WorldWideScience

Sample records for nitrate-enhanced leachate recirculation

  1. Influence of leachate recirculation on aerobic and anaerobic decomposition of solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Bilgili, M. Sinan [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: ahmetd@yildiz.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)]. E-mail: bozkaya@yildiz.edu.tr

    2007-05-08

    In this study, the effect of leachate recirculation on aerobic and anaerobic degradation of municipal solid wastes is determined by four laboratory-scale landfill reactors. The options studied and compared with the traditional anaerobic landfill are: leachate recirculation, landfill aeration, and aeration with leachate recirculation. Leachate quality is regularly monitored by the means of pH, alkalinity, total dissolved solids, conductivity, oxidation-reduction potential, chloride, chemical oxygen demand, ammonia, and total Kjeldahl nitrogen, in addition to generated leachate quantity. Aerobic leachate recirculated landfill appears to be the most effective option in the removal of organic matter and ammonia. The main difference between aerobic recirculated and non-recirculated landfill options is determined at leachate quantity. Recirculation is more effective on anaerobic degradation of solid waste than aerobic degradation. Further studies are going on to determine the optimum operational conditions for aeration and leachate recirculation rates, also with the operational costs of aeration and recirculation.

  2. The influence of preliminary aerobic treatment on the efficacy of waste stabilisation under leachate recirculation conditions

    Directory of Open Access Journals (Sweden)

    Monika Suchowska-Kisielewicz

    2014-12-01

    Full Text Available This article presents the changes in the chemical composition of leachate and the concentrations and quantity of methane production in each individual decomposition phases, determined for untreated and after aerobic treatment of waste stabilised in anaerobic reactors with and without leachate recirculation. The research results demonstrate that leachate recirculation intensifies the decomposition of both aerobically treated and untreated waste. The methane production in the reactor with untreated, stabilised waste with recirculation was 28% higher; and in the reactor with aerobically treated waste, the methane production was 24% higher than in the reactors without recirculation. An important finding of the study is that aerobic treatment of waste prior to landfilling effectively reduces the quantity of pollutant emissions in leachate and biogas from waste and increases the availability for methane micro-organisms of organic substrates from difficult-to-decompose organic substances.

  3. Mineral and organic compounds in leachate from landfill with concentrate recirculation.

    Science.gov (United States)

    Talalaj, Izabela Anna

    2015-02-01

    The effect of a reverse osmosis concentrate recirculation on the mineral and organic compounds in a landfill leachate was investigated. Investigated was the quality of a leachate from two landfills operated for different periods (a 20-year-old Cell A and a 1-year-old Cell B), where the concentrate was recirculated. Examined were general parameters (conductivity, pH), organic compounds (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic nitrogen, BOD/COD), and inorganic compounds (nitrogen ammonia, sulfite, sulfate, cyanide, boron, chloride, ferrous, zinc, chrome, copper). The findings from the first year of investigation showed that over the initial period of recirculation, the concentration of organic compounds (BOD, COD) increased, but after 6 months their values stabilized. It indicates that the concentrate recirculation accelerated organic decomposition, especially in the new landfill Cell. The analysis of inorganic parameters showed that recirculation landfills produce a leachate with a higher concentration of N-NH4, and Cl(-). In case of the old landfill Cell, an increase in B and Fe was also noticeable. These compounds are cyclically washed out from a waste dump and require an additional pretreatment in order to exclude them from recirculation cycle. The increased concentration of Cu, Zn, and Fe was noticed during the initial months of recirculation and in the season of intense atmospheric precipitation in the leachate from both Cells. Higher values of electro conductivity, Cl(-), N-NH4 (+), B, and Fe in the leachate from the old field indicate that the attenuation capacity of this landfill is close to exhaustion.

  4. Geophysical monitoring of recirculation of leachate on landfill sites in the Netherlands

    NARCIS (Netherlands)

    Kruiver, P.P.; Westerhoff, R.S.; Noorlandt, R.P.; Hoekstra, N.N.; Woelders, H.; Vossen, W.J. van

    2009-01-01

    Geophysical investigations were carried out on two modern landfill sites in the Netherlands. The objective of the geo-electrical and EM31 measurements was to reveal the effect of recirculation of leachate on homogenising moisture content in the waste to stimulate the process of attenuation. At Vlagh

  5. Enhancing biogas production from anaerobic biodegradation of the organic fraction of municipal solid waste through leachate blending and recirculation.

    Science.gov (United States)

    Nair, Arjun; Sartaj, Majid; Kennedy, Kevin; Coelho, Nuno M G

    2014-10-01

    Leachate recirculation has a profound advantage on biodegradation of the organic fraction of municipal solid waste in landfills. Mature leachate from older sections of landfills (>10 years) and young leachate were blended and added to organic fraction of municipal solid waste in a series of biomethane potential assay experiments with different mixing ratios of mature and young leachate and their effect on biogas production was monitored. The improvement in biogas production was in the range of 19%-41% depending on the ratio of mixing old and new leachate. The results are conclusive that the biogas generation could be improved by blending the old and new leachate in a bioreactor landfill system as compared with a conventional system employed in bioreactor landfills today for recirculating the same age leachate.

  6. Removal of Pollutants of Landfill Leachate by Recirculation

    Institute of Scientific and Technical Information of China (English)

    LI Ye; WANG Lina; ZHENG Shizhong

    2008-01-01

    S After leached from municipal solid waste landfill was treated by recirculation, the concentration of pollutants decreases greatly, and the moisture content of the solid waste in landfill site was increased and waste stabilization rate was accelerated. Compared with traditional treatment methods, this method offers more important practical values, including short investment, enhanced treatment efficiency and facilitated operation and management. The experimental results indicated that a 99.9% removel of ammonia nitrogen and an 80.5% removal of COD were obtained, when hydraulic power surface load is 15.92 L/m2·d, and organic surface load is 25.54 g/m2·d.

  7. Temporal and spatial pore water pressure distribution surrounding a vertical landfill leachate recirculation well.

    Science.gov (United States)

    Kadambala, Ravi; Townsend, Timothy G; Jain, Pradeep; Singh, Karamjit

    2011-05-01

    Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

  8. Environmental impact assessment of leachate recirculation in landfill of municipal solid waste by comparing with evaporation and discharge (EASEWASTE).

    Science.gov (United States)

    Xing, Wei; Lu, Wenjing; Zhao, Yan; Zhang, Xu; Deng, Wenjing; Christensen, Thomas H

    2013-02-01

    In some arid regions where landfill produces minimal amount of leachate, leachate recirculation is suggested as a cost-effective option. However, its long-term impacts to environment remain disputed. For the purpose of revealing the environmental impacts of leachate recirculation in landfill, four scenarios were modeled using EASEWASTE, comparing the strategies of leachate recirculation (with or without gas management), evaporation and discharge. In the current situation (Scenario A), a total of 280 t of waste was generated and then transported to a conventional landfill for disposal. A number of contaminants derived from waste can be stored in the landfill for long periods, with 11.69 person equivalent (PE) for stored ecotoxicity in water and 29.62 PE for stored ecotoxicity in soil, considered as potential risks of releasing to the environment someday. Meanwhile, impacts to ecotoxicity and human toxicity in surface water, and those to groundwater, present relatively low levels. In Scenario B, leachate evaporation in a collecting pool has minimal impacts on surface water. However, this strategy significantly impacts groundwater (1055.16 PE) because of the potential infiltration of leachate, with major contaminants of As, ammonia, and Cd. A number of ions, such as Cl(-), Mg(2+), and Ca(2+), may also contaminate groundwater. In Scenario C, the direct discharge of leachate to surface water may result in acidification (2.71 PE) and nutrient enrichment (2.88 PE), primarily attributed to soluble ammonia in leachate and the depositional ammonia from biogas. Moreover, the direct discharge of leachate may also result in ecotoxicity and human toxicity via water contaminated by heavy metals in leachate, with 3.96 PE and 11.64 PE respectively. The results also show that landfill gas is the main contributor to global warming and photochemical ozone formation due to methane emission. In Scenario D, landfill gas flaring was thus be modeled and proven to be efficient for reducing

  9. Effect of inoculum addition modes and leachate recirculation on anaerobic digestion of solid cattle manure in an accumulation system

    NARCIS (Netherlands)

    El-Mashad, H.M.; Loon, van W.K.P.; Zeeman, G.; Bot, G.P.A.; Lettinga, G.

    2006-01-01

    The effect of both leachate recirculation (at 40 and 50 °C) and the mode of inoculum addition (at 50 °C) on the performance of a non-mixed accumulation (i.e. fed batch) system treating solid cattle wastes was investigated, using laboratory scale reactors at a filling time of 60 days. A relatively hi

  10. The effects of leachate recirculation with supplemental water addition on methane production and waste decomposition in a simulated tropical landfill.

    Science.gov (United States)

    Sanphoti, N; Towprayoon, S; Chaiprasert, P; Nopharatana, A

    2006-10-01

    In order to increase methane production efficiency, leachate recirculation is applied in landfills to increase moisture content and circulate organic matter back into the landfill cell. In the case of tropical landfills, where high temperature and evaporation occurs, leachate recirculation may not be enough to maintain the moisture content, therefore supplemental water addition into the cell is an option that could help stabilize moisture levels as well as stimulate biological activity. The objectives of this study were to determine the effects of leachate recirculation and supplemental water addition on municipal solid waste decomposition and methane production in three anaerobic digestion reactors. Anaerobic digestion with leachate recirculation and supplemental water addition showed the highest performance in terms of cumulative methane production and the stabilization period time required. It produced an accumulated methane production of 54.87 l/kg dry weight of MSW at an average rate of 0.58 l/kg dry weight/d and reached the stabilization phase on day 180. The leachate recirculation reactor provided 17.04 l/kg dry weight at a rate of 0.14l/kg dry weight/d and reached the stabilization phase on day 290. The control reactor provided 9.02 l/kg dry weight at a rate of 0.10 l/kg dry weight/d, and reached the stabilization phase on day 270. Increasing the organic loading rate (OLR) after the waste had reached the stabilization phase made it possible to increase the methane content of the gas, the methane production rate, and the COD removal. Comparison of the reactors' efficiencies at maximum OLR (5 kgCOD/m(3)/d) in terms of the methane production rate showed that the reactor using leachate recirculation with supplemental water addition still gave the highest performance (1.56 l/kg dry weight/d), whereas the leachate recirculation reactor and the control reactor provided 0.69 l/kg dry weight/d and 0.43 l/kg dry weight/d, respectively. However, when considering

  11. Environmental impact assessment of leachate recirculation in landfill of municipal solid waste by comparing with evaporation and discharge (EASEWASTE)

    DEFF Research Database (Denmark)

    Xing, Wei; Lu, Wenjing; Zhao, Yan

    2013-01-01

    in leachate and the depositional ammonia from biogas. Moreover, the direct discharge of leachate may also result in ecotoxicity and human toxicity via water contaminated by heavy metals in leachate, with 3.96 PE and 11.64 PE respectively. The results also show that landfill gas is the main contributor...... of contaminants derived from waste can be stored in the landfill for long periods, with 11.69 person equivalent (PE) for stored ecotoxicity in water and 29.62 PE for stored ecotoxicity in soil, considered as potential risks of releasing to the environment someday. Meanwhile, impacts to ecotoxicity and human...... scenarios were modeled using EASEWASTE, comparing the strategies of leachate recirculation (with or without gas management), evaporation and discharge. In the current situation (Scenario A), a total of 280t of waste was generated and then transported to a conventional landfill for disposal. A number...

  12. Effect of increasing salinity on biogas production in waste landfills with leachate recirculation: A lab-scale model study.

    Science.gov (United States)

    Ogata, Yuka; Ishigaki, Tomonori; Nakagawa, Mikako; Yamada, Masato

    2016-06-01

    The effects of salinity on anaerobic waste degradation and microbial communities were investigated, in order to propose an appropriate leachate recirculation process in a waste landfill in a tropical region. A salt concentration of 21 mS cm(-1) of electrical conductivity (EC) did not affect waste degradation, but a salt concentration of 35 mS cm(-1) of EC inhibited CH4 generation. A higher salt concentration of 80 mS cm(-1) of EC inhibited not only CH4 and CO2 generation, but also degradation of organic compounds. The bacterial and archaeal community compositions were affected by high salinity. High salinity can exert selective pressure on bacterial communities, resulting in a change in bacterial community structure. Ammonium caused strong, dominant inhibition of biogas production in the salt concentration range of this study. Quality control, especially of ammonium levels, will be essential for the promotion of waste biodegradation in landfills with leachate recirculation.

  13. Hydraulic retention time impact of treated recirculated leachate on the hydrolytic kinetic rate of coffee pulp in an acidogenic reactor.

    Science.gov (United States)

    Houbron, E; González-López, G I; Cano-Lozano, V; Rustrían, E

    2008-01-01

    This study attempted to investigate the impact of HRT of treated leachate recirculation on hydrolysis solubilization rate of coffee pulp in an acidogenic reactor. Coffee pulp presents more than 70% of organic matter and around of 30% of lignin and cellulose. Five lab scale reactors of 20 litres were used. Each reactor was fed with 5 kg of fresh coffee pulp and anaerobic sludge was used as inoculate. HRT of 0.5, 1, 3 and 10 days were applied. Each experiment shows that Total, Soluble and VFA COD appear rapidly in the removed leachate. HRT have a great impact on hydrolytic rate with an optimal value of 32,000 mg x L(-1) x d(-1).Low HRT increases hydrolysis rate and in consequence reduces duration of the hydrolytic phase. Also composition and concentration of VFA are influenced by HRT. Low ones favour acetic acid production and high ones permit the production of butyric. Low HRT generates leachate more easily fermentable. Efficiency of solubilization and acidification are independent of the HRT and present average values of 78% and 65% respectively. By batch feeding solid and continuous recirculation of treated leachate, HRT and SRT could be dissociated, where solid had a very high retention without problems of load, mixing and inhibition, and liquid could be recirculated with a very high rate. Under these low HRT condition, the first reactor of a two stage anaerobic system could reduces the hydrolysis duration of organic solid waste like coffee pulp and generate an optimal leachate for the methanization process. Copyright IWA Publishing 2008.

  14. Transport behavior of surrogate biological warfare agents in a simulated landfill: Effect of leachate recirculation and water infiltration

    KAUST Repository

    Saikaly, Pascal

    2010-11-15

    An understanding of the transport behavior of biological warfare (BW) agents in landfills is required to evaluate the suitability of landfills for the disposal of building decontamination residue (BDR) following a bioterrorist attack on a building. Surrogate BW agents, Bacillus atrophaeus spores and Serratia marcescens, were spiked into simulated landfill reactors that were filled with synthetic building debris (SBD) and operated for 4 months with leachate recirculation or water infiltration. Quantitative polymerase chain reaction (Q-PCR) was used to monitor surrogate transport. In the leachate recirculation reactors, <10% of spiked surrogates were eluted in leachate over 4 months. In contrast, 45% and 31% of spiked S. marcescens and B. atrophaeus spores were eluted in leachate in the water infiltration reactors. At the termination of the experiment, the number of retained cells and spores in SBD was measured over the depth of the reactor. Less than 3% of the total spiked S. marcescens cells and no B. atrophaeus spores were detected in SBD. These results suggest that significant fractions of the spiked surrogates were strongly attached to SBD. © 2010 American Chemical Society.

  15. Biogas recirculation for simultaneous calcium removal and biogas purification within an expanded granular sludge bed system treating leachate.

    Science.gov (United States)

    Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng

    2014-12-01

    Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content.

  16. Hydro-mechanical behavior of municipal solid waste subject to leachate recirculation in a large-scale compression reactor cell.

    Science.gov (United States)

    Olivier, Franck; Gourc, Jean-Pierre

    2007-01-01

    The paper presents the results of a laboratory experiment on Municipal Solid Waste (MSW) subjected to one-dimensional compression in a 1 m3 instrumented cell. The focus was on the hydro-mechanical behavior of the material under conditions of confinement and leachate percolation that replicate those found in real-scale landfills. The operation of the apparatus is detailed together with the testing methodology and the monitoring program. Two samples of waste were tested: the first extended over a period of 10 months ('Control Test') and the second for 22 months ('Enhanced Test' with leachate recirculation). Consolidation data is reported with regard to both short-term (stress-dependent) and long-term (time-dependent) settlements. A discussion follows based on the derived values of primary and secondary compression ratios. Correlations between compression parameters and the biodegradation process are presented. In particular, results clearly highlight the effect of leachate recirculation on waste settlement: 24% secondary deformation reached after slightly less than 2 years (equivalent to a 5-fold increase in compressibility) and 17.9% loss of dry matter. Comparisons are proposed considering the results derived from the few monitoring programs conducted on experimental bioreactors worldwide. Finally, the hydraulic characterization of waste is discussed with regard to the evaluation of effective porosity and permeability.

  17. Experimental simulation and fuzzy modelling of landfill biogas production from low-biodegradable MBT waste under leachate recirculation.

    Science.gov (United States)

    Di Addario, Martina; Ruggeri, Bernardo

    2017-08-10

    In the perspective of a sustainable waste management, biodegradable waste destined to landfilling should be reduced. This work aims to study a combination of waste pretreatments and leachate recirculation. A lab-scale experiment and fuzzy-modelling were chosen to predict cumulative methane production from low-biodegradable waste (LBW) under leachate recirculation. Thanks to moisture increase, the degradation of LBW was reactivated and the cumulative methane production reached 28 NL CH4 kg(-1) after 442 days. The organic fraction was stabilized with a final chemical oxygen demand (COD) of 81 mg L(-1). Fuzzy model was proposed as an alternative to the common deterministic models, affected by high uncertainties. Eleven inputs (pH, Redox potential, COD, volatile fatty acids, ammonium content, age, temperature, moisture content, organic fraction concentration, particle size and recirculation flow rate) were identified as antecedent, and two outputs, or consequents, were chosen: methane production rate and methane fraction in biogas. Antecedents and consequents were linked by 84 IF-THEN rules in a linguistic form. The model was also tested on six literature studies chosen to test different operational conditions and waste qualities. The model outputs fitted the experimental data reasonably well, confirming the potential use of fuzzy macro-approach to model sustainable landfilling.

  18. Effect of a solar Fered-Fenton system using a recirculation reactor on biologically treated landfill leachate.

    Science.gov (United States)

    Ye, Zhihong; Zhang, Hui; Yang, Lin; Wu, Luxue; Qian, Yue; Geng, Jinyao; Chen, Mengmeng

    2016-12-05

    The effects of electrochemical oxidation (EO), Fered-Fenton and solar Fered-Fenton processes using a recirculation flow system containing an electrochemical cell and a solar photo-reactor on biochemically treated landfill leachate were investigated. The most successful method was solar Fered-Fenton which achieved 66.5% COD removal after 120min treatment utilizing the optimum operating conditions of 47mM H2O2, 0.29mM Fe(2+), pH0 of 3.0 and a current density of 60mA/cm(2). The generation of hydroxyl radicals (OH) are mainly from Fered-Fenton process, which is enhanced by the introduction of renewable solar energy. Moreover, Fe(2+)/chlorine and UV/chlorine processes taking place in this system also result in additional production of OH due to the relatively high concentration of chloride ions contained in the leachate. The energy consumption was 74.5kWh/kg COD and the current efficiency was 36.4% for 2h treatment. In addition, the molecular weight (MW) distribution analysis and PARAFAC analysis of excitation emission matrix (EEM) fluorescence spectroscopy for different leachate samples indicated that the organics in the leachate were significantly degraded into either small molecular weight species or inorganics.

  19. Effect of increasing salinity on biogas production in waste landfills with leachate recirculation: A lab-scale model study

    Directory of Open Access Journals (Sweden)

    Yuka Ogata

    2016-06-01

    Full Text Available The effects of salinity on anaerobic waste degradation and microbial communities were investigated, in order to propose an appropriate leachate recirculation process in a waste landfill in a tropical region. A salt concentration of 21 mS cm−1 of electrical conductivity (EC did not affect waste degradation, but a salt concentration of 35 mS cm−1 of EC inhibited CH4 generation. A higher salt concentration of 80 mS cm−1 of EC inhibited not only CH4 and CO2 generation, but also degradation of organic compounds. The bacterial and archaeal community compositions were affected by high salinity. High salinity can exert selective pressure on bacterial communities, resulting in a change in bacterial community structure. Ammonium caused strong, dominant inhibition of biogas production in the salt concentration range of this study. Quality control, especially of ammonium levels, will be essential for the promotion of waste biodegradation in landfills with leachate recirculation.

  20. Effect of hydraulic retention time and sludge recirculation on greenhouse gas emission and related microbial communities in two-stage membrane bioreactor treating solid waste leachate.

    Science.gov (United States)

    Nuansawan, Nararatchporn; Boonnorat, Jarungwit; Chiemchaisri, Wilai; Chiemchaisri, Chart

    2016-06-01

    Methane (CH4) and nitrous oxide (N2O) emissions and responsible microorganisms during the treatment of municipal solid waste leachate in two-stage membrane bioreactor (MBR) was investigated. The MBR system, consisting of anaerobic and aerobic stages, were operated at hydraulic retention time (HRT) of 5 and 2.5days in each reactor under the presence and absence of sludge recirculation. Organic and nitrogen removals were more than 80% under all operating conditions during which CH4 emission were found highest under no sludge recirculation condition at HRT of 5days. An increase in hydraulic loading resulted in a reduction in CH4 emission from anaerobic reactor but an increase from the aerobic reactor. N2O emission rates were found relatively constant from anaerobic and aerobic reactors under different operating conditions. Diversity of CH4 and N2O producing microorganisms were found decreasing when hydraulic loading rate to the reactors was increased.

  1. USE OF RECIRCULATION TECHNIQUE OF CONCENTRATED LEACHATE PRODUCED BY LEACHATE REVERSE-OSMOSIS%渗滤液的反渗透浓缩液回灌技术应用

    Institute of Scientific and Technical Information of China (English)

    宋延冬; 左俊芳; 朱正贤

    2012-01-01

    The paper takes landfills in Yichang,Ningguo and Mengcheng for example,it was introduced a process of disc tube reverse osmosis(DTRO)——concentrated leachate recirculation.The result indicated that the way of recirculation should be based on the geographical features of landfill and owners' demand.Valley landfills can use the way of stone cage recirculation that is built simply at low-cost.On the other hand,the way of two-biological filter bed which is more effective can also be used although more costly.Plain landfills should use two-layer biological filter bed,short flow may be caused if use the way of stone cage recirculation.Conductance will not be influenced obviously due to recirculation,and the normal operation of RO system won't be affected.%以宜昌、宁国、蒙城垃圾填埋场为例,介绍了碟管式反渗透(DTRO)——浓缩液回灌工艺,研究发现:浓缩液回灌方式应根据垃圾填埋场的地理特征和业主的具体要求来确定。山谷型填埋场可以采用石笼回灌法,施工简单,成本较低,另外也可采用两层生物滤化床方式,成本稍高,但效果较好;平原型填埋场宜采用两层生物滤化床方式,而采用石笼回灌法容易出现短流现象。浓缩液回灌对渗滤液电导率无明显影响,不会影响后续反渗透系统的正常运行。

  2. Determination of acceleration and stabilization indicators for buried municipal wastes. Study of leachates recirculation impact on waste columns; Determination d'indicateurs d'acceleration et de stabilisation de dechets menagers enfouis. Etude de l'impact de la recirculation de lixiviats sur colonnes de dechets

    Energy Technology Data Exchange (ETDEWEB)

    Francois, V.

    2004-05-15

    The main goal of this research work was to study the stabilisation processes of municipal solid waste (MSW). Representative parameters, which are required to evaluate the stabilization state of wastes, were applied to study the acceleration of the degradation processes in lab-scale landfill anaerobic bioreactors operated with leachate recirculation. The characterisation of the wastes solid phase (i.e., volatile solids, organic carbon, fines, paper-cardboard and degraded component contents) is necessary to assess its degradation state. However, additional parameters are required such as the characterisation of water extracted from the waste (i.e., Chemical Oxygen Content (COD), Dissolved Oxygen Content (DOC) and ions content) and biogas composition (methane potential). Those parameters are nevertheless complementary to conclude on its polluting feature. The analysis of more specific indicators such as the organic macromolecules content in leachates and the evaluation of the metal contamination level in solid waste and its potential remobilization was showed to be consistent for the evaluation of waste stabilisation state. The composition of leachates used during recirculation influences greatly the waste leaching behaviour. For instance, the recirculation of a stabilised leachate containing organic macromolecules can increase the release of pollutants (organics and minerals) if contacted with young waste or on the other hand the release of pollutant is reduced when the leachate composition is similar to the organic species, which are expected to be released by the wastes. Due to the experimental limits of the leaching tests, several lab-scale landfill anaerobic bioreactors containing different wastes types (height of 1 m and mass of waste varying from 28 kg to 65 kg) were operated to study the effects of recirculation on the waste degradation at flow rate of 540 mL per day. The speed-up of waste degradation was clearly established from global parameters measured on

  3. Influence of the civil construction debris layer in heavy metals removal of the leachate submitted to recirculation in landfill

    Directory of Open Access Journals (Sweden)

    Maike Rossmann

    2010-08-01

    Full Text Available Little is known about the ability of stabilized organic matter (old MSW and construction waste (RCC to retain heavy metals from leachate generated in landfills. The objective of this study was to assess the potential of MSW to remove old heavy metals in MSW leachate produced by freshly collected, and the effect of RCC in the concentration of heavy metals in effluents from MSW old. In three columns (CR, put a layer of RCC and then MSW old and, on the other three (SR, only MSW old. Analyzed in the leachate and effluent pH, EC, BOD and metals Zn, Cd, Cu and Pb. There were similar and efficient removal of BOD and heavy metals in both treatments. The presence of the layer of RCC was considered important to the overall improvement in effluent quality, but did not influence the concentration of metals in the effluent. The order of retention of metals in the columns was: Cu ~ Pb> Cd> Zn. With the exception of Cd and Zn, all other variables assessed in the effluent were below the maximum standards set in DN 01.08 COPAM / CERH for release effluent into water bodies.

  4. Nitrous oxides reduction pathways induced during nitrified leachate recirculation in bioreactor landfill; Voies de reduction des oxydes d'azote lors de leur injection dans un massif de dechets menagers et assimiles: contribution a l'etude de la recirculation de lixiviat nitrifie dans une installation de stockage de dechets menagers et assimiles bioactive

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.

    2005-12-15

    Nitrified leachate recirculation in bioreactor landfill has been proposed to avoid ammonium accumulation. We worked on the identification of nitrous oxides reduction pathways induced when nitrified leachate is recirculated during waste degradation. Batch reactors (1.1 liter, 40 g of reconstituted Municipal Solid Waste, MSW) were operated at 35 deg C and saturated with leachate. Injections of 250 mg N-NO{sub x}.10{sup -1} were performed during different phases of waste biodegradation. Nitrate reduction during acido-genic and active methanogenic phases, with an easily available carbon source in leachate, was mainly attributed to heterotrophic denitrification. However, H{sub 2}S concentration up to 0.7 % in the biogas (corresponding to 0.5 mmol of free H{sub 2}S per liter of leachate) led to prevalent DNRA (Dissimilatory Nitrate Reduction to Ammonium) over denitrification. This reaction hindered the release of nitrogen outside of the system. This observation was confirmed with experiments performed with {sup 15}N enriched nitrate. During late methanogenic phase, without any available carbon source in leachate, nitrate was reduced by autotrophic denitrification with sulfide as an electron donor. No free metal was detected in the leachate. N{sub 2}O transient accumulation was detected during both DNRA and autotrophic denitrification. A second set of experiments was conducted in a MSW pilot scale column (0.2 m{sup 3}, 80 kg of reconstituted waste) in methanogenic phase. 113 % and 203 % of nitrate were converted into N{sub 2} when a synthetic KNO{sub 3} solution (280 mg N.day{sup -1} during 77 days) or nitrified leachate (61 mg N.day{sup -1} during 54 days) were respectively injected into the system. The downward movement of a denitrification front passing through the waste mass was followed using 3 redox probes inserted at different levels of the pilot. Even if N{sub 2}O was never detected, a small production of this gas could not be totally excluded. It was established

  5. 生物反应器填埋场中水平沟回灌渗滤液非饱和-饱和渗流分析%Unsaturated-saturated seepage analysis for leachate recirculation using horizontal trenches in bioreactor landfills

    Institute of Scientific and Technical Information of China (English)

    冯世进; 张旭

    2013-01-01

    The horizontal trench is one of the main methods which are available to recirculate leachates.To study the unsaturated-saturated seepage laws during leachate recirculation process,different flow control equations are used for the saturated/unsaturated zones in bioreactor landfills.The saturated Richards' equation is adopted as the flow governing equation in the saturated area of the waste mass.For the unsaturated area of the waste mass,based on the law of conservation of mass,the modified Darcy's law and the Elagroudy's settlement model,a new flow governing equation considering solid waste settlement is developed.Based on the two-dimensional saturated/unsaturated model which has been developed considering solid waste settlement,the migration laws of recirculated leachates are studied.The simulated results indicate that the various parameters (i.e.,settlement of MSW,pressure head,initial void ratio,etc.) have effects on the zone of impact,pressure head,water content of MSW and recirculation leachate volume per m of trench length.The design method of horizontal trenches is proposed for the bioreactor landfills.%水平沟回灌是生物反应器填埋场中渗滤液回灌的主要模式之一,为研究水平沟回灌时生物反应器填埋场中渗滤液的非饱和-饱和运移规律,垃圾体的饱和与非饱和区域采用不同水流控制方程,饱和区域的水流控制方程采用饱和Richards方程,对垃圾体非饱和区域,由质量守恒原理,以修正的Darcy定理为基础,结合Elagroudy等提出的垃圾体沉降模型,建立了考虑垃圾体沉降的非饱和渗滤液运移控制方程.基于建立的考虑沉降特性的二维非饱和-饱和水平沟回灌计算模型,研究了水平沟回灌时渗滤液在生物反应器填埋场中的运移规律,提出水平沟回灌系统的设计方法.

  6. The Study on the Recirculation System for Landfill Leachate in Northwest of China%西北卫生填埋场渗滤液回灌系统研究

    Institute of Scientific and Technical Information of China (English)

    徐燕; 苟剑锋; 曾正中; 吴凯; 张贺飞

    2011-01-01

    回灌技术是一种简单、低廉的渗滤液处理技术,可有效降低渗滤液中COD和氨氮的含量,加速填埋场内垃圾的降解,提高产甲烷速率和甲烷的产量,增大填埋场的沉降速率和总沉降幅度,缩短填埋场的维护期.回灌技术能够适应渗滤液水质水量的复杂变化,在我国西北地区有非常广阔的应用前景.同时,由于该技术在我国利用过程中尚缺乏成熟的工艺设计和运行经验,所以还有待进一步研究和实践.%Recirculation is a simple and cheap way for dealing with the landfill leachate. It can effectively reduce the contents of COD and ammonia nitrogen in leachate. It also can accelerate the degradation of landfill waste,improve methane production rate and methane production. It increase the rate of sedimentation and the extent of sedimentation,shorten the maintenance period of landfill. Recirculation is suit for the changes of quality and quantity of leachate and can be widely used in Northwest of China. But there was still lack of maturity in the use of process design and operation experience, so it needed the further research and practice.

  7. RECIRCULATING ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.; GARREN,A.A.; JOHNSTONE,C.

    2000-04-07

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous.

  8. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: I. LEACHATE HYDROLOGY AND WASTE SETTLEMENT

    Science.gov (United States)

    An assessment of state-of-the-practice at five full-scale North American landfills operating as bioreactors is presented in this two-paper set. This paper focuses on effectiveness of liners and leachate collection systems, leachate generation rates, leachate recirculation practi...

  9. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: I. LEACHATE HYDROLOGY AND WASTE SETTLEMENT

    Science.gov (United States)

    An assessment of state-of-the-practice at five full-scale North American landfills operating as bioreactors is presented in this two-paper set. This paper focuses on effectiveness of liners and leachate collection systems, leachate generation rates, leachate recirculation practi...

  10. Quality and Quantity of Leachate in Aerobic Pilot-Scale Landfills

    Science.gov (United States)

    Bilgili, Memmet Sinan; Demir, Ahmet; Özkaya, Bestamin

    2006-08-01

    In this study, two pilot-scale aerobic landfill reactors with (A1) and without (A2) leachate recirculation are used to obtain detailed information on the quantity and quality of leachate in aerobic landfills. The observed parameters of leachate quality are pH, chloride (Cl-), chemical oxygen demand (COD), biological oxygen demand (BOD), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH3-N), and nitrate (NO3 --N). pH values of the leachate increased to 7 after 50 days in reactor A1 and after 70 days in reactor A2. Cl- concentrations increased rapidly to 6100 (A1) and 6900 (A2) mg/L after 80 days, from initial values of 3000 and 2800 mg/L, respectively. COD and BOD values decreased rapidly in the A1 landfill reactor, indicating the rapid oxidation of organic matter. The BOD/COD ratio indicates that leachate recirculation slightly increases the degradation of solid waste in aerobic landfills. NH3-N concentrations decreased as a result of the nitrification process. Denitrification occurred in parts of the reactors as a result of intermittent aeration; this process causes a decrease in NO3 - concentrations. There is a marked difference between the A1 and A2 reactors in terms of leachate quantity. Recirculated leachate made up 53.3% of the leachate generated from the A1 reactor during the experiment, while leachate quantity decreased by 47.3% with recirculation when compared with the aerobic dry landfill reactor.

  11. COD fractions of leachate from aerobic and anaerobic pilot scale landfill reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bilgili, M. Sinan [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ahmetd@yildiz.edu.tr; Akkaya, Ebru [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ekoca@yildiz.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: bozkaya@yildiz.edu.tr

    2008-10-01

    One of the most important problems with designing and maintaining a landfill is managing leachate that generated when water passes through the waste. In this study, leachate samples taken from aerobic and anaerobic landfill reactors operated with and without leachate recirculation are investigated in terms of biodegradable and non-biodegradable fractions of COD. The operation time is 600 days for anaerobic reactors and 250 days for aerobic reactors. Results of this study show that while the values of soluble inert COD to total COD in the leachate of aerobic landfill with leachate recirculation and aerobic dry reactors are determined around 40%, this rate was found around 30% in the leachate of anaerobic landfill with leachate recirculation and traditional landfill reactors. The reason for this difference is that the aerobic reactors generated much more microbial products. Because of this condition, it can be concluded that total inert COD/total COD ratios of the aerobic reactors were 60%, whereas those of anaerobic reactors were 50%. This study is important for modeling, design, and operation of landfill leachate treatment systems and determination of discharge limits.

  12. Different leachate phytotreatment systems using sunflowers.

    Science.gov (United States)

    Garbo, Francesco; Lavagnolo, Maria Cristina; Malagoli, Mario; Schiavon, Michela; Cossu, Raffaello

    2017-01-01

    The use of energy crops in the treatment of wastewaters is of increasing interest, particularly in view of the widespread scarcity of water in many countries and the possibility of obtaining renewable fuels of vegetable origin. The aim of this study was to evaluate the feasibility of landfill leachate phytotreatment using sunflowers, particularly as seeds from this crop are suitable for use in biodiesel production. Two different irrigation systems were tested: vertical flow and horizontal subsurface flow, with or without effluent recirculation. Plants were grown in 130L rectangular tanks placed in a special climatic chamber. Leachate irrigated units were submitted to increasing nitrogen concentrations up to 372mgN/L. Leachate was successfully tested as an alternative fertilizer for plants and was not found to inhibit biomass development. The experiment revealed good removal efficiencies for COD (η>50%) up until flowering, while phosphorous removal invariably exceeded 60%. Nitrogen removal rates decreased over time in all experimental units, particularly in vertical flow tanks. In general, horizontal flow units showed the best performances in terms of contaminant removal capacity; the effluent recirculation procedure did not improve performance. Significant evapo-transpiration was observed, particularly in vertical flow units, promoting removal of up to 80% of the inlet irrigation volume.

  13. Impact assessment of concentrate recirculation on the landfill gas production

    Directory of Open Access Journals (Sweden)

    Džolev Nikola M.

    2016-01-01

    Full Text Available This paper explores the impact of concentrate recirculation, as a product of leachate treated by reverse osmosis plant, on the production of landfill gas at the real-scale landfill for municipal solid waste. In an effort to come up with results experimental measurements were carried out at the landfill in Bijeljina. All measurements performed, were divided into 3 groups. The aims of two groups of measurement were to determine landfill gas and methane yield from concentrate and leachate in laboratory conditions (1st group and to find out concentrations of oxidizing matters (COD and BOD5 present in leachate and concentrate at different points of treatment as well as its variability over the time (2nd group which could be used to calculate the potential of landfill gas and methane generation from concentrate by recirculation, theoretically. 3rd group of measurements, carried out in parallel, have goal to determine the quality and quantity of the collected landfill gas at wells throughout the landfill. The results of analysis carried out in this experimental research show the clear evidence of concentrate recirculation impact on methane production by increasing the landfill gas flow, as well as its concentration within the landfill gas composition, at the nearby well. Although results indicated relatively high impact of concentrate recirculation on landfill gas production, comparing to its theoretical potential, the influence on the landfill at whole, is negligible, due to relatively low volumes in recirculation with respect to its size and objectively low potential given by organic matter present in concentrate.

  14. Releasing behavior of copper in recirculated bioreactor landfill.

    Science.gov (United States)

    Long, Yu-Yang; Hu, Li-Fang; Jiang, Chen-Jing; Fang, Cheng-Ran; Wang, Feng-Ping; Shen, Dong-Sheng

    2009-04-01

    The purpose of this study was to determine the releasing behavior of copper in municipal solid waste (MSW) in landfill with respect to refuse and leachate as an inseparable system. Two simulated bioreactor landfills, one with leachate recirculation and the other without, were operated in room temperature for 320 days. Copper in refuse showed behaviors of staggered migration and retention, which corresponded with the degradation process of landfill obviously. The significant different amounts of Cu2+ leached out from refuse into leachate of two landfills were 24.74 mg and 118.53 mg after 320 days' operation, respectively. It also reflected the releasing behavior of copper in landfill refuse at different stage accordingly. The results confirmed that the refuse in landfill had high potential of secondary pollution after closure.

  15. Effect of landfill characteristics on leachate organic matter properties and coagulation treatability.

    Science.gov (United States)

    Comstock, Sarah E H; Boyer, Treavor H; Graf, Katherine C; Townsend, Timothy G

    2010-11-01

    This work spans landfill characteristics, leachate organic matter properties, and coagulation chemistry to provide new insights into the physical-chemical treatability of stabilized landfill leachate. Furthermore, leachate organic matter is viewed in terms of dissolved organic matter (DOM) present in the natural environment, and coagulation chemistry is evaluated based on previous leachate and water treatment coagulation studies. Stabilized leachate was collected from four landfills for a total of seven leachate samples, and samples were coagulated using ferric chloride, ferric sulfate, and aluminum sulfate. Landfill characteristics, such as age, leachate recirculation, and cover material, influenced properties of DOM present in the leachate, as measured by specific ultraviolet (UV) absorbance at 254 nm (SUVA254) and fluorescence excitation-emission matrices. The coagulation performance of the metal salts was ferric sulfate>aluminum sulfate>ferric chloride, and DOM removal followed the trend of color>UV254>dissolved organic carbon>chemical oxygen demand (COD). Finally, a strong association was found between increasing SUVA254 and increasing DOM removal for coagulation of both leachate and natural surface water. Thus, SUVA254 is expected to be a better predictor of leachate treatability, in particular DOM removal, than the traditionally used ratio of biochemical oxygen demand to COD. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Ammonia removal from leachate by photochemical process using H2O2

    Directory of Open Access Journals (Sweden)

    Giovani Archanjo Brota

    2010-08-01

    Full Text Available In this work, it was studied the optimization of the photochemical process using H2O2/UV in order to reduce the concentration of ammonia in leachate. It was used landfills leachate previously treated in the development of studies. A photochemical reactor with the capacity of 1.7 liters equipped with refrigeration system and recirculation of leachate was employed in the research. The influence of temperature, the light bulb power, the concentration of H2O2 and treatment time were tested during the study. A removal of 97% of ammonia was observed at 90 min.

  17. Electrochemical treatment of leachates from sanitary landfills

    Directory of Open Access Journals (Sweden)

    ANNABEL FERNANDES

    2013-06-01

    Full Text Available The electrochemical treatment of leachate samples from a Portuguese intermunicipal sanitary landfill was carried out using anodic oxidation. The treatment was performed in a pilot plant that possesses an electrochemical cell, with boron-doped diamond electrodes, working in batch mode with recirculation. The influence of the applied current density and the flow rate on the performance of the electrochemical oxidation was investigated. Current density was decreased by steps, during the degradation, in order to study this effect on the efficiency of the process. For the assays run at equal flow rate and initial current intensity, chemical oxygen demand (COD removal seems to depend mainly on the charge passed and the variation of the current density during the anodic oxidation process can reduce the energetic costs. An increase in the recirculation flow rate leads to an increase in the organic load removal rate and a consequent decrease in the energetic costs, but it decreases the nitrogen removal rate. Also, the bias between dissolved organic carbon and COD removals increases with flow rate, indicating that an increase in recirculation flow rate decreases the mineralization index.

  18. Recirculation of reverse osmosis concentrate in lab-scale anaerobic and aerobic landfill simulation reactors.

    Science.gov (United States)

    Morello, Luca; Cossu, Raffaello; Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina

    2016-10-01

    Leachate treatment is a major issue in the context of landfill management, particularly in view of the consistent changes manifested over time in the quality and quantity of leachate produced, linked to both waste and landfill characteristics, which renders the procedure technically difficult and expensive. Leachate recirculation may afford a series of potential advantages, including improvement of leachate quality, enhancement of gas production, acceleration of biochemical processes, control of moisture content, as well as nutrients and microbe migration within the landfill. Recirculation of the products of leachate treatment, such as reverse osmosis (RO) concentrate, is a less common practice, with widespread controversy relating to its suitability, potential impacts on landfill management and future gaseous and leachable emissions. Scientific literature provides the results of only a few full-scale applications of concentrate recirculation. In some cases, an increase of COD and ammonium nitrogen in leachate was observed, coupled with an increase of salinity; which, additionally, might negatively affect performance of the RO plant itself. In other cases, not only did leachate production not increase significantly but the characteristics of leachate extracted from the well closest to the re-injection point also remained unchanged. This paper presents the results of lab-scale tests conducted in landfill simulation reactors, in which the effects of injection of municipal solid waste (MSW) landfill leachate RO concentrate were evaluated. Six reactors were managed with different weekly concentrate inputs, under both anaerobic and aerobic conditions, with the aim of investigating the short and long-term effects of this practice on landfill emissions. Lab-scale tests resulted in a more reliable identification of compound accumulation and kinetic changes than full-scale applications, further enhancing the development of a mass balance in which gaseous emissions and waste

  19. Beam Injection in Recirculator SALO

    CERN Document Server

    Guk, Ivan S; Dovbnya, Anatoly N; Kononenko, Stanislav; Peev, Fedor; Tarasenko, Alexander; Van der Wiel, Marnix

    2005-01-01

    Possible antetypes of injectors for electron recirculator SALO,* intended for nuclear-physical research, are analyzed. The plan injection of beams in recirculator is offered. Expected parameters of beams are designed.

  20. Energy consumption by forward osmosis treatment of landfill leachate for water recovery.

    Science.gov (United States)

    Iskander, Syeed Md; Zou, Shiqiang; Brazil, Brian; Novak, John T; He, Zhen

    2017-03-22

    Forward osmosis (FO) is an alternative approach for treating landfill leachate with potential advantages of reducing leachate volume and recovering high quality water for direct discharge or reuse. However, energy consumption by FO treatment of leachate has not been examined before. Herein, the operational factors such as recirculation rates and draw concentrations were studied for their effects on the quantified energy consumption by an FO system treating actual leachate collected from two different landfills. It was found that the energy consumption increased with a higher recirculation rate and decreased with a higher draw concentration, and higher water recovery tended to reduce energy consumption. The highest energy consumption was 0.276±0.033kWhm(-3) with the recirculation rate of 110mLmin(-1) and 1-M draw concentration, while the lowest of 0.005±0.000kWhm(-3) was obtained with 30mLmin(-1) recirculation and 3-M draw concentration. The leachate with lower concentrations of the contaminants had a much lower requirement for energy, benefited from its higher water recovery. Osmotic backwashing appeared to be more effective for removing foulants, but precise understanding of membrane fouling and its controlling methods will need a long-term study. The results of this work have implied that FO treatment of leachate could be energy efficient, especially with the use of a suitable draw solute that can be regenerated in an energy efficient way and/or through combination with other treatment technologies that can reduce contaminant concentrations before FO treatment, which warrants further investigation.

  1. 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.

  2. An Interactive Real-time Decision Support System for Leachate Irrigation on Evapotranspiration Landfill Covers

    Science.gov (United States)

    Wang, Y.

    2015-12-01

    Landfill disposal is still the most common and economical practice for municipal solid waste in most countries. However, heavily polluted leachate generated by excess rainwater percolating through the landfill waste is the major drawback of this practice. Evapotranspiration (ET) cover systems are increasingly being used as alternative cover systems to minimize percolation by evapotranspiration. Leachate recirculation is one of the least expensive options for leachate treatment. The combination of ET cover systems and leachate recirculation can be an economical and environment-friendly practice for landfill leachate management. An interactive real-time decision support system is being developed to better manage leachate irrigation using historical and forecasting weather data, and real time soil moisture data. The main frame of this system includes soil water modules, and plant-soil modules. An inverse simulation module is also included to calibrate certain parameters based on observed data when necessary. It would be an objectives-oriented irrigation management tool to minimize landfill operation costs and negative environmental impacts.

  3. Quantification of regional leachate variance from municipal solid waste landfills in China

    DEFF Research Database (Denmark)

    Yang, Na; Damgaard, Anders; Kjeldsen, Peter;

    2015-01-01

    contents. To overcome this problem, a new estimation method was established considering two sources: (1) precipitation infiltrated throughout waste layers, which was simulated with the HELP model, (2) water squeezed out of the waste itself, which was theoretically calculated using actual data of Chinese...... of about 58.2%. In China-NW, accumulated leachate amounts were very low and mainly the result of waste degradation, implying on-site spraying/irrigation or recirculation may be an economic approach to treatment. In China-N, water squeezed out of waste by compaction totaled 22-45% of overall leachate......The quantity of leachate is crucial when assessing pollution emanating from municipal landfills. In most cases, existing leachate quantification measures only take into account one source - precipitation, which resulted in serious underestimation in China due to its waste properties: high moisture...

  4. Biogeochemistry of landfill leachate plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Kjeldsen, Peter; Bjerg, Poul Løgstrup

    2001-01-01

    is on dissolved organic matter, xenobiotic organic compounds, inorganic macrocomponents as anions and cations, and heavy metals. Laboratory as well as field investigations are included. This review is an up-date of an earlier comprehensive review. The review shows that most leachate contamination plumes...... the behavior of the contaminants in the plume as the leachate migrates away from the landfill. Diverse microbial communities have been identified in leachate plumes and are believed to be responsible for the redox processes. Dissolved organic C in the leachate, although it appears to be only slowly degradable...

  5. Combustion-gas recirculation system

    Science.gov (United States)

    Baldwin, Darryl Dean

    2007-10-09

    A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

  6. Quantification of regional leachate variance from municipal solid waste landfills in China.

    Science.gov (United States)

    Yang, Na; Damgaard, Anders; Kjeldsen, Peter; Shao, Li-Ming; He, Pin-Jing

    2015-12-01

    The quantity of leachate is crucial when assessing pollution emanating from municipal landfills. In most cases, existing leachate quantification measures only take into account one source - precipitation, which resulted in serious underestimation in China due to its waste properties: high moisture contents. To overcome this problem, a new estimation method was established considering two sources: (1) precipitation infiltrated throughout waste layers, which was simulated with the HELP model, (2) water squeezed out of the waste itself, which was theoretically calculated using actual data of Chinese waste. The two sources depended on climate conditions and waste characteristics, respectively, which both varied in different regions. In this study, 31 Chinese cities were investigated and classified into three geographic regions according to landfill leachate generation performance: northwestern China (China-NW) with semi-arid and temperate climate and waste moisture content of about 46.0%, northern China (China-N) with semi-humid and temperate climate and waste moisture content of about 58.2%, and southern China (China-S) with humid and sub-tropical/tropical climate and waste moisture content of about 58.2%. In China-NW, accumulated leachate amounts were very low and mainly the result of waste degradation, implying on-site spraying/irrigation or recirculation may be an economic approach to treatment. In China-N, water squeezed out of waste by compaction totaled 22-45% of overall leachate amounts in the first 40 years, so decreasing the initial moisture content of waste arriving at landfills could reduce leachate generation. In China-S, the leachate generated by infiltrated precipitation after HDPE geomembranes in top cover started failing, contributed more than 60% of the overall amounts over 100 years of landfilling. Therefore, the quality and placing of HDPE geomembranes in the top cover should be controlled strictly for the purpose of mitigation leachate generation.

  7. Validation for a recirculation model.

    Science.gov (United States)

    LaPuma, P T

    2001-04-01

    Recent Clean Air Act regulations designed to reduce volatile organic compound (VOC) emissions have placed new restrictions on painting operations. Treating large volumes of air which contain dilute quantities of VOCs can be expensive. Recirculating some fraction of the air allows an operator to comply with environmental regulations at reduced cost. However, there is a potential impact on employee safety because indoor pollutants will inevitably increase when air is recirculated. A computer model was developed, written in Microsoft Excel 97, to predict compliance costs and indoor air concentration changes with respect to changes in the level of recirculation for a given facility. The model predicts indoor air concentrations based on product usage and mass balance equations. This article validates the recirculation model using data collected from a C-130 aircraft painting facility at Hill Air Force Base, Utah. Air sampling data and air control cost quotes from vendors were collected for the Hill AFB painting facility and compared to the model's predictions. The model's predictions for strontium chromate and isocyanate air concentrations were generally between the maximum and minimum air sampling points with a tendency to predict near the maximum sampling points. The model's capital cost predictions for a thermal VOC control device ranged from a 14 percent underestimate to a 50 percent overestimate of the average cost quotes. A sensitivity analysis of the variables is also included. The model is demonstrated to be a good evaluation tool in understanding the impact of recirculation.

  8. Sustainable treatment of landfill leachate

    Science.gov (United States)

    Kamaruddin, Mohamad Anuar; Yusoff, Mohd. Suffian; Aziz, Hamidi Abdul; Hung, Yung-Tse

    2015-06-01

    Landfill leachate is a complex liquid that contains excessive concentrations of biodegradable and non-biodegradable products including organic matter, phenols, ammonia nitrogen, phosphate, heavy metals, and sulfide. If not properly treated and safely disposed, landfill leachate could be an impending source to surface and ground water contamination as it may percolate throughout soils and subsoils, causing adverse impacts to receiving waters. Lately, various types of treatment methods have been proposed to alleviate the risks of untreated leachate. However, some of the available techniques remain complicated, expensive and generally require definite adaptation during process. In this article, a review of literature reported from 2008 to 2012 on sustainable landfill leachate treatment technologies is discussed which includes biological and physical-chemical techniques, respectively.

  9. Recirculation nursery systems for bivalves

    NARCIS (Netherlands)

    Kamermans, P.; Blanco Garcia, A.; Joaquim, Sandra; Matias, Domitilia; Magnesen, Thorolf; Nicolas, J.; Petten, Bruno; Robert, Rene

    2016-01-01

    n order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in

  10. LANDFILL LEACHATES PRETREATMENT BY OZONATION

    Directory of Open Access Journals (Sweden)

    Jacek Leszczyński

    2016-06-01

    Full Text Available In this paper, the application of ozonation processes for stabilized landfill leachate treatment was investigated. The leachate came from a municipal sanitary landfill located nearby Bielsk Podlaski. The average values of its main parameters were: pH 8.23; COD 870 mgO2/dm3; BOD 90 mgO2/dm3; NH4+ 136.2 mgN/dm3; UV254 absorbance 0.312 and turbidity 14 NTU. The ozone dosages used were in the range of 115.5 to 808.5 mgO3/dm3 of the leachate. The maximum COD, color and UV254 absorbance removal wa.5 mgO3/dm3. After oxidation, the ratio of BOD/COD was increased from 0.1 up to 0.23.

  11. Recirculated and Energy Recovered Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft

    2003-05-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams from an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible from either a conventional linac, or from storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend from high power free-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  12. Recirculated and Energy Recovered Linacs

    CERN Document Server

    Geoffr-Ey-Kraff

    2003-01-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams FR-om an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible FR-om either a conventional linac, or FR-om storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend FR-om high power FR-ee-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  13. Migration behavior of landfill leachate contaminants through alternative composite liners

    Energy Technology Data Exchange (ETDEWEB)

    Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Top, Selin, E-mail: stop@yildiz.edu.tr; Sekman, Elif, E-mail: esekman@yildiz.edu.tr; Akkaya, Ebru, E-mail: ekoca@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr; Bilgili, M. Sinan, E-mail: mbilgili@yildiz.edu.tr

    2011-08-01

    Four identical pilot-scale landfill reactors with different alternative composite liners were simultaneously operated for a period of about 540 days to investigate and to simulate the migration behaviors of phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and heavy metals (Pb, Cu, Zn, Cr, Cd, Ni) from landfill leachate to the groundwater. Alternative landfill liners of four reactors consist of R1: Compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R2: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R3: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + bentonite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn), and R4: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + zeolite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn). Wastes representing Istanbul municipal solid wastes were disposed in the reactors. To represent bioreactor landfills, reactors were operated by leachate recirculation. To monitor and control anaerobic degradation in the reactors, variations of conventional parameters (pH, alkalinity, chloride, conductivity, COD, TOC, TKN, ammonia and alcaly metals) were also investigated in landfill leachate samples. The results of this study showed that about 35-50% of migration of organic contaminants (phenolic compounds) and 55-100% of migration of inorganic contaminants (heavy metals) to the model groundwater could be effectively reduced with the use of bentonite and zeolite materials in landfill liner systems. Although leachate contaminants can reach to the groundwater in trace concentrations, findings of this study concluded that the release of these compounds from landfill leachate to the groundwater may potentially be of an important environmental concern based on the experimental findings. - Research highlights: {yields} Migration of

  14. Multiple Regulatory Elements in the Arabidopsis NIA1 Promoter Act Synergistically to Form a Nitrate Enhancer1[W][OA

    Science.gov (United States)

    Wang, Rongchen; Guan, Peizhu; Chen, Mingsheng; Xing, Xiujuan; Zhang, Yali; Crawford, Nigel M.

    2010-01-01

    To accommodate fluctuating nutrient levels in the soil, plants modulate their metabolism and root development via signaling mechanisms that rapidly reprogram the plant transcriptome. In the case of nitrate, over 1,000 genes are induced or repressed within minutes of nitrate exposure. To identify cis-regulatory elements that mediate these responses, an enhancer screen was performed in transgenic Arabidopsis (Arabidopsis thaliana) plants. A 1.8-kb promoter fragment from the nitrate reductase gene NIA1 was identified that acts as a nitrate enhancer when fused to a 35S minimal promoter. Enhancer activity was localized to a 180-bp fragment, and this activity could be enhanced by the addition of a 131-bp fragment from the nitrite reductase promoter. A promoter construct containing the 180- and 131-bp fragments was also induced by nitrite and repressed by ammonium, indicating that it was responsive to multiple nitrogen signals. To identify specific regulatory elements within the 180-bp NIA1 fragment, a transient expression system using agroinfiltration of Nicotiana benthamiana was developed. Deletion analysis identified three elements corresponding to predicted binding motifs for homeodomain/E-box, Myb, and Alfin1 transcription factors. A fully active promoter showing nitrate and nitrite enhancer activity equivalent to that of the wild-type 180-bp fragment could be built from these three elements if the spacing between the homeodomain/E-box and Myb-Alfin1 sites was equivalent to that of the native promoter. These findings were validated in transgenic Arabidopsis plants and identify a cis-regulatory module containing three elements that comprise a nitrate enhancer in the NIA1 promoter. PMID:20668061

  15. Treating leachate by Fenton oxidation

    Directory of Open Access Journals (Sweden)

    Roger Iván Méndez Novelo

    2010-05-01

    Full Text Available Leachates are formed from liquids, mainly rainwater, percolating through solid wastes during stabilisation. Their composition is variable and highly toxic; leachate treatment is therefore a complex task. Leachates represent a high risk to health due to the Yucatan Peninsula’s highly permeable soil. The results are presented from applying the Fenton process to treating leachate from the sanitary Merida landfill, Yucatan, Mexico. The Fenton process consists of treating the contaminant load with an H2O2 and FeSO4 combination in acidic conditions. Optimal reaction time, pH value, Fenton reagent dose, post treatment coagulation – flocculation doses and increased biodegradability index were all determined. Optimal oxidation conditions and doses were 202+ minute contact time, 4 pH, 600 mg/L H2O2 concentration and 1,000 mg/L Fe. Average organic matter removal rate, measured as CODS and TOC, were 78% and 87% respectively. The biodegradability index increased from 0.07 to 0.11 during the Fenton process and up to 0.13 when the Fenton process was followed by coagulation-flocculation.

  16. Na+ recirculation and isosmotic transport.

    Science.gov (United States)

    Larsen, E H; Møbjerg, N

    2006-01-01

    The Na(+) recirculation theory for solute-coupled fluid absorption is an expansion of the local osmosis concept introduced by Curran and analyzed by Diamond & Bossert. Based on studies on small intestine the theory assumes that the observed recirculation of Na(+) serves regulation of the osmolarity of the absorbate. Mathematical modeling reproducing bioelectric and hydrosmotic properties of small intestine and proximal tubule, respectively, predicts a significant range of observations such as isosmotic transport, hyposmotic transport, solvent drag, anomalous solvent drag, the residual hydraulic permeability in proximal tubule of AQP1 (-/-) mice, and the inverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow. The model reproduces the volume responses of cells and lateral intercellular space (lis) following replacement of luminal NaCl by sucrose as well as the linear dependence of volume absorption on luminal NaCl concentration. Analysis of solvent drag on Na(+) in tight junctions provides explanation for the surprisingly high metabolic efficiency of Na(+) reabsorption. The model predicts and explains low metabolic efficiency in diluted external baths. Hyperosmolarity of lis is governed by the hydraulic permeability of the apical plasma membrane and tight junction with 6-7 mOsm in small intestine and < or = 1 mOsm in proximal tubule. Truly isosmotic transport demands a Na(+) recirculation of 50-70% in small intestine but might be barely measurable in proximal tubule. The model fails to reproduce a certain type of observations: The reduced volume absorption at transepithelial osmotic equilibrium in AQP1 knockout mice, and the stimulated water absorption by gallbladder in diluted external solutions. Thus, it indicates cellular regulation of apical Na(+) uptake, which is not included in the mathematical treatment.

  17. Ultrasound assisted biogas production from landfill leachate

    Energy Technology Data Exchange (ETDEWEB)

    Oz, Nilgün Ayman, E-mail: nilgunayman@comu.edu.tr; Yarimtepe, Canan Can

    2014-07-15

    Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency

  18. Behavior of engineered nanoparticles in landfill leachate.

    Science.gov (United States)

    Bolyard, Stephanie C; Reinhart, Debra R; Santra, Swadeshmukul

    2013-08-01

    This research sought to understand the behavior of engineered nanoparticles in landfill leachate by examining the interactions between nanoparticles and leachate components. The primary foci of this paper are the effects of ZnO, TiO2, and Ag nanoparticles on biological landfill processes and the form of Zn, Ti, and Ag in leachate following the addition of nanoparticles. Insight into the behavior of nanoparticles in landfill leachate was gained from the observed increase in the aqueous concentrations over background for Zn, Ti, and Ag in some tested leachates attributed to leachate components interacting with the nanoparticle coatings resulting in dispersion, dissolution/dissociation, and/or agglomeration. Coated nanoparticles did not affect biological processes when added to leachate; five-day biochemical oxygen demand and biochemical methane potential results were not statistically different when exposed to nanoparticles, presumably due to the low concentration of dissolved free ionic forms of the associated metals resulting from the interaction with leachate components. Chemical speciation modeling predicted that dissolved Zn in leachate was primarily associated with dissolved organic matter, Ti with hydroxide, and Ag with hydrogen sulfide and ammonia; less than 1% of dissolved Zn and Ag was in the free ionic form, and free ionic Ti and Ag concentrations were negligible.

  19. Cadmium complexation by solid waste leachates

    DEFF Research Database (Denmark)

    Xu Ze Lun; Christensen, Thomas H.

    1989-01-01

    A previously reported method for determination of Cd species in solid waste leachates has been applied to ten leachate samples representing five different types of solid waste: refuse compost, flyash from coal combustion, sewage sludge, refuse incineration residues and landfilled municipal waste......, slowly labile complexes and stable complexes. Leachates originating from the same type of solid waste showed different fractions of Cd, in particular with respect to free divalent Cd and stable Cd complexes. Only coal flyash showed almost identical fractions of Cd in the two leachates. The latter is due...

  20. Toxicity of waste gasification bottom ash leachate.

    Science.gov (United States)

    Sivula, Leena; Oikari, Aimo; Rintala, Jukka

    2012-06-01

    Toxicity of waste gasification bottom ash leachate from landfill lysimeters (112 m(3)) was studied over three years. The leachate of grate incineration bottom ash from a parallel setup was used as reference material. Three aquatic organisms (bioluminescent bacteria, green algae and water flea) were used to study acute toxicity. In addition, an ethoxyresorufin-O-deethylase (EROD) assay was performed with mouse hepatoma cells to indicate the presence of organic contaminants. Concentrations of 14 elements and 15 PAH compounds were determined to characterise leachate. Gasification ash leachate had a high pH (9.2-12.4) and assays with and without pH adjustment to neutral were used. Gasification ash leachate was acutely toxic (EC(50) 0.09-62 vol-%) in all assays except in the algae assay with pH adjustment. The gasification ash toxicity lasted the entire study period and was at maximum after two years of disposal both in water flea (EC(50) 0.09 vol-%) and in algae assays (EC(50) 7.5 vol-%). The grate ash leachate showed decreasing toxicity during the first two years of disposal in water flea and algae assays, which then tapered off. Both in the grate ash and in the gasification ash leachates EROD-activity increased during the first two years of disposal and then tapered off, the highest inductions were observed with the gasification ash leachate. The higher toxicity of the gasification ash leachate was probably related to direct and indirect effects of high pH and to lower levels of TOC and DOC compared to the grate ash leachate. The grate ash leachate toxicity was similar to that previously reported in literature, therefore, confirming that used setup was both comparable and reliable. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Leachate characterization and identification of dominant pollutants using leachate pollution index for an uncontrolled landfill site

    Directory of Open Access Journals (Sweden)

    S. De

    2016-03-01

    Full Text Available Landfill leachates are potential threats for environmental degradation. This study was conducted to determine the leachate quality, to identify the dominant pollutants and to evaluate the leachate pollution potential of an active and closed dumping ground of an uncontrolled municipal solid waste landfill site in Kolkata, India using leachate pollution index. The results of the physico-chemical and biological analyses of leachate indicated that landfill site was in its methanogenic phase. Among the analysed leachate pollutants, TDS, BOD5, COD, TKN, NH3-N, Cl¯, TCB, Pb, and Hg surpassed the leachate discharge standards for inland surface water as specified by the municipal solid waste (Management and Handling Rules, 2013 for both the dumping grounds. Moreover the concentrations of total Cr and Zn also exceeded the leachate disposal standards for the active dumping ground. The leachate pollution potentialities of both the active and closed dumping grounds were comparable as the overall LPI obtained 34.02 and 31.80 respectively. The overall LPI, LPI organic (LPIor, LPI inorganic (LPIin and LPI heavy metals (LPIhm of both the dumping grounds largely exceeded the LPI and sub-LPI values for treated leachate before disposal to the inland surface water. In terms of the individual pollution rating, total coliform bacteria, TKN, NH3-N and Hg were identified as the dominant pollutants and major contributing factors for the leachate pollution potential.

  2. TANK MIXING STUDY WITH FLOW RECIRCULATION

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.

    2014-06-25

    The primary objective of this work is to quantify the mixing time when two miscible fluids are mixed by one recirculation pump and to evaluate adequacy of 2.5 hours of pump recirculation to be considered well mixed in SRS tanks, JT-71/72. The work scope described here consists of two modeling analyses. They are the steady state flow pattern analysis during pump recirculation operation of the tank liquid and transient species transport calculations based on the initial steady state flow patterns. The modeling calculations for the mixing time are performed by using the 99% homogeneity criterion for the entire domain of the tank contents.

  3. Qualitative Research and Evaluation of Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Irina Kačinskaja

    2013-12-01

    Full Text Available Currently, depositing municipal waste in landfills is the dominating method in Lithuania. A large amount of landfill leachate is the main environmental problem. Municipal waste landfill leachate is characterized by high biochemical oxygen demand (BOD containing a number of heavy metals and concentration of organic compounds. The colmatation of landfill leachate collection systems is another burning problem that occurs due to certain characteristics of leachate such as suspended solids, an increase in calcium and magnesium concentrations and vital activity of microorganisms. Therefore, it is necessary to examine conditions affecting these parameters. The paper presents and analyses the characteristics of experimental data, assesses the factors having the greatest influence on recent development and introduces the measures that should be taken into account so that to the ensure optimal operation of the systems for collecting municipal waste landfill leachate.Article in Lithuanian

  4. Landfill leachate treatment in assisted landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    HE Pin-jing; QU Xian; SHAO Li-ming; LEE Duu-jong

    2006-01-01

    Landfill is the major disposal route of municipal solid waste(MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95%(61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas.

  5. Review on Landfill Leachate Treatments

    Directory of Open Access Journals (Sweden)

    Abdulhussain A. Abbas

    2009-01-01

    Full Text Available Problem Statement: Sanitary landfilling is the most common way to eliminate solid urban wastes. An important problem associated to landfills is the production of leachates. This study is a review of landfill leachate treatments. Approach: The advantages and disadvantages of the various existing leachate treatments discussed under the items: (i Leachate channeling (combined treatment with domestic sewage, recycling (ii Biological processing (aerobic and anaerobic (iii Chemical/physical treatment (flotation, coagulation/flocculation, chemical precipitation, adsorption, ammonium stripping, chemical oxidation, ion exchange and electrochemical treatment (iv Membrane filtration (microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Conclusion: The major fraction of old or biologically treated leachate was large recalcitrant organic molecules that are not easy removed during biological treatment. So that, in order to meet strict quality standards for direct discharge of leachate into the surface water, a development of integrated methods of treatment, a combination of biological, chemical, physical and membrane process steps, were required. Today, the use of membrane technologies, more especially Reverse Osmosis (RO, either as a main step in a landfill leachate treatment chain or as single post-treatment step had shown to be an indispensable means of achieving purification.

  6. Ultrasound assisted biogas production from landfill leachate.

    Science.gov (United States)

    Oz, Nilgün Ayman; Yarimtepe, Canan Can

    2014-07-01

    The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman's test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (pbiogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann-Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p<0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.

  7. [Impact of Salinity on Leachate Treatment and N2O Releases from Semi-aerobic Aged-refuse Bioreactor].

    Science.gov (United States)

    Li, Wei-hua; Sun, Ying-jie; Liu, Zi-liang; Ma, Qiang; Yang, Qiang

    2016-02-15

    Semi-aerobic Aged-refuse Bioreactor (SAARB) has a good effect on nitrogen removal in leachate, but a strong greenhouse gas (N2O) was generated during the nitrification and denitrification process. The effect of salinity (7-30 g x L(-1)) on the leachate treatment and the N2O production from SAARB system was investigated. Experimental results showed that salinity ranging from 7 to 30 g x L(-1) had no significant effect on COD removal, and the removal efficiency was always more than 85%. On the contrary, it had a strong influence on the removal of nitrogen. The removal efficiencies of NH4+ -N and TN decreased from 98. 23% and 91.48% at 7 g x L(-1) salt to 31.75% and 34.24% at 30 g x L(-1) salt, respectively. Moreover, there was significant nitrite (NO2- -N) accumulation in the presence of 30 g x L(-1) salt. Meanwhile, salinity had different inhibition strength on nitrification and denitrification bacteria, and the order of inhibition strength was as follows: nitrification bacteria > denitrification bacteria. In addition, the N2O production increased with salinity concentration, and the highest N2O accumulation (1397 microg +/- 369.88 microg) was observed with addition of 30 g x L(-1) salt, which accounted for 8.87%o of the total nitrogen removal. Meanwhile, it was 6-117 times higher in the presence of 30 g x L(-1) salt than that in low salinity conditions (7-20 g x L(-1)). And the peak time of the N2O production showed a delayed trend. These results indicated that salinity recirculation in leachate had a negative effect on the nitrogen removal and N2O production. Overall, salinity seemed to be a key parameter during leachate recirculation.

  8. Characterization and treatment of municipal landfill leachates

    Energy Technology Data Exchange (ETDEWEB)

    Welander, Ulrika

    1998-03-01

    The efficiency of different leachate treatment methods for the removal of refractory organic compounds and ammonium-nitrogen was investigated. The methods evaluated were nitrification, denitrification, adsorption onto activated carbon, precipitation by ferric chloride or aluminum sulphate and oxidation by ozone or Fenton`s reagent. Furthermore, analyses were performed on leachates from municipal landfills of different kinds (a biocell deposit, a conventional mixed landfill containing household and industrial waste, and an ash deposit) in order to study the leachate composition in regard to various hydrophobic organic compounds as a function of the type of waste deposited. The results suggested that, in order to achieve a satisfactory removal of both ammonium-nitrogen and organic substances, the treatment of methanogenic leachates should be performed through a process combining biological and physical or chemical stages. When the biological treatment was not combined with a physical or a chemical process a COD removal of only 20-30% was achieved, whereas the toxicity of the leachate was significantly reduced. In contrast, a combination of nitrification and either adsorption onto activated carbon or oxidation using Fenton`s reagent resulted in a COD removal of about 80%, although certain specific organic compounds, such as phthalates, were unaffected by the treatment. A combination of nitrification, precipitation by ferric chloride and adsorption onto activated carbon removed 96% of the TOC. The analyses of leachates from municipal landfills of different types showed the leachate from the ash deposit to contain more C4-substituted phenols than the other leachates and to likewise contain alkanes, which the others did not 154 refs, 12 figs, 4 tabs

  9. Diagnostics For Recirculating And Energy Recovered Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey A. Krafft; Jean-Claude Denard

    2002-12-18

    In this paper, the electron beam diagnostics developed for recirculating electron accelerators will be reviewed. The main novelties in dealing with such accelerators are: to have sufficient information and control possibilities for the longitudinal phase space, to have means to accurately set the recirculation path length, and to have a means to distinguish the beam passes on measurements of position in the linac proper. The solutions to these problems obtained at Jefferson Laboratory and elsewhere will be discussed. In addition, more standard instrumentation (profiling and emittance measurements) will be reviewed in the context of recirculating linacs. Finally, and looking forward, electron beam diagnostics for applications to high current energy recovered linacs will be discussed.

  10. Magnetic and Electrical Properties of Leachate

    Directory of Open Access Journals (Sweden)

    Kartika Kirana

    2011-11-01

    Full Text Available Heavy metals content as well as magnetic and electrical properties of leachate from Sarimukti, West Java were studied in an attempt to seek correlation between heavy metals content and magnetic/electrical properties. Such correlation is expected to open the way for the use of magnetic/electrical properties as proxy indicators for the concentration of heavy metals in the leachate. The number of leachate samples studied is 21; 15 were taken spatially at depth of 1 m while the remaining 6 samples were taken vertically at a particular point. Measurement results showed that the heavy metals content in the leachate has a smaller concentration, except for Fe. The correlation between magnetic susceptibility and heavy metals content was found to be not so significant. The best correlation coefficient between magnetic susceptibility with heavy metals in leachate was found in Zn. Correlation between electrical conductivity and heavy metal is also not so significant, except for Zn and Cd. The use of magnetic properties as proxy indicator for heavy metals content in leachate is plausible provided that the magnetic susceptibility exceeds certain threshold value. Correlation between magnetic susceptibility, electrical conductivity and heavy metal content would be good if each quantity has a large value.

  11. Sodium recirculation and isotonic transport in toad small intestine

    DEFF Research Database (Denmark)

    Nedergaard, Signe Nielsen; Larsen, Erik Hviid; Ussing, Hans H.

    1999-01-01

    Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi......Small intestine; leaky epithelia; solute-coupled water transport; Na*O+ recirculation; lateral intercellular space; flux ratio analysi...

  12. Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.

    1996-01-01

    This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: (1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 micrometer) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2-4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.

  13. N2O emissions from an intermittently aerated semi-aerobic aged refuse bioreactor: Combined effect of COD and NH4(+)-N in influent leachate.

    Science.gov (United States)

    Li, Weihua; Sun, Yingjie; Bian, Rongxing; Wang, Huawei; Zhang, Dalei

    2017-08-12

    The carbon-nitrogen ratio (COD/NH4(+)-N) is an important factor affecting nitrification and denitrification in wastewater treatment; this factor also influences nitrous oxide (N2O) emissions. This study investigated two simulated intermittently aerated semi-aerobic aged refuse bioreactors (SAARB) filled with 8-year old aged refuse (AR). The research analyzed how differences in and the combination of influent COD and NH4(+)-N impact N2O emissions in leachate treatment. Experimental results showed that N2O emissions increased as the influent COD/NH4(+)-N decreased. The influent COD had a greater effect on N2O emissions than NH4(+)-N at the same influent ratios of COD/NH4(+)-N (2.7 and 8.0, respectively). The maximum N2O emission accounted for 8.82±2.65% of the total nitrogen removed from the influent leachate; the maximum level occurred when the COD was 2000mg/L. An analysis of differences in influent carbon sources at the same COD/NH4(+)-N ratios concluded that the availability of biodegradable carbon substrates (i.e. glucose) is an important factor affecting N2O emissions. At a low influent COD/NH4(+)-N ratio (2.7), the N2O conversion rate was greater when there were more biodegradable carbon substrates. Although the SAARB included the N2O generation and reduction processes, N2O reduction mainly occurred later in the process, after leachate recirculation. The maximum N2O emission rate occurred in the first hour of single-period (24h) experiments, as leachate contacted the surface AR. In practical SAARB applications, N2O emissions may be reduced by measures such as reducing the initial recirculation loading of NH4(+)-N substrates, adding a later supplement of biodegradable carbon substrates, and/or prolonging hydraulic retention time (HRT) of influent leachate. Copyright © 2017. Published by Elsevier Ltd.

  14. Nitrogen Removal from Landfill Leachate by Microalgae

    Directory of Open Access Journals (Sweden)

    Sérgio F. L. Pereira

    2016-11-01

    Full Text Available Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+ concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates.

  15. Nitrogen Removal from Landfill Leachate by Microalgae

    Science.gov (United States)

    Pereira, Sérgio F. L.; Gonçalves, Ana L.; Moreira, Francisca C.; Silva, Tânia F. C. V.; Vilar, Vítor J. P.; Pires, José C. M.

    2016-01-01

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates. PMID:27869676

  16. Nitrogen Removal from Landfill Leachate by Microalgae.

    Science.gov (United States)

    Pereira, Sérgio F L; Gonçalves, Ana L; Moreira, Francisca C; Silva, Tânia F C V; Vilar, Vítor J P; Pires, José C M

    2016-11-17

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N-NH₄⁺) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N-NH₄⁺ concentration. In terms of nutrients uptake, an effective removal of N-NH₄⁺ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N-NO₃(-) removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates.

  17. LEACHATE CLOGGING ASSESSMENT OF GEOTEXTILE AND SOIL LANDFILL FILTERS

    Science.gov (United States)

    The liquids management strategy for any municipal or hazardous waste landfill requires a knowledgeable design strategy for the leachate collection system located at the base of the waste mass. Such leachate collection systems generally consist of sumps, perforated pipes, drainag...

  18. Biological Treatment of Leachate using Sequencing Batch Reactor

    OpenAIRE

    2014-01-01

    Abstract   In Sri Lanka municipal solid waste is generally disposed in poorly managed open dumps which lack liner systems and leachate collection systems. Rain water percolates through the waste layers to produce leachate which drains in to ground water and finally to nearby water bodies, degrading the quality of water. Leachate thus has become a major environmental concern in municipal waste management and treatment of leachate is a major challenge for the existing and proposed landfill si...

  19. Landfilling: Bottom Lining and Leachate Collection

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    from entering the groundwater or surface water. The bottom lining system should cover the full footprint area of the landfill, including both the relatively flat bottom and the sideslopes in the case of an excavated configuration. This prevents the lateral migration of leachate from within the landfill...... triple) liners, are extremely effective in preventing leachate from entering into the environment. In addition, the risk of polluting the groundwater at a landfill by any leakage of leachate depends on several factors related to siting of the landfill: distance to the water table, distance to surface...... water bodies, and the properties of the soil beneath the landfill. In addition to the lining and drainage systems described in this chapter, the siting and hydrogeology of the landfill site (Chapter 10.12) and the top cover (Chapter 10.9) are also part of the barrier system, contributing to reducing...

  20. Electrocoagulation and decolorization of landfill leachate

    Science.gov (United States)

    Mussa, Zainab Haider; Othman, Mohamed Rozali; Abdullah, Md Pauzi

    2013-11-01

    In this study, several operating conditions such as electrode material, treatment time, applied voltage, Cl□ concentration and PH of solution were tested on treatability of landfill leachate by using electrocoagulation (EC) method. According to the results, EC method can be used efficiently for the treatment of landfill leachate by using proper operating conditions. The best removal rats were obtained when C (rod) electrode as anode, operating time is 120 min, voltage applied is 10 V, NaCl concentration is 5.85 g/L and the raw PH, for these conditions, 70% color removal was obtained.

  1. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  2. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  3. Re-circulating linac vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-05-09

    The vacuum system for a proposed 2.5 GeV, 10{Mu}A recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10{Mu}A average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing.

  4. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors.

    Science.gov (United States)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac

    2015-07-01

    Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10months. The hybrid bioreactors were operated in an aerobic-anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia-nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75d and 60d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4L/kgvs and 113.2L/kgvs. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  5. High Power Picosecond Laser Pulse Recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  6. High-power picosecond laser pulse recirculation.

    Science.gov (United States)

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  7. Influence of landfill structures on stabilization of fully recycled leachate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The experiment was conducted to treat the leachate from two simulating columns by recycling to the columns themselves without being discharged into the enviroment. The columns were employed to simulate anaerobic and semi-aerobic landfills separately. The influence of landfill structure on stabilization of fully recycled leachate was studied. The results show that semi-aerobic landfill structure accelerates the stabilization of leachate recycled. The full recycle of leachate in semi-aerobic landfill is a very feasible and effective technology for leachate treatment with low cost and energy saving especially in arid and rare rainfall regions. Meanwhile, the environmental impact of landfill can be greatly minimized.

  8. Kaolinite sorption of Cd, Ni and Cu from landfill leachates: influence of leachate composition.

    Science.gov (United States)

    Petrangeli Papini, M; Majone, M; Rolle, E

    2001-01-01

    Heavy metal speciation in landfill leachates plays a significant role in determining the mobility during the percolation through soils. The complexation characteristics of landfill leachate directly affects heavy metal solubility and the extent of the interaction with soils, lowering or raising the sorbed amount depending on the relative affinity of the complexed metal and uncomplexed form to soil adsorption sites. In this paper, the adsorption of Cd, Ni and Cu onto kaolinite from three leachates (collected from landfill at different fermentation stage) is studied, also in comparison with metal speciation by two different operative procedures. The heavy metals, at their natural concentration, were divided into operational classes according to an exchange-based procedure and by fractionation on the basis of molecular weight (exchange onto Chelex100 resin and ultrafiltration, respectively). All the experiments were performed also on synthetic solutions designed according to leachate composition and theoretical speciation. The experimental results have shown leachate complexing capacity is strongly dependent on landfill age, and that broad parameters such as COD, DOC, pH, ionic strength and VFA concentration are not able to predict it. It is notheworthy that the strong complexing capacity of leachate can cause extraction of metals from the solid phase instead of adsorption from the liquid one.

  9. Nonequilibrium free diffusion in seed leachate

    Science.gov (United States)

    Ortiz G., Luis; Riquelme P., Pablo; Guzmán, R.

    2013-11-01

    In this work, we use a Schlieren-like Near Field Scattering (SNFS) setup to study nonequilibrium free diffusion behavior of a colloidal solution obtained from seeds leachate. The main objective is to compare the temporal behavior of the diffusion coefficient of seed leachate with an electric conductivity based vigor test. SNFS sizing measurements, based on Mie theory, were carried out to ensure its reliability and sensitivity. Then, we performed a typical nonequilibrium free diffusion experiment of a glycerol-water mixture. In this way, we confirmed that SNFS setup is sensitive to giant concentration fluctuations of nanocolloidal solutions. The results obtained in this stage reproduce properly the data reported elsewhere in literature. Moreover, seed leachate diffuse, in water, in a similar way that glycerol does. In both cases we used the same method (dynamic structure factor) to determine thermo-physical properties. We show that time evolution of diffusion coefficient of Lupinus Albus leachate exhibits three defined regimes as electric conductivity measurements. The results also exhibit a correspondence between the behavior of the diffusion coefficient and electric conductivity values of the two regions in the temporal range studied. Finally, we discuss biological processes involved in germination that could modulate this dependence, and the role played by the electrolytic nature of solutes.

  10. Treatment of Landfill Leachate at Army Facilities.

    Science.gov (United States)

    1983-08-01

    e.g., training residues; propellant, explosive , or pyrotechnic residues; and abandoned transformers. Such materials may be mixed with the general...Schanche, L. J. Benson, M. J. Staub , and M. A. Kamiya, Charateristics, Control, and Treatment of Leachate at Military Installations, Interim Report N-97

  11. Exhaust gas recirculation in a homogeneous charge compression ignition engine

    Science.gov (United States)

    Duffy, Kevin P.; Kieser, Andrew J.; Rodman, Anthony; Liechty, Michael P.; Hergart, Carl-Anders; Hardy, William L.

    2008-05-27

    A homogeneous charge compression ignition engine operates by injecting liquid fuel directly in a combustion chamber, and mixing the fuel with recirculated exhaust and fresh air through an auto ignition condition of the fuel. The engine includes at least one turbocharger for extracting energy from the engine exhaust and using that energy to boost intake pressure of recirculated exhaust gas and fresh air. Elevated proportions of exhaust gas recirculated to the engine are attained by throttling the fresh air inlet supply. These elevated exhaust gas recirculation rates allow the HCCI engine to be operated at higher speeds and loads rendering the HCCI engine a more viable alternative to a conventional diesel engine.

  12. The bio-ethanol production with the thin stillage recirculation

    Directory of Open Access Journals (Sweden)

    M. Rakin

    2009-01-01

    Full Text Available In this paper, the bioethanol production with the thin stillage recirculation in mashing was investigated. The mashing was performed with recirculation of: 0, 10, 20 and 30 % of the thin stillage. The thin stillage recirculation was repeated six times. In the experiment without the thin stillage, the recirculation bioethanol yield (compared to the theoretical yield was 97.96 %, which implicates that the experiment conditions were chosen and performed well. With the addition of the thin stillage, the bioethanol yield increased and was above 100 %. Higher bioethanol yield than 100 % can be explained by the fact that the thin stillage contains carbohydrates, amino acids and yeast cells degradation products. The bioethanol yield increased with the increased number of thin stillage recirculation cycles. Dry matter content in fermenting slurry increased with the increased thin stillage quantity and the number of the thin stillage recirculation cycles (8.04 % for the first and 9.40 % for the sixth cycle. Dry matter content in thin stillage increased with the increased thin stillage quantity and the number of thin stillage recirculation cycles. Based on the obtained results it can be concluded that thin stillage recirculation increased the bioethanol yield. The highest bioethanol yields were obtained with recirculation of 10% thin stillage.

  13. Triplet Focusing for Recirculating Linear Muon Accelerators

    CERN Document Server

    Keil, Eberhard

    2001-01-01

    Focusing by symmetrical triplets is studied for the linear accelerator lattices in recirculating muon accelerators with several passes where the ratio of final to initial muon energy is about four. Triplet and FODO lattices are compared. At similar acceptance, triplet lattices have straight sections for the RF cavities that are about twice as long as in FODO lat-tices. For the same energy gain, the total lengths of the linear accelerators with triplet lattices are about the same as of those with FODO lattices.

  14. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  15. In-tank recirculating arsenic treatment system

    Science.gov (United States)

    Brady, Patrick V.; Dwyer, Brian P.; Krumhansl, James L.; Chwirka, Joseph D.

    2009-04-07

    A low-cost, water treatment system and method for reducing arsenic contamination in small community water storage tanks. Arsenic is removed by using a submersible pump, sitting at the bottom of the tank, which continuously recirculates (at a low flow rate) arsenic-contaminated water through an attached and enclosed filter bed containing arsenic-sorbing media. The pump and treatment column can be either placed inside the tank (In-Tank) by manually-lowering through an access hole, or attached to the outside of the tank (Out-of-Tank), for easy replacement of the sorption media.

  16. Multi-frequency recirculating planar magnetrons

    Science.gov (United States)

    Greening, Geoffrey B.; Jordan, Nicholas M.; Exelby, Steven C.; Simon, David H.; Lau, Y. Y.; Gilgenbach, Ronald M.

    2016-08-01

    The multi-frequency recirculating planar magnetron (MFRPM) is the first magnetron capable of simultaneous generation of significantly different output frequencies (1 and 2 GHz) in a single operating pulse. Design and simulation of a prototype MFRPM were followed by hardware fabrication and experimental verification using the Michigan Electron Long Beam Accelerator with a Ceramic insulator at -300 kV, 1-5 kA, and 0.14-0.23 T axial magnetic field. Preliminary results demonstrated simultaneous generation of microwave pulses near 1 GHz and 2 GHz at powers up to 44 MW and 21 MW, respectively, with peak total efficiencies up to 9%.

  17. Biodegradability of leachates from Chinese and German municipal solid waste

    Institute of Scientific and Technical Information of China (English)

    SELIC E.; WANG Chi; BOES N., HERBELL J.D.

    2007-01-01

    The quantitative and qualitative composition of Chinese municipal solid waste (MSW) differs significantly from German waste. The focus of this paper is on whether these differences also lead to dissimilar qualities of leachates during storage or landfilling. Leachates ingredients determine the appropriate treatment technique. MSW compositions of the two cities Guilin (China) and Essen (Germany), each with approx. 600000 inhabitants, are used to simulate Chinese and German MSW types. A sequencing batch reactor (SBR) is used, combining aerobic and anaerobic reaction principles, to test the biodegradability of leachates. Leachates are tested for temperature, pH-value, redox potentials, and oxygen concentration. Chemical oxygen demand (COD) values are determined. Within 8 h, the biodegradation rates for both kinds of leachates are more than 90%. Due to the high organic content of Chinese waste, the degradation rate for Guilin MSW leachate is even higher, up to 97%. The effluent from SBR technique is suitable for direct discharge into bodies of water.

  18. Photodegradation of roxarsone in poultry litter leachates.

    Science.gov (United States)

    Bednar, A J; Garbarino, J R; Ferrer, I; Rutherford, D W; Wershaw, R L; Ranville, J F; Wildeman, T R

    2003-01-20

    Arsenic compounds have been used extensively in agriculture in the US for applications ranging from cotton herbicides to animal feed supplements. Roxarsone (3-nitro-4-hydroxyphenylarsonic acid), in particular, is used widely in poultry production to control coccidial intestinal parasites. It is excreted unchanged in the manure and introduced into the environment when litter is applied to farmland as fertilizer. Although the toxicity of roxarsone is less than that of inorganic arsenic, roxarsone can degrade, biotically and abiotically, to produce more toxic inorganic forms of arsenic, such as arsenite and arsenate. Experiments were conducted on aqueous litter leachates to test the stability of roxarsone under different conditions. Laboratory experiments have shown that arsenite can be cleaved photolytically from the roxarsone moiety at pH 4-8 and that the degradation rate increases with increasing pH. Furthermore, the rate of photodegradation increases with nitrate and natural organic matter concentration, reactants that are commonly found in poultry-litter-water leachates. Additional photochemical reactions rapidly oxidize the cleaved arsenite to arsenate. The formation of arsenate is not entirely undesirable, because it is less mobile in soil systems and less toxic than arsenite. A possible mechanism for the degradation of roxarsone in poultry litter leachates is proposed. The results suggest that poultry litter storage and field application practices could affect the degradation of roxarsone and subsequent mobilization of inorganic arsenic species.

  19. Improvement of Landfill Leachate Biodegradability with Ultrasonic Process

    OpenAIRE

    Mahvi Amirhossein; Roodbari Aliakbar; Nabizadeh Nodehi Ramin; Naseri Simin; Dehghani Mohammadhadii; Alimohammadi Mahmood

    2012-01-01

    Leachate from mature landfills is typically characterized by high ammonium (NH4+) content, low biodegradability (low BOD5/COD ratio) and high fraction of refractory and large organic molecules such as humic and fulvic acids. Mature leachate effluents are known to contain recalcitrant and/or non-biodegradable organic substances and biological processes are not efficient in these cases. A promising alternative to complete oxidation of biorecalcitrant leachate is the use of ultrasonic process as...

  20. An investigation of recalcitrant organic compounds in leachates

    OpenAIRE

    2009-01-01

    Recalcitrant organic compounds remain a key challenge in landfill leachate management as they are resistant to microbial degradation and have potential to damage the water environment. Conventional leachate characterisation methods are time consuming and limited by their inability to provide compositional analysis. This research therefore investigates the characteristics of recalcitrant organic compounds in leachates and undertakes a feasibility study of the possible use of UV absorption and ...

  1. Production of market size pikeperch (Sander lucioperca) in a pilot recirculation system

    NARCIS (Netherlands)

    Schram, E.; Philipsen, E.

    2003-01-01

    A pilot recirculation system was designed and constructed to investigate the production characteristics of pikeperch in recirculation systems. The design is based on a recirculation system for eel production.

  2. 40 CFR 1065.127 - Exhaust gas recirculation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Exhaust gas recirculation. 1065.127 Section 1065.127 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Equipment Specifications § 1065.127 Exhaust gas recirculation. Use...

  3. Phytotoxicity of landfill leachate on willow--Salix amygdalina L.

    Science.gov (United States)

    Bialowiec, Andrzej; Randerson, Peter F

    2010-01-01

    Because of low investment and operational costs, interest is increasing in the use of willow plants in landfill leachate disposal. Toxic effects of leachate on the plants should be avoided in the initial period of growth and phytotoxicological testing may be helpful to select appropriate leachate dose rates. The aim of this study was to determine the phytotoxicity of landfill leachate on young willow (Salix amygdalina L.) cuttings, as a criterion for dose rate selection in the early phase of growth. Over a test period of 6 weeks plants were exposed to six concentrations of landfill leachate solutions (0%; 6.25%; 12.5%; 25%; 50% and 100%), under two different regimes. In regime A willow plants were cultivated in leachate solution from the beginning, whereas in regime B they were grown initially in clean water for 4 weeks, after which the water was exchanged for leachate solutions. The lowest effective concentration causing toxic effects (LOEC) was calculated (pWillow plants were able to survive in landfill leachate solutions with electrical conductivity (EC) values up to 5.0 mS/cm in regime A, whereas in regime B plants were killed when EC exceeded 3.0 mS/cm. This indicates an ability of willow plants to tolerate higher strengths of landfill leachate if they are cultivated in such concentrations from the beginning.

  4. Leachate migration and its impacts on the environment

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Y. S

    1998-12-01

    In Korea there are hundreds of landfill sites all over the peninsular and the leachate problem is one of the national concern. Heavy precipitation especially during hot summers creates the fast degradation of waste products in the site which accelerates the migration of the leachate. In this report current status of the landfill site related issues were studied along with potential solutions on them. Also the fundamental mathematical derivations to describe the movement of the leachate in geologic medium was studied. These results shall be used to assess the leachate migration in the specific landfill site in the 2nd R and D year.

  5. Water hyacinth system for municipal landfill leachate treatment

    Energy Technology Data Exchange (ETDEWEB)

    El-Gendy, A.S.; Biswas, N.; Bewtra, J.K. [Univ. of Windsor, Dept. of Civil and Environmental Engineering, Windsor, Ontario (Canada)

    2002-06-15

    Batch experiments were conducted in a green house environment to investigate the ability of water hyacinth (Eichhornia crassipes) to treat municipal landfill leachate. The experiments were carried out on leachate samples collected from Essex-Windsor Regional Landfill, Windsor, Ontario, Canada. Three leachate dilutions were used in the study. In addition to plant growth, leachate constituents such as pH, alkalinity, chemical oxygen demand (COD), ammonia, total Kjeldahl nitrogen (TKN), nitrate, reactive phosphate, total iron, potassium and chloride were also determined. These parameters were analyzed at different times covering the duration of the experiments. The experimental data showed that water hyacinth system was capable of reducing total nitrogen in the leachate. The pH level remained around 8.0. High consumption of alkalinity during the first three weeks was observed, which could be attributed to nitrification of ammonia. Ammonia nitrogen and total reactive phosphate were removed completely, whereas potassium and chloride remained unchanged. Landfill leachate has a negative impact on plant growth. As the concentration of leachate increases, its toxicity increases resulting in the decrease in the growth of water hyacinth. Water hyacinth system seems to be a promising technology for treating municipal landfill leachate. However, additional studies are required to investigate the system tolerance for some pollutants that might be present in leachate at wide ranges of concentrations such as salinities, hydrogen ion concentration, and heavy metals. (author)

  6. Beam Dynamics Studies in Recirculating Machines

    CERN Document Server

    Pellegrini, Dario; Latina, A

    The LHeC and the CLIC Drive Beam share not only the high-current beams that make them prone to show instabilities, but also unconventional lattice topologies and operational schemes in which the time sequence of the bunches varies along the machine. In order to asses the feasibility of these projects, realistic simulations taking into account the most worrisome effects and their interplays, are crucial. These include linear and non-linear optics with time dependent elements, incoherent and coherent synchrotron radiation, short and long-range wakefields, beam-beam effect and ion cloud. In order to investigate multi-bunch effects in recirculating machines, a new version of the tracking code PLACET has been developed from scratch. PLACET2, already integrates most of the effects mentioned before and can easily receive additional physics. Its innovative design allows to describe complex lattices and track one or more bunches accordingly to the machine operation, reproducing the bunch train splitting and recombinat...

  7. Nutrient Management in Recirculating Hydroponic Culture

    Science.gov (United States)

    Bugbee, Bruce

    2004-01-01

    There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

  8. Recirculation bubbler for glass melter apparatus

    Science.gov (United States)

    Guerrero, Hector; Bickford, Dennis

    2007-06-05

    A gas bubbler device provides enhanced recirculation of molten glass within a glass melter apparatus. The bubbler device includes a tube member disposed within a pool of molten glass contained in the melter. The tube member includes a lower opening through which the molten glass enters and upper slots disposed close to (above or below) the upper surface of the pool of molten glass and from which the glass exits. A gas (air) line is disposed within the tube member and extends longitudinally thereof. A gas bubble distribution device, which is located adjacent to the lower end of the tube member and is connected to the lower end of the gas line, releases gas through openings therein so as to produce gas bubbles of a desired size in the molten glass and in a distributed pattern across the tube member.

  9. A detailed BWR recirculation loop model for RELAP

    Energy Technology Data Exchange (ETDEWEB)

    Araiza-Martínez, Enrique, E-mail: enrique.araiza@inin.gob.mx; Ortiz-Villafuerte, Javier, E-mail: javier.ortiz@inin.gob.mx; Castillo-Durán, Rogelio, E-mail: rogelio.castillo@inin.gob.mx

    2017-01-15

    Highlights: • A new detailed BWR recirculation loop model was developed for RELAP. • All jet pumps, risers, manifold, suction and control valves, and recirculation pump are modeled. • Model is tested against data from partial blockage of two jet pumps. • For practical applications, simulation results showed good agreement with available data. - Abstract: A new detailed geometric model of the whole recirculation loop of a BWR has been developed for the code RELAP. This detailed model includes the 10 jet pumps, 5 risers, manifold, suction and control valves, and the recirculation pump, per recirculation loop. The model is tested against data from an event of partial blockage at the entrance nozzle of one jet pump in both recirculation loops. For practical applications, simulation results showed good agreement with data. Then, values of parameters considered as figure of merit (reactor power, dome pressure, core flow, among others) for this event are compared against those from the common 1 jet pump per loop model. The results show that new detailed model led to a closer prediction of the reported power change. The detailed recirculation loop model can provide more reliable boundary condition data to a CFD models for studies of, for example, flow induced vibration, wear, and crack initiation.

  10. Mathematical Modelling of Leachate Production from Waste Contained Site

    Directory of Open Access Journals (Sweden)

    Ojolo S. Joshua

    2012-07-01

    Full Text Available In this work, mathematical models of leachate production from Waste Contained Site (WCS was developed and validated using the existing experimental data with aid of MATLAB, 2007a. When the leachate generation potentials (Lo were 100m3, 80m3 and 50m3, the maximum amount of leachate generated were about 2920m3, 2338m3 and 1461m3 for about 130 days respectively. It was noted that as the leachate percolates through a selected distance, the concentration keeps decreasing for one-dimensional flow in all the cases considered. Decreasing in concentration continues until a point was reached when the concentration was almost zero and later constant. The effects of diffusivity, amount of organic content present within the waste and gravity, as cases, were also considered in various occasions during the percolation. Comparison of their effects was also taken into account. In case of gravity at constant diffusivity, decrease in concentration was not rapid but gradually while much organic content in the waste caused the rate of leachate production to be rapid; hence, giving rise to a sharp sloped curve. It can be concluded that gravity influences the rate of change in the concentration of the leachate generation as the leachate percolate downward to the underground water. When the diffusivity and gravity are put into consideration, the concentration of the leachate decreases gradually and slowly.

  11. BIOLOGICAL TREATMENT OF LEACHATE FROM A SUPERFUND SITE

    Science.gov (United States)

    Studies have heen completed on treating a leachate from New Lyme, Ohio. The leachate was transported to Cincinnati, Ohio, where a pilot-sized rotating biological contactor (RBC) was used for a treatment evaluation. he biomass was developed on the ARC discs with primary effluent f...

  12. Groundwater and Leachate Monitoring and Sampling at ERDF, CY 2009

    Energy Technology Data Exchange (ETDEWEB)

    R.L. Weiss, B.L. Lawrence, D.W. Woolery

    2010-07-08

    This document reports the findings of the groundwater and leachate monitoring and sampling at the Environmental restoration Disposal Facility for calendar year 2009. The purpose of this annual monitoring report is to evaluate the conditions of and identify trends for groundwater beneath the ERDF and report leachate results in fulfillment of the requirements specified in the ERDF ROD and the ERDF Amended ROD.

  13. Organic matter and concentrated nitrogen removal by shortcut nitrification and denitrification from mature municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-jun; PENG Yong-zhen; WANG Shu-ying; ZHENG Shu-wen; GUO Jin

    2007-01-01

    An UASB+Anoxic/Oxic (A/O) system was introduced to treat a mature landfill leachate with low carbon-to-nitrogen ratio and high ammonia concentration. To make the best use of the biodegradable COD in the leachate, the denitrification of NOx-N in the recirculation effluent from the clarifier was carried out in the UASB. The results showed that most biodegradable organic matters were removed by the denitrification in the UASB. The NH4+-N loading rate (ALR) of A/O reactor and operational temperature was 0.28-0.60 kg NH4+-N/(m3·d) and 17-29℃ during experimental period, respectively. The short-cut nitrification with nitrite accumulation efficiency of 90%-99% was stabilized during the whole experiment. The NH4+-N removal efficiency varied between 90% and 100%. When ALR was less than 0.45 kg NH4+-N/(m3·d), the NH4+-N removal efficiency was more than 98%. With the influent NH4+-N of 1200-1800 mg/L, the effluent NH4+-N was less than 15 mg/L. The shortcut nitrification and denitrification can save 40% carbon source, with a highly efficient denitrification taking place in the UASB. When the ratio of the feed COD to feed NH4+-N was only 2-3, the total inorganic nitrogen (TIN) removal efficiency attained 67%-80%. Besides, the sludge samples from A/O reactor were analyzed using FISH. The FISH analysis revealed that ammonia oxidation bacteria (AOB) accounted for 4% of the total eubacterial population, whereas nitrite oxidation bacteria (NOB) accounted only for 0.2% of the total eubacterial population.

  14. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

    2015-07-15

    Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  15. Partial nitrification for nitrogen removal from sanitary landfill leachate.

    Science.gov (United States)

    Spagni, Alessandro; Psaila, Giuliana; Rizzo, Andrea

    2014-09-19

    Biological nitrogen removal using nitrite as a shortcut has recently been proposed for the treatment of high strength landfill leachate. The aim of this study was to assess the application of the SHARON (Single reactor High activity Ammonium Removal Over Nitrite) process for the partial nitrification of leachate generated in old landfills. Particular attention was given to the start-up phase of the process. This study demonstrated that partial nitrification can be obtained when treating raw leachate after biomass acclimation. Only a fraction (50-70%) of the ammonia present in the leachate can be oxidised due to a limited amount of alkalinity available. Stable nitritation was obtained by applying a hydraulic retention time (HRT) of 4-5 d, which is higher than the values proposed for the effluent of anaerobic digesters. This higher HRT could probably be allowed by the high concentration of free ammonia present in the leachate, which could severely inhibit the growth of nitrite-oxidising bacteria.

  16. Assessment of landfill leachate toxicity reduction after biological treatment.

    Science.gov (United States)

    Jemec, Anita; Tišler, Tatjana; Zgajnar-Gotvajn, Andreja

    2012-02-01

    In the present article, the efficiency of biological treatment of landfill leachates was evaluated by implementation of physicochemical characterisation and a complex toxicity assessment. An array of toxicity tests using bacterium Vibrio fischeri, alga Desmodesmus subspicatus, crustacean Daphnia magna, and embryo of fish Danio rerio, as well as unconventional methods using biochemical biomarkers (protein content, enzymes cholinesterase, and glutathione-S-transferase), were employed. Toxicity of leachates varied depending on the season of collection in relation to their different physicochemical characteristics. Uncommon effects of leachates on organisms, such as hormetic-like increases of algal growth and reproduction of daphnids, were identified. New approaches using the activities of enzymes were found unsuitable for routine hazard assessment of leachates. Although physicochemical parameters and toxicity decreased significantly after biological treatment, the effluents did not meet the demands of the current Slovenian legislation; thus, the existing biological treatment was found inappropriate. The development of advanced treatment techniques for landfill leachates is thus encouraged.

  17. Removal of organic micro-pollutants from solid waste landfill leachate in membrane bioreactor operated without excess sludge discharge.

    Science.gov (United States)

    Boonyaroj, V; Chiemchaisri, C; Chiemchaisri, W; Yamamoto, K

    2012-01-01

    Two-stage membrane bioreactor (MBR) system was applied to the treatment of landfill leachate from a solid waste disposal site in Thailand. The first stage anoxic reactor was equipped with an inclined tube module for sludge separation. It was followed by an aerobic stage with a hollow fiber membrane module for solid liquid separation. Mixed liquor sludge from the aerobic reactor was re-circulated back to anoxic reactor in order to maintain constant mixed liquor suspended solids (MLSS) concentration in the aerobic reactor. The removal of micro-pollutants from landfill leachate along the treatment period of 300 days was monitored. The results indicated that two-stage MBRs could remove biochemical oxygen demand (BOD), chemical oxygen demand (COD) and NH(4)(+) by 97, 87 and 91% at steady operating condition. Meanwhile organic micro-pollutant removals were 50-76%. The removal efficiencies varied according to the hydrophobic characteristic of compounds but they were improved during long-term MBR operation without sludge discharge.

  18. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    YE ZhengFang; YU HongYan; WEN LiLi; NI JinRen

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl's method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L-1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L-1 and NH3 over 150 mg·L-1, At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  19. Treatment of landfill leachate by immobilized microorganisms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper focuses on the outcome and the main performance of the immobilized microbial that treats landfill leachate. Based on the analysis of COD and ammonia-nitrogen of the influent and effluent, research was done on the high removal efficiency of COD and ammonium nitrogen by immobilized microbial. The leachate composition was analyzed qualitatively using GC-MS before and after being treated. Biological loading of efficient microbial flora on the carrier was measured by Kjeldahl’s method. Finally, the patterns of immobilized microbe were observed through scanning electron microscopy (SEM). The results showed that in immobilized microorganisms system, the efficiencies of COD and nitrogen were 98.3% and 99.9%, respectively. There was a great reduction of organic components in effluent. When the immobilized biomass on the carrier was 38 g·L?1 (H2O), the filamentous microorganism was highly developed. There was no inhibitory effect on the nitrobacteria and nitrococcus, when ammonia was over 200 mg·L?1 and NH3 over 150 mg·L?1. At a high organic loading, it still had good nitrification. This paper also compares the performance of immobilized microbial with free microbial under the same condition. The immobilized microbial technology demonstrated better than the latter in all aspects.

  20. Modeling and simulation of the bioprocess with recirculation

    Directory of Open Access Journals (Sweden)

    Žerajić Stanko

    2007-01-01

    Full Text Available The bioprocess models with recirculation present an integration of the model of continuous bioreaction system and the model of separation system. The reaction bioprocess is integrated with separation the biomass, formed product, no consumed substrate or inhibitory substance. In this paper the simulation model of recirculation bioprocess was developed, which may be applied for increasing the biomass productivity and product biosynthesis increasing the conversion of a substrate-to-product, mixing efficiency and secondary C02 separation. The goal of the work is optimal bioprocess configuration, which is determined by simulation optimization. The optimal hemostat state was used as referent. Step-by-step simulation method is necessary because the initial bioprocess state is changing with recirculation in each step. The simulation experiment confirms that at the recirculation ratio a. = 0.275 and the concentration factor C = 4 the maximum glucose conversion to ethanol and at a dilution rate ten times larger.

  1. Engine with pulse-suppressed dedicated exhaust gas recirculation

    Science.gov (United States)

    Keating, Edward J.; Baker, Rodney E.

    2016-06-07

    An engine assembly includes an intake assembly, a spark-ignited internal combustion engine, and an exhaust assembly. The intake assembly includes a charge air cooler disposed between an exhaust gas recirculation (EGR) mixer and a backpressure valve. The charge air cooler has both an inlet and an outlet, and the back pressure valve is configured to maintain a minimum pressure difference between the inlet of the charge air cooler and an outlet of the backpressure valve. A dedicated exhaust gas recirculation system is provided in fluid communication with at least one cylinder and with the EGR mixer. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the at least one cylinder to the EGR mixer for recirculation back to the engine.

  2. A closed recirculated sea-water system

    Science.gov (United States)

    1967-01-01

    Study of a virus disease in the chinook salmon (Oncorhynchus tshawytscha) necessitated the use of a marine environment to study the long range effects of the disease and to complete the life cycle of its etiologic agent. A closed recirculated sea-water system was designed for use under experimental laboratory conditions so that controlled studies of the disease could be made. As others may wish to do marine environment studies in the laboratory, the design and operation of our system are presented. Other systems currently in use have been described by Chin (1959), DeWitt and Salo (1960), McCrimmon and Berst (1966), and the authors of collected papers edited by Clark and Clark (1964). Preparatory to the design and construction of the system in use in this laboratory, visits were made to marine systems in use at the University of Washington's College of Fisheries, Seattle, -washington, and Friday Harbor Laboratory, San Juan Island, Washington; the Washington State Department of Fisheries' Point whitney Shellfish Laboratory, Brinnon, Washington; Humboldt State College, Arcata, California; and the Steinhart Aquarium of the California Academy of Science, San Francisco, California.

  3. Modeling of TAN in recirculating aquaculture systems by AQUASIM

    DEFF Research Database (Denmark)

    Arvin, Erik; Pedersen, Lars-Flemming

    2011-01-01

    Modeling of total ammonium nitrogen (TAN) in recirculating aquaculture systems (RAS) contribute to identifying and quantifying the most important processes and their relative contribution to removal of TAN. AQUASIM is a flexible modular simulation system for water quality in natural and technical...... systems developed by EAWAG (Reichert, 1994). AQUASIM allows simulating complex biological, chemical and physical processes in standardized hydraulic systems. We used AQUASIM to model the steady state TAN concentrations in 12 experimental recirculating aquaculture systems (RAS) operated by DTU AQUA...

  4. Field survey of enteric viruses in solid waste landfill leachates.

    Science.gov (United States)

    Sobsey, M D

    1978-09-01

    Because municipal solid waste may contain fecal material from a variety of sources, there is concern that the leachate discharged from some solid waste landfills may contain enteric pathogens, including enteric viruses. In this study, 22 leachate samples from 21 different landfills in the United States and Canada were examined for enteric viruses. The sites represented a broad range of conditions for solid waste landfills and the leachate samples ranged from 10.3 to 18 liters in volume. Enteric viruses were found in only one of the 22 leachate samples examined. Two viruses, identified as poliovirus types 1 and 3, were found in an 11.8 liter sample obtained from a site where solid waste landfill practice was deficient. The low levels of enteric viruses detected in field samples of raw leachate and the opportunities for further reductions in the virus concentration of leachates by such processes as thermal inactivation, removal by soil and dilution in ground and surface waters, suggest that leachates from properly operated solid waste landfills do not constitute an environmental or public health hazard due to enteric viruses.

  5. Selection оf Parameters for System of Diesel Engine Exhaust Gas Recirculation

    Directory of Open Access Journals (Sweden)

    G. M. Kukharionok

    2014-01-01

    Full Text Available The paper presents research results of various methods for recirculation of diesel engine exhaust gases. An influence of recirculation parameters on economic and ecological diesel engine characteristics has been evaluated in the paper. The paper considers an influence of turbocharger configuration on the intensity of gas recirculation. Specific features of the recirculation system operation in dynamic modes have been shown in the paper. The paper provides recommendations for selection of a diesel engine exhaust gas recirculation system.

  6. Possibility of Zero Discharge of Waste Leachate from Domestic Waste Incineration Plants%浅析生活垃圾焚烧厂渗沥液污水零排放可能性

    Institute of Scientific and Technical Information of China (English)

    季华文

    2013-01-01

    分析了目前生活垃圾焚烧厂渗沥液主要处理现状,介绍了膜浓缩液的回灌、焚烧、蒸发、高级氧化及回用等主要处理方法;得出一旦解决膜浓缩液的处置问题,渗沥液污水零排放是可能的.%The main status of leachate treatment in domestic waste incineration plants was analyzed. Main treatment methods of the membrane concentrated solution were introduced, including recirculation, incineration, evaporation, advanced oxidation, and reuse. Once the problem of membrane concentrated solution treatment has been solved, the zero discharge of waste leachate is possible.

  7. Biodegradability enhancement of a leachate after biological lagooning using a solar driven photo-Fenton reaction, and further combination with an activated sludge biological process, at pre-industrial scale.

    Science.gov (United States)

    Silva, Tânia F C V; Fonseca, Amélia; Saraiva, Isabel; Vilar, Vítor J P; Boaventura, Rui A R

    2013-06-15

    This work proposes an integrated leachate treatment strategy, combining a solar photo-Fenton reaction, to enhance the biodegradability of the leachate from an aerated lagoon, with an activated sludge process, under aerobic and anoxic conditions, to achieve COD target values and nitrogen content according to the legislation. The efficiency and performance of the photo-Fenton reaction, concerning a sludge removal step after acidification, defining the optimum phototreatment time to reach a biodegradable wastewater that can be further oxidized in a biological reactor and, activation sludge biological process, defining the nitrification and denitrification reaction rates, alkalinity balance and methanol dose necessary as external carbon source, was evaluated in the integrated system at a scale close to industrial. The pre-industrial plant presents a photocatalytic system with 39.52 m(2) of compound parabolic collectors (CPCs) and 2 m(3) recirculation tank and, an activated sludge biological reactor with 3 m(3) capacity. Leachate biodegradability enhancement by means of a solar driven photo-Fenton process was evaluated using direct biodegradability tests, as Zahn-Wellens method, and indirect measure according to average oxidation state (AOS), low molecular carboxylic acids content (fast biodegradable character) and humic substances (recalcitrant character) concentration. Due to high variability of leachate composition, UV absorbance on-line measurement was established as a useful parameter for photo-Fenton reaction control. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. LCA and economic evaluation of landfill leachate and gas technologies.

    Science.gov (United States)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna; Stensøe, Steen; Christensen, Thomas H

    2011-07-01

    Landfills receiving a mix of waste, including organics, have developed dramatically over the last 3-4 decades; from open dumps to engineered facilities with extensive controls on leachate and gas. The conventional municipal landfill will in most climates produce a highly contaminated leachate and a significant amount of landfill gas. Leachate controls may include bottom liners and leachate collection systems as well as leachate treatment prior to discharge to surface water. Gas controls may include oxidizing top covers, gas collection systems with flares or gas utilization systems for production of electricity and heat. The importance of leachate and gas control measures in reducing the overall environmental impact from a conventional landfill was assessed by life-cycle-assessment (LCA). The direct cost for the measures were also estimated providing a basis for assessing which measures are the most cost-effective in reducing the impact from a conventional landfill. This was done by modeling landfills ranging from a simple open dump to highly engineered conventional landfills with energy recovery in form of heat or electricity. The modeling was done in the waste LCA model EASEWASTE. The results showed drastic improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to -0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE). For the toxic and spoiled groundwater impact categories the trend is not as clear. The reason for this was that the load to the environment shifted as more technologies were used. For the dump landfill the main impacts were impacts for spoiled groundwater due to lack of leachate collection, 2.3 PE down to 0.4 PE when leachate is collected. However, at the same time, leachate collection causes a slight increase in eco-toxicity and human toxicity via water (0.007 E to 0

  9. Supercritical water oxidation of landfill leachate.

    Science.gov (United States)

    Wang, Shuzhong; Guo, Yang; Chen, Chongming; Zhang, Jie; Gong, Yanmeng; Wang, Yuzhen

    2011-01-01

    In this paper, ammonia as an important ingredient in landfill leachate was mainly studied. Based on Peng-Robinson formulations and Gibbs free energy minimization method, the estimation of equilibrium composition and thermodynamic analysis for supercritical water oxidation of ammonia (SCWO) was made. As equilibrium is reached, ammonia could be totally oxidized in SCW. N(2) is the main product, and the formation of NO(2) and NO could be neglected. The investigation on SCWO of landfill leachate was conducted in a batch reactor at temperature of 380-500 °C, reaction time of 50-300s and pressure of 25 MPa. The effect of reaction parameters such as oxidant equivalent ratio, reaction time and temperature were investigated. The results showed that COD and NH(3) conversion improved as temperature, reaction time and oxygen excess increased. Compared to organics, NH(3) is a refractory compound in supercritical water. The conversion of COD and NH(3) were higher in the presence of MnO(2) than that without catalyst. The interaction between reaction temperature and time was analyzed by using response surface method (RSM) and the results showed that its influence on the NH(3) conversion was relatively insignificant in the case without catalyst. A global power-law rate expression was regressed from experimental data to estimate the reaction rate of NH(3). The activation energy with and without catalyst for NH(3) oxidation were 107.07 ± 8.57 kJ/mol and 83.22 ± 15.62 kJ/mol, respectively.

  10. Field survey of enteric viruses in solid waste landfill leachates

    National Research Council Canada - National Science Library

    Sobsey, M D

    1978-01-01

    Because municipal solid waste may contain fecal material from a variety of sources, there is concern that the leachate discharged from some solid waste landfills may contain enteric pathogens, including enteric viruses...

  11. Adsorption of heavy metal from landfill leachate by wasted biosolids

    African Journals Online (AJOL)

    GREGORY

    2011-12-16

    Dec 16, 2011 ... Key words: Adsorption, biomass waste, heavy metal, synthetic water, leachate. INTRODUCTION ... Gadd, 1993; White et al., 1997). There is also ..... The performance of natural clay as a barrier to the diffusion of municipal ...

  12. levels of some physiochemical parameters in leachates from open ...

    African Journals Online (AJOL)

    Department of Pure and Industrial Chemistry, Bayero University Kano .... waste water treated and directive (European Union. 2000), there has ... Sample Treatment ... biological oxygen demand determination of the leachate sample in mg/l was.

  13. Groundwater and Leachate Monitoring and Sampling at ERDF, CY 2008

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Weiss; D. W. Woolery

    2009-09-03

    The purpose of this annual monitoring report is to evaluate the conditions of and identify trends for groundwater beneath the ERDF, to report leachate results in fulfillment of the requirements specified in the ERDF ROD and the ERDF Amended ROD.

  14. Biological Treatment of Leachate using Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    WDMC Perera

    2014-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE TA Abstract   In Sri Lanka municipal solid waste is generally disposed in poorly managed open dumps which lack liner systems and leachate collection systems. Rain water percolates through the waste layers to produce leachate which drains in to ground water and finally to nearby water bodies, degrading the quality of water. Leachate thus has become a major environmental concern in municipal waste management and treatment of leachate is a major challenge for the existing and proposed landfill sites.   The study was conducted to assess the feasibility of the usage of the Sequencing Batch Reactor in the treatment of the landfill leachate up to the proposed levels in the draft report of “Proposed Sri Lankan standard for landfill leachate to be disposed to the inland waters". Leachate collected from the open dumpsite at Meethotamulla, Western Province, Sri Lanka was used for leachate characterization.   SBR was constructed with a 10-liter working volume operated in an 18 hour cycle mode and each cycle consists of 15hours of aerobic, 2h settle and 0.5 h of fill/decant stages. The Dissolved Oxygen level within the SBR was maintained at 2 mg/l through the aerobic stage. Infeed was diluted with water during the acclimatization period and a leachate to water ratio of 55:45 was maintained. The removal efficiencies for different parameters were; COD (90.5%, BOD (92.6%, TS (92.1%, Conductivity (83.9%, Alkalinity (97.4%, Hardness (82.2%, Mg (80.5%, Fe (94.2%, Zn (63.4%, Cr (31.69%, Pb (99.6%, Sulphate (98.9%, and Phosphorus (71.4% respectively. In addition Ni and Cd were removed completely during a single SBR cycle. Thus the dilution of leachate in the dumpsites using municipal wastewater, groundwater or rainwater was identified as the most cost effective dilution methods. The effluent from the Sequencing batch reactor is proposed to be further treated using a constructed wetland before releasing to surface water.

  15. Ammonia nitrogen desorption from sanitary landfill leachate in filling towers

    OpenAIRE

    Leite,Valderi D.; Barros,Aldre J. M.; Lopes,Wilton S.; Sousa,José T. de

    2014-01-01

    Sanitary landfill leachates present high concentrations of carbonaceous and nitrogenous materials. The crucial point is that carbonaceous materials are of difficult biodegradation, what compromises the performance of biological treatment processes, while nitrogenous materials, such as ammonia nitrogen, probably preclude the use of biological treatments. Therefore, the aim of this work was to study the desorption process of ammonia nitrogen from sanitary landfill leachate in filling towers. De...

  16. Characterization and toxicological evaluation of leachate from closed sanitary landfill.

    Science.gov (United States)

    Emenike, Chijioke U; Fauziah, Shahul H; Agamuthu, P

    2012-09-01

    Landfilling is a major option in waste management hierarchy in developing nations. It generates leachate, which has the potential of polluting watercourses. This study analysed the physico-chemical components of leachate from a closed sanitary landfill in Malaysia, in relation to evaluating the toxicological impact on fish species namely Pangasius sutchi S., 1878 and Clarias batrachus L., 1758. The leachate samples were taken from Air Hitam Sanitary Landfill (AHSL) and the static method of acute toxicity testing was experimented on both fish species at different leachate concentrations. Each fish had an average of 1.3 ± 0.2 g wet weight and length of 5.0 ± 0.1 cm. Histology of the fishes was examined by analysing the gills of the response (dead) group, using the Harris haemtoxylin and eosin (H&E) method. Finneys' Probit method was utilized as a statistical tool to evaluate the data from the fish test. The physico-chemical analysis of the leachate recorded pH 8.2 ± 0.3, biochemical oxygen demand 3500 ± 125 mg L(-1), COD 10 234 ± 175 mg L(-1), ammonical nitrogen of 880 ± 74 mg L(-1), benzene 0.22 ± 0.1 mg L(-1) and toluene 1.2 ± 0.4 mg L(-1). The 50% lethality concentration (LC(50)) values calculated after 96 h exposure were 3.2% (v/v) and 5.9% (v/v) of raw leachate on P. sutchi and C. batrachus, respectively. The H&E staining showed denaturation of the nucleus and cytoplasm of the gills of the response groups. Leachate from the sanitary landfill was toxic to both fish species. The P. sutchi and C. batrachus may be used as indicator organisms for leachate pollution in water.

  17. Sulphur recirculation for reduced boiler corrosion; Minskad pannkorrosion med svavelrecirkulation

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven; Karlsson, Martin (Goetaverken Miljoe AB, Goeteborg (Sweden)); Blomqvist, Evalena; Baefver, Linda; Claesson, Frida; Davidsson, Kent (SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden)); Froitzheim, Jan; Pettersson, Jesper; Steenari, Britt-Marie (Chalmers Tekniska Hoegskola, Oorganisk miljoekemi, Goeteborg (Sweden))

    2010-03-15

    Sulphur recirculation is a new technology for reducing boiler corrosion and dioxin formation, which was demonstrated in full-scale tests performed at the Renova Waste to Energy plant at Saevenaes in Goeteborg (Sweden). Sulphur is recirculated from the flue gas cleaning back to the boiler, which reduces the chloride content of the deposits, which in turn reduces boiler corrosion and dioxin formation. Sulphur dioxide was separated from the flue gas in a wet scrubber by adding hydrogen peroxide, producing sulphuric acid. The sulphuric acid was injected into the furnace using nozzles with atomization air, surrounded by recirculated flue gas for improved mixing. By recirculating the sulphur, the sulphur dioxide concentration was increased in the boiler. Each sulphur atom passed the boiler several times and no external sulphur had to be added. Dioxin, ash, deposits and particle samplings together with 1000 h corrosion probe measurements were performed for normal operation (reference) and with sulphur recirculation respectively. During spring 2009, reference measurements were made and the recirculation system was installed and tested. During autumn 2009, a long term test with sulphur recirculation was made. An SO{sub 2} concentration of approximately 800 mg/m3 (n, d.g.) was maintained in the boiler by the system except during a period of extremely low sulphur content in the waste. The sulphur dioxide stack concentrations have been far below the emission limit. Sulphuric acid dew point measurements have shown that the sulphuric acid dosage did not lead to elevated SO{sub 3} concentrations, which may otherwise lead to low temperature corrosion. The chlorine content of both fly ash and boiler ash decreased and the sulphur content increased during the sulphur recirculation tests. The molar chlorine/sulphur ratio (Cl/S) decreased by two thirds in the fly ash as well as in the boiler ash, except for one sample. With sulphur recirculation in operation, the deposit growth was

  18. Leachate from microplastics impairs larval development in brown mussels.

    Science.gov (United States)

    Gandara E Silva, Pablo Pena; Nobre, Caio Rodrigues; Resaffe, Pryscila; Pereira, Camilo Dias Seabra; Gusmão, Felipe

    2016-12-01

    Microplastic debris is a pervasive type of contaminant in marine ecosystems, being considered a major threat to marine biota. One of the problems of microplastics is that they can adsorb contaminants in extremely high concentrations. When released from the particle, these contaminants have the potential to cause toxic effects in the biota. So far, reports of toxic effects are mostly linked with the direct exposure of organisms through ingestion of contaminated microplastics. There is little information on the toxicity of leachates from microplastics to marine organisms. In this study, we conducted experiments to evaluate the toxicity of leachates from virgin and beached plastic pellets to embryo development of the brown mussel (Perna perna). We compared the efficiency of two test procedures, and evaluated the toxicity of beached pellets collected in a coastal marine protected area. We observed that mussel embryo is sensitive to leachate from both virgin and beached pellets. However, the toxicity of the leachate from beached pellets was much higher than that of virgin pellets. We suggest contaminants adsorbed onto the surface of beached pellets were responsible for the high toxicity of leachate from beached pellets, while the toxicity of leachate from virgin pellets was mainly due to plastic additives. Our results suggest microplastic debris may be harmful even if ingestion is not the only or main pathway of interaction of marine organisms with contaminated plastic debris.

  19. Impact of leachate composition on the advanced oxidation treatment.

    Science.gov (United States)

    Oulego, Paula; Collado, Sergio; Laca, Adriana; Díaz, Mario

    2016-01-01

    Advanced oxidation processes (AOPs) are gaining importance as an alternative to the biological or physicochemical treatments for the management of leachates. In this work, it has been studied the effect of the characteristics of the leachate (content in humic acids, landfill age and degree of stabilization) on the wet oxidation process and final quality of the treated effluent. A high concentration of humic acids in the leachate had a positive effect on the COD removal because this fraction is more easily oxidizable. Additionally, it has been demonstrated that the simultaneous presence of humic acid and the intermediates generated during the oxidation process improved the degradation of this acid, since such intermediates are stronger initiators of free radicals than the humic acid itself. Similar values of COD removals (49% and 51%) and biodegradability indices (0.30 and 0.35) were observed, after 8 h of wet oxidation, for the stabilised leachate (biologically pretreated) and the raw one, respectively. Nevertheless, final colour removal was much higher for the stabilised leachate, achieving values up to 91%, whereas for the raw one only 56% removal was attained for the same reaction time. Besides, wet oxidation treatment was more efficient for the young leachate than for the old one, with final COD conversions of 60% and 37%, respectively. Eventually, a triangular "three-lump" kinetic model, which considered direct oxidation to CO2 and partial oxidation through intermediate compounds, was here proposed.

  20. Attenuation of Landfill Leachate In Unsaturated Sandstone

    Science.gov (United States)

    Butler, A. P.; Brook, C.; Godley, A.; Lewin, K.; Young, C. P.

    Landfill leachate emanating from old "dilute and disperse" sites represents a potential (and in many cases actual) threat to the integrity of groundwater. Indeed, this concern has been included in EU legislation (80/86/EEC), where key contaminants (e.g. ammonia, various toxic organic compounds and heavy metals) are explicitly highlighted in terms of their impact on groundwater. In the UK, whilst there are a substantial number of unlined landfills sited on major aquifers, many of these are in locations where there is a substantial unsaturated zone. Thus, there exists the opportunity for the modification and attenuation of contaminants prior to it encountering the water table. An understanding of likely changes in leachate content and concentrations at such sites will enable a more comprehensive assessment of the potential risks and liabilities posed by such sites to be evaluated. The Burntstump landfill, situated 8 km north of Nottingham (UK), is sited on an outcrop of Sherwood sandstone. The fine friable sand has been quarried since the 1960s and the excavated volume used to store municipal waste. Filling at the site commenced in the mid 1970s and originally was unlined. In 1978 the first of what was to become a series of boreholes was installed within an area of roughly 5 m radius over one of the original waste cells. Cores of the waste and underlying sandstone were extracted and analysed for a range of physical and chemical parameters. The most recent set of analyses were obtained in 2000. The series of investigations therefore provide an important record of leachate migration and modification through the unsaturated zone for over twenty years. The progression of the leachate front is clearly delineated by the chloride concentration profile with an average velocity of around 1.6 m.yr-1. Combining this value with an average (and reasonably uniform) measured moisture content of about 7% gives a mean inter-granular specific discharge of 110 mm.yr-1. An interesting

  1. Acceleration schedules for a recirculating heavy-ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, W.M.; Grote, D.P.

    2002-05-01

    Recent advances in solid-state switches have made it feasible to design programmable, high-repetition-rate pulsers for induction accelerators. These switches could lower the cost of recirculating induction accelerators, such as the ''small recirculator'' at Lawrence Livermore National Laboratory (LLNL), by substantially reducing the number of induction modules. Numerical work is reported here to determine what effects the use of fewer pulsers at higher voltage would have on the beam quality of the LLNL small recirculator. Lattices with different numbers of pulsers are examined using the fluid/envelope code CIRCE, and several schedules for acceleration and compression are compared for each configuration. For selected schedules, the phase-space dynamics is also studied using the particle-in-cell code WARP3d.

  2. Particle surface area and bacterial activity in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo

    2017-01-01

    Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation......-up water; corresponding to 0.32 m3 make-up water kg−1 feed). This was likely due to the accumulation of dissolved nutrients sustaining free-living bacterial populations, and/or accumulation of suspended colloids and fine particles less than 5 μm in diameter, which were not characterized in the study...

  3. Analysis of Errors Involved in the Estimation of Leachate Pollution Index Due to Nonavailability of Leachate Parameter

    Directory of Open Access Journals (Sweden)

    Islam M. Rafizul

    2012-01-01

    Full Text Available An important part of maintaining a solid waste landfill is managing the leachate through proper treatment to prevent pollution into the surrounding ground and surface water. Any assessment of potential impact of a landfill on groundwater quality requires consideration of the component of leachate most likely to cause an envionental impact as well as the source of concentration of those components. Leachate pollution index (LPI is an environmental index used to quantify and compare the leachate contamination potential of solid waste landfill. This index is based on concentration of 18 pollutants in leachate and their corresponding significance. That means, for calculating the LPI of a landfill, concentration of these 18 parameters are to be known. However, sometimes the data for all the 18 pollutants included in the LPI may not be available to calculate the LPI. In this study, the possible errors involved in calculating the LPI due to nonavailability of data are reported by the author. The leachate characteristic data for solid waste landfill at Chittagong in Bangladesh have been used to estimate these errors. Based on this study, it can be concluded that the errors may be high if the data for the pollutants having significantly high or low concentration are not available. However, LPI can be reported with a marginal error if the concentrations of the nonavailable pollutants are not completely biased.

  4. Kinetics of Organic Matter Biodegradation in Leachate from Tobacco Waste

    Directory of Open Access Journals (Sweden)

    Briški, F.

    2012-09-01

    Full Text Available Treatment of wastes and leachate evolved in landfills is today an imperative due to rigorous environmental protection legislation. In this work, biodegradation of the organic fraction in tobaccowaste leachate was studied. Experiments were carried out in a batch reactor at initial concentra tion of activated sludge of 3.03 g dm–3 and different initial concentrations of organic matter in leachate, expressed as COD, which ranged from 0.5 to 3.0 g dm–3 . The working volume of the reactor (Fig. 1 was 7 dm3 within the cylindrical porous liner and it was filled with the suspension of leachate and activated sludge . The liner was designed such that it did not allow activated sludge to pass through. Continuous up-flow aeration was provided by a membrane pump. The temperature during the biodegradation process was 23 ± 2 °C. Dissolved oxygen, pH and temperature in reactor were monitored continuously by probes connected to a remote meter. Toxicity of leachate was performed by toxicity test using marine bacteria Vibrio fischeri before starting with the biodegradation in the batch reactor. The obtained results showed that effective concentration of leachate is EC 50 = 1.6 g dm–3 and toxicity impact index is TII50 = 9.99, meaning that untreated leachate must not be discharged into the environment before treatment. The results of the biodegradation process of leachate in batch reactor are presented in Table 1 and Fig. 2. The ratio γXv/γX was almost constant throughout the experiments and ranged from 0.69 do 0.73. This implies that the concentration of biomass remained unchanged during the experiments, and average yield was 5.26 %. The important kinetic and stoichiometric parameters required for performance of the biological removal process, namely the Y, Ks, Kd, and μmax were calculated from the batch experiments (Table 2. The experimental results of the influence of initial substrate concentrations on substrate degradation rate, and influence of

  5. The impact of tropical recirculation on polar composition

    Directory of Open Access Journals (Sweden)

    S. E. Strahan

    2009-01-01

    Full Text Available We derive the tropical modal age of air from an analysis of the water vapor tape recorder. We combine the observationally derived modal age with mean age of air from CO2 and SF6 to create diagnostics for the independent evaluation of the vertical transport rate and horizontal recirculation into the tropics between 16–32 km. These diagnostics are applied to two Global Modeling Initiative (GMI chemistry and transport model (CTM age tracer simulations to give new insights into the tropical transport characteristics of the meteorological fields from the GEOS4-GCM and the GEOS4-DAS. Both simulations are found to have modal ages that are in reasonable agreement with the empirically derived age (i.e., transit times over the entire altitude range. Both simulations show too little horizontal recirculation into the tropics above 22 km, with the GEOS4-DAS fields having greater recirculation. Using CH4 as a proxy for mean age, comparisons between HALOE and model CH4 in the Antarctic demonstrate how the strength of tropical recirculation affects polar composition in both CTM experiments. The better the tropical recirculation is simulated, the better the CH4 simulation is in the Antarctic. Mean age in the Antarctic lower stratosphere can be compromised by poor representation of tropical ascent, tropical recirculation, or vortex barrier strength. The connection between polar and tropical composition shown in this study demonstrates the importance of diagnosing each of these processes separately in order to verify the adequate representation of the processes contributing to polar composition in models.

  6. The impact of tropical recirculation on polar composition

    Directory of Open Access Journals (Sweden)

    S. E. Strahan

    2009-04-01

    Full Text Available We derive the tropical modal age of air from an analysis of the water vapor tape recorder. We combine the observationally derived modal age with mean age of air from CO2 and SF6 to create diagnostics for the independent evaluation of the vertical transport rate and horizontal recirculation into the tropics between 16–32 km. These diagnostics are applied to two Global Modeling Initiative (GMI chemistry and transport model (CTM age tracer simulations to give new insights into the tropical transport characteristics of the meteorological fields from the GEOS4-GCM and the GEOS4-DAS. Both simulations are found to have modal ages that are in reasonable agreement with the empirically derived age (i.e., transit times over the entire altitude range. Both simulations show too little horizontal recirculation into the tropics above 22 km, with the GEOS4-DAS fields having greater recirculation. Using CH4 as a proxy for mean age, comparisons between HALOE and model CH4 in the Antarctic demonstrate how the strength of tropical recirculation affects polar composition in both CTM experiments. Better tropical recirculation tends to improve the CH4 simulation in the Antarctic. However, mean age in the Antarctic lower stratosphere can be compromised by poor representation of tropical ascent, tropical recirculation, or vortex barrier strength. The connection between polar and tropical composition shown in this study demonstrates the importance of diagnosing each of these processes separately in order to verify the adequate representation of the processes contributing to polar composition in models.

  7. Use Recirculator "SALO" in the Mode of the Neutron Source

    CERN Document Server

    Guk, Ivan S; Dovbnya, Anatoly N; Kononenko, Stanislav; Peev, Fedor; Tarasenko, Alexander; Van der Wiel, Marnix

    2005-01-01

    The opportunity of use developed in NSC KIPT recirculator SALO* with superconducting accelerating structure TESLA for reception of intensive neutron streams surveyed. As an injector it is supposed to use RF-gun with superconducting accelerating structure. An electron beam with the peak energy 130 ??? is transported on a target located apart of 100 m from recirculator. System of the focusing are designed allowing to gain on a target the required density of a beam. Tolerances on precision of an alignment of magnetooptical devices are calculated.

  8. Reuse & Recirculation of Filter Backwash Water of Water Treatment Water

    Directory of Open Access Journals (Sweden)

    Mangesh L. Jibhakate

    2017-04-01

    Full Text Available Most of the water treatment plant, filtration is done by means of sand filtration process. Due to continuous filtration process, sand pores get clogged and decreases the efficiency. For mitigating such problem, reverse flow of water & air i.e. backwashing process is carried out. To carry out backwashing operation, 4% of treated water has been utilized and will result in muddy water known as backwash water. This backwash water is then discharged into a natural stream or storage tank near the plant for recirculation. The present study includes a trial for the reuse & recirculation of backwash water.

  9. Efficiency enhancement in gasoline reforming through the recirculation of reformate

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, J. [DaimlerChrysler AG, RBP/AS, 89081 Ulm (Germany); Sommer, M. [DaimlerChrysler AG, RTC/A, 70567 Stuttgart (Germany); Diezinger, S.; Trimis, D.; Durst, F. [FAU Erlangen-Nurnberg, LSTM, 91031 Erlangen (Germany)

    2006-03-21

    Fuel processors for on-board hydrogen production have to meet numerous technical demands. They should be efficient, compact and lightweight, capable of different loads and able to perform cold start ups. In this paper, the recirculation of reformate is proposed as a means of efficiency enhancement. Different system configurations based on this idea are introduced and simulated. The resulting effect on the system's efficiency, the water balance as well as the impact of recirculation on the system's volume and weight are discussed. (author)

  10. A recirculating cooling system for improved topical cardiac hypothermia.

    Science.gov (United States)

    Rosenfeldt, F L; Fambiatos, A; Pastoriza-Pinol, J; Stirling, G R

    1981-10-01

    A simple system is described that recirculates cooling fluid for topical cardiac hypothermia. This disposable system can produce a flow of 1,500 ml/min at 2 degrees to 4 degrees C. The recirculating cooler produced significantly lower myocardial temperatures than a conventional fluid-discard system in 22 patients having coronary operation. This system has been used as part of the technique of hypothermic cardioplegia in more than 600 patients. During various cardiac procedures, septal temperatures were maintained well below 20 degrees C for 60 minutes or more without the need to reinfuse the cardioplegic solution.

  11. Geophysical mapping of contaminant leachate around a reclaimed open dumpsite

    Directory of Open Access Journals (Sweden)

    W.O. Raji

    2017-07-01

    Full Text Available Very low frequency electromagnetic (VLF-EM, 2D Electrical Resistivity Profiling (2D ERP and Vertical Electrical Sounding (VES methods of geophysics were deployed to map the extent of leachate contamination in near-surface rocks around a popular reclaimed dumpsite in north central Nigeria. Two years after abandon and waste excavation; the dumpsite was converted to a residential area with over 80 houses under construction. Prior to waste dumping operation, clay-seal was installed at 2 m depth around the dumpsite to prevent leachate from the waste material flowing to the adjoining area. Results from VLF, 2D ERP, and VES show presence of leachate contamination in rocks and soil of the reclaimed dumpsite. Leachate has spread laterally up to a distance of about 1 km on the northern and southern parts of the dumpsite centre, and up to a depth of about 20 m. Compared to the results of similar survey in an area outside the dumpsite, leachate infiltration raised the conductivity signature of the rocks around the dumpsite by about 200%: from 7% to 22%. Both VLF-EM and 2D ERP show the presence of approximate north – south oriented structures/fracture characterised by high conductivity. VES results show the presence of four – five geo-electric layers. Important conclusions from the study are that (i leachate is still present in the rocks and soil of the reclaimed dumpsite two years after the abandonment and excavation of the waste materials, and (ii the clay seal installed around the dumpsite could not prevent leachate migration to the adjoining areas.

  12. Ion chromatographic analysis of oil shale leachates

    Energy Technology Data Exchange (ETDEWEB)

    Butler, N.L.

    1990-10-01

    In the present work an investigation of the use of ion chromatography to determine environmentally significant anions present in oil shale leachates was undertaken. Nadkarni et al. have used ion chromatography to separate and quantify halogen, sulfur and nitrogen species in oil shales after combustion in a Parr bomb. Potts and Potas used ion chromatography to monitor inorganic ions in cooling tower wastewater from coal gasification. Wallace and coworkers have used ion chromatography to determine anions encountered in retort wastewaters. The ions of interest in this work were the ions of sulfur oxides including sulfite (SO{sub 3}{sup 2{minus}}), sulfate (SO{sub 4}{sup 2{minus}}), thiosulfate (S{sub 2}O{sub 3}{sup 2{minus}}), dithionite (S{sub 2}O{sub 4}{sup 2{minus}}), dithionate (S{sub 2}O{sub 6}{sup 2{minus}}), peroxyodisulfate (S{sub 2}O{sub 8}{sup 2{minus}}), and tetrathionate (S{sub 4}O{sub 6}{sup 2{minus}}), and thiocyanate (SCN{sup {minus}}), sulfide (S{sup 2{minus}}) hydrosulfide (HS{sup {minus}}), cyanide (CN{sup {minus}}), thiocyanate (SCN{sup {minus}}), and cyanate (OCN{sup {minus}}). A literature search was completed and a leaching procedure developed. 15 refs., 6 figs., 1 tab.

  13. Impact of cigarette butt leachate on tidepool snails.

    Science.gov (United States)

    Booth, David J; Gribben, Paul; Parkinson, Kerryn

    2015-06-15

    In urban areas, cigarette butts are the most common discarded refuse articles. In marine intertidal zones, they often fall into tidepools. We tested how common intertidal molluscs were affected by butt leachate in a laboratory experiment, where snails were exposed to various leachate concentrations. Mortality was very high, with all species showing 100% mortality at the full leachate concentration (5 butts per litre and 2h soak time) after 8days. However, Austrocochlea porcata showed higher mortality than the other 2 species at lower concentrations (10%, 25%) which may affect the relative abundance of the 3 snails under different concentrations of leachate pollution. Also, sublethal effects of leachate on snail activity were observed, with greater activity of Nerita atramentosa than the other 2 species at higher concentrations, suggesting it is more resilient than the other 2 species. While human health concerns predominate with respect to smoking, we show strong lethal and sublethal (via behavioural modifications) impacts of discarded butts on intertidal organisms, with even closely-related taxa responding differently.

  14. Mutagenicity and genotoxicity of coal fly ash water leachate

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, R.; Mukherjee, A. [University of Calcutta, Calcutta (India). Dept. of Botany

    2009-03-15

    Fly ash is a by-product of coal-fired electricity generation plants. The prevalent practice of disposal is as slurry of ash and water to storage or ash ponds located near power stations. This has lain to waste thousands of hectares of land all over the world. Since leaching is often the cause of off-site contamination and pathway of introduction into the human environment, a study on the genotoxic effects of fly ash leachate is essential. Leachate prepared from the fly ash sample was analyzed for metal content, and tested for mutagenicity and genotoxicity. Analyses of metals show predominance of the metals - sodium, silicon, potassium, calcium, magnesium, iron, manganese, zinc, and sulphate. The Ames Salmonella mutagenicity assay, a short-term bacterial reverse mutation assay, was conducted on two-tester strains of Salmonella typhimurium strains TA97a and TA102. For genotoxicity, the alkaline version of comet assay on fly ash leachate was carried in vitro on human blood cells and in vivo on Nicotiana plants. The leachate was directly mutagenic and induced significantconcentration-dependent increases in DNA damage in whole blood cells, lymphocytes, and in Nicotiana plants. The comet parameters show increases in tail DNA percentage (%), tail length (mu m), and olive tail moment (arbitrary units). Our results indicate that leachate from fly ash dumpsites has the genotoxic potential and may lead to adverse effects on vegetation and on the health of exposed human populations.

  15. Toxic hazard and chemical analysis of leachates from furfurylated wood.

    Science.gov (United States)

    Pilgård, Annica; Treu, Andreas; van Zeeland, Albert N T; Gosselink, Richard J A; Westin, Mats

    2010-09-01

    The furfurylation process is an extensively investigated wood modification process. Furfuryl alcohol molecules penetrate into the wood cell wall and polymerize in situ. This results in a permanent swelling of the wood cell walls. It is unclear whether or not chemical bonds exist between the furfuryl alcohol polymer and the wood. In the present study, five different wood species were used, both hardwoods and softwoods. They were treated with three different furfurylation procedures and leached according to three different leaching methods. The present study shows that, in general, the leachates from furfurylated wood have low toxicity. It also shows that the choice of leaching method is decisive for the outcome of the toxicity results. Earlier studies have shown that leachates from wood treated with furfuryl alcohol prepolymers have higher toxicity to Vibrio fischeri than leachates from wood treated with furfuryl alcohol monomers. This is probably attributable to differences in leaching of chemical compounds. The present study shows that this difference in the toxicity most likely cannot be attributed to maleic acid, furan, furfural, furfuryl alcohol, or 2-furoic acid. However, the difference might be caused by the two substances 5-hydroxymethylfurfural and 2,5-furandimethanol. The present study found no difference in the amount of leached furfuryl alcohol between leachates from furfurylated softwood and furfurylated hardwood species. Earlier studies have indicated differences in grafting of furfuryl alcohol to lignin. However, nothing was found in the present study that could support this. The leachates of furfurylated wood still need to be

  16. Understanding heat transfer in 2D channel flows including recirculation

    NARCIS (Netherlands)

    Dirkse, M.H.; Loon, van W.K.P.; Stigter, J.D.; Bot, G.P.A.

    2007-01-01

    Inviscid, irrotational two-dimensional flows can be modelled using the Schwarz¿Christoffel integral. Although bounded flows including boundary layer separation and recirculation are not irrotational, a model is presented that uses the Schwarz¿Christoffel integral to model these flows. The model sepa

  17. Numerical analysis and control of the recirculation bubble strength ...

    African Journals Online (AJOL)

    user

    So et al (1985) experimentally determined jet characteristics in confined swirling ... z r u effr rr z u eff z z p z u u r u v μ μ μ μ ρ. 1. 1. (2). Radial component ..... swirl number it is possible to prevent generation of recirculation bubble in the mixing.

  18. Constrained control of a once-through boiler with recirculation

    DEFF Research Database (Denmark)

    Trangbæk, K

    2008-01-01

    There is an increasing need to operate power plants at low load for longer periods of time. When a once-through boiler operates at a sufficiently low load, recirculation is introduced, significantly altering the control structure. This paper illustrates the possibilities for using constrained con...

  19. Microorganisms in recirculating aquaculture systems and their management

    NARCIS (Netherlands)

    Rurangwa, E.; Verdegem, M.C.J.

    2015-01-01

    Recirculation aquaculture systems (RASs) are increasingly considered as production systems of the future with a minimum ecological impact for the production of aquatic food. To maintain a good water quality and to produce quality and healthy fishery products, the systems depend on a diverse microbia

  20. Use of low temperature blowers for recirculation of hot gases

    Science.gov (United States)

    Maru, H.C.; Forooque, M.

    1982-08-19

    An apparatus is described for maintaining motors at low operating temperatures during recirculation of hot gases in fuel cell operations and chemical processes such as fluidized bed coal gasification. The apparatus includes a means for separating the hot process gas from the motor using a secondary lower temperature gas, thereby minimizing the temperature increase of the motor and associated accessories.

  1. The effect of flow recirculation on abdominal aortic aneurysm

    Science.gov (United States)

    Taib, Ishkrizat; Amirnordin, Shahrin Hisham; Madon, Rais Hanizam; Mustafa, Norrizal; Osman, Kahar

    2012-06-01

    The presences of flow recirculation at the abdominal aortic aneurysm (AAA) region yield the unpredictable failure of aneurismal wall. The failure of the aneurismal wall is closely related to the hemodynamic factor. Hemodynamic factor such as pressure and velocity distribution play a significance role of aneurysm growth and rupture. By using the computational approach, the influence of hemodynamic factor is investigated using computational fluid dynamic (CFD) method on the virtual AAA model. The virtual 3D AAAs model was reconstructed from Spiral Computed Tomography scan (CT-scan). The blood flow is assumed as being transient, laminar and Newtonian within a rigid section of the vessel. The blood flow also driven by an imposed of pressure gradient in the form of physiological waveform. The pulsating blood flow is also considered in this simulation. The results on pressure distribution and velocity profile are analyzed to interpret the behaviour of flow recirculation. The results show the forming of vortices is seen at the aneurysm bulge. This vortices is form at the aneurysm region then destroyed rapidly by flow recirculation. Flow recirculation is point out much higher at distal end of aneurysm closed to iliac bifurcation. This phenomenon is managed to increase the possibility of aneurysm growth and rupture.

  2. The Comet Assay for the Evaluation of Genotoxic Potential of Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Kamila Widziewicz

    2012-01-01

    Full Text Available Genotoxic assessment of landfill leachate before and after biological treatment was conducted with two human cell lines (Me45 and NHDF and Daphnia magna somatic cells. The alkali version of comet assay was used to examine genotoxicity of leachate by DNA strand breaks analysis and its repair dynamics. The leachate samples were collected from Zabrze landfill, situated in the Upper Silesian Industrial District, Poland. Statistically significant differences (Kruskal-Wallice ANOVA rank model were observed between DNA strand breaks in cells incubated with leachate before and after treatment (P<0.001. Nonparametric Friedman ANOVA confirmed time-reliable and concentration-reliable cells response to leachate concentration. Examinations of chemical properties showed a marked decrease in leachate parameters after treatment which correlate to reduced genotoxicity towards tested cells. Obtained results demonstrate that biological cotreatment of leachate together with municipal wastewater is an efficient method for its genotoxic potential reduction; however, treated leachate still possessed genotoxic character.

  3. Chromium in soil layers and plants on closed landfill site after landfill leachate application.

    Science.gov (United States)

    Zupancic, Marija; Justin, Maja Zupancic; Bukovec, Peter; Selih, Vid Simon

    2009-06-01

    Landfill leachate (LL) usually contains low concentrations of heavy metals due to the anaerobic conditions in the methanogenic landfill body after degradation of easily degradable organic matter and the neutral pH of LL, which prevents mobilization and leaching of metals. Low average concentrations of metals were also confirmed in our extensive study on the rehabilitation of an old landfill site with vegetative landfill cover and LL recirculation after its treatment in constructed wetland. The only exception was chromium (Cr). Its concentrations in LL ranged between 0.10 and 2.75 mg/L, and were higher than the concentrations usually found in the literature. The objectives of the study were: (1) to understand why Cr is high in LL and (2) to understand the fate and transport of Cr in soil and vegetation of landfill cover due to known Cr toxicity to plants. The total concentration of Cr in LL, total and exchangeable concentrations of Cr in landfill soil cover and Cr content in the plant material were extensively monitored from May 2004 to September 2006. By obtained data on Cr concentration in different landfill constituents, supported with the data on the amount of loaded leachate, amount of precipitation and potential evapotranspiration (ETP) during the performance of the research, a detailed picture of time distribution and co-dependency of Cr is provided in this research. A highly positive correlation was found between concentrations of Cr and dissolved organic carbon (r=0.875) in LL, which indicates the co-transport of Cr and dissolved organic carbon through the system. Monitoring results showed that the substrate used in the experiment did not contribute to Cr accumulation in the landfill soil cover, resulting in percolation of a high proportion of Cr back into the waste layers and its circulation in the system. No negative effects on plant growth appeared during the monitoring period. Due to low uptake of Cr by plants (0.10-0.15 mg/kg in leaves and 0.05-0.07 mg

  4. Biosorption of gold from computer microprocessor leachate solutions using chitin.

    Science.gov (United States)

    Côrtes, Letícia N; Tanabe, Eduardo H; Bertuol, Daniel A; Dotto, Guilherme L

    2015-11-01

    The biosorption of gold from discarded computer microprocessor (DCM) leachate solutions was studied using chitin as a biosorbent. The DCM components were leached with thiourea solutions, and two procedures were tested for recovery of gold from the leachates: (1) biosorption and (2) precipitation followed by biosorption. For each procedure, the biosorption was evaluated considering kinetic, equilibrium, and thermodynamic aspects. The general order model was able to represent the kinetic behavior, and the equilibrium was well represented by the BET model. The maximum biosorption capacities were around 35 mg g(-1) for both procedures. The biosorption of gold on chitin was a spontaneous, favorable, and exothermic process. It was found that precipitation followed by biosorption resulted in the best gold recovery, because other species were removed from the leachate solution in the precipitation step. This method enabled about 80% of the gold to be recovered, using 20 g L(-1) of chitin at 298 K for 4 h.

  5. Ammonium removal from landfill leachate by anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, Adelaida [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain); Urtiaga, Ane [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain)]. E-mail: urtiaga@unican.es; Rivero, Maria-Jose [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain); Ortiz, Inmaculada [Department of Chemical Engineering, University of Cantabria, Avda. de los Castros s/n. 39005 Santander (Spain)

    2007-06-18

    The feasibility of removing ammonium from landfill leachates by electrochemical oxidation was studied. Raw leachates and biologically/physico-chemically pretreated leachates from a municipal landfill site were treated. Boron doped diamond was used as anode and stainless steel as cathode, both electrodes with an area of 70 cm{sup 2}. The effects of the applied current density (15-90 mA cm{sup -2}), the initial ammonium concentration (480-2000 mg L{sup -1}), and the initial chloride concentration were experimentally studied. Total ammonium removal was obtained after 360 min of processing and almost half of the initial ammonium nitrogen was oxidized to nitrate. On the other hand, the concentration of chloride enhanced the rate of ammonium oxidation. In addition, the amount of N-NH{sub 4} {sup +} transformed into N-NO{sub 3} {sup -} decreased when additional chloride was provided.

  6. A PRELIMINARY EXPERIMENT ON DENITRIFICATION OF WASTE LANDFILL LEACHATE

    Science.gov (United States)

    Wada, Nariaki; Nakamichi, Tamihiro; Yagi, Masahiro; Matsumoto, Toshihide; Kugimiya, Akikazu; Michioku, Kohji

    A laboratory experiment on denitrification was carried out in order to reduce nitrogen load from municipal landfill leachate. Nitrogen was efficiently removed by feeding sludge of the leachate pond into the tanks, which could activate denitrification bacteria. Although inorganic reducing agent such as iron powder was not able to make the whole water mass anoxic, denitrification took place by supplying organic matters such as methanol, hydrogen feeding agent, etc.. It is considered that small amount of anoxic water film produced on surfaces of container and carriers might contribute to denitrification, although the bulk water is kept aerobic. It is found that organic matters contained in the leachate is so insufficient that nitrification liquid circulation does not work well for denitrification.

  7. Evaluation of phytotoxicity of municipal landfill leachate before and after biological treatment

    Directory of Open Access Journals (Sweden)

    CR Klauck

    Full Text Available In the present study, leachate toxicity of a municipal solid waste landfill located in the Sinos River Valley region (southern Brazil was evaluated using plant bioassays. Leachate toxicity was assessed by analysis of seed germination and root elongation of lettuce (Lactuca sativa L. and rocket plant (Eruca sativa Mill. and root elongation of onions (Allium cepa L.. Bioassays were performed by exposing the seeds of L. sativa and E. sativa and the roots of A. cepa to raw leachate, treated leachate (biological treatment and negative control (tap water. The levels of metals detected in both samples of leachate were low, and raw leachate showed high values for ammoniacal nitrogen and total Kjeldahl nitrogen. There is a reduction in the values of several physicochemical parameters, which demonstrates the efficiency of the treatment. Both L. sativa and A. cepashowed a phytotoxic response to landfill leachate, showing reduced root elongation. However, the responses of these two plant species were different. Root elongation was significantly lower in A. cepa exposed to treated leachate, when compared to negative control, but did not show any difference when compared to raw leachate. In L. sativa, seeds exposed to the raw leachate showed significant reduction in root elongation, when compared to treated leachate and negative control. Seed germination showed no difference across the treatments. The results of the study show that plant species respond differently and that municipal solid waste landfill leachate show phytotoxicity, even after biological treatment.

  8. Evaluation of phytotoxicity of municipal landfill leachate before and after biological treatment.

    Science.gov (United States)

    Klauck, C R; Rodrigues, M A S; Silva, L B

    2015-05-01

    In the present study, leachate toxicity of a municipal solid waste landfill located in the Sinos River Valley region (southern Brazil) was evaluated using plant bioassays. Leachate toxicity was assessed by analysis of seed germination and root elongation of lettuce (Lactuca sativa L.) and rocket plant Eruca sativa Mill.) and root elongation of onions Allium cepa L.). Bioassays were performed by exposing the seeds of L. sativa and E. sativa and the roots of A. cepa to raw leachate, treated leachate (biological treatment) and negative control (tap water). The levels of metals detected in both samples of leachate were low, and raw leachate showed high values for ammoniacal nitrogen and total Kjeldahl nitrogen. There is a reduction in the values of several physicochemical parameters, which demonstrates the efficiency of the treatment. Both L. sativa and A. cepa showed a phytotoxic response to landfill leachate, showing reduced root elongation. However, the responses of these two plant species were different. Root elongation was significantly lower in A. cepa exposed to treated leachate, when compared to negative control, but did not show any difference when compared to raw leachate. In L. sativa, seeds exposed to the raw leachate showed significant reduction in root elongation, when compared to treated leachate and negative control. Seed germination showed no difference across the treatments. The results of the study show that plant species respond differently and that municipal solid waste landfill leachate show phytotoxicity, even after biological treatment.

  9. Development of methods for detecting viruses in solid waste landfill leachates.

    Science.gov (United States)

    Sobsey, M D; Wallis, C; Melnick, J L

    1974-08-01

    Methods were developed for detecting and concentrating enteric viruses in municipal solid waste landfill leachates. Poliovirus added to a leachate was not readily detectable, possibly because the virus was adsorbed to the leachate particulates. The masking effects associated with suspended solids in the leachate were overcome by adding a final 0.1 M sodium (tetra)ethylenediaminetetraacetate concentration to the leachate. A sodium (tetra)ethylenediaminetetraacetate-treated leachate could be clarified by filtration at pH 8.0 without a loss of virus. The clarified and sodium (tetra)ethylenediaminetetraacetate-treated leachate contained interfering materials of an anionic nature which prevented virus adsorption to epoxy-fiber glass filters. This interfering effect was overcome by treating the leachate with an anion-exchange resin. Viruses in the resin-treated leachate were concentrated by adjusting the leachate to pH 3.5, adding AlCl(3) to a final 0.005 M concentration, adsorbing the viruses to an epoxy-fiber glass virus adsorbent, and eluting the adsorbed viruses in a small volume. When this method was used to concentrate poliovirus 100-fold in a variety of leachates, the average virus recovery efficiency was 37%. With the methods described in this study, it should be possible to efficiently monitor solid waste disposal site leachates for enteric viruses.

  10. Choosing tree genotypes for phytoremediation of landfill leachate using phyto-recurrent selection

    Science.gov (United States)

    Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Richard B. Hall

    2007-01-01

    Information about the response of poplar (Populus spp.) genotypes to landfill leachate irrigation is needed, along with efficient methods for choosing genotypes based on leachate composition. Poplar clones were irrigated during three cycles of phyto-recurrent selection to test whether genotypes responded differently to leachate and water, and to test...

  11. Application of photochemical technologies for treatment of landfill leachate

    Energy Technology Data Exchange (ETDEWEB)

    Meeroff, Daniel E., E-mail: dmeeroff@fau.edu [Department of Civil, Environmental and Geomatics Engineering, Florida Atlantic University, Boca Raton, FL (United States); Bloetscher, Frederick; Reddy, D.V.; Gasnier, Francois; Jain, Swapnil; McBarnette, Andre; Hamaguchi, Hatsuko [Department of Civil, Environmental and Geomatics Engineering, Florida Atlantic University, Boca Raton, FL (United States)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Photochemical iron-mediated aeration and TiO{sub 2} photocatalysis for leachate treatment. Black-Right-Pointing-Pointer Removal efficiency tested on COD, BOD{sub 5}, color, ammonia, and lead. Black-Right-Pointing-Pointer Contact times for 90% removal were 10-200 h for PIMA Black-Right-Pointing-Pointer Contact times for 90% removal were 3-37 h for TiO{sub 2} photocatalysis. Black-Right-Pointing-Pointer Pre-filtration is not necessary. - Abstract: Because of widely varying practices in solid waste management, an all-inclusive solution to long-term management of landfill leachate is currently not available. There is a major technological need for sustainable, economical options for safe discharge of leachate to the environment. Two potential on-site pretreatment technologies, photochemical iron-mediated aeration (PIMA) and TiO{sub 2} photocatalysis were compared for treatment of landfill leachate at laboratory scale. Results of bench scale testing of real landfill leachate with PIMA and TiO{sub 2} photocatalysis showed up to 86% conversion of refractory COD to complete mineralization, up to 91% removal of lead, up to 71% removal of ammonia without pH adjustment, and up to 90% effective color removal with detention times between 4 and 6 h, in field samples. The estimated contact times for 90% removal of COD, ammonia, lead, and color were found to be on the order of 10-200 h for PIMA and 3-37 h for TiO{sub 2} photocatalysis. Testing with actual leachate samples showed 85% TiO{sub 2} photocatalyst recovery efficiency with no loss in performance after multiple (n > 4 uses). Pre-filtration was not found to be necessary for effective treatment using either process.

  12. Redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Downgradient from an old municipal landfill allowing leachate, rich in dissolved organic carbon, to enter a shallow sandy aerobic aquifer, a sequence of redoxe zones is identified from groundwater chemical analysis. Below the landfill, methanogenic conditions prevail, followed by sulfidogenic......, ferrogenic, nitrate-reducing and aerobic environments overa distance of 370 m. This redox zone sequence is consistent with thermodynamical principles and is closely matched by the leachate plume determined by the chloride plume distribution. The redox zone sequence is believed to be key in controlling...

  13. LCA and economic evaluation of landfill leachate and gas technologies

    DEFF Research Database (Denmark)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna Kristina

    2011-01-01

    improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to −0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE).For the toxic...... through emissions of treated wastewater to surface waters.The largest environmental improvement with regard to the direct cost of the landfill was the capping and leachate treatment system. The capping, though very cheap to establish, gave a huge benefit in lowered impacts, the leachate collection system...

  14. Landfill leachate effects on sorption of organic micropollutants onto aquifer materials

    DEFF Research Database (Denmark)

    Larsen, Thomas; Christensen, Thomas Højlund; Pfeffer, Fred M.;

    1992-01-01

    content. The experiments showed that hydrophobic organic micropollutants do partition into dissolved organic carbon found in landfill leachate potentially increasing their mobility. However, landfill leachate interacted with aquifer materials apparently increases the sorbent affinity for the hydrophobic......The effect of dissolved organic carbon as present in landfill leachate, on the sorption of organic micropollutants in aquifer materials was studied by laboratory batch and column experiments involving 15 non-polar organic chemicals, 5 landfill leachates and 4 aquifer materials of low organic carbon......, the effect of landfill leachate on retardation of organic micropollutants in aquifer material seems limited....

  15. Use of Combined Coagulation-Adsorption Process as Pretreatment of Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Sreekrishnaperumal Thanga Ramesh

    2013-03-01

    Full Text Available Landfill leachate is an important pollution factor resulting from municipal landfill sites. Physical and chemical processes are the better option for pretreatment or full treatment of landfill leachate. This article presents a combination of pre-treatment method (coagulation and adsorption for leachate collected from municipal solid waste open dumping site. Physico chemical characteristics of stabilized and fresh leachate were examined. Coagulation process was examined by using alum and ferric chloride. A low cost adsorbent, fly ash was used for adsorption studies. Coagulation studies were carried out for fresh and stabilized leachate. Adsorption studies have been conducted for alum pre-treated stabilized leachate. Effect of coagulant dose, adsorbent dose, pH and contact time were carried out. The effective optimum coagulant dosages were 0.6 g/L and 0.7 g/L for alum and ferric chloride respectively for stabilized leachate and incase of fresh leachate 0.8 g/L and 0.6 g/L for alum and ferric chloride respectively. For the alum pretreated stabilized leachate, the maximum COD removal is 28% using fly ash adsorbent with equilibrium time of 210 min and optimum dose of 6 g/L. Overall COD removal efficiency of 82% was obtained by coagulation using alum and adsorption using fly ash for stabilized leachate. The results obtained showed that combined coagulation and adsorption process can be used effectively for stabilized leachate treatment.

  16. Use of combined coagulation-adsorption process as pretreatment of landfill leachate.

    Science.gov (United States)

    Gandhimathi, Rajan; Durai, Nalladurai Jegan; Nidheesh, Puthiya Veetil; Ramesh, Sreekrishnaperumal Thanga; Kanmani, Subramaniam

    2013-03-21

    Landfill leachate is an important pollution factor resulting from municipal landfill sites. Physical and chemical processes are the better option for pretreatment or full treatment of landfill leachate. This article presents a combination of pre-treatment method (coagulation and adsorption) for leachate collected from municipal solid waste open dumping site. Physico chemical characteristics of stabilized and fresh leachate were examined. Coagulation process was examined by using alum and ferric chloride. A low cost adsorbent, fly ash was used for adsorption studies. Coagulation studies were carried out for fresh and stabilized leachate. Adsorption studies have been conducted for alum pre-treated stabilized leachate. Effect of coagulant dose, adsorbent dose, pH and contact time were carried out. The effective optimum coagulant dosages were 0.6 g/L and 0.7 g/L for alum and ferric chloride respectively for stabilized leachate and incase of fresh leachate 0.8 g/L and 0.6 g/L for alum and ferric chloride respectively. For the alum pretreated stabilized leachate, the maximum COD removal is 28% using fly ash adsorbent with equilibrium time of 210 min and optimum dose of 6 g/L. Overall COD removal efficiency of 82% was obtained by coagulation using alum and adsorption using fly ash for stabilized leachate. The results obtained showed that combined coagulation and adsorption process can be used effectively for stabilized leachate treatment.

  17. Redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Downgradient from an old municipal landfill allowing leachate, rich in dissolved organic carbon, to enter a shallow sandy aerobic aquifer, a sequence of redoxe zones is identified from groundwater chemical analysis. Below the landfill, methanogenic conditions prevail, followed by sulfidogenic...... the fate of reactive pollutants leached from the landfill....

  18. A feruloyl esterase derived from a leachate metagenome library

    CSIR Research Space (South Africa)

    Rashamuse, K

    2012-01-01

    Full Text Available A feruloyl esterase encoding gene (designated fae6), derived from a leachate metagenomic library, was cloned and the nucleotide sequence of the insert DNA determined. Translational analysis revealed that fae6 consists of a 515 amino acid polypeptide...

  19. Ammonia removal from leachate solution using natural Chinese clinoptilolite.

    Science.gov (United States)

    Wang, Yuqiu; Liu, Shijun; Xu, Ze; Han, Tianwei; Chuan, Sun; Zhu, Tan

    2006-08-25

    This paper assesses the potential of natural Chinese clinoptilolite for ammonia removal from the leachate solution of sewage sludge. In batch study the effects of relevant parameters, such as contact time, initial ammonia concentration and particle size of clinoptilolite, were examined respectively. The results show that the data obtained from batch studies were fit to Langmuir and Freundlich isotherms and the Langmuir isotherms reflect more reasonable for ammonium ion uptake onto clinoptilolite; the clinoptilolite adsorption process has been proved effective, at laboratory scale, the maximum adsorption capacity of the clinoptilolite, for ammonium concentration ranging from 11.12 to 115.16 mg NH(4)-N L(-1) in leachate solution, was about 1.74 mg NH(4)-Ng(-1); the time to adsorption equilibrium was 2.5 h in leachate solution and 1.5 h more than for in NH(4)Cl synthetic solution; ammonium adsorption increased with decreasing clinoptilolite particle size; the ammonia removal capacity of clinoptilolite increased with increasing initial ammonia concentration. It is believed that as adsorption agent for NH(4)-N removal from sludge leachate, natural Chinese clinoptilolite can be feasible.

  20. Treatment of landfill leachate using Solar UV facilitated ...

    African Journals Online (AJOL)

    Journal Home > Vol 11, No 2 (2016) > ... The use of heterogeneous photocatalytic degradation for the treatment of landfill leachate was investigated in this study. The photocatalytic degradation studies were carried out using Zinc oxide (ZnO) as ... Cameroon (8); Congo, Republic (1); Côte d'Ivoire (4); Egypt, Arab Rep.

  1. Plant Leachate Nutrient Recovery with Biological, Thermal, and Photocatalytic Pretreatments

    Science.gov (United States)

    Wong, Les

    2015-01-01

    Plants are ideal for long term space travel: provide essential resources - oxygen, water, food; Water-soaked plants expel soluble nutrients in a leachate solution - toxins and wastes are also expelled and inhibit growth; biological, thermal, photocatalytic coupled with an acid digestion treatment will hopefully maximize recovery and remove wastes

  2. Composition of leachate from old landfills in Denmark

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Christophersen, Mette

    2001-01-01

    smaller landfills by a comprehensive review of the investigations carried out by the counties. In total 106 landfills were selected by criteria avoiding dilution effects. A database was constructed using a standard program. Statistical evaluations showed that the leachate concentrations in general...

  3. Treatment of landfill leachate: Removal of ammonia by struvite ...

    African Journals Online (AJOL)

    2014-06-30

    Jun 30, 2014 ... from the leachate exceeded 85% when the reaction was performed at an initial pH of 10.0. The highest ... into biological reactors for activated sludge. Chemical precipitation in the form of the double salt of magnesium and ...

  4. Treating leachate mixture with anaerobic ammonium oxidation technology

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-guo; ZHOU Shao-qi

    2006-01-01

    Large amounts of ammonium and a low content of biodegradable chemical oxygen demand(COD) are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment.Treatment effect of anaerobic ammonium oxidation (anammox) process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%,74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. The demand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the influent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.

  5. Ammonia removal from landfill leachate by air stripping and absorption.

    Science.gov (United States)

    Ferraz, Fernanda M; Povinelli, Jurandyr; Vieira, Eny Maria

    2013-01-01

    An old landfill leachate was pre-treated in a pilot-scale aerated packed tower operated in batch mode for total ammoniacal nitrogen (TAN) removal. The stripped ammonia was recovered with a 0.4 mol L(-1) H2SO4 solution, deionized water and tap water. Ca(OH)2 (95% purity) or commercial hydrated lime was added to the raw leachate to adjust its pH to 11, causing removal of colour (82%) and heavy metals (70-90% for Zn, Fe and Mn). The 0.4 molL(-1) H2SO4 solution was able to neutralize 80% of the stripped ammonia removed from 12 L of leachate. The effectiveness of the neutralization of ammonia with deionized water was 75%. Treating 100 L of leachate, the air stripping tower removed 88% of TAN after 72 h of aeration, and 87% of the stripped ammonia was recovered in two 31 L pilot-scale absorption units filled with 20 L of tap water.

  6. Tracking studies in eRHIC energy-recovery recirculator

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-07-13

    Beam and polarization tracking studies in eRHIC energy recovery electron recirculator are presented, based on a very preliminary design of the FFAG lattice. These simulations provide examples of some of the beam and spin optics aspects of the linear FFAG lattice concept and its application in eRHIC, they provide code benchmarking for synchrotron radiation and spin diffusion in addition, and pave the way towards end-to-end 6-D(phasespace)+3D(spin) tracking simulations.

  7. Control of synchrotron radiation effects during recirculation with bunch compression

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Benson, Stephen [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Krafft, Geoffrey [Old Dominion Univ., Norfolk, VA (United States); Terzic, Balsa [Old Dominion Univ., Norfolk, VA (United States); Tsai, Cheng [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2015-05-01

    Studies of beam quality during recirculation have been extended to an arc providing bunch compression with positive momentum compaction. It controls both incoherent and coherent synchrotron radiation (ISR and CSR) using methods including optics balance and generates little microbunching gain. We detail the dynamical basis for the design, discuss the design process, give an example, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of microbunching effects.

  8. Filter System Performance in a Tilapia Recirculating System

    Directory of Open Access Journals (Sweden)

    Cristian Savin

    2012-10-01

    Full Text Available It is known that recirculating aquaculture systems, although has some advantages, production costs resulting from these production systems are quite high and is mainly due to the filtration system of technological water. Tilapia is one of the most important species in world aquaculture, the second production after carp, because of the advantages it has being reared in any production system: ponds, net-pens, cages, raceways, recirculating systems. Aim of this study was to evaluate the performance of a filter system in a tilapia recirculating system. Experiments were conducted during October – December 2011, during which feeding was done only with feed, Nutra category, ageappropriate granulation. Main physical – chemical parameters of technological water were monitored, pH, dissolved oxygen, nitrite, ammonia and ammonium, both the water entry in the filter and the exit from the filter. Filtration efficiency varied from 2-3% and up to 50-60%, mainly due to rapid loading of the filter and its need for cleaning.

  9. Mathematical model for analysis of recirculating vertical flow constructed wetlands.

    Science.gov (United States)

    Sklarz, Menachem Y; Gross, Amit; Soares, M Ines M; Yakirevich, Alexander

    2010-03-01

    The recirculating vertical flow constructed wetland (RVFCW) was developed for the treatment of domestic wastewater (DWW). In this system, DWW is applied to a vertical flow bed through which it trickles into a reservoir located beneath the bed. It is then recirculated back to the root zone of the bed. In this study, a compartmental model was developed to simulate the RVFCW. The model, which addresses transport and removal kinetics of total suspended solids, 5-day biological oxygen demand and nitrogen, was fitted to kinetical results obtained from pilot field setups and a local sensitivity analysis was performed on the model parameters and operational conditions. This analysis showed that after 5h of treatment water quality is affected more by stochastic events than by the model parameter values, emphasizing the stability of the RVFCW system to large variations in operational conditions. Effluent quality after 1h of treatment, when the sensitivity analysis showed the parameter impacts to be largest, was compared to model predictions. The removal rate was found to be dependent on the recirculation rate. The predictions correlated well with experimental observations, leading to the conclusion that the proposed model is a satisfactory tool for studying RVFCWs. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Hydroxyl time series and recirculation in turbulent nonpremixed swirling flames

    Energy Technology Data Exchange (ETDEWEB)

    Guttenfelder, Walter A.; Laurendeau, Normand M.; Ji, Jun; King, Galen B.; Gore, Jay P. [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907-1288 (United States); Renfro, Michael W. [Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269-3139 (United States)

    2006-10-15

    Time-series measurements of OH, as related to accompanying flow structures, are reported using picosecond time-resolved laser-induced fluorescence (PITLIF) and particle-imaging velocimetry (PIV) for turbulent, swirling, nonpremixed methane-air flames. The [OH] data portray a primary reaction zone surrounding the internal recirculation zone, with residual OH in the recirculation zone approaching chemical equilibrium. Modeling of the OH electronic quenching environment, when compared to fluorescence lifetime measurements, offers additional evidence that the reaction zone burns as a partially premixed flame. A time-series analysis affirms the presence of thin flamelet-like regions based on the relation between swirl-induced turbulence and fluctuations of [OH] in the reaction and recirculation zones. The OH integral time-scales are found to correspond qualitatively to local mean velocities. Furthermore, quantitative dependencies can be established with respect to axial position, Reynolds number, and global equivalence ratio. Given these relationships, the OH time-scales, and thus the primary reaction zone, appear to be dominated by convection-driven fluctuations. Surprisingly, the OH time-scales for these nominally swirling flames demonstrate significant similarities to previous PITLIF results in nonpremixed jet flames. (author)

  11. Attenuation of municipal landfill leachate through land treatment.

    Science.gov (United States)

    Pazoki, Maryam; Abdoli, Mohammad Ali; Karbassi, Abdolreza; Mehrdadi, Naser; Yaghmaeian, Kamyar

    2014-01-07

    The treatment of municipal landfill's leachate is considered as one of the most significant environmental issues. In this study a laboratory experiment was conducted through land treatment, achieving an efficient and economical method by using Vetiver plant. Moreover, the effects of land treatment of leachate of municipal landfills on the natural reduction of organic and inorganic contaminants in the leachate after the pre-treatment in the Aradkouh disposal center are invested. Three pilots including the under-investigation region's soil planted by Vetiver plant, the region's intact soil pilot and the artificial composition of the region's soil including the natural region's soil, sand, and rock stone are used. The leachate, having passed its initial treatment, passed through the soil and to the pilot. It was collected in the end of the pilots and its organic and inorganic contaminants were measured. However, the land treatment of leachate was conducted in a slow rate at various speeds. According to the results, in order to remove COD, BOD5, TDS, TSS, TOC the best result was obtained in the region's soil planted with Vetiver plant and at the speed of 0.2 ml per minute which resulted 99.1%, 99.7%, 52.4%, 98.8%, 94.9% removal efficiencies, respectively. It also can be concluded that the higher the organic rate load is, the lower the efficiency of the removal would be. In addition, EC & pH were measured and the best result was obtained in the region's soil planted with Vetiver plant and at the speed of 0.2 ml/min.

  12. Investigation of Microbunching Instabilities in Modern Recirculating Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2017-05-21

    Particle accelerators are machines to accelerate and store charged particles, such as electrons or protons, to the energy levels for various scientific applications. A collection of charged particles usually forms a particle beam. There are three basic types of particle accelerators: linear accelerators (linac), storage-ring (or circular) accelerators, and recirculating accelerators. In a linac, particles are accelerated and pass through once along a linear or straight beamline. Storage-ring accelerators propel particles around a circular track and repetitively append the energy to the stored beam. The third type, also the most recent one in chronology, the recirculating accelerator, is designed to accelerate the particle beam in a short section of linac, circulate the beam, and then either continue to accelerate for energy boost or decelerate it for energy recovery. The beam properties of a linac machine are set at best by the initial particle sources. For storage rings, the beam equilibria are instead determined by the overall machine design. The modern recirculating machines share with linacs the advantages to both accelerate and preserve the beam with high beam quality, as well as efficiently reuse the accelerating components. The beamline design in such a machine configuration can however be much more complicated than that of linacs. As modern accelerators push toward the high-brightness or high-intensity frontier by demanding particles in a highly charged bunch (about nano-Coulomb per bunch) to concentrate in an ever-decreasing beam phase space (transverse normalized emittance about 1 μm and relative energy spread of the order of 10^-5 in GeV beam energy), the interaction amongst particles via their self-generated electromagnetic fields can potentially lead to coherent instabilities of the beam and thus pose significant challenges to the machine design and operation. In the past decade and a half, microbunching instability (MBI) has been one of the most

  13. Nitrogen oxides emissions from the MILD combustion with the conditions of recirculation gas.

    Science.gov (United States)

    Park, Min; Shim, Sung Hoon; Jeong, Sang Hyun; Oh, Kwang-Joong; Lee, Sang-Sup

    2017-04-01

    The nitrogen oxides (NOx) reduction technology by combustion modification which has economic benefits as a method of controlling NOx emitted in the combustion process, has recently been receiving a lot of attention. Especially, the moderate or intense low oxygen dilution (MILD) combustion which applied high temperature flue gas recirculation has been confirmed for its effectiveness with regard to solid fuel as well. MILD combustion is affected by the flue gas recirculation ratio and the composition of recirculation gas, so its NOx reduction efficiency is determined by them. In order to investigate the influence of factors which determine the reduction efficiency of NOx in MILD coal combustion, this study changed the flow rate and concentration of nitrogen (N2), carbon dioxide (CO2) and steam (H2O) which simulate the recirculation gas during the MILD coal combustion using our lab-scale drop tube furnace and performed the combustion experiment. As a result, its influence by the composition of recirculation gas was insignificant and it was shown that flue gas recirculation ratio influences the change of NOx concentration greatly. We investigated the influence of factors determining the nitrogen oxides (NOx) reduction efficiency in MILD coal combustion, which applied high-temperature flue gas recirculation. Using a lab-scale drop tube furnace and simulated recirculation gas, we conducted combustion testing changing the recirculation gas conditions. We found that the flue gas recirculation ratio influences the reduction of NOx emissions the most.

  14. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    Science.gov (United States)

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-01-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50–75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants’ exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation. PMID:28781568

  15. Simultaneously reducing CO2 and particulate exposures via fractional recirculation of vehicle cabin air

    Science.gov (United States)

    Jung, Heejung S.; Grady, Michael L.; Victoroff, Tristan; Miller, Arthur L.

    2017-07-01

    Prior studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. This study proposes a fractional air recirculation system for reducing nanoparticle concentration while simultaneously suppressing CO2 levels in the cabin. Several recirculation scenarios were tested using a custom-programmed HVAC (heat, ventilation, air conditioning) unit that varied the recirculation door angle in the test vehicle. Operating the recirculation system with a standard cabin filter reduced particle concentrations to 1000 particles/cm3, although CO2 levels rose to 3000 ppm. When as little as 25% fresh air was introduced (75% recirculation), CO2 levels dropped to 1000 ppm, while particle concentrations remained below 5000 particles/cm3. We found that nanoparticles were removed selectively during recirculation and demonstrated the trade-off between cabin CO2 concentration and cabin particle concentration using fractional air recirculation. Data showed significant increases in CO2 levels during 100% recirculation. For various fan speeds, recirculation fractions of 50-75% maintained lower CO2 levels in the cabin, while still reducing particulate levels. We recommend fractional recirculation as a simple method to reduce occupants' exposures to particulate matter and CO2 in vehicles. A design with several fractional recirculation settings could allow air exchange adequate for reducing both particulate and CO2 exposures. Developing this technology could lead to reductions in airborne nanoparticle exposure, while also mitigating safety risks from CO2 accumulation.

  16. Experimental plant for the physical-chemical treatment of groundwater polluted by Municipal Solid Waste (MSW leachate, with ammonia recovery

    Directory of Open Access Journals (Sweden)

    Massimo Raboni

    2013-12-01

    Full Text Available The paper documents the results of the experimental treatment of groundwater (flow rate: 300 m3 h-1 polluted by the leachate of an old MSW landfill (7 million tonnes in northern Italy. The process consists of a coagulation-flocculation pre-treatment at pH > 11, and subsequent ammonia stripping, after heating the water to 35-38 °C by means of the biogas produced by the landfill. The stripped ammonia was recovered by absorption with sulfuric acid, producing a 30% solution of ammonium sulfate, which was reused as a base fertilizer. In addition, the paper reports important operational aspects related to the scaling of the stripping tower’s packing and its effect on pH and temperature profiles inside the towers caused by the closed loop, which recirculates the stripping air coming from the ammonia absorption towers with sulfuric acid. The average removal efficiency of ammonia reached 95.4% with an inlet mean concentration of 199.0 mg L-1.

  17. Phytotoxic Effect of Landfill and Leachate Pollution Indexes on Germination and Seedling of Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Márquez-Benavides Liliana

    2014-08-01

    Full Text Available Appropriate solid waste management includes leachate management, an effluent that results from the degradation of solid waste, moisture content and pluvial additions to the disposal site. Due to poor management of the landfill, sometimes leachate is likely to reach nearby areas, affecting soil water and vegetal area. A powerful tool to assess the pollution potential of a given leachate is the leachate pollution index (LPI developed by Kummar & Alappat (2005 that evaluates 18 parameters in order to calculate a value between 5-100 being 100 the highest in pollution potential. The LPI allows the comparison between leachates from different sites and ages, and also assists in the decision making process on leachate treatment. However, it is currently unknown if this value can also be related to the fitotóxico effect of a leachate on Phaseolus vulgaris L. The aim of this work was to calculate the LPI of two leachates and compare the effect on P. vulgaris L (common bean. A greenhouse scale experiment was set up, the studied variables were seed germination per cent (% and phenotype of P. vulgaris at seedling step after treated with several leachate concentrations from Guanajuato (GTO and Toluca (TOL, México. Results showed that a greater LPI (34.8 from GTO did not correspond to a largest fitotoxic effect on P. vulgaris. This bioassay could be a completely tool with LPI to evaluate pollution potential of leachate approaching to normal environmental conditions.

  18. Evaluation of a rainbow trout (Oncorhynchus mikyss) culture water recirculating system

    OpenAIRE

    Iván Sánchez O; Wilmer Sanguino O.; Ariel Gómez C.; Roberto García C

    2014-01-01

    ABSTRACTObjective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss) fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tu...

  19. Ecotoxicological assessment and evaluation of a pine bark biosorbent treatment of five landfill leachates.

    Science.gov (United States)

    Ribé, Veronica; Nehrenheim, Emma; Odlare, Monica; Gustavsson, Lillemor; Berglind, Rune; Forsberg, Ake

    2012-10-01

    When selecting a landfill leachate treatment method the contaminant composition of the leachate should be considered in order to obtain the most cost-effective treatment option. In this study the filter material pine bark was evaluated as a treatment for five landfill leachates originating from different cells of the same landfill in Sweden. The objective of the study was to determine the uptake, or release, of metals and dissolved organic carbon (DOC) during a leaching test using the pine bark filter material with the five different landfill leachates. Furthermore the change of toxicity after treatment was studied using a battery of aquatic bioassays assessing luminescent bacteria (Vibrio fischeri) acute toxicity (30-min Microtox®), immobility of the crustacean Daphnia magna, growth inhibition of the algae Pseudokirchneriella subcapitata and the aquatic plant Lemna minor; and genotoxicity with the bacterial Umu-C assay. The results from the toxicity tests and the chemical analysis were analyzed in a Principal Component Analysis and the toxicity of the samples before and after treatment was evaluated in a toxicity classification. The pine bark filter material reduced the concentrations of metal contaminants from the landfill leachates in the study, with some exceptions for Cu and Cd. The Zn uptake of the filter was high for heavily contaminated leachates (≥73%), although some desorption of zinc occurred in less contaminated waters. Some of the leachates may require further treatment due to discharge into a natural recipient in order to reduce the risk of possible biological effects. The difference in pH changes between the different leachates was probably due to variations in buffering capacity, affected by physicochemical properties of the leachate. The greatest desorption of phenol during filtration occurred in leachates with high conductivity or elevated levels of metals or salts. Generally, the toxicity classification of the leachates implies that although

  20. Applying rotary jet heads for mixing and mass transfer in a forced recirculation tank reactor system

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Grotkjær, Thomas; Hummer, J.S.

    2003-01-01

    An approximation to an ideally mixed tank reactor can be obtained by vigorous stirring with mechanical mixers. For an aerated reactor the gas dispersion contributes to the mixing process. Mixing can also be achieved by recirculation of a portion of the liquid through either an internal...... at 1-9 bar gauge pressure into the bulk liquid. Liquid feed can be added to the bulk volume or it may be injected into the pressurized recirculation loop. Gas is always fed to the recirculation loop, and the heat of reaction is removed in a plate-type heat exchanger inserted in the recirculation loop...

  1. Microbial reduction of hexavalent chromium by landfill leachate.

    Science.gov (United States)

    Li, Yarong; Low, Gary K-C; Scott, Jason A; Amal, Rose

    2007-04-02

    The reduction of hexavalent chromium (Cr(VI)) in municipal landfill leachates (MLL) and a non-putrescible landfill leachate (NPLL) was investigated. Complete Cr(VI) reduction was achieved within 17 days in a MLL when spiked with 100 mg l(-1) Cr(VI) or less. In the same period, negligible Cr(VI) reduction was observed in NPLL. In MLL, Cr(VI) reduction was demonstrated to be a function of initial Cr(VI) concentration and bacterial biomass and organic matter concentrations. The bacteria were observed to tolerate 250 mg l(-1) Cr(VI) in MLL and had an optimal growth activity at pH 7.4 in a growth medium. The MLL also possessed an ability to sequentially reduce Cr(VI) over three consecutive spiking cycles.

  2. Contamination of Ground Water Due To Landfill Leachate

    Directory of Open Access Journals (Sweden)

    M. V. S. Raju

    2012-12-01

    Full Text Available The present site under investigation at Ajitsingh Nagar in Vijayawada of Andhra Pradesh is initially a low lying area and used for disposing the urban solid waste for the last few years, through open dumping with out taking any measures to protect the Ground water against pollution. The present study has been taken up to measure the degree of pollution of ground water due to leachate produced in the landfill site. Bore holes were made at eight random locations to measure the depth and characteristics of solid waste. Four sampling wells were made for the collection of ground water samples and they were analyzed for various parameters. All parameters were measured based on Standard methods. It is found that the ground water is contaminated due leachates of Landfill to the large extent and is not suitable for Drinking, Domestic and Irrigation purposes.

  3. Artificial sweeteners as potential tracers of municipal landfill leachate.

    Science.gov (United States)

    Roy, James W; Van Stempvoort, Dale R; Bickerton, Greg

    2014-01-01

    Artificial sweeteners are gaining acceptance as tracers of human wastewater in the environment. The 3 artificial sweeteners analyzed in this study were detected in leachate or leachate-impacted groundwater at levels comparable to those of untreated wastewater at 14 of 15 municipal landfill sites tested, including several closed for >50 years. Saccharin was the dominant sweetener in old (pre-1990) landfills, while newer landfills were dominated by saccharin and acesulfame (introduced 2 decades ago; dominant in wastewater). Cyclamate was also detected, but less frequently. A case study at one site illustrates the use of artificial sweeteners to identify a landfill-impacted groundwater plume discharging to a stream. The study results suggest that artificial sweeteners can be useful tracers for current and legacy landfill contamination, with relative abundances of the sweeteners potentially providing diagnostic ability to distinguish different landfills or landfill cells, including crude age-dating, and to distinguish landfill and wastewater sources.

  4. A power recirculating test rig for ball screw endurance tests

    Directory of Open Access Journals (Sweden)

    Giberti Hermes

    2016-01-01

    Full Text Available A conceptual design of an innovative test rig for endurance tests of ball screws is presented in this paper. The test rig layout is based on the power recirculating principle and it also allows to overtake the main critical issues of the ball screw endurance tests. Among these there are the high power required to make the test, the lengthy duration of the same and the high loads between the screw and the frame that holds it. The article describes the test rig designed scheme, the kinematic expedients to be adopted in order to obtain the required performance and functionality and the sizing procedure to choose the actuation system.

  5. A recirculating hydroponic system for studying peanut (Arachis hypogaea L.)

    Science.gov (United States)

    Mackowiak, C. L.; Wheeler, R. M.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Sager, J. C. (Principal Investigator)

    1998-01-01

    Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.

  6. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept....... Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k0a) being equivalent for all twelve...

  7. Tools to Predict Beam Breakup in Recirculating Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Beard; Nikolitsa Merminga; Byung Yunn

    2003-05-01

    An important limitation on the maximum beam current in a recirculating linac is due to beam breakup caused by higher order modes (HOM) excited in the RF cavities. A HOM delivers a transverse kick to a beam bunch, the bunch on the next pass can then drive the HOM and cause it to grow until the beam is lost. Two codes, MATBBU1 and TDBBU2, have been written to estimate the threshold current for a set of HOMs and accelerator optics. The relative merits and limitations of each is discussed in detail.

  8. Laser scanning of a recirculation zone on the Bolund escarpment

    DEFF Research Database (Denmark)

    Mann, Jakob; Angelou, Nikolas; Sjöholm, Mikael;

    2012-01-01

    Rapid variations in the height of the recirculation zone are measured with a scanning wind lidar over a small escarpment on the Bolund Peninsula. The lidar is essentially a continuous-wave laser Doppler anemometer with the capability of rapidly changing the focus distance and the beam direction....... The instrument measures the line-ofsight velocity 390 times per second and scans ten wind profiles from the ground up to seven meters per second. The results will be used to test computational fluid dynamics models for flow over terrain, and has relevance for wind energy. The development of multiple lidar...

  9. Review of the literature on leachates from coal storage piles

    Energy Technology Data Exchange (ETDEWEB)

    Davis, E.C.; Boegly, W.J. Jr.

    1978-01-01

    Runoff from coal storage piles associated with coal conversion or combustion facilities may represent a potential source of environmental pollution. This report is an assessment of existing information on coal pile leachate. The assessment indicates that few detailed studies have been conducted to date, and these are limited and the results are highly variable. More detailed long-range studies using various types of coal are recommended. These studies should be carried out both in the laboratory and in field-scale experiments.

  10. Analysis of parameters for leachate treatment in a greenhouse system

    Directory of Open Access Journals (Sweden)

    Ana Laura Gómez Blasco

    2017-06-01

    Full Text Available In this paper is presented an approach for landfill leachate treatment using enhanced natural evaporation. Experimental set up considered using a greenhouse pilot prototype placed into the municipal landfill of Puebla city, México. The greenhouse was built with a basement surface enough to place 9 trays with leachate. Treatment follow up was done through the following parameters: air temperature inside and outside the greenhouse; leachate temperature at surface and middle liquid height. Results of the first set of experiments defined a minimal initial liquid height of 20% in respect to the tray height; the 2nd set allowed defining optimal evaporation rate conditions evaluated in respect of a tray placed outside, considered as reference of 100% efficiency (blank, obtained results showed that morning and night processes provided efficiencies up to 2 times the reference; otherwise, afternoon measurements showed similar temperature values inside and outside. In general collected data at winter season provided efficiencies between 82% and 147%, in periods of 24 h, it was observed that higher liquid reductions took place at North, and lower ones at the South positions. Based on these results it was proposed a 20 days experiment, using stagnant (E and recharge (R conditions referred to the blank (L, the R process showed greater efficiency (168% than the stagnant one (158%. Leachate chemical characterization indicates that pH is highly stable; while total solids, chemical oxygen demand, sulfate and chloride exhibit an increase in concentration reaching values of 1.2–2.5 times the initial concentration, phosphate was the only parameter exhibiting a decreasing trend ending with 40% of its initial concentration.

  11. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  12. Plants Role in Reducing Heavy Metals from Polluted Soil Leachate

    Directory of Open Access Journals (Sweden)

    Amouei A.* PhD,

    2015-09-01

    Full Text Available Aims In the past few decades, more attention has been paid to clean up soils polluted with heavy metals by plants. A serious problem in this way is the amount of heavy metals uptake by plants. This study was conducted to evaluate the effectiveness of 3 local plants of Mazandaran province, Iran, in reducing and controlling the soil’s heavy metals. Instrument & Methods The removal amount of three heavy metals (lead, zinc and cadmium by native plants (maize, velvetleaf and wild amaranth was investigated in alkaline (pH=8 and acidic (pH=5 soils and also using three substances such as EDTA, ammonium citrate and phosphate. The concentrations of these metals in leachate were measured by using atomic absorption spectrometry method. Findings Lead, cadmium and zinc levels in leachate in treatments with plants were less than unplanted ones. The concentrations of these metals in the produced leachate of treatments with acidic soils were higher than those with alkaline soils. In the treatments of soil polluted with additives, treatments containing ammonium phosphate and EDTA had the lowest and highest concentrations of heavy metals, respectively. Concentrations of these metals in treatments without plants were higher than those with plants. Conclusion Increasing of soil pH is effective on stabilization of heavy metals in soil. Ammonium phosphate plays an important role in stabilizing and EDTA and ammonium citrate increase the mobility of lead, zinc and cadmium in soil and groundwater.

  13. Coagulation-flocculation in leachate treatment using modified micro sand

    Science.gov (United States)

    Thaldiri, Nur Hanani; Halim, Azhar Abdul

    2013-11-01

    Sanitary landfill leachate is considered as highly polluted wastewater, without any treatment, discharging into water system will cause underground water and surface water pollutions. This study was to investigate the treatability of the semi-aerobic landfill leachate via coagulation-flocculation using poly-aluminum chloride (PAC), cationic polymer, and modified micro sand. Leachate was collected from Pulau Burung Sanitary Landfill (PBSL) located in Penang, Malaysia. Coagulation-flocculation was performed by using jar test equipment and the effect of pH, dose of coagulant and dose of polymer toward removal of chemical oxygen demand (COD), color and suspended solid (SS) were examined. Micro sand was also used in this study to compare settling time of coagulation-flocculation process. The optimum pH, dose of coagulant (PAC) and dose of polymer (cationic) achieved were 7.0, 1000 mg/L and 8 mg/L, respectively. The dose of micro sand used for the settling time process was 300 mg/L. Results showed that 52.66% removal of COD, 97.16% removal of SS and 96.44% removal of color were achieved under optimum condition. The settling times for the settling down of the sludge or particles that formed during coagulation-flocculation process were 1 min with modified sand, 20 min with raw micro sand and 45 min without micro sand.

  14. Biogeochemistry and isotope geochemistry of a landfill leachate plume.

    Science.gov (United States)

    van Breukelen, Boris M; Röling, Wilfred F M; Groen, Jacobus; Griffioen, Jasper; van Verseveld, Henk W

    2003-09-01

    The biogeochemical processes were identified which improved the leachate composition in the flow direction of a landfill leachate plume (Banisveld, The Netherlands). Groundwater observation wells were placed at specific locations after delineating the leachate plume using geophysical tests to map subsurface conductivity. Redox processes were determined using the distribution of solid and soluble redox species, hydrogen concentrations, concentration of dissolved gases (N(2), Ar, and CH(4)), and stable isotopes (delta15N-NO(3), delta34S-SO(4), delta13C-CH(4), delta2H-CH(4), and delta13C of dissolved organic and inorganic carbon (DOC and DIC, respectively)). The combined application of these techniques improved the redox interpretation considerably. Dissolved organic carbon (DOC) decreased downstream in association with increasing delta13C-DOC values confirming the occurrence of degradation. Degradation of DOC was coupled to iron reduction inside the plume, while denitrification could be an important redox process at the top fringe of the plume. Stable carbon and hydrogen isotope signatures of methane indicated that methane was formed inside the landfill and not in the plume. Total gas pressure exceeded hydrostatic pressure in the plume, and methane seems subject to degassing. Quantitative proof for DOC degradation under iron-reducing conditions could only be obtained if the geochemical processes cation exchange and precipitation of carbonate minerals (siderite and calcite) were considered and incorporated in an inverse geochemical model of the plume. Simulation of delta13C-DIC confirmed that precipitation of carbonate minerals happened.

  15. Domestic wells have high probability of pumping septic tank leachate

    Directory of Open Access Journals (Sweden)

    J. E. Bremer

    2012-08-01

    Full Text Available Onsite wastewater treatment systems are common in rural and semi-rural areas around the world; in the US, about 25–30% of households are served by a septic (onsite wastewater treatment system, and many property owners also operate their own domestic well nearby. Site-specific conditions and local groundwater flow are often ignored when installing septic systems and wells. In areas with small lots (thus high spatial septic system densities, shallow domestic wells are prone to contamination by septic system leachate. Mass balance approaches have been used to determine a maximum septic system density that would prevent contamination of groundwater resources. In this study, a source area model based on detailed groundwater flow and transport modeling is applied for a stochastic analysis of domestic well contamination by septic leachate. Specifically, we determine the probability that a source area overlaps with a septic system drainfield as a function of aquifer properties, septic system density and drainfield size. We show that high spatial septic system density poses a high probability of pumping septic system leachate. The hydraulic conductivity of the aquifer has a strong influence on the intersection probability. We find that mass balance calculations applied on a regional scale underestimate the contamination risk of individual drinking water wells by septic systems. This is particularly relevant for contaminants released at high concentrations, for substances that experience limited attenuation, and those that are harmful even at low concentrations (e.g., pathogens.

  16. Household hazardous waste in municipal landfills: contaminants in leachate.

    Science.gov (United States)

    Slack, R J; Gronow, J R; Voulvoulis, N

    2005-01-20

    Household hazardous waste (HHW) includes waste from a number of household products such as paint, garden pesticides, pharmaceuticals, photographic chemicals, certain detergents, personal care products, fluorescent tubes, waste oil, heavy metal-containing batteries, wood treated with dangerous substances, waste electronic and electrical equipment and discarded CFC-containing equipment. Data on the amounts of HHW discarded are very limited and are hampered by insufficient definitions of what constitutes HHW. Consequently, the risks associated with the disposal of HHW to landfill have not been fully elucidated. This work has focused on the assessment of data concerning the presence of hazardous chemicals in leachates as evidence of the disposal of HHW in municipal landfills. Evidence is sought from a number of sources on the occurrence in landfill leachates of hazardous components (heavy metals and xenobiotic organic compounds [XOC]) from household products and the possible disposal-to-emissions pathways occurring within landfills. This review demonstrates that a broad range of xenobiotic compounds occurring in leachate can be linked to HHW but further work is required to assess whether such compounds pose a risk to the environment and human health as a result of leakage/seepage or through treatment and discharge.

  17. Genotoxicity of Pesticide Waste Contaminated Soil and Its Leachate

    Institute of Scientific and Technical Information of China (English)

    S. D. SIVANESAN; K. KRISHNAMURTHI; S. D. WACHASUNDER; T. CHAKRABARTI

    2004-01-01

    Improper land disposal of hazardous waste can result in leaching of hazardous constituents which may contaminate ground and surface water leading to adverse impact on human health and environment consequences. The present study utilized mammalian cell culture for the genotoxicity assessment of waste and its leachate. Methods Genotoxic potential and chemical analysis of pesticide derived tarry waste contaminated soil extract and its leachate was assessed using in vitro human lymphocyte cultures and GC-MS. Results The investigation revealed that the soil extract could cause significant to highly significant genotoxicity in the form of DNA strand break at 25 μL (P<0.01), 50 μL, 100 μL and 200 μL (P<0.001) and chromosomal aberration at 25 μL (P<0.01) and 50 μL and 100 μL (P<0.001). The leachate could cause significant DNA strand break and chromosomal aberration only at 100 μL and 200 μL (P<0.01) dose levels. Conclusion The genotoxicity observed is attributed to carbaril and tetra methyl naphthyl carbamate, the major ingredients of the extracts, as revealed by GC-MS.

  18. Fresh Kills leachate treatment and minimization study: Volume 2, Modeling, monitoring and evaluation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fillos, J.; Khanbilvardi, R.

    1993-09-01

    The New York City Department of Sanitation is developing a comprehensive landfill leachate management plan for the Fresh Kills landfill, located on the western shore of Staten Island, New York. The 3000-acre facility, owned and operated by the City of New York, has been developed into four distinct mounds that correspond to areas designated as Sections 1/9, 2/8, 3/4 and 6/7. In developing a comprehensive leachate management plan, the estimating leachate flow rates is important in designing appropriate treatment alternatives to reduce the offsite migration that pollutes both surface water and groundwater resources.Estimating the leachate flow rates from Sections 1/9 and 6/7 was given priority using an available model, hydrologic evaluation of landfill performance (HELP), and a new model, flow investigation for landfill leachate (FILL). The field-scale analysis for leachate flow included data collection of the leachate mound-level from piezometers and monitoring wells installed on-site, for six months period. From the leachate mound-head contours and flow-gradients, Leachate flow rates were computed using Darcy`s Law.

  19. Leachate formation and characteristics from gasification and grate incineration bottom ash under landfill conditions.

    Science.gov (United States)

    Sivula, Leena; Sormunen, Kai; Rintala, Jukka

    2012-04-01

    Characteristics and formation of leachates from waste gasification and grate firing bottom ash were studied using continuous field measurements from 112 m(3) lysimeters embedded into landfill body for three years. In addition, the total element concentrations of the fresh ash were analysed and laboratory batch tests were performed to study leachate composition. The three-year continuous flow measurement showed that about one fifth of the leachates were formed, when the flow rate was >200 l/d, covering 13) major part of the study. In the grate ash leachate pH was lower (landfill conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Design validation and performance of closed loop gas recirculation system

    Science.gov (United States)

    Kalmani, S. D.; Joshi, A. V.; Majumder, G.; Mondal, N. K.; Shinde, R. R.

    2016-11-01

    A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m2, with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C2H2F4), isobutane (iC4H10) and sulphur hexafluoride (SF6) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.

  1. Designing and Testing of Self-Cleaning Recirculating Zebrafish Tanks.

    Science.gov (United States)

    Nema, Shubham; Bhargava, Yogesh

    2016-08-01

    Maintenance of large number of zebrafish in captive conditions is a daunting task. This can be eased by the use of recirculating racks with self-cleaning zebrafish tanks. Commercially available systems are costly, and compatibility of intercompany products has never been investigated. Although various cost-effective designs and methods of construction of custom-made recirculating zebrafish racks are available in literature, the design of self-cleaning zebrafish tanks is still not available. In this study, we report the design and method of construction of the self-cleaning unit, which can be fitted in any zebrafish tank. We validated the design by investigating sediment cleaning process in rectangular and cylindrical tank geometries using time lapse imaging. Our results suggest that for both tank geometries, the tanks fitted with self-cleaning unit provided superior sediment cleaning than the tanks fitted with overflow-drain unit. Although the self-cleaning unit could clean the sediment completely from both geometries over prolonged period, the cleaning of sediments was faster in the cylindrical tank than the rectangular tank. In conclusion, cost and efforts of zebrafish maintenance could be significantly reduced through the installation of our self-cleaning unit in any custom-made zebrafish tank.

  2. CONVECTIVE HEAT TRANSFER IN CYCLONE DEVICE WITH EXTERNAL GAS RECIRCULATION

    Directory of Open Access Journals (Sweden)

    S. V. Karpov

    2016-01-01

    Full Text Available The article considers the convective heat transfer on the surface of a hollow cylinder or several billets in a cyclone device with the new principle of external gas recirculation. According to this principle, transport of coolant from the lateral surface of the chamber, where the temperature is the highest, in the axial region is being fulfilled due to the pressure drop between the wall and axial areas of cyclonic flow. Dependency analysis of average and local heat transfer coefficients from operational and geometrical parameters has been performed; the generalized similarity equations for the calculation of the latter have been suggested. It is demonstrated that in case of download of a cyclone chamber with several billets, the use of the considered scheme of the external recirculation due to the specific characteristics of aerodynamics practically does not lead to noticeable changes in the intensity of convective heat transfer. Both experimental data and the numerical simulation results obtained with the use of OpenFOAM platform were used in the work. The investigations fulfilled will expand the area of the use of cyclone heating devices.

  3. Continuous hydroponic wheat production using a recirculating system

    Science.gov (United States)

    Mackowiak, C. L.; Owens, L. P.; Hinkle, C. R.; Prince, R. P.

    1989-01-01

    Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems.

  4. Economic evaluation of recirculation as a method of pile cooling

    Energy Technology Data Exchange (ETDEWEB)

    Carson, A.B.; Purcell, R.H.; McEwen, L.H.

    1954-04-07

    Reductions in irradiation costs and increases in production rate have provided a continuing incentive for more efficient operation of the Hanford Piles. These improvements have been obtained by means of higher specific powers, greater water flow rates, and better water utilization. However, the extent of the improvements which can be made in this manner may be limited by such factors as tube and slug corrosion, slug stability, and graphite damage rates at higher operating temperatures. Water purification and pumping costs are also factors to be considered. New slug designs are being developed which may be capable of much higher specific power operation. Higher graphite temperatures may also prove feasible, but the water plant performance limitations for the present single pass cooling systems may prove much more expensive to relieve. The use of recirculating cooling water as a means of attaining higher temperature, higher power operation has received preliminary study. A preliminary economic evaluation of an operating area equipped for recirculation versus single pass cooling is needed to better determine the relative merits of the two cooling methods. This report presents the results of such an evaluation and discusses the direction of future development work in the field of pile cooling.

  5. A high temperature granulation process for ecological ash recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Sundqvist, Thomas

    1999-07-01

    This thesis is a summary of three papers dealing with new technologies for facilitating ecological biomass ash recirculation back to forest and farm lands. The present outtake of biomass for paper and energy production may be incompatible with a sustainable forestry. The cycle of nutrients contained in the biomass extracted must be closed by ash recirculation in an environmental compatible way. This implies stabilization of the loose ashes/rest-products to a product with low heavy metal contents, controlled leaching properties and a high spreadability. In the present work, two different techniques were evaluated for the possibilities to separate heavy metals from the nutrient elements by utilizing high process temperatures to vaporize the unwanted metals from the condensed bulk materials. The results indicated that direct in-situ separation in fluidized bed combustion systems is possible, but requires too high process temperatures to be practically attractive. On the other hand, the new proposed high temperature treatment method for granulated raw materials was found to significantly separate As, Cd and Pb, with separation efficiencies exceeding 90 % at optimal operating conditions. In addition, the results indicated that the treatment method could be used to significantly delay and control the leaching characteristics, as well as the content of products of incomplete combustion of the produced granules.

  6. Turbulent characteristics of shear-thinning fluids in recirculating flows

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.S. [Inst. Superior de Engenharia do Porto (Portugal). Dept. de Engenharia Quimica; Pinho, F.T. [Centro de Estudos de Fenomenos de Transporte, Departamento de Engenharia Mecanica e Gestao Industrial, Faculdade de Engenharia da Universidade do Porto, Rua dos Bragas, 4050-123 Porto (Portugal)

    2000-03-01

    A miniaturised fibre optic laser-Doppler anemometer was used to carry out a detailed hydrodynamic investigation of the flow downstream of a sudden expansion with 0.1-0.2% by weight shear-thinning aqueous solutions of xanthan gum. Upstream of the sudden expansion the pipe flow was fully-developed and the xanthan gum solutions exhibited drag reduction with corresponding lower radial and tangential normal Reynolds stresses, but higher axial Reynolds stress near the wall and a flatter axial mean velocity profile in comparison with Newtonian flow. The recirculation bubble length was reduced by more than 20% relative to the high Reynolds number Newtonian flow, and this was attributed to the occurrence further upstream of high turbulence for the non-Newtonian solutions, because of advection of turbulence and earlier high turbulence production in the shear layer. Comparisons with the measurements of Escudier and Smith (1999) with similar fluids emphasized the dominating role of inlet turbulence. The present was less anisotropic, and had lower maximum axial Reynolds stresses (by 16%) but higher radial turbulence (20%) than theirs. They reported considerably longer recirculating bubble lengths than we do for similar non-Newtonian fluids and Reynolds numbers. (orig.)

  7. Integrated characterisation of aquifer heterogeneity and landfill leachate plume migration

    Science.gov (United States)

    Tremblay, L.; Lefebvre, R.; Gloaguen, E.; Paradis, D.

    2009-05-01

    The understanding of groundwater flow and contaminant migration is based on our ability to characterize aquifers and represent these processes with numerical simulators. This understanding is required to efficiently remediate contaminated sites since the failure of remediation actions are often related to an insufficient understanding of aquifer heterogeneity. During the last decades, continuous development of numerical simulators allowed models to better represent complex flow systems. However, conventional hydrogeological characterization methods do not provide the data required to define aquifer heterogeneity. An original hydrogeological characterization approach was used to define aquifer heterogeneity and delineate landfill leachate plumes through the use and integration of varied techniques. The objective of the study is to develop a methodology to integrate hydrogeological, geophysical and geochemical data using geostatistical tools. The characterization program aims to better characterize the aquifer, delineate leachate plumes emitted by a former landfill, and guide a study of the natural attenuation of the plumes. The initial phase of the integrated multidisciplinary aquifer characterization program was carried out in a 12 km2 area of the sub-watershed surrounding the landfill of St-Lambert-de-Lauzon, Québec. In the study area, a 10-m thick sandy unconfined aquifer overlies clayey silt and till layers. In this relatively flat area, natural streams as well as agricultural and forestry drainage networks control groundwater flow. The first phase of the project focused on a regional hydrogeological and geochemical characterization where 5 field methods were combined: 1) surface geophysics (ground penetrating radar and electrical tomography) (GPR); 2) direct-push methods including a) cone penetration tests (CPT), b) soil sampling and c) installation of full- screened observation wells; 3) multilevel measurement of geochemical parameters and groundwater

  8. Landfill leachate as a mirror of today's disposable society: Pharmaceuticals and other contaminants of emerging concern in final leachate from landfills in the conterminous United States

    Science.gov (United States)

    Masoner, Jason R.; Kolpin, Dana W.; Furlong, Edward T.; Cozzarelli, Isabelle M.; Gray, James L.

    2015-01-01

    Final leachates (leachate after storage or treatment processes) from 22 landfills in 12 states were analyzed for 190 pharmaceuticals and other contaminants of emerging concern (CECs), which were detected in every sample, with the number of CECs ranging from 1 to 58 (median = 22). In total, 101 different CECs were detected in leachate samples, including 43 prescription pharmaceuticals, 22 industrial chemicals, 15 household chemicals, 12 nonprescription pharmaceuticals, 5 steroid hormones, and 4 animal/plant sterols. The most frequently detected CECs were lidocaine (91%, local anesthetic), cotinine (86%, nicotine degradate), carisoprodol (82%, muscle relaxant), bisphenol A (77%, component of plastics and thermal paper), carbamazepine (77%, anticonvulsant), and N,N-diethyltoluamide (68%, insect repellent). Concentrations of CECs spanned 7 orders of magnitude, ranging from 2.0 ng/L (estrone) to 17 200 000 ng/L (bisphenol A). Concentrations of household and industrial chemicals were the greatest (∼1000-1 000 000 ng/L), followed by plant/animal sterols (∼1000-100 000 ng/L), nonprescription pharmaceuticals (∼100-10 000 ng/L), prescription pharmaceuticals (∼10-10 000 ng/L), and steroid hormones (∼10-100 ng/L). The CEC concentrations in leachate from active landfills were significantly greater than those in leachate from closed, unlined landfills (p = 0.05). The CEC concentrations were significantly greater (p modern lined landfills than in leachate released to groundwater from closed, unlined landfills (p = 0.04). The CEC concentrations were significantly greater (p = 0.06) in the fresh leachate (leachate before storage or treatment) reported in a previous study compared with the final leachate sampled for the present study.

  9. Coastal recirculation potential affecting air pollutants in Portugal: The role of circulation weather types

    Science.gov (United States)

    Russo, Ana; Gouveia, Célia; Levy, Ilan; Dayan, Uri; Jerez, Sonia; Mendes, Manuel; Trigo, Ricardo

    2016-06-01

    Coastal zones are under increasing development and experience air pollution episodes regularly. These episodes are often related to peaks in local emissions from industry or transportation, but can also be associated with regional transport from neighbour urban areas influenced by land-sea breeze recirculation. This study intends to analyze the relation between circulation weather patterns, air mass recirculation and pollution levels in three coastal airsheds of Portugal (Lisbon, Porto and Sines) based on the application of an objective quantitative measure of potential recirculation. Although ventilation events have a dominant presence throughout the studied 9-yrs period on all the three airsheds, recirculation and stagnation conditions occur frequently. The association between NO2, SO2 and O3 levels and recirculation potential is evident during summer months. Under high average recirculation potential and high variability, NO2 and SO2 levels are higher for the three airsheds, whilst for O3 each airshed responds differently. This indicates a high heterogeneity among the three airsheds in (1) the type of emission - traffic or industry - prevailing for each contaminant, and (2) the response to the various circulation weather patterns and recirculation situations. Irrespectively of that, the proposed methodology, based on iterative K-means clustering, allows to identify which prevailing patterns are associated with high recirculation potential, having the advantage of being applicable to any geographical location.

  10. Unit process engineering for water quality control and biosecurity in marine water recirculating systems

    Science.gov (United States)

    High-intensity systems that treat and recirculate water must maintain a culture environment that can sustain near optimum fish health and growth at the design carrying capacity. Water recirculating systems that use centralized treatment systems can benefit from the economies of scale to decrease th...

  11. Low Load Model of a Once-through Boiler with Recirculation

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    2006-01-01

    A dynamic simulation model of a once-through boiler in low to medium load is developed. When the system is in low load, water from the evaporator is recirculated through a bottle. This recirculation system is included in the model, which is then shown to fit closed-loop data from a real plant...

  12. The efficiency of different phenol-degrading bacteria and activated sludges in detoxification of phenolic leachates.

    Science.gov (United States)

    Kahru, A; Reiman, R; Rätsep, A

    1998-07-01

    Phenolic composition, toxicity and biodegradability of three different phenolic leachates/samples was studied. Samples A and C were the leachates from the oil-shale industry spent shale dumps at Kohtla-Järve, Estonia. Sample B was a laboratory-prepared synthetic mixture of 7 phenolic compounds mimmicking the phenolic composition of the leachate A. Toxicity of these 3 samples was analyzed using two photobacterial test (BioTox and Microtox), Daphnia test (DAPHTOXKIT F pulex) and rotifiers' test (ROTOXKIT F). All the LC50 values were in the range of 1-10%, leachate A being the most toxic. The growth and detoxifying potential (toxicity of the growth medium was measured using photobacterial tests) of 3 different phenol-utilizing bacteria and acclimated activated sludges was studied in shake-flask cultures. 30% leachate A (altogether 0.6 mM total phenolic compounds) was too toxic to rhodococci and they did not grow. Cell number of Kurthia sp. and Pseudomonas sp. in 30% leachate A increased by 2 orders of magnitude but despite of the growth of bacteria the toxicity of the leachate did not decrease even by 7 weeks of cultivation. However, if the activated sludge was used instead of pure bacterial cultures the toxicity of the 30% leachate A was eliminated already after 3 days of incubation. 30% samples B and C were detoxified by activated sludge even more rapidly, within 2 days. As the biodegradable part of samples A and B should be identical, the detoxification of leachate A compared to that of sample B was most probably inhibited by inorganic (e.g. sulphuric) compounds present in the leachate A. Also, the presence of toxic recalcitrant organic compounds in the leachate A (missed by chemical analysis) that were not readily biodegradable even by activated sludge consortium should not be excluded.

  13. Removal of polycyclic aromatic hydrocarbons (PAH) during anaerobic digestion with recirculation of ozonated digested sludge

    Energy Technology Data Exchange (ETDEWEB)

    Bernal-Martinez, Arodi; Patureau, Dominique; Delgenes, Jean-Philippe [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F11100 (France); Carrere, Helene [INRA, UR 050, Laboratoire de Biotechnologie de l' Environnement, Avenue des Etangs, Narbonne F11100 (France)], E-mail: carrere@supagro.inra.fr

    2009-03-15

    PAH are particularly monitored because of their carcinogenic properties and their ubiquity in the environment. Their presence in municipal sewage sludge is a major problem due to the environmental risks associated with the sludge spreading on agricultural soils. The objective of this work was to asses the removal of PAH naturally present in sludge by continuous anaerobic digestion with recirculation of ozonated sludge. Recirculation of ozonated digested sludge allowed to enhance PAH removals, the highest efficiency was obtained with the highest ozone dose (0.11 g O{sub 3}/g{sub TS}). In order to study the effect of recirculation, a reactor was operated without recirculation but was fed with a mixture of raw and ozonated digested sludge. This process led to the best performances in terms of PAH and solid removals. This pointed out some accumulation of nonbiodegradable or recalcitrant compounds during recirculation assay. Smallest and most soluble compounds presented the highest biodegradation efficiencies.

  14. Pulsed-focusing recirculating linacs for muon acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland [Muons, Inc., Batavia, IL (United States)

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

  15. Performance model of a recirculating stack nickel hydrogen cell

    Science.gov (United States)

    Zimmerman, Albert H.

    1994-01-01

    A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for

  16. Recirculation, stagnation and ventilation: The 2014 legionella episode

    Science.gov (United States)

    Russo, Ana; Soares, Pedro M. M.; Gouveia, Célia M.; Cardoso, Rita M.; Trigo, Ricardo M.

    2017-04-01

    Legionella transmission through the atmosphere is unusual, but not unprecedented. A scientific paper published in 2006 reports a surge in Pas-de-Calais, France, in which 86 people have been infected by bacteria released by a cooling tower more than 6 km away [3]. Similarly, in Norway, in 2005, there was another case where contamination spread beyond 10 km, although more concentrated within a radius of 1 km from an industrial unit [2]. An unprecedented large Legionella outbreak occurred in November 2014 nearby Lisbon, Portugal. As of 7 November 2014, 375 individuals become hill and 12 died infected by the Legionella pneumophila bacteria, contracted by inhalation of steam droplets of contaminated water (aerosols). These droplets are so small that can carry the bacteria directly to the lungs, depositing it in the alveoli. One way of studying the propagation of legionella episodes is through the use of aerosol dispersion models. However, such approaches often require detailed 3D high resolution wind data over the region, which isn't often available for long periods. The likely impact of wind on legionella transmission can also be understood based on the analysis of special types of flow conditions such as stagnation, recirculation and ventilation [1, 4]. The Allwine and Whiteman (AW) approach constitutes a straightforward method to assess the assimilative and dispersal capacities of different airsheds [1,4], as it only requires hourly wind components. Thus, it has the advantage of not needing surface and upper air meteorological observations and a previous knowledge of the atmospheric transport and dispersion conditions. The objective of this study is to analyze if the legionella outbreak event which took place in November 2014 had extreme potential recirculation and/or stagnation characteristics. In order to accomplish the proposed objective, the AW approach was applied for a hindcast time-series covering the affected area (1989-2007) and then for an independent

  17. PULSED-FOCUSING RECIRCULATING LINACS FOR MUON ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland PAUL

    2014-12-31

    Since the muon has a short lifetime, fast acceleration is essential for high-energy applications such as muon colliders, Higgs factories, or neutrino factories. The best one can do is to make a linear accelerator with the highest possible accelerating gradient to make the accelerating time as short as possible. However, the cost of such a single linear accelerator is prohibitively large due to expensive power sources, cavities, tunnels, and related infrastructure. As was demonstrated in the Thomas Jefferson Accelerator Facility (Jefferson Lab) Continuous Electron Beam Accelerator Facility (CEBAF), an elegant solution to reduce cost is to use magnetic return arcs to recirculate the beam through the accelerating RF cavities many times, where they gain energy on each pass. In such a Recirculating Linear Accelerator (RLA), the magnetic focusing strength diminishes as the beam energy increases in a conventional linac that has constant strength quadrupoles. After some number of passes the focusing strength is insufficient to keep the beam from going unstable and being lost. In this project, the use of fast pulsed quadrupoles in the linac sections was considered for stronger focusing as a function of time to allow more successive passes of a muon beam in a recirculating linear accelerator. In one simulation, it was shown that the number of passes could be increased from 8 to 12 using pulsed magnet designs that have been developed and tested. This could reduce the cost of linac sections of a muon RLA by 8/12, where more improvement is still possible. The expense of a greater number of passes and corresponding number of return arcs was also addressed in this project by exploring the use of ramped or FFAG-style magnets in the return arcs. A better solution, invented in this project, is to use combined-function dipole-quadrupole magnets to simultaneously transport two beams of different energies through one magnet string to reduce costs of return arcs by almost a factor of

  18. Sanguinarine non- versus re-circulation during isolated heart perfusion--a Jekyll and Hyde effect?

    Science.gov (United States)

    Webster, I; Smith, A; Lochner, A; Huisamen, B

    2014-10-01

    In isolated rat heart perfusion experiments, drug administration occurs via retrograde perfusion. This can be done in the non-recirculating mode (coronary effluent is discarded), or recirculating mode (coronary effluent is collected and reused). It was recently observed in our lab while using sanguinarine, an MKP-1 inhibitor, that there were differences in outcomes depending on the mode of recirculation used. Hearts from control (C); diet-induced obese (DIO) Wistar rats and their age matched controls (AMC) were perfused on the rig. Hearts received buffer (control) , insulin, sanguinarine, insulin + sanguinarine combination or methanol (vehicle) for 15 mins pre- and 10 mins post-ischemia in either a non- or re-circulating manner. Hearts were subjected to 15 mins global ischemia and 30 mins reperfusion. Mechanical function was documented pre- and post-ischemia . When not-recirculated , sanguinarine alone and in combination with insulin in C, DIO and AMC groups, caused a significant decrease in functional recovery during reperfusion. However, when the coronary effluent was recirculated, hearts perfused with sanguinarine or sanguinarine + insulin exhibited a significant recovery in function when compared with their non-recirculation counterparts (p < 0.01). No differences were seen with either control, insulin nor vehicle hearts. Sanguinarine elicited a vast improvement in perfusion outcomes when recirculated compared to non-recirculation . Since this was seen during perfusion only when sanguinarine was present, it is possible that recirculating reperfusion of the drug caused profound changes in its composition. More investigation is needed into the mechanisms involved. Thus caution should be exercised by researchers when designing a perfusion protocol for drug research.

  19. Capture of CO2 From Recirculating Flue Gas Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Ochs, Thomas L.

    2003-01-01

    The possible need for an economical method for the separation of CO2 from flue gas adds a new set of challenges to power plant design, construction, operation, and maintenance. Many of the new requirements of CO2 separation are similar in nature to those addressed by the mature chemical engineering processes used in petroleum refining and industrial chemical production. Chemical engineering processes are regularly used to separate heterogeneous vapors in processes such as the fractionation of hydrocarbons or the separation of the components of air. This paper addresses the application of chemical engineering processes to the mixtures of gases and vapors found in the flue gas of recirculating boilers. Adaptation of these techniques can lead to a reduction in the energy required to capture CO2.

  20. Fuzzy Logic Controller based on geothermal recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Hanaa M. Farghally

    2014-01-01

    Full Text Available One of the most common uses of geothermal heat is in recirculation aquaculture systems (RAS where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and brazed heat exchanger to be used with geothermal energy as a source of heating water. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon – NTU analysis method. For optimal growth and abundance of production, a Fuzzy Logic control (FLC system is applied to control the water temperature (29 °C. A FLC system has several advantages over conventional techniques; relatively simple, fast, adaptive, and its response is better and faster at all atmospheric conditions. Finally, the total system is built in MATLAB/SIMULINK to study the overall performance of control unit.

  1. Experiments With Recirculating Target for F-18 Production

    Science.gov (United States)

    Kiselev, M. Y.

    2003-08-01

    Approximately 10 ml of O-18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F-18 in relation to consumed O-18 water material. It can also increase productivity by eliminating idle periods for re-filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target.

  2. Numerical investigation of recirculation in the UTSI MHD combustor

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, R.J.; Lee, J.J.; Giel, T.V. Jr.

    1983-09-01

    Numerical studies were carried out to investigate the gross structure of flow in cylindrical combustors. The combustor configurations studied are variations of a working design used at the University of Tennessee Space Institute to burn pulverized coal at temperatures in excess of 3000K for generation of a plasma feeding a magnetohydrodynamic channel. The numerical studies were conducted for an isothermal fluid; the main objective of the calculations was to study the effect of the oxidant injection pattern on the gross structure of recirculating flows within the combustor. The calculations illustrate the basic features of the flow in combustors of this type and suggest implications for the injection of coal and oxidizer in this type of combustor.

  3. Dynamics of microorganism populations in recirculating nutrient solutions

    Science.gov (United States)

    Strayer, R. F.

    1994-11-01

    This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

  4. Exergetic performance analysis of a recirculating aquaculture system

    Energy Technology Data Exchange (ETDEWEB)

    Kucuk, Haydar [Mechanical Engineering Department, Guemueshane University, 29000 Guemueshane (Turkey); Midilli, Adnan [Energy Division, Mechanical Engineering Department. Nigde University, 51000 Nigde (Turkey); Oezdemir, Atilla; Cakmak, Eyuep [Central Fisheries Research Institute, Ministry of Agricultural and Rural Affairs, Trabzon (Turkey); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ont. (Canada)

    2010-05-15

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period. (author)

  5. Characterization of microalgae-bacteria consortium cultured in landfill leachate for carbon fixation and lipid production.

    Science.gov (United States)

    Zhao, Xin; Zhou, Yan; Huang, Sheng; Qiu, Duanyang; Schideman, Lance; Chai, Xiaoli; Zhao, Youcai

    2014-03-01

    The characteristics of cultivating high-density microalgae-bacteria consortium with landfill leachate was tested in this study. Landfill leachate was collected from Laogang landfill operated for over 10 years in Shanghai, China. The maximum biomass concentration of 1.58g L(-1) and chlorophyll a level of 22mg L(-1) were obtained in 10% leachate spike ratio. Meanwhile, up to 90% of the total nitrogen in landfill leachate was removed in culture with 10% leachate spike ratio with a total nitrogen concentration of 221.6mg L(-1). The fluorescence peak of humic-like organic matters red shifted to longer wavelengths by the end of culture, indicating that microalgae-bacteria consortium was effective for treating landfill leachate contaminants. Furthermore, with the leachate spike ratio of 10%, the maximum lipid productivity and carbon fixation were 24.1 and 65.8mg L(-1)d(-1), respectively. Results of this research provide valuable information for optimizing microalgae culture in landfill leachate.

  6. 40 CFR 761.357 - Reporting the results of the procedure used to simulate leachate generation.

    Science.gov (United States)

    2010-07-01

    ... simulate leachate generation as micrograms PCBs per liter of extract from a 100 gram sample of dry bulk... used to simulate leachate generation. 761.357 Section 761.357 Protection of Environment ENVIRONMENTAL..., PROCESSING, DISTRIBUTION IN COMMERCE, AND USE PROHIBITIONS Sampling Non-Liquid, Non-Metal PCB Bulk...

  7. Physiological responses of Vetiver plant (Vetiver zizanioides to municipal waste leachate

    Directory of Open Access Journals (Sweden)

    Sasan Mohsenzadeh

    2016-06-01

    Full Text Available Vetiver plant is tolerant to acidity and temperature variations. Has rapid growth for biomass production and has high tolerance to organic and non-organic compounds in municipal waste leachate for example heavy metals. So this plant is good for landfill cultivation. In this study, physiological responses to municipal waste leachate were studied. Statistical design was a randomized complete block and each block treated with different concentrations of latex at levels of zero, 15, 30, 45 and 60 percent compared to the original latex waste. The leachate collected from the Shiraz landfill and brought into the greenhouse. The physiological characterization including leaf area, dry weight, chlorophyll, anthocyanin, proline, soluble sugars and total protein were measured. The result indicated that the dry weight, chlorophyll and anthocyanin decrease with increasing of latex concentration. The leaf area, leaf relative water, soluble sugars and total protein increased with increasing latex concentration. Proline concentration at 15 percent of leachate increased significantly compared to controls, whereas at higher concentrations decreased. According to the results, it is recommended that 45 percent of leachate in a landfill can be used to irrigate Vetiver. This is the maximum concentration of leachate that Vetiver plant can survive as green space. Primary filtration of leachate before using is recommended. If the aim is more growth or perfume application from root, less concentration of leachate is better.

  8. Effect and Cost Research for Leachate Treatment in PAC/Fenton and Fenton/PAC Technology

    Institute of Scientific and Technical Information of China (English)

    JIANG Bao-jun; YIN Jun; WU Xiao-yan; Zhao Yu-xin

    2010-01-01

    To compare the treatment effects and the costs of coagulation/Fenton process and Fenton/coagulation process in leachate treatment,fresh and old leachates were respestively treated with these two techniques.The experimental results indicate that the highest chemical oxygen demand(COD)removal rate of Fenton reaction on leachate can be acquired under the conditions of pH = 3.5,nH2O2/nFe2+= 6,mH2O2/mCOD = 3,and reaction time = 4 h.Polyaluminium chloride(PAC)coagulation has the highest COD removal rate on leachate under the condition of mPAC/mCOD = 0.6.Under the optimum reaction conditions,coagulation/Fenton and Fenton/coagulation processes were respestively adopted to treat raw leachate.The data also show that COD removal rate of coagulation/Fenton process on fresh and old leachates are90.56% and 86.52% respectively and that of Fenton/coagulation process 89.99% and 85.99%,so there is no obvious difference.But the cost of coagulation/Fenton process for leachate treatment is RMB 62.6,lower than that of Fenton/coagulation process.Therefore,coagulation/Fenton process is more optimized than Fenton/coagulation process for leachate treatment.

  9. Oral bioavailability and enterohepatic recirculation of otilonium bromide in rats.

    Science.gov (United States)

    Shin, Beom Soo; Kim, Jung Jun; Kim, John; Hu, Sul Ki; Kim, Hyoung Jun; Hong, Seok Hyun; Kim, Han Kyung; Lee, Hye Suk; Yoo, Sun Dong

    2008-01-01

    This study was conducted to examine the oral bioavailability and the possibility of enterohepatic recirculation of otilonium bromide in rats. A sensitive LC/MS/MS assay (LLOQ 0.5 ng/mL) was developed for the determination of otilonium and applied to i.v. and oral administration studies in bile duct cannulated (BDC) and non-BDC rats. After i.v. injection to BDC rats (1 mg/ kg as otilonium), average t(1/2), CL, Vz and AUC were 7.9 +/- 1.9 h, 8.7 +/- 3.1 mL/min/kg, 5.7 +/- 1.4 L/kg and 2,088 +/- 676 ng h/mL, respectively, and these values were comparable to those found in non-BDC rats. The percentages of i.v. dose excreted unchanged in bile and urine in BDC rats were 11.6 +/- 3.0 and 3.1 +/- 0.7%, respectively. Upon oral administration to non-BDC rats (20 mg/kg as otilonium), t(1/2), Cmax, Tmax and AUC were 6.4 +/- 1.3 h, 182.8 +/- 44.6 ng/mL, 1.9 +/- 1.6 h and 579 +/- 113 ng h/mL, respectively. The absolute oral bioavailability was low (1.1%), while the drug was preferentially distributed to gastrointestinal tissues. A secondary peak was observed in the serum concentration-time profiles in non-BDC rats following both i.v. and oral administration, indicating that otilonium bromide was subject to enterohepatic recirculation.

  10. Recirculation of the Canary Current in fall 2014

    Science.gov (United States)

    Hernández-Guerra, Alonso; Espino-Falcón, Elisabet; Vélez-Belchí, Pedro; Dolores Pérez-Hernández, M.; Martínez-Marrero, Antonio; Cana, Luis

    2017-10-01

    Hydrographic measurements together with Ship mounted Acoustic Doppler Current Profilers and Lowered Acoustic Doppler Current Profilers (LADCP) obtained in October 2014 are used to describe water masses, geostrophic circulation and mass transport of the Canary Current System, as the Eastern Boundary of the North Atlantic Subtropical Gyre. Geostrophic velocities are adjusted to velocities from LADCP data to estimate an initial velocity at the reference layer. The adjustment results in a northward circulation at the thermocline layers over the African slope from an initial convergent flow. Final reference velocities and consequently absolute circulation are estimated from an inverse box model applied to an ocean divided into 13 neutral density layers. This allows us to evaluate mass fluxes consistent with the thermal wind equation and mass conservation. Ekman transport is estimated from the wind data derived from the Weather Research and Forecasting model. Ekman transport is added to the first layer and adjusted with the inverse model. The Canary Current located west of Lanzarote Island transports to the south a mass of - 1.5 ± 0.7 Sv (1 Sv = 106 m3 s- 1 ≈ 109 kg s- 1) of North Atlantic Central Water at the surface and thermocline layers ( 0-700 m). In fall 2014, hydrographic data shows that the Canary Current in the thermocline (below at about 80 m depth to 700 m) recirculates to the north over the African slope and flows through the Lanzarote Passage. At intermediate layers ( 700-1400 m), the Intermediate Poleward Undercurrent transports northward a relatively fresh Antarctic Intermediate Water in the range of 0.8 ± 0.4 Sv through the Lanzarote Passage and west of Lanzarote Island beneath the recirculation of the Canary Current.

  11. Removal of toxic metals during biological treatment of landfill leachates.

    Science.gov (United States)

    Robinson, T

    2017-05-01

    Progressive implementation of the European Water Framework Directive has resulted in substantial changes in limits for discharges of heavy metals both to watercourses, and to sewer. The objective of this paper is to provide original, real, full-scale data obtained for removal of metals during aerobic biological leachate treatment, and also to report on studies carried out to look at further trace metal removal. Polishing technologies examined and investigated include; the incorporation of ultrafiltration (UF) membranes into biological treatment systems, the use of ion exchange, and of activated carbon polishing processes. Ultrafiltration was able to provide a 60 percent reduction in COD values in treated leachates, compared with COD values found in settled/clarified effluents. Removal rates for COD varied from 30.5 to 79.8 percent. Additionally, ultrafiltration of treated leachates significantly reduced both chromium and nickel concentrations of effluents by 61.6% and 34.3% respectively (median values). Despite mean reductions of chromium (9.7%) and nickel (13.7%) noted during the ion exchange trials, these results would not justify use of this technology for metals removal at full-scale. Further preliminary studies used pulverized activated carbon (PAC) polishing of UF effluents to demonstrate that significant (up to 80 per cent) removal of COD, TOC and heavy metals could readily be achieved by doses of up to 10g/l of suitable activated carbons. Additional evidence is provided that many trace metals are present not in ionic form, but as organic complexes; this is likely to make their removal to low levels more difficult and expensive. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Control factors of partial nitritation for landfill leachate treatment

    Institute of Scientific and Technical Information of China (English)

    LIANG Zhu; LIU Jun-xin

    2007-01-01

    Anaerobic ammonium oxidation (ANAMMOX) technology has potential technical superiority and economical efficiency for the nitrogen removal from landfill leachate, which contains high-strength ammonium nitrogen (NH4+-N) and refractory organics. To complete the ANAMMOX process, a preceding partial nitritation step to produce the appropriate ratio of nitrite/ammonium is a key stage. The objective of this study was to determine the optimal conditions to acquire constant partial nitritation for landfill leachate treatment, and a bench scale fixed bed bio-film reactor was used in this study to investigate the effects of the running factors on the partial nitritation. The results showed that both the dissolved oxygen (DO) concentration and the ammonium volumetric loading rate (Nv) had effects on the partial nitritation. In the controlling conditions with a temperature of 30±1℃, Nv of 0.2-1.0 kg NH4+-N/(m3·d), and DO concentration of 0.8-2.3 mg/L, the steady partial nitritation was achieved as follows: more than 94% partial nitritation efficiency (nitrite as the main product), 60%-74% NH4+-N removal efficiency, and NO2--N/NH4+-N ratio (concentration ratio) of 1.0-1.4 in the effluent.The impact of temperature was related to Nv at certain DO concentration, and the temperature range of 25-30℃ was suitable for treating high strength ammonium leachate. Ammonium-oxidizing bacteria (AOB) could be acclimated to higher FA (free ammonium) in the range of 122-224 mg/L. According to the denaturing gradient gel electrophoresis analysis result of the bio-film in the reactor, there were 25 kinds of 16S rRNA gene fragments, which indicated that abundant microbial communities existed in the bio-film, although high concentrations of ammonium and FA may inhibit the growth of the nitrite-oxidizing bacteria (NOB) and other microorganisms in the reactor.

  13. Transformation of metals speciation in a combined landfill leachate treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yanyu [College of Environmental Science and Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China); Key Laboratory of Environmental Protection and Eco-remediation of Guangdong Regular Higher Education Institutions, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China); Zhou Shaoqi, E-mail: fesqzhou@scut.edu.cn [College of Environmental Science and Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China); State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Environmental Protection and Eco-remediation of Guangdong Regular Higher Education Institutions, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China); Chen Dongyu; Zhao Rong; Li Huosheng; Lin Yiming [College of Environmental Science and Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China); Key Laboratory of Environmental Protection and Eco-remediation of Guangdong Regular Higher Education Institutions, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006 (China)

    2011-04-01

    Landfill leachate was treated by a combined sequential batch reactor (SBR), coagulation, Fenton oxidation and biological aerated filter (BAF) technology. The metals in treatment process were fractionated into three fractions: particulate and colloidal (size charge filtration), free ion/labile (cation exchange) and non-labile fractions. Fifty percent to 66% Cu, Ni, Zn, Mn, Pb and Cd were present as particulate/colloidal matter in raw leachate, whereas Cr was present 94.9% as non-labile complexes. The free ion/labile fractions of Ni, Zn, Mg, Mn, Pb and Cd increased significantly after treatment except Cr. Fifty-nine percent to 100% of Al was present mainly as particulate/colloidal matter > 0.45 {mu}m and the remaining portions were predicted as non-labile complexes except in coagulation effluent. The speciation of Fe varied significantly in various individual processes. Visual MINTEQ simulation showed that 95-100% colloidal species for Cu, Cd and Pb were present as metal-humic complexes even with the lower dissolved organic carbon. Optimum agreements for the free ion/labile species were within acidic solution, whereas under-estimated in alkaline effluents. Overestimated particulate/colloidal fraction consisted with the hypothesis that a portion of colloids in fraction < 0.45 {mu}m were considered as dissolved. - Research Highlights: {yields} Metals in various landfill leachate treatments were size charge fractionated and the speciation transformations were compared. {yields} Species predictions of metals were simulated by Visual MINTEQ model. {yields} Optimum agreements for the free ion/labile species were within acidic solution. {yields} Predictions of colloidal species agree with experimental data well in alkaline solution.

  14. Environmental impact of leachate characteristics on water quality.

    Science.gov (United States)

    Cumar, Sampath Kumar Mandyam; Nagaraja, Balasubramanya

    2011-07-01

    Improper urbanization and industrialization are causing a critical stress on groundwater quality in urban areas of the developing countries. The present study under investigation describes the pollution caused by leachate from a waste management site in southwestern Bangalore city causing pollution of the surface water and groundwater reserves. The characterization of 20 groundwater samples and Haralukunte lake sample indicated high pollution of these water reserves by leachate entry into the groundwater and surface water sources. The study area focuses around the solid waste management site, carrying out bio-composting and vermi-composting of municipal solid waste. Further investigations on the severe health problems faced by the public in the study area has revealed a clear pointer towards the usage of polluted water for rearing live-stock, farming, and domestic activities. The characterization of the leachate with high values of BOD at 1,450 mg/l, TDS at 17,200 mg/l, nitrates at 240 mg/l, and MPN at 545/100 ml indicates a clear nuisance potential, which has been substantiated by the characterization of lake water sample with chlorides at 3,400 mg/l, TDS at 8,020 mg/l, and lead and cadmium at 0.18 and 0.08 mg/l, respectively. Analysis of groundwater samples shows alarming physicochemical values closer to the waste disposal site and relatively reduced values away from the source of the waste management site. Bureau of Indian Standards have been adapted as the benchmark for the analysis and validation of observed water quality criteria.

  15. Treatment of landfill leachate using a solar destillar

    Directory of Open Access Journals (Sweden)

    José Fernando Thomé Jucá

    2012-04-01

    Full Text Available The subject of this research was to build, develop, evaluate and optimize a system of natural evaporation of leachate, to reduce the organic loads. Physical and chemical microbiological parameters were monitored during the experiment to evaluate the system performance. The solar radiation and rainfall influence on the evaporator was investigated. The results showed 100% reduction of the turbidity, color and total solids. The values of BOD, COD, thermotolerants and total coliforms in the treated effluent had concentrations that meet the Brazilian Federal Environmental Council (CONAMA standards. Based on the results, it was concluded that the natural solar system was adequate for small landfills.

  16. Managing the leachate at the regional landfill in Kikinda

    Directory of Open Access Journals (Sweden)

    Marković Sanja

    2016-01-01

    Full Text Available In developed, industrial countries, there is 1.2kg waste per capita, waste being collected and disposed of in regulated, sanitary landfills, which have systems for the protection of groundwater and air from pollutants, in Serbia, the largest number of landfills does not meet even the basic safety criteria for environmental protection. Several municipalities in Serbia began with the organization of the regional waste management system and within that frame, the construction of regional landfills which meet European standards in terms of environmental protection. The paper presents a method of management and use of leachate at the regional waste landfill 'ASA', Kikinda.

  17. Groundwater and Leachate Monitoring and Sampling at ERDF, CY 2010

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, R. L.; Lawrence, B. L.

    2011-06-09

    The purpose of this annual monitoring report is to evaluate the conditions of and identify trends for groundwater beneath the ERDF and report leachate results in fulfillment of the requirements specified in the ERDF ROD2 and the ERDF Amended ROD (EPA 1999). The overall objective of the groundwater monitoring program is to determine whether ERDF has impacted the groundwater. This objective is complicated by the fact that the ERDF is situated downgradient of the numerous groundwater contamination plumes originating from the 200 West Area.

  18. Municipal sludge leachate-induced genotoxicity in mice--a subacute study.

    Science.gov (United States)

    Tewari, Anamika; Chauhan, L K S; Kumar, Dinesh; Gupta, S K

    2005-11-10

    Inappropriate disposal of municipal sludge (MS) results in the leaching of toxic metals and organic chemicals, which can contaminate the surface and ground water leading to the serious health hazards. In this study, the genotoxic potential of the leachate prepared from MS sample was examined in mouse bone marrow cells through chromosomal aberrations (CA), micronucleus test (MT) and comet assay. Analysis of metals and physicochemical parameters of the leachate was also carried out to correlate the genotoxic results. The dried sludge showed high concentrations of heavy metals, viz. Cr, Cu, Pb and Ni. However, in 10% leachate, concentrations of these metals were manifold lower than that of obtained in dried sludge. Male mice orally gavaged to leachates (0.1-0.4 ml/mouse/day) for 15 days revealed significant (Peffect was observed to be dose-dependent. Treatment of mice with leachates also induced significant (Pgenotoxic effects in mammals and suggest risks in human population.

  19. Parametric Analysis of Leachate and Water Resources around Municipal Solid Waste Landfill area in Solan

    Directory of Open Access Journals (Sweden)

    Sharma Deepika

    2016-01-01

    Full Text Available Leachate is defined as the liquid that drains from the landfill. The paper presents the physico-chemical, bacteriological and heavy metal testing results carried out for leachate, surface and sub-surface water samples collected from municipal solid waste landfill and different water sources in Solan to find out the effect of leachate percolation on groundwater quality. Physico-chemical parameters analysed were, pH, Total Dissolve Solid (TDS, sulphate, turbidity, Electrical Conductivity (EC while biological parameters tested were Biological Oxygen Demand (BOD, Chemical Oxygen Demand (COD, Most Probable Number (MPN test and ammonical nitrogen. Testing for heavy metals (Pb, Zn, Cr, Ni, Fe were carried out and have been reported. The results reveal that the leachate from the unlined landfill may have a significant impact on the groundwater resource (often used as drinking source particularly because of the toxic nature of the leachate coupled with the soil characteristics which is permeable in nature.

  20. Development Study of Turbulent Kappa-Epsilon Model for Recirculation flow III : Two Dimension Recirculation Flow in a Reservoir

    Directory of Open Access Journals (Sweden)

    M. Syahril B. Kusuma

    2009-05-01

    Full Text Available An assessment of recirculation flow in Jatiluhur reservoir is conducted based on two dimensions turbulent K-e model. The numerical model was developed using finite difference method where hydrodynamic equation was solved by the combination of Mc Cormack and splitting methods. The K-e equation is solved using quickest scheme in convection term, central scheme in diffusion term and Euler scheme in reaction term. The simulations were done for maximum incoming flow during the rainy season and the dry season. Model results for the rainy season case have shown good agreement with those found by field measurement. The rainy season case generated a much recirculted flow and higher concentration of DO in the reservoir than that of the dry season case. Denser grid and high courant number is needed to avoid it from becoming oscillating and unstable and for achieving a more accurate results for the case with less average velocity.

  1. Influence of Landfill Operation and Tropical Seasonal Variation on Leachate Characteristics: Results from Lysimeter Experiment

    Directory of Open Access Journals (Sweden)

    Islam M. Rafizul

    2012-01-01

    Full Text Available This study demonstrates the influence of lysimeter operational condition and tropical seasonal variation of leachate characteristics generated from municipal solid waste (MSW deposited in landfill lysimeter at KUET campus, Bangladesh. Three different situations of landfill were considered here as well as both the open dump lysimeter-A having a base liner and sanitary landfill lysimeter-B and C at two different types of cap liner were simulated. The leachate characteristics, leachate generation and climatic influence parameter had been continually monitored, from June 2008 to May 2010. This period covers both dry and rainy season. The leachate generation followed the rainfall pattern and the open dump lysimeter-A without top cover was recorded to have the highest leachate generation. Moreover, the open dump lysimeter-A had lower concentration and load of total kjeldahl nitrogen (TKN, ammonia nitrogen (NH4-N and dissolved organic carbon (DOC, while chemical oxygen demand (COD and biological oxygen demand (BOD5 concentration were higher compared with sanitary lysimeter-B and C. On the other hand, sanitary lysimeter-B, not only had lowest leachate generation, but also produced reasonably low COD and BOD5 concentration compared with open dump lysimeter-A. Based on evaluated results, it was also concluded that metal concentrations which were comparatively higher in leachate of open dump lysimeter were Ca and K, however, the heavy metal concentrations of Cd, Cu, Zn and Mn, and those apparently lower were metals of Na, Mg and Fe as well as heavy metals of Cr, Pb and Ni. However, significant release of heavy metals under open dump lysimeter was observed compared to sanitary lysimeter. Moreover, meaningful correlation between DOC and leaching of Cu and Pb was observed. Result reveals that lysimeter operational mode had direct effect on leachate quality. Finally, it can be concluded that the knowledge of leachate quality will be useful in planning and

  2. Sulfur recirculation for increased electricity production in Waste-to-Energy plants.

    Science.gov (United States)

    Andersson, Sven; Blomqvist, Evalena W; Bäfver, Linda; Jones, Frida; Davidsson, Kent; Froitzheim, Jan; Karlsson, Martin; Larsson, Erik; Liske, Jesper

    2014-01-01

    Sulfur recirculation is a new technology for reducing boiler corrosion and dioxin formation. It was demonstrated in full-scale tests at a Waste to Energy plant in Göteborg (Sweden) during nearly two months of operation. Sulfur was recirculated as sulfuric acid from the flue gas cleaning back to the boiler, thus creating a sulfur loop. The new technology was evaluated by extensive measurement campaigns during operation under normal conditions (reference case) and operation with sulfur recirculation. The chlorine content of both fly ash and boiler ash decreased and the sulfur content increased during the sulfur recirculation tests. The deposit growth and the particle concentration decreased with sulfur recirculation and the dioxin concentration (I-TEQ) of the flue gas was reduced by approximately 25%. Sulfuric acid dew point measurements showed that the sulfuric acid dosage did not lead to elevated SO3 concentrations, which may otherwise induce low temperature corrosion. In the sulfur recirculation corrosion probe exposures, the corrosion rate decreased for all tested materials (16Mo3, Sanicro 28 and Inconel 625) and material temperatures (450 °C and 525 °C) compared to the reference exposure. The corrosion rates were reduced by 60-90%. Sulfur recirculation prevented the formation of transition metal chlorides at the metal/oxide interface, formation of chromate and reduced the presence of zinc in the corrosion products. Furthermore, measured corrosion rates at 525 °C with sulfur recirculation in operation were similar or lower compared to those measured at 450 °C material temperature in reference conditions, which corresponds to normal operation at normal steam temperatures. This implies that sulfur recirculation allows for higher steam data and electricity production without increasing corrosion.

  3. The BIOZO process--a biofilm system combined with ozonation: occurrence of xenobiotic organic micro-pollutants in and removal of polycyclic aromatic hydrocarbons and nitrogen from landfill leachate.

    Science.gov (United States)

    Plósz, Benedek G Y; Vogelsang, Christian; Macrae, Kenneth; Heiaas, Harald H; Lopez, Antonio; Liltved, Helge; Langford, Katherine H

    2010-01-01

    We present an assessment of xenobiotic organic micro-pollutants (XOM) occurrence and removal of polycyclic aromatic hydrocarbons (PAHs) in a novel biofilm system combined with ozonation, the BIOZO concept, treating partly stabilised landfill leachate. A novel, staged moving-bed biofilm reactor (SMBBR) design was implemented in laboratory- and pilot-scale, and the PAHs removal efficiency of controlled ozonation was assessed installing the ozonation step in the nitrate recirculation line (Position 1) or between the pre-anoxic and aerobic zones (Position 2). COD removal in a laboratory- and in a pilot-scale SMBBR system with and without ozonation is additionally addressed. Results obtained in a screening study (GC-ToF-MS) were used to compile a priority list of XOMs in leachate based on relative occurrence, showing PAHs as the predominant fraction. Biological treatment is shown to be an effective means to remove PAHs detected in the aqueous phase. PAH removal takes in most part place in the pre-anoxic zone, thereby decreasing toxicity exhibited by PAH on autotrophic nitrifier bacteria in the aerobic zone. Ozonation installed in Position 2 is shown to be superior over Position I in terms of COD, PAH and nitrogen removal efficiencies. We additionally demonstrate the potential of intermittent sludge ozonation as a means to decrease PAH concentrations in sludge wasted and to improve nitrogen removal in the BIOZO system.

  4. Optimization of electrocoagulation process for the treatment of landfill leachate

    Science.gov (United States)

    Huda, N.; Raman, A. A.; Ramesh, S.

    2017-06-01

    The main problem of landfill leachate is its diverse composition comprising of persistent organic pollutants (POPs) which must be removed before being discharge into the environment. In this study, the treatment of leachate using electrocoagulation (EC) was investigated. Iron was used as both the anode and cathode. Response surface methodology was used for experimental design and to study the effects of operational parameters. Central Composite Design was used to study the effects of initial pH, inter-electrode distance, and electrolyte concentration on color, and COD removals. The process could remove up to 84 % color and 49.5 % COD. The experimental data was fitted onto second order polynomial equations. All three factors were found to be significantly affect the color removal. On the other hand, electrolyte concentration was the most significant parameter affecting the COD removal. Numerical optimization was conducted to obtain the optimum process performance. Further work will be conducted towards integrating EC with other wastewater treatment processes such as electro-Fenton.

  5. Occurrence and prevalence of antibiotic resistance in landfill leachate.

    Science.gov (United States)

    Wang, Yangqing; Tang, Wei; Qiao, Jing; Song, Liyan

    2015-08-01

    Antibiotic resistance (AR) is extensively present in various environments, posing emerging threat to public and environmental health. Landfill receives unused and unwanted antibiotics through household waste and AR within waste (e.g., activated sludge and illegal clinical waste) and is supposed to serve as an important AR reservoir. In this study, we used culture-dependent methods and quantitative molecular techniques to detect and quantify antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in 12 landfill leachate samples from six geographic different landfills, China. Five tested ARGs (tetO, tetW, bla(TEM), sulI, and sulII) and seven kinds of antibiotic-resistant heterotrophic ARB were extensively detected in all samples, demonstrating their occurrence in landfill. The detected high ratio (10(-2) to 10(-5)) of ARGs to 16S ribosomal RNA (rRNA) gene copies implied that ARGs are prevalent in landfill. Correlation analysis showed that ARGs (tetO, tetW, sulI, and sulII) significantly correlated to ambient bacterial 16S rRNA gene copies, suggesting that the abundance of bacteria in landfill leachate may play an important role in the horizontal spread of ARGs.

  6. Reverse osmosis and nanofiltration of biologically treated leachate.

    Science.gov (United States)

    Kuusik, Aare; Pachel, Karin; Kuusik, Argo; Loigu, Enn; Tang, Walter Z

    2014-01-01

    Experiments of nano-filtration (NF) and reverse osmosis (RO) were conducted to remove most pollutants from the biological treated leachate. For example, the purified permeate after reverse osmosis treatment with spiral membranes reached effluent water quality as follows: COD of 57 mg O2/l, BOD7 of 35 mg O2/l, and suspended solid of 1 mg/l which satisfies the discharge standards in Estonia. For both RO and NF, conductivity can be reduced by 91% from 6.06 to 0.371 mS/cm by RO and 99% from 200 to 1 mS/cm by NF. To test the service life of the RO spiral membranes, the process was able to reduce chemical oxygen demand (COD) and biological oxygen demand (BOD) of biologically treated leachate by 97.9% and 93.2% even after 328 and 586 hours, respectively. However, only 39.0% and 21.7% reductions of Ptot and Ntot were achieved. As a result, neither RO (spiral membranes process) nor NF was able to reduce the total nitrogen (TN) to the required discharge limit of 15 mg/l.

  7. Anaerobic methane oxidation in a landfill-leachate plume.

    Science.gov (United States)

    Grossman, Ethan L; Cifuentes, Luis A; Cozzarelli, Isabelle M

    2002-06-01

    The alluvial aquifer adjacent to Norman Landfill, OK, provides an excellent natural laboratory for the study of anaerobic processes impacting landfill-leachate contaminated aquifers. We collected groundwaters from a transect of seven multilevel wells ranging in depth from 1.3 to 11 m that were oriented parallel to the flow path. The center of the leachate plume was characterized by (1) high alkalinity and elevated concentrations of total dissolved organic carbon, reduced iron, and methane, and (2) negligible oxygen, nitrate, and sulfate concentrations. Methane concentrations and stable carbon isotope (delta13C) values suggest anaerobic methane oxidation was occurring within the plume and at its margins. Methane delta13C values increased from about -54 per thousand near the source to > -10 per thousand downgradient and at the plume margins. The isotopic fractionation associated with this methane oxidation was -13.6+/-1.0 per thousand. Methane 13C enrichment indicated that 80-90% of the original landfill methane was oxidized over the 210-m transect. First-order rate constants ranged from 0.06 to 0.23 per year, and oxidation rates ranged from 18 to 230 microM/y. Overall, hydrochemical data suggest that a sulfate reducer-methanogen consortium may mediate this methane oxidation. These results demonstrate that natural attenuation through anaerobic methane oxidation can be an important sink for landfill methane in aquifer systems.

  8. Novel and Conventional Technologies for Landfill Leachates Treatment: A Review

    Directory of Open Access Journals (Sweden)

    Vincenzo Torretta

    2016-12-01

    Full Text Available Municipal solid waste final disposal represents an environmental burden worldwide since landfilling, or open dumping, is still the preferred solution for the end of life of solid discarded materials. This study aims to review the technological innovations applied for landfill leachate treatment, taking into consideration the experiences obtained during the past years and the solutions which have been implemented. The review showed that both biological and physiochemical treatments are not able to achieve the requested water quality level, according to the limits established by regulations, whether applied in a single treatment or multiple treatments. In order to respect sustainable release limits to guarantee environmental protection, the construction of depuration systems and combining biological and physiochemical treatment methods is considered of the utmost importance. The review looks at possible joint applications of different treatment techniques reviewed by other studies and considers the state of the art of current research. Combined technical solutions suggested within the 2016 peer-reviewed papers are presented and discussed as a sustainable way to effectively treat landfill leachate, giving particular attention to feasible solutions for developing countries.

  9. Transformation of metals speciation in a combined landfill leachate treatment.

    Science.gov (United States)

    Wu, Yanyu; Zhou, Shaoqi; Chen, Dongyu; Zhao, Rong; Li, Huosheng; Lin, Yiming

    2011-04-01

    Landfill leachate was treated by a combined sequential batch reactor (SBR), coagulation, Fenton oxidation and biological aerated filter (BAF) technology. The metals in treatment process were fractionated into three fractions: particulate and colloidal (size charge filtration), free ion/labile (cation exchange) and non-labile fractions. Fifty percent to 66% Cu, Ni, Zn, Mn, Pb and Cd were present as particulate/colloidal matter in raw leachate, whereas Cr was present 94.9% as non-labile complexes. The free ion/labile fractions of Ni, Zn, Mg, Mn, Pb and Cd increased significantly after treatment except Cr. Fifty-nine percent to 100% of Al was present mainly as particulate/colloidal matter >0.45 μm and the remaining portions were predicted as non-labile complexes except in coagulation effluent. The speciation of Fe varied significantly in various individual processes. Visual MINTEQ simulation showed that 95-100% colloidal species for Cu, Cd and Pb were present as metal-humic complexes even with the lower dissolved organic carbon. Optimum agreements for the free ion/labile species were within acidic solution, whereas under-estimated in alkaline effluents. Overestimated particulate/colloidal fraction consisted with the hypothesis that a portion of colloids in fraction <0.45 μm were considered as dissolved.

  10. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.

    2010-01-01

    Repetitive long term formalin application at low dose was investigated to determine the effect on formaldehyde removal rate, biofilter nitrification and the microbial composition in small-scale recirculation aquaculture biofilters. Six pilot-scale recirculation aquaculture systems holding rainbow...... Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since...

  11. Effect of Inoculation with Effective Microorganisms and Leachate Recycle on Degradation of Municipal Refuse

    Institute of Scientific and Technical Information of China (English)

    沈东升; 何若; 朱荫湄

    2004-01-01

    Biodegradation of waste in landfill is a slow process requiring decades for completion. Accelerated degradation of municipal refuse in modulated landfill environments may alleviate or eliminate pollution to the land, water and air. In this work, nineteen effective microorganisms (EMs) were isolated from old landfill refuse by enrichment culturing techniques and used for the inoculum of municipal refuse. The preliminary experiments demonstrate that a combination of EMs inoculation in landfill with leachate recycle resulted in increased rates of decomposition and faster process stability. The concentrations of COD, VFA and SO42- in digester with EMs inoculation and leachate recycle decreased more rapidly than others. Gas production from digester with EMs inoculation and leachate recycle commenced around 32 days, which is a week shorter than with leachate recycle only. And peak cumulative gas production was obtained much earlier in digester with EMs inoculation and leachate recycle (150 days) compared to 180 days with leachate recycle only. Moreover, in the first two months, the rate of settlement in digester with EMs inoculation and leachate recycle was more rapid than others.

  12. Fertilizer efficiency and environmental risk of irrigating Impatiens with composting leachate in decentralized solid waste management.

    Science.gov (United States)

    Zhou, Chuanbin; Wang, Rusong; Zhang, Yishan

    2010-06-01

    The reduction and reuse of composting leachate is an issue of importance in the field of decentralized solid waste management. In this study, composting leachate from source-separated food waste was treated and subsequently used as liquid fertilizer to irrigate Impatiens (Impatiens balsamina). The leachate was altered by adjusting storage time and dilution, and through addition of microbial inocula. For each test case, the effects of irrigation were monitored by analyzing the Impatiens extension degree, numbers of leaves and flowers, dry weight, and photosynthetic pigment content to assess fertilizer efficiency. The main results obtained revealed that the addition of microbial inocula and lengthening of storage times may lower COD concentrations, adjust pH value and maintain a comparatively high level of nutrient contents. By adding microbial inocula, a COD concentration of 9.6% and BOD(5) concentration of 6.7% were obtained for non-treated leachate with the same storage time. COD concentrations in leachate decreased to 69.4% after 36weeks storage. Moreover, composting leachate promoted growth of Impatiens. The dry weight biomass of Impatiens irrigated using treated diluted leachate was 1.15-2.94 times that obtained for Impatiens irrigated using tap water. Lastly, following the irrigation of Impatiens over a short period, soil did not accumulate VOCs and heavy metals to levels exceeding relative standards. Further research on heavy metal and salinity accumulation in plants should be undertaken to meet the needs of large-scale applications.

  13. Toxicological evaluation of landfill leachate using plant (Allium cepa) and fish (Leporinus obtusidens) bioassays.

    Science.gov (United States)

    Klauck, Cláudia Regina; Rodrigues, Marco Antonio Siqueira; da Silva, Luciano Basso

    2013-11-01

    The disposal of municipal waste in landfills may pose an environmental problem because the product of the decomposition of these residues generates large volumes of leachate, which may present high toxicity. The aim of this study was to assess the toxic and genotoxic effects of a sample of untreated leachate in fish (Leporinus obtusidens) and onions (Allium cepa). The leachate was collected in a landfill located in the region of Vale do Rio dos Sinos, southern Brazil. The fish were exposed to raw leachate, at concentrations of 0.5%, 1.0%, 5%, 10% and 20% for 6 days, while the bulbs of A. cepa were exposed to concentrations of 5%, 10%, 25%, 50% and 100% for 48 h. For fish, the concentrations of 5%, 10% and 20% were lethal, thus indicating high toxicity; however, sublethal concentrations (0.5% and 1.0%) showed no genotoxicity by micronucleus test when compared with the control group. In the bioassays involving onions, high toxicity was observed, with significant reduction of root growth and mitotic index in bulbs exposed to the 100% concentration of the leachate. An increase in the frequency of chromosome abnormalities in the A. cepa root cells in anaphase-telophase was observed in accordance with the increase in the concentration of leachate (5%, 10%, 25% and 50%), with values significantly greater than the control, at the highest concentration. The results showed that the leachate contains toxic and genotoxic substances, thus representing a major source of environmental pollution if not handled properly.

  14. Evaluation of Cajanus cajan (pigeon pea) for phytoremediation of landfill leachate containing chromium and lead.

    Science.gov (United States)

    Jerez Ch, José A; Romero, Rosaura M

    2016-11-01

    Landfill leachates containing heavy metals are important contaminants and a matter of great concern due to the effect that they might have on ecosystems. We evaluated the use of Cajanus cajan to remove chromium and lead from landfill leachates. Eight-week-old plants were submitted to varied tests to select the experimental conditions. Water assays with a solution (pH 6) containing leachate (25% v/v) were selected; the metals were added as potassium dichromate and lead (II) nitrate salts. Soil matrices that contained leachate (30% v/v) up to field capacity were used. For both water and soil assays, the metal concentrations were 10 mg kg(-1). C. cajan proved able to remove 49% of chromium and 36% of lead, both from dilute leachate. The plants also removed 34.7% of chromium from irrigated soil, but were unable to decrease the lead content. Removal of nitrogen from landfill leachate was also tested, resulting in elimination of 85% of ammonia and 70% of combined nitrite/nitrate species. The results indicate that C. cajan might be an effective candidate for the rhizofiltration of leachates containing chromium and lead, and nitrogen in large concentrations.

  15. Municipal Leachate Treatment by Fenton Process: Effect of Some Variable and Kinetics

    Directory of Open Access Journals (Sweden)

    Mohammad Ahmadian

    2013-01-01

    Full Text Available Due to complex composition of leachate, the comprehensive leachate treatment methods have been not demonstrated. Moreover, the improper management of leachate can lead to many environmental problems. The aim of this study was application of Fenton process for decreasing the major pollutants of landfill leachate on Kermanshah city. The leachate was collected from Kermanshah landfill site and treated by Fenton process. The effect of various parameters including solution pH, Fe2+ and H2O2 dosage, Fe2+/H2O2 molar ratio, and reaction time was investigated. The result showed that with increasing Fe2+ and H2O2 dosage, Fe2+/H2O2 molar ratio, and reaction time, the COD, TOC, TSS, and color removal increased. The maximum COD, TOC, TSS, and color removal were obtained at low pH (pH: 3. The kinetic data were analyzed in term of zero-order, first-order, and second-order expressions. First-order kinetic model described the removal of COD, TOC, TSS, and color from leachate better than two other kinetic models. In spite of extremely difficulty of leachate treatment, the previous results seem rather encouraging on the application of Fenton’s oxidation.

  16. Heavy metal binding capacity (HMBC) of municipal solid waste landfill leachates.

    Science.gov (United States)

    Ward, Marnie L; Bitton, Gabriel; Townsend, Timothy

    2005-07-01

    This research describes the use of a toxicity assay for the identification of metal toxicity, bioavailability and heavy metal binding capacity (HMBC) of municipal solid waste (MSW) landfill leachates. MetPLATE, an assay specific for heavy metal toxicity, was used to determine the HMBC of MSW leachates collected from 14 sites in Florida, with a wide range of chemical and physical characteristics. The leachates displayed a low toxicity which was attributed to the site-specific parameters, including, high concentrations of both organic and inorganic ligands. The HMBC test was undertaken to measure the effect of these site-specific parameters on metal toxicity. The potential for MSW leachate to bind and, thus, detoxify heavy metals was investigated with copper, zinc, and mercury. The HMBC values obtained ranged from 3 to 115, 5 to 93 and 4 to 101 for HMBC-Cu+2, HMBC-Zn+2, and HMBC-Hg+2, respectively. Additionally, the high strength leachates displayed the highest binding capacities, although the landfills sampled represented a wide range of characteristics. For comparison, the HMBC values reported with local lake water, Lake Alice and Lake Beverly, and a wastewater treatment plant effluent were all below 3. A partial fractionation of MSW leachate samples from sites 1, 5 and 8, was conducted to further investigate the influence of selected site-specific physico-chemical parameters on metal binding. The fractionation revealed that the HMBC of the leachate samples was heavily influenced by the concentration of solids, organics and hardness.

  17. Impact of pine needle leachates from a mountain pine beetle infested watershed on groundwater geochemistry

    Science.gov (United States)

    Pryhoda, M.; Sitchler, A.; Dickenson, E.

    2013-12-01

    The mountain pine beetle (MPB) epidemic in the northwestern United States is a recent indicator of climate change; having an impact on the lodgepole pine forest ecosystem productivity. Pine needle color can be used to predict the stage of a MPB infestation, as they change color from a healthy green, to red, to gray as the tree dies. Physical processes including precipitation and snowfall can cause leaching of pine needles in all infestation stages. Understanding the evolution of leachate chemistry through the stages of MPB infestation will allow for better prediction of the impact of MPBs on groundwater geochemistry, including a potential increase in soil metal mobilization and potential increases in disinfection byproduct precursor compounds. This study uses batch experiments to determine the leachate chemistry of pine needles from trees in four stages of MPB infestation from Summit County, CO, a watershed currently experiencing the MPB epidemic. Each stage of pine needles undergoes four subsequent leach periods in temperature-controlled DI water. The subsequent leaching method adds to the experiment by determining how leachate chemistry of each stage changes in relation to contact time with water. The leachate is analyzed for total organic carbon. Individual organic compounds present in the leachate are analyzed by UV absorption spectra, fluorescence spectrometry, high-pressure liquid chromatography for organic acid analysis, and size exclusion chromatography. Leachate chemistry results will be used to create a numerical model simulating reactions of the leachate with soil as it flows through to groundwater during precipitation and snowfall events.

  18. Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiaofeng; Zhu, Shuangyan; Zhong, Delai; Zhu, Jingping, E-mail: jpzhuhust@163.com; Liao, Li, E-mail: liaoli2003@126.com

    2014-11-15

    Highlights: • Anaerobic co-digestion strategy for food waste treatment at OLR 41.8 g VS/L. • A certain amount of raw leachate effectively relieved acidic inhibition. • The study showed that food waste was completely degraded. - Abstract: In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH{sub 4}–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded. We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production.

  19. Tracing solid waste leachate in groundwater using δ13 C from dissolved inorganic carbon.

    Science.gov (United States)

    Haarstad, Ketil; Mæhlum, Trond

    2013-01-01

    Tracers can be used to monitor emissions of leachate from landfills in order to detect hydrological pathways and to evaluate environmental pollution. We investigated the stable carbon isotope ratio (δ(13)C-Σ CO (2)) in dissolved inorganic carbon and tritium ((3)H) in water, in addition to the tracers of pollution commonly found in relatively high concentrations in leachate, such as chloride (Cl), organic matter (COD), nitrogen (total and NH(4)-N), iron (Fe), electrical conductivity (EC) and pH. The sampling was performed at seven landfills in the south-eastern part of Norway during a period of 5 years. The objective was to evaluate the potential for tracing leachate in the environment with emphasis on groundwater pollution. By measuring the δ(13)C-Σ CO (2) in leachates, groundwaters and surface waters, the influence of leachate can be identified. The value of δ(13)C-Σ CO (2) varied from-5.5 to 25.9 ‰ in leachate, from-25.4 to 14.7 ‰ in groundwater and from-19.7 to-13.1 ‰ in creeks. A comparison of the carbon isotope ratio with COD, EC and the concentrations of total and NH (4)-N, Cl and Fe showed that δ(13)C-Σ CO (2) is a good tracer for leachate due to higher sensitivity compared to other parameters. The mean concentrations of all the studied parameters were higher in the leachate samples; however, only the carbon isotope ratio showed significant differences between all the groups with strong and middle pollution and samples with low pollution, showing that it can be used as a convenient tracer for leachate in groundwater and surface water. The carbon isotope ratio showed strong correlation between nitrogen, EC and bicarbonate, but not with pH. Tritium was only sporadically found in measureable concentrations and is not considered as a suitable tracer at the sampled locations.

  20. Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests.

    Science.gov (United States)

    Mavakala, Bienvenu K; Le Faucheur, Séverine; Mulaji, Crispin K; Laffite, Amandine; Devarajan, Naresh; Biey, Emmanuel M; Giuliani, Gregory; Otamonga, Jean-Paul; Kabatusuila, Prosper; Mpiana, Pius T; Poté, John

    2016-09-01

    Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments.

  1. Longitudinal data analysis in support of functional stability concepts for leachate management at closed municipal landfills

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, Robert D., E-mail: rdg@uchicago.edu [Center for Health Statistics, University of Chicago, 5841 S. Maryland Avenue, Chicago, IL 60637 (United States); Morris, Jeremy W.F., E-mail: jmorris@geosyntec.com [Geosyntec Consultants, 10220 Old Columbia Road, Suite A, Columbia, MD 21046 (United States); Prucha, Christopher P., E-mail: cprucha@wm.com [Groundwater Protection Program, Waste Management, 1550 Balmer Road, Box 200, Model City, NY 14107 (United States); Caldwell, Michael D., E-mail: mcaldwell@wm.com [Groundwater Protection Program, Waste Management, 3623 Wilson Road, Humble, TX 77396 (United States); Staley, Bryan F., E-mail: BStaley@erefdn.org [Environmental Research and Education Foundation, 3301 Benson Drive, Suite 301, Raleigh, NC 27609 (United States)

    2014-09-15

    Highlights: • Longitudinal data analysis using a mixed-effects regression model. • Dataset consisted of a total of 1402 samples from 101 closed municipal landfills. • Target analytes and classes generally showed predictable degradation trends. • Validates historical studies focused on macro organic indicators such as BOD. • BOD can serve as “gateway” indicator for planning leachate management. - Abstract: Landfill functional stability provides a target that supports no environmental threat at the relevant point of exposure in the absence of active control systems. With respect to leachate management, this study investigates “gateway” indicators for functional stability in terms of the predictability of leachate characteristics, and thus potential threat to water quality posed by leachate emissions. Historical studies conducted on changes in municipal solid waste (MSW) leachate concentrations over time (longitudinal analysis) have concentrated on indicator compounds, primarily chemical oxygen demand (COD) and biochemical oxygen demand (BOD). However, validation of these studies using an expanded database and larger constituent sets has not been performed. This study evaluated leachate data using a mixed-effects regression model to determine the extent to which leachate constituent degradation can be predicted based on waste age or operational practices. The final dataset analyzed consisted of a total of 1402 samples from 101 MSW landfills. Results from the study indicated that all leachate constituents exhibit a decreasing trend with time in the post-closure period, with 16 of the 25 target analytes and aggregate classes exhibiting a statistically significant trend consistent with well-studied indicators such as BOD. Decreasing trends in BOD concentration after landfill closure can thus be considered representative of trends for many leachate constituents of concern.

  2. Characterization and treatment of Denizli landfill leachate using anaerobic hybrid/aerobic CSTR systems.

    Science.gov (United States)

    Ağdağ, Osman Nuri

    2011-01-01

    Leachate generated in municipal solid waste landfill contains large amounts of organic and inorganic contaminants. In the scope of the study, characterization and anaerobic/aerobic treatability of leachate from Denizli (Turkey) Sanitary Landfill were investigated. Time-based fluctuations in characteristics of leachate were monitored during a one-year period. In characterization study; chemical oxygen demand (COD), biochemical oxygen demand (BOD) dissolved oxygen, temperature, pH, alkalinity, volatile fatty acids, total nitrogen, NH4-N, BOD5/COD ratio, suspended solid, inert COD, anaerobic toxicity assay and heavy metals concentrations in leachate were monitored. Average COD, BOD and NH4-N concentration in leachate were measured as 18034 mg/l, 11504 mg/l and 454 mg/l, respectively. Generally, pollution parameters in leachate were higher in summer and relatively lower in winter due to dilution by precipitation. For treatment of leachate, two different reactors, namely anaerobic hybrid and aerobic completely stirred tank reactor (CSTR) having effective volumes of 17.7 and 10.5 litres, respectively, were used. After 41 days of start-up period, leachate was loaded to hybrid reactor at 10 different organic loading rates (OLRs). OLR was increased by increasing COD concentrations. COD removal efficiency of hybrid reactor was carried out at a maximum of 91%. A percentage of 96% of residual COD was removed in the aerobic reactor. NH4-N removal rate in CSTR was quite high. In addition, high methane content was obtained as 64% in the hybrid reactor. At the end of the study, after 170 operation days, it can be said that the hybrid reactor and CSTR were very effective for leachate treatment.

  3. Duckweed Lemna minor (Liliopsida, Lemnaceae) as a natural biofilter in brackish and fresh closed recirculating systems

    National Research Council Canada - National Science Library

    Tharwat S. Nashashibi; Mutaz A. Al-Qutob

    2012-01-01

    This study attempted to assess the potential use of common duckweed Lemna minor asnatural biofilter in brackish closed recirculating systems of 4 g/L salinity and to evaluate the effect ofsalinities...

  4. High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

    2007-04-17

    Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

  5. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  6. Considerations upon energetic efficiency of a recirculating aquatic system (RAS for super intensive fish culture

    Directory of Open Access Journals (Sweden)

    Petru David

    2009-04-01

    Full Text Available The efficiency of the aquaculture using recirculating systems depends on many factors among which the most important it is the energy consumption of the system. To assure a high levelenergy conservation in an aquatic recirculating system, the intensity of water recirculation must be maximized, but this leads to a increasing of the consumed energy for water circulation. That is why is required a rigorous analysis for the energetic consumption for a system of this type and establishment of optimum solutions to minimize the consumption. This paperwork presents a detailed analysis of the energy consumption for a recirculating aquatic system for fish breeding, as well as considerations and solutions for optimization of the energy consumption.

  7. Applying rotary jet heads for mixing and mass transfer in a forced recirculation tank reactor system

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Grotkjær, Thomas; Hummer, J.S.

    2003-01-01

    An approximation to an ideally mixed tank reactor can be obtained by vigorous stirring with mechanical mixers. For an aerated reactor the gas dispersion contributes to the mixing process. Mixing can also be achieved by recirculation of a portion of the liquid through either an internal...... or an external loop.In this study, we determine mixing times in water and CMC solutions and oxygen mass transfer coefficients in water for a tank reactor system where a small fraction of the total liquid volume is rapidly circulated through an external loop and injected through the nozzles of rotary jet heads...... at 1-9 bar gauge pressure into the bulk liquid. Liquid feed can be added to the bulk volume or it may be injected into the pressurized recirculation loop. Gas is always fed to the recirculation loop, and the heat of reaction is removed in a plate-type heat exchanger inserted in the recirculation loop...

  8. Dietary carbohydrate composition can change waste production and biofilter load in recirculating aquaculture systems

    NARCIS (Netherlands)

    Meriac, A.; Eding, E.H.; Schrama, J.W.; Kamstra, A.; Verreth, J.A.J.

    2014-01-01

    This study investigated the effect of dietary carbohydrate composition on the production, recovery and degradability of fecal waste from rainbow trout (Oncorhynchus mykiss) in recirculating aquaculture systems (RAS). Dietary carbohydrate composition was altered by substituting starch with non-starch

  9. Aircraft Recirculation Filter for Air-Quality and Incident Assessment

    Science.gov (United States)

    Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

    2015-01-01

    The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters. PMID:25641977

  10. Characteristics of soot formation and burnout in turbulent recirculating flames

    Energy Technology Data Exchange (ETDEWEB)

    Touati, A.

    1987-01-01

    The present study represents an investigation of the effect of fuel type, fuel stream heat content, nitrogen dilution, and air jet velocity on soot formation rates and particle burnout in a highly recirculating, turbulent-type flame. Soot particle size and flux measurements have been made using an optical probe based on a large angle ratioing technique to measure the intensity of forward scattered light from individual particles at two off-axis angles. Chemical analyses of soot samples have been made using a gas chromatograph with a flame ionization detector (FID), and a morphological analysis of soot samples has been made using a scanning electron microscope (SEM). Physical probes have been used for temperature measurements and extraction of soot particles. Chemical analysis of the composition of the polycyclic aromatic hydrocarbons (PAHs) extracted from soot samples collected at the face of the burner and on a filter located downstream in the exhaust system suggests that multiple, convergent pathways, rather than one chemical mechanism, lead to the formation of high molecular weight PAHs and soot. Net soot production was found to be the result of the competition of soot particle formation and burnout. The fuel type and the fuel stream heat content appear the main parameters that determine the flame's propensity to soot. The addition of nitrogen to a fuel stream increases the difference in the net soot production among the fuel investigated. Dilution by nitrogen decreases more effectively the oxidation rate of soot particles in flames that use fuels of lower heat content.

  11. Biological flocculation treatment on distillery wastewater and recirculation of wastewater.

    Science.gov (United States)

    Zhang, Wen; Xiong, Rongchun; Wei, Gang

    2009-12-30

    In the present study, a wastewater treatment system for the ethanol fermentation industry was developed by recycling distillery wastewater. The waste was able to be recycled for the next fermentation after being treated with bio-flocculation process. The bio-flocculation process contains three steps: screening, treatment with polyaspartic acid and filtration. When the filtrate from this process was recycled, the average ethanol production yield was very close to that in the conventional process using tap water. In contrast, the recycle of wastewater without flocculation and with chemical flocculation showed negative effects on ethanol yield as recycling was repeated. This new process was confirmed to have stable operation over ten recycles. Hazardous materials influencing distillery wastewater recycles on fermentation were also considered. It was found that the content of suspended solids (SS), volatile acid and Fe ions inhibited fermentation and resulted in a decreased ethanol yield. Bio-flocculation was shown to be an effective way to diminish the content of inhibitory compounds drastically when the waste was recirculated.

  12. Design of a High-Reynolds Number Recirculating Water Tunnel

    Science.gov (United States)

    Daniel, Libin; Elbing, Brian

    2014-11-01

    An experimental fluid mechanics laboratory focused on turbulent boundary layers, drag reduction techniques, multiphase flows and fluid-structure interactions has recently been established at Oklahoma State University. This laboratory has three primary components; (1) a recirculating water tunnel, (2) a multiphase pipe flow loop, and (3) a multi-scale flow visualization system. The design of the water tunnel is the focus of this talk. The criteria used for the water tunnel design was that it had to produce a momentum-thickness based Reynolds number in excess of 104, negligible flow acceleration due to boundary layer growth, maximize optical access for use of the flow visualization system, and minimize inlet flow non-uniformity. This Reynolds number was targeted to bridge the gap between typical university/commercial water tunnels (103) and the world's largest water tunnel facilities (105) . These objectives were achieved with a 152 mm (6-inch) square test section that is 1 m long and has a maximum flow speed of 10 m/s. The flow non-uniformity was mitigated with the use of a tandem honeycomb configuration, a settling chamber and an 8.5:1 contraction. The design process that produced this final design will be presented along with its current status.

  13. Greenhouse gas emissions from landfill leachate treatment plants: A comparison of young and aged landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun, E-mail: xjwang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jia, Mingsheng, E-mail: msjia@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Xiaohai, E-mail: cxiaoh_xm@126.com [Xiamen City Environmental Sanitation Management Department, Xiamen 361000 (China); Xu, Ying, E-mail: yxu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Lin, Xiangyu, E-mail: xylin@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Kao, Chih Ming, E-mail: jkao@mail.nsysu.edu.tw [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Chen, Shaohua, E-mail: shchen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2014-07-15

    Highlights: • Young and aged leachate works accounted for 89.1% and 10.9% of 33.35 Gg CO{sub 2} yr{sup −1}. • Fresh leachate owned extremely low ORP and high organic matter content. • Strong CH{sub 4} emissions occurred in the fresh leachate ponds, but small in the aged. • N{sub 2}O emissions became dominant in the treatment units of both systems. • 8.45–11.9% of nitrogen was removed as the form of N{sub 2}O under steady-state. - Abstract: With limited assessment, leachate treatment of a specified landfill is considered to be a significant source of greenhouse gas (GHG) emissions. In our study, the cumulative GHG emitted from the storage ponds and process configurations that manage fresh or aged landfill leachate were investigated. Our results showed that strong CH{sub 4} emissions were observed from the fresh leachate storage pond, with the fluxes values (2219–26,489 mg C m{sup −2} h{sup −1}) extremely higher than those of N{sub 2}O (0.028–0.41 mg N m{sup −2} h{sup −1}). In contrast, the emission values for both CH{sub 4} and N{sub 2}O were low for the aged leachate tank. N{sub 2}O emissions became dominant once the leachate entered the treatment plants of both systems, accounting for 8–12% of the removal of N-species gases. Per capita, the N{sub 2}O emission based on both leachate treatment systems was estimated to be 7.99 g N{sub 2}O–N capita{sup −1} yr{sup −1}. An increase of 80% in N{sub 2}O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO{sub 2}, with a small portion as CH{sub 4} (<0.3%) during both treatment processes. The cumulative GHG emissions for fresh leachate storage ponds, fresh leachate treatment system and aged leachate treatment system were 19.10, 10.62 and 3.63 Gg CO{sub 2} eq yr{sup −1}, respectively, for a total that could be transformed to 9.09 kg CO{sub 2} eq capita{sup −1} yr{sup −1}.

  14. Recirculation of Chilean copper smelting dust with high impurities contents to the smelting process

    Energy Technology Data Exchange (ETDEWEB)

    Sano, H.; Fujisawa, T. [Nagoya Univ., Nagoya (Japan). EcoTopia Science Inst.; Montenegro, V. [Nagoya Univ., Nagoya (Japan). Dept. of Materials Science and Engineering

    2007-07-01

    Dust generated during the copper smelting process is generally stabilized using hydrometallurgical methods as it contains high concentrations of arsenic. In this laboratory study, dust was recirculated during the smelting process in order to recover more copper and decrease dust emissions while recovering more copper. The behaviour of impurities and their influence on matte quality was also investigated. Industrial matte, flue dust, slag, and copper concentrates from a Chilean smelter were used as test materials. Dust recirculation tests were conducted in a simulated electric furnace. Off-gases were collected in a reaction tube, and the condensed volatile matter, slag, and matte phases were analyzed for their elemental content by inductively coupled plasma atomic emission spectrometry. The distribution of arsenic (As); antimony (Sb), bismuth (Bi), lead (Pb), and zinc (Zn) were investigated by varying the amounts of dust recirculating to the smelting stage with 21 per cent of the oxygen. Results showed that distributions of all analyzed elements increased with recirculation. It was concluded that copper can be recovered using the dust recirculation technique. However, impurities may limit the efficacy of the dust recirculation process. 6 refs., 3 tabs., 4 figs.

  15. Treatment of Landfill Leachate by Fenton Oxidation Process

    Institute of Scientific and Technical Information of China (English)

    ZHANGHui; HUANGChin-Pao

    2002-01-01

    Central composite design (CCD), the most popular design of response surface methodology (RSM), was employed to investigate the effect of total organic carbon (TOC) ratio of high molecular weight organic matter (HMW) to low molecular weight organic matter (LMW), the LMW strength and molar ratio of hydrogen peroxide to ferrous ion on landfill leachate treatment by Fention process. Based on the experimental data, a response surface quadratic model in terms of actual factors was obtained through analysis of variance (ANOVA). The model showed that TOC removal increased with the increase of HMW to LMW ratio and the decrease of LMW strength. There existed an optimal hydrogen peroxide to ferrous ion molar ratio for TOC removal.

  16. Landfill leachate treatment by solar-driven AOPs

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Elisangela M.R. [Universidade Federal do Ceara, Campus do Pici, Centro de Tecnologia, Departamento de Engenharia Hidraulica e Ambiental, Laboratorio de Saneamento (LABOSAN), Avenida da Universidade, 2853 - Benfica, 60020-181 Fortaleza (Brazil); Vilar, Vitor J.P.; Boaventura, Rui A.R. [LSRE - Laboratory of Separation and Reaction Engineering, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Fonseca, Amelia; Saraiva, Isabel [Efacec Ambiente, SA, Rua Eng. Frederico Ulrich - Guardeiras, Apartado 3003, 4471-907 Moreira da Maia (Portugal)

    2011-01-15

    Sanitary landfill leachate resulting from the rainwater percolation through the landfill layers and waste material decomposition is a complex mixture of high-strength organic and inorganic compounds which constitutes serious environmental problems. In this study, different heterogeneous (TiO{sub 2}/UV, TiO{sub 2}/H{sub 2}O{sub 2}/UV) and homogenous (H{sub 2}O{sub 2}/UV, Fe{sup 2+}/H{sub 2}O{sub 2}/UV) photocatalytic processes were investigated as an alternative for the treatment of a mature landfill leachate. The addition of H{sub 2}O{sub 2} to TiO{sub 2}/UV system increased the reduction of the aromatic compounds from 15% to 61%, although mineralization was almost the same. The DOC and aromatic content abatement is similar for the H{sub 2}O{sub 2}/UV and TiO{sub 2}/H{sub 2}O{sub 2}/UV processes, although the H{sub 2}O{sub 2} consumption is three times higher in the H{sub 2}O{sub 2}/UV system. The low efficiency of TiO{sub 2}/H{sub 2}O{sub 2}/UV system is presumably due to the alkaline leachate solution, for which the H{sub 2}O{sub 2} becomes highly unstable and self-decomposition of H{sub 2}O{sub 2} occurs. The efficiency of the TiO{sub 2}/H{sub 2}O{sub 2}/UV system increased 10 times after a preliminary pH correction to 4. The photo-Fenton process is much more efficient than heterogeneous (TiO{sub 2}, TiO{sub 2}/H{sub 2}O{sub 2}/UV) or homogeneous (H{sub 2}O{sub 2}/UV) photocatalysis, showing an initial reaction rate more than 20 times higher, and leading to almost complete mineralization of the wastewater. However, when compared with TiO{sub 2}/H{sub 2}O{sub 2}/UV with acidification, the photo-Fenton reaction is only two times faster. The optimal initial iron dose for the photo-Fenton treatment of the leachate is 60 mg Fe{sup 2+} L{sup -1}, which is in agreement with path length of 5 cm in the photoreactor. The kinetic behaviour of the process (60 mg Fe{sup 2+} L{sup -1}) comprises a slow initial reaction, followed by a first-order kinetics (k = 0.020 LkJ{sub UV

  17. [Influence of biological activated carbon dosage on landfill leachate treatment].

    Science.gov (United States)

    Cui, Yan-Rui; Guo, Yan; Wu, Qing

    2014-08-01

    Effects of biological activated carbon (BAC) dosage on COD removal in landfill leachate treatment were compared. The COD removal efficiency of reactors with 0, 100 and 300 g activated carbon dosage per litre activated sludge was 12.9%, 19.6% and 27.7%, respectively. The results indicated that BAC improved the refractory organic matter removal efficiency and there was a positive correlation between COD removal efficiency and BAC dosage. The output of carbon dioxide after 8h of aeration in reactors was 109, 193 and 306 mg corresponding to the activated carbon dosages mentioned above, which indicated the amount of biodegradation and BAC dosage also had a positive correlation. The combination of adsorption and bioregeneration of BAC resulted in the positive correlation betweem organic matter removal efficiency and BAC dosage, and bioregeneration was the root cause for the microbial decomposition of refractory organics.

  18. Use of vetiver grass constructed wetland for treatment of leachate.

    Science.gov (United States)

    Bwire, K M; Njau, K N; Minja, R J A

    2011-01-01

    Performance of Constructed Wetland planted with vetiver grasses for the treatment of leachate was investigated in controlled experiments involving horizontal subsurface flow constructed wetland (HSSFCW). The HSSFCW experimental unit had two cells, one planted with vetiver grasses and another bare. Both units were packed with limestone gravel as substrate and were operated with equal hydraulic loading and hydraulic retention time. Collected samples of influents and effluents were analysed for COD, Cr, Pb, Fe and pH. The results showed that vetiver grasses tolerated leachate with high loading of COD up to 14,000 mg L(-1). The planted cell outperformed the unplanted cell in terms of COD, Cr, Pb and Fe removal. The systems showed optimum points for COD and Pb removal as a function of feed concentrations. The optimum COD removal values of 210 mgm(-2) day(-1) at feed COD concentration of 11,200 mg COD L(-1) and 89 mgm(-2) day(-1) at feed concentration of 7,200 mg COD L(-1) were obtained for planted and unplanted cells respectively. Similarly Pb removal values of 0.0132 mgm(-2) day(-1) at 1.0 mg Pb L(-1) and 0.0052 mgm(-2) day(-1) at 1.04 mgPb L(-1) were obtained for planted and unplanted units respectively. Removal of Fe as a function of feed Fe concentration showed a parabolic behaviour but Cr removal showed linear behaviour with feed Cr concentrations in both units. The system showed very good removal efficiencies with Cr and Fe but poor efficiencies were recorded for Pb.

  19. Nitrogen removal via nitrite from municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    WU Lina; PENG Chengyao; ZHANG Shujun; PENG Yongzhen

    2009-01-01

    A system consisting of a two-stage up-flow anaerobic sludge blanket (UASB),an anoxic/aerobic (A/O) reactor and a sequencing batch reactor (SBR),was used to treat landfill leachate.During operation,denitrification and methanogenesis took place simultaneously in the first stage UASB (UASB1),and the effluent chemical oxygen demand (COD) was further removed in the second stage UASB (UASB2).Then the denitrification of nitrite and nitrate in the returned sludge by using the residual COD was accomplished in the A/O reactor,and ammonia was removed via nitrite in it.Last but not least,the residual ammonia was removed in SBR as well as nitrite and nitrate which were produced by nitrification.A system consisting of a two-stage UASB and an A/O reactor was used to achieve the stable short-cut nitrification in the first stage (60 d).The effluent of stage one was treated by SBR in the second stage (60 d).The results over 120 d were as follows: when the total nitrogen (TN) concentration of influent leachate was about 2500 mg/L and the ammonia nitrogen concentration was about 2000 mg/L,the short-cut nitrification with 85%-90% nitrite accumulation was achieved stably in the A/O reactor.The TN and ammonia nitrogen removal efficiencies of the system were 98% and 97%,respectively.The residual ammonia,nitrite and nitrate which were produced by nitrification in the A/O reactor could be washed out almost completely in SBR.The TN and ammonia nitrogen concentrations of final effluent were about 39 mg/L and 12 mg/L,respectively.

  20. Generation of leachate and the flow regime in landfills

    Energy Technology Data Exchange (ETDEWEB)

    Bendz, D.

    1998-06-01

    In this thesis the generation of leachate and the presence and movement of water in landfilled municipal solid waste (MSW) is investigated. The precipitation-leachate discharge relationship for landfills was found to be dominated by evaporation, accumulation in the soil cover, accumulation in the solid waste and fast gravitational flow in a network of channels. The flow regime is governed by the heterogeneity of the internal geometry of the landfill, which is characterized by a discrete structure, significant horizontal stratification, structural voids, impermeable surfaces, and low capillarity. Also the boundary conditions, that is the water input pattern, has shown to be important for the flow process. Based on this, landfilled waste can be conceptualized as a dual domain medium, consisting of a channel domain and a matrix domain. The matrix flow is slow and diffusive, whereas the channel flow is assumed to be driven solely by gravity and to take place as a thin viscous film on solid surfaces. A kinematic wave model for unsaturated infiltration and internal drainage in the channel domain is presented. The model employs a two-parameter power expression as macroscopic flux law. Solutions were derived for the cases when water enters the channel domain laterally and when water enters from the upper end. The model parameters were determined and interpreted in terms of the internal geometry of the waste medium by fitting the model to one set of infiltration and drainage data derived from a large scale laboratory experiment under transient conditions. The model was validated using another set of data from a sequence of water input events and was shown to perform accurately. A solute transport model was developed by coupling a simple piston flux expression and a mobile-immobile conceptualization of the transport domains with the water flow model. Breakthrough curves derived from steady and transient tracer experiments where interpreted with the model. The transport

  1. A Study on the Adverse Effect of AOVs in AFWS Recirculation Paths on Plant Safety

    Energy Technology Data Exchange (ETDEWEB)

    Huong, Ho Thi Thanh [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Chung, Dae-Wook [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2014-10-15

    Auxiliary feedwater system (AFWS) recirculation flow paths adopted air operated valves (AOVs) which could fail close on loss of instrument air (LOIA) event. So the AOVs and recirculation paths are closed on LOIA event, which could result in Auxiliary feedwater (AFW) pump(s) damage, which contributes greatly to core damage frequency (CDF).. On February 2002, the USNRC issued an inspection finding related to potential common cause failure of AOVs in AFWS recirculation flow paths on loss of instrument air system in Point Beach nuclear power plant (Pt. Beach). The AOVs have been removed from AFWS recirculation paths in the design of Korea standard nuclear power plant (KSNP). So, there is no possibility of above mentioned failure event in KSNP. It would be beneficial to evaluate the significance of adverse effect of AOVs in AFWS recirculation paths to realize the importance of maintaining AFWS recirculation paths always open. In this study, the AFWS modeling of Ulchin unit 3 and 4 was modified to model the AOVs in AFW recirculation flow paths to evaluate the change in CDF, which is caused by the adverse effect of AOV with operation mode of 'fails close' on LOIA event. It is concluded that the existence of AOV with 'fail close' design in AFWS MDP recirculation paths results in CDF increase of 131%, which is significant adverse effect on plant safety.. In this regard, the improved Westinghouse design and KSNP design had removed the AOVs from AFWS MDP recirculation paths. However, a couple of units with old Westinghouse design, Kori 1 and 2, still have AOVs in AFWS MDP recirculation paths and throttle back operation of AFWS is in effect. Although those AOVs adopt 'fail open' design to prevent above mentioned inadvertent closure, considering the big increase in CDF, there still exists considerable risk from the possibility of 'failure to open' during this throttle back operation. Therefore, it is strongly recommended that any

  2. Fresh Kills leachate treatment and minimization study. Volume 1, Characteristics and treatment alternatives: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fillos, J.; Khanbilvardi, R.

    1993-09-01

    The New York City Department of Sanitation is developing a comprehensive landfill leachate management plan for the Fresh Kills Landfill. The leachate was first analyzed for conventional and priority pollutants. The leachate was well buffered at pH 7 to 8 with an alkalinity of 5,000 to 6,000 mg/L. The BOD was low, usually less than 100 mg/L, but the COD was as high as 1,800 mg/L. Ammonia concentrations were around 700 mg/L and the color resembled strong tea at 3,000 colorimetric units. Only few of the priority pollutants were present, and at extremely low concentrations. Based on the chemical characteristics of the leachate, the primary environmental impact would be on the oxygen balance of the receiving surface waters.

  3. Physiological responses of Vetiver plant (Vetiver zizanioides) to municipal waste leachate

    National Research Council Canada - National Science Library

    Sasan Mohsenzadeh; Nadereh Naderi; Mahdi Nazari

    2016-01-01

    Vetiver plant is tolerant to acidity and temperature variations. Has rapid growth for biomass production and has high tolerance to organic and non-organic compounds in municipal waste leachate for example heavy metals...

  4. Variability in the concentration of indicator bacteria in landfill leachate--a comparative study.

    Science.gov (United States)

    Umar, Muhammad; Aziz, Hamidi Abdul; Yusoff, Mohd Suffian

    2015-03-01

    Leachate collected from the collection ponds of four landfill sites was investigated and compared for total coliforms and E. coli concentration as representatives of fecal pollution. Concentration of total coliforms and E. coli was comparable for leachate obtained from Kulim Landfill Site (KLS) and Ampang Landfill Site (ALS) with little variations. However, the level of indicator bacteria was significantly lower for Kuala Sepetang Landfill Site (KSLS), whereas Pulau Burung Landfill Site (PBLS) had the lowest concentration for both total coliforms and E. coli. Considering the landfills are currently operational, with the exception of ALS, the presence of indicator bacteria implies their inactivation prior to discharge. High concentration of indicator bacteria in ALS is attributed to the run-off entering the leachate pond. Greater concentration of ammonia and salinity level were partly responsible for lower concentration of indicator bacteria in leachate from KSLS and PBLS, indicating that salinty and ammonia could significantly affect the survival of indicator bacteria.

  5. Present and long-term composition of MSW landfill leachate: A review

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Barlaz, M.A.; Rooker, A.P.;

    2002-01-01

    The major potential environmental impacts related to landfill leachate are pollution of groundwater and surface waters. Landfill leachate contains pollutants that can be categorized into four groups (dissolved organic matter, inorganic macrocomponents, heavy metals, and xenobiotic organic compounds......). Existing data show high leachate concentrations of all components in the early acid phase due to strong decomposition and leaching. In the long methanogenic phase a more stable leachate, with lower concentrations and a low BOD/COD-ratio, is observed. Generally, very low concentrations of heavy metals...... is discussed based on theory and model simulations. It seems that the somewhere postulated enhanced release of accumulated heavy metals would not take place within the time frames of thousands of years. This is supported by a few laboratory investigations. The existing data and model evaluations indicate...

  6. From a Literature Review to an Alternative Treatment System for Landfill Gas and Leachate

    Directory of Open Access Journals (Sweden)

    Tao Huang

    2012-12-01

    Full Text Available This paper provides an alternative treatment system for landfill gas and leachate control in order to reduce the energy consumption and disposal cost, using the recycled landfill gas as the combustion promoter for incineration of the leachate. This study starts by providing a literature review to summarize and analyze different approaches being applied to landfill leachate treatment. Subsequently, a conceptual prototype is proposed, which can be built using existing technology by means of technical possibility analysis, whilst economic benefits could be returned through preliminary comparison. With the proposed introduction of a “waste treatment park”, this alternative treatment system could provide a template for leachate and landfill gas control. This study may provide an insight for landfill operators and engineers to promote the transformation from the conceptual framework to the real achievement. Finally, the limitations of the conceptual model and analysis are discussed, laying a foundation for further work.

  7. Monitoring of landfill leachate dispersion using reflectance spectroscopy and ground-penetrating radar.

    Science.gov (United States)

    Splajt, T; Ferrier, G; Frostick, L E

    2003-09-15

    The utility of ground-penetrating radar and reflectance spectroscopy in the monitoring of landfill sites has been investigated. Strong correlations between red edge inflection position and chlorophyll and heavy metal concentrations have been demonstrated from grassland species affected by leachate contamination of the soil adjacent to the landfill test site. This study demonstrated that reflectance spectroscopy can identify vegetation affected by leachate-contaminated soil at a range of spatial resolutions. To identify the vegetation affected by leachate contamination, the spectroradiometer must have contiguous bands at sufficient spectral resolution over the critical wave range that measures chlorophyll absorption and the red edge (between 650 and 750 nm). The utility of ground-penetrating radar data to identify leachate escaping from breakout points in the contaminant wall has also been demonstrated. An integrated approach using these techniques, combined with field and borehole sampling and contaminant migration modeling, offers a possible cost-effective monitoring approach for landfill sites.

  8. Fly ash leachate generation and qualitative trends at Ohio test sites

    Energy Technology Data Exchange (ETDEWEB)

    Solc, J.; Foster, H.J.; Butler, R.D. [Energy & Environmental Research Center, Grand Forks, ND (United States)

    1995-12-01

    Under the sponsorship of the U.S. Department of Energy, the environmental impact and potential contamination from landfilled fly ash (coal conversion solid residues - CCSRs) have been studied at field sites in Ohio. The progressive increase of moisture content within pilot cells over depth and time facilitated intensive chemical processes and generation of highly alkaline (pH of 10 to 12) leachate. Chemistry of pore water from lysimeters and ASTM leachate from fly ash and soil cores indicate the leachate potential to migrate out of deposit and impact the pore water quality of surrounding soils. Na, SO{sub 4} and, particularly, K, Cl, pH, and EC appeared to be valuable indicator parameters for tracking potential leachate transport both within the cells and below the ash/soil interface.

  9. Closed recirculating system for shrimp-mollusk polyculture

    Science.gov (United States)

    Wu, Xiongfei; Zhao, Zhidong; Li, Deshang; Chang, Kangmei; Tong, Zhuanshang; Si, Liegang; Xu, Kaichong; Ge, Bailin

    2005-12-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducting the probiotic products timely into the shrimp ponds; adopting a “pen-closing” method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965 kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  10. Progress toward a prototype recirculating ion induction accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, A.; Barnard, J.J.; Cable, M.D. [and others

    1996-06-01

    The U.S. Inertial Fusion Energy (IFE) Program is developing the physics and technology of ion induction accelerators, with the goal of electric power production by means of heavy ion beam-driven inertial fusion (commonly called heavy ion fusion, or HIF). Such accelerators are the principal candidates for inertial fusion power production applications, because they are expected to enjoy high efficiency, inherently high pulse repetition frequency (power plants are expected to inject and burn several fusion targets per second), and high reliability. In addition (and in contrast with laser beams, which are focused with optical lenses) heavy-ion beams will be focused onto the target by magnetic fields, which cannot be damaged by target explosions. Laser beams are used in present-day and planned near-term facilities (such as LLNUs Nova and the National Ignition Facility, which is being designed) because they can focus beams onto very small, intensely illuminated spots for scaled experiments and because the laser technology is already available. An induction accelerator works by passing the beam through a series of accelerating modules, each of which applies an electromotive force to the beam as it goes by; effectively, the beam acts as the secondary winding of a series of efficient one-turn transformers. The authors present plans for and progress toward the development of a small (4.5-m-diam) prototype recirculator, which will accelerate singly charged potassium ions through 15 laps, increasing the ion energy from 80 to 320 keV and the beam current from 2 to 8 mA. Beam confinement and bending are effected with permanent-magnet quadrupoles and electric dipoles, respectively. The design is based on scaling laws and on extensive particle and fluid simulations of the behavior of the space charge-dominated beam.

  11. Closed recirculating system for shrimp-mollusk polyculture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducing the probiotic products timely into the shrimp ponds; adopting a "pen-closing" method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

  12. IC ENGINE SUPERCHARGING AND EXHAUST GAS RECIRCULATION USING JET COMPRESSOR

    Directory of Open Access Journals (Sweden)

    Adhimoulame Kalaisselvane

    2010-01-01

    Full Text Available Supercharging is a process which is used to improve the performance of an engine by increasing the specific power output whereas exhaust gas recirculation reduces the NOx produced by engine because of supercharging. In a conventional engine, supercharger functions as a compressor for the forced induction of the charge taking mechanical power from the engine crankshaft. In this study, supercharging is achieved using a jet compressor. In the jet compressor, the exhaust gas is used as the motive stream and the atmospheric air as the propelled stream. When high pressure motive stream from the engine exhaust is expanded in the nozzle, a low pressure is created at the nozzle exit. Due to this low pressure, atmospheric air is sucked into the expansion chamber of the compressor, where it is mixed and pressurized with the motive stream. The pressure of the mixed stream is further increased in the diverging section of the jet compressor. A percentage volume of the pressurized air mixture is then inducted back into the engine as supercharged air and the balance is let out as exhaust. This process not only saves the mechanical power required for supercharging but also dilutes the constituents of the engine exhaust gas thereby reducing the emission and the noise level generated from the engine exhaust. The geometrical design parameters of the jet compressor were obtained by solving the governing equations using the method of constant rate of momentum change. Using the theoretical design parameters of the jet compressor, a computational fluid dinamics analysis using FLUENT software was made to evaluate the performance of the jet compressor for the application of supercharging an IC engine. This evaluation turned out to be an efficient diagnostic tool for determining performance optimization and design of the jet compressor. A jet compressor was also fabricated for the application of supercharging and its performance was studied.

  13. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture

    Directory of Open Access Journals (Sweden)

    S. Sumoharjo

    2013-06-01

    Full Text Available Integrated multi-trophic aquaculture pays more attention as a bio-integrated food production system that serves as a model of sustainable aquaculture, minimizes waste discharge, increases diversity and yields multiple products. The objectives of this research were to analyze the efficiency of total ammonia nitrogen biofiltration and its effect on carrying capacity of fish rearing units. Pilot-scale bioreactor was designed with eight run-raceways (two meters of each that assembled in series. Race 1-3 were used to stock silky worm (Tubifex sp as detrivorous converter, then race 4-8 were used to plant three species of leaf-vegetable as photoautotrophic converters, i.e; spinach (Ipomoea reptana, green mustard (Brassica juncea and basil (Ocimum basilicum. The three plants were placed in randomized block design based on water flow direction. Mass balance of nutrient analysis, was applied to figure out the efficiency of bio-filtration and its effect on carrying capacity of rearing units. The result of the experiment showed that 86.5 % of total ammonia nitrogen removal was achieved in 32 days of culturing period. This efficiency able to support the carrying capacity of the fish tank up to 25.95 kg/lpm with maximum density was 62.69 kg/m3 of fish biomass productionDoi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85 [How to cite this article: Sumoharjo, S.  and Maidie, A. (2013. Evaluation on Biofilter in Recirculating Integrated Multi-Trophic Aquaculture.  International Journal of  Science and Engineering, 4(2,80-85. Doi: http://dx.doi.org/10.12777/ijse.4.2.2013.80-85

  14. FITOREMEDIASI KADMIUM (CD PADA LEACHATE MENGGUNAKAN KANGKUNG AIR (Ipomoea aquatica Forsk. (STUDI KASUS TPA JATIBARANG

    Directory of Open Access Journals (Sweden)

    K N Zamhar

    2016-03-01

    Full Text Available Leachate TPA Jatibarang yang tercemar kadmium (Cd kemungkinan dapat dibersihkan secara fitoremediasi menggunakan kangkung air (Ipomoea aquatica Forsk.. Penelitian ini bertujuan untuk mengetahui kemampuan kangkung air sebagai fitoremediator dalam menyerap Cd dalam leachate TPA Jatibarang. Sebelum penelitian, dilakukan uji pendahuluan kandungan Cd dalam leachate maupun dalam kangkung air. Kangkung diaklimatisasi dalam air bersih selama 3 hari, selanjutnya ditimbang seberat 300 gram kemudian diletakkan ke dalam ember berisi 10 L leachate. Sampel leachate dan organ tanaman diambil setiap 2 hari sekali (2 hari, 4 hari, 6 hari, dan 8 hari. Faktor intensitas cahaya diambil setiap hari pada pukul 08.00-09.00 WIB menggunakan lux meter, sedangkan nilai pH dan suhu leachate diukur menggunakan kertas indikator pH dan termometer sebelum dan sesudah perlakuan. Perameter yang diamati adalah akumulasi Cd dalam akar, batang, dan daun kangkung air pada masing-masing lama waktu pananaman. Akumulasi Cd diukur dengan AAS (Atomic Absorption Spectrophotometry. Data penyerapan Cd dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa lama waktu kangkung air ditanam dalam leachate berpengaruh terhadap akumulasi Cd pada tanaman. Penyerapan Cd oleh kangkung air mencapai jenuh pada hari ke-8 dengan total penyerapan 0,052 ppm. Akumulasi Cd paling besar pada akar kangkung yaitu 0,023 ppm.Cadmium (Cd that contained in TPA Jatibarang’s leachate can be cleaned by phytoremediation using water spinach (Ipomoea aquatica Forsk.. This research aimed to determine the ability of the water spinach as a fitoremediator in adsorb cadmium (Cd that contained in TPA Jatibarang’s leachate. The research was conducted by using a randomized completely design (RCD factorial, with longer treatment planted time in leachate water spinach was 0 day, 2 days, 4 days, 6 days, and 8 days respectively. The observed parameters of Cd accumulation in roots, stems, and leaves of water spinach in

  15. Phytoremediation of Polychlorobiphenyls PCBs in Landfill E-Waste Leachate with Water Hyacinth E.Crassipes

    OpenAIRE

    E.A Omondi; P.K Ndiba and P.G Njuru

    2015-01-01

    Abstract The presence of e-waste in a landfill can release persistent organic pollutants POPs including polychlorinated biphenyls PCBs into the environment. PCBs are a family of more than 200 chemical compounds congeners each of which consists of two benzene rings and one to ten chlorine atoms. This study investigated use of water hyacinth Eichhornia crassipes for phytoremediation of landfill leachate waste containing PCB. Landfill leachate was simulated in the laboratory by spiking water sam...

  16. Application of Deuterium and Oxygen-18 to Trace Leachate Movement in Bantar Gebang Sanitary Landfill

    Directory of Open Access Journals (Sweden)

    E.R. Pujiindiyati

    2011-08-01

    Full Text Available Bantar Gebang landfill was constructed in 1986 with total area of 108 ha and approximately 6000 ton/day solid waste is disposed to this landfill. Mostly, the people living surrounding landfill get afraid of impact of the hazardous chemicals produced by waste disposal to their health. The purpose of this investigation was to study the migration of leachate to Cibitung River water and shallow groundwaters near to the river. It is possible to be done because chemical contents and isotopic characteristics of municipal landfill leachate are unique, relative to aqueous media in the most natural environments. Laser absorption method developed by the LGR (Los Gatos Research was used to measure absolute abundances of 2HHO, HH18O and HHO in a number of water samples. In-situ measurements were also conducted as an additional parameter besides their isotopes. The δ2H of the H2O in landfill leachate was significantly enriched, with values of - 22.6 ‰ to + 4.3 ‰. This deuterium enrichment was undoubtedly due to the extensive production of microbial methane within the limited reservoir of the landfill. However, the enriched deuterium value in leachate was not detected in the river which still had depleted values. It was probably caused by the amount of natural water in the river was comparatively large, with respect to limited leachate discarded to the river.The electrical conductivity of the leachate was higher (3200 to 7600 S and the decreasing values were still monitored in the river to approximately 12 km after streaming the landfills. The effect of the high electrical conductivity and enriched deuterium of leachate was not clearly indicated in the groundwater samples which still represented the local precipitation recharge, except a monitoring well located in Bantar Gebang landfill area which has an indication of leachate contamination.

  17. Comparison of Diffrent Coagulants Efficiency for Treatment of Hamedan Landfills Leachate Site

    Directory of Open Access Journals (Sweden)

    J. Hasanvand

    2010-04-01

    Full Text Available "n "n "nBackgrounds and Objectives:In Iran , indicated that the municipal landfill leachate has been one of the major problem for environment. In the operations, leachate treatment is a very difficult and expensive process. Although, young leachate can be treated easily by biological treatment, COD removal efficiency are usually low due to high ammonium ion content and the presence of toxic compounds such as metal ions. Treatment of leachate is necessary.The aim of this study is reduction of Chemical Oxygen Demond (COD and Total Suspended Solids (TSS from hamedan city sanitary landfill leachate by three coagulants: alum, PAC and ferrous sulfate."nMaterials and Methods: This experimental study was conducted to investigate the effect of treatment of landfill leachate by a coagulation-flocculation process. The effects of different amounts of coagulant and different pH values on the coagulation processes were compared."nResults:Result shown the high efficiency for reduction of CODby PAC in pH=12 and concentration of 2500(mg/l (62.66%, and by alum in pH=12 and concentration of 1000 (mg/l (60% , by ferrous sulfate in pH=2 and concentration of 1000 (mg/l (70.62%. Also result shown the high efficiency for TSS removal by PAC in pH=12 and 2500(mg/l concentration of PAC was 58.37%, with alum in pH=2 and 1500 (mg/l concentration of alum was39.14% , by ferrous sulfate in pH=7 and 2500(mg/l concentration of ferrous sulfate was 35.58%."nConclusion:The best coagulant for COD removal is ferrous sulfate.The physico-chemical process may be used as a useful pretreatment step, especially for fresh leachates, prior to post-treatment (polishing step for partially stabilized leachates.

  18. THE "CHEMICAL OXYGEN DEMAND / TOTAL VOLATILE ACIDS" RATIO AS AN ANAEROBIC TREATABILITY INDICATOR FOR LANDFILL LEACHATES

    OpenAIRE

    Contrera,R. C.; K. C. da Cruz Silva; G. H. Ribeiro Silva; D. M. Morita; Zaiat,M.; V. Schalch

    2015-01-01

    Abstract In some operational circumstances a fast evaluation of landfill leachate anaerobic treatability is necessary, and neither Biochemical Methane Potential nor BOD/COD ratio are fast enough. Looking for a fast indicator, this work evaluated the anaerobic treatability of landfill leachate from São Carlos-SP (Brazil) in a pilot scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR). The experiment was conducted at ambient temperature in the landfill area. After the acclimation, at a ...

  19. Treatment of Navy Landfill Leachate Contaminated with Low Levels of Priority Pollutants

    Science.gov (United States)

    1991-10-01

    EFD). Because the landfills were unlined, there is the strong possibility that the leachate has migrated into the groundwater. The data therefore are...converted into ammonium ions, NH4 , which are readily soluble and may give rise to significant quantities of ammonia in the leachate. The landfill quickly...aeration basin X - mixed liquor suspended solids (MLSS) 32 Table IV-4 lists the advantages and disadvantages of the two reactor systems. The restrictions

  20. Separation of heavy metals from landfill leachate by reactive liquid-liquid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Mickler, W. [Potsdam Univ. (Germany). Inst. fuer Anorganische Chemie und Didaktik der Chemie

    2001-05-01

    The objective of this work was to investigate the decontamination of a model landfill leachate by simultaneous separation of heavy metals from alkaline earth metals and iron in order to obtain a leachate that can be led back to the landfill. Reactive extraction as a separation process offers the possibility of selectively separating cations, that is, of separating toxic components from less problematic ones, and also includes the possibility of electrolysis and further processes to obtain the desired metals. (orig.)

  1. Geochemistry of leachates from the El Fraile sulfide tailings piles in Taxco, Guerrero, southern Mexico.

    Science.gov (United States)

    Talavera Mendoza, Oscar; Armienta Hernández, Ma Aurora; Abundis, José García; Mundo, Nestor Flores

    2006-06-01

    Leachates from the El Fraile tailings impoundment (Taxco, Mexico) were monitored every 2 months from October 2001 to August 2002 to assess the geochemical characteristics. These leachates are of interest because they are sometimes used as alternative sources of domestic water. Alternatively, they drain into the Cacalotenango creek and may represent a major source of metal contamination of surface water and sediments. Most El Fraile leachates show characteristics of Ca-SO(4), (Ca+Mg)-SO(4), Mg-SO(4 )and Ca-(SO(4)+HCO(3)) water types and are near-neutral (pH=6.3-7.7). Some acid leachates are generated by the interaction of meteoric water with tailings during rainfall events (pH=2.4-2.5). These contain variable levels of SO(4) (2-) (280-29,500 mg l(-1)) and As (<0.01-12.0 mg l(-1)) as well as Fe (0.025-2,352 mg l(-1)), Mn (0.1-732 mg l(-1)), Zn (<0.025-1465 mg l(-1)) and Pb (<0.01-0.351 mg l(-1)). Most samples show the highest metal enrichment during the dry seasons. Leachates used as domestic water typically exceed the Mexican Drinking Water Guidelines for sulfate, hardness, Fe, Mn, Pb and As, while acidic leachates exceed the Mexican Guidelines for Industrial Discharge Waters for pH, Cu, Cd and As. Speciation shows that in near-neutral solutions, metals exist mainly as free ions, sulfates and bicarbonates, while in acidic leachates they are present as sulfates and free ions. Arsenic appears as As((V)) in all samples. Thermodynamic and mineralogical evidence indicates that precipitation of Fe oxides and oxyhydroxides, clay minerals and jarosite as well as sorption by these minerals are the main processes controlling leachate chemistry. These processes occur mainly after neutralization by interaction with bedrock and equilibration with atmospheric oxygen.

  2. Estimation of the environmental risk posed by landfills using chemical, microbiological and ecotoxicological testing of leachates.

    Science.gov (United States)

    Matejczyk, Marek; Płaza, Grażyna A; Nałęcz-Jawecki, Grzegorz; Ulfig, Krzysztof; Markowska-Szczupak, Agata

    2011-02-01

    The leachates from 22 municipal solid waste (MSW) landfill sites in Southern Poland were characterized by evaluation of chemical, microbiological and ecotoxicological parameters. Chemical analyses were mainly focused on the identification of the priority hazardous substances according to Directive on Priority Substances, 2008/105/EC (a daughter directive of the WFD) in leachates. As showed, only five substances (Cd, Hg, hexachlorobutadiene, pentachlorobenzene and PAHs) were detected in the leachates. The compounds tested were absent or present at very low concentrations. Among them, only PAHs were found in all samples in the range from 0.057 to 77.2 μg L⁻¹. The leachates were contaminated with bacteria, including aerobic, psychrophilic and mesophilic bacteria, coliform and fecal coliforms, and spore-forming-bacteria, including Clostridium perfringens, and with filamentous fungi. From the analysis of specific microorganism groups (indicators of environmental pollution by pathogenic or opportunistic pathogenic organisms) it can be concluded that the landfill leachates showed sanitary and epidemiological hazard. In the ecotoxicological study, a battery of tests comprised of 5 bioassays, i.e. Microtox(®), Spirotox, Rotoxkit F™, Thamnotoxkit F™ and Daphtoxkit F™ magna was applied. The leachate samples were classified as toxic in 13.6%, highly toxic in 54.6% and very highly toxic in 31.8%. The Spirotox test was the most sensitive bioassay used. The percentage of class weight score was very high - above 60%; these samples could definitely be considered seriously hazardous and acutely toxic to the fauna and microflora. No correlations were found between the toxicity values and chemical parameters. The toxicity of leachate samples cannot be explained by low levels of the priority pollutants. It seems that other kinds of xenobiotics present in the samples at subacute levels gave the high aggregate toxic effect. The chemical, ecotoxicological and microbiological

  3. Bacterial community composition and abundance in leachate of semi-aerobic and anaerobic landfills

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Bo Yue; Qi Wang; Zechun Huang; Qifei Huang; Zengqiang Zhang

    2011-01-01

    The abundance and phylogenetic composition of bacterial community in leachate of semi-aerobic and anaerobic landfill were compared through real-time polymerase chain reaction and denaturing gradient gel electrophoresis.In semi-aerobic landfill scenario,the bacterial 16S rRNA copy numbers in leachate had no significant reduction from initial stage to stable period.In the scenario of anaerobic landfill,the largest bacterial 16S rRNA gene copy number was found in leachate at initial stage,but it reduced significantly at stable period.Moreover,methane-oxidizing bacteria population in stable period was lower than that in initial period in both two landfill processes.However,semi-aerobic landfill leachate had more methanotrophic bacteria populations than that in the anaerobic one.Furthermore,according to the sequences and phylogenetic analysis,obvious difference could be detected in bacterial community composition in different scenarios.Proteobacteria and bacteroidetes took up a dominantly higher proportion in semi-aerobic landfill leachate.To summarize up,different landfill methods and its landfill ages had crucial impacts on bacterial abundance and composition in leachate of semi-aerobic and anaerobic landfills.

  4. A simulation analysis of the migration and transformation of pollutants contained in landfill leachate

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-qi; TIAN Kai-ming; QI Yong-qiang; CHEN Jia-jun; WANG Ya-nan

    2003-01-01

    A dynamic composite model for a soil-water system that can be used to simulate the movement of leachate from a landfill. The composite model includes nine sub-models that trace water movement and the migration and transformation of five pollutants(organic N, NH4- ,NO3- , NO2- , and Cl- ) in saturated and unsaturated soil. The model to simulate the movement of leachate from a landfill in Laogang Town,Shanghai City was used. In this application, the values for the model parameters were obtained by performing a laboratory simulation experiment of water movement and pollutant migration and transformation in soil colunms. Soil and leachate obtained from the landfill site and its vicinity were used in the laboratory experiments. The model was then used to simulate leachate movement and pollutant activity during the ten-year period when the landfill was in operation and in the twenty-year period following its closure. The simulation results revealed that the leachate migrated into the groundwater at the rate of 90-100 meters per year. This model can be applied in the design of future landfills in China for the purpose of assessing and forecasting leachate plumes.

  5. Evolution of clog formation with time in columns permeated with synthetic landfill leachate

    Science.gov (United States)

    VanGulck, Jamie F.; Rowe, R. Kerry

    2004-11-01

    Laboratory column tests conducted to gain insight regarding the biological and chemical clogging mechanisms in a porous medium are presented. To seed the porous medium with landfill bacteria, a mixture of Keele Valley Landfill and synthetic leachate permeated through the column under anaerobic conditions for the first 9 days of operation. After this, 100% synthetic leachate was used. The synthetic leachate approximated Keele Valley Landfill leachate in chemical composition but contained negligible suspended solids and bacteria compared with real leachate. The removal of volatile fatty acids (VFAs), primarily acetate, in leachate as it passed through the medium was highly correlated with the precipitation of calcium carbonate (CaCO 3(s)) from solution. The columns experienced a decrease in drainable porosity from an initial value of about 0.38 to less than 0.1 after steady state chemical oxygen demand (COD) removal, resulting in a five-order magnitude decrease in hydraulic conductivity. The decrease in drainable porosity prior to steady state COD removal was primarily due to the growth of a biofilm on the medium surface. After steady state COD removal, calcium precipitation was at least equally responsible for the decrease in drainable porosity as biofilm growth. Clog composition analyses showed that CaCO 3(s) was the dominant clog constituent and that 99% of the carbonate in the clog material was bound to calcium.

  6. Acute toxicity tests on raw leachate from a Malaysian dumping site.

    Science.gov (United States)

    Sujá, Fatihah; Yusof, Arij; Osman, Md Anuar

    2010-01-01

    Leachate samples collected from the Ampar Tenang open dumping site at Dengkil, Malaysia, were analyzed for acute toxicity. Two in vivo toxicity tests, Acute Oral Toxicity (AOT) and Primary Skin Irritation (PSI), were performed using Sprague Dawley rats and New Zealand Albino rabbits, respectively. The leachate samples were also analyzed chemically for nitrate and phosphate, ammonia-nitrogen, Kjeldahl-nitrogen and Chemical Oxygen Demand (COD). Results from both the AOT and PSI tests showed that the leachate did not contribute to acute toxicity. The AOT test yielded a negative result: no effect was observed in at least half of the rat population. The PSI test on rabbits produced effects only at a leachate concentration of 100%. However, the skin irritation was minor, and the test returned a negative result. The four chemical tests showed high levels of nutrient pollution in the leachate. The nitrate and phosphate concentrations were 2.1 mg/L and 23.6 mg/L, respectively. Further, the ammonia-nitrogen concentration was 1,000 mg NH(3)-N/L the Kjeldahl-nitrogen level was 446 mg NH(3)-N/L, and the Chemical Oxygen Demand was 1,300 mg/L. The in vivo toxicity and chemical analyses showed that the leachate is polluted but not acutely toxic to organisms.

  7. Determination of leachate toxicity through acute toxicity using Daphnia pulex and Anaerobic Toxicity Assays

    Directory of Open Access Journals (Sweden)

    Patricia Torres Lozada

    2017-01-01

    Full Text Available The municipal solid waste (MSW of large cities, in particular in developing countries, is mainly disposed of in landfills (LFs, whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic digestion tests. The acute toxicity assays with Daphnia pulex presented a toxic unit (TU value of 49.5%, which indicates that these leachates should not be directly discharged into water sources or percolate into the soil because they would affect the ecosystems served by these waters. According to statistical analyses, the leachate toxicity is mainly associated with the inorganic fraction, with chlorides, calcium hardness and calcium having the greatest influence on the toxicity. The anaerobic toxicity assays showed that in the exposure stage, the methanogenic activity exceeded that of the control, which suggests that the anaerobic bacteria easily adapted to the leachate. Therefore, this treatment could be an alternative to mitigate the toxicity of the studied leachates. The inhibition presented in the recovery stage, represented by a reduction of the methanogenic activity, could arise because the amount of supplied substrate was not enough to fulfill the carbon and nutrient requirements of the bacterial population present.

  8. The potential for constructed wetlands to treat alkaline bauxite-residue leachate: Phragmites australis growth.

    Science.gov (United States)

    Higgins, D; Curtin, T; Pawlett, M; Courtney, R

    2016-12-01

    High alkalinity (pH > 12) of bauxite-residue leachates presents challenges for the long-term storage and managements of the residue. Recent evidence has highlighted the potential for constructed wetlands to effectively buffer the alkalinity, but there is limited evidence on the potential for wetland plants to establish and grow in soils inundated with residue leachate. A pot-based trial was conducted to investigate the potential for Phragmites australis to establish and grow in substrate treated with residue leachate over a pH range of 8.6-11.1. The trial ran for 3 months, after which plant growth and biomass were determined. Concentrations of soluble and exchangeable trace elements in the soil substrate and also in the aboveground and belowground biomass were determined. Residue leachate pH did not affect plant biomass or microbial biomass. With the exception of Na, there was no effect on exchangeable trace elements in the substrate; however, increases in soluble metals (As, Cd and Na) were observed with increasing leachate concentration. Furthermore, increases in Al, As and V were observed in belowground biomass and for Cd and Cr in aboveground biomass. Concentrations within the vegetation biomass were less than critical phytotoxic levels. Results demonstrate the ability for P. australis to grow in bauxite-residue leachate-inundated growth media without adverse effects.

  9. Membrane bioreactor technology: A novel approach to the treatment of compost leachate

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kayleigh; Ghoshdastidar, Avik J.; Hanmore, Jillian [Department of Chemistry, Acadia University, Wolfville, NS, Canada B4P 2R6 (Canada); Frazee, James [E and Q Consulting and Associates Limited, Wolfville, NS, Canada B4P 2R1 (Canada); Tong, Anthony Z., E-mail: anthony.tong@acadiau.ca [Department of Chemistry, Acadia University, Wolfville, NS, Canada B4P 2R6 (Canada)

    2013-11-15

    Highlights: • First membrane bioreactor treatment method for compost leachate. • No chemical additive or UV radiation source in this new biological method. • Removal rates of more than 99% for organics and ammonium were achieved. • Heavy metals were reduced by at least 82.7% except copper. - Abstract: Compost leachate forms during the composting process of organic material. It is rich in oxidizable organics, ammonia and metals, which pose a risk to the environment if released without proper treatment. An innovative method based on the membrane bioreactor (MBR) technology was developed to treat compost leachate over 39 days. Water quality parameters, such as pH, dissolved oxygen, ammonia, nitrate, nitrite and chemical oxygen demand (COD) were measured daily. Concentrations of caffeine and metals were measured over the course of the experiment using gas chromatography – mass spectrometry (GC/MS) and inductively coupled plasma – mass spectrometry (ICP–MS) respectively. A decrease of more than 99% was achieved for a COD of 116 g/L in the initial leachate. Ammonia was decreased from 2720 mg/L to 0.046 mg/L, while the nitrate concentration in the effluent rose to 710 mg/L. The bacteria in the MBR system adjusted to the presence of the leachate, and increased 4 orders of magnitude. Heavy metals were removed by at least 82.7% except copper. These successful results demonstrated the membrane bioreactor technology is feasible, efficient method for the treatment of compost leachate.

  10. Chemical analysis of soil and leachate from experimental wetland mesocosms lined with coal combustion products

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, C.; Mitsch, W.J. [Ohio State University, Columbus, OH (USA). Environmental Science Graduate Program and School of Natural Resources

    2001-08-01

    Small-scale (1 m{sup 2}) wetland mesocosm experiments were conducted over two consecutive growing seasons to investigate the effects on soil and leachate chemistry of using a recycled coal combustion product as a liner. The coal combustion product used as a liner consisted of flue gas desulfurization (FGD) by-products and fly ash. This paper provides the chemical characteristics of mesocosm soil and leachate after 2 yr of experimentation. Arsenic, Ca and pH were higher in FGD-lined mesocosm surface soil relative to unlined mesocosms. Aluminium was higher in the soils of unlined mesocosms relative to FGD-lined mesocosms. No significant difference of potentially phytotoxic B was observed between lined and unlined mesocosms in the soil. Higher pH, conductivity and concentrations of Al, B, Ca, K and S (SO{sub 4}-S) were observed in leachate from lined mesocosms compared with unlined controls while Fe, Mg and Mn were higher in leachate from unlined mesocosms. Concentrations of most elements analyzed in the leachate were below national primary and secondary drinking water standards after 2 yr of experimentation. Initially high pH and soluble salt concentrations measured in the leachate from the lined mesocosms may indicate the reason for early effects noted on the development of wetland vegetation in the mesocosms. 32 refs., 2 figs., 3 tabs.

  11. Effect of advanced oxidation processes (AOP's) on the toxicity of municipal landfill leachates

    Energy Technology Data Exchange (ETDEWEB)

    Slomczynska, B.; Slomczynski, T. [Inst. of Environmental Engineering Systems, Warsaw Univ. of Technology, Warsaw (Poland); Wasowski, J. [Inst. of Water Supply and Hydraulic Construction, Warsaw Univ. of Technology, Warsaw (Poland)

    2003-07-01

    The aim of present study was to assess the effect of AOP's (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using battery of tests. Advanced oxidation processes used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl{sub 3}. The effects of the pre-treatment of leachates using the method of coagulation with FeCl{sub 3} depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with O{sub 3} and H{sub 2}O{sub 2}/O{sub 3}, did not caused significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates. (orig.)

  12. An economic analysis of leachate purification through willow-coppice vegetation filters.

    Science.gov (United States)

    Rosenqvist, Håkan; Ness, Barry

    2004-09-01

    In this study an economic analysis of the purification of integrated solid waste treatment facility leachates through a willow-coppice (Salix) vegetation filter in southern Sweden was carried out. Calculations were based on the use of two computer models that were initially used in estimating a pump-and-pipe irrigation system for a 36-ha willow-coppice plantation to purify an average annual quantity of 195,000 m(3) of leachate with an average nitrogen content of 24 g/m(3). Results showed that facility leachates could be purified at US dollars 0.34/m(3) compared with US dollars 0.62/m(3) for that of conventional leachate treatment at a wastewater treatment plant. Furthermore, results revealed that the increased income from willow growing and sale of the biomass chips represented only a small factor in the overall cost of the purification technique--decreasing purification costs to US dollars 0.326/m(3). Sensitivity analyses also demonstrated that, because of the large leachate holding pond expense, only a fraction of facility leachate should be treated through a vegetation filter.

  13. Environmental risk index: A tool to assess the safety of dams for leachate

    Energy Technology Data Exchange (ETDEWEB)

    Colomer Mendoza, Francisco J. [Department of Mechanical Engineering and Construction, Universitat Jaume I, Av. de Vicente Sos Baynat s/n, 12071 Castellon (Spain)], E-mail: fcolomer@emc.uji.es; Gallardo Izquierdo, Antonio [Department of Mechanical Engineering and Construction, Universitat Jaume I, Av. de Vicente Sos Baynat s/n, 12071 Castellon (Spain)

    2009-02-15

    Dams for leachate store very toxic substances that contain a large amount of organic material and, probably, heavy metals; they therefore constitute an important threat to the environment. Existing models of environmental risk assessment for landfills do not take into consideration the specific risk that leachate dams may represent for the environment. In this paper a methodology to improve the environmental safety is presented according to the parameters used in their construction and management. In order to do that, the following characteristics of the dam must be known: (1) geotechnical stability, (2) erosion of downstream slope, (3) type of sealing of the dam, (4) overtopping probability, (5) volume of leachate stored inside the dam and (6) pollution load of leachate. Once these parameters have been calculated, they are transformed by means of rating curves into homogeneous units, so as to make it possible to operate between them. From the study and analysis of these parameters an environmental risk index for a dam for leachate can be calculated. If the environmental risk index exceeds an established value then it involves a dam for leachate with high environmental risk, therefore preventive measures in its design, construction and management would be necessary.

  14. Application of Catalytic Wet Air Oxidation to Treatment of Landfill Leachate on Co/Bi Catalyst

    Institute of Scientific and Technical Information of China (English)

    LI Hai-sheng; LIU Liang; ZHANG Rong; DONG De-ming; LIU Hong-liang; LI Yu

    2004-01-01

    Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and CODCr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows: the activated gas phase O2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO2 and H2O ultimately. In general, catalytic wet air oxidation over catalyst Co3O4/Bi2O3 was a very promising technique for the treatment of landfill leachate.

  15. Two Domain Flow Method for Leachate PredictionThrough Municipal Solid Waste Layers in Al–Amari Landfill Site

    Directory of Open Access Journals (Sweden)

    Hayder Mohammed Abdul–Hameed

    2008-01-01

    Full Text Available Existing leachate models over–or underestimates leachate generation by up to three orders of magnitude. Practical experiments show that channeled flow in waste leads to rapid discharge of large leachate volumes and heterogeneous moisture distribution. In order to more accurately predict leachate generation, leachate models must be improved. To predict moisture movement through waste, the two–domain PREFLO, are tested. Experimental waste and leachate flow values are compared with model predictions. When calibrated with experimental parameters, the PREFLO provides estimates of breakthrough time. In the short term, field capacity has to be reduced to 0.12 and effective storage and hydraulic conductivity of the waste must be increased to 0.12 and effective storage and hydraulic conductivity of the wasted must be increased to 0.2 and 2.2 cm/s respectively. In the long term, a new modeling approach must be developed to adequately describe the moisture movement mechanisms.

  16. Aerobic co-treatment of landfill leachate and domestic wastewater - are slowly biodegradable organics removed or simply diluted?

    Science.gov (United States)

    Campos, R; Ferraz, F M; Vieira, E M; Povinelli, J

    2014-01-01

    This study investigated the co-treatment of landfill leachate/domestic wastewater in bench-scale activated sludge (AS) reactors to determine whether the slowly biodegradable organic matter (SBOM) was removed rather than diluted. The AS reactors were loaded with mixtures of raw leachate and leachate that was pretreated by air stripping. The tested volumetric ratios were 0%, 0.2%, 2% and 5%. For all of the tested conditions, the reactors performed better when pretreated leachate was used rather than raw leachate, and the best volumetric ratio was 2%. The following removals were obtained: 97% for the biochemical oxygen demand (BOD5,20), 79% for total suspended solids, 77% for dissolved organic carbon and 84% for soluble chemical oxygen demand. Most of the pretreated leachate SBOM (65%) was removed rather than diluted or adsorbed into the sludge, as confirmed by Fourier transform infrared (FTIR) spectroscopy analyses.

  17. Enhancing treatment efficiency of swine wastewater by effluent recirculation in vertical-flow constructed wetland

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Livestock wastewater has been a major contributor to Chinese cultural eutrophication of surface waters. Constructed wetlands are under study as a best management practice to treat wastewater from dairy and swine operations, but the removal efficiency of pollutants is relatively low. Enhancing the treatment efficiency of livestock wastewater by effluent recirculation was investigated in a pilot-scale vertical-flow constructed wetland. The wetland system was composed of downflow and upflow stages, on which narrow-leafPhragmites communis and common reed Phragmites Typhia are planted, respectively; each stage has a dimension of4 m2 (2 m × 2 m). Wastewater from facultative pond was fed into the system intermittently at a flow rate of 0.4 m3/d. Recirculation rates of 0, 25%, 50%, 100% and 150% were adopted to evaluate the effect of the recirculation rate on pollutants removal. It shows that with effluent recirculation the average removal efficiencies of NH4-N, biological oxygen demand (BOD5) and suspended solids(SS)obviously increase to 61.7%, 81.3%, and 77.1%, respectively, in comparison with the values of 35.6%, 50.2%, and 49.3% without effluent recirculation. But the improvement of TP removal is slight, only from 42.3% to 48.9%. The variations of NH4-N, dissolved oxygen(DO) and oxidation-reduction potential(ORP) of inflow and outflow reveal that the adoption of effluent recirculation is beneficial to the formation of oxide environment in wetland. The exponential relationships with excellent correlation coefficients (R2 >0.93)are found between the removal rates of NH4-N and BOD5 and the recirculation rates. With recirculation the pH value of the outflow decreases as the alkalinity is consumed by gradually enhanced nitrification process. When recirculation rate is kept constant 100%, the ambient temperature appears to affect NH4-N removal, but does not have significant influence on BOD5 removal.

  18. EFFICIENCY OF PRE-TREATMENT OF LEACHATE FROM MUNICIPAL WASTE DUMPS BY GASEOUS DESORPTION (STRIPPING OF AMMONIA

    Directory of Open Access Journals (Sweden)

    Justyna Koc-Jurczyk

    2017-05-01

    Full Text Available The paper studies the efficiency of pre-treatment of landfill leachate by gaseous desorption of ammonia. The research was done on a municipal non-hazardous waste dump in Krosno (Sub-Carpathian Province, Poland. The pretreatment provided a favorable BOD5/COD ratio in leachate. Also concentrations of 16 PAHs and heavy metals did not exceed the legal limits. However, gaseous desorption of ammonia was insufficiently efficient in recovering ammonia nitrogen from leachate.

  19. Studies on Hydroxyl Radical Formation and Correlated Photoflocculation Process Using Degraded Wood Leachate as a CDOM Source

    OpenAIRE

    Luni eSun; Kenneth eMopper

    2016-01-01

    The iron-poor leachate from decaying wood can be an important source of colored dissolved organic matter (CDOM) in natural waters. In this study, we examined hydroxyl radical (•OH) formation with respect to photoreactivity of wood leachate DOM, the Fenton reaction, and photoflocculation. The relationship of •OH photoproduction rate and leachate optical properties (UV-visible absorption and fluorescence excitation-emission matrices (EEMS) coupled with PARAFAC analysis) were studied during irra...

  20. Noscapine recirculates enterohepatically and induces self-clearance.

    Science.gov (United States)

    Mukkavilli, Rao; Gundala, Sushma R; Yang, Chunhua; Jadhav, Gajanan R; Vangala, Subrahmanyam; Reid, Michelle D; Aneja, Ritu

    2015-09-18

    Noscapine (Nos), an antitussive benzylisoquinoline opium alkaloid, is a non-toxic tubulin-binding agent currently in Phase II clinical trials for cancer chemotherapy. While preclinical studies have established its tumor-inhibitory properties in various cancers, poor absorptivity and rapid first-pass metabolism producing several uncharacterized metabolites for efficacy, present an impediment in translating its efficacy in humans. Here we report novel formulations of Nos in combination with dietary agents like capsaicin (Cap), piperine (Pip), eugenol (Eu) and curcumin (Cur) known for modulating Phase I and II drug metabolizing enzymes. In vivo pharmacokinetic (PK), organ toxicity evaluation of combinations, microsomal stability and in vitro cytochrome P450 (CYP) inhibition effects of Nos, Cap and Pip using human liver microsomes were performed. Single-dose PK screening of combinations revealed that the relative exposure of Nos (2 μg h/mL) was enhanced by 2-fold (4 μg h/mL) by Cap and Pip and their plasma concentration-time profiles showed multiple peaking phenomena for Nos indicating enterohepatic recirculation or differential absorption from intestine. CYP inhibition studies confirmed that Nos, Cap and Pip are not potent CYP inhibitors (IC50>1 μM). Repeated oral dosing of Nos, Nos+Cap and Nos+Pip showed lower exposure (Cmax and AUClast) of Nos on day 7 compared to day 1. Nos Cmax decreased from 3087 ng/mL to 684 ng/mL and AUClast from 1024 ng h/mL to 508 ng h/mL. In presence of Cap and Pip, the decrease in Cmax and AUClast of Nos was similar. This may be due to potential enzyme induction leading to rapid clearance of Nos as the trend was observed in Nos alone group also. The lack of effect on intrinsic clearance of Nos suggests that the potential drug biotransformation modulators employed in this study did not contribute toward increased exposure of Nos on repeated dosing. We envision that Nos-induced enzyme induction could alter the therapeutic efficacy of co

  1. Effects of leachate accumulation on landfill stability in humid regions of China.

    Science.gov (United States)

    Jianguo, Jiang; Yong, Yang; Shihui, Yang; Bin, Ye; Chang, Zhang

    2010-05-01

    Leachate levels are important to landfill stability and safety. High leachate or water levels often lead to landfill instability, which can cause accidents. Here a case study of a landfill located in a humid region of southern China is presented. Leachate distribution and quality were systematically analyzed, and the effect of leachate level on waste-mass stability was assessed. Boreholes were drilled in the field, samples were analyzed in the laboratory, and a simulation was performed. In addition, the safety and stability of the landfill was evaluated. The leachate level in the landfill was 9-19m, which was higher than the top of the dam crest (8-20m). Leachate accounted for more than 1/4 of the total landfill storage capacity. The contaminant concentration of the leachate samples collected directly from the waste body was very high, with large variation among the samples. The mean concentrations of NH(3)-N, BOD, and COD from the waste body were 5404, 14,136, and 22,691mg/L, nearly 2.7, 2.4, and 1.8 times the mean concentrations in the leachate pond, respectively. Three series of shear strength parameters were used in a slope stability analysis, and a limit equilibrium method was used to calculate the factor of safety (Fs). The analysis showed that Fs could be affected by potential anisotropy in the shear strength of the waste. The minimum values of Fs corresponding to series I were 1.84 and 1.17 for units capital I, Ukrainian and II, respectively. The Fs value of unit II was significantly lower than the safe design value (1.25). In addition, Fs decreased with increase in the normalized height of the leachate level, h/H, where h is the height of the leachate mound and H is the maximum thickness of the landfill. If the h/H values of units I and II are kept below 50% and 40%, respectively, a safe design value of 1.25 for Fs can be guaranteed. Therefore, some measures to prevent risk should be considered. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Comparative evaluation of leachate pollution index of MSW landfill site of Kolkata with other metropolitan cities of India.

    Science.gov (United States)

    Motling, Sanjay; Dutta, Amit; Mukherjee, S N; Kumar, Sunil

    2013-07-01

    The uncontrolled tipping of mixed urban solid waste in landfill site causes serious negative impacts on the environment. The major issue in this context is the generation of leachate which possesses potential of polluting freshwater ecosystem including groundwater besides associated health hazards and depletion of soil fertility. In this context, a pseudo computation quantitative tool, known as leachate pollution index (LPI), has been developed by some researchers for scaling pollution potential of landfill site owing to emergence of leachate. This paper. deals with the assessment of leachate quality of existing landfill site of Kolkata situated at Dhapa waste dumping ground through evaluation of the LPI from experimental analysis of leachate. The leachate was collected from this site in different seasons. 18 parameters were tested with real leachate samples in the Environmental Engineering Laboratory of Civil Engineering Department of Jadavpur University Kolkata. The results exhibited a very high value of organic pollutants in the leachate with COD as 21,129 mg/L and also values of TDS, Fe2+, Cr, Zn, chloride and ammonical nitrogen. The LPI value of Kolkata landfill site at Dhapa was estimated and also compared with leachate quality data of other metropolitan cities viz. Mumbai, Delhi, Chennai as available in literatures. It is found that LPI of the Kolkata landfill site is highest compared to all other landfill sites of other metropolitan cities in India.

  3. Apparent Formation Factor for Leachate-Saturated Waste and Sediments: Examples from the USA and China

    Institute of Scientific and Technical Information of China (English)

    Philip J Carpenter; Ding Aizhong; Cheng Lirong; Liu Puxin; Chu Fulu

    2009-01-01

    The formation factor relates bulk resistivity to pore fluid resistivity in porous materials. Understanding the formation factor is essential in using electrical and electromagnetic methods to monitor leachate accumulations and movements both within and around landfills. Specifically, the formation factor allows leachate resistivity, the degree of saturation, and, possibly, even the hydraulic conductivity of the waste to be estimated from non-invasive surface measurements. In this study, apparent formation factors are computed for three landfills with different types of waste as well as sediments contaminated by landfill leachate. Resistivity soundings at the closed Mallard North landfill in suburban Chicago (Illinois, USA) mapped leachate surfaces that were confirmed by monitoring wells. The resistivity of leachate-saturated waste from resistivity sounding inversions was then divided by the leachate resistivity values measured in-situ to compute apparent formation factors (Fa) ranging from 1.6 to 4.9. A global Fa of 3.0±1.9 was computed for the entire monitored portion of this landfill At a nearby mixed laboratory waste landfill, a 2D inverted resistivity section was used to compute an Fa of 2.9. Finally, a distinctly different Fa value of 10.6±2.8 was computed for leachate-saturated retorted oil and organic compounds. The Fa for aquifers containing contaminated groundwater fall in the same range as aquifers with normal groundwater, 1.7-3.9. However, models from inverted sounding curves over these contaminated areas exhibit unusually low resistivity layers, which may be diagnostic of contamination.

  4. Delineation of a landfill leachate plume using shallow electromagnetic and ground-penetrating radar surveys

    Energy Technology Data Exchange (ETDEWEB)

    Nobes, D.C.; Armstrong, M.J. [Univ. of Canterbury, Christchurch (New Zealand); Broadbent, M. [Broadbent (Michael), Christchurch (New Zealand)

    1994-12-31

    Leachate plumes are often more electrically conductive than the surrounding host pore waters, and thus can be detected using shallow electromagnetic (EM) methods. The depth of penetration of ground penetrating radar (GPR) is controlled to a large extent by the electrical conductivity. Conductive leachate plumes will appear as ``blank`` areas in the radar profiles, because the radar energy is more severely attenuated in the region of the leachate plume. The authors present here the results of EM and GPR Surveys carried out in an area adjacent to a landfill site. Previous resistivity surveys indicated the presence of a leachate plume originating from an early stage of the landfill operation. The shallow EM and GPR surveys were carried out, in part, to confirm and refine the resistivity results, and to delineate the spatial extent of the plume. The surficial sediments are coastal sands, and the dune topography has an effect on the EM results, even though the variations in elevation are, in general, no more than 3 m. Besides the leachate plume, numerous conductivity highs and lows are present, which are at least coarsely correlated with topographic lows and highs. Following the empirical procedure outlined by Monier-Williams et al. (1990), the topographic effects have been removed, and the plume is better isolated and delineated. A possible second, weaker leachate plume has been identified, emanating from the current landfill operation. The second plume may follow a channel that was masked by the overlying dune sands. The leading edge of the primary leachate plume is moving to the south-southeast at a rate of 14 to 15 m/yr.

  5. Optimizing the treatment of landfill leachate by conventional Fenton and photo-Fenton processes

    Energy Technology Data Exchange (ETDEWEB)

    Hermosilla, Daphne, E-mail: dhermosilla@quim.ucm.es [Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Cortijo, Manuel [U.D. Operaciones Basicas, Departamento de Ingenieria Forestal, E.T.S.I. Montes, Universidad Politecnica de Madrid, Avda. Ramiro de Maeztu s/n, 28040 Madrid (Spain); Huang, Chin Pao [Department of Civil and Environmental Engineering, 352C DuPont Hall, University of Delaware, Newark, DE 19716 (United States)

    2009-05-15

    Landfill, a matured and economically appealing technology, is the ultimate approach for the management of municipal solid wastes. However, the inevitable generation of leachate from landfill requires further treatment. Among the various leachate treatment technologies available, advanced oxidation processes (AOPs) are among powerful methods to deal with the refractory organic constituents, and the Fenton reagent has evolved as one promising AOPs for the treatment of leachates. Particularly, the combination of UV-radiation with Fenton's reagent has been reported to be a method that allows both the photo-regeneration of Fe{sup 2+} and photo-decarboxylation of ferric carboxylates. In this study, Fenton and photo-Fenton processes were fine tuned for the treatment of leachates from the Colmenar Viejo (Madrid, Spain) Landfill. Results showed that it is possible to define a set of conditions under which the same COD and TOC removals (approx 70%) could be achieved with both the conventional and photo-Fenton processes. But Fenton process generated an important quantity of iron sludge, which will require further disposal, when performed under optimal COD removal conditions. Furthermore conventional Fenton process was able to achieve slightly over an 80% COD removal from a 'young' leachate, while for 'old' and 'mixed' leachates was close to a 70%. The main advantage showed by the photo-assisted Fenton treatment of landfill leachate was that it consumed 32 times less iron and produced 25 times less sludge volume yielding the same COD removal results than a conventional Fenton treatment.

  6. Effect of leachate recycling and inoculation on the biochemical characteristics of municipal refuse in landfill bioreactors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Activity development of key groups of enzymes involved in municipal refuse decomposition was measured in laboratory landfill hioreactors with and without leachate recycling and inoculation for about 210 days.The results showed that the enzymes (amylase,protease,cellulase,lipase and pectinase ) were present in fresh refuse but at low values and positively affected hy leachate recycling and refuse inoculation.The total average of cellulase activity in digesters D3 operated with leachate recycling but no inoculation,D4 and D5 operated with leachate recycling and inoculation was much higher than that in digesters D1 and D2 without leachate recycling and inoculation by 88%-127%,117%-162% and 64%-98%.The total average of protease activity was higher in digester D4 than that in digesters D1,D2,D3and D5 by 63%,39%,24% and 24%,respectively,and the positive effect of leachate recycli.ng and inoculation on protease activity of landfilled refuse mainly was at the first two months.The total average of amylase activity was higher in digesters D3,D4 and D5 than that in digesters D1 and D2 by 83%-132%,96%-148% and 81%-129%.During the early phase of incubation,the stimulatory effect of inoculation on lipase activity was measured,but refuse moisture was the main factor affecting lipase activity of landfilled refuse.The inoculation,initial and continuous inoculation of microorganisms existing in leachate,was the mainly stimulatory factor affecting pectinase activity of landfilled refuse.

  7. THE STRIPPING OF AMMONIA FROM LANDFILL LEACHATE IN PLUG FLOW REACTORS

    Directory of Open Access Journals (Sweden)

    Danuza Costa Campos

    2010-10-01

    Full Text Available The leachate is a highly liquid polluting, considering, besides high concentrations of ammonia nitrogen. Treating leachate is a very difficult task once its composition is very complex. A king of treatment that is being developed is the stripping of ammonia where this chemical will be removed from the leachate by mass transfer of the liquid phase to gas. Therefore, this paper addressed to study the ammonia stripping process in leachates liquids using plug-flow reactors in series. In order to accomplish the experimental part four plugflow reactors in series were build, with an average height of 50 centimeters, without forced air supplier and without leachate pH adjustment. The leachate sample used was from the metropolitan landfill of Joao Pessoa city, which was collected and transported to the EXTRABES laboratory and made the physicochemical characterization. The experimental monitoring system consisted of four distinct phases, with applied superficial loads of 450, 500, 600 and 700 kg NH4+ ha-1 day-1, hydraulic detention time equal to 65, 60, 50 and 38 days, and it was obtained an average efficiency of ammonia nitrogen removal around 96.1%, 99.7%, 99.5% and 98.5% respectively. It was found that the removal efficiency of NH3 was satisfactory in all phases, however, the kinetic study showed that the higher the surface charge applied to the reactors, the higher the rate constant for removal of NH3 stripping process. Thus we can conclude that the process of stripping ammonia from landfill leachate may be done in plug-flow reactors in series, with an average depth of 50 cm, due to provide high removal efficiency of ammonia nitrogen, with low operating costs.

  8. Method and apparatus for control of coherent synchrotron radiation effects during recirculation with bunch compression

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David R; Tennant, Christopher

    2015-11-10

    A modulated-bending recirculating system that avoids CSR-driven breakdown in emittance compensation by redistributing the bending along the beamline. The modulated-bending recirculating system includes a) larger angles of bending in initial FODO cells, thereby enhancing the impact of CSR early on in the beam line while the bunch is long, and 2) a decreased bending angle in the final FODO cells, reducing the effect of CSR while the bunch is short. The invention describes a method for controlling the effects of CSR during recirculation and bunch compression including a) correcting chromatic aberrations, b) correcting lattice and CSR-induced curvature in the longitudinal phase space by compensating T.sub.566, and c) using lattice perturbations to compensate obvious linear correlations x-dp/p and x'-dp/p.

  9. DISPERSION COMPENSATION CFBG IN 100km 10Gbit/s RECIRCULATING SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    Yang Aiying; Wang Ziyu; Zhang Zhaoyi; Chen Zhangyuan; Wu Deming

    2003-01-01

    A 10 Gbit/s recirculating system is configured with Chirped Fiber Bragg Grating (CFBG) for the dispersion compensation. For the first time, the transmission distance in the loop reaches 1000km with bit error rate of 10-9. The effect of the group delay ripple of the fiber grating is also investigated in the recirculating systems, and it is shown that the transmission distance is limited to 4 cycles (4× 167.1km ) in the loop with the power penalty fluctuation below 1.0dB. Thus the group delay ripple should be reduced to allow for the wavelength drift of ±5GHz.At the end of this letter, the principles are given for designing long haul recirculating systems with dispersion compensation CFBG.

  10. Controlled reattachment in separated flows: a variational approach to recirculation length reduction

    CERN Document Server

    Boujo, E

    2014-01-01

    A variational technique is used to derive analytical expressions for the sensitivity of recirculation length to steady forcing in separated flows. Linear sensitivity analysis is applied to the two-dimensional steady flow past a circular cylinder for Reynolds numbers $40 \\leq Re \\leq 120$, both in the subcritical and supercritical regimes. Regions which are the most sensitive to volume forcing and wall blowing/suction are identified. Control configurations which reduce the recirculation length are designed based on the sensitivity information, in particular small cylinders used as control devices in the wake of the main cylinder, and fluid suction at the cylinder wall. Validation against full non-linear Navier-Stokes calculations shows excellent agreement for small-amplitude control. The linear stability properties of the controlled flow are systematically investigated. At moderate Reynolds numbers, we observe that regions where control reduces the recirculation length correspond to regions where it has a stab...

  11. Thermodynamic Model for Updraft Gasifier with External Recirculation of Pyrolysis Gas

    Directory of Open Access Journals (Sweden)

    Fajri Vidian

    2016-01-01

    Full Text Available Most of the thermodynamic modeling of gasification for updraft gasifier uses one process of decomposition (decomposition of fuel. In the present study, a thermodynamic model which uses two processes of decomposition (decomposition of fuel and char is used. The model is implemented in modification of updraft gasifier with external recirculation of pyrolysis gas to the combustion zone and the gas flowing out from the side stream (reduction zone in the updraft gasifier. The goal of the model obtains the influences of amount of recirculation pyrolysis gas fraction to combustion zone on combustible gas and tar. The significant results of modification updraft are that the increases amount of recirculation of pyrolysis gas will increase the composition of H2 and reduce the composition of tar; then the composition of CO and CH4 is dependent on equivalence ratio. The results of the model for combustible gas composition are compared with previous study.

  12. Recurrent amoebic gill infestation in rainbow trout cultured in a semiclosed water recirculation system

    Science.gov (United States)

    Noble, A.C.; Herman, R.L.; Noga, E.J.; Bullock, G.L.

    1997-01-01

    Five lots of commercially purchased juvenile rainbow trout Oncorhynchus mykiss (17-44 g) stocked in a continuous-production water recirculation system became infested with gilt amoebae. The amoebae were introduced into the recirculation system, as evidenced by their presence on gills of fish held in quarantine tanks. Based on their morphology, as seen in histological sections and by electron microscopy, the amoebae appeared to be more closely related to the family Cochliopodiidae than to other taxa of free living amoebae. Attempts to culture the amoebae in different media, at different temperatures of incubation, and in fish cell culture were not successful. Initial treatment of the recirculation system with formalin at 167 parts per million (ppm) for 1 h eliminated amoebae from the gills. Subsequent treatments of the entire system with formalin at 50-167 ppm reduced the intensity of further infestations.

  13. Saponification pretreatment and solids recirculation as a new anaerobic process for the treatment of slaughterhouse waste.

    Science.gov (United States)

    Affes, R; Palatsi, J; Flotats, X; Carrère, H; Steyer, J P; Battimelli, A

    2013-03-01

    Different configurations of anaerobic process, adapted to the treatment of solid slaughterhouse fatty waste, were proposed and evaluated in this study. The tested configurations are based on the combination of anaerobic digestion with/without waste saponification pretreatment (70 °C during 60 min) and with/without recirculation of the digestate solid fraction (ratio=20% w/w). After an acclimation period of substrate pulses-feeding cycles, the reactors were operated in a semi-continuous feeding mode, increasing organic loading rates along experimental time. The degradation of the raw substrate was shown to be the bottleneck of the whole process, obtaining the best performance and process yields in the reactor equipped with waste pretreatment and solids recirculation. Saponification promoted the emulsification and bioavailability of solid fatty residues, while recirculation of solids minimized the substrate/biomass wash-out and induced microbial adaptation to the treatment of fatty substrates.

  14. Control oriented modeling of ejector in anode gas recirculation solid oxygen fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Yinhai, E-mail: yinhai.zhu@gmail.co [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Li Yanzhong, E-mail: yzli-epe@mail.xjtu.edu.c [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Cai Wenjian [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2011-04-15

    A one-equation model is proposed for fuel ejector in anode gas recirculation solid oxide fuel cell (SOFC) system. Firstly, the fundamental governing equations are established by employing the thermodynamic, fluid dynamic principles and chemical constraints inside the ejector; secondly, the one-equation model is derived by using the parameter analysis and lumped-parameter method. Finally, the computational fluid dynamics (CFD) technique is employed to obtain the source data for determining the model parameters. The effectiveness of the model is studied under a wide range of operation conditions. The effect of ejector performance on the anode gas recirculation SOFC system is also discussed. The presented model, which only contains four constant parameters, is useful in real-time control and optimization of fuel ejector in the anode gas recirculation SOFC system.

  15. Investigation of hydrocarbon oil transformation by gliding arc discharge: comparison of batch and recirculated configurations

    Science.gov (United States)

    Whitehead, J. Christopher; Prantsidou, Maria

    2016-04-01

    The degradation of liquid dodecane was studied in a gliding arc discharge (GAD) of humid argon or nitrogen. A batch or recirculating configuration was used. The products in the gaseous and liquid phase were analysed by infrared and chromatography and optical emission spectroscopy was used to identify the excited species in the discharge. The best degradation performance comes from the use of humid N2 but a GAD of humid argon produces fewer gas-phase products but more liquid-phase end-products. A wide range of products such as heavier saturated or unsaturated hydrocarbons both aliphatic and aromatic, and oxidation products mainly alcohols, but also aldehydes, ketones and esters are produced in the liquid-phase. The recirculating treatment mode is more effective than the batch mode increasing the reactivity and changing the product selectivities. Overall, the study shows promising results for the organic liquid waste treatment, especially in the recirculating mode.

  16. Optimized evaporation technique for leachate treatment: Small scale implementation.

    Science.gov (United States)

    Benyoucef, Fatima; Makan, Abdelhadi; El Ghmari, Abderrahman; Ouatmane, Aziz

    2016-04-01

    This paper introduces an optimized evaporation technique for leachate treatment. For this purpose and in order to study the feasibility and measure the effectiveness of the forced evaporation, three cuboidal steel tubs were designed and implemented. The first control-tub was installed at the ground level to monitor natural evaporation. Similarly, the second and the third tub, models under investigation, were installed respectively at the ground level (equipped-tub 1) and out of the ground level (equipped-tub 2), and provided with special equipment to accelerate the evaporation process. The obtained results showed that the evaporation rate at the equipped-tubs was much accelerated with respect to the control-tub. It was accelerated five times in the winter period, where the evaporation rate was increased from a value of 0.37 mm/day to reach a value of 1.50 mm/day. In the summer period, the evaporation rate was accelerated more than three times and it increased from a value of 3.06 mm/day to reach a value of 10.25 mm/day. Overall, the optimized evaporation technique can be applied effectively either under electric or solar energy supply, and will accelerate the evaporation rate from three to five times whatever the season temperature. Copyright © 2016. Published by Elsevier Ltd.

  17. Ozonation of refractory chemicals in leachate with hydrogen peroxide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nearly 97% of organic chemicals in Hong Kong leachatecould be effectively removed by the UASB(upflow anaerobic sludgeblanket) process followed by the Fenton coagulation. The COD ofleachate was lowered from an average of 12900 mg/L to 1440 mg/hafter the UASB treatment, and was further lowered to 394 mg/L afterthe Fenton coagulation. The remaining refractory residues could befurther removed by ozonation with the addition of H2O2. Theozonation for the supernatant of the Fenton coagulation was mosteffective at pH 7-8, with the addition of 300 mg/L of H2O2, and 30min of reaction. The final effluent contained only 85 mg/L of CODand l0 mg/L of BOD5. On the other hand, direct ozonation of UASBeffluent lowered the COD to 905 mg/L and BOD5 to l03 mg/L.Ozonation improved the biodegradability of the organic residues,and also converted part of organic-N in the leachate into NH3-N andNO3--N.

  18. Pretreated waste landfilling: relation between leachate characteristics and mechanical behaviour.

    Science.gov (United States)

    Boni, Maria Rosaria; Chiavola, Agostina; Sbaffoni, Silvia

    2006-01-01

    The present paper presents a part of a wider research effort aiming at studying the long-term behaviour of different pre-treated wastes once landfilled; in particular, this paper deals with the analysis of settlements and their correlation with the main leachate biochemical parameters (BOD, COD and pH). The municipal solid waste organic fraction (MSWOF) and bottom ash (BA) from incineration of municipal solid waste (MSW) were considered in the study and used to set up different semi-pilot landfill plants. Particularly, the FT plant contained 90 days aerobically biostabilized MSWOF, the FP plant was filled with 15 days aerobically biostabilized MSWOF and the MX plant with a 30-70% (by weight) mixture of BA and the same MSWOF used in the FP plant. The data obtained showed a faster mechanical and biological stabilization of the FT and MX plants, due to the less biodegradable organic fraction content initially present in the FT plant and to the presence of BA, having a stabilizing effect, in the MX plant. Besides, similar behaviour of FT and MX was observed, and also a strong correlation between the settlement and the biochemical parameters time profiles was identified.

  19. An Autopsy of Nanofiltration Membrane Used for Landfill Leachate Treatment

    Directory of Open Access Journals (Sweden)

    Ibrahim Demir

    2015-01-01

    Full Text Available Komurcuoda leachate treatment plant, Istanbul, which consists of membrane bioreactor (MBR and nanofiltration (NF system, faced rapid flux decline in membranes after 3-year successful operation. To compensate rapid flux decline in membranes, the fouled membranes were renewed but replacement of the membranes did not solve the problem. To find the reasons and make a comprehensive analysis, membrane autopsy was performed. Visual and physical inspection of the modules and some instrumental analysis were conducted for membrane autopsy. Membranes were found severely fouled with organic and inorganic foulants. Main foulant was iron which was deposited on surface. The main reason was found to be the changing of aerator type of MBR. When surface aerators were exchanged with bottom diffusers which led to increasing of dissolved oxygen (DO level of the basin, iron particles were oxidized and they converted into particulate insoluble form. It was thought that probably this insoluble form of the iron particles was the main cause of decreased membrane performance. After the diagnosis, a new pretreatment alternative including a new iron antiscalant was suggested and system performance has been recovered.

  20. Contribution of seawater recirculation to submarine groundwater discharge and related nutrient fluxes in two tropical bays

    Science.gov (United States)

    Vautier, Camille; Dulaiova, Henrietta

    2017-04-01

    Hawaiian coastal waters suffer from excess terrestrial nutrient loading, most of which comes from submarine groundwater discharge (SGD). This study quantifies and distinguishes the role of the fresh terrestrial and tidally pumped salt water components of SGD into the nearshore zone of two reefs on the island of Oahu: Maunalua Bay and Kāneohe Bay. The two components of SGD are characterized using isotopic techniques, and the study mainly focuses on the less understood recirculation component. A two-step approach is implemented: first, a conceptual model of groundwater circulation is established; second, nutrient fluxes associated with seawater recirculation are quantified. Groundwater circulation through the beach berm is quantified and characterized using 222Rn and 224Ra activity measurements. Nutrient fluxes are obtained by coupling nutrient concentration measurements and discharge estimates. The isotopic signatures inform us about the influence of the tidal cycle on groundwater circulation. 222Rn, 224Ra, and δ18O isotopes are used to derive apparent ages of the infiltrated seawater and allow us to quantify recirculation rates. The method is also complemented with the use of silicate concentration as tracers of the recirculation process. The trends in apparent ages observed in pore water in Maunalua match previously published conceptual groundwater circulation models and show a sequentially aging pore water circulation loop. However, the ages obtained in Kāneohe suggest a different tidal pumping dynamic that lacks a circulation loop, perhaps resulting from the absence of freshwater discharge. Derived nutrient fluxes show that the autochthonous production of inorganic nitrogen and phosphorus that occurs during seawater recirculation has a significant impact on nutrient cycles in the nearshore areas of the bays. This result suggests that seawater recirculation should be taken into account in biogeochemical studies of coastal areas.

  1. The Two Branches of the Recirculation of Atlantic Water in Fram Strait

    Science.gov (United States)

    von Appen, Wilken-Jon; Schauer, Ursula; Hattermann, Tore; Albretsen, Jon

    2016-04-01

    The Fram Strait between Greenland and Svalbard is one of the two gateways by which warm Atlantic Water enters the Arctic Ocean providing oceanic heat. The West Spitsbergen Current advects the warm water northward in the eastern Fram Strait. However, only some of this water stays in the boundary current and enters the Arctic Ocean. Another part leaves the boundary current and flows westward across Fram Strait before turning southward in the East Greenland Current. This recirculation of Atlantic Water corresponds with the ice edge in Fram Strait and the two likely depend on each other. Here we present results from a high resolution regional numerical model that shows the recirculation to consist of two branches. The northern branch depends on eddy fluxes while the southern branch exhibits less high frequency variability. We also present a compilation of different observational data in the center of Fram Strait around 0°EW that give insight into the structure of the southern recirculation branch near the ice edge. A glider section resolves the small horizontal scale over which the geostrophic flow occurs. Several meridional CTD sections capture the differences and similarities between different summers. Moorings and Argo floats provide information in winter as well. These observations are compared to the representation of the recirculation in the numerical model. We show that the southern recirculation occurs over a small horizontal distance of about 20km in the vicinity of 79°N and is significantly stronger in winter than in summer. While there is cold freshwater at the surface north of the front, the temperature down to 500m is much higher in the recirculation than further south.

  2. 回灌频率对联合型生物反应器填埋场的影响研究%Effect of Recirculation Frequency in Anaerobic-semiaerobic Bioreactor Landfill

    Institute of Scientific and Technical Information of China (English)

    陈馨; 李启彬; 刘丹; 韩智勇

    2013-01-01

    为解决厌氧型生物反应器填埋场中氨氮积累问题,加速填埋场的稳定化进程,将厌氧生物反应器填埋场和准好氧矿化垃圾反应床串联.实验设置了1个厌氧型生物反应器填埋场(ANBL1#)作为参照组,2个厌氧-准好氧联合型生物反应器填埋场(AN-SABL2#、AN-SABL 3#)作为对照组,以研究不同回灌频率下AN-SABL的稳定化规律.研究结果表明:AN-SABL2#、AN-SABL3#可缩短酸化时间,渗滤液的pH值分别在94周、98周升至大于7,而ANBL1#渗滤液的pH值直至100周仍小于7.AN-SABL系统可有效降解渗滤液COD浓度,实验进行到100周左右时,AN-SABL2#、AN-SABL3#系统中厌氧柱D2、D3柱COD浓度仅为ANBL1#系统中厌氧柱D1柱的40.63%、12.5%,而准好氧柱对渗滤液COD的去除率大部分在95%以上.AN-SABL系统能缓解厌氧型生物反应器填埋场中氨氮积累问题,这主要依靠矿化垃圾床良好的生物脱氮作用,厌氧柱D1、D2、D3中NH3-N含量总体趋势为:NH3-ND1>NH3-Nm,NH3-ND1>NH3-ND2,准好氧d2、d3柱氨氮去除率均在90%以上,且厌氧-准好氧联合型生物反应器填埋场(AN-SABL)在实验产酸阶段低回灌频率(3d/次)对氨氮的去除有利,而后期高回灌频率(1 d/次)更有利.%Anaerobic bioreactor landfill with a semi-aerobic aged refuse bioreactor was studied for reducing high concentration ammonia nitrogen cumulated in anaerobic bioreactor landfill, in order to accelerate the stabilization of landfill ANBL1#, a simulated anaerobic bioreactor, as the reference group and two simulated anaerobic-semiaerobic bioreactors (AN-S ABL2#, AN-SABL3#) as control groups were devised, for studying the stabilization of AN -SABL operated at different leachate recirculation frequencies. Results indicated that leachate pH value in ANBL1# remained less than 7 until the 100th week. By contrast, the pH value of leachate in AN-SABL2# and AN-SABL3# both rose to more than 7 after 94 weeks and 98 weeks respectively

  3. Analysis of bio-obtainable endocrine disrupting metals in river water and sediment, sewage influent/effluent, sludge, leachate, and concentrated leachate, in the irish midlands shannon catchment.

    LENUS (Irish Health Repository)

    Reid, Antoinette M

    2009-01-01

    The application of an acid digestion and subsequent solid-phase extraction (SPE) procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs) in a variety of solid and liquid matrices. These included (solid) river sediment, leachate sediment and sewage sludge and also (liquid) river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and manganese (Mn), after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS). Mercury (Hg) in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS). For sewage sludge maximum values (mg\\/kg(dw)) of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg\\/kg(dw)) of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  4. Analysis of bio-obtainable endocrine disrupting metals in river water and sediment, sewage influent/effluent, sludge, leachate, and concentrated leachate, in the irish midlands shannon catchment.

    Science.gov (United States)

    Reid, Antoinette M; Brougham, Concepta A; Fogarty, Andrew M; Roche, James J

    2009-01-01

    The application of an acid digestion and subsequent solid-phase extraction (SPE) procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs) in a variety of solid and liquid matrices. These included (solid) river sediment, leachate sediment and sewage sludge and also (liquid) river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), zinc (Zn), and manganese (Mn), after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS). Mercury (Hg) in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS). For sewage sludge maximum values (mg/kg(dw)) of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg/kg(dw)) of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  5. Effect of room air recirculation delay on the decay rate of tracer gas concentration

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, A.R.; Gadgil, A.J.; Lorenzetti, D.M.

    2004-05-01

    Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation. The analysis shows that failing to account for delays can lead to under- or over-estimates of the fresh air supply, depending on whether the decay rate calculation includes the duct volume.

  6. Performance of the prototype gas recirculation system with built-in RGA for INO RPC system

    Energy Technology Data Exchange (ETDEWEB)

    Bhuyan, M. [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Datar, V.M. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Joshi, A. [Alpha Pneumatics, 11-Krishna Kutir, Madanlal Dhingra Road, Thane 400602 (India); Kalmani, S.D., E-mail: kalmani@tifr.res.in [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Mondal, N.K. [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Rahman, M.A. [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Satyanarayana, B.; Verma, P. [Department of High Energy Physics, Tata Institute of Fundamental Research, Mumbai 400005 (India)

    2012-01-01

    An open loop gas recovery and recirculation system has been developed for the INO RPC system. The gas mixture coming from RPC exhaust is first desiccated by passing through molecular sieve (3 Angstrom-Sign +4 Angstrom-Sign ). Subsequent scrubbing over basic active alumina removes toxic and acidic contaminants. The Isobutane and Freon are then separated by diffusion and liquefied by fractional condensation by cooling up to -26{sup Ring-Operator }C. A Residual Gas Analyser (RGA) is being used in the loop to study the performance of the recirculation system. The results of the RGA analysis will be discussed.

  7. Cleaning and recirculation of perfluorohexane ($C_{6} F_{14}$) in the STAR-RICH detector

    CERN Document Server

    Andrés, Yu; Cozza, D; Davenport, M; De Cataldo, G; Dell'Olio, L; Di Bari, D; Di Mauro, A; Dunlop, J C; Finch, E; Fraissard, Daniel; Franco, A; Gans, J; Ghidini, B; Harris, J W; Horsley, M; Kunde, G J; Lasiuk, B; Lesenechal, Y; Majka, R D; Martinengo, P; Morsch, Andreas; Nappi, E; Paic, G; Piuz, François; Posa, F; Raynaud, J; Salur, S; Sandweiss, J; Santiard, Jean-Claude; Satinover, J; Schyns, E M; Smirnov, N; Van Beelen, J; Williams, T D; Xu, Z

    2002-01-01

    A RICH detector with a CsI photo-cathode and liquid perfluorohexane radiator has been installed in the STAR experiment at RHIC. The liquid is continuously cleaned and distributed to a quartz containment vessel within the detector by a closed recirculation system. A VUV spectrometer is connected to the system which monitors the optical transparency of the liquid. This measurement provides one of the pieces of information necessary to model the number of Cherenkov photons which reach the pad plane. A description of the liquid recirculation system and the cleaning procedure for the liquid as well as the spectrometer is presented along with results of their performance. (23 refs).

  8. NUTRIENTS DYNIMIC IN AN AQUAPONIC RECIRCULATING SYSTEM FOR STURGEON AND LETTUCE (LACTUCA SATIVA PRODUCTION

    Directory of Open Access Journals (Sweden)

    LORENA SFETCU

    2013-12-01

    Full Text Available Aquaponics are modern production systems, which integrate the aquaculture technology with hydroponic systems (vegetable production without soil with a goal of fructification of residual nutrients resulted from metabolic activity of fish biomass as high quality vegetable biomass sealable as ecological products. In the present study, as a first step in aquaponic recirculating systems evaluation, the authors aim to compare two types of recirculating systems: classical (hereby noted with RAS and integrated/aquaponic (RAS_A regarding water quality parameters generally, and TAN (total ammonia nitrogen production and transformation, particularly.

  9. Application of the Na+ recirculation theory to ion coupled water transport in low- and high resistance osmoregulatory epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Møbjerg, Nadja; Nielsen, Robert

    2007-01-01

    The theory of Na+ recirculation for isosmotic fluid absorption follows logically from Hertz's convection-diffusion equation applied to the exit of water and solutes from the lateral intercellular space. Experimental evidence is discussed indicating Na+ recirculation based upon the following...

  10. The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio

    NARCIS (Netherlands)

    Martins, C.I.; Pristin, M.G.; Ende, S.S.W.; Eding, E.H.; Verreth, J.A.J.

    2009-01-01

    The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high

  11. An evaluation of a micro programmable logic controller for oxygen monitoring and control in tanks of a recirculating aquaculture system

    Science.gov (United States)

    Control of dissolved gases, especially oxygen is an essential component of recirculating aquaculture systems. The use of pure oxygen in a recirculating aquaculture system creates supersaturated concentrations of dissolved oxygen and can reduce fish production costs by supporting greater fish and fee...

  12. Removal of nitrogen compounds from landfill leachate using reverse osmosis with leachate stabilization in a buffer tank.

    Science.gov (United States)

    Talalaj, Izabela Anna

    2015-01-01

    In this paper, a removal of nitrogen compounds from a landfill leachate during reverse osmosis (RO) was evaluated. The treatment facility consists of a buffer tank and a RO system. The removal rate of N─NH4, [Formula: see text] and [Formula: see text] in the buffer tank reached 14%, 91% and 41%, respectively. The relatively low concentration of organic carbon limits N─NH4 oxidation in the buffer tank. The removal rate for the total organic nitrogen (TON) was 47%. The removal rate in RO was 99% for [Formula: see text], 84.1% for [Formula: see text] and 41% for [Formula: see text]. The accumulation of [Formula: see text] may be the result of a low pH, which before the RO process is reduced to a value of 6.0-6.5. Besides it, the cause for a low removal rate of the [Formula: see text] in the buffer tank and during RO may be free ammonia, which can inhibit the [Formula: see text] oxidation. The removal rates of total inorganic nitrogen and TON in the RO treatment facility were similar being 99% and 98.5%, respectively.

  13. TREATMENT OF LANDFILL LEACHATE BY COUPLING COAGULATION-FLOCCULATION OR OZONATION TO GRANULAR ACTIVATED CARBON ADSORPTION.

    Science.gov (United States)

    Oloibiri, Violet; Ufomba, Innocent; Chys, Michael; Audenaert, Wim; Demeestere, Kristof; Van Hulle, Stijn W H

    2015-01-01

    A major concern for landfilling facilities is the treatment of their leachate. To optimize organic matter removal from this leachate, the combination of two or more techniques is preferred in order to meet stringent effluent standards. In our study, coagulation-flocculation and ozonation are compared as pre- treatment steps for stabilized landfill leachate prior to granular activated carbon (GAC) adsorption. The efficiency of the pre treatment techniques is evaluated using COD and UVA254 measurements. For coagulation- flocculation, different chemicals are compared and optimal dosages are determined. After this, iron (III) chloride is selected for subsequent adsorption studies due to its high percentage of COD and UVA254 removal and good sludge settle-ability. Our finding show that ozonation as a single treatment is effective in reducing COD in landfill leachate by 66% compared to coagulation flocculation (33%). Meanwhile, coagulation performs better in UVA254 reduction than ozonation. Subsequent GAC adsorption of ozonated effluent, coagulated effluent and untreated leachate resulted in 77%, 53% and 8% total COD removal respectively (after 6 bed volumes). The effect of the pre-treatment techniques on GAC adsorption properties is evaluated experimentally and mathematically using Thomas and Yoon-Nelson models. Mathematical modelling of the experimental GAC adsorption data shows that ozonation increases the adsorption capacity and break through time with a factor of 2.5 compared to coagulation-flocculation.

  14.  Distribution and composition of microbial populations in landfill leachate contaminated aquifer (Grindsted, Denmark)

    DEFF Research Database (Denmark)

    Ludvigsen, L; Albrechtsen, HJ; Ringelberg, DB

    1999-01-01

    To investigate whether landfill leachates affected the microbial biomass and/or community composition of the extant microbiota, 37 samples were collected along a 305-m transect of a shallow landfill-leachate polluted aquifer. The samples were analyzed for total numbers of bacteria by use of the a......To investigate whether landfill leachates affected the microbial biomass and/or community composition of the extant microbiota, 37 samples were collected along a 305-m transect of a shallow landfill-leachate polluted aquifer. The samples were analyzed for total numbers of bacteria by use......), and with the greatest concentrations close to the landfill. Methanogens (Archaea) and reducers of sulfate, iron, manganese, and nitrate were all observed in the aquifer. Methanogens were found to be restricted to the most polluted and reduced part of the aquifer at a maximum cell number of 5.4 × 104 cells/g dw....... Populations of sulfate reducers decreased with an increase in horizontal distance from the landfill ranging from a high of 9.0 × 103 cells/g dw to a low of 6 cells/g dw. Iron, manganese, and nitrate reducers were detected throughout the leachate plume all at maximum cell numbers of 106 cells/g dw. Changes...

  15. BIOLEACH: Coupled modeling of leachate and biogas production on solid waste landfills

    Science.gov (United States)

    Rodrigo-Clavero, Maria-Elena; Rodrigo-Ilarri, Javier

    2015-04-01

    One of the most important factors to address when performing the environmental impact assessment of urban solid waste landfills is to evaluate the leachate production. Leachate management (collection and treatment) is also one of the most relevant economical aspects to take into account during the landfill life. Leachate is formed as a solution of biological and chemical components during operational and post-operational phases on urban solid waste landfills as a combination of different processes that involve water gains and looses inside the solid waste mass. Infiltration of external water coming from precipitation is the most important component on this water balance. However, anaerobic waste decomposition and biogas formation processes play also a role on the balance as water-consuming processes. The production of leachate one biogas is therefore a coupled process. Biogas production models usually consider optimal conditions of water content on the solid waste mass. However, real conditions during the operational phase of the landfill may greatly differ from these optimal conditions. In this work, the first results obtained to predict both the leachate and the biogas production as a single coupled phenomenon on real solid waste landfills are shown. The model is applied on a synthetic case considering typical climatological conditions of Mediterranean catchments.

  16. Application of Electrochemical Process in Removal of Heavy Metals from Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Mostafaii Gh.1 PhD,

    2016-08-01

    Full Text Available Aims Municipal landfill leachate contains high concentrations of heavy metals, organics, ammonia. The efficeincy of electrochemically removal of heavy metals from landfill leachate was studied. Materials & Methods The leachate was obtained from Kahrizak landfill in south of Tehran. The experiments were carried out by batch process. The 2liter batch reactor was made of glass. There were eight anodes and cathodes electrodes. The electrodes were placed vertically parallel to each other and they were connected to a digital DC power supply. The pH and conductivity were adjusted to a desirable value using NaOH or H2SO4, and NaCl. All the runs were performed at constant temperature of 25°C. In each run, 1.5liter of the leachate was placed into the electrolytic cell. Samples were extracted every 10min and then filtered through a mixed cellulose acetate membrane (0.42μm. The amount of Lead, Zinc and Nickel removal was measured at pH=7 and in current density of 0.5, 0.75, and 1A. Findings When current density and time reaction increased, removal efficiency of heavy metals such as Lead, Zinc and Nickel increased. At initial pH=7, density 1A and reaction time= 60min, Lead, Nickel and Zinc were removed up to 86, 93 and 95%, respectively. Conclusion Electrochemical process can be proposed as a suitable technique to remove heavy metal from landfill leachate.

  17. High-throughput nucleotide sequence analysis of diverse bacterial communities in leachates of decomposing pig carcasses

    Directory of Open Access Journals (Sweden)

    Seung Hak Yang

    2015-09-01

    Full Text Available The leachate generated by the decomposition of animal carcass has been implicated as an environmental contaminant surrounding the burial site. High-throughput nucleotide sequencing was conducted to investigate the bacterial communities in leachates from the decomposition of pig carcasses. We acquired 51,230 reads from six different samples (1, 2, 3, 4, 6 and 14 week-old carcasses and found that sequences representing the phylum Firmicutes predominated. The diversity of bacterial 16S rRNA gene sequences in the leachate was the highest at 6 weeks, in contrast to those at 2 and 14 weeks. The relative abundance of Firmicutes was reduced, while the proportion of Bacteroidetes and Proteobacteria increased from 3–6 weeks. The representation of phyla was restored after 14 weeks. However, the community structures between the samples taken at 1–2 and 14 weeks differed at the bacterial classification level. The trend in pH was similar to the changes seen in bacterial communities, indicating that the pH of the leachate could be related to the shift in the microbial community. The results indicate that the composition of bacterial communities in leachates of decomposing pig carcasses shifted continuously during the study period and might be influenced by the burial site.

  18. Artemia salina as test organism for assessment of acute toxicity of leachate water from landfills.

    Science.gov (United States)

    Svensson, B M; Mathiasson, L; Mårtensson, L; Bergström, S

    2005-03-01

    Artemia salina has, for the first time, been used as test organism for acute toxicity of leachate water from three landfills (the municipal landfills at Kristianstad, Sweden and Siauliai, Lithuania, and an industrial landfill at Stena fragmenting AB, Halmstad, as well as for leachate from Kristianstad treated in different ways in a pilot plan). Artemia can tolerate the high concentrations of chloride ions found in such waters. Large differences in toxicities were found, the leachate from Siauliai being the most toxic one. To increase the selectivity in the measurements, a fractionation was done by using ion exchange to separate ammonium/ammonia and metal ions from the leachate, and activated carbon adsorbents for organic pollutants. The influence of some metals and phenol compounds on the toxicity was investigated separately. It was found that most of the toxicity emanated from the ammonium/ammonia components in the leachate. However, there was also a significant contribution n from organic pollutants, other than phenol compounds, since separate experiments had in this latter case indicated negligible impact. The concentrations of metals were at a level, shown by separate experiments, where only small contribution to the toxicity could be expected.

  19. REMOVAL OF PHENOL AND SURFACTANT FROM LANDFILL LEACHATE BY COAGULATION-FLOCCULATION PROCESS

    Directory of Open Access Journals (Sweden)

    H. BAKRAOUY

    2016-02-01

    Full Text Available Following the action of rainfall and natural fermentation, the stored waste produces a liquid fraction called leachate. This leachate is rich in organic matter (biodegradable but also refractory and trace elements. There are many techniques of treating the leachate, in particular, biological, physicochemical, membrane processes. The choice of a technique instead of another depends on several parameters including: the age of the leachate, composition... In this work we applied a coagulation-flocculation process to treat intermediate landfill leachate of Rabat city with a combined ferric chloride coagulant and a polymer flocculant. We were inspired by full factorial design, including twenty five experiments, to determine optimal dosages of coagulant and flocculant. We operate at pH 8.4, the best removal efficiencies obtained were 88 % for Turbidity, 98 % for Phenol and 82 % for surfactant. The optimum dosages values determined by this study were 13.2 g∙L-1 of coagulant, 62 mL∙L-1 of flocculant.

  20. Degradation Kinetics of Photoelectrocatalysis on Landfill Leachate Using Codoped TiO2/Ti Photoelectrodes

    Directory of Open Access Journals (Sweden)

    Xiao Zhou

    2015-01-01

    Full Text Available The photoelectrocatalytic (PEC oxidation degradation of landfill leachate rejected by reverse osmosis (RO using a Cu/N codoped TiO2/Ti photoelectrode was kinetically investigated in terms of COD concentration. The key factors affecting the reaction rate of PEC oxidation and the removal efficiency of COD concentration were studied, including the COD concentration of landfill leachate, potential bias applied, pH value of landfill leachate, and the reaction temperature of photoelectrocatalytic reactor. The apparent kinetic model was applied to describe the photoelectrocatalysis reaction. The results showed that the kinetic equation for photoelectrocatalytic oxidation of landfill leachate was fitting well with the experimental data (R2= 0.967~0.998, with average activation energy Ea= 6.35 × 104 J·mol−1. It was found that there was an optimal bias voltage of 20 V and low pH value was favorable for COD removal in landfill leachate. The reaction order of initial COD concentration (1.326 is higher than that of potential bias (1.102 and pH value (0.074, which indicates that the reaction rate can be controlled efficiently through adjusted initial concentration. The experiments demonstrated that potential bias would approach its statured value with increasing potential bias.

  1. In vivo genotoxic effects of industrial waste leachates in mice following oral exposure.

    Science.gov (United States)

    Chandra, Saurabh; Chauhan, Lalit K S; Dhawan, Alok; Murthy, Ramesh C; Gupta, Shrawan K

    2006-06-01

    Contamination of ground water by industrial waste poses potential health hazards for man and his environment. The improper disposal of toxic wastes could allow genotoxic chemicals to percolate into ground waters, and these contaminated ground waters may produce toxicity, including mutation and eventually cancer, in exposed individuals. In the present study, we evaluated the in vivo genotoxic potential of leachates made from three different kinds of industrial waste (tannery waste, metal-based waste, and waste containing dyes and pigments) that are disposed of in areas adjoining human habitation. Three different doses of test leachates were administered by oral gavage for 15 consecutive days to Swiss albino mice; their bone marrow cells were examined for chromosome aberrations (CAs), micronucleated polychromatic erythrocytes (MNPCEs), and DNA damage using the alkaline Comet assay. Exposure to the leachates resulted in significant (P dye-waste leachate produced weaker genotoxic responses. The cytogenetic abnormalities and DNA damage produced by the leachates indicate that humans consuming water contaminated with these materials are at increased risk of developing adverse health consequences.

  2. The attenuation of chemical elements in acidic leachates from coal mineral wastes by soils

    Science.gov (United States)

    Wangen, Lawrence E.; Jones, Marianne M.

    1984-09-01

    The chemical attenuation of acidity and selected elements (aluminum, arsenic, cadmium, cobalt, chromium, copper, fluorine, iron, manganese, nickel, and zinc) in acidic leachates from coal mineral wastes by four natural subsurface soils has been investigated using laboratory column methods Leachate solutions were allowed to percolate through the soils under simulated natural flow conditions, and the elemental concentrations in the influents and effluents were measured periodically Elemental retentions were substantial for all species except managanese, which was eluted in excess from all soils except the most calcareous Two processes appeared to operate in decreasing influent concentrations: (1) precipitation of solid phases caused by increased pH of the leachate as it percolated through the soil, and (2) adsorption of elements onto exchange and sorption sites naturally present in the soil and on iron and aluminum oxide precipitates formed in situ from leachate components because of the increased pH The soil property most important in retention was its alkalinity Thus, carbonaceous soils provide the best control material for acidic leachates from coal mineral wastes. Results show that natural soils can substantially reduce pollutant fluxes to the environment from acidic coal waste dumps and should be considered when selecting waste disposal sites

  3. Utilization of natural zeolite and perlite as landfill liners for in situ leachate treatment in landfills.

    Science.gov (United States)

    Ozel, Ummukulsum; Akdemir, Andaç; Ergun, Osman Nuri

    2012-05-01

    The potential long term environmental impacts of a landfill on groundwater quality depend on its liner material properties. In case synthetic liner materials are damaged during the construction or operation, many of the original chemical and biological constituents are removed by filtration and the adsorptive action of natural liner materials such as natural zeolite, perlite and bentonite minerals. Before leachate treatment, reduction of these constituents is important not only to leachate percolation, but also treatment cost and efficiency. In this study, the pollutant removal efficiency from the leachate was investigated for natural natural zeolite, expanded perlite and bentonite. Experimental studies was performed in boxes made of glass and with 1:10 sloping. Leachate quantity was determined and pH, electrical conductivity (EC), nitrate (NO(3)-N), ammonium-nitrogen (NH(4)-N), phosphate (PO(4)), chemical oxygen demand (COD) and organic matter in leachate samples were measured and the measurement was compared with control process (System 4). The results showed that natural zeolite was effective in removing NO(3), NH(4), PO(4), COD and organic matter with removal efficiencies of 91.20, 95.6, 95.5, 83.4 and 87.8%, respectively. Expanded perlite has high efficiency removing of NO(3), PO(4) and COD 83.2, 91.0 and 62.5%, respectively, but it was unsuccessful in reducing NH(4) (1.5%).

  4. Characterization and pollution potential assessment of Tunceli, Turkey municipal solid waste open dumping site leachates.

    Science.gov (United States)

    Demirbilek, Deniz; Öztüfekçi Önal, Ayten; Demir, Veysel; Uslu, Gulsad; Arslanoglu-Isık, Hilal

    2013-11-01

    Environmental monitoring of leachate quality from an open municipal solid waste dumping site in Tunceli, Turkey was studied in this research. The most commonly examined pollution parameters were determined on a seasonal basis. The annual average 5-day biological oxygen demand (BOD₅) and chemical oxygen demand (COD) values of station points were measured as 70 and 425 mg/L, respectively, and also the average BOD₅/COD ratio (a measure of biodegradability) was calculated as 0.20. The low ratio of biodegradability and slightly alkaline pH values in the leachate samples indicated that the site was characterized by methanogenic conditions. The mean ammonium-nitrogen (NH4 (+)-N) and corresponding phosphate (orthophosphate) values were assayed as 70 and 11 mg/L, respectively. The average solids content in the leachates was measured as 4,681 mg/L (total solids) and 144 mg/L (suspended solids). Very low concentrations of iron, manganese, copper, and zinc in the leachate samples were found and the concentration of cadmium was measured below detection limits. Excessive amount of nutrients and high organic and inorganic pollutant content in the leachates pose serious pollution potential to the environment. Since no drainage system or bio treatment exists in this open dumping site, high permeability of natural soil at the site and in the surrounding area and very fractured and crackled rocks under natural soil are indicators of high groundwater pollution potential in this site.

  5. Toxicity evaluation of leachate of solid waste after biological and photocatalitical treatment

    Directory of Open Access Journals (Sweden)

    Ronaldo Teixeira Pelegrini

    2007-11-01

    Full Text Available The final disposition of urban solid wastes is a practice that still causes serious environmental impacts generating several pollutant subproducts, such as the landfill leachate. The toxicity tests are used in the pollution control with the scope of finding the permissive concentrations of a chemical agent for the development survival of particular alive organisms. This work aims the toxicity evaluation study in leachate samples of in natura solid wastes, after biological treatment through slow filtration and after heterogeneous photocatalitical treatment using TiO2/UV. The ecotoxicological evaluation was executed through accute and chronical toxicity tests using as test organisms: Daphnias similis e Eruca sativa (arugula. On average, the in natura, filtered and photocatalized leachate dilution that kills or inhibits around 50% (EC50 of the Daphnias similes is 6%, 7% and 6% respectively. On average of non observable effect concentration (NOEC of in natura, filtered and photocatalized leachate for arugula is 2%, 1% and 4% respectively; and on average of observable effect concentration (OEC is 5%, 3% and 6% respectively. The toxicity tests showed a great usage in the monitoring and management of waste leachate so that presenting the high toxicity of this effluent for aquatic environment.

  6. Fermentation pre-treatment of landfill leachate for enhanced electron recovery in a microbial electrolysis cell.

    Science.gov (United States)

    Mahmoud, Mohamed; Parameswaran, Prathap; Torres, César I; Rittmann, Bruce E

    2014-01-01

    Pre-fermentation of poorly biodegradable landfill leachate (BOD5/COD ratio of 0.32) was evaluated for enhanced current density (j), Coulombic efficiency (CE), Coulombic recovery (CR), and removal of organics (BOD5 and COD) in a microbial electrolysis cell (MEC). During fermentation, the complex organic matter in the leachate was transformed to simple volatile fatty acids, particularly succinate and acetate in batch tests, but mostly acetate in semi-continuous fermentation. Carbohydrate had the highest degree of fermentation, followed by protein and lipids. j, CE, CR, and BOD5 removal were much greater for an MEC fed with fermented leachate (23 A/m(3) or 16 mA/m(2), 68%, 17.3%, and 83%, respectively) compared to raw leachate (2.5 A/m(3) or 1.7 mA/m(2), 56%, 2.1%, and 5.6%, respectively). All differences support the value of pre-fermentation before an MEC for stabilization of BOD5 and enhanced electron recovery as current when treating a recalcitrant wastewater like landfill leachate.

  7. THE "CHEMICAL OXYGEN DEMAND / TOTAL VOLATILE ACIDS" RATIO AS AN ANAEROBIC TREATABILITY INDICATOR FOR LANDFILL LEACHATES

    Directory of Open Access Journals (Sweden)

    R. C. Contrera

    2015-03-01

    Full Text Available Abstract In some operational circumstances a fast evaluation of landfill leachate anaerobic treatability is necessary, and neither Biochemical Methane Potential nor BOD/COD ratio are fast enough. Looking for a fast indicator, this work evaluated the anaerobic treatability of landfill leachate from São Carlos-SP (Brazil in a pilot scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR. The experiment was conducted at ambient temperature in the landfill area. After the acclimation, at a second stage of operation, the AnSBBR presented efficiency above 70%, in terms of COD removal, utilizing landfill leachate without water dilution, with an inlet COD of about 11,000 mg.L-1, a TVA/COD ratio of approximately 0.6 and reaction time equal to 7 days. To evaluate the landfill leachate biodegradability variation over time, temporal profiles of concentration were performed in the AnSBBR. The landfill leachate anaerobic biodegradability was verified to have a direct and strong relationship to the TVA/COD ratio. For a TVA/CODTotal ratio lower than 0.20, the biodegradability was considered low, for ratios between 0.20 and 0.40 it was considered medium, and above 0.40 it was considered high.

  8. Three-stage aged refuse biofilter for the treatment of landfill leachate

    Institute of Scientific and Technical Information of China (English)

    LI Hongjiang; ZHAO Youcai; SHI Lei; GU Yingying

    2009-01-01

    A field-scale aged refuse (AR) biofilter constructed in Shanghai Refuse Landfill, containing about 7 000 m3 aged refuse inside, was evaluated for its performance in the treatment of landfill leachate. This AR biofilter can be divided into three stages and can manage 50 m3 landfill leachate per day. The physical, chemical, and biological characteristics of AR were analyzed for evaluating the AR biofilter as leachate treatment host. The results revealed that over 87.8%--96.2% of COD and 96.9%--99.4% of ammonia nitrogen were removed by the three-stage AR biofilter when the influent leachate COD and ammonia nitrogen were 5 478-10 842 mg/L and 811-1 582 mg/L, respectively. The final effluent was inodorous and pale yellow with COD and ammonia nitrogen below 267--1,020 mg/L and 6--45 mg/L, respectively. The three-stage AR biofilter had efficient nitrification but relative poor denitrification capacity with a total nitrogen (TN) removal of 58%--73%. The external temperature of AR biofilter did not influence the total ammonia nitrogen removal significantly. It was concluded that the scale-up AR biofilter can work very well and can be a promising technology for the treatment of landfill leachate.

  9. Assessment of groundwater vulnerability to leachate infiltration using electrical resistivity method

    Science.gov (United States)

    Mosuro, G. O.; Omosanya, K. O.; Bayewu, O. O.; Oloruntola, M. O.; Laniyan, T. A.; Atobi, O.; Okubena, M.; Popoola, E.; Adekoya, F.

    2016-02-01

    This aim of this work is to assess the degree of leachate infiltration at a dumpsite in Agbara industrial estate, Southwestern Nigeria using electrical resistivity techniques. Around the dumpsite were 45 vertical electrical sounding (VES) stations and 3 electrical resistivity tomography profiles. Current electrode spread varied from 300 to 600 m for the electrical sounding. Electrode configuration includes Schlumberger and Wenner array for sounding and profiling. The state of leachate contamination was tested using parameters such as aquifer vulnerability index, overburden protective capacity and longitudinal unit conductance (Si) derived from the apparent resistivity values. Four principal geoelectric layers inferred from the VES data include the topsoil, sand, clayey sand, and clay/shale. Resistivity values for these layers vary from 3 to 1688, 203 to 3642 123 to 388, and 67 to 2201 Ω m with corresponding thickness of 0.8-2.4, 2.5-140, 3-26 m and infinity, respectively. The leachate plume occurs at a maximum depth of 10 m on the 2-D inverse models of real electrical resistivity with an average depth of infiltration being 6 m in the study area. The correlation between longitudinal conductance and overburden protective capacity show that aquifers around the dumpsite have poor protective capacity and are vulnerable to leachate contamination. Leachate infiltration is favored by the absence of lithological barriers such as clay which in the study area are either mixed with sand or positioned away from the aquifer.

  10. Impact of landfill leachate on the groundwater quality: A case study in Egypt

    Directory of Open Access Journals (Sweden)

    Magda M. Abd El-Salam

    2015-07-01

    Full Text Available Alexandria Governorate contracted an international company in the field of municipal solid waste management for the collection, transport and disposal of municipal solid waste. Construction and operation of the sanitary landfill sites were also included in the contract for the safe final disposal of solid waste. To evaluate the environmental impacts associated with solid waste landfilling, leachate and groundwater quality near the landfills were analyzed. The results of physico-chemical analyses of leachate confirmed that its characteristics were highly variable with severe contamination of organics, salts and heavy metals. The BOD5/COD ratio (0.69 indicated that the leachate was biodegradable and un-stabilized. It was also found that groundwater in the vicinity of the landfills did not have severe contamination, although certain parameters exceeded the WHO and EPA limits. These parameters included conductivity, total dissolved solids, chlorides, sulfates, Mn and Fe. The results suggested the need for adjusting factors enhancing anaerobic biodegradation that lead to leachate stabilization in addition to continuous monitoring of the groundwater and leachate treatment processes.

  11. Three-stage aged refuse biofilter for the treatment of landfill leachate.

    Science.gov (United States)

    Li, Hongjiang; Zhao, Youcai; Shi, Lei; Gu, Yingying

    2009-01-01

    A field-scale aged refuse (AR) biofilter constructed in Shanghai Refuse Landfill, containing about 7000 m3 aged refuse inside, was evaluated for its performance in the treatment of landfill leachate. This AR biofilter can be divided into three stages and can manage 50 m3 landfill leachate per day. The physical, chemical, and biological characteristics of AR were analyzed for evaluating the AR biofilter as leachate treatment host. The results revealed that over 87.8%-96.2% of COD and 96.9%-99.4% of ammonia nitrogen were removed by the three-stage AR biofilter when the influent leachate COD and ammonia nitrogen concentration were in the range 5478-10842 mg/L and 811-1582 mg/L, respectively. The final effluent was inodorous and pale yellow with COD and ammonia nitrogen below 267-1020 mg/L and 6-45 mg/L, respectively. The three-stage AR biofilter had efficient nitrification but relative poor denitrification capacity with a total nitrogen (TN) removal of 58%-73%. The external temperature of AR biofilter did not influence the total ammonia nitrogen removal significantly. It was concluded that the scale-up AR biofilter can work very well and can be a promising technology for the treatment of landfill leachate.

  12. Pharmaceuticals and other contaminants of emerging concern in landfill leachate of the United States

    Science.gov (United States)

    Kolpin, Dana W.; Masoner, Jason R.; Furlong, Edward T.; Cozzarelli, Isabelle M.; Gray, James L.; Schwab, Eric A.

    2015-01-01

    Landfills are commonly the final respository for a heterogeneous mixture of waste from residential, commercial, and industrial sources. The use of landfills as a means of waste disposal will likely increase as the global population increases and nations develop. Thus, landfills receiving such waste have the potential to produce leachate containing numerous organic chemicals including contaminants of emerging concern (CECs) such as pharmaceuticals, personal care products, and hormones. This leachate is often discharged to pathways that lead directly (e.g. groundwater, streams) or indirectly (e.g. wastewater treament plants) to the environment. Limited research, however, has been conducted regarding the characterisation of landfill leachate for CECs.To provide the first national-scale assessment of CECs in landfill leachate across the United States, fresh leachate samples (i.e. prior to onsite treatment) from 19 landfills in 16 states were collected in 2011 and analysed for 202 CECs [1]. The targeted CECs were selected for analysis because they were expected to be persistent in the environment; are used, excreted, or disposed of in substantial quantities; may have human or environmental health effects; or are potential indicators of environmentally relevant classes of chemicals or source materials.

  13. Formulation of a liquid fertilizer for sorghum (Sorghum bicolor (L.) Moench) using vermicompost leachate.

    Science.gov (United States)

    Gutiérrez-Miceli, Federico Antonio; García-Gómez, Roberto Carlos; Rincón Rosales, Reiner; Abud-Archila, Miguel; María Angela, Oliva Llaven; Cruz, Marcos Joaquín Guillen; Dendooven, Luc

    2008-09-01

    Leachate from vermicomposting contains large amounts of plant nutrients and can be used as liquid fertilizer, but normally diluted to avoid plant damage. The amount of nutrients applied is thus reduced so that an additional fertilizer is required. We investigated how dilution of vermicompost leachate combined with different concentrations of NPK triple 17 fertilizer, and polyoxyethylene tridecyl alcohol as dispersant and polyethylene nonylphenol as adherent to increase efficiency of fertilizer uptake, affected sorghum plant development. The vermicomposting leachate with pH 7.8 and electrolytic conductivity 2.6 dS m(-1), contained 834 mg K(+) l(-1), 247 mg NO(3)(-)l(-1) and 168 mg PO(4)(3-) l(-1), was free of pathogens and resulted in a 65 % germination index. Vermicompost leachate can be used as liquid fertilizer for the cultivation of sorghum without dilution and mixed with 140-170 g l(-1) of NPK triple 17 fertilizer and 2-3 ml(-1) of dispersant and 0-1 ml l(-1) adherent. It was found that vermicompost leachate stimulated plant development, but fertilization with NPK was required for maximum growth.

  14. Evaluation of the Treatment Process of Landfill Leachate Using the Toxicity Assessment Method

    Directory of Open Access Journals (Sweden)

    Aifeng Qiu

    2016-12-01

    Full Text Available Landfill leachate is composed of a complex composition with strong biological toxicity. The combined treatment process of coagulation and sedimentation, anaerobics, electrolysis, and aerobics was set up to treat landfill leachate. This paper explores the effect of different operational parameters of coagulation and sedimentation tanks and electrolytic cells, while investigating the combined process for the removal efficiency of physicochemical indices after processing the landfill leachate. Meanwhile, a battery of toxicity tests with Vibrio fischeri, zebrafish larvae, and embryos were conducted to evaluate acute toxicity and calculated the toxicity reduction efficiency after each treatment process. The combined treatment process resulted in a 100% removal efficiency of Cu, Cd and Zn, and a 93.50% and an 87.44% removal efficiency of Ni and Cr, respectively. The overall removal efficiency of chemical oxygen demand (COD, ammonium nitrogen (NH4+-N, and total nitrogen (TN were 93.57%, 97.46% and 73.60%, respectively. In addition, toxicity test results showed that the acute toxicity of landfill leachate had also been reduced significantly: toxicity units (TU decreased from 84.75 to 12.00 for zebrafish larvae, from 82.64 to 10.55 for zebrafish embryos, and from 3.41 to 0.63 for Vibrio fischeri. The combined treatment process was proved to be an efficient treatment method to remove heavy metals, COD, NH4+-N, and acute bio-toxicity of landfill leachate.

  15. Assessment of groundwater vulnerability to leachate infiltration using electrical resistivity method

    Science.gov (United States)

    Mosuro, G. O.; Omosanya, K. O.; Bayewu, O. O.; Oloruntola, M. O.; Laniyan, T. A.; Atobi, O.; Okubena, M.; Popoola, E.; Adekoya, F.

    2017-09-01

    This aim of this work is to assess the degree of leachate infiltration at a dumpsite in Agbara industrial estate, Southwestern Nigeria using electrical resistivity techniques. Around the dumpsite were 45 vertical electrical sounding (VES) stations and 3 electrical resistivity tomography profiles. Current electrode spread varied from 300 to 600 m for the electrical sounding. Electrode configuration includes Schlumberger and Wenner array for sounding and profiling. The state of leachate contamination was tested using parameters such as aquifer vulnerability index, overburden protective capacity and longitudinal unit conductance (S i) derived from the apparent resistivity values. Four principal geoelectric layers inferred from the VES data include the topsoil, sand, clayey sand, and clay/shale. Resistivity values for these layers vary from 3 to 1688, 203 to 3642 123 to 388, and 67 to 2201 Ω m with corresponding thickness of 0.8-2.4, 2.5-140, 3-26 m and infinity, respectively. The leachate plume occurs at a maximum depth of 10 m on the 2-D inverse models of real electrical resistivity with an average depth of infiltration being 6 m in the study area. The correlation between longitudinal conductance and overburden protective capacity show that aquifers around the dumpsite have poor protective capacity and are vulnerable to leachate contamination. Leachate infiltration is favored by the absence of lithological barriers such as clay which in the study area are either mixed with sand or positioned away from the aquifer.

  16. Co-treatment of landfill leachate and domestic wastewater using a submerged aerobic biofilter.

    Science.gov (United States)

    Ferraz, F M; Povinelli, J; Pozzi, E; Vieira, E M; Trofino, J C

    2014-08-01

    This study used a pilot-scale submerged aerobic biofilter (SAB) to evaluate the co-treatment of domestic wastewater and landfill leachate that was pre-treated by air stripping. The leachate tested volumetric ratios were 0, 2, and 5%. At a hydraulic retention time of 24 h, the SAB was best operated with a volumetric ratio of 2% and removed 98% of the biochemical oxygen demand (BOD), 80% of the chemical oxygen demand (COD) and dissolved organic carbon (DOC), and 90% of the total suspended solids (TSS). A proposed method, which we called the "equivalent in humic acid" (Eq.HA) approach, indicated that the hardly biodegradable organic matter in leachate was removed by partial degradation (71% of DOC Eq.HA removal). Adding leachate at a volumetric ratio of 5%, the concentration of the hardly biodegradable organic matter was decreased primarily as a result of dilution rather than biodegradation, which was confirmed by Fourier transform infrared (FTIR) spectroscopy. The total ammoniacal nitrogen (TAN) was mostly removed (90%) by nitrification, and the SAB performances at the volumetric ratios of 0 and 2% were equal. For the three tested volumetric ratios of leachate (0, 2, and 5%), the concentrations of heavy metals in the treated samples were below the local limits. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. UVR induce optical changes and phosphorous release of lake water and macrophyte leachates in shallow Andean lakes

    Directory of Open Access Journals (Sweden)

    Beatriz MODENUTTI

    2010-02-01

    Full Text Available We carried out laboratory experiments in order to study the effect of ultraviolet radiation (UVR on optical features and phosphorous release of Dissolved Organic Mater (DOM from lake water and macrophyte leachates. Lake water samples were obtained from lakes Escondido and El Trébol, and macrophytes (Potamogeton linguatus and Schoenoplectus californicus from their littoral zones. After UVR exposure, DOM from lake El Trébol seemed to react more quickly than that from Lake Escondido and this seems to be related with the degree of lability or aromaticity in the DOM bulk of each lake. Leachates from both macrophytes showed different absorbance spectra with differences in photochemical transformations after UVR exposure: S. californicus leachates exhibited the highest photodegradation. A significant Soluble Reactive Phosphorus (SRP release was observed in lake water after UVR exposure. Lake El Trébol showed the highest SRP concentrations, suggesting that the release of orthophosphate was favored by low molecular weight DOM. P. linguatus leachates have more dissolved phosphorus content than S. californicus ones and after UVR exposure, P. linguatus leachate did not react to UVR while S. californicus exhibited a decrease in SRP. However both macrophyte leachates showed the higher P release in darkness. The obtained results indicated that macrophyte leachates could contribute significantly to changes in the optical characteristics and in the nutrient content in shallow Andean lakes. An increasing input of P. linguatus leachates would produce DOM of high molecular size and a higher P release than S. californicus.

  18. Measuring organic carbon, nutrients and heavy metals in rivers receiving leachate from controlled and uncontrolled municipal solid waste (MSW) landfills.

    Science.gov (United States)

    Yusof, N; Haraguchi, A; Hassan, M A; Othman, M R; Wakisaka, M; Shirai, Y

    2009-10-01

    Since landfilling is the common method of waste disposal in Malaysia, river water is greatly exposed to the risk of contamination from leachate unless proper leachate management is carried out. In this study, leachates from three different types of landfills, namely active uncontrolled, active controlled and closed controlled, were characterized, and their relationships with river water chemistry were examined monthly for a year. The influence of leachate on river water chemistry from each type of landfill depended on many factors, including the presence of a leachate control mechanism, leachate characteristics, precipitation, surface runoff and the applied treatment. The impact of leachate from an active uncontrolled landfill was the highest, as the organic content, NH(4)(+)-N, Cd and Mn levels appeared high in the river. At the same time, influences of leachate were also observed from both types of controlled landfills in the form of inorganic nitrogen (NH(4)(+)-N, NO(3)(-)-N and NO(2)(-)-N) and heavy metals (Fe, Cr, Ni and Mn). Improper treatment practice led to high levels of some contaminants in the stream near the closed controlled landfill. Meanwhile, the active controlled landfill, which was located near the coastline, was exposed to the risk of contamination resulting from the pyrite oxidation of the surrounding area.

  19. Treatment of leachates of sanitary landfills of urban solid wastes. Tratamiento de lixiviados de vertederos controlados de residuos solidos urbanos

    Energy Technology Data Exchange (ETDEWEB)

    Iza Lopez, J. (Departamento de Ingenieria Quimica y de Medio Ambiente, ETSII, Bilbao (Spain))

    1994-01-01

    The method more used for Urban Solid Wastes is the sanitary landfill. Its management is similar to the industrial process plant. The minimization techniques of wastes are applicated to reduce the environmental impact and to increase the degradation process in order to improve the biogas as alternative energy. This article analyzes the anaerobic digestion, the leachates characterization and treatment of leachates. (Author)

  20. Formation of dimethyldithioarsinic acid in a simulated landfill leachate in relation to hydrosulfide concentration.

    Science.gov (United States)

    An, Jinsung; Kim, Ki-Hyun; Kong, Mihye; Kim, Joo-Ae; Shin, Jeoung Hwa; Ahn, Yun Gyong; Yoon, Hye-On

    2016-02-01

    Dimethyldithioarsinic acid (DMDTA(V)), present in such intense sources as municipal landfill leachate, has drawn a great deal of attention due to its abundant occurrence and different aspect of toxicity. The hydrosulfide (HS(-)) concentration in leachate was studied as a major variable affecting the formation of DMDTA(V). To this end, the HPLC-ICPMS system equipped with the reversed-phase C18 column was used to determine DMDTA(V). Simulated landfill leachates (SLLs) were prepared to cover a mature landfill condition with the addition of sodium sulfate and sulfide at varying concentrations in the presence of dimethylarsinic acid (DMA(V)). The concentration of sodium sulfide added in the SLLs generally exhibited a strong positive correlation with the concentration of DMDTA(V). As such, the formation of DMDTA(V) in the SLLs is demonstrated to be controlled by the interactive relationship between DMA(V) and the HS(-).

  1. Removing heavy metals from Isfahan composting leachate by horizontal subsurface flow constructed wetland.

    Science.gov (United States)

    Bakhshoodeh, Reza; Alavi, Nadali; Soltani Mohammadi, Amir; Ghanavati, Hossein

    2016-06-01

    Composting facility leachate usually contains high concentrations of pollutants including heavy metals that are seriously harmful to the environment and public health. The main purpose of this study was to evaluate heavy metals removal from Isfahan composting facility (ICF) leachate by a horizontal flow constructed wetland (HFCWs) system. Two horizontal systems were constructed, one planted with vetiver and the other without plant as a control. They both operated at a flow rate of 24 L/day with a 5-day hydraulic retention time (HRT). The average removal efficiencies for Cr (53 %), Cd (40 %), Ni (35 %), Pb (30 %), Zn (35 %), and Cu (40 %) in vetiver constructed wetland were significantly higher than those of the control (P Vetiver tolerates the extreme condition in leachate including high total dissolved solids.

  2. Removal of Cu(II) from leachate using natural zeolite as a landfill liner material.

    Science.gov (United States)

    Turan, N Gamze; Ergun, Osman Nuri

    2009-08-15

    All hazardous waste disposal facilities require composite liner systems to act as a barrier against migration of contaminated leachate into the subsurface environment. Removal of copper(II) from leachate was studied using natural zeolite. A serial of laboratory systems on bentonite added natural zeolite was conducted and copper flotation waste was used as hazardous waste. The adsorption capacities and sorption efficiencies were determined. The sorption efficiencies increased with increasing natural zeolite ratio. The pseudo-first-order, the pseudo-second-order, Elovich and the intra-particle diffusion kinetic models were used to describe the kinetic data to estimate the rate constants. The second-order model best described adsorption kinetic data. The results indicated that natural zeolite showed excellent adsorptive characteristics for the removal of copper(II) from leachate and could be used as very good liner materials due to its high uptake capacity and the abundance in availability.

  3. Unusual calcite stromatolites and pisoids from a landfill leachate collection system

    Science.gov (United States)

    Maliva, Robert G.; Missimer, Thomas M.; Leo, Kevin C.; Statom, Richard A.; Dupraz, Christophe; Lynn, Matthew; Dickson, J. A. D.

    2000-10-01

    Low-magnesium calcite stromatolites and pisoids were found to have precipitated within the leachate collection system piping of a Palm Beach County, Florida, landfill. The stromatolites and pisoids formed in an aphotic and anoxic environment that was at times greatly supersaturated with calcite. The stromatolites are composed of branching cylindrical bundles of concentrically laminated radial fibrous crystals. The pisoids consist of concentric layers of radial fibrous and microcrystalline calcite. Bacteria, likely sulfate reducing, appear to have acted as catalysts for calcite crystal nucleation, and thus the formation of the stromatolites and pisoids. The leachate system stromatolites provide a recent example of stromatolites that formed largely by cement precipitation. By acting as catalysts for calcite nucleation, bacteria may cause more rapid cementation than would have occurred under purely abiotic conditions. Rapid calcite precipitation catalyzed by bacteria has interfered with the operation of the Palm Beach County landfill leachate collection by obstructing pipes and may be an unrecognized problem at other landfill sites.

  4. Characteristics of blast furnace slag leachate produced under reduced and oxidized conditions.

    Science.gov (United States)

    Schwab, A P; Hickey, J; Hunter, J; Banks, M K

    2006-01-01

    A laboratory study was conducted to determine the environmental conditions necessary to reproduce leachates observed emerging from blast furnace slag acting as the foundation of highways in northwest Indiana. The leachates in the field are often highly alkaline with a pungent sulfur odor, a distinct green or milky-white in color, and sulfate concentrations exceeding 2,000 mg/L. Slag was equilibrated in the laboratory under both oxidized and anoxic environments and at various slag:water ratios. Constant anoxic conditions were required to produce to green colors in the slag, but high sulfate concentrations were observed only when the suspensions were fully oxidized. Leachate from the study site appears to form as a result of a series of complex chemical reactions including fluctuating oxidized and reduced conditions.

  5. Analysis of Electro-Oxidation Suitability for Landfill Leachate Treatment through an Experimental Study

    Directory of Open Access Journals (Sweden)

    Marco Ragazzi

    2013-09-01

    Full Text Available This paper examines the efficiency of electro-oxidation used as the single pretreatment of landfill leachate. The experiments were performed on three different types of leachate. The results obtained using this electrochemical method results were analyzed after seven days of treatment. The main characteristics of leachate and a diagram of the experimental apparatus are presented. The overall objectives were to contribute to the knowledge of electrochemical treatments for the reduction of COD, BOD5, ammonium, and total suspended solids, and also to examine whether there was any resulting hexavalent chromium in the liquid sample. The yields obtained were considered satisfactory, particularly given the simplicity of this technology. Like all processes used to treat refluent water, the applicability of this technique to a specific industrial refluent needs to be supported by feasibility studies to estimate its effectiveness and optimize the project parameters. This could be a future development of the work.

  6. Lab-scale phytotreatment of old landfill leachate using different energy crops.

    Science.gov (United States)

    Lavagnolo, Maria Cristina; Malagoli, Mario; Garbo, Francesco; Pivato, Alberto; Cossu, Raffaello

    2016-09-01

    Old landfill leachate was treated in lab-scale phytotreatment units using three oleaginous species: sunflower (H), soybean (S) and rapeseed (R). The specific objectives of this study were to identify the effects of plant species combinations with two different soil textures on the reduction of COD, total N (nitrogen) and total P (phosphorous); to identify the correlation between biomass growth and removal efficiency; to assess the potential of oily seeds for the production of biodiesel. The experimental test was carried out using 20L volume pots installed in a greenhouse under different leachate percentages in the feeding and subsequent COD, N and P loads. Significant removal efficiencies were achieved: COD (ɳ>80%), total N (ɳ>70%) and total P (ɳ>95%). Better performances were displayed by the clayey soil. Plants irrigated with leachate, when compared to control units fed only with water and nutrient solution (Hoagland solution), developed a larger plant mass. Sunflower was the best performing species.

  7. Optimisation of sanitary landfill leachate treatment in a sequencing batch reactor.

    Science.gov (United States)

    Spagni, A; Marsili-Libelli, S; Lavagnolo, M C

    2008-01-01

    A bench-scale SBR was operated for almost three years in an attempt to optimise the treatment of leachates generated in old landfill. The results of the first two years were used to design a monitoring and control system based on artificial intelligence concepts. Nitrogen removal was optimized via the nitrite shortcut. Nitrification and N removal were usually higher than 98% and 90%, respectively, whereas COD (of the leachate) removal was approximately 30-40%. The monitoring and control system was demonstrated capable of optimizing process operation, in terms of phase length and external COD addition, to the varying loading conditions. Using the control system developed, a significant improvement of the process was obtained: COD and N load were increased (HRT decrease) and a significant decrease (approximately 34%) of the ratio of COD added to N leachate content was observed.

  8. Enhancing biomethanogenic treatment of fresh incineration leachate using single chambered microbial electrolysis cells.

    Science.gov (United States)

    Gao, Yan; Sun, Dezhi; Dang, Yan; Lei, Yuqing; Ji, Jiayang; Lv, Tingwei; Bian, Rui; Xiao, Zhihui; Yan, Liangming; Holmes, Dawn E

    2017-05-01

    Methanogenic treatment of municipal solid waste (MSW) incineration leachate can be hindered by high concentrations of refractory organic matter and humification of compounds in the leachate. In an attempt to overcome some of these impediments, microbial electrolysis cells (MECs) were incorporated into anaerobic digesters (ADMECs). COD removal efficiencies and methane production were 8.7% and 44.3% higher in ADMECs than in controls, and ADMEC reactors recovered more readily from souring caused by high organic loading rates. The degradation rate of large macromolecules was substantially higher (96% vs 81%) in ADMEC than control effluent, suggesting that MECs stimulated degradation of refractory organic matter and reduced humification. Exoelectrogenic bacteria and microorganisms known to form syntrophic partnerships were enriched in ADMECs. These results show that ADMECs were more effective at treatment of MSW incineration leachate, and should be taken into consideration when designing future treatment facilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. The potential for constructed wetlands to treat alkaline bauxite residue leachate: laboratory investigations.

    Science.gov (United States)

    R, Buckley; T, Curtin; R, Courtney

    2016-07-01

    High alkalinity (pH > 12) of bauxite residue leachates presents challenges for the long-term storage and managements of the residue. Whilst the use of constructed wetlands is gaining in interest for its use in the treatment of alkaline waters, thus far, there is limited evidence of its suitability for treating NaOH dominated bauxite residue leachate. A series of batch trials were conducted to investigate the potential for constructed wetland conferred mechanisms (dilution water quality, contact with CO2, and substrate type) for treating NaOH solutions to levels permissible for discharge (p constructed wetland. Formation of a calcite precipitate was observed in some treatments and further characterisation by XRD and XPS suggested surface coating with Na2CO3. It is therefore suggested that, under suitable conditions, constructed wetland technology can reduce leachate pH to constructed wetland.

  10. Experimental evidence of colloids and nanoparticles presence from 25 waste leachates

    Energy Technology Data Exchange (ETDEWEB)

    Hennebert, Pierre, E-mail: pierre.hennebert@ineris.fr [INERIS – Institut National de l’Environnement Industriel et des Risques, Domaine du Petit Arbois BP33, F-13545 Aix-en-Provence (France); Avellan, Astrid; Yan, Junfang [INERIS – Institut National de l’Environnement Industriel et des Risques, Domaine du Petit Arbois BP33, F-13545 Aix-en-Provence (France); Aguerre-Chariol, Olivier [INERIS, Parc Technologique ALATA, BP No. 2, 60550 Verneuil en Halatte (France)

    2013-09-15

    Highlights: • This work is the first assessment of colloids in waste leachates. • Analytical methods are proposed and discussed. • All the waste have at least one element in colloidal form, and some elements are always colloidal. • Man-made nanoparticles are observed. • It can change the interpretation of leachate elemental concentration. - Abstract: The potential colloids release from a large panel of 25 solid industrial and municipal waste leachates, contaminated soil, contaminated sediments and landfill leachates was studied. Standardized leaching, cascade filtrations and measurement of element concentrations in the microfiltrate (MF) and ultrafiltrate (UF) fraction were used to easily detect colloids potentially released by waste. Precautions against CO{sub 2} capture by alkaline leachates, or bacterial re-growth in leachates from wastes containing organic matter should be taken. Most of the colloidal particles were visible by transmission electron microscopy with energy dispersion spectrometry (TEM–EDS) if their elemental MF concentration is greater than 200 μg l{sup −1}. If the samples are dried during the preparation for microscopy, neoformation of particles can occur from the soluble part of the element. Size distribution analysis measured by photon correlation spectroscopy (PCS) were frequently unvalid, particularly due to polydispersity and/or too low concentrations in the leachates. A low sensitivity device is required, and further improvement is desirable in that field. For some waste leachates, particles had a zeta potential strong enough to remain in suspension. Mn, As, Co, Pb, Sn, Zn had always a colloidal form (MF concentration/UF concentration > 1.5) and total organic carbon (TOC), Fe, P, Ba, Cr, Cu, Ni are partly colloidal for more than half of the samples). Nearly all the micro-pollutants (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Sb, Sn, V and Zn) were found at least once in colloidal form greater than 100 μg l{sup −1}. In particular

  11. Disinfection of water in recirculating aquaculture systems with peracetic acid (PAA)

    Science.gov (United States)

    The disinfection behaviour of peracetic acid (PAA) in recirculating aquaculture systems (RAS) was investigated. Peracetic acid is a strong oxidizing agent found in various concentrations in different products. Three Wofasteril PAA products (E400 (c), Lspecical; AC 150) were tested in vitro for the...

  12. Exhaust Gas Recirculation Control for Large Diesel Engines - Achievable Performance with SISO Design

    DEFF Research Database (Denmark)

    Hansen, Jakob Mahler; Blanke, Mogens; Niemann, Hans Henrik

    2013-01-01

    This paper investigates control possibilities for Exhaust Gas Recirculation (EGR) on large diesel engines. The goal is to reduce the amount of NOx in the exhaust gas by reducing the oxygen concentration available for combustion. Control limitations imposed by the system are assessed using linear...

  13. Investigation of proper modeling of very dense granular flows in the recirculation system of CFBs

    Institute of Scientific and Technical Information of China (English)

    Aristeidis Nikolopoulos; Nikos Nikolopoulos; Nikos Varveris; Sotirios Karellas; Panagiotis Grammelis; Emmanuel Kakaras

    2012-01-01

    The aim of this paper is the development of new models and/or the improvement of existing numerical models,used for simulating granular flow in CFB (circulating fluidized bed) recirculation systems.Most recent models follow the TFM (two-fluid model) methodology,but they cannot effectively simulate the inter-particle friction forces in the recirculation system,because the respective stress tensor does not incorporate compressibility of flow due to change of effective particle density.As a consequence,the induced normal and shear stresses are not modeled appropriately during the flow of the granular phase in the CFB recirculation system.The failure of conventional models,such as that of von Mises/Coulomb,is mainly caused by false approximation of the yield criterion which is not applicable to the CFB recirculation system.The present work adopts an alternative yield function,used for the first time in TFM Eulerian modeling.The proposed model is based on the Pitman-Schaeffer-Gray-Stiles yield criterion.Both the temporal deformation of the solid granular phase and the repose angle that the granular phase forms are more accurately simulated by this model.The numerical results of the proposed model agree well with experimental data,implying that frictional forces are efficiently simulated by the new model.

  14. CCR7 Controls Thymus Recirculation, but Not Production and Emigration, of Foxp3(+) T Cells.

    Science.gov (United States)

    Cowan, Jennifer E; McCarthy, Nicholas I; Anderson, Graham

    2016-02-09

    Current models of Foxp3(+) regulatory T cell (Treg) development involve CCR7-mediated migration of thymocytes into the thymus medulla to enable essential interactions with medullary epithelium. However, increased Foxp3(+) thymic Treg numbers in Ccr7(-/-) mice challenge this view, and the role of CCR7 in Treg development, emigration, and/or recirculation is unknown. Here, we have examined CCR7 and Rag2pGFP levels during Treg development and generated Rag2pGFPCcr7(-/-) mice to study its impact on the intrathymic Treg pool. We reveal surprising developmental heterogeneity in thymocytes described as Treg precursors, showing that they contain recirculating CCR6(+)CCR7(-)Rag2pGFP(-) T cells. Although CCR7 defines bona fide Rag2GFP(+) Treg precursors, it is not required for Treg production and emigration. Rather, we show that lack of CCR7 renders the thymus more receptive to Treg thymus homing. Our study reveals a role for CCR7 in limiting Treg recirculation back to the thymus and enables separation of the mechanisms controlling Treg production and thymic recirculation.

  15. The impact of building recirculation rates on secondary organic aerosols generated by indoor chemistry

    DEFF Research Database (Denmark)

    Zuraimi, M.S.; Weschler, Charles J.; Tham, K.W.

    2007-01-01

    reactions between indoor limonene and ozone. The experiments were conducted in a large environmental chamber using four recirculation rates (11, 14, 19 and 24 air change per hour (ACH)) and a constant outdoor air exchange rate (I ACH) as well as constant emission rates for limonene and ozone...

  16. HRT and nutrients affect bacterial communities grown on recirculation aquaculture system effluents

    NARCIS (Netherlands)

    Schneider, O.; Chabrillon-Popelka, M.; Smidt, H.; Haenen, O.L.M.; Sereti, V.; Eding, E.H.; Verreth, J.A.J.

    2007-01-01

    In a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. Because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. B

  17. Control-Oriented Model of Molar Scavenge Oxygen Fraction for Exhaust Recirculation in Large Diesel Engines

    DEFF Research Database (Denmark)

    Nielsen, Kræn Vodder; Blanke, Mogens; Eriksson, Lars;

    2016-01-01

    Exhaust gas recirculation (EGR) systems have been introduced to large marine engines in order to reduce NOx formation. Adequate modelling for control design is one of the bottlenecks to design EGR control that also meets emission requirements during transient loading conditions. This paper...

  18. Optimization of blue mussel (Mytilus edulis) seed culture using recirculation aquaculture systems

    NARCIS (Netherlands)

    Blanco Garcia, A.; Kamermans, P.

    2015-01-01

    By introducing recirculation aquaculture systems (RAS) in the nursery phase of the blue mussel (Mytilus edulis) (17–18 mm), we aimed at a similar growth and survival and a similar water quality compared to the commonly used flow-through systems (FTS). To calculate water flow and size of the biofilte

  19. Recirculating linacs for a neutrino factory--Arc optics design and optimization

    CERN Document Server

    Bogacz, S A

    2001-01-01

    A conceptual lattice design for a muon accelerator based on recirculating linacs (Nucl. Instr. and Meth. A 472 (2001) 499, these proceedings) is presented here. The challenge of accelerating and transporting a large phase space of short-lived muons is answered here by presenting a proof-of-principle lattice design for a recirculating linac accelerator. It is the centerpiece of a chain of accelerators consisting of a 3 GeV linac and two consecutive recirculating linear accelerators, which facilitates acceleration starting after ionization cooling at 190 MeV/c and proceeding to 50 GeV. Beam transport issues for large-momentum-spread beams are accommodated by appropriate lattice design choices. The resulting arc optics is further optimized with a sextupole correction to suppress chromatic effects contributing to the emittance dilution. The presented proof-of-principle design of the arc optics with horizontal separation of multi-pass beams can be extended to all passes in both recirculating linacs.

  20. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg

    2012-01-01

    The aim of the present work was to simulate water treatment practices with hydrogen peroxide (HP) in recirculating aquaculture systems (RAS). Six identical 1,700-L pilot-scale RAS were divided into two experimental groups based on daily feed allocation and operated under constant conditions...

  1. Evaluation of a rainbow trout (Oncorhynchus mikyss culture water recirculating system

    Directory of Open Access Journals (Sweden)

    Iván Sánchez O.

    2014-09-01

    Full Text Available Objective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tube pieces and a natural degassing system; the sedimentation unit effluent was pumped up to a reservoir tank using a 2 HP centrifugal pump after being subject to gravity through the biofilter and to be then distributed to the 12 culture units to which a constant amount of air from a blower was injected. Results. The water treatment system removed 31% of total suspended solids, 9.5% of total ammonia nitrogen, and increased dissolved oxygen to the final effluent in 6.5%. An increase of 305% in biomass was calculated during 75 days, the mortality percentage registered throughout the study period was 4.9%. Conclusions. The water treatment system maintained the physicochemical water quality parameters within the values recommended for the species. The increase in weight and size, food conversion, mortality and biomass production reported normal values for rainbow trout fish culture in recirculating systems.

  2. Suction-recirculation device for stabilizing particle flows within a solar powered solid particle receiver

    Science.gov (United States)

    Kolb, Gregory J [Albuquerque, NM

    2012-02-07

    A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained. Suction-recirculation velocities in the range of 1-5 m/s are sufficient to stabilize the particle curtain against external wind speeds in excess of 10 m/s.

  3. Improving sustainability of striped catfish (Pangasianodon hypophthalmus) farming in the Mekong Delta, Vietnam through recirculation technology

    NARCIS (Netherlands)

    Nguyen, Nhut

    2016-01-01

    The aim of this thesis was to document improvements in sustainability indicators of striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878) production through the application of recirculation and waste treatment techniques. To be able to document improvements in sustainability, in each system s

  4. Adoption of Recirculating Aquaculture Systems in Pangasius Farms: A Choice Experiment

    NARCIS (Netherlands)

    Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.T.; Bosma, R.H.; Oude Lansink, A.G.J.M.

    2015-01-01

    A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to

  5. Adoption of Recirculating Aquaculture Systems in Large Pangasius Farms: A Choice Experiment

    NARCIS (Netherlands)

    Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.C.; Verreth, J.A.J.; Bosma, R.H.; Oude Lansink, A.G.J.M.

    2016-01-01

    A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to

  6. Removal of Nutrients from Septic Effluent with Re-circulated Hybrid Tidal Flow Constructed Wetland

    Science.gov (United States)

    Lihua Cui; Jigkun Feng; Ying Ouyang; Peiwen. Deng

    2012-01-01

    Hybrid tidal flow constructed wetland (CW) with recirculation is an improved biological and engineering technique for removal of excess nutrients and certain pollutants from wastewater. This study investigated the removal efficiency of total phosphorus (TP), ammonia-nitrogen (NH3-N), and total nitrogen (TN) from septic tank effluent with the hybrid tidal flow CW system...

  7. Multi-point optimization of recirculation flow type casing treatment in centrifugal compressors

    Science.gov (United States)

    Tun, Min Thaw; Sakaguchi, Daisaku

    2016-06-01

    High-pressure ratio and wide operating range are highly required for a turbocharger in diesel engines. A recirculation flow type casing treatment is effective for flow range enhancement of centrifugal compressors. Two ring grooves on a suction pipe and a shroud casing wall are connected by means of an annular passage and stable recirculation flow is formed at small flow rates from the downstream groove toward the upstream groove through the annular bypass. The shape of baseline recirculation flow type casing is modified and optimized by using a multi-point optimization code with a metamodel assisted evolutionary algorithm embedding a commercial CFD code CFX from ANSYS. The numerical optimization results give the optimized design of casing with improving adiabatic efficiency in wide operating flow rate range. Sensitivity analysis of design parameters as a function of efficiency has been performed. It is found that the optimized casing design provides optimized recirculation flow rate, in which an increment of entropy rise is minimized at grooves and passages of the rotating impeller.

  8. Access recirculation in a native fistula in spite of a seemingly adequate access flow

    NARCIS (Netherlands)

    Haas, Mark; Spargo, Benjamin H.; Wit, Ernst-Jan C.; Meehan, Shane M.

    2000-01-01

    True access recirculation (AR) measured by ultrasound dilution technique is usually absent in well-working shunts. It occurs with low access flows (Qa). High access flow rates are assumed to prevent AR. Two major exceptions to these rules are known: presence of intra-access strictures and inadverten

  9. Building America Case Study: Control Retrofits for Multifamily Domestic Hot Water Recirculation Systems, Brooklyn, New York

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperature modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7 percent after implementing the demand control technique, 2 percent after implementing temperature modulation, and 15 percent after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8 percent, 1 percent, and 14 percent for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.

  10. Nitrate removal effectiveness of fluidized sulfur-based autotrophic denitrification biofilters for recirculating aquaculture systems

    Science.gov (United States)

    There is a need to develop practical methods to reduce nitrate -nitrogen loads from recirculating aqua-culture systems to facilitate increased food protein production simultaneously with attainment of water quality goals. The most common wastewater denitrification treatment systems utilize methanol-...

  11. Water cortisol and testosterone in Nile tilapia (Oreochromis niloticus) recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical

  12. Researchers evaluate low-energy recirculating system for inland production of marine finfish juveniles

    Science.gov (United States)

    The low-energy recirculating aquaculture system consists of nine separate modules which utilize the double drain fish culture tank paired to a moving bed biofilter. The nine fiberglass tanks are five feet in diameter and normal water depth is about three feet for a total tank volume of approximately...

  13. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    Science.gov (United States)

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  14. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    Science.gov (United States)

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  15. Performance evaluation of Large Eddy Simulation for recirculating and swirling flows

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Cheol Hong; Lee, Chang Eon [Inha University, Incheon (Korea, Republic of)

    2006-04-15

    The objective of this study is to evaluate the efficiency and the prediction accuracy of developed Large Eddy Simulation (LES) program for complex turbulent flows, such as recirculating and swirling flows. To save the computational cost, a Beowulf cluster system consisting 16 processors was constructed. The flows in backward-facing step and dump combustor were examined as representative recirculating and swirling flows. Firstly, a Direct Numerical Simulation (DNS) for laminar backward-facing step flows was previously conducted to validate the overall performance of program. Then LES was carried out for turbulent backward-facing step flows. The results of laminar flow showed a qualitative and quantitative agreement between simulations and experiments. The simulations of the turbulent flow also showed reasonable results. Secondly, LES results for non-swirling and swirling flows in a dump combustor were compared with the results of Reynolds-Averaged Navier-Stokes (RANS) using standard {kappa}-{epsilon} model. The results show that LES has a better performance in predicting the mean axial and azimuthal velocities, Corner Recirculation Zone (CRZ) and Center Toroidal Recirculation Zone (CTRZ) than those of RANS. Finally, it was examined the capability of LES for the description of unsteady phenomena.

  16. The benefits of powdered activated carbon recirculation for micropollutant removal in advanced wastewater treatment.

    Science.gov (United States)

    Meinel, F; Zietzschmann, F; Ruhl, A S; Sperlich, A; Jekel, M

    2016-03-15

    PAC adsorption is a widespread option for the removal of organic micropollutants (OMP) from secondary effluent. For an optimal exploitation of the adsorption capacity, PAC recirculation is nowadays a common practice, although the mechanistic interrelations of the complex recirculation process are not fully resolved. In this work, extensive multi-stage batch adsorption testing with repeated PAC and coagulant dosage was performed to evaluate the continuous-flow recirculation system. Partly loaded PAC showed a distinct amount of remaining capacity, as OMP and DOC removals considerably increased with each additional adsorption stage. At a low PAC dose of 10 mg PAC L(-1), removals of benzotriazole and carbamazepine were shown to rise from 80% in the 11th stage at 30 min adsorption time per stage. At a high PAC dose of 30 mg PAC L(-1), OMP and DOC removals were significantly higher and reached 98% (for benzotriazole and carbamazepine) after 11 stages. Coagulant dosage showed no influence on OMP removal, whereas a major part of DOC removal can be attributed to coagulation. Multi-stage adsorption is particularly beneficial for small PAC doses and significant PAC savings are feasible. A new model approach for predicting multi-stage OMP adsorption on the basis of a single-stage adsorption experiment was developed. It proved to predict OMP removals and PAC loadings accurately and thus contributes towards understanding the PAC recirculation process.

  17. Mixing and Recirculation Characteristics of A double COncentric Burner with Bluff—Body

    Institute of Scientific and Technical Information of China (English)

    H.K.Ma; C.H.Chiou; 等

    1993-01-01

    The concentric bluff-body jet burner is widely used in industrial combustion systems.This kind of burner often generates a considerably complex recirculation zone behind the bluff body.As a result,the fuel often remains in the recirculation zone,achieving stability of flame.This study investigates,by means of experiments,the variations of the aerodynamics as the fluid is injected into a combustion chamber through a doble concentric burner with a bluff-body.The observation and measurement of the aerodynamics in our experiment are conducted under a cold flow.The controlled parameters in our experiment are:variations in the blockage ratio of the center bluff body,the cone angle of the bluff body,and the velocity ratio(Us/Up) of the secondary jet and primary jet;the injection of helium bubbles into the primary and secondary jets to observe the recirculation zone behind the bluff body;using Tufts for obseving the characteristics of corner recirculation zone in a combustion chamber,measuring the average velocity of each point within the aerodynamics by the 5-hole pitot tube;measuring the distribution of static pressure of the combustion chamber walls with a static pressure tap.

  18. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.

    2015-01-01

    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to examin

  19. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.

    2015-01-01

    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to

  20. Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation

    Science.gov (United States)

    Airlifts simplify recirculating aquaculture systems and can potentially reduce capital costs and minimize maintenance issues. Airlifts have the ability to move and aerate water as well as degass the water of any carbon dioxide. This study evaluated the oxygen transfer and carbon dioxide removal abil...

  1. Geosmin causes off-flavour in arctic charr in recirculating aquaculture systems

    Science.gov (United States)

    The “earthy” and “muddy” off-flavors in pond-reared fish are due to the presence of geosmin or 2-methylisoborneol (MIB) in the flesh of the fish. Similar off-flavors have been reported in fish raised in recirculating aquaculture systems (RAS); however, little information is available regarding the ...

  2. Water cortisol and testosterone in Nile tilapia (Oreochromis niloticus) recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical l

  3. Solids removal from a coldwater recirculating system - comparison of swirl separator and radial-flow settlers

    Science.gov (United States)

    Solids removal across two settling devices, i.e., a swirl separator and a radial-flow settler, and across a microscreen drum filter was evaluated in a fully recirculating system containing a single 150 m3 'Cornell-type' dual-drain tank during the production of food-size Arctic char and rainbow trout...

  4. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Science.gov (United States)

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  5. Anaerobic Digestion of the Organic Fraction of Municipal Solid Waste With Recirculation of Process Water

    DEFF Research Database (Denmark)

    Hartmann, H.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2001-01-01

    A new concept of a wet anaerobic digestion treatment of the organic fraction of municipal solid waste (OFMSW) is investigated. Once the waste is diluted with water, the entire liquid fraction of the effluent is recirculated and used as process water for dilution of the waste. This enables a well...

  6. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2013-06-01

    Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.

  7. Pilot-scale study of powdered activated carbon recirculation for micropollutant removal.

    Science.gov (United States)

    Meinel, F; Sperlich, A; Jekel, M

    Adsorption onto powdered activated carbon (PAC) is a promising technique for the removal of organic micropollutants (OMPs) from treated wastewater. To enhance the adsorption efficiency, PAC is recycled back into the adsorption stage. This technique was examined in pilot scale in comparison to a reference without recirculation. Coagulation with Fe(3+) was carried out simultaneously to adsorption. Extensive OMP measurements showed that recirculation significantly increased OMP eliminations. Thus, significant PAC savings were feasible. The PAC concentration in the contact reactor proved to be an important operating parameter that can be surrogated by the easily measurable total suspended solids (TSS) concentration. OMP eliminations increased with increasing TSS concentrations. At 20 mg PAC L(-1) and 2.8 g TSS L(-1) in the contact reactor, well-adsorbable carbamazepine was eliminated by 97%, moderately adsorbable diclofenac was eliminated by 92% and poorly-adsorbable acesulfame was eliminated by 54% in comparison to 49%, 35% and 18%, respectively, without recirculation. The recirculation system represents an efficient technique, as the PAC's adsorption capacity is practically completely used. Small PAC dosages yield high OMP eliminations. Poorly-adsorbable gabapentin was eliminated to an unexpectedly high degree. A laboratory-scale biomass inhibition study showed that aerobic biodegradation removed gabapentin in addition to adsorption.

  8. Investigation of landfill leachate toxic potency: An integrated approach with the use of stress indices in tissues of mussels

    Energy Technology Data Exchange (ETDEWEB)

    Tsarpali, Vasiliki [Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, 26500 Patras (Greece); Dailianis, Stefanos, E-mail: sdailianis@upatras.gr [Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, 26500 Patras (Greece)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Leachate induces mortality of mussels and their cell death at very low doses. Black-Right-Pointing-Pointer Prepathological alterations occur in tissues of leachate-exposed mussels. Black-Right-Pointing-Pointer Alterations of stress indices reveal neurotoxic and genotoxic potency of leachate. Black-Right-Pointing-Pointer Leachate could induce oxidative damage in tissues of leachate-exposed mussels. - Abstract: The present study investigates the harmful impacts of landfill leachate release and/or disposal into the marine environment, as well as its ability to induce lethal and pre-pathological alterations in marine organisms, such as the mussel Mytilus galloprovincialis. In specific, mortality test (96 h), performed first in order to estimate leachate lethal endpoints, showed increased levels of mussel mortality after exposure to leachate higher than 0.5%, v/v (96 h LC{sub 50} = 0.526%, v/v), while the exposure to 0.01 and 0.1% (v/v) of leachate showed negligible levels of mortality (96 h LC{sub 10} = 0.167%, v/v). Furthermore, the estimation of lysosomal membrane integrity in hemocytes of exposed mussels (Neutral Red Retention Time assay) showed increased levels of lysosomal destabilization in cells of mussels exposed to sub-lethal concentrations of leachate (0.01, 0.1 and 0.5%, v/v) for 4 days. In order to exclude parameters, such as mussel mortality and cell death, which could interfere with the obtained results, leachate at final concentrations of 0.01 and 0.1% (v/v) were finally used for the estimation of a battery of stress indices in target tissues of mussels, such as hemolymph, gills and digestive gland. According to the results, leachate-exposed mussels showed a significant inhibition of acetylcholinesterase activity, increased levels of nuclear abnormalities, as well as increased levels of metallothionein, superoxide anion and lipid peroxides (in terms of malondialdehyde equivalents) in each tissue tested. The

  9. [Litter decomposition of dominant plantations in Guangxi and its effects on leachate quality].

    Science.gov (United States)

    Yang, Gai-Ren; Zhang, Xiu-Qing; Cai, De-Suo; Shi, Xian-Hui; Zhang, Hua; Huang, Cheng-Biao

    2012-01-01

    To understand the decomposition characteristics of the litters in different forest plantations and the effects of released substances during litter decomposition on the leachate quality, litter samples (leaf, shoot, and cortices) were collected from five forest plantations (1 year-old Eucalyptus urophylla x E. grandis, EU1; 4 year-old Eucalyptus urophylla x E. grandis, EU4; 7 year-old Acacia mangium x A. auriculaef, AM; 13 year-old Pinus massoniana Lamb, PL; and mixed broad-leaved softwood, BL), and incubated at 28 degrees C, using water leached for 255 days. In the first 105 days, the litter leachates of EU1 and EU4 had significantly higher coloration and N and P contents and lower pH than those of AM, PL, and BL. On the 255th day, the cumulative chemical oxygen demand (COD) in the leaf litters leachates of EU1 and EU4 was 193.9 and 212.8 g x kg(-1), being 4.2, 4.0, and 4.3 times and 5.3, 4.4, and 4.7 times higher than that of AM, PL, and BL, respectively. The mass loss rate and the N and P leaching rate of the leaf litter of EU1 were significantly higher than those of AM, PL, and BL. The mass loss rate of cortices of EU1 was significantly higher than that of PL. No significant difference was observed for the leaching rate of the shoot litters between AM, PL, and BL. Among the litter samples, leaf litter was easiest to be decomposed, while shoot litter was most difficult to be decomposed. The pH value of the litter leachates of Eucalyptus plantations was significantly negatively correlated with leachate chroma and COD, and the COD had significant positive correlations with the concentrations of total N and P in the leachates.

  10. Recovery of molybdenum, nickel and cobalt by precipitation from the acidic leachate of a mineral sludge.

    Science.gov (United States)

    Vemic, M; Bordas, F; Comte, S; Guibaud, G; Lens, P N L; van Hullebusch, E D

    2016-09-01

    The objective of this study was to investigate the recovery potential of molybdenum (Mo), nickel (Ni) and cobalt (Co) from synthetic and real acidic leachate of a mineral sludge from a metal recycling plant by sulfide precipitation. The operational parameters (metal sulfide (M/S) ratio 0.1-1, agitation speed 0-100 rpm, contact time 15-120 min and pH 1-5) were optimized in batch conditions on synthetic metal leachate (0.5 M HNO3, Mo = 101.6 mg L(-1), Ni = 70.8 mg L(-1), Co = 27.1 mg L(-1)) with a 0.1 M Na2S solution. Additionally, recovery of the target metals was theoretically simulated with a chemical equilibrium model (Visual MINTEQ 3.0). The optimized Na2S precipitation of metals from the synthetic leachate resulted in the potential selective recovery of Mo at pH 1 (98% by modeling, 95% experimental), after simultaneous precipitation of Ni and Co as sulfide at pH 4 (100% by modeling, 98% experimental). Metal precipitation from the real leachate (18 M H2SO4, Mo = 10,160 mg L(-1), Ni = 7,080 mg L(-1), Co = 2,710 mg L(-1)) was performed with 1 M Na2S, and resulted in a maximal Mo recovery at pH 2 (50%), while maximal recoveries of Ni and Co were observed at pH 4 (56% and 60%, respectively). Real leachate gave a lower metals recovery efficiency compared with synthetic leachate, which can be attributed to changes in the pH, nature of leachant, co-precipitation of Zn and competition for S(2-) ions.

  11. The Study of LeachateTreatment by Using Three Advanced Oxidation Process Based Wet air Oxidation

    Directory of Open Access Journals (Sweden)

    Behroz Karimi

    2013-01-01

    Full Text Available Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300[degree sign] as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter.

  12. Plants' use of leachate derived from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Revel, J.C.; Morard, P.; Bailly, J.R.; Labbe, H.; Berthout, C.; Kaemmerer, M.

    1999-08-01

    Leachate was collected from a watertight pit at a landfill center dealing mainly with household refuse and plant waste. This effluent was characterized by a moderate organic matter content, a pH slightly higher than neutral and strong electrical conductivity. This latter was due to the presence of chlorides, Na, K, and ammonium. The organic content could be divided into two fractions: Fraction A consisting of large molecules and Fraction B of smaller, more acidic molecules. The presence of phenols could be identified in the leachate as a whole. A biological treatment of this leachate, involving methanization followed by aerated lagooning, was set up on the site: this led to a reduction of nearly 60% in the organic content and almost total elimination of the ammonium. This treatment was not however sufficient to allow direct evacuation of the resulting effluent into the surface ground water. As heavy metals were absent from this effluent, the leachates from this landfill site could possibly be envisaged in the fertilization of soil-grown crops or for furrow irrigation-fertilization of tree plantations. The effect of irrigating soil-grown plants with a solution of leachate was examined using pots of ryegrass (Lolium sp.). Application of solutions containing dilutions of 1 to 400 mL L{sup {minus}1} of this effluent had a highly favorable effect on plant growth. Toxicity phenomena were apparent above this concentration. The optimum effect on ryegrass growth, under the conditions of this trial, was obtained by watering each pot with 30 mL of a solution containing 400 mL L{sup {minus}1} of leachate, every 2 d. This solution improved water and N nutrition in these plants.

  13. The study of leachate treatment by using three advanced oxidation process based wet air oxidation.

    Science.gov (United States)

    Karimi, Behroz; Ehrampoush, Mohammad Hassan; Ebrahimi, Asghar; Mokhtari, Mehdi

    2013-01-02

    Wet air oxidation is regarded as appropriate options for wastewater treatment with average organic compounds. The general purpose of this research is to determine the efficiency of three wet air oxidation methods, wet oxidation with hydrogen peroxide and absorption with activated carbon in removing organic matter and nitrogenous compounds from Isfahan's urban leachate. A leachate sample with the volume of 1.5 liters entered into a steel reactor with the volume of three liters and was put under a 10-bar pressure, at temperatures of 100, 200, and 300° as well as three retention times of 30, 60, and 90 minutes. The sample was placed at 18 stages of leachate storage ponds in Isfahan Compost Plant with the volume of 20 liters, using three WPO, WAO methods and a combination of WAO/GAC for leachate pre-treatment. Thirty percent of pure oxygen and hydrogen peroxide were applied as oxidation agents. The COD removal efficiency in WAO method is 7.8-33.3%, in BOD is 14.7-50.6%, the maximum removal percentage (efficiency) for NH4-N is 53.3% and for NO3-N is 56.4-73.9%. The removal efficiency of COD and BOD5 is 4.6%-34 and 24%-50 respectively in WPO method. Adding GAC to the reactor, the removal efficiency of all parameters was improved. The maximum removal efficiency was increased 48% for COD, 31%-43.6 for BOD5 by a combinational method, and the ratio of BOD5/COD was also increased to 90%. In this paper, WAO and WPO process was used for Leachate pre-treatment and WAO/GAC combinational process was applied for improving the organic matter removal and leachate treatment; it was also determined that the recent process is much more efficient in removing resistant organic matter.

  14. Elements in cottonwood trees as an indicator of ground water contaminated by landfill leachate

    Science.gov (United States)

    Erdman, James A.; Christenson, Scott

    2000-01-01

    Ground water at the Norman Landfill Research Site is contaminated by a leachate plume emanating from a closed, unlined landfill formerly operated by the city of Norman, Oklahoma, Ground water contaminated by the leachate plume is known to be elevated in the concentration of many, organic and inorganic constituents. Specific conductance, alkalinity, chloride, dissolved organic carbon, boron, sodium, strontium, and deuterium in ground water are considered to be indicators of the leachate plume at this site. Leaf samples of broad-leafed cottonwood, Populus deltoides, were collected from 57 sites around the closed landfill. Cottonwood, a phreatophyte or “well plant,” functions as a & surrogate well and serves as a ground water quality sampler. The leaf samples were combusted to ash and analyzed by instrumental neutron activation for 35 elements and by prompt-gamma instrumental neutron activation, for boron. A monitoring well was located within a few meters of a sampled cottonwood tree at 15 of the 57 sites, and ground water samples were collected from these monitoring wells simultaneously with a leaf sample. The chemical analyses of the ground water and leaf samples from these 15 sites indicated that boron, bromine, sodium, and strontium concentrations in leaves were significantly correlated with leachate indicator constituents in ground water. A point-plot map of selected percentiles indicated high concentrations of boron, bromine, and sodium in leaf ash from sites downgradient of the most recent landfill and from older landfills nearby. Data from leaf analysis greatly extended the known areal extent of the leachate plume previously determined from a network of monitoring wells and geophysical surveys. This phytosgeochemical study provided a cost-effective method for assessing the extent of a leachate plume from an old landfill. Such a method may be useful as a preliminary sampling tool to guide the design of hydrogeochemical and geophysical studies.

  15. Relationships between antibiotics and antibiotic resistance gene levels in municipal solid waste leachates in Shanghai, China.

    Science.gov (United States)

    Wu, Dong; Huang, Zhiting; Yang, Kai; Graham, David; Xie, Bing

    2015-04-01

    Many studies have quantified antibiotics and antibiotic resistance gene (ARG) levels in soils, surface waters, and waste treatment plants (WTPs). However, similar work on municipal solid waste (MSW) landfill leachates is limited, which is concerning because antibiotics disposal is often in the MSW stream. Here we quantified 20 sulfonamide (SA), quinolone (FQ), tetracycline (TC), macrolide (ML), and chloramphenicol (CP) antibiotics, and six ARGs (sul1, sul2, tetQ, tetM, ermB, and mefA) in MSW leachates from two Shanghai transfer stations (TS; sites Hulin (HL) and Xupu (XP)) and one landfill reservoir (LR) in April and July 2014. Antibiotic levels were higher in TS than LR leachates (985 ± 1965 ng/L vs 345 ± 932 ng/L, n = 40), which was because of very high levels in the HL leachates (averaging at 1676 ± 5175 ng/L, n = 40). The mean MLs (3561 ± 8377 ng/L, n = 12), FQs (975 ± 1608 ng/L, n = 24), and SAs (402 ± 704 ng/L, n = 42) classes of antibiotics were highest across all samples. ARGs were detected in all leachate samples with normalized sul2 and ermB levels being especially elevated (-1.37 ± 1.2 and -1.76 ± 1.6 log (copies/16S-rDNA), respectively). However, ARG abundances did not correlate with detected antibiotic levels, except for tetW and tetQ with TC levels (r = 0.88 and 0.81, respectively). In contrast, most measured ARGs did significantly correlate with heavy metal levels (p antibiotics can prevail in MSW leachates and landfills may be an underappreciated as a source of antibiotics and ARGs to the environment.

  16. Comparisons of Three Advanced Oxidation Processes in Organic Matter Removal from Esfahan Composting Factory Leachate

    Directory of Open Access Journals (Sweden)

    karimi B.

    2011-06-01

    Full Text Available Backgrounds and Objectives: Wet air oxidation (WAO is one of the advanced oxidation process which is mostly used to reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substance and solid waste leachate.The objective of this paper is comparisons of three advance oxidation in organic matter removal in different conditions from Esfahan composing factory leachateMaterial and Methods: The experiment was carried out by adding 1.5 Lit pretreated leachate sample to 3Lit autoclave reactor and adding 10 bar pressure at temperature of 100, 200 and 300 °C and pressure (10 bars with retention time of 30, 60 and 90 min. leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 lit was taken and the three methodsWAO, WPO, and a combination of WAO/GAC were used for pre-treatments. Pure oxygen and 30% hydrogen peroxide was used as oxidation agent.Results: The result shows significant improvement on the removal rate of COD (7.8-33.3%, BOD5 (14.7-50.6%by WAO process.The removal efficiency of 4.6-34% COD, 24-50% BOD, was observed in the reactor.Adding theGACto the reactor improved removal efficiency of all parameters.Combination Process (WAO/GAC removed 48% of COD, 31-43.6% of BOD.Combination process demonstrated higher efficiency than two other previous methods as BOD5/COD ratio of 90% achieved.Conclusion: The WAO process presented in this paper is efficient for pretreatment of leachate, And the modified WPO process remove organic materials and ammonia moreover WAO/GAC can be considered as an excellent alternative treatment for removing reluctant organic matter (COD, BOD5 and organic nitrogen compounds, which found in leachate.

  17. Investigation of Saltwater Intrusion and Recirculation of Seawater at a Coastal Boundary

    Science.gov (United States)

    Motz, L. H.; Sedighi, A.

    2012-12-01

    Numerical experiments were conducted to investigate saltwater intrusion and recirculation of seawater at a coastal boundary. A field-scale two-dimensional cross-section was simulated in which freshwater inflow occurred at an upgradient boundary, and saltwater inflow and freshwater outflow and recirculated seawater outflow occurred at a downgradient coastal boundary. The upgradient boundary is a specified-flux boundary with a zero freshwater concentration, and the downgradient boundary is a specified-head boundary with a specified saltwater concentration. This problem was solved using the numerical groundwater flow and transport code SEAWAT for two conditions, i.e., first for the uncoupled condition in which the fluid density is constant and thus the flow and transport equations are uncoupled in a constant-density flowfield, and then for the coupled condition in which the fluid density is a function of the total dissolved solids concentration and thus the flow and transport equations are coupled in a variable-density flowfield. Equivalent freshwater heads were specified at the downstream boundary for both conditions to account for density differences between freshwater and saltwater at the downstream boundary. A range of results for the landward extent of saltwater intrusion and the amount of recirculation of seawater at the coastal boundary was obtained by varying the independent dimensionless ratio of the freshwater inflow relative to the density-driven buoyancy flux, defined as az. For both coupled and uncoupled conditions, it was determined that saltwater intrusion and seawater recirculation are decreased significantly as az is increased. However, the extent of saltwater intrusion is less and the degree of seawater recirculation is greater for the uncoupled condition compared to the coupled condition at smaller values of az, indicating that significant differences can occur between uncoupled and coupled simulations. For the experiments conducted in this

  18. Interaction of Uranium Mill Tailings Leachate with Soils and Clay Liners

    Energy Technology Data Exchange (ETDEWEB)

    Gee, G. W.; Campbell, A. C.; Sherwood, D. R.; Strickert, R. G.; Phillips, S. J.

    1980-06-01

    This study evaluates leachate-soil interactions that will take place at the Morton Ranch for certain disposal alternatives. Laboratory tests were conducted to evaluate the following: 1) physical and chemical characteristics of geologic materials from the Morton Ranch. 2) physical and chemical characteristics of acid leach tailings and tallings solution, 3) leaching tests with selected tailings materials and leach solutions to evaluate the leachability of contaminants with time under specific disposal alternatives, 4) adsorption studies measuring the sorption characteristics of heavy metals and radionuclides on the geologic materials at Morton Ranch, 5) clay liner stability tests to evaluate effects of acid leachate on clay mineralogy and clay permeability.

  19. The Characteristics of Leachate and Groundwater Pollution at Municipal Solid Waste Landfill of Ibb City, Yemen

    Directory of Open Access Journals (Sweden)

    Esmail A. Sabahi

    2009-01-01

    Full Text Available Problem statement: Yemen one of the developing country suffering from water pollution. Landfill is one of the source of water pollution. There are several boreholes located close to Ibb landfill used for drinking water. A study of composition of landfill leachate and groundwater pollution was conducted at Ibb landfill, which is located at Al-Sahool area, north of Ibb City, Yemen. Approach: The leachate was sampled at three different locations of the landfill, at the landfill itself and 15 and 20 m downstream of this landfill. Groundwater samples collected from 5 boreholes to study possible impact of leachate percolation into groundwater. Leachate and groundwater samples were collected during dry season only, due to the excessive generation of leachate during this season. Objective of this study was significant to assess degree of groundwater pollution due to Ibb landfill leachate at Al-Sahool area. The leachate and groundwater were physically and chemically characterized by using spectrophotometer HACH, BOD Trak HACH, flame photometer (PFP 7 and Inductively Coupled Plasma of Optical Emission Spectrometry (ICP-OES model Vista MPX. Parameters measured were pH, temperature, Electrical Conductivity (EC, Total Dissolved Solids (TDS, Dissolved Oxygen (DO, Fluoride (F, Chloride (Cl, Sulphate (SO4, Nitrites (NO2, Nitrates (NO3, ammonia-N (NH3-N, heavy metals (Pb, Zn, Ni, Cr, Cd, Cu, major cations (Na, Mg, Ca, K, Fe and biological parameters (COD, BOD5 and coliform group bacteria. Results: The results showed that, leachate at landfill most likely in methanogenic phase, based on the alkaline pH value recorded (pH = 8.46. The results also showed that 4 out of 5 boreholes were contaminated, where concentration of physico-chemical parameters are above the standard acceptable levels which required for drinking water adapted by Yemen's ministry of water and environment and by word standard. Conclusion: Therefore, landfill is dangerous for environment so

  20. Assessment of soybean (Glycine max vigour by the seed leachate conductivity assay

    Directory of Open Access Journals (Sweden)

    J. S. Knypl

    2015-01-01

    Full Text Available Conductivity of seed leachates is inversely correlated with germination and growth of soybean, Glycine max (L. Merr., at low temperatures. It is concluded that the seed leachate conductivity assay can be employed to assess soybean seed vigour. Cold tolerance of soybean can markedly be enhanced by increasing the hydration level of the seeds to at least 20% by means of exposure of the seeds to HRH (water saturated atmosphere for 4 days. It is suggested that increased vigour following HRH exposure is due to re-establishment of the cell membrane integrity in the course of exposure.

  1. Copper speciation in municipal solid waste incinerator bottom ash leachates; Kopparformer i lakvatten fraan energiaskor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna; Gustafsson, Jon Petter [Royal Inst. of Tech., Stockholm (Sweden); Schaik, Joris van; Berggren Kleja, Dan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Hees, Patrick van [Oerebro Univ. (Sweden)

    2006-03-15

    The formation of copper (Cu) complexes with dissolved organic carbon (DOC) in bottom ash from municipal solid waste incineration (MSWI) may increase the total amount of Cu released but at the same time reduce its toxicity. In this study, DOC in a MSWI bottom ash leachate was characterized and the Cu-binding properties of different DOC fractions in the ash leachate and in a soil solution were studied. This knowledge may be used for improved environmental assessment of MSWI bottom ash in engineering applications. The Cu{sup 2+} activity at different pH values was measured potentiometrically using a Cu-ion selective electrode (Cu-ISE). Experimental copper complexation results were compared to speciation calculations made in Visual MINTEQ with the NICA-Donnan model and the Stockholm Humic Model (SHM). The MSWI bottom ash leachate contained a larger proportion of hydrophilic organic carbon than the investigated soil solution and other natural waters. The hydrophilic fraction of both samples showed Cu{sup 2+} binding properties similar to that of the bulk, cation-exchanged, leachate. For the ash leachate, the pH dependence of the Cu activity was not correctly captured by neither the SHM nor the NICA-Donnan model, but for the soil solution the model predictions of Cu speciation were in good agreement with the obtained results. The complex formation properties of the ash DOC appears to be less pH-dependent than what is assumed for DOC in natural waters. Hence, models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. A Biotic Ligand Model for Daphnia Magna was used to provide an estimate of the copper concentrations at LC50 for a simulated bottom ash leachate. It was concluded that the Cu concentrations in certain bottom ash leachates are high enough to pose an ecotoxicological risk; however, after dilution and soil sorption, the risks for neighboring water bodies are most likely negligible. Three processes were

  2. Performance of Water Recirculation Loop Maintentance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara; Steele, John W.; Bue, Grant C.; Campbell, Colin; Makinen, Janice

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessonslearned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity-compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  3. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  4. Seasonal dynamics in leachate hydrochemistry and natural attenuation in surface run-off water from a tropical landfill.

    Science.gov (United States)

    Mangimbulude, Jubhar C; van Breukelen, Boris M; Krave, Agna S; van Straalen, Nico M; Röling, Wilfred F M

    2009-02-01

    Open waste dump systems are still widely used in Indonesia. The Jatibarang landfill receives 650-700 tons of municipal waste per day from the city of Semarang, Central Java. Some of the leachate from the landfill flows via several natural and collection ponds to a nearby river. The objectives of the study were to identify seasonal landfill leachate characteristics in this surface water and to determine the occurrence of natural attenuation, in particular the potential for biodegradation, along the flow path. Monthly measurements of general landfill leachate parameters, organic matter-related factors and redox-related components revealed that leachate composition was influenced by seasonal precipitation. In the dry season, electrical conductivity and concentrations of BOD, COD, N-organic matter, ammonia, sulphate and calcium were significantly higher (1.1-2.3 fold) than during the wet season. Dilution was the major natural attenuation process acting on leachate. Heavy metals had the highest impact on river water quality. Between the landfill and the river, a fivefold dilution occurred during the dry season due to active springwater infiltration, while rainwater led to a twofold dilution in the wet season. Residence time of leachate in the surface leachate collection system was less than 70 days. Field measurements and laboratory experiments showed that during this period hardly any biodegradation of organic matter and ammonia occurred (less than 25%). However, the potential for biodegradation of organic matter and ammonia was clearly revealed during 700 days of incubation of leachate in the laboratory (over 65%). If the residence time of leachate discharge can be increased to allow for biodegradation processes and precipitation reactions, the polluting effects of leachate on the river can be diminished.

  5. Hydraulic study of parallel channels coupled to recirculation loops; Estudio hidraulico de canales paralelos acoplados a lazos de recirculacion

    Energy Technology Data Exchange (ETDEWEB)

    Campos G, R. M.; Cecenas F, M. [Instituto de Investigaciones Electricas, Av. Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)], e-mail: rmcampos@iie.org.mx

    2009-10-15

    In this work is integrated a model of recirculation loops that allows to characterize each loop for separate and with which is possible to analyze events as shot of recirculation bombs or its transfer of high to low speed. The recirculation pattern is integrated to a model of 36 channels in parallel that represents the core of a BWR. Because the core reactor is conformed by fuel assemblies physically prepared in a parallel arrangement, it is natural to obtain a parallel application of complete pattern, where are have 36 channels tasks more other two tasks that calculates recirculation and punctual kinetics, respectively. As initial test of system, which even it is found in development, was analyzed a discharge of both recirculation pumps. In this test transitory it is only verified the hydraulic behavior, the power is imposed artificially as frontier condition that is function of flow in the calculated core by the recirculation pattern. The pattern of thermal hydraulics channel and the recirculation loops are programmed in language C, the neutronic pattern is programmed in Fortran 77. For the simulations was used a work station Alpha Station DS20E with operative system Unix and the communication system Parallel Virtual Machine, that allows to a heterogeneous collection of computers in net to work like a virtual computer in parallel. (Author)

  6. Simultaneous water desalination and electricity generation in a microbial desalination cell with electrolyte recirculation for pH control

    KAUST Repository

    Qu, Youpeng

    2012-02-01

    A recirculation microbial desalination cell (rMDC) was designed and operated to allow recirculation of solutions between the anode and cathode chambers. This recirculation avoided pH imbalances that could inhibit bacterial metabolism. The maximum power density was 931±29mW/m 2 with a 50mM phosphate buffer solution (PBS) and 776±30mW/m 2 with 25mM PBS. These power densities were higher than those obtained without recirculation of 698±10mW/m 2 (50mM PBS) and 508±11mW/m 2 (25mM PBS). The salt solution (20g/L NaCl) was reduced in salinity by 34±1% (50mM) and 37±2% (25mM) with recirculation (rMDC), and by 39±1% (50mM) and 25±3% (25mM) without recirculation (MDC). These results show that electrolyte recirculation using an rMDC is an effective method to increase power and achieve efficient desalination by eliminating pH imbalances. © 2011 Elsevier Ltd.

  7. Analysis of Bio-Obtainable Endocrine Disrupting Metals in River Water and Sediment, Sewage Influent/Effluent, Sludge, Leachate, and Concentrated Leachate, in the Irish Midlands Shannon Catchment

    Directory of Open Access Journals (Sweden)

    Antoinette M. Reid

    2009-01-01

    Full Text Available The application of an acid digestion and subsequent solid-phase extraction (SPE procedure were implemented as preliminary treatments prior to quantifying the levels of potentially endocrine disrupting metals (EDMs in a variety of solid and liquid matrices. These included (solid river sediment, leachate sediment and sewage sludge and also (liquid river water, landfill leachate, concentrated leachate, sewage influent, and sewage effluent, sampled in the Irish Midlands. The total concentrations of cobalt (Co, cadmium (Cd, copper (Cu, chromium (Cr, nickel (Ni, lead (Pb, zinc (Zn, and manganese (Mn, after extraction and preconcentration, were determined by atomic absorption spectroscopy (AAS. Mercury (Hg in sediment and sludge was determined using cold-vapour atomic fluorescence spectroscopy (AFS. For sewage sludge maximum values (mg/kgdw of 4700 Ni, 1642 Mn, 100.0 Cd, 3400 Zn, 36.70 Co, 750.0 Pb, 485.8 Cr, and 1003 Cu were determined whilst in leachate sediment, maximum values (mg/kgdw of 32.10 Ni, 815.0 Mn, 32.78 Cd, 230.3 Zn, 26.73 Co, 3525 Pb, 124.9 Cr, and 50.13 Cu were found. Over several months, the data showed elevated levels in sewage influents, effluents, and sludges compared to a battery of adjacent river water samples and corresponding sediments. There was a definite trend for target values for sediments to be exceeded, while intervention values were only exceeded for cadmium. Overall the pattern in terms of concentration was sewage > leachate > river matrices. A nonparametric assessment of the effect of sewage treatment method on median metal levels in sludge revealed statistically significant differences at the 95% level of confidence for Co, Cr, and Hg and at the 90% level of confidence for Cd.

  8. Effect of self recirculation casing treatment on the performance of a turbocharger centrifugal compressor

    Science.gov (United States)

    Gancedo, Matthieu

    Increase in emission regulations in the transport industry brings the need to have more efficient engines. A path followed by the automobile industry is to downsize the size of the internal combustion engine and increase the air density at the intake to keep the engine power when needed. Typically a centrifugal compressor is used to force the air into the engine, it can be powered from the engine shaft (superchargers) or extracting energy contained into the hot exhaust gases with a turbine (turbochargers). The flow range of the compressor needs to match the one of the engine. However compressors mass flow operating range is limited by choke on the high end and surge on the low end. In order to extend the operation at low mass flow rates, the use of passive devices for turbocharger centrifugal compressors was explored since the late 80's. Hence, casing treatments including flow recirculation from the inducer part of the compressor have been shown to move the surge limit to lower flows. Yet, the working mechanisms are still not well understood and thus, to optimize the design of this by-pass system, it is necessary to determine the nature of the changes induced by the device both on the dynamic stability of the pressure delivery and on the flow at the inlet. The compressor studied here features a self-recirculating casing treatment at the inlet. The recirculation passage could be blocked to carry a direct comparison between the cases with and without the flow feature. To grasp the effect on compressor stability, pressure measurements were taken in the different constituting elements of the compressor. The study of the mean pressure variations across the operating map showed that the tongue region is a limiting element. Dynamic pressure measurements revealed that the instabilities generated near the inducer when the recirculation is blocked increase the overall instability levels at the compressor outlet and propagating pressure waves starting at the tongue occurred

  9. Transmission electron microscopy investigation of colloids and particles from landfill leachates.

    Science.gov (United States)

    Matura, Marek; Ettler, Vojtech; Klementová, Mariana

    2012-05-01

    Leachates collected at two (active and closed) municipal solid waste (MSW) landfills were examined for colloids and particles by transmission electron microscopy, energy dispersive spectrometry, selected area electron diffraction and for the chemical compositions of the filtrates after the filtration to 0.1 µm and ultrafiltration to 1 kDa (~ 1 nm). Six groups of colloids/particles in the range 5 nm to 5 µm were determined (in decreasing order of abundance): carbonates, phyllosilicates (clay minerals and micas), quartz, Fe-oxides, organics and others (salts, phosphates). Inorganic colloids/particles in leachates from the active landfill predominantly consist of calcite (CaCO(3)) and minor clay minerals and quartz (SiO(2)). The colloids/particles in the leachates from the closed landfill consist of all the observed groups with dominant phyllosilicates. Whereas calcite, Fe-oxides and phosphates can precipitate directly from the leachates, phyllosilicates and quartz are more probably either derived from the waste or formed by erosion of the geological environment of the landfill. Low amounts of organic colloids/particles were observed, indicating the predominance of organic molecules in the 'truly dissolved' fraction (fulvic compounds). Especially newly formed calcite colloids forming particles of 500 nm and stacking in larger aggregates can bind trace inorganic contaminants (metals/metalloids) and immobilize them in landfill environments.

  10. Characterization of DOM in landfill leachate polluted groundwater with electrospary LC-MS

    DEFF Research Database (Denmark)

    Persson, L.; Alsberg, T.; Odham, G.

    2001-01-01

    Dissolved organic matter in leachate polluted groundwater, downgradient a landfill, was analysed with electrospray mass spectrometry. The results indicate that the DOM change qualitatively in the gradient, becoming more uniform in functional groups and hydrofobicity. Those changes may affect...... the DOM facilitated transport of pollutants....

  11. Systematic model development for partial nitrification of landfill leachate in a SBR

    DEFF Research Database (Denmark)

    Ganigue, R.; Volcke, E.I.P.; Puig, S.

    2010-01-01

    This study deals with partial nitrification in a sequencing batch reactor (PN-SBR) treating raw urban landfill leachate. In order to enhance process insight (e.g. quantify interactions between aeration, CO2 stripping, alkalinity, pH, nitrification kinetics), a mathematical model has been set up...

  12. Remediation of leachate by composite NZVI-activated carbon in packed column

    Directory of Open Access Journals (Sweden)

    Sri Yusmartini Eka

    2017-01-01

    Full Text Available Improper solid waste management at final disposal site can cause in environtmental problem. The surrounding water bodies could be affected by leachate from the solid waste decomposition process because leachate contains high concentration of BOD5, COD, ammonia, hydrocarbon suspended solid, and heavy metals. This problem has affected a final disposal site (named Sukawinatan in Palembang, Indonesia, which did not implement leachate management system. This paper propose a method to reduce BOD5, COD, Ammonia concentrations of the leachate in by applying composite nano zero valent iron (NZVI – activated carbon for the remediation system of the surrounding area of Sukawinatan final disposal. The performance of the method was evaluated in this study using laboratory porous column apparatus. The results showed that the composite NZVI-activated carbon can be used to reduce concentration of pollutants from water bodies. The removal efficiency of this method on BOD5, COD and ammonia are 94.81 %, 92.81 % dan 95.58 % respectively.

  13. Treatment of landfill leachate by using lateritic soil as a natural coagulant.

    Science.gov (United States)

    Syafalni; Lim, Han Khim; Ismail, Norli; Abustan, Ismail; Murshed, Mohamad Fared; Ahmad, Anees

    2012-12-15

    In this research, the capability of lateritic soil used as coagulant for the treatment of stabilized leachate from the Penang-Malaysia Landfill Site was investigated. The evaluation of lateritic soil coagulant in comparison with commercialized chemical coagulants, such as alum, was performed using conventional jar test experiments. The optimum pH and coagulant dosage were identified for the lateritic soil coagulant and the comparative alum coagulant. It was found that the application of lateritic soil coagulant was quite efficient in the removal of COD, color and ammoniacal-nitrogen content from the landfill leachate. The optimal pH value was 2.0, while 14 g/L of lateritic soil coagulant was sufficient in removing 65.7% COD, 81.8% color and 41.2% ammoniacal-nitrogen. Conversely, the optimal pH and coagulant dosage for the alum were pH 4.8 and 10 g/L respectively, where 85.4% COD, 96.4% color and 47.6% ammoniacal-nitrogen were removed from the same leachate sample. Additionally, the Sludge Volume Index (SVI) ratio of alum and lateritic soil coagulant was 53:1, which indicated that less sludge was produced and was an environmentally friendly product. Therefore, lateritic soil coagulant can be considered a viable alternative in the treatment of landfill leachate.

  14. Leachates analysis of glass from black and white and color televisions sets

    Directory of Open Access Journals (Sweden)

    Radovan Kukla

    2012-01-01

    Full Text Available The aim of work was to determine the content of selected elements in the glass from color and black and white television (TV sets. The amount of back taken TV sets in the Czech Republic increases annualy, which is associated with higher production of the waste glass. Currently there is 1.4 television sets for each household and the number of it should increase in future, because of higher standard of living and new technologies used. Waste glass treatment or landfilling may present, because of composition of the waste glass threat to the environment. One of the indicators of the polution from waste glass is leachate analysis, which can show us the content of hazardous substances in the waste glass, which can be released to the environment. A qualitative analysis of leachate samples was carried out by UV-VIS spectrophotometer. The results showed concentration of potencionaly hazardous substances contained in leachate samples. This was especially content of aluminum, cadmium, chromium, copper, molybdenum, nickel, lead, tin and zinc. Results of analyzes of the aqueous extract of glass were confronted with the limits specified in the currently valid legislation. Based on the results there is clear that in the case of landfilling of the glass from television sets, there is possibility of the contamination of landfill leachate by the elements, which are presented in the glass.

  15. Treatment of landfill leachate by white rot fungus in combination with zeolite filters.

    Science.gov (United States)

    Kim, Yeong-Kwan; Park, Se-Kun; Kim, Seung-Do

    2003-04-01

    This article presents the experimental work for the treatment of landfill leachate in a combined process using the white rot fungus Phanerochaete chrysosporium and the natural zeolite Clinoptilolite. Clinoptilolite was used in a pretreatment step as a sink for ammonia nitrogen and, on average it reduced the levels of ammonia nitrogen, soluble chemical oxygen demand (COD) and color by 72, 4.7, and 25%, respectively. The reductions by fungal treatment alone were 16.6, 21.5, and 31.2%, respectively. However, a reduction in nitrogen loading greatly enhanced fungal treatment efficiency. A high C/N ratio in the leachate was found preferable for the fungal treatment. With the synergy created by pretreatment and fungal growth that was stimulated by the addition of a growth medium, the process could remove ammonia nitrogen, soluble COD (SCOD) and color at levels as high as 81.5, 65, and 59%, respectively. The ratio of SBOD5/SCOD increased from 0.1 to 0.17 upon treatment, indicating that the process rendered the leachate more amenable to the biological process. This result suggested that the preliminary reduction of ammonia nitrogen was essential in making the fungal process practicable for landfill leachate treatment.

  16. Reactive transport modelling of biogeochemical processes and carbon isotope geochemistry inside a landfill leachate plume.

    Science.gov (United States)

    van Breukelen, Boris M; Griffioen, Jasper; Röling, Wilfred F M; van Verseveld, Henk W

    2004-06-01

    The biogeochemical processes governing leachate attenuation inside a landfill leachate plume (Banisveld, the Netherlands) were revealed and quantified using the 1D reactive transport model PHREEQC-2. Biodegradation of dissolved organic carbon (DOC) was simulated assuming first-order oxidation of two DOC fractions with different reactivity, and was coupled to reductive dissolution of iron oxide. The following secondary geochemical processes were required in the model to match observations: kinetic precipitation of calcite and siderite, cation exchange, proton buffering and degassing. Rate constants for DOC oxidation and carbonate mineral precipitation were determined, and other model parameters were optimized using the nonlinear optimization program PEST by means of matching hydrochemical observations closely (pH, DIC, DOC, Na, K, Ca, Mg, NH4, Fe(II), SO4, Cl, CH4, saturation index of calcite and siderite). The modelling demonstrated the relevance and impact of various secondary geochemical processes on leachate plume evolution. Concomitant precipitation of siderite masked the act of iron reduction. Cation exchange resulted in release of Fe(II) from the pristine anaerobic aquifer to the leachate. Degassing, triggered by elevated CO2 pressures caused by carbonate precipitation and proton buffering at the front of the plume, explained the observed downstream decrease in methane concentration. Simulation of the carbon isotope geochemistry independently supported the proposed reaction network.

  17. Hollow-fiber membrane bioreactor for the treatment of high-strength landfill leachate

    KAUST Repository

    Rizkallah, Marwan

    2013-07-15

    Performance assessment of membrane bioreactor (MBR) technology for the treatability of high-strength landfill leachate is relatively limited or lacking. This study examines the feasibility of treating high-strength landfill leachate using a hollow-fiber MBR. For this purpose, a laboratory-scale MBR was constructed and operated to treat leachate with a chemical oxygen demand (COD) of 9000-11,000 mg/l, a 5-day biochemical oxygen demand (BOD5) of 4000-6,000 mg/l, volatile suspended solids (VSS) of 300-500 mg/l, total nitrogen (TN) of 2000-6000 mg/l, and an ammonia-nitrogen (NH3-N) of 1800-4000 mg/l. VSS was used with the BOD and COD data to simulate the biological activity in the activated sludge. Removal efficiencies > 95-99% for BOD5, VSS, TN and NH3-N were attained. The coupled experimental and simulation results contribute in filling a gap in managing high-strength landfill leachate and providing guidelines for corresponding MBR application. © The Author(s) 2013.

  18. Ecotoxicological evaluation of leachate from the Limeira sanitary landfill with a view to identifying acute toxicity

    Directory of Open Access Journals (Sweden)

    José Euclides Stipp Paterniani

    2007-12-01

    Full Text Available Final disposal of solid waste is still a cause for serious impacts on the environment. In sanitary landfills, waste undergoes physical, chemical, and biological decomposition, generating biogas and leachate. Leachate is a highly toxic liquid with a very high pollution potential. The purpose of this work is to evaluate toxicity of in natura leachate samples collected from Limeira Sanitary Landfill, in Limeira, SP. The ecotoxicological evaluation comprised acute toxicity assays using as test organisms Daphnia Similis, seeds of Eruca sativa (arugula, and Allium cepa roots (onion. Analyses of color, pH, turbidity, conductivity, hardness, nitrogen, total organic carbon (TOC, adsorbable organic halogen (AOX, and metals were also carried out. The main results for Eruca sativa (arugula and Allium cepa (onion indicated that the diluted leachate 50% presented similar toxicity to the phenol solution of 1000 mg.L-1 for arugula and 2000 mg.L-1 for onion. With the solution of Cr+6 concentrations of 3000 mg.L-1 for arugula and 2000 mg.L-1 for onion were found. For analyses with Daphnia Similis the EC50 was 9.3% on average. This way it was possible to observe that biological tests are necessary to evaluate the pollution in the effluents or water bodies. These tests serve to determine the toxic potential of a chemical agent or complex mixture.

  19. Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes.

    Science.gov (United States)

    Oturan, Nihal; van Hullebusch, Eric D; Zhang, Hui; Mazeas, Laurent; Budzinski, Hélène; Le Menach, Karyn; Oturan, Mehmet A

    2015-10-20

    In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals ((•)OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants.

  20. Mono- and diesters from o-phthalic acid in leachates from different European landfills

    DEFF Research Database (Denmark)

    Jonsson, S.; Eilertsson, J.; Ledin, Anna;

    2003-01-01

    Leachates from 17 different landfills in Europe were, analysed with respect to phthalates, i.e. phthalic acid diesters (PAEs) and their degradation products phthalic acid monoesters (PMEs) and ortho-phthalic acid (PA). Diesters are ubiquitous and the human possible exposure and potential to human...

  1. Selecting and utilizing Populus and Salix for landfill covers: implications for leachate irrigation

    Science.gov (United States)

    Ronald S., Jr. Zalesny; Edmund O. Bauer

    2007-01-01

    The success of using Populus and Salix for phytoremediation has prompted further use of leachate as a combination of irrigation and fertilization for the trees. A common protocol for such efforts has been to utilize a limited number of readily-available genotypes with decades of deployment in other applications, such as fiber or...

  2. APPLICATION OF THERMAL PLASMA FOR INERTIZATION OF SLUDGE PRODUCED DURING TREATMENT OF LANDFILL LEACHATE

    Directory of Open Access Journals (Sweden)

    Anelise Leal Vieira Cubas

    Full Text Available One of the outstanding issues of concern by governments and society in general relates to the final destination of solid waste, which can bring severe impacts on social, political, economic and environmental dimensions. The sustainable development of enterprises and industries goes for the care of the planet, thus ensuring the quality of life for future generations and the planet. The disposal of municipal waste in landfills is the technique most commonly employed for the remediation of solid residues. The residues undergo decomposition beneath the soil and in the presence of water this generates leachate, which percolates down to the bottom of the landfill through drainage. This drained liquid is collected from the landfill installations and subjected to treatment, which involves physico-chemical and biological processes. Landfill leachate commonly contains heavy metals due to the incorrect disposal of products such as fluorescent bulbs and batteries. In this context, a method for the treatment of sludge originating from the physicochemical remediation of leachate using thermal plasma is proposed in this paper. The efficiency of the method was verified by monitoring the total organic carbon content, water content and density of the sludge. The quantity of metals present in the samples was determined before and after pyrolysis by thermal plasma using flame atomic absorption spectroscopy (FAAS, scanning electron microscopy (SEM and X-ray fluorescence (XRF spectrometry techniques. The results show that the leachate treatment method used was efficient, presenting the best results for the samples of iron and zinc.

  3. Monitoring transitory profiles of leachate humic substances in landfill aeration reactors in mesophilic and thermophilic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Huanhuan [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Yin, Ke; Ge, Liya; Giannis, Apostolos [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); Chuan, Valerie W.L. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Wang, Jing-Yuan, E-mail: JYWANG@ntu.edu.sg [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2015-04-28

    Highlights: • Polymerization and condensation of humic substances (HS) were enhanced by aeration. • Carboxylic group was enriched in HS by aeration presenting improved hydrophilicity. • Mobility of humic acid, as a result was enhanced by aeration especially in young landfill. • Waste age plays an important role in leachate management during aeration. - Abstract: The presence of humic substances (HS) in landfill leachate is of great interest because of their structural stability and potential toxicity. This study examined the effects of temperature and waste age on the transformation of HS during in situ aeration of bioreactor landfills. By establishing aerobic conditions, dissolved organic carbon (DOC) rapidly accumulated in the bioreactor leachate. Fractional analysis showed that the elevated concentration of humic acids (HAs) was primarily responsible for the increment of leachate strength. Further structural characterization indicated that the molecular weight (MW) and aromacity of HS were enhanced by aeration in conjunction with thermophilic temperature. Interestingly, elevation of HAs concentration was not observed in the aeration reactor with a prolonged waste age, as the mobility of HAs was lowered by the high MW derived from extended waste age. Based on these results, aeration may be more favorable in aged landfills, since dissolution of HAs could be minimized by the evolution to larger MW compared to young landfills. Moreover, increased operation temperature during aeration likely offers benefits for the rapid maturation of HS.

  4. Assessment of groundwater contamination by landfill leachate: a case in México.

    Science.gov (United States)

    Reyes-López, Jaime A; Ramírez-Hernández, Jorge; Lázaro-Mancilla, Octavio; Carreón-Diazconti, Concepción; Garrido, Miguel Martín-Loeches

    2008-01-01

    In México, uncontrolled landfills or open-dumps are regularly used as "sanitary landfills". Interactions between landfills/open-dumps and shallow unconfined aquifers have been widely documented. Therefore, evidence showing the occurrence of aquifer contamination may encourage Mexican decision makers to enforce environmental regulations. Traditional methods such as chemical analysis of groundwater, hydrological descriptions, and geophysical studies including vertical electrical sounding (VES) and ground penetrating radar (GPR) were used for the identification and delineation of a contaminant plume in a shallow aquifer. The Guadalupe Victoria landfill located in Mexicali is used as a model study site. This landfill has a shallow aquifer of approximately 1m deep and constituted by silty sandy soil that may favor the transport of landfill leachate. Geophysical studies show a landfill leachate contaminant plume that extends for 20 and 40 m from the SE and NW edges of the landfill, respectively. However, the zone of the leachate's influence stretches for approximately 80 m on both sides of the landfill. Geochemical data corroborates the effects of landfill leachate on groundwater.

  5. Investigation of organic, inorganic and synthetic adsorbents for the pretreatment of landfill leachate.

    Science.gov (United States)

    Shahriari, H; Fernandes, L; Tezel, F H

    2008-05-01

    An investigation into the use of organic, inorganic and synthetic adsorbents for the pretreatment of landfill leachate, generated by the City of Ottawa Trail Road Landfill, was carried out. The purpose of this project was to reduce the concentration of contaminants in order to meet the local Sewer Use By-Laws, prior to transporting the leachate from the generating site to the local municipal sewage treatment plant, and thereby reducing the disposal fees. Peat moss, compost, clinoptilolite, basalt and two types of activated carbon (DSR-A and F400) were investigated to determine the adsorption capacity for contaminants from leachate. Kinetic studies were also performed. The results based on batch adsorption isotherms show that peat moss has the highest adsorption capacity for boron (B) and barium (Ba), compared with the other adsorbents. Also peat moss has good removals of Total Kjeldahl Nitrogen (TKN), Total Organic Carbon (TOC), and benzene, toluene, ethylbenzene and xylene (BTEX), but these are lower than the removals obtained with activated carbon. Because of its relatively low cost and higher adsorption of B and Ba, peat moss was selected as the filter media for the column studies. The treated leachate was tested for B, Ba, TKN, carbonaceous biological oxygen demand (CBOD5) and hydrogen sulfide (H2S). The breakthrough curves for B and Ba showed the effectiveness of peat moss in removing these contaminants.

  6. Adsorption of valuable metals from leachates of mobile phone wastes using biopolymers and activated carbon.

    Science.gov (United States)

    Zazycki, Maria A; Tanabe, Eduardo H; Bertuol, Daniel A; Dotto, Guilherme L

    2017-03-01

    In this work, chitin (CTN), chitosan (CTS) and activated carbon (AC) were used as adsorbents to recover valuable metals from leachates of mobile phone wastes. The mobile phone wastes (contactors) were collected and characterized. The valuable metals were extracted by thiourea leaching. The adsorption of valuable metals from leachates was studied according to the kinetic and equilibrium viewpoints. It was found that the contactors were composed by Au, Ni, Cu and Sn. The thiourea leaching provided extraction percentages of 68.6% for Au, 22.1% for Ni and 2.8% for Cu. Sn was not extracted. The leachate presented 17.5 mg L(-1) of Au, 324.9 mg L(-1) of Ni and 573.1 mg L(-1) of Cu. The adsorption was fast, being the equilibrium attained within 120 min. The adsorption of Au, Ni and Cu onto CTN and AC followed the Langmuir model, while, the adsorption of these metals onto CTS, followed the Freundlich model. Removal percentages higher than 95% were obtained for all metals, depending of the type and amount of adsorbent. It was demonstrated that the adsorption onto chitin, chitosan and activated carbon can be an alternative to recover valuable metals from leachates of mobile phone wastes.

  7. Size charge fractionation of metals in municipal solid waste landfill leachate.

    Science.gov (United States)

    Oygard, Joar Karsten; Gjengedal, Elin; Røyset, Oddvar

    2007-01-01

    Municipal solid waste landfill leachates from 9 Norwegian sites were size charge fractionated in the field, to obtain three fractions: particulate and colloidal matter >0.45microm, free anions/non-labile complexes 0.45microm. Cr, Co and Ni were on the contrary present mostly as non-labile complexes (69-79%) 0.45microm. The particulate and colloidal matter >0.45microm was mainly inorganic; indicating that the metals present in this fraction were bound as inorganic compounds. The fractionation gives important information on the mobility and potential bioavailability of the metals investigated, in contrast to the total metal concentrations usually reported. To study possible changes in respective metal species in leachate in aerated sedimentation tanks, freshly sampled leachate was stored for 48h, and subsequently fractionated. This showed that the free heavy metals are partly immobilized during storage of leachate with oxygen available. The largest effects were found for Cd and Zn. The proportion of As and Cr present as particulate matter or colloids >0.45microm also increased.

  8. Characteristics of dissolved organic matter (DOM) in leachate with different landfill ages

    Institute of Scientific and Technical Information of China (English)

    HUO Shouliang; XI Beidou; YU Haichan; HE Liansheng; FAN Shilei; LIU Hongliang

    2008-01-01

    The main objective of the study was to investigate the characteristics of dissolved organic matter (DOM) in leachate with different landfill ages through the chemical, spectroscopic, and elemental analysis. Humic acid (HA), fulvic acid (FA), and hydrophilic (HyI) fractions were isolated and purified by the XAD-8 resin combined with the cation exchange resin method. The analytical results of fluorescence excitation-emission matrix spectroscopy (EEMs) revealed that the fluorescence peaks were protein-like fluorescence for young landfill leachate, while the fluorescence peaks for medium and old landfill leachate were humic-like and fulvic-like fluorescence, respectively. Elemental analysis showed that carbon, hydrogen, and nitrogen content decreased with landfill age, while the oxygen content increased. Moreover, the nitrogen content in these isolated fractions followed: HA > HyI > FA. The results of elemental analysis, FT-IR, and fluorescence EEMs also confirmed that aromatic carbons and portions of aliphatic functional groups were more abundant in leachate samples with increasing landfill age.

  9. Mobilization of iron and arsenic from soil by construction and demolition debris landfill leachate.

    Science.gov (United States)

    Wang, Yu; Sikora, Saraya; Kim, Hwidong; Dubey, Brajesh; Townsend, Timothy

    2012-05-01

    Column experiments were performed to examine (a) the potential for leachate from construction and demolition (C&D) debris landfills to mobilize naturally-occurring iron and arsenic from soils underlying such facilities and (b) the ability of crushed limestone to remove these aqueous phase pollutants. In duplicate columns, water was added to a 30-cm layer of synthetic C&D debris, with the resulting leachate serially passed through a 30-cm soil layer containing iron and arsenic and a 30-cm crushed limestone layer. This experiment was conducted for two different soil types (one high in iron (10,400mg/kg) and the second high in iron (5400mg/kg) and arsenic (70mg/kg)); also monitored were control columns for both soil types with water infiltration alone. Despite low iron concentrations in the simulated C&D debris leachate, elevated iron concentrations were observed when leachate passed through the soils; reductive dissolution was concluded to be the cause of iron mobilization. In the soil containing elevated arsenic, increased iron mobilization from the soil was accompanied by a similar but delayed arsenic mobilization. Since arsenic sorbs to oxidized iron soil minerals, reductive dissolution of these minerals results in arsenic mobilization. Crushed limestone significantly reduced iron (to values below the detection limit of 0.01mg/L in most cases); however, arsenic was not removed to any significant extent.

  10. EFEKTIVITAS ECENG GONDOK (Echhornia crassipes DALAM PENYERAPAN KADMIUM (Cd PADA LEACHATE TPA GUNUNG TUGEL

    Directory of Open Access Journals (Sweden)

    Sri Lestari

    2011-05-01

    Full Text Available Leachate is liquid of result organic garbage that contain substance is dissolved and suspension as decomposition by microorganism. Leachate contain material organic with high level and many formed at landfill with open dumping system. Material organic in leachate can be reduced by phytoremediation with water hyacinth (Echhornia crassipes. The aim of research are know large closure of water hyacinth, long residence time and the best interaction to reduce the levels of material organic in leachate. Method of research was designed experimental based on Completely Randomized Design (CRD with Factorial Design. The first factor are closing large percentage of water hyacinth (0%, 25%, 50%, 75% and 100% and the second factor are long residence time (4 days, 5 days and 6 days. Result of research showed that is closing large of 75% is the best treatment to reducing level of Cd that is 29,279%. and long residence time of 6 days is the best treatment to reducing level of Cd that is 27,211%. Interaction closing large of 75% and long residence time of 6 days is the best treatment to reducing level of Cd that is 39,770%

  11. Marine Microcosm Experiments on Effects of Copper and Tributylin-Based Antifouling Paint Leachates

    Science.gov (United States)

    1988-06-01

    several years to examine the effects on benthos of common harbor pollutants, such as sewage nutrients, heavy metals, excess heat, fresh water, and...EFFECTS OF ANTIFOULING LEACHATES ON TWO SPECIES OF CORAL INTRODUCTION Many species of inshore stony corals are potentially useful as bioindicators of

  12. Limiting Factors for Microbial Fe(III)-Reduction In a Landfill Leachate Polluted Aquifer (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Albrechtsen, Hans-Jørgen; Heron, Gorm; Christensen, Thomas Højlund

    1995-01-01

    Aquifer sediment samples from two locations within the anaerobic leachate plume of a municipal landfill were compared with respect to microbiology (especially Fe(III)-reduction) and geochemistry. The samples close to the landfill were characterized by low contents of Fe(III), whereas samples from...

  13. Cytogenetic effects of leachates from tannery solid waste on the somatic cells of Vicia faba.

    Science.gov (United States)

    Chandra, Saurabh; Chauhan, L K S; Pande, P N; Gupta, S K

    2004-04-01

    The contamination of surface- and groundwater by the leaching of solid wastes generated by industrial activities as a result of water runoff and rainfall is a matter of great concern. The leachates from tannery solid waste (TSW), a major environmental pollutant, were examined for their possible genotoxic effects on the somatic cells of Vicia faba. Leachates were prepared from solid wastes procured from leather-tanning industrial sites, and V. faba seedlings were exposed to three test concentrations, 2.5%, 5%, and 10%, through soil and aqueous media for 5 days. The root tips examined for cytogenetic damage revealed that leachate of TSW significantly inhibited the mitotic index and induced significantly frequent chromosomal and mitotic aberrations (CA/MA) in a dose-dependent manner. The chemical analysis of TSW samples revealed that the chief constituents were chromium and nickel, which may cause genetic abnormalities. The frequency of aberrations was found to be higher in the root meristematic cells of Vicia faba exposed through the aqueous medium than those exposed through the soil medium. The results of the present study indicated that contamination of potable water bodies by leachates of TSW may cause genotoxicity. For the biomonitoring of complex mixtures of toxicants with the V. faba bioassay, the use of the aqueous medium seems to be a more promising method than the use of the soil medium.

  14. Comparison of long-term performances and final microbial compositions of anaerobic reactors treating landfill leachate

    NARCIS (Netherlands)

    Calli, B.; Mertoglu, B.; Roest, C.; Inanc, B.

    2006-01-01

    Laboratory scale anaerobic upflow filter, sludge blanket and hybrid bed reactors were operated for 860 days in the treatment of high ammonia landfill leachate. Organic loading was gradually increased from 1.3 to 23.5 kg COD/m3 day in the start-up period and then fluctuated according to the COD conce

  15. Natural attenuation processes in landfill leachate plumes at three Danish sites

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Tuxen, Nina; Reitzel, Lotte;

    2011-01-01

    This article provides an overview of comprehensive core and fringe field studies at three Danish landfill sites. The goal of the research activities is to provide a holistic description of core and fringe attenuation processes for xenobiotic organic compounds in landfill leachate plumes. The appr...

  16. Irrigating poplar energy crops with landfill leachate negatively affects soil micro- and meso-fauna.

    Science.gov (United States)

    Coyle, David R; Zalesny, Jill A; Zalesny, Ronald S; Wiese, Adam H

    2011-10-01

    Increased municipal solid waste generated worldwide combined with substantial demand for renewable energy has prompted testing and deployment of woody feedstock production systems that reuse and recycle wastewaters as irrigation and fertilization. Populus selections are ideal for such systems given their fast growth, extensive root systems, and high water usage rates. Maintaining ecological sustainability (i.e., the capacity for an ecosystem to maintain its function and retain its biodiversity over time) during tree establishment and development is an important component of plantation success, especially for belowground faunal populations. To determine the impact of solid waste leachate on soil micro- and meso-fauna, we compared soilfrom eight different Populus clones receiving municipal solid waste landfill leachate irrigation with clones receiving fertilized (N, P K) well water irrigation. Microfauna (i.e., nematodes) communities were more diverse in control soils. Mesofauna (i.e., insects) were associated with all clones; however, they were four times more abundant around trees found within the control plot than those that received leachate treatments. Nematode and insect abundance varied among Populus clones yet insect diversity was greater in the leachate-treated soils. Phytotechnologies must allow for soil faunal sustainability, as upsetting this balance could lead to great reductions in phytotechnology efficacy.

  17. Removal of hydrogen sulfide gas and landfill leachate treatment using coal bottom ash.

    Science.gov (United States)

    Lin, C Y; Hesu, P H; Yang, D H

    2001-06-01

    Coal bottom ashes produced from three thermal power plants were used in column and batch experiments to investigate the adsorption capacity of the coal ash. Hydrogen sulfide and leachates collected from three sanitary landfill sites were used as adsorbate gas and solutions, respectively. Experimental results showed that coal bottom ash could remove H2S from waste gas or reduce the concentrations of various pollutants in the leachate. Each gram of bottom ash could remove up to 10.5 mg of H2S. In treating the landfill leachate, increasing ash dosage increased the removal efficiency but decreased the adsorption amount per unit mass of ash. For these tested ashes, the removal efficiencies of chemical oxygen demand (COD), NH3-N, total Kjeldhal nitrogen (TKN), P, Fe3+, Mn2+, and Zn2+ were 36.4-50, 24.2-39.4, 27.0-31.1, 82.2-92.9, 93.8-96.5, 93.7-95.4, and 80.5-82.2%, respectively; the highest adsorption capacities for those parameters were 3.5-5.6, 0.22-0.63, 0.36-0.45, 0.027-0.034, 0.050-0.053, 0.029-0.032, and 0.006 mg/g of bottom ash, respectively. The adsorption of pollutants in the leachate conformed to Freundlich's adsorption model.

  18. Leachate/domestic wastewater aerobic co-treatment: A pilot-scale study using multivariate analysis.

    Science.gov (United States)

    Ferraz, F M; Bruni, A T; Povinelli, J; Vieira, E M

    2016-01-15

    Multivariate analysis was used to identify the variables affecting the performance of pilot-scale activated sludge (AS) reactors treating old leachate from a landfill and from domestic wastewater. Raw leachate was pre-treated using air stripping to partially remove the total ammoniacal nitrogen (TAN). The control AS reactor (AS-0%) was loaded only with domestic wastewater, whereas the other reactor was loaded with mixtures containing leachate at volumetric ratios of 2 and 5%. The best removal efficiencies were obtained for a ratio of 2%, as follows: 70 ± 4% for total suspended solids (TSS), 70 ± 3% for soluble chemical oxygen demand (SCOD), 70 ± 4% for dissolved organic carbon (DOC), and 51 ± 9% for the leachate slowly biodegradable organic matter (SBOM). Fourier transform infrared (FTIR) spectroscopic analysis confirmed that most of the SBOM was removed by partial biodegradation rather than dilution or adsorption of organics in the sludge. Nitrification was approximately 80% in the AS-0% and AS-2% reactors. No significant accumulation of heavy metals was observed for any of the tested volumetric ratios. Principal component analysis (PCA) and partial least squares (PLS) indicated that the data dimension could be reduced and that TAN, SCOD, DOC and nitrification efficiency were the main variables that affected the performance of the AS reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Experimental evidence of colloids and nanoparticles presence from 25 waste leachates.

    Science.gov (United States)

    Hennebert, Pierre; Avellan, Astrid; Yan, Junfang; Aguerre-Chariol, Olivier

    2013-09-01

    The potential colloids release from a large panel of 25 solid industrial and municipal waste leachates, contaminated soil, contaminated sediments and landfill leachates was studied. Standardized leaching, cascade filtrations and measurement of element concentrations in the microfiltrate (MF) and ultrafiltrate (UF) fraction were used to easily detect colloids potentially released by waste. Precautions against CO(2) capture by alkaline leachates, or bacterial re-growth in leachates from wastes containing organic matter should be taken. Most of the colloidal particles were visible by transmission electron microscopy with energy dispersion spectrometry (TEM-EDS) if their elemental MF concentration is greater than 200 μgl(-1). If the samples are dried during the preparation for microscopy, neoformation of particles can occur from the soluble part of the element. Size distribution analysis measured by photon correlation spectroscopy (PCS) were frequently unvalid, particularly due to polydispersity and/or too low concentrations in the leachates. A low sensitivity device is required, and further improvement is desirable in that field. For some waste leachates, particles had a zeta potential strong enough to remain in suspension. Mn, As, Co, Pb, Sn, Zn had always a colloidal form (MF concentration/UF concentration>1.5) and total organic carbon (TOC), Fe, P, Ba, Cr, Cu, Ni are partly colloidal for more than half of the samples). Nearly all the micro-pollutants (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Sb, Sn, V and Zn) were found at least once in colloidal form greater than 100 μgl(-1). In particular, the colloidal forms of Zn were always by far more concentrated than its dissolved form. The TEM-EDS method showed various particles, including manufactured nanoparticles (organic polymer, TiO(2), particles with Sr, La, Ce, Nd). All the waste had at least one element detected as colloidal. The solid waste leachates contained significant amount of colloids different in elemental

  20. Attenuation of landfill leachate by UK Triassic sandstone aquifer materials. 2. Sorption and degradation of organic pollutants in laboratory columns

    Science.gov (United States)

    Thornton, Steven F.; Bright, Mildred I.; Lerner, David N.; Tellam, John H.

    2000-05-01

    The sorption and degradation of dissolved organic matter (DOM) and 13 organic micropollutants (BTEX, aromatic hydrocarbons, chloro-aromatic and -aliphatic compounds, and pesticides) in acetogenic and methanogenic landfill leachate was studied in laboratory columns containing Triassic sandstone aquifer materials from the English Midlands. Solute sorption and degradation relationships were evaluated using a simple transport model. Relative to predictions, micropollutant sorption was decreased up to eightfold in acetogenic leachate, but increased up to sixfold in methanogenic leachate. This behaviour reflects a combination of interactions between the micropollutants, leachate DOM and aquifer mineral fraction. Sorption of DOM was not significant. Degradation of organic fractions occurred under Mn-reducing and SO 4-reducing conditions. Degradation of some micropollutants occurred exclusively under Mn-reducing conditions. DOM and benzene were not significantly degraded under the conditions and time span (up to 280 days) of the experiments. Most micropollutants were degraded immediately or after a lag phase (32-115 days). Micropollutant degradation rates varied considerably (half-lives of 8 to >2000 days) for the same compounds (e.g., TeCE) in different experiments, and for compounds (e.g., naphthalene, DCB and TeCA) within the same experiment. Degradation of many micropollutants was both simultaneous and sequential, and inhibited by the utilisation of different substrates. This mechanism, in combination with lag phases, controls micropollutant degradation potential in these systems more than the degradation rate. These aquifer materials have a potentially large capacity for in situ bioremediation of organic pollutants in landfill leachate and significant degradation may occur in the Mn-reducing zones of leachate plumes. However, degradation of organic pollutants in acetogenic leachate may be limited in aquifers with low pH buffering capacity and reducible Mn oxides