were conducted with and without addition of external chemicals (Mg and P sources) to evaluate the influence of the Mg:N:P molar ratio, the Mg:P molar ratio and pH. All the experiments depicted complete PO4-P (99.6-100.0%) and partial NH4-N (3.3-65.6%) recoveries from the phosphorus-enriched solution.

  13. Conversion of agricultural residues into activated carbons for water purification: Application to arsenate removal.

    Science.gov (United States)

    Torres-Perez, Jonatan; Gerente, Claire; Andres, Yves

    2012-01-01

    The conversion of two agricultural wastes, sugar beet pulp and peanut hulls, into sustainable activated carbons is presented and their potential application for the treatment of arsenate solution is investigated. A direct and physical activation is selected as well as a simple chemical treatment of the adsorbents. The material properties, such as BET surface areas, porous volumes, elemental analysis, ash contents and pH(PZC), of these alternative carbonaceous porous materials are determined and compared with a commercial granular activated carbon. An adsorption study based on experimental kinetic and equilibrium data is conducted in a batch reactor and completed by the use of different models (intraparticle diffusion, pseudo-second-order, Langmuir and Freundlich) and by isotherms carried out in natural waters. It is thus demonstrated that sugar beet pulp and peanut hulls are good precursors to obtain activated carbons for arsenate removal.

  14. A pilot plant for removing chromium from residual water of tanneries.

    Science.gov (United States)

    Landgrave, J

    1995-02-01

    The purpose of this study is to develop a technical process for removing trivalent chromium from tannery wastewater via precipitation. This process can be considered an alternative that avoids a remediation procedure against the metal presence in industrial wastes. This process was verified in a treatment pilot plant located in León, México handling 10 m3/day of three types of effluents. The effluent streams were separated to facilitate the elimination of pollutants from each one. The process was based on in situ treatment and recycle to reduce problems associated with transportation and confinement of contaminated sludges. Two types of treatment were carried out in the pilot plant: The physical/chemical and biological treatments. Thirty-five experiments were conducted and the studied variables were the pH, type of flocculant, and its dose. The statistical significance of chromium samples was 94.7% for its precipitation and 99.7% for recovery. The objectives established for this phase of the development were accomplished and the overall efficiencies were measured for each stage in the pilot plant. The results were: a) chromium precipitation 99.5% from wastewater stream, b) chromium recovery 99% for recycling, and c) physical/chemical treatment to eliminate grease and fat at least 85% and 65 to 70% for the biological treatment. The tanning of a hide lot (350 pieces) was accomplished using 60% treated and recycled water without affecting the product quality. The recovered chromium liquor was also used in this hide tanning. This technical procedure is also applicable for removing heavy metals in other industrial sectors as well as in reducing water consumption rates, if pertinent adjustments are implemented.

  15. Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling

    DEFF Research Database (Denmark)

    Li, Xiaoxi; Sørensen, Peter; Li, F C

    2015-01-01

    Contributions of legume-based catch crops (LBCCs) to succeeding cereals may be significant. We quantified biological N fixation (BNF) and residual N effects of contrasting CC tops and roots. Methods BNF of three LBCCs (red clover, winter vetch, perennial ryegrass-red clover mixture) was quantified...... in microplots by 15N labelling. Their residual effects on spring barley were tested against two non-LBCCs (perennial ryegrass, fodder radish) after spring incorporation of CC tops or roots in monoliths. Total N accumulated in LBCCs was 153–226 kg N ha−1, of which 62–66 % was derived from BNF in tops and 31......–46 % in macro-roots (0–18 cm soil). Macro-roots represented 31–50 % of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50 kg N fertilisation ha−1, whereas no extra...

  16. ZnCl2-activated biochar from biogas residue facilitates aqueous As(III) removal

    Science.gov (United States)

    Xia, Dong; Tan, Fen; Zhang, Chuanpan; Jiang, Xiuli; Chen, Zheng; Li, Heng; Zheng, Yanmei; Li, Qingbiao; Wang, Yuanpeng

    2016-07-01

    Biochars prepared from biogas residue using different chemical activators were investigated for their As(III) adsorption properties. The results indicated that the original biochars did not exhibit significant As(III) adsorption. However, ZnCl2-activated biochar, which possessed the largest specific surface area, 516.67 cm2/g, and exhibited a perfectly porous texture, showed excellent performance in a 500 μgL-1 solution of As(III). Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy were utilized to identify the mechanism of As(III) adsorption by ZnCl2-activated biochar. Adsorption was found to occur mainly through ligand exchange of the hydroxyl in Zn-OH to form Zn-O-As(III), as well as through porous adsorption. As a low-cost adsorbent, the adsorption process was well fitted using a pseudo-second-order model, with an R2 > 0.993. The adsorption process was fast, requiring nearly 90 min to reach adsorption equilibrium. Batch adsorption experimental results indicated that ZnCl2-activated biochar has a maximum adsorption capacity of 27.67 mg/g at pH 7.0, and the adsorption process followed the Freundlich isotherm model well, with an R2 > 0.994. In addition, the current work demonstrated the efficiency of using ZnCl2-activated biochar adsorbent to treat As(III)-contaminated water.

  17. Removal of phenol by powdered activated carbon prepared from coal gasification tar residue.

    Science.gov (United States)

    Wang, Xiong-Lei; Shen, Jun; Niu, Yan-Xia; Wang, Yu-Gao; Liu, Gang; Sheng, Qing-Tao

    2017-04-10

    Coal gasification tar residue (CGTR) is a kind of environmentally hazardous byproduct generated in fixed-bed coal gasification process. The CGTR extracted by ethyl acetate was used to prepare powdered activated carbon (PAC), which is applied later for adsorption of phenol. The results showed that the PAC prepared under optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with a specific surface area of 1981 m(2)/g and a total pore volume of 0.92 ml/g. Especially, without loading other substances, the PAC, having a strong magnetism, can be easily separated after it adsorbs phenol. The adsorption of phenol by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed a fast adsorption speed and a high adsorption capacity of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo-second-order model. These results show that CGTR can be used as a potential adsorbent of phenols in wastewater.

  18. Influence of residue and nitrogen fertilizer additions on carbon mineralization in soils with different texture and cropping histories

    Science.gov (United States)

    To improve our ability to predict SOC mineralization response to residue and N additions in soils with different inherent and dynamic organic matter properties, a 330-day incubation was conducted using soil sampled from two long-term experiments (clay loam Mollisols in Iowa [IAsoil] and silt loam Ul...

  19. Viimsi water treatment plant for Ra removal: NORM residue/waste generation, radiation safety issues, and regulatory response

    Energy Technology Data Exchange (ETDEWEB)

    Kiisk, M.; Suursoo, S.; Realo, E.; Jantsikene, A.; Lumiste, L.; Vaeaer, K.; Isakar, K.; Koch, R. [University of Tartu (Estonia)

    2014-07-01

    In early 2012, the first large-scale water treatment plant, specifically designed to remove Ra-isotopes from groundwater, was commissioned in Viimsi parish, North-Estonia. The plant serves approximately 15 000 consumers with maximum production capacity of 6000 m{sup 3}/d. The chosen water treatment technology is chemical free and is based on co-precipitation and adsorption with Fe(OH){sub 3} and MnO{sub 2} flocks, and adsorption of residual Ra onto zeolite sand. The chosen technology is a complex approach and is designed to reduce high Fe and Mn concentrations as well as dissolved gases along with Ra isotopes. It is proved to be well adapted with hydro-chemical conditions of the groundwater feeding the plant. As the novel technology has been applied for the first time on a large scale, the plant was taken under long-term investigation when commissioned. The latter focuses on three areas: Ra removal efficiency and its dynamics, build-up of radioactive waste, and radiation safety. The average Ra-226 and Ra-228 activity concentrations in raw water feeding the plant are approximately 0.5 Bq/L and 0.6 Bq/L, respectively, resulting in total indicative dose of 0.4 mSv/y. Operating conditions of the plant are restricted by the established indicative value of 0.1 mSv/y for drinking water, i.e. a minimum 75% removal efficiency for Ra is required. Results of the studies show that the plant operates at Ra-removal efficiency of 98% or higher without the need of regeneration or replacement of filtering materials within the first two years. Measurements confirm that ∼90% of Ra accumulates in the solid filter media, 8-9% is washed out by backwash system as liquid effluent and 1-2% is fed on to the consumer distribution network. It has been calculated that at the level of current production capacity (below 3000 m{sup 3}/d) the yearly accumulation rate in the plant is approximately 300 and 400 MBq/y for Ra-226 and Ra-228, respectively. These values strongly exceed the exemption

  20. The development and verification of thermal-hydraulic code on passive residual heat removal system of Chinese advanced PWR

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The technology of passive safety is the current trend among safety systems in nuclear power plant. Passive residual heat removal system (PRHRS), a major part of passive safety systems of Chinese advanced PWR, is a novel design with three-fold natural circulation. On the basis of reasonable physics and mathematics models, MITAP-PRHRS code was developed to analyze steady and transient characteristics of the PRHRS. The calculation and analysis show that the code simulates steady characteristics of the PRHRS very well, and it is able to simulate transient characteristics of all startup modes of the PRHRS. However, the quantitative description is poor during the initial stages of the transition process when water hammer occurs.

  1. Carbonaceous material production from vegetable residue and their use in the removal of textile dyes present in wastewater

    Science.gov (United States)

    Peláez-Cid, A. A.; Tlalpa-Galán, M. A.; Herrera-González, A. M.

    2013-06-01

    This paper presents the adsorption results of acid, basic, direct, vat, and reactive-type dyes on carbonaceous adsorbent materials prepared starting off vegetable residue such as Opuntia ficus indica and Casimiroa edulis fruit wastes. The adsorbents prepared from Opuntia ficus indica waste were designated: TunaAsh, CarTunaT, and CarTunaQ. The materials obtained from Casimiroa edulis waste were named: CenZAP, CarZAPT, and CarZAPQ. TunaAsh and CenZAP consist of ashes obtained at 550 °C CarTunaT and CarZAPT consist of the materials carbonized at 400 °C lastly, CarTunaQ and CarZAPQ consist of chemically activated carbons using H3PO4 at 400 °C. Only the chemically activated materials were washed with distilled water until a neutral pH was obtained after their carbonization. All materials were ground and sieved to obtain a particle size ranging from 0.25 to 0.84 mm. The static adsorption results showed that both ashes and chemically activated carbon are more efficient at dye removal for both vegetable residues. For TunaAsh and CarTunaQ, removal rates of up to 100% in the cases of basic, acid, and direct dyes were achieved. Regarding wastewater containing reactive dyes, the efficiency ranged from 60 to 100%. For vat effluents, it ranged from 42 to 52%. In the case of CenZAP and CarZAPQ, it was possible to treat reactive effluents with rates ranging between 63 and 91%. Regarding vat effluents, it ranged from 57 to 68%. The process of characterization for all materials was done using scanning electron microscopy and infrared spectroscopy.

  2. Preparation and characterization of zirconia-loaded lignocellulosic butanol residue as a biosorbent for phosphate removal from aqueous solution

    Science.gov (United States)

    Zong, Enmin; Liu, Xiaohuan; Jiang, Jinhua; Fu, Shenyuan; Chu, Fuxiang

    2016-11-01

    Zirconium(IV) loaded lignocellulosic butanol residue (LBR-Zr) used for the adsorption of phosphate (P) ions from aqueous solution was synthesized and evaluated. The adsorption isotherms were fitted well with the Freundlich and Temkin modes. Thermodynamic analyses indicated that phosphate adsorption on the LBR-Zr increased with increasing temperature from 298 to 338 K. The kinetic datas were described better by the pseudo-second-order adsorption kinetic rate model. Increasing pH suppressed phosphate adsorption. Coexisting anions study exhibited that the incorporation of CO32- anion had the largest influence on the phosphate adsorption capacity. The mechanism of adsorption process on LBR-Zr was analyzed by FTIR (Fourier transform infrared spectroscopy), scanning electron microscope (SEM) with an EDX (energy dispersive X-ray) and X-ray photoelectron spectroscopy (XPS) technologies, respectively. The above results confirmed that surface hydroxyl groups on biosorbent LBR-Zr were replaced by phosphate. The LBR-Zr with good specific affinity towards phosphate was a promising biosorbent for phosphate removal from aqueous solution. The research would be beneficial for developing a promising, eco-friendly phosphate biosorbent from plentiful lignocellulosic butanol residue.

  3. Copper(II) and lead(II) removal from aqueous solution by water treatment residues.

    Science.gov (United States)

    Castaldi, Paola; Silvetti, Margherita; Garau, Giovanni; Demurtas, Daniela; Deiana, Salvatore

    2015-01-01

    In this study, we investigated the ability of Fe- and Al-based water treatment residues (Fe- and Al-WTR) to accumulate Pb(II) and Cu(II) at pH 4.5. The role of the inorganic and organic fractions of WTRs in metals sorption was also assessed. Sorption isotherms showed a higher sorption of Pb(II) by both WTRs with respect to Cu(II) (e.g. 0.105 and 0.089 mmol g(-1) of Pb(II) and Cu(II) respectively sorbed by Fe-WTR). Fe-WTR revealed a stronger sorbent for both metals than Al-WTR. The amount of Pb(II) and Cu(II) sorbed by Fe-WTR was about the 69% and 63% higher than that sorbed by the Al-WTR. The organic matter of Fe- and Al-WTR contributed to about 26% and 8.5% respectively in the sorption of both metals. The sequential extraction procedure showed that the greatest amount of metals sorbed by both WTRs were tightly bound and not extractable, and this was particularly apparent for Cu(II). The FT-IR spectra indicated the formation of inner-sphere complexes between the Fe(Al)-O nucleus and Pb(II) and Cu(II). Moreover, the FT-IR spectra also suggested that the humic fraction of WTRs interacted, through the carboxylate groups, with Cu(II) and Pb(II) by forming mainly monodentate and bidentate complexes, respectively.

  4. Four Hypotheses to Explain Axillary Budbreak after Removal of Flower Shoots in a Cut-rose Crop

    NARCIS (Netherlands)

    Wubs-Timmermans, A.M.; Heuvelink, E.; Marcelis, L.F.M.; Okello, R.C.; Buck-Sorlin, G.H.; Vos, J.

    2013-01-01

    When flower-bearing shoots in cut-rose (Rosa ×hybrida) are harvested (removed), a varying number of repressed axillary buds on the shoot remainder start to grow into new shoots (budbreak). Besides removing within-shoot correlative inhibition, it is hypothesized that shoot removal leads to 1) increas

  5. Minor crops for export: a case study of boscalid, pyraclostrobin, lufenuron and lambda-cyhalothrin residue levels on green beans and spring onions in Egypt.

    Science.gov (United States)

    Hanafi, Ahmad; Garau, Vincenzo L; Caboni, Pierluigi; Sarais, Giorgia; Cabras, Paolo

    2010-08-01

    Dissipation rates of boscalid [2-chloro-N-(4' -chlorobiphenyl-2-yl)nicotinamide], pyraclostrobin [methyl 2-[1-(4-chlorophenyl) pyrazol-3-yloxymethyl]-N-methoxycarbanilate], lufenuron [(RS)-1-[2,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea] and lambda-cyhalothrin [(R)-cyano(3-phenoxyphenyl)methyl (1S,3S)-rel-3-[(1Z)-2-chloro-3,3,3-trifluoro-1-propenyl]-2,2-dimethylcyclopropanecarboxylate] in green beans and spring onions under Egyptian field conditions were studied. Field trials were carried out in 2008 in a Blue Nile farm, located at 70 kilometer (km) from Cairo (Egypt). The pesticides were sprayed at the recommended rate and samples were collected at pre-determined intervals. After treatment (T(0)) the pesticide residues in green beans were 7 times lower than in spring onions. This is due to a different structure of vegetable plant in the two crops. In spring onions, half-life (t(1/2)) of pyraclostrobin and lufenuron was 3.1 days and 9.8 days respectively. At day 14th (T(14)) after treatment boscalid residues were below the Maximum Residue Limit (MRL) (0.34 versus 0.5 mg/kg), pyraclostrobin and lambda -cyhalothrin residues were not detectable (ND), while lufenuron residues were above the MRL (0.06 versus 0.02 mg/kg). In green beans, at T(0), levels of boscalid, lufenuron and lambda -cyhalothrin were below the MRL (0.28 versus 2 mg/kg; ND versus 0.02 mg/kg; 0.06 versus 0.2 mg/kg, respectively) while, after 7 days treatment (T(7)) pyraclostrobin residues were above the MRL (0.03 versus 0.02 mg/kg). However, after 14 days the residue level could go below the MRL (0.02 mg/kg), as observed in spring onions.

  6. Ammonium Removal from Landfill Leachate by Means of Multiple Recycling of Struvite Residues Obtained through Acid Decomposition

    Directory of Open Access Journals (Sweden)

    Alessio Siciliano

    2016-11-01

    Full Text Available The treatment of landfill leachate, due to its great polluting load, is a very difficult task. In particular, the abatement of high ammonium concentrations represents one of the main issues. Among the available techniques, struvite precipitation is an effective method for the removal and recovery of NH4+ load. However, due to the lack of phosphorus and magnesium amounts, the struvite formation results in an expensive process in the leachate treatment. To overcome this issue, in the present work, we developed a simple and suitable method for ammonium removal by the multiple recycling of struvite decomposition residues. In this regard, a procedure for acid dissolution of struvite, produced by using industrial grade reagents, was initially defined. The effect of pH, temperature, and acid type was investigated. The experimental results proved the effectiveness of both hydrochloric and acetic acid, which allow a high and selective release of ammonium at T = 50 °C and pH = 5.5. The multiple reuse of decomposition products, combined with the supplementation of a small quantity of phosphorus and magnesium at molar ratios of n(N:n(Mg:n(P = 1:0.05:0.05, guarantees stable NH4+ abatement of about 82%. The proposed process allows a cost saving of around to 74% and can be easily applied in industrial treatment plants.

  7. Removal of mixed heavy metal ions in wastewater by zeolite 4A and residual products from recycled coal fly ash.

    Science.gov (United States)

    Hui, K S; Chao, C Y H; Kot, S C

    2005-12-09

    The removal performance and the selectivity sequence of mixed metal ions (Co(2+), Cr(3+), Cu(2+), Zn(2+) and Ni(2+)) in aqueous solution were investigated by adsorption process on pure and chamfered-edge zeolite 4A prepared from coal fly ash (CFA), commercial grade zeolite 4A and the residual products recycled from CFA. The pure zeolite 4A (prepared from CFA) was synthesized under a novel temperature step-change method with reduced synthesis time. Batch method was employed to study the influential parameters such as initial metal ions concentration, adsorbent dose, contact time and initial pH of the solution on the adsorption process. The experimental data were well fitted by the pseudo-second-order kinetics model (for Co(2+), Cr(3+), Cu(2+) and Zn(2+) ions) and the pseudo-first-order kinetics model (for Ni(2+) ions). The equilibrium data were well fitted by the Langmuir model and showed the affinity order: Cu(2+) > Cr(3+) > Zn(2+) > Co(2+) > Ni(2+) (CFA prepared and commercial grade zeolite 4A). The adsorption process was found to be pH and concentration dependent. The sorption rate and sorption capacity of metal ions could be significantly improved by increasing pH value. The removal mechanism of metal ions was by adsorption and ion exchange processes. Compared to commercial grade zeolite 4A, the CFA prepared adsorbents could be alternative materials for the treatment of wastewater.

  8. Th Effct of Silver Nano-Particles on Removing Klebsiella pneumoniae from Industrial Residues

    Directory of Open Access Journals (Sweden)

    Habibipour R

    2017-03-01

    Full Text Available Introduction: Progress in nano-science and nanotechnology in the past decade has provided many opportunities to study the biological effcts of nanoparticles, in particular their anti-bacterial effcts. Th aim of this study was to evaluate the antimicrobial properties of silver nanoparticles for the removal of Klebsiella pneumoniae isolated from industrial efflnts. Methods: In this experimental study, aftr sampling polluted industries, coliform and total coliform measurements of fecal industrial wastewater microbiology were performed by standard methods. Th antimicrobial activity of silver nanoparticles on the bacteria (Klebsiella pneumoniae isolates and standard was evaluated with the agar dilution method and broth dilution. One milliliter suspension containing bacteria at 1.5 × 108 CFU/ mL was added to each sample followed by incubation at 37°C for 24 hours. Aftr the mentioned period, the optical density at a wavelength of 600 nm was used to measure the concentration of bacteria. Next, 100 mL of each dilution was transferred to solid medium followed by incubation. Th results were analyzed with SPSS 22 softare. Results: Fecal and total coliform bacteria pollution of textile wastewater was approved, and Klebsiella pneumoniae (textile industry pollution index were isolated. With increasing concentration, the antibacterial activity of silver nanoparticles increased while the number of colonies decreased. Although none of the concentrations were able to eliminate the bacteria, a non-signifiant decrease in the number of bacteria was observed. Conclusion: Th results of the study showed that the type of bacteria and concentrations of silver nanoparticles antimicrobial properties of silver nanoparticles are risk factors. Although the concentrations used were effctive against bacteria yet they did not lead to complete elimination of bacteria Threfore potential impact of nanoparticles for use requires further research and economic factors and other

  9. Exploration of a mechanism for the production of highly unsaturated fatty acids in Scenedesmus sp. at low temperature grown on oil crop residue based medium.

    Science.gov (United States)

    Lu, Qian; Li, Jun; Wang, Jinghan; Li, Kun; Li, Jingjing; Han, Pei; Chen, Paul; Zhou, Wenguang

    2017-11-01

    The ability of algae to produce lipids comprising of unsaturated fatty acids varies with strains and culture conditions. This study investigates the effect of temperature on the production of unsaturated fatty acids in Scenedesmus sp. grown on oil crop residue based medium. At low temperature (10°C), synthesis of lipids compromising of high contents of unsaturated fatty acids took place primarily in the early stage while protein accumulation mainly occurred in the late stage. This stepwise lipid-protein synthesis process was found to be associated with the contents of acetyl-CoA and α-KG in the algal cells. A mechanism was proposed and tested through simulation experiments which quantified the carbon flux allocation in algal cells at different cultivation stages. It is concluded that low culture temperature such as 10°C is suitable for the production of lipids comprising of unsaturated fatty acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Dry Matter Production, Nutrient Cycled and Removed, and Soil Fertility Changes in Yam-Based Cropping Systems with Herbaceous Legumes in the Guinea-Sudan Zone of Benin.

    Science.gov (United States)

    Maliki, Raphiou; Sinsin, Brice; Floquet, Anne; Cornet, Denis; Malezieux, Eric; Vernier, Philippe

    2016-01-01

    Traditional yam-based cropping systems (shifting cultivation, slash-and-burn, and short fallow) often result in deforestation and soil nutrient depletion. The objective of this study was to determine the impact of yam-based systems with herbaceous legumes on dry matter (DM) production (tubers, shoots), nutrients removed and recycled, and the soil fertility changes. We compared smallholders' traditional systems (1-year fallow of Andropogon gayanus-yam rotation, maize-yam rotation) with yam-based systems integrated herbaceous legumes (Aeschynomene histrix/maize intercropping-yam rotation, Mucuna pruriens/maize intercropping-yam rotation). The experiment was conducted during the 2002 and 2004 cropping seasons with 32 farmers, eight in each site. For each of them, a randomized complete block design with four treatments and four replicates was carried out using a partial nested model with five factors: Year, Replicate, Farmer, Site, and Treatment. Analysis of variance (ANOVA) using the general linear model (GLM) procedure was applied to the dry matter (DM) production (tubers, shoots), nutrient contribution to the systems, and soil properties at depths 0-10 and 10-20 cm. DM removed and recycled, total N, P, and K recycled or removed, and soil chemical properties (SOM, N, P, K, and pH water) were significantly improved on yam-based systems with legumes in comparison with traditional systems.

  11. Controle de tiririca (Cyperus rotundus e efeito residual sobre a cultura do feijão do herbicida imazapyr Control of purple nutsedge (Cyperus rotundus and residual effect on dry beans crop of the herbicide imazapyr

    Directory of Open Access Journals (Sweden)

    A.H. Gonçalves

    2001-12-01

    Full Text Available O presente trabalho teve como objetivo avaliar os efeitos de doses de imazapyr no controle de tiririca (Cyperus rotundus em solos de várzea e também seu efeito residual no solo sobre a cultura do feijão (Phaseolus vulgaris, cultivar Carioca, cultivado em diferentes períodos após a aplicação do herbicida imazapyr. Para determinação da eficiência de controle da tiririca foram avaliadas três doses de imazapyr - 375, 750 e 1.500 g ha-1 - aplicadas sobre as plantas de tiririca no estádio de quatro ou cinco folhas verdadeiras. As avaliações de eficiência de controle da planta daninha foram feitas aos 14, 35, 56, 70, 77, 84 e 91 dias após a aplicação dos tratamentos herbicidas (DAA. Na avaliação do efeito residual do imazapyr no solo foram utilizadas as mesmas doses, porém aplicadas em oito épocas: 98, 84, 63, 42, 28, 21, 14 e 7 dias antes da semeadura (DAS do feijão. Constatou-se que 375 g ha-1 de imazapyr resultou em bom controle da tiririca até 35 dias após a aplicação do produto; após esse período observou-se reinfestação da área com esta espécie. Para as doses de 750 e 1.500 g ha-1 observou-se controle eficiente por um período de 70 dias após a aplicação do herbicida. Quanto ao efeito residual do herbicida sobre a cultura de feijão, verificou-se que, quanto maior a dose utilizada e mais próximo da semeadura for aplicado o herbicida, menor a produtividade da cultura. A dose de 375 g ha-1 aplicada aos 98 DAS mostrou-se menos prejudicial à cultura, não havendo perda de rendimento.The objective of this research was to study rates of the herbicide imazapyr for purple nutsedge (Cyperus rotundus control in lowland soils and to determine the carryover period for dry beans (Phaseolus vulgaris, cv Carioca, grown at different timings after the herbicide application. The experiment was carried out at EMBRAPA/CNPMS, in Sete Lagoas, MG, Brazil, and the effect of imazapyr on purple nutsedge was evaluated spraying at three

  12. Greenhouse gas emissions from passive composting of manure and digestate with crop residues and biochar on small-scale livestock farms in Vietnam.

    Science.gov (United States)

    Vu, Quynh Duong; de Neergaard, Andreas; Tran, Toan Duc; Hoang, Huong Thi Thu; Vu, Van Thi Khanh; Jensen, Lars Stoumann

    2015-01-01

    This study investigated the effects of different mixing ratios of crop residues and biochar with liquid digestate from anaerobically treated pig manure on CH₄, CO₂, and N₂O emissions over 84 days in a system of passive aeration composting, resembling typical Vietnamese solid manure storage conditions. Two treatments with solid manure were included for comparison. The results showed that C losses through CH4 and CO₂emissions accounted for 0.06-0.28% and 1.9-26.7%, respectively, of initial total C. CH4 losses accounted for just 0.4-4.0% of total C losses. Total N losses accounted for 27.1-40% of initial total N in which N₂O emissions corresponded to 0.01-0.57% of initial total N, and hence accounted for only 0.1-1.8% of total N losses. It is assumed that the remainder was either the result of denitrification losses to N₂or ammonia volatilization. The composting of biochar (B) or crop residue with digestate (D) showed significantly lower CH4 and N₂O emissions compared with composting manure (M) (p composting of digestate with biochar showed significantly lower CO₂and CH₄emissions and significantly higher N₂O emissions compared to the composting of digestate with rice straw (RS) (p composting of digestate with biochar and rice straw (D + B + RS5:0.3:1) showed significantly reduced N₂O emissions compared with composting digestate with biochar with alone (p Composting sugar cane bagasse (SC) with digestate (D + SC) significantly reduced CH₄and N₂O emissions compared with the composting of rice straw with digestate (D + RS3.5:1 and D + RS5:1) (p < .05).

  13. ROLE OF ALLELOPATHY IN THE STIMULATORY AND INHIBITORY EFFECTS OF HAIRY VETCH COVER CROP RESIDUE IN NO-TILLAGE SUSTAINABLE PRODUCTION SYSTEMS

    Science.gov (United States)

    Cover crops can provide multiple benefits to sustainable cropping systems including building soil organic matter, controlling soil and nutrient losses from fields, moderating radiation and moisture exchange, releasing nutrients for subsequent crops, and suppressing weed and pest populations. Many o...

  14. Alternate switching between MFC and MEC for H2O2 synthesis and residual removal in Bioelectro-Fenton system

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Angelidaki, Irini

    2016-01-01

    and mineralization of 50 mg L-1 methylene blue (MB) was achieved in the MEC mode with apparent first order rate constants of 0.43 and 0.22 h-1, respectively. After switching to the MFC mode, residual H2O2 of 180 mg L-1 was removed at a removal rate of 4.61 mg L-1 h-1 while generating a maximum current density of 0...

  15. Automated multi-plug filtration cleanup for liquid chromatographic-tandem mass spectrometric pesticide multi-residue analysis in representative crop commodities.

    Science.gov (United States)

    Qin, Yuhong; Zhang, Jingru; Zhang, Yuan; Li, Fangbing; Han, Yongtao; Zou, Nan; Xu, Haowei; Qian, Meiyuan; Pan, Canping

    2016-09-01

    An automated multi-plug filtration cleanup (m-PFC) method on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts was developed. The automatic device was aimed to reduce labor-consuming manual operation workload in the cleanup steps. It could control the volume and the speed of pulling and pushing cycles accurately. In this work, m-PFC was based on multi-walled carbon nanotubes (MWCNTs) mixed with other sorbents and anhydrous magnesium sulfate (MgSO4) in a packed tip for analysis of pesticide multi-residues in crop commodities followed by liquid chromatography with tandem mass spectrometric (LC-MS/MS) detection. It was validated by analyzing 25 pesticides in six representative matrices spiked at two concentration levels of 10 and 100μg/kg. Salts, sorbents, m-PFC procedure, automated pulling and pushing volume, automated pulling speed, and pushing speed for each matrix were optimized. After optimization, two general automated m-PFC methods were introduced to relatively simple (apple, citrus fruit, peanut) and relatively complex (spinach, leek, green tea) matrices. Spike recoveries were within 83 and 108% and 1-14% RSD for most analytes in the tested matrices. Matrix-matched calibrations were performed with the coefficients of determination >0.997 between concentration levels of 10 and 1000μg/kg. The developed method was successfully applied to the determination of pesticide residues in market samples.

  16. Synthesis of biochar from residues after biogas production with respect to cadmium and nickel removal from wastewater.

    Science.gov (United States)

    Bogusz, Aleksandra; Nowak, Katarzyna; Stefaniuk, Magdalena; Dobrowolski, Ryszard; Oleszczuk, Patryk

    2017-10-01

    The objective of the study was to investigate the ability of biochars prepared under different temperatures (400 °C and 600 °C) from the residue of biogas production (RBP) for the adsorption of cadmium (Cd(II)) and nickel (Ni(II)) ions from aqueous solution. Furthermore, the RBP biochars adsorption capacity was compared with adsorption capacity of biochar produced from wheat straw at 600 °C (BCS600). The kinetics of the adsorption, the sorption isotherms, the influence of solution pH and the interfering ions (chlorides and nitrates) were investigated. The desorption of Cd(II) and Ni(II) by hydrochloric and nitric acid from biochars was also investigated. The different types of feedstock used for biochar (BC) preparation (RBP and biomass) determined the physico-chemical properties of biochars and hence their adsorption abilities. Generally, biochars produced from RBPs (regardless of temperature) had the greater capacity to adsorb Cd(II) and Ni(II) than the biochar produced from wheat straw. Of the tested models (Freundlich and Langmuir), the Langmuir model was demonstrated to be the best to describe the sorption of Cd(II) and Ni(II). For the kinetic study, the adsorption process proceeded the fastest for BCU400 than BCU600. Furthermore, BCU600 was the most resistant to the influence of interfering ions on adsorption. For the desorption study, BCU400 was characterized by the highest reproducibility of the surface. The comparison of the results obtained in each adsorption step between RBP biochars and BCS600 suggested that the residue from biogas production could be successfully applied for the removal of Cd(II) and Ni(II) ions from aqueous solutions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Nonpoint source pollution by swine farming wastewater in bean crop Poluição difusa da água residuária de suinocultura do feijoeiro

    Directory of Open Access Journals (Sweden)

    André F. Doblinski

    2010-01-01

    Full Text Available In order to verify the environmental impact of the application of swine farming wastewater in bean crop, an experiment was set up in the Experimental Farm of PUCPR - Toledo, PR, Brazil. Runoff and soil samples were collected at the end of the experiment. Four wastewater treatments were utilized during the experiment (50, 100, 150 and 200 m³ ha-1 and the without wastewater as the control. The results demonstrate that (i the amounts of potassium, phosphorus, and nitrogen in runoff are exponential, (ii that phosphorus has a seven-fold polluting potential compared to potassium and three-fold compared to nitrogen, and (iii that the mobility of potassium in the soil profile is the largest, followed by those of nitrogen and phosphorus.Visando verificar o impacto ambiental da aplicação de água residuária de suinocultura na cultura do feijoeiro, instalou-se um experimento na Fazenda Experimental da PUCPR - Toledo, PR, Brasil; para isto, amostras do solo e do escoamento superficial foram coletadas ao final do experimento e se utilizaram quatro taxas de aplicação de água residuária durante o experimento, 50, 100, 150 e 200 m³ ha-1, sem aplicação de água residuária como testemunha. Os resultados demonstraram que: (i as perdas de potássio, fósforo e nitrogênio no escoamento superficial são exponenciais; (ii o fósforo apresenta potencial poluidor sete vezes maior que o potássio e três vezes maior que o nitrogênio; (iii a mobilidade do potássio no perfil do solo é maior, seguida do nitrogênio e do fósforo.

  18. Miscanthus establishment and overwintering in the Midwest USA: a regional modeling study of crop residue management on critical minimum soil temperatures.

    Science.gov (United States)

    Kucharik, Christopher J; Vanloocke, Andy; Lenters, John D; Motew, Melissa M

    2013-01-01

    Miscanthus is an intriguing cellulosic bioenergy feedstock because its aboveground productivity is high for low amounts of agrochemical inputs, but soil temperatures below -3.5 °C could threaten successful cultivation in temperate regions. We used a combination of observed soil temperatures and the Agro-IBIS model to investigate how strategic residue management could reduce the risk of rhizome threatening soil temperatures. This objective was addressed using a historical (1978-2007) reconstruction of extreme minimum 10 cm soil temperatures experienced across the Midwest US and model sensitivity studies that quantified the impact of crop residue on soil temperatures. At observation sites and for simulations that had bare soil, two critical soil temperature thresholds (50% rhizome winterkill at -3.5 °C and -6.0 °C for different Miscanthus genotypes) were reached at rhizome planting depth (10 cm) over large geographic areas. The coldest average annual extreme 10 cm soil temperatures were between -8 °C to -11 °C across North Dakota, South Dakota, and Minnesota. Large portions of the region experienced 10 cm soil temperatures below -3.5 °C in 75% or greater for all years, and portions of North and South Dakota, Minnesota, and Wisconsin experienced soil temperatures below -6.0 °C in 50-60% of all years. For simulated management options that established varied thicknesses (1-5 cm) of miscanthus straw following harvest, extreme minimum soil temperatures increased by 2.5 °C to 6 °C compared to bare soil, with the greatest warming associated with thicker residue layers. While the likelihood of 10 cm soil temperatures reaching -3.5 °C was greatly reduced with 2-5 cm of surface residue, portions of the Dakotas, Nebraska, Minnesota, and Wisconsin still experienced temperatures colder than -3.5 °C in 50-80% of all years. Nonetheless, strategic residue management could help increase the likelihood of overwintering of miscanthus rhizomes in the first few years after

  19. Miscanthus establishment and overwintering in the Midwest USA: a regional modeling study of crop residue management on critical minimum soil temperatures.

    Directory of Open Access Journals (Sweden)

    Christopher J Kucharik

    Full Text Available Miscanthus is an intriguing cellulosic bioenergy feedstock because its aboveground productivity is high for low amounts of agrochemical inputs, but soil temperatures below -3.5 °C could threaten successful cultivation in temperate regions. We used a combination of observed soil temperatures and the Agro-IBIS model to investigate how strategic residue management could reduce the risk of rhizome threatening soil temperatures. This objective was addressed using a historical (1978-2007 reconstruction of extreme minimum 10 cm soil temperatures experienced across the Midwest US and model sensitivity studies that quantified the impact of crop residue on soil temperatures. At observation sites and for simulations that had bare soil, two critical soil temperature thresholds (50% rhizome winterkill at -3.5 °C and -6.0 °C for different Miscanthus genotypes were reached at rhizome planting depth (10 cm over large geographic areas. The coldest average annual extreme 10 cm soil temperatures were between -8 °C to -11 °C across North Dakota, South Dakota, and Minnesota. Large portions of the region experienced 10 cm soil temperatures below -3.5 °C in 75% or greater for all years, and portions of North and South Dakota, Minnesota, and Wisconsin experienced soil temperatures below -6.0 °C in 50-60% of all years. For simulated management options that established varied thicknesses (1-5 cm of miscanthus straw following harvest, extreme minimum soil temperatures increased by 2.5 °C to 6 °C compared to bare soil, with the greatest warming associated with thicker residue layers. While the likelihood of 10 cm soil temperatures reaching -3.5 °C was greatly reduced with 2-5 cm of surface residue, portions of the Dakotas, Nebraska, Minnesota, and Wisconsin still experienced temperatures colder than -3.5 °C in 50-80% of all years. Nonetheless, strategic residue management could help increase the likelihood of overwintering of miscanthus rhizomes in the first few

  20. Carbon sequestration potential of residues of different types of cover crops in olive groves under mediterranean climate

    Energy Technology Data Exchange (ETDEWEB)

    Repullo-Ruiberriz de Torres, M. A.; Carbonell-Bojollo, R.; Alcantara-Brana, C.; Rodriguez-Lizana, A.; Ordonez-Fernandez, R.

    2012-11-01

    The maintenance of plant cover between olive grove lanes until the beginning of spring is a soil management alternative that is gradually being adopted by olive growers. As well as protecting the soil from erosion, plant covers have other advantages such as improving the physicochemical properties of the soil, favouring its biodiversity and contributing towards the capturing of atmospheric carbon and its fixation in the soil. A trial was conducted over three growing seasons in an olive plantation situated in southern Spain. It was designed to evaluate the C fixation potential of the residues of the cover species Brachypodium distachyon, Eruca vesicaria, Sinapis alba and of spontaneous weeds; and also to study the decomposition dynamics of plant residues after mowing cover. After 156 and 171 days of decomposition, the species that released the largest amount of C was Brachypodium with values of 2,157 and 1,666 kg ha{sup -}1 respectively, while the lowest values of 461 and 509 kg ha{sup -}1 were obtained by spontaneous weeds. During the third season (163 days of decomposition) and due to the weather conditions restricting the emergence and growth of cover, spontaneous weeds released the most C with a value of 1,494 kg ha{sup -}1 . With respect to the fixation of C, Sinapis records the best results with an increase in soil organic C (SOC) concentration of 7,690 kg ha{sup -}1 . Considering the three seasons and a depth of 20 cm, the behaviour sequence of the different species in favouring the fixation of soil organic C was Sinapis > Brachypodium > spontaneous weeds > Eruca. (Author) 34 refs.

  1. Utilization of crops residues as compost and biochar for improving soil physical properties and upland rice productivity

    Directory of Open Access Journals (Sweden)

    J. Barus

    2016-07-01

    Full Text Available The abundance of crops waste in the agricultural field can be converted to organic fertilizer throughout the process of composting or pyrolysis to return back into the soil. The study aimed to elucidate the effect of compost and biochar application on the physical properties and productivity of upland rice at Village of Sukaraja Nuban, Batanghari Nuban Sub district, East Lampung Regency in 2015. The amendment treatments were A. control; B. 10 t rice husk biochar/ ha; C. 10 t maize cob biochar/ha; D. 10 t straw compost/ha; E. 10 t stover compost/ha, F. 10 t rice husk biochar/ha + 10 t straw compost/ha; F. 10 t maize cob biochar/ha + 10 t maize stover compost/ha. The treatments were arranged in randomized block design with four replicates. The plot size for each treatment was 10 x 20 m. After incubation for about one month, undisturbed soil samples were taken using copper ring at 10–20 cm depth for laboratory analyzes. Analyses of soil physical properties included bulk density, particle density, total porosity, drainage porosity, and soil water condition. Plant observations conducted at harvest were plant height, number of panicle, number of grain/panicle, and grain weight/plot. Results of the study showed that biochar and compost improved soil physical properties such as bulk density, total porosity, fast drainage pores, water content, and permeability of soil. The combination of rice husk biochar and straw compost gave better effect than single applications on rice production components (numbers of panicle and grains of rice, and gave the highest yield of 4.875 t/ha.

  2. Evaluation of a recent product to remove lipids and other matrix co-extractives in the analysis of pesticide residues and environmental contaminants in foods

    Science.gov (United States)

    This study demonstrates the application of a novel lipid removal product to the residue analysis of 65 pesticides and 52 environmental contaminants in kale, pork, salmon, and avocado by fast, low pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS). Sample preparation involves QuEChE...

  3. Removal and Burial of Weed Seeds by Ants (Hymenoptera: Formicidae) From the Soil Surface of a Cropped Area in Western Australia.

    Science.gov (United States)

    Minkey, D M; Spafford, H

    2016-10-01

    Although granivorous ants are known to collect weed seeds from cropping areas in Australia, the fate of these seeds has not been adequately investigated. Seeds of annual ryegrass (Lolium rigidum Gaud.) and wild radish (Raphanus raphanistrum L.) were placed around the nests of five native ant species (Iridomyrmex greensladei Shattuck, Rhytidoponera metallica Smith, Melophorus turneri Forel, Monomorium rothsteini Forel, and Pheidole hartmeyeri Forel) and tracked continuously over a 24-h period. Removal rates and seed preference of the ant species were evaluated. Ant nests were then excavated to determine the placement of seeds that were taken into each nest. Seed preference, seed removal efficiencies, activity, and seed storage all varied between the ant species. Annual ryegrass seed was collected by three species of ants and was removed from the soil surface more efficiently than wild radish seed. Most ant species stored seed below ground at a depth that is inhibitory to emergence, thereby potentially removing that portion of seed from the seed bank, but some seed was placed at germinable depths. Pheidole hartmeyeri was identified as a likely biological control agent for annual ryegrass seeds and wild radish, while Me. turneri and Mo. rothsteini have potential as biocontrol agents for annual ryegrass, but further research is needed. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Post-processing to remove residual clouds from aerosol optical depth retrieved using the Advanced Along Track Scanning Radiometer

    Science.gov (United States)

    Sogacheva, Larisa; Kolmonen, Pekka; Virtanen, Timo H.; Rodriguez, Edith; Saponaro, Giulia; de Leeuw, Gerrit

    2017-02-01

    Cloud misclassification is a serious problem in the retrieval of aerosol optical depth (AOD), which might considerably bias the AOD results. On the one hand, residual cloud contamination leads to AOD overestimation, whereas the removal of high-AOD pixels (due to their misclassification as clouds) leads to underestimation. To remove cloud-contaminated areas in AOD retrieved from reflectances measured with the (Advanced) Along Track Scanning Radiometers (ATSR-2 and AATSR), using the ATSR dual-view algorithm (ADV) over land or the ATSR single-view algorithm (ASV) over ocean, a cloud post-processing (CPP) scheme has been developed at the Finnish Meteorological Institute (FMI) as described in Kolmonen et al. (2016). The application of this scheme results in the removal of cloud-contaminated areas, providing spatially smoother AOD maps and favourable comparison with AOD obtained from the ground-based reference measurements from the AERONET sun photometer network. However, closer inspection shows that the CPP also removes areas with elevated AOD not due to cloud contamination, as shown in this paper. We present an improved CPP scheme which better discriminates between cloud-free and cloud-contaminated areas. The CPP thresholds have been further evaluated and adjusted according to the findings. The thresholds for the detection of high-AOD regions (> 60 % of the retrieved pixels should be high-AOD (> 0.6) pixels), and cloud contamination criteria for low-AOD regions have been accepted as the default for AOD global post-processing in the improved CPP. Retaining elevated AOD while effectively removing cloud-contaminated pixels affects the resulting global and regional mean AOD values as well as coverage. Effects of the CPP scheme on both spatial and temporal variation for the period 2002-2012 are discussed. With the improved CPP, the AOD coverage increases by 10-15 % with respect to the existing scheme. The validation versus AERONET shows an improvement of the correlation

  5. Anthelminthic efficacy of banana crop residues on gastrointestinal nematodes of sheep: in vitro and in vivo tests.

    Science.gov (United States)

    Nogueira, Flávia Aparecida; Oliveira, Lincoln Nunes; da Silva, Rayana Brito; Nery, Patrícia Silva; Virgínio, Gercino Ferreira; Geraseev, Luciana Castro; Duarte, Eduardo Robson

    2012-07-01

    Resistance to anthelminthics is common due to intensive and incorrect use. In searching for alternatives, extracts of banana plant were evaluated for egg hatching inhibition and fecal egg count reduction of sheep nematodes. Aqueous extracts of the leaf, pseudostem, and heart of the banana plant cv. Prata anã were tested at concentrations of 0.31, 0.62, 1.25, 2.5, 5.0, and 10.0 mg ml(-1) in egg hatching inhibition tests. For in vivo analysis, aqueous extracts were evaluated at dosages calculated according to the 10% lethal dose derived from acute toxicity testing in mice. Efficacy was evaluated at two time periods following oral administration. For the banana extracts at 2.5 mg ml(-1), egg hatching was significantly fewer than the negative control, with an LC(50) and LC(90) of 0.19 and 0.84 mg ml(-1), respectively. In vivo analysis for weeks 1 and 2 following a single treatment with aqueous leaf extract showed 33.1% and 32.5% anthelminthic efficacy, respectively. Further research on higher dosages with more frequent administration is needed to evaluate the potential for utilizing banana plant residues in gastrointestinal nematode control.

  6. Energy conversion of biomass crops and agroindustrial residues by combined biohydrogen/biomethane system and anaerobic digestion.

    Science.gov (United States)

    Corneli, Elisa; Dragoni, Federico; Adessi, Alessandra; De Philippis, Roberto; Bonari, Enrico; Ragaglini, Giorgio

    2016-07-01

    Aim of this study was to evaluate the suitability of ensiled giant reed, ensiled maize, ensiled olive pomace, wheat bran for combined systems (CS: dark fermentation+anaerobic digestion (AD)) producing hydrogen-rich biogas (biohythane), tested in batch under basic operational conditions (mesophilic temperatures, no pH control). Substrates were also analyzed under a single stage AD batch test, in order to investigate the effects of DF on estimated energy recovery (ER) in combined systems. In CS, maize and wheat bran exhibited the highest hydrogen potential (13.8 and 18.9NLkgVS(-1)) and wheat bran the highest methane potential (243.5NLkgVS(-1)). In one-stage AD, giant reed, maize and wheat bran showed the highest methane production (239.5, 267.3 and 260.0NLkgVS(-1)). Butyrate/acetate ratio properly described the dark fermentation, correlating with hydrogen production (r=0.92). Wheat bran proved to be a promising residue for CS in terms of hydrogen/methane potential and ER. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. An analysis of producing ethanol and electric power from woody residues and agricultural crops in East Texas

    Science.gov (United States)

    Ismayilova, Rubaba Mammad

    The increasing U.S. dependence on imported oil; the contribution of fossil fuels to the greenhouse gas emissions and the climate change issue; the current level of energy prices and other environmental concerns have increased world interest in renewable energy sources. Biomass is a large, diverse, readily exploitable resource. This dissertation examines the biomass potential in Eastern Texas by examining a 44 county region. This examination considers the potential establishment of a 100-megawatt (MW) power plant and a 20 million gallon per year (MMGY) ethanol plant using lignocellulosic biomass. The biomass sources considered are switchgrass, sugarcane bagasse, and logging residues. In the case of electricity generation, co-firing scenarios are also investigated. The research analyzes the key indicators involved with economic costs and benefits, environmental and social impacts. The bioenergy production possibilities considered here were biofeedstock supported electric power and cellulosic ethanol production. The results were integrated into a comprehensive set of information that addresses the effects of biomass energy development in the region. The analysis indicates that none of the counties in East Texas have sufficient biomass to individually sustain either a 100% biomass fired power plant or the cellulosic ethanol plant. Such plants would only be feasible at the regional level. Co-firing biomass with coal, however, does provide a most attractive alternative for the study region. The results indicate further that basing the decision solely on economics of feedstock availability and costs would suggest that bioenergy, as a renewable energy, is not a viable energy alternative. Accounting for some environmental and social benefits accruing to the region from bioenergy production together with the feedstock economics, however, suggests that government subsidies, up to the amount of accruing benefits, could make the bioenergies an attractive business opportunity

  8. Coagulation-Sedimentation-Extraction Pretreatment Methods for The Removal of Suspended Solids and Residual Oil From Palm Oil Mill Effluent (Pome

    Directory of Open Access Journals (Sweden)

    Abdul Latif Ahmad, Norliza Ibrahim , Suzylawati Ismail and Subhash Bhatia

    2012-08-01

    Full Text Available Suspended solids and residual oil removal in a liquid are relevant to numerous research areas and industry. The suspended solid cannot be removed completely by plain settling. Large and heavy particles can settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Because of this, it requires efficient physical-chemical pretreatment methods.   Our current research is to study the pretreatment methods in the removal of suspended solids and residual oil content in POME. Preliminary analysis shows that POME contains 40,000 mg/L suspended solid and 4,000 mg/L oil and grease content that relatively very high compared to the maximum allowable limit by the Malaysian Department of Environment which are only 400 mg/L and 50 mg/L respectively. The methods chosen were coagulation-sedimentation method for suspended solids removal and solvent extraction for residual oil removal.  Jar test apparatus was used as the standard procedure for bench-scale testing and alum was used as the coagulant. Parameters studied were alum dosage, mixing time, mixing speed, sedimentation time and pH. For removal of residual oil, six different organic solvents; n-hexane, n-heptane, benzene, petroleum ether, pentane and petroleum benzene were used. For every solvent the effect of solvent ratio, mixing time, mixing speed and pH were analyzed. The results show that the optimum conditions in removal of suspended solid from POME were at pH 4.11, sedimentation time of 100 minutes and 150 rpm mixing speed with 1.5 hr mixing time. N-hexane give the best performance in extracting residual oil from POME with solvent to POME ratio of 6:10. It was estimated about 0.54 grams of oil and grease can be extracted with optimum variables at pH 4, mixing speed of 200 rpm, and 20 minutes mixing time.  Key Words: palm oil mill effluent, coagulation, suspended solid, residual oil, solvent extraction.

  9. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    Science.gov (United States)

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil.

  10. Bioemulsifier production by Microbacterium sp. strains isolated from mangrove and their application to remove cadmiun and zinc from hazardous industrial residue

    Directory of Open Access Journals (Sweden)

    Erick Aniszewski

    2010-03-01

    Full Text Available The contamination of ecosystems with heavy metals is an important issue in current world and remediation technologies should be in according to environmental sustainability concept. Bioemulsifier are promising agents to be used in metal removal and could be effective to many applications in environmental industries. The aims of this work was screening the potential production of bioemulsifier by microorganisms isolated from an oil contaminated mangrove, and evaluate cadmium and zinc removal potential of those strains from a hazardous industrial residue. From that, bioemulsifier-producing bacteria were isolated from urban mangrove sediments. Four isolates were identified as Microbacterium sp by 16S rRNA analysis and were able to reduce up to 53.3% of culture medium surface tension (TS when using glucose as carbon and energy source and 20.2% when sucrose was used. Suspensions containing bioemulsifier produced by Microbacterium sp. strains show to be able to remove cadmium and zinc from contaminated industrial residue, and its ability varied according carbon source. Significant differences in metal removal were observed by all strains depending on the carbon source. When glucose was used, Cd and Zn removal varied from 17 to 41%, and 14 to 68%, respectively. However, when sucrose was used it was observed only 4 to a maximum of 15% of Cd removal, and 4 to 17% of Zn removal. When the same tests were performed after ethanol precipitation, the results were different: the percentages of removal of Zn (7-27% and Cd (14-32% were higher from sucrose cultures. This is the first report of heavy metals removal by bioemulsifier from Microbacterium sp.

  11. Effect of water-washing on the co-removal of chlorine and heavy metals in air pollution control residue from MSW incineration.

    Science.gov (United States)

    Yang, Zhenzhou; Tian, Sicong; Ji, Ru; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2017-06-24

    The present study systemically investigated the effect of a water-washing process on the removal of harmful chlorides, sulfates, and heavy metals in the air pollution control (APC) residue from municipal solid wastes incineration (MSWI), for sake of a better reuse and disposal of this kind of waste. In addition, the kinetic study was conducted to reveal the releasing mechanism of relevant element in the residue. The results show that, over 70wt.% of chlorides and nearly 25wt.% of sulfates in the residue could be removed by water washing. Based on an economical consideration, the optimal operation conditions for water washing of APC residue was at liquid/solid (L/S) ratio of 3mL:1g and extracting time of 5min. As expected, the concentrations of Co, Cr, Fe, Ni, V and Cu in the washing effluent increased with time during the washing process. However, the extracting regime differs among different heavy metals. The concentrations of Ba and Mn increased firstly but declined afterwards, and concentrations of Pb and Zn gradually declined while Cd and As kept constant with the increase of extracting time. It is worth mentioning that the bubbling of CO2 into the washing effluent is promisingly effective for a further removal of Pb, Cu and Zn. Furthermore, kinetic study of the water washing process reveals that the extracting of heavy metals during water washing follows a second-order model. Copyright © 2017. Published by Elsevier Ltd.

  12. Effects of Density, Beech Crop and Winter Feeding on Survival of Juvenile Great Tits; An Analysis of Kluyver's Removal Experiment

    NARCIS (Netherlands)

    Verhulst, Simon

    1992-01-01

    Density dependent processes and the availability of food may play an important role in the determination of population size. To investigate the relationship between density and local survival of juvenile Great Tits Parus m. major Kluyver removed first brood fledglings in two years. An analysis is pr

  13. First Characterization of Biomass Burning Smoke from Cooking Fires, Peat, Crop Residue and Other Fuels By High Resolution PTR-TOF Mass Spectrometry and FTIR

    Science.gov (United States)

    Stockwell, C.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2014-12-01

    Biomass burning (BB) is a major influence on Earth's atmosphere, but for many fire-types the emissions have only been measured for a few species. For all types of BB, progress has been limited by a lack of information on the emissions of semi-volatile organic gases that are precursors for secondary aerosol and ozone. During the Fourth Fire Lab at Missoula Experiment (FLAME-4), the BB emissions from 158 laboratory fires were quantified by ~40 scientists for an assortment of globally relevant fuels including rarely sampled sources such as US and Asian crop residue; Indonesian and extratropical peat; and cooking fires in traditional and advanced stoves. In this work, we present the primary emissions of gas-phase non-methane organic compounds (NMOCs) measured using an advanced Proton-Transfer-Reaction time-of-flight mass spectrometer (PTR-TOF-MS) in tandem with measurements of other major emissions by Fourier transform infrared (FTIR) spectroscopy. We developed a composition and mass dependent sensitivity and best assignments for many observed peaks. The known and tentatively assigned peaks together account for ~80-96% of total observed NMOC mass. Much of the NMOC mass is rarely measured or previously unmeasured high molecular mass compounds including ringed aromatic hydrocarbons, phenolic compounds, and furans, which are all secondary organic aerosol precursors. Large air quality benefits are demonstrated for more advanced cooking technologies. This work produced globally relevant emission ratios and emission factors to better represent biomass burning in current atmospheric models.

  14. Identification and characterization of an anaerobic ethanol-producing cellulolytic bacterial consortium from Great Basin hot springs with agricultural residues and energy crops.

    Science.gov (United States)

    Zhao, Chao; Deng, Yunjin; Wang, Xingna; Li, Qiuzhe; Huang, Yifan; Liu, Bin

    2014-09-01

    In order to obtain the cellulolytic bacterial consortia, sediments from Great Basin hot springs (Nevada, USA) were sampled and enriched with cellulosic biomass as the sole carbon source. The bacterial composition of the resulting anaerobic ethanol-producing celluloytic bacterial consortium, named SV79, was analyzed. With methods of the full-length 16S rRNA librarybased analysis and denaturing gradient gel electrophoresis, 21 bacteria belonging to eight genera were detected from this consortium. Clones with closest relation to the genera Acetivibrio, Clostridium, Cellulosilyticum, Ruminococcus, and Sporomusa were predominant. The cellulase activities and ethanol productions of consortium SV79 using different agricultural residues (sugarcane bagasse and spent mushroom substrate) and energy crops (Spartina anglica, Miscanthus floridulus, and Pennisetum sinese Roxb) were studied. During cultivation, consortium SV79 produced the maximum filter paper activity (FPase, 9.41 U/ml), carboxymethylcellulase activity (CMCase, 6.35 U/ml), and xylanase activity (4.28 U/ml) with sugarcane bagasse, spent mushroom substrate, and S. anglica, respectively. The ethanol production using M. floridulus as substrate was up to 2.63 mM ethanol/g using gas chromatography analysis. It has high potential to be a new candidate for producing ethanol with cellulosic biomass under anoxic conditions in natural environments.

  15. Performance and matrix effect observed in QuEChERS extraction and tandem mass spectrometry analyses of pesticide residues in different target crops.

    Science.gov (United States)

    Lucini, Luigi; Molinari, Gian Pietro

    2011-10-01

    The method performance and matrix effect related to quantitative determination of pesticide residues was assessed after QuEChERS extraction and LC-MS-MS analysis. Dicloran, phosmet and phosmet-oxon, pirimiphos-methyl, and BNOA were analyzed in peach, apple, melon, cereals, tomato, and strawberry. The matrix effects, as well as recovery and process efficiencies, were determined for a fungicide, two insecticides, and a plant growth regulator. Crop samples were spiked either pre- or post-extraction, then the peak area was compared with the peak area in neat solvent. The mean recovery ranged from 73% to 98%, and repeatability (as RSD) was between 3% and 16%, depending on the compound and spiking level. The matrix effect occurred as ionic suppression and was found in the range of 5% to 22% depending on the compound. Recovery efficiencies were good and substantially comparable, being in the range of 93-96%. Although the suppression observed still appears to be acceptable considering the overall process efficiency, it seems evident that the matrix effect is important when a reliable quantitative method must be applied.

  16. Carbon Dioxide, Methane, and Nitrous Oxide Emissions from a Rice-Wheat Rotation as Affected by Crop Residue Incorporation and Temperature

    Institute of Scientific and Technical Information of China (English)

    邹建文; 黄耀; 宗良纲; 郑循华; 王跃思

    2004-01-01

    Field measurements were made from June 2001 to May 2002 to evaluate the effect of crop residue application and temperature on CO2, CH4, and N2O emissions within an entire rice-wheat rotation season.Rapeseed cake and wheat straw were incorporated into the soil at a rate of 2.25 t hm-2 when the rice crop was transplanted in June 2001. Compared with the control, the incorporation of rapeseed cake enhanced the emissions of CO2, CH4, and N2O in the rice-growing season by 12.3%, 252.3%, and 17.5%,respectively, while no further effect was held on the emissions of CO2 and N2O in the following wheatgrowing season. The incorporation of wheat straw enhanced the emissions of CO2 and CH4 by 7.1%and 249.6%, respectively, but reduced the N2O emission by 18.8% in the rice-growing season. Significant reductions of 17.8% for the CO2 and of 12.9% for the N2O emission were observed in the following wheatgrowing season. A positive correlation existed between the emissions of N2O and CO2 (R2 = 0.445, n =73, p < 0.001) from the rice-growing season when N2O was emitted. A trade-off relationship between the emissions of CH4 and N2O was found in the rice-growing season. The CH4 emission was significantly correlated with the CO2 emission for the period from rice transplantation to field drainage, but not for the entire rice-growing season. In addition, air temperature was found to regulate the CO2 emissions from the non-waterlogged period over the entire rice-wheat rotation season and the N2O emissions from the nonwaterlogged period of the rice-growing season, which can be quantitatively described by an exponential function. The temperature coefficient (Q10) was then evaluated to be 2.3±0.2 for the CO2 emission and 3.9±0.4 for the N2O emission, respectively.

  17. Carbon footprints of crops from organic and conventional arable crop rotations – using a life cycle assessment approach

    DEFF Research Database (Denmark)

    Knudsen, Marie Trydeman; Meyer-Aurich, A; Olesen, Jørgen E

    2014-01-01

    organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No...... input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass...... was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments...

  18. Pollutant removal performance of an integrated upflow-constructed wetland filled with haydites made of Al-based drinking water treatment residuals.

    Science.gov (United States)

    Wang, Wendong; Han, Yu; Liu, Hui; Zhang, Ke; Yue, Qiang; Bo, Longli; Wang, Xiaochang

    2017-05-01

    This study examined the pollutants removal performance of an integrated upflow-constructed wetland (IUCW) system in a 1.5 years' continuous operation. The average concentrations of chemical oxygen demand (COD), NH4-N, total nitrogen (TN), and total phosphorus (TP) in the effluent were 21.9, 1.47, 2.63, and 0.18 mg/L, respectively, which corresponded to 90.1%, 23.3%, 86.1%, and 97.2% removals from the raw water, respectively. The residual concentration of COD was 219 mg/L at start-up and decreased notably to 52.8 mg/L after 50 days of operation. NH4-N was difficult to remove because the average concentration of dissolved oxygen in the IUCW system was lower than 0.6 mg/L. In contrast, the residual concentrations of both TN and TP in the effluent were stable, with average removal rates as high as 89% and 99%, respectively, at start-up of the system. Changing the organic loading rates from 45.0 g/(m(2)·day) to 20.0 or 60.0 g/(m(2)·day) both inhibited the removal of TN. Further study showed that the removal of organic matter mainly occurred within 10-20 cm of the wetland cell. Considering its strong organic, nitrogen, and phosphate removal capacity, the IUCW system was determined to be effective in decentralized wastewater treatment.

  19. Short-term response of soil spiders to cover-crop removal in an organic olive orchard in a Mediterranean setting.

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity.

  20. Short-Term Response of Soil Spiders to Cover-Crop Removal in an Organic Olive Orchard in a Mediterranean Setting

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity. PMID:22938154

  1. Influência do tipo e da quantidade de resíduos vegetais associados a herbicidas residuais no desenvolvimento da cultura da soja Influence of the type and amound of crop residues combined with residual herbicides on soybean development

    Directory of Open Access Journals (Sweden)

    Núbia Maria Correia

    2006-01-01

    Full Text Available O objetivo do trabalho foi avaliar, em condições de campo e na região originalmente sob cerrado, os efeitos de resíduos vegetais [sorgo de cobertura (híbrido Cober Exp, milheto forrageiro (var. BN2, capim pé-de-galinha (Eleusine coracana e capim braquiária (Brachiaria brizantha] e duas quantidades de palha (3,0 e 5,5 t ha-1, no primeiro ano do estudo, e 3,5 e 5,8 t ha-1, no segundo, associados a herbicidas residuais (diclosulam a 35 g ha-1 e imazaquin a 140 g ha-1 aplicados em pré-emergência, no desenvolvimento da cultura da soja. Para tal, foi desenvolvido experimento no ano agrícola 2003/2004 e repetido em 2004/2005, na Fazenda Três Marcos, em Uberlândia (MG. No primeiro ano, após a instalação da cultura da soja, plantas de Eleusine coracana tornaram-se as principais infestantes na cobertura de capim pé-de-galinha. Devido à ausência de controle dessa espécie pelos herbicidas testados, a convivência entre ela e a cultura refletiu negativamente nas plantas de soja. O herbicida imazaquin afetou, indiretamente, as plantas de soja, em virtude do seu controle insatisfatório das plantas daninhas. Nas plantas de soja crescidas sobre cobertura de capim braquiária (nos dois anos e de capim pé-de-galinha (no segundo ano observaram-se maior produtividade de grãos, acúmulo de massa e altura de plantas. Os resíduos vegetais de sorgo influenciaram negativamente no desenvolvimento das plantas de soja, nos dois anos. Quanto aos níveis de palha, houve diferença entre eles para milheto forrageiro (no primeiro ano e sorgo (no segundo ano. O menor nível de milheto forrageiro e o maior de sorgo ocasionaram prejuízos às plantas de soja.This work was conducted in the agricultural years 2003/2004 and 2004/2005, at the "Três Marcos" Farm, Uberlândia (MG, Brazil. It was aimed to evaluate the effect of crop residues [coverage sorghum (hybrid Cober Exp, forage millet (var. BN2, finger millet (Eleusine coracana and St. Lucia Grass

  2. Trace gas emissions from combustion of peat, crop residue, biofuels, grasses, and other fuels: configuration and FTIR component of the fourth Fire Lab at Missoula Experiment (FLAME-4

    Directory of Open Access Journals (Sweden)

    C. E. Stockwell

    2014-04-01

    Full Text Available During the fourth Fire Lab at Missoula Experiment (FLAME-4, October–November~2012 a~large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high resolution mass spectrometry, one- and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR spectroscopy. This paper summarizes the overall experimental design for FLAME-4 including the fuel properties, the nature of the burn simulations, the instrumentation employed, and then focuses on the OP-FTIR results. The OP-FTIR was used to measure the initial emissions of 20 trace gases: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. These species include most of the major trace gases emitted by biomass burning and for several of these compounds it is the first time their emissions are reported for important fuel types. The main fuel types included: African grasses, Asian rice straw, cooking fires (open (3-stone, rocket, and gasifier stoves, Indonesian and extratropical peat, temperate and boreal coniferous canopy fuels, US crop residue, shredded tires, and trash. Comparisons of the OP-FTIR emission factors (EF and emission ratios (ER to field measurements of biomass burning verify that the large body of FLAME-4 results can be used to enhance the understanding of global biomass burning and its representation in atmospheric chemistry models.

  3. Characterization of biomass burning smoke from cooking fires, peat, crop residue and other fuels with high resolution proton-transfer-reaction time-of-flight mass spectrometry

    Science.gov (United States)

    Stockwell, C. E.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2014-08-01

    We deployed a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass burning emissions from peat, crop-residue, cooking fires, and many other fire types during the fourth Fire Lab at Missoula Experiment (FLAME-4) laboratory campaign. A combination of gas standards calibrations and composition sensitive, mass dependent calibration curves were applied to quantify gas-phase non-methane organic compounds (NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign best identities to most major "exact masses" including many high molecular mass species. Using these methods approximately 80-96% of the total NMOC mass detected by PTR-TOF-MS and FTIR was positively or tentatively identified for major fuel types. We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of which are suspected secondary organic aerosol precursors. A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief study of various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open 3-stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types that together accounted for 0.1-8.7% of the fuel nitrogen and some may play a role in new particle formation.

  4. Characterization of biomass burning emissions from cooking fires, peat, crop residue, and other fuels with high-resolution proton-transfer-reaction time-of-flight mass spectrometry

    Science.gov (United States)

    Stockwell, C. E.; Veres, P. R.; Williams, J.; Yokelson, R. J.

    2015-01-01

    We deployed a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to measure biomass-burning emissions from peat, crop residue, cooking fires, and many other fire types during the fourth Fire Lab at Missoula Experiment (FLAME-4) laboratory campaign. A combination of gas standard calibrations and composition sensitive, mass-dependent calibration curves was applied to quantify gas-phase non-methane organic compounds (NMOCs) observed in the complex mixture of fire emissions. We used several approaches to assign the best identities to most major "exact masses", including many high molecular mass species. Using these methods, approximately 80-96% of the total NMOC mass detected by the PTR-TOF-MS and Fourier transform infrared (FTIR) spectroscopy was positively or tentatively identified for major fuel types. We report data for many rarely measured or previously unmeasured emissions in several compound classes including aromatic hydrocarbons, phenolic compounds, and furans; many of these are suspected secondary organic aerosol precursors. A large set of new emission factors (EFs) for a range of globally significant biomass fuels is presented. Measurements show that oxygenated NMOCs accounted for the largest fraction of emissions of all compound classes. In a brief study of various traditional and advanced cooking methods, the EFs for these emissions groups were greatest for open three-stone cooking in comparison to their more advanced counterparts. Several little-studied nitrogen-containing organic compounds were detected from many fuel types, that together accounted for 0.1-8.7% of the fuel nitrogen, and some may play a role in new particle formation.

  5. The Predisposition of Iraqi Rice Husk to Remove Heavy Metals from Aqueous Solutions and Capitalized from Waste Residue

    OpenAIRE

    Mohammed Nsaif; Firas Saeed

    2013-01-01

    This study is deal with study the potential of Iraqi Rice Husk (IRH) on the removal of three heavy metals pollutant which were (Mg, Mn and Mo) ions from industrial wastewater using different design parameters by adsorption process. Results show that the removal efficiency were (93.95, 97.18 and 95.26) % for heavy metal (Mg, Mn and Mo) respectively from aquatic solution decreased with increasing of initial concentration and flow rate while the removal efficiency increased with increasing absor...

  6. Evaluation of ozonation technique for pesticide residue removal and its effect on ascorbic acid, cyanidin-3-glucoside, and polyphenols in apple (Malus domesticus) fruits.

    Science.gov (United States)

    Swami, Saurabh; Muzammil, Raunaq; Saha, Supradip; Shabeer, Ahammed; Oulkar, Dasharath; Banerjee, Kaushik; Singh, Shashi Bala

    2016-05-01

    Ozonated water dip technique was evaluated for the detoxification of six pesticides, i.e., chlorpyrifos, cypermethrin, azoxystrobin, hexaconazole, methyl parathion, and chlorothalonil from apple fruits. Results revealed that ozonation was better than washing alone. Ozonation for 15 min decreased residues of the test pesticides in the range of from 26.91 to 73.58%, while ozonation for 30 min could remove the pesticide residues by 39.39-95.14 % compared to 19.05-72.80 % by washing. Cypermethrin was the least removed pesticide by washing as well as by ozonation. Chlorothalonil, chlorpyrifos, and azoxystrobin were removed up to 71.45-95.14 % in a 30-min ozonation period. In case of methyl parathion removal, no extra advantage could be obtained by ozonation. The HPLC analysis indicated that ozonation also affected adversely the ascorbic acid and cyanidin-3-glucoside content of apples. However, 11 polyphenols studied showed a mixed trend. Gallic acid, 3,4-dihydroxybenzoic acid, catechin, epicatechin, p-coumaric acid, quercetin-3-O-glucoside, quercetin, and kaempferol were found to decrease while syringic acid, rutin, and resveratrol were found to increase in 30-min ozonation.

  7. 农作物与其剩余物制备纳米纤维素研究进展%Research Progress of Nanocrystalline Cellulose Prepared from Crops and Agricultural Residues

    Institute of Scientific and Technical Information of China (English)

    宋孝周; 吴清林; 傅峰; 郭康权

    2011-01-01

    简要介绍了农业纤维主要组成成分,从原料种类、制备方法、纳米纤维素的性质及应用4个方面综述了利用农作物及其剩余物制备纳米纤维素的国内外研究进展.深入分析了利用农作物及其剩余物制备纳米纤维素在尺寸表征、表面改性、制备工艺及应用方面存在的主要问题及解决思路,为农作物及其剩余物的高值化应用提供参考.%The preparation of nanocrystalline cellulose using crops and agricultural residues has attracted wide attention recently. The primary composition of agricultural fibers was introduced. Research progress of nanocrystalline cellulose prepared from crops and agricultural residues was reviewed in terms of raw material kinds, preparation method, properties and application of nanocrystalline cellulose. The main problems in terms of dimensional measurement, surface modification, preparation technology and application were analyzed. The corresponding solution ways were put forward. The preparation of nanocrystalline cellulose is a high value-added application for crops and agricultural residues.

  8. Occurrence of Faustinus sp. (Coleoptera: Curculionidae in Southeastern Brazil tomato crops

    Directory of Open Access Journals (Sweden)

    Gustavo Dias de Almeida

    2009-12-01

    Full Text Available Occurrence of Faustinus sp. (Coleoptera: Curculionidae in tomato (Solanum lycopersicum L. plantations in the State of Espirito Santo, Brazil, was confirmed through field observations carried out between April 2006 and March 2008. Larvae of Faustinus sp. bore the stems of tomato plants, whereas adults feed on the leaves. Bored stems are then easily broken by the wind, by manual handling or by plant weight itself. Crop rotation and removal of crop residues may help reduce pest population levels.

  9. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato - A case study

    Science.gov (United States)

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  10. Nitrate leaching and residual effect in dairy crop rotations with grass-clover leys as influenced by sward age, grazing, cutting and fertilizer regimes

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Rasmussen, Jim;

    2015-01-01

    Intensive dairy farming, with grass-arable crop rotations is challenged by low N use efficiency that may have adverse environmental consequences. We investigated nitrate leaching and N fertility effects of grass–clover leys for five years in two organic crop rotations with different grassland...... proportions (33 and 67%) and five grassland managements in terms of cutting, grazing, fertilization and combinations thereof. In grass–clover, the combination of fertilization and grazing caused excessive leaching (average 60 kg N ha−1) but leaving out either fertilization or full-time grazing substantially...... and fertilization and lowest without fertilization or cutting-only management and was not influenced by grassland age. The arable part of the mixed crop rotation was nitrate leaky where crop coverage in autumn was insufficient. Nitrate leaching following the crops may roughly be divided into four groups: (1) low...

  11. Glyphosate Mineralization: Effect of Temperature and Soybean and Corn Crop Residues Mineralización de Glifosato: Efecto de la Temperatura y los Residuos Vegetales de Soya y Maíz

    Directory of Open Access Journals (Sweden)

    Ariel Rampoldi

    2008-03-01

    Full Text Available Mineralization is the main mechanism of dissipation of glyphosate herbicide (N-[phosphonomethyl] glycine in soil. However, there is scarce information about the mineralization process in strata formed by stubbles in no-tillage systems. The kinetics and rate of mineralization of herbicide in stubbles of soybean (Glycine max L. Merr. and corn (Zea mays L. were investigated. To evaluate the effect of age of crop residues, samples of soybean stubbles were collected immediately after harvest (Soja 1 and four months after harvest (Soja 2. Corn crop residues were collected three months after harvest. Glyphosate evolution and total microbial activity (TMA were monitored by release of 14C-CO2 and C-CO2 under laboratory conditions with two temperatures, 15 and 28 ºC. Crop residues size was evaluated using grinding (1 mm and cut (1 to 2 cm stubbles. Results showed that glyphosate mineralization was affected by the incubation temperature and the origin and age of crop residues. Size of crop residues did not modify glyphosate mineralization. Average glyphosate mineralization after 56 days of incubation at 15 and 28 ºC was of 3.9 and 9.9%, respectively, of the 14C-glyphosate initially applied. In maize crop residues the percentages were 2.0 and 3.0%, respectively, at 15 and 28 ºC. A similar evolution was detected for TMA. The co-metabolic nature of glyphosate mineralization was corroborated. An inverse relation between C/N ratio and glyphosate mineralization was detected. Higher glyphosate mineralization was detected in fresh soybean stubbles, suggesting that applications on aged crop residues could increase the persistence of glyphosate in no-tillage systemsLa mineralización es el principal mecanismo de disipación del herbicida glifosato (N-[fosfonometil] glicina en el suelo. Existe escasa información sobre el proceso de mineralización de glifosato en el estrato formado por rastrojos en suelos cultivados en sistema de siembra directa. Las muestras de

  12. The Predisposition of Iraqi Rice Husk to Remove Heavy Metals from Aqueous Solutions and Capitalized from Waste Residue

    Directory of Open Access Journals (Sweden)

    Mohammed Nsaif

    2013-12-01

    Full Text Available This study is deal with study the potential of Iraqi Rice Husk (IRH on the removal of three heavy metals pollutant which were (Mg, Mn and Mo ions from industrial wastewater using different design parameters by adsorption process. Results show that the removal efficiency were (93.95, 97.18 and 95.26 % for heavy metal (Mg, Mn and Mo respectively from aquatic solution decreased with increasing of initial concentration and flow rate while the removal efficiency increased with increasing absorbance material bed height, pH and feeding temperature. Statistical model is achieved to find an expression relates the overall operating parameters with the removal efficiency for each metal ions used in this investigation in a general equation (each one alone. The samples of (IRH remaining after using it in the removal of (Mg, Mn and Mo heavy metal ions above from Simulated Synthetic Aqueous Solutions (SSAS to investigate the capitalized of it in different methods. Different benefits possess which are: remove the three toxic heavy metals ions contaminated the water, get rid of agricultural waste (IRH, in the same time, produce light and more benefit hydrocarbons from n-heptane isomerization using a type Y-zeolite catalyst synthesis from remaining (IRH and prepare a cheap and active rodenticide.

  13. A Novel Magnetic Graphene Oxide Composite Absorbent for Removing Trace Residues of Polybrominated Diphenyl Ethers in Water

    Directory of Open Access Journals (Sweden)

    Ning Gan

    2014-08-01

    Full Text Available The purpose of the study was to develop a facile method for the fabrication of a stable and reusable magnetic graphene composite absorbent to remove trace levels of polybrominated diphenyl ethers in water treatment. The poly cationic Fe3O4@PDDA (poly(diallyldimethyl ammonium chloride (PDDA core-shell structured nanoparticles were first synthesized, and then, DNA was laid on the surface of graphene oxide (GOx to prepare the polyanionic GOx@DNA composite. The above materials were then mixed together and adhered together through sol-gel technology. Thus, the Fe3O4@PDDA/GOx@DNA composite absorbent was prepared. Its performance was tested by disperse solid phase extraction and gas chromatography/mass spectrometric (GC/MS for removing six kinds of indicative polybrominated diphenyl ethers (BDEs in water samples. The removal percentages of several real samples for six kinds of BDEs (BDE17, BDE28, BDE 71, BDE 47, BDE 66, BDE 100 at the ng/mL order of magnitude were in the range of 88.2%–99.1%. The removal percentage still reached 80.0% when the adsorbent was reused at least 20 times. The results suggested that the magnetic absorbent can obviously remove trace levels of BDEs from large volumes of aqueous solutions in environmental pollution cleanup with high removal efficiency.

  14. Effects of a complete removal of harvest residues on the soil fauna; Effekter av GROT-uttag paa biologisk maangfald hos markfaunan

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tryggve; Ahlstroem, Kerstin; Lindberg, Niklas [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    2005-02-01

    The aim was to assess the effects of a complete removal of harvest residues (slash) from forest clear-cuts in relation to a situation with 1,2 and 4 times normal amount of harvest residues on the diversity of soil fauna. The study was made at two sites, Asa in Smaaland and Turbo in Dalarna. The comparison also included uncut, mature forests surrounding the clear-cuts. Ideally, the study should have continued for several years, but because of limited economy, the study focused on the period 1.5 year after the clear-cut. The soil fauna groups reported here are Enchytraeidae, Tardigrada, Diptera and Oribatida. The results show that clear-cutting leads to a marked decline in the density and species number of oribatid mites and an increase in the density (but not species) of Enchytraeidae. Slash removal could not be shown to affect the species number of oribatids. Certain species clearly decreased in number after slash removal, but the species were normally present, although in low numbers, 1.5 year after the clear-cut. Some Diptera species (larvae) were solely observed below the heaps of slash, but the results are too circumstantial for a certain conclusion. The short period between the treatment start and the sampling limits the generality of the findings. The generation times of most oribatid mites are one year or more. There are studies indicating that some species have generation times up to 2-3 years. If the sensitive life stages are the juveniles, presence of long-lived adults may hide detrimental effects. This means that the study has covered too short a time to conclude whether removal of slash will affect oribatid diversity. Consequently, we cannot exclude the possibility that removal of harvest residues can result in a threat to the diversity of oribatid mites. To be able to answer the question in a satisfactorily manner, a follow-up study is needed during forthcoming years. In conclusion, removal of slash had small effects on enchytraeid species and reduced

  15. Residual effect of soil tillage on water erosion from a Typic Paleudalf under long-term no-tillage and cropping systems

    Directory of Open Access Journals (Sweden)

    Mastrângello Enívar Lanzanova

    2013-12-01

    Full Text Available Soil erosion is one of the chief causes of agricultural land degradation. Practices of conservation agriculture, such as no-tillage and cover crops, are the key strategies of soil erosion control. In a long-term experiment on a Typic Paleudalf, we evaluated the temporal changes of soil loss and water runoff rates promoted by the transition from conventional to no-tillage systems in the treatments: bare soil (BS; grassland (GL; winter fallow (WF; intercrop maize and velvet bean (M+VB; intercrop maize and jack bean (M+JB; forage radish as winter cover crop (FR; and winter cover crop consortium ryegrass - common vetch (RG+CV. Intensive soil tillage induced higher soil losses and water runoff rates; these effects persisted for up to three years after the adoption of no-tillage. The planting of cover crops resulted in a faster decrease of soil and water loss rates in the first years after conversion from conventional to no-tillage than to winter fallow. The association of no-tillage with cover crops promoted progressive soil stabilization; after three years, soil losses were similar and water runoff was lower than from grassland soil. In the treatments of cropping systems with cover crops, soil losses were reduced by 99.7 and 66.7 %, compared to bare soil and winter fallow, while the water losses were reduced by 96.8 and 71.8 % in relation to the same treatments, respectively.

  16. Removal of residual colonic ciprofloxacin in the rat by activated charcoal entrapped within zinc-pectinate beads.

    Science.gov (United States)

    Khoder, Mouhamad; Tsapis, Nicolas; Domergue-Dupont, Valérie; Gueutin, Claire; Fattal, Elias

    2010-10-09

    Residual antibiotics reaching the colon have many deleterious effects on the colonic microbiota including the selection of new antibiotic resistances. In order to avoid the selection of ciprofloxacin resistance, intestine or colon-targeted zinc-pectinate beads containing activated charcoal (AC) were designed for the inactivation of residual ciprofloxacin in the gastrointestinal tract of rats. Bead stability after oral administration was adjusted by tuning the concentration of zinc in the gelling bath and the number of washings. Intestine and colon-targeted beads were administered along with 50mg/kg of ciprofloxacin and ciprofloxacin was dosed in the plasma and the feces using HPLC. Ciprofloxacin pharmacokinetics was not affected by the oral co-administration of beads. The co-administration of intestine-targeted beads led to a significant decrease of the residual fecal free ciprofloxacin with a pronounced dose effect. Our study suggests the rat model is not appropriate for the investigation of bacteria responsive colon-targeted beads probably due to the important anatomical and physiological differences between human and rat gastrointestinal tracts. The ability of AC loaded zinc-pectinate beads to selectively decrease the intestinal residual fraction of ciprofloxacin could provide a better protection of the intestinal microbiota and may prevent the emergence of ciprofloxacin resistance in the gastrointestinal tract.

  17. Efeito residual no solo dos herbicidas imazamox e imazethapyr para as culturas de milho e sorgo Soil residual effect of the herbicides imazamox and imazethapyr to corn and sorghum crops

    Directory of Open Access Journals (Sweden)

    Antonio A. da Silva

    1999-12-01

    Full Text Available Durante o ano agrícola 1994/95, foi conduzido ensaio de campo, em Capinópolis, MG, visando avaliar o efeito residua l no solo dos herbicidas imazamox (50 e 100 g/ha e imazethapyr (100 e 200 g/ha, aplicados à cultura da soja, sobre as culturas de milho e sorgo, cultiva das em sistema de sucessão à soja. Foram realizados, em casa de vegetação, bioensaios utilizando o sorgo como planta - teste, em amostras de solo coletadas nas parcelas onde foram aplicados os herbicidas no campo. As amostras de solo foram coletadas aos 30, 60, 90 e 120 dias após a aplicação (DAA dos herbicidas. Um dia após a colheita da soja, fez-se também a semeadura, no campo, do milho e do sorgo nas parcelas anteriormente ocupadas com a soja, onde haviam sido feitas as aplicações dos herbicidas. Os resultados obtidos indicam que o imazamox apresentou menor efeito residual, não influenciando no desenvolvimento da planta-teste quando esta foi semeada aos 120 DAA, até mesmo no dobro da dose recomendada. Todavia, o imazethapyr a 200 g/ha (dobro da dose recomendada apresentou inibição no desenvolvimento das plantas de sorgo quando estas foram semeadas 120 DAA. Em condições de campo, plantas de sorgo semeadas após a colheita da soja em áreas que receberam o dobro da dose recomendada de imazethapyr evidenciaram menor altura de plantas e menor comprimento de panícula do sorgo, não influenciando, entretanto, a produtividade de grãos.During the 1994/95 growing season, a field assay was conducted in Capinópolis, MG, to evaluate the carryover effect of the herbicides imazamox (50 and 100 g/ha, and imazethapyr (100 and 200 g/ha, applied in soybean, to corn and sorghum crops succeeding soybean. Bioassays using sorghum as test-plant were conducted in greenhouse conditions using soil samples collected from plots sprayed with the herbicides in field. Soil samples were collected at 30, 60, 90 and 120 days after application (DAA of herbicides. One day after soybean

  18. Controle de plantas daninhas em milho em função de quantidades de palha de nabo forrageiro Weed control in corn as a function of amount of turnip crop residue

    Directory of Open Access Journals (Sweden)

    M.A. Rizzardi

    2006-06-01

    Full Text Available Objetivou-se com este experimento avaliar a influência da quantidade de palha de nabo forrageiro (Raphanus sativus var. oleiferus no controle de plantas daninhas em milho. O delineamento experimental foi o de parcelas subdivididas, em blocos casualizados, com quatro repetições. Os tratamentos constaram das quantidades de 0, 6 e 9 t ha-1 de palha de nabo forrageiro, além do pousio, dispostas na parcela principal e, ainda, de seis momentos de controle de plantas daninhas (milho com 1, 2, 4, 5, 6 e 7 folhas, mais duas testemunhas (sem a presença de plantas daninhas e sem o controle destas, dispostos nas subparcelas. Houve interação de quantidades de palha e momentos de controle em relação ao grau de controle de plantas daninhas; o melhor momento ocorreu entre os estádios de duas a quatro folhas do milho. Na ausência de controle químico, o rendimento de grãos de milho foi superior no tratamento com 9 t ha-1 de palha de nabo forrageiro. O controle químico não proporcionou aumento significativo no rendimento de grãos do milho quando a quantidade de palha de nabo forrageiro foi de 9 t ha-1.The objective of this study was to evaluate the effect of the amount of turnip (Raphanus sativus var. oleiferus crop residue on weed control in corn. The experimental design was a split-plot, in randomized blocks, with four replications. The treatments tested were 0, 6, and 9 t ha-1 of turnip crop residues, fallow period (the amount of residues was equivalent to the amount of natural vegetation residues, arranged as main plots, and six weed control periods (corn plants with 1, 2, 4, 5, 6, and 7 developed leaves, besides two controls (one without weeds and another without weed control, arranged as subplots. Interactions occurred between residue amounts and control periods in relation to the degree of weed control. The best control period was achieved when the corn plants presented from 2 to 4 developed leaves. Corn grain yield was higher in the control

  19. 污染土壤残油的臭氧氧化研究%Removal of residual oil in contaminated soil by ozonation

    Institute of Scientific and Technical Information of China (English)

    王坚

    2013-01-01

    Residual oil after bioremediation in crude oil contaminated soil could be hardly biodegraded.In this study, column experiments were carried out to evaluate the effects of ozonation of residual oil. Maximum of removal efficiency(0.3mg oil/mg O3)was reached when ozone dosage was about 20 mg/g soil.Under this condition,population of petroleum degrading bacteria was reduced only by 1 order of magnitude.Among the four fractions of oil,aromatics showed highest removal,followed by saturates,and resins and asphaltenesincreased after ozonation.Ozonation was able to remove residual oil with all range of molecular weight, resulting in a slight decrease of average molecular weight of residual oil.GC-MS results indicated that ozone removal rate of different types of contaminants showed following sequence: polycyclic aromatic hydrocarbons(PAHs)>steranes> hopanes>alkyl cyclohexanes>n-alkanes.Ozonation did not change biomarker parameters.Increase of C15~C22n-alkanes,C17~C20 alkyl cyclohexanes and C8~C22carboxylic acids and production of C11~C25aldehydes were observed after ozonation. Removal rate for biodegradation of ozonated residual oil was twice of the control,indicating that bioavailability of residual oil was improved by ozonation.%本研究探讨了臭氧氧化对石油污染土壤生物修复后难降解的残油的去除效应。臭氧投加剂量约20 mg O3/g 土时,臭氧氧化效率最高,达0.3 mg总油/mgO3,且土壤石油烃降解菌数量仅下降一个数量级。臭氧作用下残油四组分中芳香烃降解率最高,其次为饱和烃,胶质和沥青质含量升高。臭氧对残油各分子量组分均有降解作用,氧化后残油分子量略有下降。GC-MS结果表明臭氧对各类物质氧化的容易顺序为多环芳烃>甾烷>藿烷>烷基环己烷>正烷烃;臭氧未改变生物标志物参数;氧化后C8~C22脂肪酸、C15~C22正烷烃和C17~C20烷基环己烷含量增加,并出现了C11~C25脂肪醛,臭氧氧化后残

  20. Evaluation of residue management practices effects on corn productivity, soil quality, and greenhouse gas emissions

    Science.gov (United States)

    Guzman, Jose German

    The removal of crop residues left after harvest is being considered as a potential feedstock source for bioethanol production which can contribute to the reduction of fossil fuel use and net greenhouse gas (GHG). The objectives of this study were to: (i) examine how tillage, N fertilization rates, residue removal, and their interactions affect crop productivity, (ii) SOC and soil physical properties, and (iii) GHG emissions, and (iv) calculated a soil C budget to determine how much crop residue can be sustainably be removed in Central and Southwest Iowa. After three years of residue removal under different management practices, the findings of this study suggest that a portion of the corn residue that is left on the soil surface after harvest can be removed, with no negative impacts in the short term continuous corn yield in sites at Central and Southwest Iowa. However, significant decreases in SOC sequestration rates, microbial biomass-C, bulk density, soil penetration resistance, wet aggregate stability, and infiltration rates were observed, but varied with soil type and management practices. Additionally, soil surface CO2 and N2O emissions were responsive to management practices; primarily by altering soil temperature, soil water content, soil mineral N, and crop growth. Results from soil C budget show that in 2010 when corn growth was not water stressed (lack of moisture), approximately 35 and 30% of the residue could be sustainably removed in the Central and Southwest sites, respectively. In 2011, drier soil conditions resulted in approximately 2 and 49% of the residue could be sustainably removed in the Central and Southwest sites, respectively.

  1. Removal of Methylene Blue from Aqueous Solution Using Agricultural Residue Walnut Shell: Equilibrium, Kinetic, and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Ranxiao Tang

    2017-01-01

    Full Text Available Walnut shell (WS, as an economic and environmental-friendly adsorbent, was utilized to remove methylene blue (MB from aqueous solutions. The effects of WS particle size, solution pH, adsorbent dosage and contact time, and concentration of NaCl on MB removal were systematically investigated. Under the optimized conditions (i.e., contact time ~ 2 h, pH ~ 6, particle size ~ 80 mesh, dye concentration 20 mg/L, and 1.25 g/L adsorbent, the removal percentages can achieve ~97.1%, indicating WS was a promising absorbent to remove MB. Other supplementary experiments, such as Fourier transform infrared spectroscopy (FTIR, dynamic light scattering (DLS, and Brunauer-Emmett-Teller (BET method, were also employed to understand the adsorption mechanisms. FTIR confirmed that the successful adsorption of MB on WS particles was through functional groups of WS. Using DLS method, the interactions between WS particles and dyes under various pH were investigated, which can be ascribed to the electrostatic forces. Kinetic data can be well fitted by the pseudo-second-order model, indicating a chemical adsorption. The adsorption isotherms were well described by both Langmuir and Freundlich models. Dubinin-Radushkevich model also showed that the adsorption process was a chemical adsorption. Thermodynamic data indicated that the adsorption was spontaneous, exothermic, and favorable at room temperature.

  2. Evaluating the Efficiency of Air Shower in Removing Lead from Army Combat Uniform Swatches Loaded with Gunshot Residue

    Science.gov (United States)

    2016-03-25

    wipes with citric acid and isostearamidopropyl morpholine lactate (ISML) have shown a 99.9% Pb removal efficiency while washing hands with soap and...24 Cleaning Cycle Duration... acid ANOVA Analysis of Variance AS Air shower Ba Barium BEI Biological Exposure Index BLL Blood lead level CP Coproporphyrin DoD

  3. Impact of corn stover removal on soil microbial communities in no-till and conventional till continuous corn

    Science.gov (United States)

    Corn (Zea mays L.) residue, or stover, can be used as a dry forage replacement in beef cattle diets and is being considered as a feedstock for cellulosic biofuel production. The soil quality and crop productivity ramifications of removing stover, however, likely will depend on stover removal rate an...

  4. An Innovative Passive Residual Heat Removal System of an Open-Pool Type Research Reactor with Pump Flywheel and Gravity Core Cooling Tank

    Directory of Open Access Journals (Sweden)

    Kwon-Yeong Lee

    2015-01-01

    Full Text Available In an open-pool type research reactor, the primary cooling system can be designed to have a downward flow inside the core during normal operation because of the plate type fuel geometry. There is a flow inversion inside the core from the downward flow by the inertia force of the primary coolant to the upward flow by the natural circulation when the pump is turned off. To delay the flow inversion time, an innovative passive system with pump flywheel and GCCT is developed to remove the residual heat. Before the primary cooling pump starts up, the water level of the GCCT is the same as that of the reactor pool. During the primary cooling pump operation, the water in the GCCT is moved into the reactor pool because of the pump suction head. After the pump stops, the potential head generates a downward flow inside the core by moving the water from the reactor pool to the GCCT and removes the residual heat. When the water levels of the two pools are the same again, the core flow has an inversion of the flow direction, and natural circulation is developed through the flap valves.

  5. Use of residues and by-products of the olive-oil production chain for the removal of pollutants from environmental media: A review of batch biosorption approaches.

    Science.gov (United States)

    Anastopoulos, Ioannis; Massas, Ioannis; Ehaliotis, Constantinos

    2015-01-01

    Residues and by-products of the olive-oil production chain have been widely studied as biosorbents for the removal of various pollutants from environmental media due to their significant adsorption properties, low cost, production at local level and renewability. In this review, adsorbents developed from olive-tree cultivation residues and olive-oil extraction by-products and wastes are examined, and their sorption characteristics are described and discussed. Recent information obtained using batch sorption studies is summarized and the adsorption mechanisms involved, regarding various aquatic and soil pollutants (metal ions, dyes, radionuclides, phenolic compounds, pesticides) are presented and discussed. It is evident that several biosorbents show the potential to effectively remove a wide variety of pollutants from aqueous solutions, especially Pb and Cd. However, there is need to (a) develop standardized batch study protocols, and potentially reference materials, for effective cross-evaluation of biosorbents of similar nature and for improved understanding of mechanisms involved and (b) investigate scaling-up and regeneration issues that hold back industry-level application of preselected adsorbents.

  6. Sources of Error in Remote Sensing-Based Bottom-Up Emission Estimates of Carbon and Air Quality Emissions from Crop Residue Burning in the Contiguous United States and the Russian Federation

    Science.gov (United States)

    McCarty, J. L.; Romanenkov, V.

    2010-12-01

    Since its publication in 1980, the Seiler and Crutzen bottom-up method of estimating biomass burning emissions has become an accepted and standard approach cited in nearly 500 peer-reviewed scientific publications. As the science of biomass burning emissions advances, the need to quantify error in variable inputs has also grown. This research focuses on bottom-up emission estimates of black carbon (BC), CO2, CO, CH4, PM10, PM2.5, NO2, and SO2 from crop residue burning in the contiguous U.S. (CONUS) and the Russian Federation. Crop residue burning emissions for the CONUS were estimated for a five-year period, 2003 through 2007, using multispectral remote sensing-derived products, specifically multi-year crop type maps, an 8-day difference Normalized Burn Ratio product, and calibrated area estimates of cropland burning from 1 km MODIS Active Fire Points. An emission factor database was assembled from eleven published sources while fuel loads and combustion completeness were derived from expert knowledge and governmental reports. With the aim of transferring technique and knowledge to in-country collaborators, crop residue burning emissions in Russia were calculated from burned area estimates derived from the 1 km MODIS Active Fire Points. A second analysis of burned area estimates from both a regionally tuned 8-day difference Normalized Burn Ratio product and the standard MODIS Burned Area product focused on the European region of Russia. For these analyses, BC emission factors were estimated by multiplying published BC to PM2.5 ratios to PM2.5 emission factors for similar crops in the CONUS. Errors and uncertainties were quantified for emission factors, fuel loads, combustion completeness, and accuracies of remote sensing products for both burned area and land cover type for the analyses in the CONUS and Russia. The uncertainty for the non-remote sensing variables was difficult to quantify given the lack of observations available. The results from this uncertainty

  7. Investigation of Pharmaceutical Residues in Hospital Effluents, in Ground- and Drinking Water from Bundeswehr Facilities, and their Removal During Drinking Water Purification (Arzneimittelrueckstaende in Trinkwasser(versorgungsanlagen) und Krankenhausabwaessern der Bundeswehr: Methodenentwicklung - Verkommen - Wasseraufbereitung)

    Science.gov (United States)

    1999-11-01

    Fluorchinolo- ne ( Ciprofloxacin , Norfloxacin , Enrofloxacin, Ofloxacin), Chloramphenicol, Lincomycin, Clindamycin und Trimethoprim mit Konzentrationen bis in den...water from Bundeswehr facilities, and their removal during drinking water purification) 6. AUTHOR(S) Th. Heberer, Dirk Feldmann, Marc Adam, Kirsten...occurrence and the removal of pharmaceutical residues was investigated In a scientific research project (InSan I 1299-V-7502) entitled "Investigation

  8. Techniques for Removing Residual Monomer in Polymer Latex%聚合物乳液中残留单体脱除方法的研究进展

    Institute of Scientific and Technical Information of China (English)

    盛鑫鑫; 谢德龙; 张心亚

    2013-01-01

    聚合物乳液中的残留单体不仅带来环境污染,而且具有强烈的刺激性气味和不同程度的毒性,对使用者的健康造成损害,一定程度上限制了其应用,因此脱除聚合物乳液中的残留单体是聚合物工业中一项重要的措施.脱除残留单体的方法有很多,包括物理方法、化学方法和化学-物理法.文中概述了脱除聚合物乳液中残留单体的各种方法,并就各自的优缺点作了详细的分析,希望为相关研究及工业生产提供借鉴.%Residual monomers in polymer latex not only cause environmental pollution,but also have extremely pungent odor and endanger the user's health,which restricts the application of latex.Removing residual monomer from polymer latex is one of the most important incentives for the polymer industry.There are several techniques,including physical methods,chemical methods and chemical-physical methods.The main objective of this paper is to review the methods employed for removing residual monomer from polymer latex,and make a detailed analysis on their respective advantages and disadvantages,expecting to provide references for the related research and industrial applications.

  9. Effects of ozone fumigation treatment on the removal of residual difenoconazole from strawberries and on their quality.

    Science.gov (United States)

    Heleno, Fernanda F; de Queiroz, Maria Eliana L R; Neves, Antônio Augusto; Freitas, Romenique S; Faroni, Lêda Rita A; De Oliveira, André Fernando

    2014-01-01

    The effect of ozone fumigation on the reduction of difenoconazole residue on strawberries was studied. Strawberries were immersed in 1.0 L of aqueous solution containing 400 μL of the commercial product (250 g L(-1) of difenoconazole) for 1 min. Then, they were dried and exposed to ozone gas (O3) at concentrations of 0.3, 0.6 and 0.8 mg L(-1) for 1 h. The ozone fumigation treatments reduced the difenoconazole residue on strawberries to concentrations below 0.5 mg kg(-1), which corresponds to a 95% reduction. The strawberries treated with ozone and the control group, which was not treated with ozone, were stored at 4°C for 10 days. Some characteristics of the fruit were monitored throughout this period. Among these, pH, weight loss and total color difference did not change significantly (P > 0.05). The fumigation with ozone significantly affected the soluble solids, titratable acidity and ascorbic acid content (vitamin C) of the strawberries preventing a sharp reduction of these parameters during storage.

  10. Adaptive scene-based correction algorithm for removal of residual fixed pattern noise in microgrid image data

    Science.gov (United States)

    Ratliff, Bradley M.; LeMaster, Daniel A.

    2012-06-01

    Pixel-to-pixel response nonuniformity is a common problem that affects nearly all focal plane array sensors. This results in a frame-to-frame fixed pattern noise (FPN) that causes an overall degradation in collected data. FPN is often compensated for through the use of blackbody calibration procedures; however, FPN is a particularly challenging problem because the detector responsivities drift relative to one another in time, requiring that the sensor be recalibrated periodically. The calibration process is obstructive to sensor operation and is therefore only performed at discrete intervals in time. Thus, any drift that occurs between calibrations (along with error in the calibration sources themselves) causes varying levels of residual calibration error to be present in the data at all times. Polarimetric microgrid sensors are particularly sensitive to FPN due to the spatial differencing involved in estimating the Stokes vector images. While many techniques exist in the literature to estimate FPN for conventional video sensors, few have been proposed to address the problem in microgrid imaging sensors. Here we present a scene-based nonuniformity correction technique for microgrid sensors that is able to reduce residual fixed pattern noise while preserving radiometry under a wide range of conditions. The algorithm requires a low number of temporal data samples to estimate the spatial nonuniformity and is computationally efficient. We demonstrate the algorithm's performance using real data from the AFRL PIRATE and University of Arizona LWIR microgrid sensors.

  11. Impact of management strategies on the global warming potential at the cropping system level.

    Science.gov (United States)

    Goglio, Pietro; Grant, Brian B; Smith, Ward N; Desjardins, Raymond L; Worth, Devon E; Zentner, Robert; Malhi, Sukhdev S

    2014-08-15

    Estimating the greenhouse gas (GHG) emissions from agricultural systems is important in order to assess the impact of agriculture on climate change. In this study experimental data supplemented with results from a biophysical model (DNDC) were combined with life cycle assessment (LCA) to investigate the impact of management strategies on global warming potential of long-term cropping systems at two locations (Breton and Ellerslie) in Alberta, Canada. The aim was to estimate the difference in global warming potential (GWP) of cropping systems due to N fertilizer reduction and residue removal. Reducing the nitrogen fertilizer rate from 75 to 50 kg N ha(-1) decreased on average the emissions of N2O by 39%, NO by 59% and ammonia volatilisation by 57%. No clear trend for soil CO2 emissions was determined among cropping systems. When evaluated on a per hectare basis, cropping systems with residue removal required 6% more energy and had a little change in GWP. Conversely, when evaluated on the basis of gigajoules of harvestable biomass, residue removal resulted in 28% less energy requirement and 33% lower GWP. Reducing nitrogen fertilizer rate resulted in 18% less GWP on average for both functional units at Breton and 39% less GWP at Ellerslie. Nitrous oxide emissions contributed on average 67% to the overall GWP per ha. This study demonstrated that small changes in N fertilizer have a minimal impact on the productivity of the cropping systems but can still have a substantial environmental impact.

  12. High residue cover crops alone or with strategic tillage to manage glyphosate-resistant palmer amaranth (amaranthus palmeri) in Southeastern cotton (gossypium hirsutum)

    Science.gov (United States)

    Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Wats) is redefining row crop weed management in the Southeast due to its widespread distribution, high competitive ability, copious seed production, and resilience to standard weed management programs. Herbicides alone are failing to p...

  13. Removal of pharmaceutical residues using ozonation as intermediate process step at Linköping WWTP, Sweden.

    Science.gov (United States)

    Baresel, Christian; Malmborg, Jonas; Ek, Mats; Sehlén, Robert

    2016-01-01

    Pilot tests as basis for the design, implementation and operation of a future full-scale oxidation plant completing the existing sewage treatment in Linköping, Sweden, were performed. Using an ozonation step between bio-sedimentation and post-denitrification processes, the primary goal was the removal of the highest priority substances to effluent water levels that will not cause adverse effects in the recipient considering the natural dilution. The study included initial emission screenings, dose control trials, treatment performance studies and eco-toxicity studies. At an ozone dose of 5 mg O3/L, most substances could be removed. Ecotoxicological tests showed no negative effect for the tested ozone doses. High levels of oxygen into the denitrification could be rapidly reduced in the biology. The number of bacteria in the treated water could be significantly reduced even at relatively low ozone doses. Based on these results, the planning for the full-scale implementation of the treatment system was initiated in 2015.

  14. Soil Organic Carbon Response to Cover Crop and Nitrogen Fertilization under Bioenergy Sorghum

    Science.gov (United States)

    Sainju, U. M.; Singh, H. P.; Singh, B. P.

    2015-12-01

    Removal of aboveground biomass for bioenergy/feedstock in bioenergy cropping systems may reduce soil C storage. Cover crop and N fertilization may provide additional crop residue C and sustain soil C storage compared with no cover crop and N fertilization. We evaluated the effect of four winter cover crops (control or no cover crop, cereal rye, hairy vetch, and hairy vetch/cereal rye mixture) and two N fertilization rates (0 and 90 kg N ha-1) on soil organic C (SOC) at 0-5, 5-15, and 15-30 cm depths under forage and sweet sorghums from 2010 to 2013 in Fort Valley, GA. Cover crop biomass yield and C content were greater with vetch/rye mixture than vetch or rye alone and the control, regardless of sorghum species. Soil organic C was greater with vetch/rye than rye at 0-5 and 15-30 cm in 2011 and 2013 and greater with vetch than rye at 5-15 cm in 2011 under forage sorghum. Under sweet sorghum, SOC was greater with cover crops than the control at 0-5 cm, but greater with vetch and the control than vetch/rye at 15-30 cm. The SOC increased at the rates of 0.30 Mg C ha-1 yr-1 at 0-5 cm for rye and the control to 1.44 Mg C ha-1 yr-1 at 15-30 cm for vetch/rye and the control from 2010 to 2013 under forage sorghum. Under sweet sorghum, SOC also increased linearly at all depths from 2010 to 2013, regardless of cover crops. Nitrogen fertilization had little effect on SOC. Cover crops increased soil C storage compared with no cover crop due to greater crop residue C returned to the soil under forage and sweet sorghum and hairy vetch/cereal rye mixture had greater C storage than other cover crops under forage sorghum.

  15. 吸附法脱除硫酸锰溶液中残余有机物%Removal of Organic Residues in Manganese Sulfate Solution with Adsorption

    Institute of Scientific and Technical Information of China (English)

    王雨红; 粟海锋; 文衍宣

    2013-01-01

    探讨粉煤灰、活性炭和膨润土等吸附剂对硫酸锰溶液中残余少量有机物的吸附效果,并以膨润土为吸附剂进行单因素试验,考察了膨润土用量、吸附时间、pH和温度对吸附效果的影响.结果表明,使用膨润土吸附剂,在溶液pH为7.0,25℃,吸附时间30 min,膨润土用量10.0 g的条件下,硫酸锰溶液的COD去除率可达32.4%;改性膨润土较未改性原土脱除溶液中有机物的效果更好,且酸化改性膨润土优于热化改性膨润土,COD去除率达到40.8%.%The adsorption performance of coal ash, bentonite and activated carbon to removal organic residues in manganese sulfate solution was investigated. Bentonite was chosen as adsorbent for single factor experiment to examine the effects of dosage of bentonite, pH, time and temperature on adsorption. The results show that with bentonite as adsorbent, COD removing rate is 32. 4% under the optimal conditions including pH value of solution of 7. 0 and dosage of bentonite of 10. 0 g for 30 min at 25 ℃. The removal effect on organic matter with modified bentonite is better than that of with unmodified bentonite, and the effect of acidification modified bentonite is better than that of thermalization modified bentonite. The COD removing rate of acidification modified bentonite is 40. 8%.

  16. Removal of the free cysteine residue reduces irreversible thermal inactivation of feruloyl esterase: evidence from circular dichroism and fluorescence spectra.

    Science.gov (United States)

    Li, Jingjing; Zhang, Shuaibing; Yi, Zhuolin; Pei, Xiaoqiong; Wu, Zhongliu

    2015-08-01

    Feruloyl esterase A from Aspergillus niger (AnFaeA) contains three intramolecular disulfide bonds and one free cysteine at position 235. Saturated mutagenesis at Cys235 was carried out to produce five active mutants, all of which displayed unusual thermal inactivation patterns with the most residual activity achieved at 75°C, much higher than the parental AnFaeA. But their optimal reaction temperatures were lower than the parental AnFaeA. Extensive investigation into their free thiol and disulfide bond, circular dichroism spectra and fluorescence spectra revealed that the unfolding of the parental enzyme was irreversible on all the tested conditions, while that of the Cys235 mutants was reversible, and their ability to refold was highly dependent on the denaturing temperature. Mutants denatured at 75°C were able to efficiently reverse the unfolding to regain native structure during the cooling process. This study provided valid evidence that free cysteine substitutions can reduce irreversible thermal inactivation of proteins. © The Author 2015. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

  17. Bioenergy production for CO2-mitigation and rural development via valorisation of low value crop residues and their upgrade into energy carriers: a challenge for sunflower and soya residues.

    Science.gov (United States)

    Zabaniotou, A; Kantarelis, E; Skoulou, V; Chatziavgoustis, Th

    2010-01-01

    The present study concerns the energetic valorization of sunflower and soya residues by air fixed-bed gasification. The main process parameters that have been investigated were the temperature and air equivalence ratio. Experimental results indicated that the high temperature and air had a positive effect in gas yield for both residues by ensuring mild oxidative conditions. Gasification gas composition showed different trends of H(2)/CO ratio for the two residues at low equivalence ratios. The LHV of the produced gas from both residues varied from 6.84 to 12 MJ/Nm(3). The energy recovery achieved via gasification could reach 0.07 and 0.02 per acre of cultivated area for the sunflower and soya residues, respectively, in terms of tons of oil equivalent. Sunflower shown higher oil production and energy recovery than soya did. The results of the present study indicate the viability of alternative energy production from agricultural biomass by gasification. Such residues could comprise an attractive renewable source of energy for covering additional energy demands in agricultural regions through exploitation in small gasification systems.

  18. Response of Sorghum (Sorghum bicolor L.) to Residual Phosphate in Soybean-Sorghum and Maize-Sorghum Crop Rotation Schemes on Two Contrasting Nigerian Alfisols

    OpenAIRE

    2016-01-01

    The effectiveness of finely ground Sokoto Rock Phosphate and Morocco Rock Phosphate to enhance productivity of maize- (Zea mays L.) Sorghum (Sorghum bicolor) and soybean- (Glycine max L.) Sorghum crop rotation schemes was evaluated using Single Super Phosphate as reference fertilizer. The experiments were carried out in the screen house of the Department of Agronomy, University of Ibadan, in February and June 2013. The experiments involved 2 × 2 × 4 × 3 factorial in a Completely Randomized De...

  19. Triosephosphate isomerase: removal of a putatively electrophilic histidine residue results in a subtle change in catalytic mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Nickbarg, E.B.; Davenport, R.C.; Petsko, G.A.; Knowles, J.R.

    1988-08-09

    An important active-site residue in the glycolytic enzyme triosephosphate isomerase is His-95, which appears to act as an electrophilic component in catalyzing the enolization of the substrates. With the techniques of site-directed mutagenesis, His-95 has been replaced by Gln in the isomerase from Saccharomyces cerevisiae. The mutant isomerase has been expressed in Escherichia coli strain DF502 and purified to homogeneity. The specific catalytic activity of the mutant enzyme is less than that of wild type by a factor of nearly 400. The mutant enzyme can be resolved from the wild-type isomerase on nondenaturing isoelectric focusing gels, and an isomerase activity stain shows that the observed catalytic activity indeed derives from the mutant protein. The mutant enzyme shows the same stereospecificity of proton transfer as the wild type. Tritium exchange experiments similar to those used to define the free energy profile for the wild-type yeast isomerase, together with a new method of analysis involving /sup 14/C and /sup 3/H doubly labeled substrates, have been used to investigate the energetics of the mutant enzyme catalyzed reaction. The deuterium kinetic isotope effects observed with the mutant isomerase using (1(R)-/sup 2/H)dihydroxyacetone phosphate and (2-/sup 2/H)glyceraldehyde 3-phosphate are 2.15 +/- 0.04 and 2.4 +/- 0.1, respectively. These results lead to the conclusion that substitution of Gln for His-95 so impairs the ability of the enzyme to stabilize the reaction intermediate that there is a change in the pathways of proton transfer mediated by the mutant enzyme.

  20. Initial responses of rove and ground beetles (Coleoptera, Staphylinidae, Carabidae to removal of logging residues following clearcut harvesting in the boreal forest of Quebec, Canada

    Directory of Open Access Journals (Sweden)

    Timothy Work

    2013-01-01

    Full Text Available Increased interest in biomass harvesting for bioenergetic applications has raised questions regarding the potential ecological consequences on forest biodiversity. Here we evaluate the initial changes in the abundance, species richness and community composition of rove (Staphylinidae and ground beetles (Carabidae, immediately following 1 stem-only harvesting (SOH, in which logging debris (i.e., tree tops and branches are retained on site, and 2 whole-tree harvesting (WTH, in which stems, tops and branches are removed in mature balsam fir stands in Quebec, Canada. Beetles were collected throughout the summer of 2011, one year following harvesting, using pitfall traps. Overall catch rates were greater in uncut forest (Control than either stem-only or whole-tree harvested sites. Catch rates in WTH were greater than SOH sites. Uncut stands were characterized primarily by five species: Atheta capsularis, A. klagesi, A. strigosula, Tachinus fumipennis/frigidus complex (Staphylinidae and to a lesser extent to Pterostichus punctatissimus (Carabidae. Increased catch rates in WTH sites, where post-harvest biomass was less, were attributable to increased catches of rove beetles Pseudopsis subulata, Quedius labradorensis and to a lesser extent Gabrius brevipennis. We were able to characterize differences in beetle assemblages between harvested and non-harvested plots as well as differences between whole tree (WTH and stem only (SOH harvested sites where logging residues had been removed or left following harvest. However, the overall assemblage response was largely a recapitulation of the responses of several abundant species.

  1. 旱地土壤中残留肥料氮的动向及作物有效性%Dynamics and Availability to Crops of Residual Fertilizer Nitrogen in Upland Soil

    Institute of Scientific and Technical Information of China (English)

    王西娜; 王朝辉; 李华; 王荣辉; 谭军利; 李生秀

    2016-01-01

    Objective]Nitrogen is one of the most important and essential elements for growth of crops. Reasonable application of nitrogen fertilizer may promote crop growth and increase its yield,while excessive N fertilization may not only inhibit crop growth,but also leave a large amount of fertilizer nitrogen(N) in the soil as residue,which disturbs balance of soil nutrients and poses a potential threat to the ecological environment. So,it is necessary to study dynamics and availability to crops of the residual N to provide a theoretical basis for rationalizing N fertilization,improving N use efficiency and reducing fertilizer N loss.[Method]To that end,a 4-year stationary field experiment was carried out on a winter wheat and summer maize rotation system,using15N-tracing technique. During the first cycle of the winter wheat and summer maize rotation,240 kg hm-2 of nitrogen was applied in the form of15N-laballed urea in all the plots before winter wheat was sown,in order to make a background of high N residual,and in the following summer maize season,the plots were divided into two groups applied with 0 and 120 kg hm-2 of ordinary urea,separately, at the prolonging stage of the crop to explore effect of N fertilizer application on fertilizer N residue in the soil. During the following three cycles of the rotation,no N fertilizer was applied for analysis of dynamic and availability to the crops of the residual fertilizer N in the soil.[Result]Results show that residue of the15N-laballed N fertilizer that was applied before sowing of winter wheat during the first cycle of the rotation, was found throughout the whole soil profiles of 0~200 cm,after the crop was harvested,and most of that accumulated in the 0~40 cm soil layers. The residue amounted to 200.9 kg hm-2 in total,accounting for 83.7% of the total N fertilizer applied. In the subsequent summer maize growth season,the amount of residual fertilizer N first dropped rapidly,and then declined slowly with the season going

  2. 我国不同地区主要大田作物田间秸秆成熟期%Maturity date of main field crop residues in different regions of China

    Institute of Scientific and Technical Information of China (English)

    韦茂贵; 王晓玉; 谢光辉

    2012-01-01

    秸秆时间分布与作物的成熟期关系密切,对其可持续利用有重要影响。本研究首先提出田间秸秆成熟期的概念,通过查阅2006—2011年正式发表的大田试验文献获得大田作物主产品在各地区的成熟期或收获期,确定不同地区各作物秸秆的成熟期。结果表明:从时间分布上看,1—4月是甘薯、甘蔗、棉花、马铃薯和油菜的秸秆成熟期;5—6月小麦和玉米的秸秆开始成熟,为全国秸秆成熟初期;7—11月为水稻、小麦及玉米集中收获时段,属于秸秆成熟盛期,其中,9和10月秸秆成熟的作物最多;12月为秸秆成熟末期,马铃薯、甘薯、花生、棉花、黄红麻和甘蔗的秸秆在此时期成熟。长江以北地区的作物秸秆成熟期为6—10月,高峰期在8—10月初;长江流域及以南地区无霜期长,可栽培作物种类多,秸秆成熟时间相对分散。明确田间秸秆的成熟期,为研究我国田间秸秆资源的时间分布提供依据。%The temporal distribution of crop residues depends on the crops maturity or harvesting dates,which affects greatly on sustainable residue utilization.Maturity date of crop residues(MDCR)was defined in this article.Maturity date of field crops in different regions of China according to data collected from original papers published mainly between 2006 and 2011 has been analyzed.The MDCR of sweet potato,sugarcane,cotton,potato and canola varied from January to April.The MDCR early stage of wheat and maize was from May to June.The period from July to November was predominant MDCR for rice,wheat and maize.The MDCR of potato,sweet potato,peanut,cotton,Jute and ambary hemp and sugarcane was in December.In the regions located to the north of Yangtze River,the MDCR was between June and October and concentrated from August to October.Due to the long frost-free periods in Yangtze River district and its southern areas of China,field crop residues can be harvested through the whole year.

  3. Nitrogen release from decomposing residues of leguminous cover crops and their effect on maize yield on depleted soils of Bukoba District, Tanzania

    NARCIS (Netherlands)

    Baijukya, F.P.; Ridder, de N.; Giller, K.E.

    2006-01-01

    Nitrogen release patterns from decomposing shoot residues of Tephrosia candida, Crotalaria grahamiana, Mucuna pruriens, Macrotyloma axillare, Macroptillium atropurpureum and Desmodium intortum were studied in the laboratory for a period of 22 weeks in a sandy clay soil and 10 weeks in a clay soil us

  4. Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production – A pot experiment

    Science.gov (United States)

    Byproducts of coal combustion (such as fly ash: FA), livestock industry (such as chicken manure: CM, or animal manure, etc), or water treatment residuals (such as sewage sludge: SS, or incinerated sewage sludge: ISS) can be used as amendments to agricultural soils, provided that these byproducts (ap...

  5. Technological conditions of removing residual soap from alkali refined soybean oil%废白土脱除碱炼脱酸大豆油中残皂工艺条件的研究

    Institute of Scientific and Technical Information of China (English)

    郑彦芳; 魏安池; 代红丽; 赵凯艳; 宋海东

    2015-01-01

    以废白土为吸附剂,对碱炼脱酸大豆油中残皂的脱除进行了研究。在单因素实验的基础上进行响应面优化实验设计,确定了脱皂的最佳工艺条件为:吸附温度82℃,废白土添加量0.5%,吸附时间20 min。在最佳条件下,脱皂大豆油中的残皂量为29.09 mg/kg,脱皂率达91.81%,且短时期(3 d)内存放的废白土脱皂率大于85%。%With waste clay as adsorbent, the removal of residual soap from alkali refined soybean oil was studied. Based on single factor experiment, the optimal conditions of removing residual soap were ob-tained by response surface methodology as follows: adsorption temperature 82℃, dosage of waste clay 0. 5% and adsorption time 20 min. The content of residual soap and the removal rate of residual soap were 29. 09 mg/kg and 91. 81% under these conditions, meanwhile the removal rate of residual soap with short time (3 d) saved waste clay was over 85%.

  6. Environmental and economic evaluation of energy recovery from agricultural and forestry residues

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-01

    Four conversion methods and five residues are examined in this report, which describes six model systems: hydrolysis of corn residues, pyrolysis of corn residues, combustion of cotton-ginning residues, pyrolysis of wheat residues, fermentation of molasses, and combustion of pulp and papermill wastes. Estimates of material and energy flows for those systems are given per 10/sup 12/ Btu of recovered energy. Regional effects are incorporated by addressing the regionalized production of the residues. A national scope cannot be provided for every residue considered because of the biological and physical constraints of crop production. Thus, regionalization of the model systems to the primary production region for the crop from which the residue is obtained has been undertaken. The associated environmental consequences of residue utilization are then assessed for the production region. In addition, the environmental impacts of operating the model systems are examined by quantifying the residuals generated and the land, water, and material requirements per 10/sup 12/ Btu of energy generated. On the basis of estimates found in the literature, capital, operating, and maintenance cost estimates are given for the model systems. These data are also computed on the basis of 10/sup 12/ Btu of energy recovered. The cost, residual, material, land, and water data were then organized into a format acceptable for input into the SEAS data management program. The study indicates that the most serious environmental impacts arise from residue removal rather than from conversion.

  7. Cropping systems with corn residue production levels sufficient to maintain or even improve soil organic carbon levels and allow partial removal for biofuel production

    Science.gov (United States)

    Increasing energy demands and prices, declining petroleum reserves, and political instability in oil-rich areas of the world, all call for greater use of domestically produced biofuels. Recent reports concluded that US agriculture and forest lands have the capacity to produce immense amounts of plan...

  8. BIOGAS PRODUCTION FROM CATCH CROPS

    DEFF Research Database (Denmark)

    Molinuevo-Salces, Beatriz; Larsen, Søren U.; Ahring, Birgitte Kiær

    2014-01-01

    Catch crop cultivation combined with its use for biogas production would increase renewable energy production in the form of methane, without interfering with the production of food and fodder crops. The low biomass yield of catch crops is the main limiting factor for using these crops as co......-substrate in manure-based biogas plants and the profit obtained from the sale of biogas barely compensates for the harvest costs. A new agricultural strategy to harvest catch crops together with the residual straw of the main crop was investigated to increase the biomass and thereby the methane yield per hectare...... biomass. Leaving the straw on the field until harvest of the catch crop in the autumn could benefit biogas production due to the organic matter degradation of the straw taking place on the field during the autumn months. This new agricultural strategy may be a good alternative to achieve economically...

  9. Cover Crop Biomass Harvest Influences Cotton Nitrogen Utilization and Productivity

    Directory of Open Access Journals (Sweden)

    F. Ducamp

    2012-01-01

    Full Text Available There is a potential in the southeastern US to harvest winter cover crops from cotton (Gossypium hirsutum L. fields for biofuels or animal feed use, but this could impact yields and nitrogen (N fertilizer response. An experiment was established to examine rye (Secale cereale L. residue management (RM and N rates on cotton productivity. Three RM treatments (no winter cover crop (NC, residue removed (REM and residue retained (RET and four N rates for cotton were studied. Cotton population, leaf and plant N concentration, cotton biomass and N uptake at first square, and cotton biomass production between first square and cutout were higher for RET, followed by REM and NC. However, leaf N concentration at early bloom and N concentration in the cotton biomass between first square and cutout were higher for NC, followed by REM and RET. Seed cotton yield response to N interacted with year and RM, but yields were greater with RET followed by REM both years. These results indicate that a rye cover crop can be beneficial for cotton, especially during hot and dry years. Long-term studies would be required to completely understand the effect of rye residue harvest on cotton production under conservation tillage.

  10. Fitomassa e decomposição de resíduos de plantas de cobertura puras e consorciadas Biomass and decomposition of cover crop residues in monoculture and intercropping

    Directory of Open Access Journals (Sweden)

    Alexandre Doneda

    2012-12-01

    for cover crop species in consortium. The experiment was conducted in Não-Me-Toque, RS, on an Oxisol, evaluating nine treatments of four cover crops in monoculture [rye (Secale cereale L., oat (Avena strigosa Schreb, pea (Pisum sativum subsp. arvense, and wild radish (Raphanus sativus L. var. oleiferus Metzg] and five in intercropping [(rye + pea, radish + rye, oat + radish, rye + vetch (Vicia sativa L. and oat + vetch]. The decomposition dynamics of cover crop residues was evaluated in litter bags which were distributed on the soil surface and collected after seven, 14, 21, 28, 57, 117, and 164 days. Leguminous and cruciferous intercropped with Gramineae species resulted in greater biomass production compared to cultivation in monoculture. The nitrogen (N accumulated in the pea and wild radish plants intercropped with rye and oat was similar to the N in the leguminous and cruciferous monocultures and exceeded the N values observed for the Gramineae species in monoculture by 220.4 %. By intercropping cover crops it was possible to reduce the decomposition rate of crop residues compared to the monoculture of leguminous and cruciferous species.

  11. Dinâmica do potássio nos resíduos vegetais de plantas de cobertura no Cerrado Potassium dynamics in crop residues of cover plants in Cerrado

    Directory of Open Access Journals (Sweden)

    José Luiz Rodrigues Torres

    2008-08-01

    Full Text Available A produção de biomassa, a manutenção dos resíduos vegetais sobre o solo e sua posterior decomposição são fatores de grande importância no estudo da ciclagem de nutrientes. Este estudo foi desenvolvido na área experimental do CEFET-Uberaba-MG, onde foram avaliados oito tipos de coberturas vegetais: milheto (Pennisetum americanum sin. tiphoydes, braquiária (Brachiaria brizantha, sorgo-forrageiro (Sorghum bicolor L. Moench, guandu (Cajanus cajan (L. Mill sp., crotalária (Crotalarea juncea, aveia-preta (Avena strigosa Schreb, pousio e área em preparo convencional de solo (testemunha em área de Cerrado, na região do Triângulo Mineiro. Avaliaram-se a fitomassa seca (FS, a decomposição dos resíduos em bolsas de decomposição, e a liberação de K. Utilizou-se um modelo matemático para descrever a decomposição dos resíduos e a liberação de K, e calcularam-se a constante de decomposição (k e o tempo de meia-vida (T½. O milheto, o sorgo e a crotalária foram as coberturas que apresentaram maiores produções de matéria seca. O maior acúmulo de K ocorreu em gramíneas e a maior liberação de K ocorreu no milheto, aveia, braquiária e crotalária nos primeiros 42 dias após manejo, nos dois períodos avaliados. A braquiária apresentou o menor T½ vida e a maior taxa de liberação de K.Crop residue production, plant residue maintenance and their decomposition are important factors in the understanding of nutrient recycling process. To evaluate K accumulation and release a study with eight cover crops types was developed: pearl millet (Pennisetum americanum sin. tiphoydes, brachiaria grass (Brachiaria brizantha, sorghum (Sorghum bicolor L. Moench, pigeonpea (Cajanus cajan (L. Millsp, sunn hemp (Crotalarea juncea and black oats (Avena strigosa Schreb, fallow land and conventional culture (control in the experimental area of CEFET-Uberaba-MG, in a Cerrado area. The dry mass production, crop residue decomposition in litter bags

  12. Cover crop effects on soil carbon and nitrogen under bioenergy sorghum crops

    Science.gov (United States)

    Cover crops can increase soil C and N storage and reduce the potential for N leaching under agronomic crops, but information on their benefits under bioenergy crops is scanty due to the removal of aboveground biomass. The objective of the study was to evaluate the effect of cover crops on soil organ...

  13. 加氢处理温度对渣油中杂质脱除率的影响%Effect of Hydrotreating Temperature on Impurity Removal Efficiency of Residue

    Institute of Scientific and Technical Information of China (English)

    王跃; 张会成; 马波; 凌凤香; 孙万付

    2011-01-01

    The reside hydro-processing pilot plant was used to investigate property changes of residue before and after hydrotreatment at different temperatures, and removal rates and distribution laws of sulfur, nitrogen, nickel, vanadium and carbon residue were studied. The result shows that, at constant temperature, contents of sulfur, nitrogen, nickel, vanadium and carbon residue in hydrotreated residue decrease as the activity of catalysts is enhanced; impurity contents in hydrotreated residue decrease as the reaction temperature rises. The total removal efficiency of sulfur, nitrogen, nickel, vanadium and carbon residue increases as the reaction temperature rises. But, removal efficiency of impurities in different reactors is different. 50% of nickel and 60% of vanadium are removed in reactor No.1 and reactor No.2. Sulfur is mainly removed in reactor No.3 and reactor No.4. Nitrogen is mainly removed in reactor No.4 and reactor No.S. Carbon residue is removed in reactor No.l, reactor No.3 and reactor No.4. The removal efficiency of different impurities presents respective regulation with the temperature change.%利用渣油加氢中试装置,考察了原料渣油在不同反应温度下经级配催化剂加氢处理前后渣油性质的变化,揭示了硫、氮、镍、钒和残炭的脱除分布规律.结果表明,在恒定温度下,随催化剂活性增加,加氢处理渣油中硫、氮、镍、钒和残炭的含量降低;随反应温度升高,同一反应器得到的渣油杂质含量降低.硫、氮、镍、钒和残炭的总脱除率随反应温度增加而增加,但杂质在各反应器中的脱除率分布不同,50%的镍和60%的钒在前两个反应器中脱除,硫主要在R3和R4反应器中脱除,氮主要在R4和R5反应器中脱除,而残炭则在R1、R3和R4反应器中脱除,随温度变化杂质的脱除率分布呈现各自的变化趋势.

  14. Total organic and residual carbon contents of oxissol under diferents crop systems / Efeitos dos sistemas de manejo sobre o carbono orgânico total e carbono residual de um latossolo vermelho eutroférrico

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Guimarães

    2009-07-01

    Full Text Available The soil degradation is related to inadequate use of tillage systems, which result in decrease of organic matter content, chemical fertility and physical attributes. The no-tillage system is effective in protection of the soil surface. This study aimed to evaluate the carbon content of the oxissol under conventional tillage, no-tillage and pasture systems, using a secondary forest in regeneration as reference. As smaller the mobilization and larger the maintenance in soil of the vegetable residue, larger were the content of organic carbon and of residual carbon.A degradação dos solos é atribuída à utilização de sistemas de manejo inadequados, do qual resulta a diminuição da matéria orgânica, da fertilidade química e de atributos físicos. O plantio direto é eficaz na proteção da superfície do solo devido à deposição dos resíduos culturais. Este trabalho teve por objetivo avaliar o carbono orgânico total e residual de um Latossolo Vermelho eutroférrico sob os sistemas de manejo convencional, plantio direto e pasto, utilizando uma mata secundária em processo de regeneração como referência. Quanto menor a mobilização e maior a manutenção dos resíduos vegetais sobre o solo, maiores foram os teores de carbono orgânico total e de carbono residual.

  15. Detoxification of Olive Mill Wastewater and Bioconversion of Olive Crop Residues into High-Value-Added Biomass by the Choice Edible Mushroom Hericium erinaceus.

    Science.gov (United States)

    Koutrotsios, Georgios; Larou, Evangelia; Mountzouris, Konstantinos C; Zervakis, Georgios I

    2016-09-01

    Environmentally acceptable disposal of olive cultivation residues (e.g., olive prunings; olive pruning residues (OLPR)) and olive mill wastes is of paramount importance since they are generated in huge quantities within a short time. Moreover, olive mill wastewater (OMW) or sludge-like effluents ("alperujo"; two-phase olive mill waste (TPOMW)) are highly biotoxic. Hericium erinaceus is a white-rot fungus which produces choice edible mushrooms on substrates rich in lignocellulosics, and its suitability for the treatment of olive by-products was examined for the first time. Fungal growth resulted in a notable reduction of OMW's pollution parameters (i.e., 65 % decolorization, 47 % total phenolic reduction, and 52 % phytotoxicity decrease) and correlated with laccase and manganese peroxidase activities. Solid-state fermentation of various mixtures of OLPR, TPOMW, and beech sawdust (control) by H. erinaceus qualified OLPR in subsequent cultivation experiments, where it exhibited high mushroom yields and biological efficiency (31 %). Analyses of proximate composition and bioactive compound content revealed that mushrooms deriving from OLPR substrates showed significantly higher crude fat, total glucan, β-glucan, total phenolics, and ferric-reducing antioxidant potential values than the control. H. erinaceus demonstrated the potential to detoxify OMW and bioconvert OLPR into high-quality biomass, and hence, this fungus could be successfully exploited for the treatment of such by-products.

  16. Possibilities of using steelmaking industry residues in the removal of metals from liquid effluents; Posibilidades sobre el uso de residuos de la industria del acero en la elimiancion de metales de efluentes liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M. I.; Lopez, F. A.; Lopez-Delgado, A.; Perez, C.; Alguacil, F. J.

    2004-07-01

    A study is made of the removal of metals present in aqueous effluents using a residue of the steelmaking industry deaminated rolling mill scale. Mill scale can be considered a cheap materials for the removal of toxic metals due to its high content in iron oxides and metallic iron. A study of the removal of Cd2+, Zn2+, Pb2+, Cu2+ ions from aqueous solutions was made, studying several variables that effect the process. The removal of cadmium, zinc and lead corresponding to a superficial adsorption process, was evaluated using the theories of Langmuir and Freundlich. The removal of copper occurs thorough a process of oxidation-reduction or cementation (Cu''2+/Fe''0). The possibilities of desorption were studied too. (Author) 18 refs.

  17. Use of post-harvest sugarcane residue for ethanol production.

    Science.gov (United States)

    Dawson, Letha; Boopathy, Raj

    2007-07-01

    Agricultural residues are produced in large quantities throughout the world. Approximately, 1kg of residue is produced for each kilogram of grains harvested. This ratio of grain/residue translates into an excess of 40 billion ton of crop residue produced each year in the USA. These residues are renewable resources that could be used to produce ethanol and many other value added products. In this study, we demonstrate that the post-harvest sugar cane residue could be used to produce fuel grade ethanol. A chemical pre-treatment process using alkaline peroxide or acid hydrolysis was applied to remove lignin, which acts as physical barrier to cellulolytic enzymes. Yeast Saccharomyces cerevisiae ATCC strain 765 was used in the experiment. The pre-treatment process effectively removed lignin. Ethanol production in the culture sample was monitored using high performance liquid chromatography. The results indicate that ethanol can be made from the sugarcane residue. The fermentation system needs to be optimized further to scale up the process for large-scale production of ethanol from sugar cane residue.

  18. Determination of sulfosulfuron residues in soil under wheat crop by a novel and cost-effective method and evaluation of its carryover effect.

    Science.gov (United States)

    Singh, Shashi B; Kulshrestha, Gita

    2007-01-01

    A novel and cost-effective method of sulfosulfuron extraction has been developed using distilled water as an extraction solvent. Using this method, the environmental fate of sulfosulfuron was investigated in soil under wheat crop. Studies were conducted under natural field conditions in randomized block design and herbicide (75% water dispersible granules (WG)) was applied after 24 days of sowing. The rates of applications were 25 and 50 g of active ingredient (a.i.) per hectare. Soil samples were collected at predetermined intervals and analyzed by high performance liquid chromatography (HPLC). The minimum detection limit was found to be 0.001 micro g g(-1). The dissipation of sulfosulfuron followed first-order rate kinetics and dissipated with a half-life of 5.4-6.3 days. After harvest, field soil was used for conducting a pot experiment with bottle gourd (Lagenaria siceraria) as test plants to study the carry over effect of sulfosulfuron. No phytotoxicity was observed to bottle gourd in pot experiment with harvest soil.

  19. Characterization of fine and carbonaceous particles emissions from pelletized biomass-coal blends combustion: Implications on residential crop residue utilization in China

    Science.gov (United States)

    Xu, Yue; Wang, Yan; Chen, Yingjun; Tian, Chongguo; Feng, Yanli; Li, Jun; Zhang, Gan

    2016-09-01

    Bulk biofuel, biomass pellets and pelletized biomass-coal blends were combusted in a typical rural conventional household stove and a high-efficiency stove. Reductions in PM2.5, organic carbon (OC) and elemental carbon (EC) emissions were evaluated by comparing emission factors (EFs) among 19 combinations of biofuel/residential stove types measured using a dilution sampling system. In the low-efficiency stove, the average EFs of PM2.5, OC, and EC of biomass pellets were 2.64 ± 1.56, 0.42 ± 0.36, and 0.30 ± 0.11 g/kg, respectively, significantly lower than those burned in bulk form. EFPM2.5 and EFOC of pelletized biomass combustion in the high-efficiency stove were lower than those of the same biofuel burned in the low-efficiency stove. Furthermore, pelletized corn residue and coal blends burned in the high-efficiency stove could significantly decrease emissions. Compared with the bulk material burned in the low-efficiency stove, the reduction rates of PM2.5, OC and EC from pelletized blends in the high-efficiency stove can reach 84%, 96% and 93%, respectively. If the annually produced corn residues in 2010 had been blended with 10% anthracite coal powder and burnt as pellets, it would have reduced about 82% of PM2.5, 90-96% of OC and 81-92% of EC emission in comparison with burning raw materials in conventional household stoves. Given the low cost, high health benefit and reduction effect on atmospheric pollutants, pelletized blends could be a promising alternative to fossil fuel resources or traditional bulk biofuel.

  20. Grain legumes in organic cropping systems

    OpenAIRE

    Hauggaard-Nielsen, Dr. Henrik

    2002-01-01

    Grain legumes are valuable protein and energy sources in animal feeds and in human diets low in meat. Furthermore, grain legumes strongly benefit the cropping system, via biological fixation of atmospheric N2 - a fundamental process for maintaining soil fertility in organic farming systems. Other positive effects in the crop rotations are recycled N-rich crop residues and the break-crop effect in cereals-rich rotations. However, yield variability in grain legumes is well known and related to...

  1. The PIP training programme: building of ACP experts capacities in crop protection and food safety to support local companies to comply with EU regulations on pesticides residues.

    Science.gov (United States)

    Schiffers, B C; Schubert, A; Schiffers, C; Fontaine, S; Gumusboga, N; Werner, B; Webb, M; Lugros, H; Stinglhamber, G

    2006-01-01

    Regulatory requirements, and in particular phytosanitary quality standards change rapidly. As ACP producers/exporters race to become more competitive, to keep their market share and to satisfay their customers' commercial demands (e.g. EUREP-GAP certification), the need for competent staff who are aware of the company's quality objectives and trained to follow instructions is crucial. Mastering sanitary quality is only possible if matched with a programme to build the skills of companies' human resources. The Pesticide Initiative Programme (PIP), mindful of the importance of making operators autonomous and of training them to monitor EU food safety regulations and technology on their own, has successfully developed a training programme while building a quality network of local/ACP service providers. By building the capacities of ACP experts and then securing their services as trainers, PIP also guarantees companies' access to expertise and the sustainability of their efforts to comply with new EU regulations. The training strategy developed by PIP rests on two pilars: instructor training and collective training. Instructor training consists in reinforcing the technical knowledge of local experts (agronomists, hygienists, etc.) by providing them with active teaching methods. Once the ACP experts have gained enough technical knowledge of the key areas of crop protection--mainly pesticides management--and food safety, and have demonstrated their capacity to train the technical staff of local companies, the PIP has carried out a collective training programme in 2004, 2005 and 2006. To date, more than 130 consultants covering about 15 ACP countries have received instructor training, and more than 700 people have participated in collective and in-company training sessions.

  2. Carbon and nutrient losses during manure storage under traditional and improved practices in smallholder crop-livestock systems - evidence from Kenya

    NARCIS (Netherlands)

    Tittonell, P.A.; Rufino, M.C.; Janssen, B.H.; Giller, K.E.

    2010-01-01

    In the absence of mineral fertiliser, animal manure may be the only nutrient resource available to smallholder farmers in Africa, and manure is often the main input of C to the soil when crop residues are removed from the fields. Assessments of C and nutrient balances and cycling within

  3. Electrodialytic removal of heavy metals and chloride from municipal solid waste incineration fly ash and air pollution control residue in suspension - test of a new two compartment experimental cell

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Magro, Cátia; Guedes, Paula

    2015-01-01

    of MSWI residues in for instance concrete, the aim of remediation should be reduction of the heavy metal leaching, while at the same time keeping the alkaline pH, so the residue can replace cement. In this study a MSWI residues were subjected to electrodialytic remediation under various experimental...... conditions. Also a newly developed 2 compartment experimental cell was tested. The results show that the pH development in the MSWI residue suspension depended on the type of MSWI residue and the experimental cell type. The acidification of the suspension occurred earlier when using the 2 compartment setup...... and the acidification of the fly ash occurred earlier than for the APC residue but the highest removal was seen with the 3 compartment cell. The lowest final pH for the fly ash and APC residue was 6.4 and 10.9, respectively. The results showed that the leaching of Cd, Cu, Pb and Zn was reduced compared to the initial...

  4. Caracterização das perdas e distribuição de cobertura vegetal em colheita mecanizada de soja Characterization of losses and crop residue cover distribution in soybean mechanized harvest

    Directory of Open Access Journals (Sweden)

    Anderson de Toledo

    2008-12-01

    Full Text Available O conceito de controle de qualidade nas operações inserido na agricultura é viabilizado por incidir diretamente nos principais objetivos do processo produtivo: retorno econômico e aumento da produtividade. A colheita mecanizada normalmente é realizada sem que haja controle efetivo para que a variabilidade das perdas fique dentro de padrões aceitáveis. Esta pesquisa teve o objetivo de determinar e caracterizar as perdas e a distribuição da cobertura vegetal após a colheita mecanizada da soja, por meio de ferramenta de controle estatístico de processo (cartas de controle. A média da perda de grãos total foi próxima do limite superior aceitável para a cultura da soja, apresentando alta variabilidade entre os pontos, tornando o processo fora de controle. A distribuição de cobertura vegetal manteve-se em processo controlado, com maior variabilidade onde o relevo foi mais inclinado. A utilização das cartas de controle foi eficiente na identificação dos pontos fora de controle e na avaliação da qualidade do processo de colheita.The concept of operation control inserted in agriculture is made possible by making a directly influence in the main objectives of productive process, economic return and increase of productivity. The mechanized harvest normally is carried out without an effective control of the variability of losses so that it maintains acceptable standards. This research aimed to determinate and characterize the losses and crop residue cover distribution after soybean mechanized harvest, using the tool of statistical process control (control charts. The average of total grain losses was near the upper limit specified for losses in soybean, showing high variation between points, and putting the process out of control. The residue crop cover distribution stayed under control process, with greater variability where the terrain was more sloping. The use of control charts was efficient to identify the points out of control

  5. feasibility of winter cover crop production under rainfed conditions in ...

    African Journals Online (AJOL)

    ACSS

    Low winter rainfall poses a challenge to production of high biomass from cover ... February planted cover crops had the lowest residues remaining at maize ..... Interaction effects of planting date and cover crop species on cover crop dry weight at termination in Eastern Cape ... to weed species density (per m2) at cover crop.

  6. Soil carbon and crop yields affected by irrigation, tillage, crop rotation, and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  7. Characterizing pesticide dissipation in food crops

    DEFF Research Database (Denmark)

    Fantke, Peter; Juraske, R.; Jolliet, O.

    2013-01-01

    Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure. Neverth......Ingestion of residues via consumption of food crops is the predominant exposure route of the general population toward pesticides. However, pesticide dissipation in crops constitutes a main source of uncertainty in estimating residues in harvested crop parts and subsequent human exposure....... Nevertheless, dissipation is a key mechanism in models assessing pesticide distribution in the cropenvironment and the magnitude of residues in harvest. We provide a consistent framework for characterizing pesticide dissipation in food crops for use in modeling approaches applied in health risk and impact...... assessment. We collected 4,482 unique dissipation half-lives for 341 substances applied to 182 different crop species and fully characterize these data by describing their variance, distribution and uncertainty as well as by identifying the influence of substance, crop and environmental characteristics. We...

  8. Redução da infestação de Brachiaria plantaginea em soja pela cobertura do solo com palha de aveia-preta Reduction of Brachiaria plantaginea infestation on soybean crop with black oat residues

    Directory of Open Access Journals (Sweden)

    GIOVANI THEISEN

    2000-04-01

    infestation occurred on the crop row than between the rows. In the weed-free treatments, soybean yield was not affected by crop residues. On the other hand, soybean yield increased linearly with increased amount of black oat residues on the soil controlling the weed. In weedy areas, soybean yield increased at the rate of 158 kg/ha for each ton of straw on the soil surface.

  9. Tillage and crop residue management methods had minor effects on the stock and stabilization of topsoil carbon in a 30-year field experiment.

    Science.gov (United States)

    Singh, Pooja; Heikkinen, Jaakko; Ketoja, Elise; Nuutinen, Visa; Palojärvi, Ansa; Sheehy, Jatta; Esala, Martti; Mitra, Sudip; Alakukku, Laura; Regina, Kristiina

    2015-06-15

    We studied the effects of tillage and straw management on soil aggregation and soil carbon sequestration in a 30-year split-plot experiment on clay soil in southern Finland. The experimental plots were under conventional or reduced tillage with straw retained, removed or burnt. Wet sieving was done to study organic carbon and soil composition divided in four fractions: 1) large macroaggregates, 2) small macroaggregates, 3) microaggregates and 4) silt and clay. To further estimate the stability of carbon in the soil, coarse particulate organic matter, microaggregates and silt and clay were isolated from the macroaggregates. Total carbon stock in the topsoil (equivalent to 200 kg m(-2)) was slightly lower under reduced tillage (5.0 kg m(-2)) than under conventional tillage (5.2 kg m(-2)). Reduced tillage changed the soil composition by increasing the percentage of macroaggregates and decreasing the percentage of microaggregates. There was no evidence of differences in the composition of the macroaggregates or carbon content in the macroaggregate-occluded fractions. However, due to the higher total amount of macroaggregates in the soil, more carbon was bound to the macroaggregate-occluded microaggregates in reduced tillage. Compared with plowed soil, the density of deep burrowing earthworms (Lumbricus terrestris) was considerably higher under reduced tillage and positively associated with the percentage of large macroaggregates. The total amount of microbial biomass carbon did not differ between the treatments. Straw management did not have discernible effects either on soil aggregation or soil carbon stock. We conclude that although reduced tillage can improve clay soil structure, generally the chances to increase topsoil carbon sequestration by reduced tillage or straw management practices appear limited in cereal monoculture systems of the boreal region. This may be related to the already high C content of soils, the precipitation level favoring decomposition and

  10. Rational management of tobacco (Nicotiana tabacum L. crop residues to obtain organic compostManejo racional de resíduos da cultura do fumo (Nicotiana tabacum L. para obtenção de composto orgânico

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Souza Borges Filho

    2011-10-01

    Full Text Available Crop residues may be used to produce organic composts for agricultural use. The aim of this study was to evaluate the effect of two inoculums on the decomposition speed of tobacco residues (stems. The experiment was carried out in a completely randomized design, with three treatments and six replications. The residue used in the study was passed through a forage chopper and mixed to the inoculums in a concrete truck mixer. The treatments evaluated were: TF + EB + RB - tobacco residue, bovine manure and bovine rumen; TF + EB + MP - tobacco residue, bovine manure and Microsept-Dust and TF + EB - tobacco residue and bovine manure. The temperature and humidity of the piles were monitored weekly. The piles were initially turned up side down every seven days, and then every fourteen days till closing 60 days. Samples for chemical analysis of the composted material were collected at 30, 60 and 90 days after the beginning of the composting process. The temperature of the piles stayed around 57 to 60 ºC in the period between the 20 to 40 days after the beginning of the composting process. The mix containing cattle rumen (RB presented the lowest temperature after forty days. At the end of the composting the mix containing Microsept-Dust (MP presented the lowest humidity. The C/N relation of the composts obtained was around 10/1 and 11/1. The three treatments presented pH values close to the neutrality in the mature stage. A period of sixty days seems to be sufficient to obtain a mature and stable biocompost of tobacco waste using manure independent of the addition of inoculums.Os resíduos vegetais podem ser utilizados na produção de adubo orgânico por meio da compostagem. O objetivo deste estudo foi avaliar o efeito de dois inoculantes sobre a velocidade de decomposição do resíduo da cultura do fumo. O experimento foi conduzido em delineamento inteiramente casualizado, com três tratamentos e seis repetições, sendo o resíduo picado em picadeira

  11. Analysis of organic farming practices amongst crop farmers in Delta ...

    African Journals Online (AJOL)

    Dr. atoma & Family

    The farming practice is eco-friendly and works in agreement with nature. ... Lampkin (1990), said that organic farming systems rely on crop rotation, crop residues, .... The study revealed high-level awareness of organic farming practices but ...

  12. Trace gas emissions from combustion of peat, crop residue, domestic biofuels, grasses, and other fuels: configuration and Fourier transform infrared (FTIR) component of the fourth Fire Lab at Missoula Experiment (FLAME-4)

    Science.gov (United States)

    Stockwell, C. E.; Yokelson, R. J.; Kreidenweis, S. M.; Robinson, A. L.; DeMott, P. J.; Sullivan, R. C.; Reardon, J.; Ryan, K. C.; Griffith, D. W. T.; Stevens, L.

    2014-09-01

    During the fourth Fire Lab at Missoula Experiment (FLAME-4, October-November 2012) a large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high-resolution mass spectrometry, one- and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR) spectroscopy. This paper summarizes the overall experimental design for FLAME-4 - including the fuel properties, the nature of the burn simulations, and the instrumentation employed - and then focuses on the OP-FTIR results. The OP-FTIR was used to measure the initial emissions of 20 trace gases: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. These species include most of the major trace gases emitted by biomass burning, and for several of these compounds, this is the first time their emissions are reported for important fuel types. The main fire types included African grasses, Asian rice straw, cooking fires (open (three-stone), rocket, and gasifier stoves), Indonesian and extratropical peat, temperate and boreal coniferous canopy fuels, US crop residue, shredded tires, and trash. Comparisons of the OP-FTIR emission factors (EFs) and emission ratios (ERs) to field measurements of biomass burning verify that the large body of FLAME-4 results can be used to enhance the understanding of global biomass burning and its representation in atmospheric chemistry models. Crop residue fires are widespread globally and account for the most burned area in the US, but their emissions were previously poorly characterized. Extensive results are presented for burning rice and wheat straw: two major global crop residues

  13. Comparison of veterinary drug residue results in animal tissues by ultrahigh-performance liquid chromatography coupled to triple quadrupole ... use of a commercial lipid removal product

    Science.gov (United States)

    Veterinary drug residues in animal-derived foods must be monitored to ensure food safety, verify proper veterinary practices, enforce legal limits in domestic and imported foods, and other purposes. A common goal in drug residue analysis in foods is to achieve acceptable monitoring results for as m...

  14. Modelling pesticides residues

    OpenAIRE

    2004-01-01

    This work is a contribution to the development of a specific method to assess the presence of residues in agricultural commodities. The following objectives are formulated: to identify and describe main processes in environment — plant exchanges, to build of a model to assess the residue concentration at harvest in agricultural commodities, to understand the functioning of the modelled system, to characterise pesticides used in field crops and identify optimisation potentials in phytosanitary...

  15. CROPS Clever Robots for Crops

    NARCIS (Netherlands)

    Bontsema, J.; Hemming, J.; Pekkeriet, E.J.

    2015-01-01

    In the EU-funded CROPS project robots are developed for site-specific spraying and selective harvesting of fruit
    and fruit vegetables. The robots are being designed to harvest crops, such as greenhouse vegetables, apples,
    grapes and for canopy spraying in orchards and for precision target sp

  16. AP1000非能动换热器数值模拟%Numerical simulation of AP1000 passive residual heat removal heat exchanger

    Institute of Scientific and Technical Information of China (English)

    薛若军; 王明远; 李朝君; 祝贺

    2012-01-01

    To accurately know heat transfer and flow processes of AP1000 passive residual heat removal heat exchanger( PRHR HX) , and provide a reference for the safe operation of our new AP1000 advanced pressurized water reactor nuclear power plant, FLUENT software is used. By comparative analysis of the distribution of temperature-field and flow-field in different locations at the same time, and the change of temperature-field and flow-field in the same location at different times, we can know the heat transfer and~flow characteristics which are changed with time more intuitive, and analyze the effect of straight tubes and elbow tubes on the natural circulation. The results show that the temperature difference, vortex, flow around make the interaction of temperature field and flow field. Due to the influence of elbow tubes structure, the fluid natural convection in the IRWST is more complex.%为准确认识AP1000非能动余热排出热交换器的具体换热和流动过程,针对AP1000非能动换热器,应用FLUENT软件对其非稳态传热特性和流动进行研究,比较分析同一时刻不同位置温度场和流场的分布,以及不同时刻同一位置温度场和流场的变化,分析换热器传热和流动特性随时间的变化,同时对比分析直管形管束和弯形管束对换热器自然对流的影响.分析结果表明:温差、漩涡和回流使温度场和流场相互影响,弯形管束使流体自然对流更加复杂.研究成果有助于分析换热器的自然循环能力,为我国新建的AP1000先进压水堆核电机组的安全运行提供参考.

  17. Application of N-methylmorpholine N-oxide in removing ramie residual gum%N-甲基吗啉-N-氧化物去除苎麻残胶研究

    Institute of Scientific and Technical Information of China (English)

    蔡映杰; 林丽娜; 李进; 李海燕; 曾庆福

    2011-01-01

    苎麻生物脱胶后的残胶影响其后续纺纱加工.在不损伤纤维素的前提下,采用绿色环保且可回收的N-甲基吗啉-N-氧化物(NMMO)水溶液对苎麻生物脱胶麻的残胶进行处理,考察w(NMMO)、温度、时间和浴比对去除苎麻残胶的影响.结果表明,苎麻在w(NMMO)=50%,70℃,浴比1∶20水浴加热60min条件下,残胶率达到最低(2.28%).%Residual gum in the bio-degumming ramie fibers could affect the subsequent spinning process. Under the premise of undamaging the cellulose fiber, green and recycled N-methylmorpholine N-oxide (NMMO) solution was applied to remove the residual gum in the bio-degumming ramie. The effects of NMMO concentration, reaction temperature, reaction time and liquor ratio on the residual gum removal were investigated. The results showed that the lowest residual gum 2.28% was obtained under the optimum conditions: 50% of NMMO, 1:20 of liquor ratio, heated at 70 ℃ for 60 min.

  18. The efficacy of the Self-Adjusting File versus WaveOne in removal of root filling residue that remains in oval canals after the use of ProTaper retreatment files: A cone-beam computed tomography study

    Directory of Open Access Journals (Sweden)

    Ajinkya M Pawar

    2016-01-01

    Full Text Available Aim: The current ex vivo study compared the efficacy of removing root fillings using ProTaper retreatment files followed by either WaveOne reciprocating file or the Self-Adjusting File (SAF. Materials and Methods: Forty maxillary canines with single oval root canal were selected and sectioned to obtain 18-mm root segments. The root canals were instrumented with WaveOne primary files, followed by obturation using warm lateral compaction, and the sealer was allowed to fully set. The teeth were then divided into two equal groups (N = 20. Initial removal of the bulk of root filling material was performed with ProTaper retreatment files, followed by either WaveOne files (Group 1 or SAF (Group 2. Endosolv R was used as a gutta-percha softener. Preoperative and postoperative high-resolution cone-beam computed tomography (CBCT was used to measure the volume of the root filling residue that was left after the procedure. Statistical analysis was performed using t-test. Results: The mean volume of root filling residue in Group 1 was 9.4 (±0.5 mm 3 , whereas in Group 2 the residue volume was 2.6 (±0.4 mm 3 , (P < 0.001; t-test. Conclusions: When SAF was used after ProTaper retreatment files, significantly less root filling residue was left in the canals compared to when WaveOne was used.

  19. 非能动余热排出换热器换热能力数值分析%Numerical Analysis on Heat Removal Capacity of Passive Residual Heat Removal Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    张文文; 丛腾龙; 田文喜; 秋穗正; 苏光辉; 谢永诚; 蒋兴

    2015-01-01

    Thermal‐hydraulics characteristics of AP1000 passive residual heat removal heat exchanger (PRHR‐HX) at initial operating stage were analyzed based on the por‐ous media model .The data obtained from RELAP5 under the condition of the station blackout was employed as the inlet flow rate and temperature boundary of CFD calcula‐tion .The distribution resistances were added into the C‐type tube bundle region which was treated as porous zone .Three‐dimensional distributions of velocity and temperature in the in‐containment refueling water storage tank (IRWST ) were calculated by the commercial CFD code FLUENT .The heat transfer between the primary loop side and the IRWST side was calculated by user self‐defined function UDF .The results show that the heat transfer capability decreases with the increase of water temperature and a thermal stratification phenomenon in the tank occurs .The present results indicate that the method containing coupled heat transfer from the primary loop side fluid to IRWST side fluid and porous media model is a suitable approach to study the transient thermal‐hydraulics of PRHR/IRWST system .%基于多孔介质模型,对AP1000非能动余热排出换热器(PRHR‐HX)运行初始阶段进行了数值模拟。一回路的入口温度及流量采用RELAP5的计算结果,并以此作为CFD计算的边界条件。采用多孔介质模型处理C型管束区,添加管束区分布阻力。通过商业CFD软件FLUENT 计算得到安全壳内置换料水箱(IRWST )侧冷却剂的三维温度及速度分布,通过用户自定义函数 UDF 完成一回路侧与IRWST侧的耦合换热计算,获得一回路温度分布及换热量。计算结果表明,随着IRWST 内冷却剂温度升高,换热器热负荷降低,并出现明显的热分层现象,同时证明采用多孔介质模型与耦合换热计算是分析PRHR/IRWST系统瞬态热工水力特性的有效方法。

  20. CROP FARMIERS

    African Journals Online (AJOL)

    however, their success in addressing the credit needs of food crop farmers remains a ..... will to carry such policies through in the match .... farmer, his mental capacity to cope with the daily .... had stated that farm level credit when properly.

  1. Environmental and economic evaluations of energy recovery from agricultural and forestry residues

    Energy Technology Data Exchange (ETDEWEB)

    Harper, J.P.; Antonopoulos, A.A.; Sobek, A.A.

    1979-08-01

    Agricultural and forestry residues have been converted to energy for centuries. The technologies employed range from straightforward approaches such as combustion to produce heat to more involved approaches such as pyrolysis of the residues to produce medium-Btu synthetic gas, charcoal, and oil. Thus there is no one technology that can be characterized as the best or most promising for conversion of agricultural and forestry residues into energy. Therefore, to accurately assess the potential of agricultural and forestry residues as energy resources, an array of current conversion options should be addressed. Four conversion methods and five residues are examined in this report, which describes six model systems: hydrolysis of corn residues, pyrolysis of corn residues, combustion of cotton-ginning residues, pyrolysis of wheat residues, fermentation of molasses, and combustion of pulp and papermill wastes. Estimates of material and energy flows for those systems are given per 10/sup 12/ Btu of recovered energy. Regional effects are incorporated by addressing the regionalized production of the residues. A national scope cannot be provided for every residue considered because of the biological and physical constraints of crop production. Thus, regionalization of the model systems to the primary production region for the crop from which the residue is obtained has been undertaken. The associated environmental consequences of residue utilization are then assessed for the production region. In addition, the environmental impacts of operating the model systems ae examined. On the basis of estimates found in the literature, capital, operating, and maintenance cost estimates are given for the model systems. The study indicates that the most serious environmental impacts arise from residue removal rather than from conversion.

  2. Assessing plant residue decomposition in soil using DRIFT spectroscopy

    Science.gov (United States)

    Ouellette, Lance; Van Eerd, Laura; Voroney, Paul

    2016-04-01

    Assessment of the decomposition of plant residues typically involves the use of tracer techniques combined with measurements of soil respiration. This laboratory study evaluated use of Diffuse Reflectance Fourier Transform (DRIFT) spectroscopy for its potential to assess plant residue decomposition in soil. A sandy loam soil (Orthic Humic Gleysol) obtained from a field research plot was passed through a 4.75 mm sieve moist (~70% of field capacity) to remove larger crop residues. The experimental design consisted of a randomized complete block with four replicates of ten above-ground cover crop residue-corn stover combinations, where sampling time was blocked. Two incubations were set up for 1) Drift analysis: field moist soil (250 g ODW) was placed in 500 mL glass jars, and 2) CO2 evolution: 100 g (ODW) was placed in 2 L jars. Soils were amended with the plant residues (oven-dried at 60°C and ground to polysaccharides at 1106 and 1036 cm-1. Evolved CO2 was measured by the alkali trap method (1 M NaOH); the amount of plant residue-C remaining in soil was calculated from the difference in the quantity of plant residue C added and the additional CO2-C evolved from the amended soil. First-order model parameters of the change in polysaccharide peak area over the incubation were related to those generated from the plant residue C decay curves obtained from respiration measurements. The DRIFT method demonstrated that spectral areas consistent with labile aliphatic-C bands (2930 cm-1) can also be used to describe residue C decomposition. This is the first study to demonstrate the usefulness of DRIFT spectroscopy to characterize plant decomposition in soil.

  3. Effects of Tillage and Crop Residues Incorporation on Spring Maize Yield and Physical and Chemical Properties of Soil%耕作及秸秆还田方式对春玉米产量及土壤理化性状的影响

    Institute of Scientific and Technical Information of China (English)

    战秀梅; 彭靖; 李秀龙; 李亭亭; 韩晓日; 宋涛; 潘全良

    2014-01-01

    A 2-year located field plot experiment was conducted to study the influences of different tillage meth-ods and crop residues incorporation on the yield of spring maize and physical and chemical properties of soil. The results showed that no matter under what kind of way of crop residues incorporation,the yield of maize with crop res-idues incorporation was higher than that of without. It was best to improve the physical properties of soil,the con-tents of soil nutrient and organic matter under crop residues incorporation every year,the increasing rang of maize yield was highest of all. The physical and chemical properties of soil under crop residues incorporation with urea and crop residues incorporation once every two years were not better than that of without crop residues incorporation. Compared with the tillage method of normal plowing,it can decrease the soil bulk density remarkable in deep soil layer,increase soil porosity,field capacity,soil organic matter content,N,P and K content in the soil,the yield of spring maize under the tillage methods of subsoiling and subsoiling with mixing the soil in different layer. Subsoiling with mixing the soil in different layer can get more good effects on improving soil physical and chemical properties and maize yield than subsoiling in addition,the effects would be best with crop residues incorporation every year.%通过进行2年的田间小区定位试验,研究了不同耕作措施及秸秆还田方式对春玉米产量及土壤理化性状的影响。结果表明:各种秸秆还田方式均可显著提高玉米产量;秸秆连年还田方式最有利于改善土壤的物理性质、提高土壤养分和有机质含量,玉米增产幅度最大;秸秆连年还田配施尿素处理及秸秆隔年还田处理在改善土壤理化性质方面没有表现出明显的优势。深翻、深松耕作方式与普通旋耕相比,可显著降低深层土壤容重,提高土壤孔隙度及土壤田间持水量,增

  4. 秸秆焚烧影响南京空气质量的成因探讨%The origin of crop residue burning impact on air quality of Nanjing

    Institute of Scientific and Technical Information of China (English)

    尹聪; 朱彬; 曹云昌; 苏继锋; 王晓英; 王洪

    2011-01-01

    综合利用卫星遥感的火点和云覆盖信息,结合气团后向轨迹分析,探讨了由秸秆焚烧造成的空气污染物的区域尺度输送和本地源对城市空气量质的影响.