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Sample records for twice-a-day trickle irrigation

  1. Review on Trickle Irrigation Application in Groundwater Irrigation Schemes

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    Prastowo

    2006-04-01

    Full Text Available The Government of Indonesia has developed groundwater irrigation schemes in some province e.g. East Java, Central Java, Yogyakarta, Wast Java, Bali, West Nusa Tenggara and East Nusa Tenggara. However, not all regions were able to optimally utilize it. The irrigation effeciency of groundwater irrigation scheme was about 59%, while the wells-pumping efficiencies were varied from 28 to 98 %. In thefuture, the irrigation effieciency should be increased to anticipate water deficit during dry season. The application of trickle irrigation in indonesia has not been widely developed. Although trickle system has been used, however, it is still limited for few commercial agribusinesses. Trickle irrigation systems have a prospect to be developed in some regions having limited water resources. For preliminary stage, the systems could be applied in groundwater irrigation schemes that have been developed either by farmers or government.

  2. Performance analysis of a trickle irrigation subunit installed in an apple orchard

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    Soccol Olívio José

    2002-01-01

    Full Text Available Studies were carried out to evaluate the "xique-xique" irrigation system of a trickle irrigated subunit. Initial results showed that the system's performance was average, any Emission Uniformity, Statistical Uniformity and Coefficient of Global Variation were 74.51, 77.69, and 22.31%, respectively. The efficiency parameters were below expectations, and values of Application Efficiency (Ae, Storage Efficiency (Se, Deep Percolation (Dp, Deficit Degree (DD and Adequacy Degree (a were 100, 47.83, 0, 52.17 and 0% respectively. By adopting new management procedures, it was possible to improve the system's efficiency, reaching values of 90.20, 91.68, 9.80, 8.32 and 52.87% for Ae, Se, Dp, DD and "a", respectively.

  3. Impact of post-infiltration soil aeration at different growth stages of sub-surface trickle-irrigated tomato plants

    Science.gov (United States)

    Li, Yuan; Jia, Zong-xia; Niu, Wen-Quan; Wang, Jing-wei

    2016-07-01

    Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

  4. Twice-a-day fractionated radiotherapy with chemotherapy for locally advanced head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Kumiko; Kojima, Nahoko; Himei, Kengo; Kaneyasu, Yuko; Kita, Midori; Okawa, Tomohiko; Ishii, Tetsuo [Tokyo Women`s Medical Coll. (Japan)

    1998-11-01

    Twenty-nine patients with locally advanced head and neck cancer were treated with twice-a-day fractionated radiotherapy (TDFR) for a total dose of 72 Gy to 82 Gy combined with Neo-adjuvant chemotherapy (NAC) of CDDP+5FU and concurrent chemotherapy of low dose CBDCA between 1994 and 1997. Twenty-one cases (72%) had complete response and sixteen cases recurred. The relapse-free rate at 2 years was 23.4% and the actual 2-year survival rate was 42.0%. No severe toxicity has been observed. Based on this investigation, it was concluded that TDFR with chemotherapy is a promising modality for locally advanced head and neck cancer and toxicity is acceptable. (author)

  5. [A randomized comparative study assessing once versus twice a day treatment of benign prostatic hyperplasia with terazosin].

    Science.gov (United States)

    Suzuki, H; Ohnishi, T; Ikemoto, I; Ohishi, Y; Suzuki, Y; Yamazaki, H

    2001-02-01

    We compared the efficacy of once a day administration of terazosin hydrochloride with that of twice a day administration for benign prostatic hyperplasia (BPH) patients. Forty-two patients with BPH were randomly assigned to receive a maximum dose of 2 mg terazosin either once (n = 21) or twice (n = 21) a day. International prostate symptom score (IPSS), uroflowmetry and side effect profile were determined before and 4 weeks after randomization. Both groups were similar with respect to patient age, baseline IPSS and prostate volume. After 4 weeks of treatment with terazosin, significant improvement in IPSS, maximum flow rate and mean flow rate were observed in both groups. However, these improvements did not differ significantly between them. In addition, there were no differences in side effects between the groups. In conclusion, once a day administration of terazosin hydrochloride is as effective and safe as twice a day administration in patients with BPH.

  6. Quick Trickle Permutation Based on Quick Trickle Characteristic Sequence

    Institute of Scientific and Technical Information of China (English)

    Wang Li-na; Fei Ru-chun; Liu Zhu

    2003-01-01

    The concept of quick trickle characteristic sequence is presented, the properties and count of quick trickle characteristic sequence are researched, the mapping relationship between quick trickle characteristic sequence and quick trickle permutation is discussed. Finally, an efficient construction of quick trickle permutation based on quick trickle characteristic sequence is given, by which quick trickle permutation can be figured out after constructing quick trickle characteristic sequence. Quick trickle permutation has good cryptographic properties.

  7. Avaliação de sistemas de irrigação por gotejamento, utilizados na cafeicultura Evaluation of trickle irrigation systems used in coffee crop

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    Luís O. C. de Souza

    2006-09-01

    Full Text Available Este trabalho foi conduzido no período de agosto a outubro de 1999, com o objetivo de avaliar os sistemas de irrigação por gotejamento utilizados na cafeicultura irrigada do norte do Espírito Santo e nas áreas de cerrado de Minas Gerais e caracterizar a porcentagem de área molhada (PAM nesses sistemas de irrigação. Foram realizadas medidas das dimensões do bulbo molhado para determinação da porcentagem de área molhada. Pelos resultados obtidos verificou-se que, dos valores de coeficiente de uniformidade de distribuição determinados, apenas um sistema apresentou valor abaixo de 70%, refletindo uma uniformidade ruim. No que se refere aos demais resultados, dez sistemas indicaram valores de uniformidade de distribuição entre 70 e 80%, oito sistemas mostraram valores entre 80 e 90% e doze sistemas apontaram valores acima de 90%, indicando uniformidade razoável, boa e excelente, respectivamente. Dos valores determinados, a maioria dos sistemas que apresentaram uniformidade de boa a excelente estava situada na região de cerrado de Minas Gerais. Com relação à PAM, os valores determinados variaram na faixa de 19 a 100% e apenas um sistema apresentou valor abaixo do limite mínimo recomendado para regiões úmidas, que é de 20%.This study was carried out over the period from August to October 1999, aiming the evaluation of trickle irrigation systems used in coffee crop in the northern part of Espírito Santo State and the savannah areas of Minas Gerais State, as well as to characterize the percentage of wetted area (PWA of these irrigation systems. The wetted bulb dimensions measurements were accomplished for determining the percent wetted area. According to the results, just one system presented a value lower than 70% for the distribution uniformity coefficient, reflecting a bad uniformity. Concerning to the other results, ten systems showed the distribution uniformity values ranging from 70 to 80%, whereas for eight systems, it

  8. Exploratory, Phase II Controlled Trial of Shiunko Ointment Local Application Twice a Day for 4 Weeks in Ethiopian Patients with Localized Cutaneous Leishmaniasis

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    Kesara Na-Bangchang

    2016-01-01

    Full Text Available The clinical efficacy and safety of Shiunko ointment (phase II clinical trial was investigated in 40 Ethiopian patients with cutaneous leishmaniasis. Patients were randomized to receive treatment with Shiunko ointment or placebo (n=20, each, applied on the lesion twice a day for 4 weeks. Clinicoparasitological assessments were performed before treatment, weekly for 4 weeks, and then 4, 8, and 12 weeks after the end of treatment. A marked reduction in lesion size was observed on week 16 of treatment in the Shiunko compared with placebo group (69% and 22% reduction, resp.. The overall rate of lesion reduction during the four weeks of treatment was significantly faster in the Shiunko group. Shiunko provided significant effect on wound closure in patients with ulcerated lesion. The clinical efficacy and tolerability of Shiunko were comparable to placebo with regard to its clinicoparasitological response (cure rate and parasitological clearance. Results of this preliminary study may suggest that Shiunko could be useful as adjuvant or as complementary treatment, not as alternatives to current treatment. Its attractive action includes fast lesion healing with a significantly smaller lesion at week 16 of treatment compared with placebo. In addition, its action was promoted in ulcerative lesions.

  9. DISTRIBUIÇÃO DO SISTEMA RADICULAR DA MANGUEIRA SOB IRRIGAÇÃO LOCALIZADA EM SOLO ARENOSO DE TABULEIROS COSTEIROS ROOT DISTRIBUTION OF MANGO UNDER TRICKLE IRRIGATION IN A COAST PLAIN SAND SOIL

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    EUGÊNIO FERREIRA COELHO

    2001-08-01

    Full Text Available O trabalho teve por objetivo avaliar a distribuição de raízes de mangueiras sob irrigação localizada (gotejamento e microaspersão em solo arenoso de Tabuleiros Costeiros. Foram feitas trincheiras a partir do tronco nas direções longitudinal e ortogonal à fileira de plantas e, pelo método do monólito, as raízes puderam ser extraídas do solo e, uma vez separadas, foram digitalizadas com uso de computador e "scanner". Com uso do software Rootedge, foi possível a obtenção dos comprimentos e diâmetros dos segmentos de raízes de todas as amostras, permitindo um mapeamento desses parâmetros nos perfis amostrados. Os resultados mostraram distribuições de raízes assimétricas em relação ao tronco para os dois sistemas de irrigação localizada com possibilidade de maior atividade do sistema radicular para as plantas sob gotejamento (oito gotejadores de 4L.h-1 por planta em relação às plantas sob microaspersão (um emissor por planta de vazão 70L.h-1. Os resultados enfatizaram o uso da fertirrigação como a maneira mais adequada de fertilização em irrigação localizada e permitiram definir regiões do sistema radicular para instalação adequada de sensores de água do solo.The objective of the work was to evaluate root distribution of mango under trickle irrigation (drip and microsprinkler in a Coast Plain Sand Soil. Trenches were dug from the plant trunk longitudinally and orthogonally in respect to row plants. Afterwards, root samples were collected according to the monolith method and separated from the soil. They were scanned and digitized in a PC computer. Root length and diameter were determined by using Rootedge software that allowed to map root distribution on sampled soil profiles. Results showed no simetry of root patterns to the trunk in both irrigation systems. Higher root activity is expected under drip irrigation (eight 4lph-drippers per plant compared to microsprinkler (one 70 lph-emitter per plant. Results

  10. Efeito da qualidade da água na perda de carga em filtros utilizados na irrigação localizada Effect of water quality on head loss in filters utilized in trickle irrigation

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    Túlio A. P. Ribeiro

    2005-03-01

    Full Text Available O presente trabalho teve como objetivo apresentar a investigação experimental de uma fonte hídrica superficial utilizada em um sistema de irrigação por gotejamento e sua influência na evolução da perda de carga de dois filtros, um de disco e outro de manta sintética não-tecida, na filtragem da água. Analisou-se a variação temporal dos principais parâmetros físicos, químicos e biológicos da água de irrigação que causam problemas de entupimento nos emissores. Os critérios para avaliação das impurezas presentes na água de irrigação basearam-se em estudos realizados nos sistemas de irrigação localizada. A pesquisa foi desenvolvida em quatro etapas de 30 dias, em diferentes estações do ano. Os resultados mostraram que os parâmetros químicos que apresentaram médio risco de obstrução aos emissores, foram: pH, ferro e sulfetos. Os parâmetros físicos e biológicos analisados apresentaram baixo risco de entupimento dos emissores. Fez-se o acompanhamento da evolução da perda de carga em função do volume filtrado, objetivando uma análise comparativa. No filtro de manta sintética não-tecida a evolução da perda de carga foi mais acentuada e mais rápida em relação à de disco.This study had the objective to conduct an experimental enquiry on a surface water source utilized in a trickle irrigation system and its influence on the head loss evolution in two filters - a disc filter (130 micra and a non-woven synthetic fabric in filtration of water. The temporal variation of physical, chemical and biological parameters of the irrigation water causing problem of obstruction in drippers were analysed. The evaluation criterion of the impurities present in the irrigation water were based on the studies of the trickle irrigation systems. The research was executed in four phases of 30 days each, in different seasons. The results showed that the chemical factors, which presented medium risk of clogging for emitters, were p

  11. Irrigation Without Waste

    Science.gov (United States)

    Shea, Kevin P.

    1975-01-01

    A new means of irrigation, called the drip or trickle system, has been proven more efficient and less wasteful than the current system of flood irrigation. As a result of this drip system, fertilizer-use efficiency is improved and crop yield, though never decreased, is sometimes increased in some crops. (MA)

  12. Modelagem para o dimensionamento de microtubos em irrigação localizada Modeling for the design of microtubes in trickle irrigation

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    Rodrigo O. R. de M. Souza

    2004-04-01

    Full Text Available Com o intuito de oferecer embasamento técnico-científico para o desenvolvimento de uma irrigação de baixo custo e alto nível tecnológico, este trabalho teve como objetivo desenvolver uma equação para dimensionamento de microtubos em que a perda de carga localizada, a perda de carga ao longo do tubo e a energia de velocidade, estão representados na equação. O presente trabalho foi conduzido no Departamento de Engenharia Rural da ESALQ/USP, onde foi estabelecida, com base nos resultados dos ensaios dos microtubos, a relação entre pressão, comprimento, vazão e diâmetro para três diferentes modelos matemáticos de representação do fenômeno de perda de energia no microtubo. Dentre os modelos propostos, o que considerou a perda de carga localizada nesse fenômeno, com o coeficiente K da equação de perda carga localizada em função do Número de Reynolds (RN foi o que melhor representou o fenômeno de perda de energia no microtubo. Foi testado, também, um modelo que não considera a perda de carga localizada e um outro que ressalta a perda de carga localizada com o coeficiente de perda de carga localizada (K constante. A perda de carga localizada é um importante fator que deve ser considerado no dimensionamento do microtubo. Além disso, em situações de baixo NR o coeficiente de perda de carga localizada (K não é um valor constante e, sim, uma função do NR.The objective of this work was to develop an equation for the design of microtubes where the friction head loss in the microtube wall, the localized head loss and the velocity are explicit in the equation. The aim of this work was to offer a technical base for the development of a high irrigation technology with low cost. The work was carried out at the Rural Engineering Department of the ESALQ/USP. Based on the results of microtube tests the relation between pressure, length, flow and diameter for three different models of microtube head loss were established. The best

  13. Variação dos parâmetros físicos, químicos e biológicos da água em um sistema de irrigação localizada Variation of physical, chemical and biological parameters of water in a trickle irrigation system

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    Túlio A. P. Ribeiro

    2005-09-01

    Full Text Available O presente trabalho teve como objetivo pesquisar, uma fonte hídrica superficial utilizada em um sistema de irrigação por gotejamento, com o fim de se analisar a variação temporal, durante um ano, dos principais parâmetros físicos, químicos e biológicos da sua água e que causam problemas de entupimento nos emissores: sólidos suspensos, turbidez, pH, ferro, sulfetos, condutividade elétrica, sólidos dissolvidos, dureza, índice de Langelier, algas e bactérias Os critérios para avaliação das impurezas presentes na água de irrigação se basearam em estudos realizados por Bucks & Nakayama (1986, no sentido de dar uma orientação de caracter quantitativo que propuseram uma classificação da água, indicando critérios para avaliação do risco de entupimento dos emissores nos sistemas de irrigação localizada. Os resultados mostraram que os parâmetros químicos apresentaram médio risco de obstrução aos emissores, foram pH, ferro e sulfetos, enquanto os parâmetros físicos e biológicos analisados indicaram baixo risco de entupimento dos emissores. Constatou-se correlação dos resultados entre os parâmetros físicos, turbidez e sólidos suspensos totais e o parâmetro biológico algas, com sólidos suspensos totais.This work had the objective to study a superficial water source utilized in a trickle irrigation system. The principal physical, chemical and biological parameters of the irrigation water that caused problems of obstrution in emitters: pH, turbidity, suspensded solids, dissolved solids, EC, hardness, Langelier index, algae and bacterium were analysed during the year. The evaluation criterion of the impurities present in the irrigation water were based on the studies conducted by Bucks & Nakayama (1986, in order to give quantitative orientation of risk of obstruction of drippers in trickle irrigation systems. The chemical factors which showed moderate clogging risk to the emitters were: pH, total iron and sulphite

  14. Estimation of nitrification capacity of rock media trickling filters in ...

    African Journals Online (AJOL)

    Estimation of nitrification capacity of rock media trickling filters in external nitrification BNR. ... process is removed from the BNR activated sludge system and performed eexternallyf on an integrated nitrifying trickling filter (NTF). ... Article Metrics.

  15. Fruit size, mineral composition and quality of trickle-irrigated tomatoes as affected by potassium rates Tamanho, composição mineral e qualidade de frutos de tomateiro irrigado por gotejamento em razão de doses de potássio

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    Paulo Cezar Rezende Fontes

    2000-01-01

    Full Text Available An experiment was conducted to determine the fruit size, mineral composition and quality of trickle-irrigated tomatoes as affected by potassium fertilizer rates. Six potassium (K rates were applied as KCl, corresponding to 0, 48.4, 118.6, 188.8, 259.0 and 399.4 kg ha-1, with four replicates, following a randomized block design. Quadratic responses to K rates were observed for double extra large (diameter > 60 mm, extra large (56 to 60 mm and large (52 to 56 mm fruit yields. Maximum yields of these classes were achieved with K rates of 116, 190 and 233 kg ha-1, respectively. Fruit dry matter, phosphorus, sulfur and magnesium contents were not affected by K rates, but nitrate and K contents showed significant increments as K rates were increased. Vitamin C, total soluble solids, lycopene and beta-carotene contents in the fruits were not affected by K rates. Increments in the K rate lowered the fruit pH and increased total acids content.Para determinar o efeito da fertirrigação com K sobre o tamanho, a composição mineral e a qualidade dos frutos do tomateiro, foi conduzido um experimento com aplicação de seis doses de K, na forma de KCl, correspondendo a 0, 48,4, 118,6, 188,8, 259,0 e 399,4 kg ha-1, com quatro repetições, distribuídas no delineamento experimental em blocos casualizados. Foram observadas respostas quadráticas das produções das classes de frutos graúdo 2 (diâmetro > 60 mm, graúdo 1 (56 a 60 mm e graúdo (52 a 56 mm em relação às doses de K aplicadas na adubação. As produções máximas de frutos de cada classe foram obtidas com as doses de K de 116, 190 e 233 kg ha-1, respectivamente. O conteúdo de matéria seca e os teores de P, S e Mg dos frutos não foram influenciados pelas doses de K, mas os teores de nitrato e de potássio aumentaram com o aumento das doses. Os teores de vitamina C, sólidos solúveis, licopeno e beta-caroteno não foram influenciados pelas doses de K; porém, os incrementos nas doses

  16. Trickling Filters. Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Richwine, Reynold D.

    The textual material for a unit on trickling filters is presented in this student manual. Topic areas discussed include: (1) trickling filter process components (preliminary treatment, media, underdrain system, distribution system, ventilation, and secondary clarifier); (2) operational modes (standard rate filters, high rate filters, roughing…

  17. Trickling filter and trickling filter-suspended growth process design and operation: a state-of-the-art review.

    Science.gov (United States)

    Daigger, Glen T; Boltz, Joshua P

    2011-05-01

    The modern trickling filter typically includes the following major components: (1) rotary distributors with speed control; (2) modular plastic media (typically cross-flow media unless the bioreactor is treating high-strength wastewater, which warrants the use of vertical-flow media); (3) a mechanical aeration system (that consists of air distribution piping and low-pressure fans); (4) influent/recirculation pump station; and (5) covers that aid in the uniform distribution of air and foul air containment (for odor control). Covers may be equipped with sprinklers that can spray in-plant washwater to cool the media during emergency shut down periods. Trickling filter mechanics are poorly understood. Consequently, there is a general lack of mechanistic mathematical models and design approaches, and the design and operation of trickling filter and trickling filter/suspended growth (TF/SG) processes is empirical. Some empirical trickling filter design criteria are described in this paper. Benefits inherent to the trickling filter process (when compared with activated sludge processes) include operational simplicity, resistance to toxic and shock loads, and low energy requirements. However, trickling filters are susceptible to nuisance conditions that are primarily caused by macro fauna. Process mechanical components dedicated to minimizing the accumulation of macro fauna such as filter flies, worms, and snail (shells) are now standard. Unfortunately, information on the selection and design of these process components is fragmented and has been poorly documented. The trickling filter/solids contact process is the most common TF/SG process. This paper summarizes state-of-the art design and operational practice for the modern trickling filter. Water Environ.

  18. Effect of trickle irrigation on root development of the wet bulb and 'pera' orange tree yield in the state of São Paulo, Brazil Efeito da irrigação loclizada no desenvolvimento radicular no bulbo úmido e produção da laranjeira-pera no estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Regina C. de M Pires

    2011-12-01

    Full Text Available The aim of this study was to evaluate the effect of different microirrigation designs on root system distribution in wet bulb region, orange orchard yield and quality of orange fruits. The experiment was installed as random blocks with five treatments and four replicates in an orchard of 'Pêra' orange trees grafted on 'Cleopatra' mandarin rootstock. The treatments consisted of: one drip line (T1, two drip lines (T2, four drip lines (T3 per planting row, microsprinkler irrigation (T4 and without irrigation (T5. Irrigation treatments favored yield and ºBrix. The treatment with a single drip line (T1 showed the greatest quantity of roots in relation to the treatments T2 and T3.O objetivo do presente trabalho foi avaliar o efeito de diferentes configurações da irrigação localizada na distribuição do sistema radicular na região do bulbo úmido, na produção e na qualidade dos frutos de laranjeira. O experimento foi instalado em blocos ao acaso, com cinco tratamentos e quatro repetições, em pomar de plantas adultas de laranjeira-Pera enxertada em tangerina-Cleópatra. Os tratamentos consistiram em parcelas com uma linha de tubogotejador (T1, duas linhas de tubogotejadores (T2, quatro linhas de tubogotejadores (T3 por linha de plantio, microaspersão (T4 e sem irrigação (T5. Os tratamentos irrigados favoreceram a produção e o teor de ºBrix. Observou-se maior concentração de raízes na região do bulbo úmido no T1 em relação ao T2 e ao T3.

  19. Removal characteristics of steroid estrogens in trickling filters

    Institute of Scientific and Technical Information of China (English)

    阳春; 胡碧波; WHEATLEY; Andrew; GLASGOW; Graeme

    2009-01-01

    The discharge of steroid estroens from sewage treatment works (STW) is to be regulated by Environmental Quality Standard in the UK,thus requiring the understanding of removal characteristics of steroid estroens in trickling filters to benefit UK water industry with trickling filters used in 75% STWs. Two pilot-scale trickling filters were operated in parallel to treat synthetic sewage spiked with oestrone (E1),oestradiol (E2) and 17α-ethinyl oestradiol (EE2) at environmentally related concentrations. Control experiments show that biodegradation is the dominant removal mechanism although adsorption onto biofilm solids prior to biodegradation would be part of the overall mechanisms of estrogen removal. Approximately 44.7%-58.9% is removed by the pilot trickling filter normally operated,whilst the 1:1 recirculation increases 29.0%-32.2% estrogen removals by improved wetting rate and hydraulic retention time supported by tracer experiment with lithium chloride. Extra feed solids with 32.0% higher suspended solids levels inhibited estrogen removals by 10.8%-34.4% rather than helping bridge adsorption to the biofilm,and the change of particle characteristics with higher adsorption potency would benefit the removal.

  20. The performance of structured packings in trickle-bed reactors.

    NARCIS (Netherlands)

    Frank, M.J.W.; Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, Geert; van Swaaij, Willibrordus Petrus Maria

    1999-01-01

    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped

  1. The performance of structured packings in trickle-bed reactors.

    NARCIS (Netherlands)

    Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, G.F.; Swaaij, van W.P.M.

    1999-01-01

    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped packi

  2. The Performance of Structured Packings in Trickle-Bed Reactors

    NARCIS (Netherlands)

    Frank, M.J.W.; Kuipers, J.A.M.; Versteeg, G.F.; Swaaij, W.P.M. van

    1999-01-01

    An experimental study was carried out to investigate whether the use of structured packings might improve the mass transfer characteristics and the catalyst effectiveness of a trickle-bed reactor. Therefore, the performances of a structured packing, consisting of KATAPAK elements, and a dumped packi

  3. Transition between trickle flow and pulse flow in a cocurrent gas-liquid trickle-bed reactor at elevated pressures

    NARCIS (Netherlands)

    Wammes, W.J.A.; Mechielsen, S.J.; Westerterp, K.R.

    1992-01-01

    The effect of reactor pressure in the range of 0.2–2.0 MPa on the transition between the trickle-flow and the pulse-flow regime has been investigated for the non-foaming water—nitrogen and aqueous 40% ethyleneglycol—nitrogen systems. Most models and flow charts which are all based on atmospheric

  4. Hydrodynamics in a cocurrent gas-liquid trickle bed at elevated pressures

    NARCIS (Netherlands)

    Wammes, W.J.A.; Middelkamp, J.; Huisman, W.J.; Baas, de C.M.; Westerterp, K.R.

    1991-01-01

    Data on design and operation of trickle beds at elevated pressures are scarce. In this study the influence of the gas density on the liquid holdup, the pressure drop, and the transition between trickle and pulse flow has been investigated in a tricklebed reactor operating up to 7.5 MPa and with nitr

  5. Anaerobic ammonium oxidation in the old trickling filters at Daspooort wastewater treatment works

    CSIR Research Space (South Africa)

    Wilsenach, J

    2014-01-01

    Full Text Available presence of anammox bacteria in the trickling filter biofilm. Genomic DNA was extracted from trickling filter humus sludge and the polymerase chain reaction (PCR) was used to amplify taxonomically informative 16S rRNA gene sequences, using primers specific...

  6. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids

    Directory of Open Access Journals (Sweden)

    Ajay Bansal

    2010-10-01

    Full Text Available Hydrodynamic studies of trickle bed reactors (TBRs are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic liquid saturation are greatly affected by the physical properties of the liquids. In the present study experiments have been carried out in a concurrent downflow air - liquid trickle bed reactor to investigate the dynamic liquid saturation and pressure drop for the water (non-foaming and 3% polyethylene glycol and 4% polyethylene glycol foaming liquids in the gas continuous regime (GCF and foaming pulsing regime (FP. In the GCF regime the dynamic liquid saturation was found to increase with increase in liquid flow rate for non-foaming and foaming liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP regime. The decrease in dynamic liquid saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic liquid saturation was observed. The pressure drop for foaming liquids is observed to be manifolds higher compared to non-foaming liquid in the GCF regime. ©2010 BCREC UNDIP. All rights reserved(Received: 16th January 2010, Revised: 10th February 2010, Accepted: 21st Feberuary 2010[How to Cite: R. Gupta, A. Bansal. (2010. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids. Bulletin of Chemical Reaction Engineering & Catalysis, 5 (1: 31-37. doi:10.9767/bcrec.5.1.775.31-37][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.775.31-37 ][Cited by: Scopus 1 |

  7. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids

    Directory of Open Access Journals (Sweden)

    Renu Gupta

    2010-10-01

    Full Text Available Hydrodynamic studies of trickle bed reactors (TBRs are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic liquid saturation are greatly affected by the physical properties of the liquids. In the present study experiments have been carried out in a concurrent downflow air - liquid trickle bed reactor to investigate the dynamic liquid saturation and pressure drop for the water (non-foaming and 3% polyethylene glycol and 4% polyethylene glycol foaming liquids in the gas continuous regime (GCF and foaming pulsing regime (FP. In the GCF regime the dynamic liquid saturation was found to increase with increase in liquid flow rate for non-foaming and foaming liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP regime. The decrease in dynamic liquid saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic liquid saturation was observed. The pressure drop for foaming liquids is observed to be manifolds higher compared to non-foaming liquid in the GCF regime. ©2010 BCREC UNDIP. All rights reserved(Received: 16th January 2010, Revised: 10th February 2010, Accepted: 21st Feberuary 2010[How to Cite: R. Gupta, A. Bansal. (2010. Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids. Bulletin of Chemical Reaction Engineering & Catalysis, 5 (1: 31-37. doi:10.9767/bcrec.5.1.7127.31-37][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.7127.31-37 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/7127][Cited by: Scopus 1 | ] 

  8. Upgrading Army Sewage Treatment Plant Trickling Filters with Synthetic Media.

    Science.gov (United States)

    1984-08-01

    depth. E. Howland, pp 435-465.o. 1W. W. Eckenfelder , Jr., "Trickling Filter Design and Perforamnce," Jour. San. Engr. Div. ASCE, Vol 87, No. SA4 (July... Eckenfelder 𔃻 suggests 6 = 1.02 to 1.072, in using T-20the equation kT.= k20 6 0 The values of m and n are constant for a given filter, reflecting the type... Eckenfelder , Jr., Industrial Water Pollution Control (McGraw- Hill, 1966). 12Design of Wastewater Treatment Facilities Major Systems, EM 1110-2-501

  9. Styrene biofiltration in a trickle-bed reactor

    Directory of Open Access Journals (Sweden)

    V. Novak

    2008-04-01

    Full Text Available The biological treatment of styrene waste gas in a trickle-bed filter (TBF was investigated. The bioreactor consisted of a two-part glass cylinder (ID 150 mm filled with 25 mm polypropylene Pall rings serving as packing material. The bed height was 1m. Although the laboratory temperature was maintained at 22 ºC, the water temperature in the trickle-bed filter was slightly lower (about 18 ºC.The main aim of our study was to observe the effect of empty-bed residence time (EBRT on bioreactor performance at a constant pollutant concentration over an extended time period. The bioreactor was inoculated with a mixed microbial consortium isolated from a styrene-degrading biofilter that had been running for the previous two years. After three weeks of acclimation period, the bioreactor was loaded with styrene (100 mg.m-3. EBRT was in the range of 53 s to 13 s. A maximum elimination capacity (EC of 11.3 gC.m-3.h-1 was reached at an organic loading (OL rate of 18.6 gC.m-3.h-1.

  10. Irrigation System

    Science.gov (United States)

    1984-01-01

    Under contract with Marshall Space Flight Center, Midwest Research Institute compiled a Lubrication Handbook intended as a reference source for designers and manufacturers of aerospace hardware and crews responsible for maintenance of such equipment. Engineers of Lindsay Manufacturing Company learned of this handbook through NASA Tech Briefs and used it for supplemental information in redesigning gear boxes for their center pivot agricultural irrigation system.

  11. Development of a trickle bed reactor of electro-Fenton process for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yangming [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Hong, E-mail: liuhong@cigit.ac.cn [Key Laboratory of Reservoir Aquatic Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Shen, Zhemin, E-mail: zmshen@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, Wenhua [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2013-10-15

    Highlights: • An electrochemical trickle bed reactor was composed of C-PTFE-coated graphite chips. • The trickle bed reactor had a high H{sub 2}O{sub 2} production rate in a dilute electrolyte. • An azo dye was effectively decomposed by the electro-Fenton process in the reactor. -- Abstract: To avoid electrolyte leakage and gas bubbles in the electro-Fenton (E-Fenton) reactors using a gas diffusion cathode, we developed a trickle bed cathode by coating a layer composed of carbon black and polytetrafluoroethylene (C-PTFE) onto graphite chips instead of carbon cloth. The trickle bed cathode was optimized by single-factor and orthogonal experiments, in which carbon black, PTFE, and a surfactant were considered as the determinant of the performance of graphite chips. In the reactor assembled by the trickle bed cathode, H{sub 2}O{sub 2} was generated with a current of 0.3 A and a current efficiency of 60%. This performance was attributed to the fine distribution of electrolyte and air, as well as the effective oxygen transfer from the gas phase to the electrolyte–cathode interface. In terms of H{sub 2}O{sub 2} generation and current efficiency, the developed trickle bed reactor had a performance comparable to that of the conventional E-Fenton reactor using a gas diffusion cathode. Further, 123 mg L{sup −1} of reactive brilliant red X-3B in aqueous solution was decomposed in the optimized trickle bed reactor as E-Fenton reactor. The decolorization ratio reached 97% within 20 min, and the mineralization reached 87% within 3 h.

  12. Mathematical modeling of a three-phase trickle bed reactor

    Directory of Open Access Journals (Sweden)

    J. D. Silva

    2012-09-01

    Full Text Available The transient behavior in a three-phase trickle bed reactor system (N2/H2O-KCl/activated carbon, 298 K, 1.01 bar was evaluated using a dynamic tracer method. The system operated with liquid and gas phases flowing downward with constant gas flow Q G = 2.50 x 10-6 m³ s-1 and the liquid phase flow (Q L varying in the range from 4.25x10-6 m³ s-1 to 0.50x10-6 m³ s-1. The evolution of the KCl concentration in the aqueous liquid phase was measured at the outlet of the reactor in response to the concentration increase at reactor inlet. A mathematical model was formulated and the solutions of the equations fitted to the measured tracer concentrations. The order of magnitude of the axial dispersion, liquid-solid mass transfer and partial wetting efficiency coefficients were estimated based on a numerical optimization procedure where the initial values of these coefficients, obtained by empirical correlations, were modified by comparing experimental and calculated tracer concentrations. The final optimized values of the coefficients were calculated by the minimization of a quadratic objective function. Three correlations were proposed to estimate the parameters values under the conditions employed. By comparing experimental and predicted tracer concentration step evolutions under different operating conditions the model was validated.

  13. Research on the Aerodynamic Resistance of Trickle Biofilter

    Directory of Open Access Journals (Sweden)

    Alvydas Zagorskis

    2011-12-01

    Full Text Available A four – section trickle biofilter was constructed for experimental research. The filter was filled with the packing material of artificial origin. The material consists of plastic balls having a large surface area. The dependence of biofilter aerodynamic resistance on supply air flow rate and the number of filter sections was determined. The aerodynamic resistance of the biofilter was measured in two cases. In the first case, the packing material of the filter was dry, whereas in the second case it was wet. The experimental research determined that an increase in the air flow rate from 0.043 m/s to 0.076 m/s causes an increase in biofilter aerodynamic resistance from 30.5 to 62.5 Pa after measuring four layers of dry packing material. In case of wet packing material, biofilter aerodynamic resistance after measuring four layers of plastic balls increases from 42.1 to 90.4 Pa.Article in Lithuanian

  14. Biofiltration of Chloroform in a Trickle Bed Air Biofilter Under ...

    Science.gov (United States)

    In this paper, the application of biofiltration is investigated for controlled removal of gas phase chloroform through cometabolic degradation with ethanol. A trickle bed air biofilter (TBAB) operated under acidic pH 4 is subjected to aerobic biodegradation of chloroform and ethanol. The TBAB is composed of pelleted diatomaceous earth filter media inoculated with filamentous fungi species, which served as the principle biodegrading microorganism. The removal efficiencies of 5 ppmv of chloroform mixed with different ratios of ethanol as cometabolite (25, 50, 100, 150, and 200 ppmv) ranged between 69.9 and 80.9%. The removal efficiency, reaction rate kinetics, and the elimination capacity increased proportionately with an increase in the cometabolite concentration. The carbon recovery from the TBAB amounted to 69.6% of the total carbon input. It is postulated that the remaining carbon contributed to excess biomass yield within the system. Biomass control strategies such as starvation and stagnation were employed at different phases of the experiment. The chloroform removal kinetics provided a maximum reaction rate constant of 0.0018 s−1. The highest ratio of chemical oxygen demand (COD)removal/nitrogenutilization was observed at 14.5. This study provides significant evidence that the biodegradation of a highly chlorinated methane can be favored by cometabolism in a fungi-based TBAB. Chloroform is volatile hazardous chemical emitted from publicly owned treatment

  15. Development of a trickle bed reactor of electro-Fenton process for wastewater treatment.

    Science.gov (United States)

    Lei, Yangming; Liu, Hong; Shen, Zhemin; Wang, Wenhua

    2013-10-15

    To avoid electrolyte leakage and gas bubbles in the electro-Fenton (E-Fenton) reactors using a gas diffusion cathode, we developed a trickle bed cathode by coating a layer composed of carbon black and polytetrafluoroethylene (C-PTFE) onto graphite chips instead of carbon cloth. The trickle bed cathode was optimized by single-factor and orthogonal experiments, in which carbon black, PTFE, and a surfactant were considered as the determinant of the performance of graphite chips. In the reactor assembled by the trickle bed cathode, H2O2 was generated with a current of 0.3A and a current efficiency of 60%. This performance was attributed to the fine distribution of electrolyte and air, as well as the effective oxygen transfer from the gas phase to the electrolyte-cathode interface. In terms of H2O2 generation and current efficiency, the developed trickle bed reactor had a performance comparable to that of the conventional E-Fenton reactor using a gas diffusion cathode. Further, 123 mg L(-1) of reactive brilliant red X-3B in aqueous solution was decomposed in the optimized trickle bed reactor as E-Fenton reactor. The decolorization ratio reached 97% within 20 min, and the mineralization reached 87% within 3h.

  16. Effect of scattered feeding and feeding twice a day during rearing on indicators of hunger and frustration in broiler breeders

    NARCIS (Netherlands)

    Jong, de I.C.; Wolthuis-Fillerup, M.; Blokhuis, H.J.

    2005-01-01

    Broiler breeders are routinely fed restricted during rearing which has a major negative effect on their welfare. They suffer from hunger and frustration from thwarting of feeding. The aim of this experiment was therefore to study if broiler breeder welfare can be improved by changes in the feeding s

  17. Study on hydrogen sulfide removal based on bench-scale experiment by bio-trickling filter

    Institute of Scientific and Technical Information of China (English)

    TIAN Shu-lei; ZHANG Lan-he; WANG Qun-hui; WANG Xu-ming; XIE Wei-min

    2007-01-01

    A bench-scale experiment for control of hydrogen sulfide (H2S) emissions was carried out continuously for nearly four months by using bio-trickling filter packed with ZX01 stuffing. The results suggested that the bio-trickling filter had proven excellent performance over substantial operational periods. Removal efficiency of H2S was nearly 100% when volumetric loading of the bio-trickling filter varied from 0.64 g/(m3·h)to 38.20 g/(m3·h) and metabolism products of H2S were mainly composed of SO42-. When inlet concentration of H2S was 250 mg/m3, the optimum gas retention time was 30 s and the optimum spray water not blocked during experiments for nearly four months during which resistance was maintained at relatively lower value, so that the bio-trickling filter need not carry out back washing frequently and can be operated steadily for long-term.

  18. Hydrodynamic behaviour of a gas—solid counter-current packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; Swaaij, van W.P.M.

    1979-01-01

    Trickle flow of a more or less fluidized catalyst through a packed column is a promising new gas—solid counter-current operation. The hydrodynamic, behaviour of such a column, filled with dumped PALL rings, has been investigated, while some results have been obtained with RASCHIG rings and cylindric

  19. Methanol synthesis in a countercurrent gas-solid-solid trickle flow reactor. An experimental study

    NARCIS (Netherlands)

    Kuczynski, M.; Oyevaar, M.H.; Pieters, R.T.; Westerterp, K.R.

    1987-01-01

    The synthesis of methanol from CO and H2 was executed in a gas-solid-solid trickle flow reactor. The reactor consisted of three tubular reactor sections with cooling sections in between. The catalyst was Cu on alumina, the adsorbent was a silica-alumina powder and the experimental range 498–523 K,

  20. CO2 capture in a continuous gas–solid trickle flow reactor

    NARCIS (Netherlands)

    Veneman, Rens; Hilbers, T.J.; Brilman, Derk Willem Frederik; Kersten, Sascha R.A.

    2016-01-01

    This paper describes the selection, design and experimental validation of a gas–solid trickle flow adsorber for post-combustion CO2 capture using a supported amine sorbents (Lewatit® VP OC 1065). The experimental work presented here summarizes over 300 h of operating experience, which is equivalent

  1. The heat-transfer performance of gas—solid trickle flow over a regularly stacked packing

    NARCIS (Netherlands)

    Verver, A.B.; Swaaij, van W.P.M.

    1986-01-01

    The heat-transfer behaviour of a countercurrent gas—solid trickle flow contactor is studied, using coarse sand particles as the solids phase. Experimental data on the overall heat-transfer rate constant between the gas flow and the solid particle flow were obtained in a 0.15 m square cross-section c

  2. Biofiltration of Chloroform in a Trickle Bed Air Biofilter Under Acidic Conditions

    Science.gov (United States)

    In this paper, the application of biofiltration is investigated for controlled removal of gas phase chloroform through cometabolic degradation with ethanol. A trickle bed air biofilter (TBAB) operated under acidic pH 4 is subjected to aerobic biodegradation of chloroform and etha...

  3. Design and performance of a trickling air biofilter for chlorobenzene and o-dichlorobenzene vapors.

    Science.gov (United States)

    Oh, Y S; Bartha, R

    1994-01-01

    From contaminated industrial sludge, two stable multistrain microbial enrichments (consortia) that were capable of rapidly utilizing chlorobenzene and o-dichlorobenzene, respectively, were obtained. These consortia were characterized as to their species composition, tolerance range, and activity maxima in order to establish and maintain the required operational parameters during their use in biofilters for the removal of chlorobenzene contaminants from air. The consortia were immobilized on a porous perlite support packed into filter columns. Metered airstreams containing the contaminant vapors were partially humidified and passed through these columns. The vapor concentrations prior to and after biofiltration were measured by gas chromatography. Liquid was circulated concurrently with the air, and the device was operated in the trickling air biofilter mode. The experimental arrangement allowed the independent variation of liquid flow, airflow, and solvent vapor concentrations. Bench-scale trickling air biofilters removed monochlorobenzene, o-dichlorobenzene, and their mixtures at rates of up to 300 g of solvent vapor h(-1) m(-3) filter volume. High liquid recirculation rates and automated pH control were critical for stable filtration performance. When the accumulating NaCl was periodically diluted, the trickling air biofilters continued to remove chlorobenzenes for several months with no loss of activity. The demonstrated high performance and stability of the described trickling air biofilters favor their use in industrial-scale air pollution control. PMID:8085815

  4. EVALUATION OF TRICKLE-BED AIR BIOFILTER PERFORMANCE FOR STYRENE REMOVAL

    Science.gov (United States)

    A pilot-scale trickle-bed air biofilter (TBAB) was evaluated for the removal of styrene from a waste gas stream. Six-millimeter (6 mm) Celite pellets (R-635) were used as the biological attachment medium. The operating parameters considered in the study included the styrene vol...

  5. Continuous biological waste gas treatment in stirred trickle-bed reactor with discontinuous removal of biomass.

    Science.gov (United States)

    Laurenzis, A; Heits, H; Wübker, S; Heinze, U; Friedrich, C; Werner, U

    1998-02-20

    A new reactor for biological waste gas treatment was developed to eliminate continuous solvents from waste gases. A trickle-bed reactor was chosen with discontinuous movement of the packed bed and intermittent percolation. The reactor was operated with toluene as the solvent and an optimum average biomass concentration of between 5 and 30 kg dry cell weight per cubic meter packed bed (m3pb). This biomass concentration resulted in a high volumetric degradation rate. Reduction of surplus biomass by stirring and trickling caused a prolonged service life and prevented clogging of the trickle bed and a pressure drop increase. The pressure drop after biomass reduction was almost identical to the theoretical pressure drop as calculated for the irregular packed bed without biomass. The reduction in biomass and intermittent percolation of mineral medium resulted in high volumetric degradation rates of about 100 g of toluene m-3pb h-1 at a load of 150 g of toluene m-3pb h-1. Such a removal rate with a trickle-bed reactor was not reported before.

  6. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  7. Irrigation and Autocracy

    DEFF Research Database (Denmark)

    Bentzen, Jeanet Sinding; Kaarsen, Nicolai; Wingender, Asger Moll

    We show that societies with a history of irrigation-based agriculture have been less likely to adopt democracy than societies with a history of rainfed agriculture. Rather than actual irrigation, the empirical analysis is based on how much irrigation potentially can increase yields.Irrigation...

  8. Biological treatment of wastewaters from a dye manufacturing company using a trickling filter

    Energy Technology Data Exchange (ETDEWEB)

    Kornaros, M. [Department of Chemical Engineering, University of Patras, 1 Karatheodori St., 26500 Patras (Greece)]. E-mail: kornaros@chemeng.upatras.gr; Lyberatos, G. [Department of Chemical Engineering, University of Patras, 1 Karatheodori St., 26500 Patras (Greece)

    2006-08-10

    The aim of this work was to assess the effectiveness of a biological trickling filter for the treatment of wastewaters produced by a company manufacturing organic dyes and varnishes. The combined wastewater effluent was fed to a pilot-scale trickling filter in two feeding modes, continuously and as a sequencing batch reactor (SBR). The biodegradability of the diluted wastewaters that were subjected to physicochemical treatment, using Ca(OH){sub 2} and FeSO{sub 4}, was initially studied using a continuously operated trickling filter. The system efficiency ranged up to 60-70% for a hydraulic loading of 1.1 m{sup 3}/m{sup 2} day and up to 80-85% for a hydraulic loading 0.6 m{sup 3}/m{sup 2} day. A stable chemical oxygen demand (COD) removal efficiency of 60-70% was achieved even in the case of undiluted wastewater at a hydraulic loading of 1.1 m{sup 3}/m{sup 2} day. The effectiveness of biological treatment of a mixture of the company's main wastewater streams was also examined. The microorganisms developed in the trickling filter were able to efficiently remove COD levels up to 36,000 mg/L, under aerobic conditions at pH values between 5.5 and 8.0. Depending on the operating conditions of the system, about 30-60% of the total COD removal was attributed to air stripping caused by the air supply at the bottom of the filter, whereas the rest of the COD was clearly removed through biological action. The proposed biological treatment process based on a trickling filter, which was operated either continuously or even better in an SBR mode, appears as a promising pretreatment step for coping with dye manufacturing wastewaters in terms of removing a significant portion of the organic content.

  9. Performance evaluation of integrated treatment plant of trickling filter and constructed wetland

    Directory of Open Access Journals (Sweden)

    Harikumar P.S

    2011-01-01

    Full Text Available A system consisting of trickling filter followed by a vertical intermittent flow constructed wetland system under laboratory condition was evaluated for the treatment of domestic wastewater. The system was able to produce final effluents with low concentrations of both organic and nutrients. Mean effluent concentrations were,respectively: BOD: 22.22mg/L;COD:64.58mg/L;SS:27.63mg/L;NH4-N:0.62mg/L;P:1.72mg/L. The study shows that the integrated treatment system of trickling filter and vertical intermittent flow constructed wetlands can be effectively used a treatment option for a treatment with positive attributes of conceptual simplicity and lesser energy consumption.

  10. Adopting primary plastic trickling filters as a solution for enhanced nitrification.

    Science.gov (United States)

    Wilson, Simon P; Ouki, Sabeha K; Saroj, Devendra P; Pearce, Pete A; Bancroft, Louise; Germain, Eve

    2015-01-01

    The wastewater industry is under pressure to optimize performance of sewage treatment works (STW), while simultaneously reducing energy consumption. Using a process configuration selection matrix, this paper explores the practicability of placing a hypothetical cross flow structured plastic media (CFSP) trickling filter (TF) immediately ahead of an existing conventional trickling filter process (CTFP), without intermediate clarification. The viability of this configuration is subsequently demonstrated using an empirical multispecies TF model. This predicts the enhanced nitrification performance of the CTFP by simulating prior removals of biochemical oxygen demand (BOD). The model predictions propose that prior 50-80% BOD removals can allow for further reductions in effluent ammoniacal nitrogen (NH4-N) concentrations of 40-70%, respectively. This illustrates that adopting low energy TF technologies can eliminate the requirement for more energy intensive alternatives, such as submerged aerated filters (SAF). Moreover, this configuration maximizes the potential of existing assets, while simultaneously improving nitrification robustness when compared with tertiary nitrification processes.

  11. Integrated coagulation-trickling filter-ultrafiltration processes for domestic wastewater treatment and reclamation.

    Science.gov (United States)

    Zhao, Qing-Liang; Zhong, Hui-Yuan; Liu, Jin-Li; Liu, Yu

    2012-01-01

    More and more research effort has been put into the development of affordable and high-efficiency wastewater reclamation technology for small communities. In this study, an integrated chemically enhanced primary treatment (CEPT), trickling filter (TF) and ultrafiltration (UF) process was developed with success. Coagulant produced from fly ash was used to enhance primary treatment, while trickling filter packed with coal cinder through four-layer structure without aeration was employed for further removal of COD and ammonium-nitrogen from the CEPT effluent. 95 and 88% removal of COD and ammonium were achieved, while total phosphorus (TP) and suspended solid (SS) were found to be removed completely at a coagulant dosage of 2.5 mL/L in the CEPT-TF-UF system. The product water can meet the standard of Reuse of Recycling Water for Urban Water Quality Standard for Urban Miscellaneous Water Consumption (GB/T 18920-2002, China).

  12. Ghana - Agriculture - Irrigation

    Data.gov (United States)

    Millennium Challenge Corporation — The Millennium Development Authority (MiDA) financed the construction of a new irrigation scheme in Kpong and the renovation of two irrigation schemes in Botanga and...

  13. Theoretical model for removal of volatile organic compound (VOC) air pollutant in trickling biofilter

    Institute of Scientific and Technical Information of China (English)

    LIAO; Qiang; (廖; 强); CHEN; Rong; (陈; 蓉); ZHU; Xun; (朱; 恂)

    2003-01-01

    This paper presents an analytical model for predicting VOC waste gas degradation in a trickling biofilter. To facilitate the analysis, the packed bed is simplified into a series of straight capillary tubes covered by the biofilm. The gas-liquid flow field through the tube is divided into the liquid film flow on the biofilm and the gas core flow in the center. The biofilm consists of a reaction free zone close to solid wall and a reaction zone beneath the liquid film. The capillary tube model accounts for the effect of mass transport resistance in the liquid film and the biofilm, the gas-liquid interfacial mass transport resistance, the biochemical reaction, and the limitation of oxygen to biochemical reaction. The liquid film thickness in the capillary tube is obtained by simultaneously solving a set of hydrodynamic equations representing the momentum transport behaviors of the gas-liquid two-phase flow. The mass transport equations are established for gas core, liquid film, and biofilm combined with biochemical kinetics equations. An iterative computation process is employed to solve the discrete equations. The predicted purification efficiencies of VOC waste gas in trickling biofilter are found to be in good agreement with the experimental data. It has been revealed that for a fixed inlet concentration of toluene, the purification efficiency of trickling biofilter decreases with the increase in gas flow rate and liquid flow rate. The purification efficiency of VOC waste gas is dominated by mass transport resistance in liquid film and biofilm. The highest biodegradation rate occurs at the inlet of waste gas in trickling biofilter.

  14. Modeling of a trickling bioreactor for the simultaneous removal of hydrogen sulfide and carbon disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, R.; Viveros-Garcia, T.; Revah, S. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico)

    1996-12-31

    A model is presented for a trickle biofilm reactor based on liquid falling film hydrodynamics and linear residence times. It is shown that mass transfer resistance is high. Performance of pseudo homogeneous and heterogeneous models is discussed. It is shown that the use of superficial residence times reduces the heterogeneous model to a pseudo homogeneous one and masks parametric response. 8 refs., 2 figs., 1 tab.

  15. Intermittent trickling bed filter for the removal of methyl ethyl ketone and methyl isobutyl ketone.

    Science.gov (United States)

    Farnazo, Danvir Mark C; Nisola, Grace M; Han, Mideok; Yoo, Namjong; Chung, Wook-Jin

    2012-05-01

    Biodegradations of methyl ethyl ketone and methyl isobutyl ketone were performed in intermittent biotrickling filter beds (ITBF) operated at two different trickling periods: 12 h/day (ITBF-12) and 30 min/day (ITBF-0.5). Ralstonia sp. MG1 was able to degrade both ketones as evidenced by growth kinetic experiments. Results show that trickling period is an important parameter to achieve high removal performance and to maintain the robustness of Ralstonia sp. MG1. Overall, ITBF-12 outperformed ITBF-0.5 regardless of the target compound. ITBF-12 had high performance recovery at various inlet gas concentrations. The higher carbon dioxide production rates in ITBF-12 suggest higher microbial activity than in ITBF-0.5. Additionally, lower concentrations of absorbed volatile organic compound (VOC) in trickling solutions of ITBF-12 systems also indicate VOC removal through biodegradation. Pressure drop levels in ITBF-12 were relatively higher than in ITBF-0.5 systems, which can be attributed to the decrease in packed bed porosity as Ralstonia sp. MG1 grew well in ITBF-12. Nonetheless, the obtained pressure drop levels did not have any adverse effect on the performance of ITBF-12. Biokinetic constants were also obtained which indicated that ITBF-12 performed better than ITBF-0.5 and other conventional biotrickling filter systems.

  16. APPLICATION OF TRICKLING FILTER FOR SEWAGE TREATMENT WITH HIGH AMMONIA NITRO GEN CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Wojciech Dąbrowski

    2016-05-01

    Full Text Available The article presents the results of research about the possibility of using trickling filter for high ammonia concentration sewage treatment. The study was conducted with the use of reject water generated during anaerobic sewage sludge stabilization in dairy wastewater treatment plant (WWTP. They are usually returned to the beginning of WWTP. The value of BOD in reject water was approximately the same as in domestic and municipal sewage. Ammonia nitrogen concentration was varied from 145,0 to 390,0 mgN-NH4+/l and phosphorus from 16.0 to 38.0 mgP/l. The study used the Gunt test system CE701e, which allows controlling basic parameters of the treatment with trickling filter. Significant reduction of organic matter, total nitrogen and ammonium was observed during treatment. Average removal efficiency of ammonia nitrogen ranged from 73.6 to 80.3%. In the case of the Kjeldahl nitrogen removal efficiencies ranged from 74.4 to 79.8%. Because of the aerobic conditions during the treatment of phosphorus removal efficiency was low and varied from 32.0 to 33.7%. The research confirmed the efficiency of trickling filter for treatment sewage with high concentration of ammonia nitrogen.

  17. WATER REQUIREMENT OF IRRIGATED GARLIC

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  18. Water Requirements Of Irrigated Garlic

    Science.gov (United States)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  19. Root canal irrigants.

    Science.gov (United States)

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-10-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were 'root canal irrigants' and 'endodontic irrigants.' The reference lists of each article were manually checked for additional articles of relevance.

  20. Trickling filter for urea and bio-waste processing - dynamic modelling of nitrogen cycle

    Science.gov (United States)

    Zhukov, Anton; Hauslage, Jens; Tertilt, Gerin; Bornemann, Gerhild

    Mankind’s exploration of the solar system requires reliable Life Support Systems (LSS) enabling long duration manned space missions. In the absence of frequent resupply missions, closure of the LSS will play a very important role and its maximisation will to a large extent drive the selection of appropriate LSS architectures. One of the significant issues on the way to full closure is to effectively utilise biological wastes such as urine, inedible biomass etc. A very promising concept of biological waste reprocessing is the use of trickling filters which are currently being developed and investigated by DLR, Cologne, Germany. The concept is called Combined Regenerative Organic-Food Production (C.R.O.P.) and is based on the microbiological treatment of biological wastes and reprocessing them into aqueous fertilizer which can directly be used in a greenhouse for food production. Numerous experiments have been and are being conducted by DLR in order to fully understand and characterize the process. The human space exploration group of the Technical University of Munich (TUM) in cooperation with DLR has started to establish a dynamic model of the trickling filter system to be able to assess its performance on the LSS level. In the first development stage the model covers the nitrogen cycle enabling to simulate urine processing. This paper describes briefly the C.R.O.P. concept and the status of the trickling filter model development. The model is based on enzyme-catalyzed reaction kinetics for the fundamental microbiological reaction chain and is created in MATLAB. Verification and correlation of the developed model with experiment results has been performed. Several predictive studies for batch sequencing behavior have been performed, demonstrating a good capability of C.R.O.P. concept to be used in closed LSS. Achieved results are critically discussed and way forward is presented.

  1. Intensification of Deep Hydrodesulfurization Through a Two-stage Combination of Monolith and Trickle Bed Reactors

    Institute of Scientific and Technical Information of China (English)

    Min Xu; Hui Liu⁎; Shengfu Ji; Chengyue Li

    2014-01-01

    Deep hydrodesulfurization (HDS) is an important process to produce high quality liquid fuels with ultra-low sul-fur. Process intensification for deep HDS could be implemented by developing new active catalysts and/or new types of reactors. In this work, the kinetics of dibenzothiophene (DBT) hydrodesulfurization over Ni-P/SBA-15/cordierite catalyst was investigated at 340-380 °C and 3.0-5.0 MPa. The first-order reaction model with respect to both DBT and H2 was used to fit the kinetics data in a batch recycle operation system. It is found that both the activation energy and rate constant over the Ni-P monolithic catalyst under our operating conditions are close to those over conventionally used HDS catalysts. Comparative performance studies of two types of reactors, i.e., trickle bed reactor and monolithic reactor, were performed based on reactor modeling and simulation. The results indicate that the productivity of the monolithic reactor is 3 times higher than that of the trickle bed reactor on a catalyst weight basis since effective utilization of the catalyst is higher in the monolithic reactor, but the volumetric productivity of the monolithic reactor is lower for HDS of DBT. Based on simulation results, a two-reactor-in-series configuration for hydrodesulfurization is proposed, in which a monolithic reactor is followed by a tickled bed reactor so as to attain intensified performance of the system converting fuel oil of different sulfur-containing compounds. It is il ustrated that the two reactor scheme outperforms the trickle bed reactor both on reactor volume and catalyst mass bases while the content of sulfur is reduced from 200μg·g-1 to about 10μg·g-1.

  2. Trickle/pulse flow regime transition in downflow packed tower involving foaming liquids

    Directory of Open Access Journals (Sweden)

    Sodhi Vijay

    2012-01-01

    Full Text Available The most of past studies in foaming trickle bed reactors aimed at the improvement of efficiency and operational parameters leads to high economic advantages. Conventionally most of the industries rely on frequently used gas continuous flow (GCF where operational output is satisfactory but not yields efficiently as in pulsing flow (PF and foaming pulsing flow (FPF. Hydrodynamic characteristics like regime transitions are significantly influenced by foaming nature of liquid as well as gas and liquid flow rates. This study’s aim was to demonstrate experimentally the effects of liquid flow rate, gas flow rates and liquid surface tension on regime transition. These parameters were analyzed for the air-aqueous Sodium Lauryl Sulphate and air-water systems. More than 240 experiments were done to obtain the transition boundary for trickle flow (GCF to foaming pulsing flow (PF/FPF by use excessive foaming 15-60 ppm surfactant compositions. The trickle to pulse flow transition appeared at lower gas and liquid flow rates with decrease in liquid surface tension. All experimental data had been collected and drawn in the form of four different transitional plots which are compared and drawn by using flow coordinates proposed by different researchers. A prominent decrease in dynamic liquid saturation was observed especially during regime transitional change. The reactor two phase pressure evident a sharp rise to verify the regime transition shift from GCF to PF/FPF. Present study reveals, the regime transition boundary significantly influenced by any change in hydrodynamic as well as physiochemical properties including surface tension.

  3. Armenia - Irrigation Infrastructure

    Data.gov (United States)

    Millennium Challenge Corporation — This study evaluates irrigation infrastructure rehabilitation in Armenia. The study separately examines the impacts of tertiary canals and other large infrastructure...

  4. Periodic Packing Mode for Trickle-Bed Reactors:Experiments and Modeling

    Institute of Scientific and Technical Information of China (English)

    刘国柱; 米镇涛

    2004-01-01

    A periodic packing mode of trickle-bed reactor (TBR) for the gas limited reaction was proposed. Hydrogenation of 2-ethylanthraquinone over Pd/A12Oa in a laboratory-scale TBR was taken as a test reaction for determining whether the periodic packing mode is advantageous. The effects of operating conditions and packing type on TBR performance were experimentally examined to demonstrate the cause-effect relationships. A mathematic model of TBR considering axial dispersion and fractional wetting was developed to quantitatively illuminate the reason of performance enhancement.

  5. Irrigation water quality assessments

    Science.gov (United States)

    Increasing demands on fresh water supplies by municipal and industrial users means decreased fresh water availability for irrigated agriculture in semi arid and arid regions. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require co...

  6. Irrigation Systems. Student's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by individuals preparing for a career in commercial and residential irrigation. The materials included are geared toward students who have had some experience in the irrigation business; they are intended to be presented in 10 six-hour sessions. The first two sections deal with using this guide and preparing for the…

  7. Irrigation Systems. Instructor's Guide.

    Science.gov (United States)

    Amarillo Coll., TX.

    This guide is intended for use by licensed irrigators who wish to teach others how to design and install residential and commercial irrigation systems. The materials included in the guide have been developed under the assumption that the instructors who use it have little or no formal training as teachers. The first section presents detailed…

  8. Performance and microbial diversity of aerated trickling biofilter used for treating cheese industry wastewater.

    Science.gov (United States)

    Saminathan, Sumathi K M; Galvez-Cloutier, Rosa; Kamal, Najat

    2013-05-01

    Wastewater discharged from cheese industries is often characterized by high values of organic pollutants, solids, and nutrients. An aerated trickling biofilter using peat and perlite as filter media was employed in a pilot-scale level in order to evaluate the performance of biofilter for removal of pollutants from cheese industry wastewater. The biofilter was operated for a period of 33 days under laboratory conditions, and several parameters were monitored. The results showed a significant improvement in the quality of treated effluent. The maximum removal efficiencies of chemical oxygen demand and biological oxygen demand were 99.2 and 99.9 %, respectively. Significant reduction in total suspended solids (>96 %) was also achieved. A stable ammoniacal-nitrogen (NH(4)-N) removal was accompanied by biofilter. On an average, NH(4)-N and total nitrogen decreased by 98.7 and 72 %, respectively, with a significant portion of NH(4)-N being converted to nitrate-nitrogen (NO(3)-N). Also, a molecular approach based on 16S rDNA was employed to analyze the bacterial community composition present in the biofilter. A comparative sequence analysis of excised denaturing gradient gel electrophoresis bands revealed the presence of diverse groups of bacteria belonging to α- and β-Proteobacteria and Bacteroidetes phylum. We conclude from the results that the use of trickling biofilter is highly effective and a potential treatment method for polishing cheese industry wastewater before being discharged into the local environment.

  9. Trickle-Charge: a New Operational Mode for PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Kozanecki, W.; /DSM, DAPNIA, Saclay; Colocho, W.S.; Decker, F.-J.; Ecklund, S.; Fisher, A.S.; Iverson, R.H.; O' Grady, C.; Seeman, J.; Sullivan, M.K.; Turner, J.L.; Weaver,; Wienands, U.; /SLAC

    2005-05-09

    In regular top-up-and-coast operation, PEP-II average luminosity is about 70-75% of the peak luminosity due to detector ramp-down and ramp-up times plus the time it takes to top-up both beams. We recently commissioned a new operational mode where the Low Energy Ring is injected continuously without ramping down the detector. The benefits--increased luminosity lifetime and roughly half the number of top-ups per shift--were expected to give an increase in delivered luminosity of about 15% at the same peak luminosity; this was confirmed in test runs. In routine trickle operation, however, it appears that the increase in delivered luminosity is more than twice that due to an increase in availability credited to the more stable operating conditions during trickle operation. Further gains were made when continuous injection was extended to the high energy ring as well. In this paper we will present our operational experience as well as some of the diagnostics we use to monitor and maintain tuning of the machine in order to control injection background and protect the detector.

  10. A model for a countercurrent gas—solid—solid trickle flow reactor for equilibrium reactions. The methanol synthesis

    NARCIS (Netherlands)

    Westerterp, K.R.; Kuczynski, M.

    1987-01-01

    The theoretical background for a novel, countercurrent gas—solid—solid trickle flow reactor for equilibrium gas reactions is presented. A one-dimensional, steady-state reactor model is developed. The influence of the various process parameters on the reactor performance is discussed. The physical

  11. Performance and population analysis of a non-sterile trickle bed reactor inoculated with caldicellulosiruptor saccharolyticus, a thermophilic hydrogen producer

    NARCIS (Netherlands)

    Groenestijn, J.W. van; Geelhoed, J.S.; Goorissen, H.P.; Meesters, K.P.M.; Stams, A.J.M.; Claassen, P.A.M.

    2009-01-01

    Non-axenic operation of a 400 L trickle bed reactor inoculated with the thermophile Caldicellulosiruptor saccharolyticus, yielded 2.8 molH 2mol hexose converted. The reactor was fed with a complex medium with sucrose as the main substrate, continuously flushed with nitrogen gas, and operated at 73°C

  12. Irrigation in endodontics.

    Science.gov (United States)

    Haapasalo, M; Shen, Y; Wang, Z; Gao, Y

    2014-03-01

    Irrigation is a key part of successful root canal treatment. It has several important functions, which may vary according to the irrigant used: it reduces friction between the instrument and dentine, improves the cutting effectiveness of the files, dissolves tissue, cools the file and tooth, and furthermore, it has a washing effect and an antimicrobial/antibiofilm effect. Irrigation is also the only way to impact those areas of the root canal wall not touched by mechanical instrumentation. Sodium hypochlorite is the main irrigating solution used to dissolve organic matter and kill microbes effectively. High concentration sodium hypochlorite (NaOCl) has a better effect than 1 and 2% solutions. Ethylenediaminetetraacetic acid (EDTA) is needed as a final rinse to remove the smear layer. Sterile water or saline may be used between these two main irrigants, however, they must not be the only solutions used. The apical root canal imposes a special challenge to irrigation as the balance between safety and effectiveness is particularly important in this area. Different means of delivery are used for root canal irrigation, from traditional syringe-needle delivery to various machine-driven systems, including automatic pumps and sonic or ultrasonic energy.

  13. Efficiency of a locally designed pilot-scale trickling biofilter (TBF) system in natural environment for the treatment of domestic wastewater.

    Science.gov (United States)

    Rasool, Tabassum; Rehman, Abdul; Naz, Iffat; Ullah, Rahat; Ahmed, Safia

    2017-06-07

    In the present study, a cost-effective and simple stone media pilot-scale trickling biofilter (TBF) was designed, constructed and operated in a continuous recirculation mode for wastewater treatment with a hydraulic flow rate of 1.2 L/min (Q = 0.072 m(3)/h) and hydraulic loading (Q/A) of 0.147 m(3)/day for 15 weeks at a temperature range of 14.5-36°C. A substantial reduction in the average concentration of different pollution indicators, such as chemical oxygen demand (COD) (85.6%), biochemical oxygen demand (BOD5) (85.6%), total dissolved solid (TDS) (62.8%), total suspended solid (TSS) (99.9%), electrical conductivity (EC) (15.1%), phosphates (63.22%), sulfates (28.5%) and total nitrogen (TN) (34.4%), was observed during 15 weeks of operational period. Whereas a considerable average increase in the levels of dissolved oxygen (DO) (63.2%) was found after treatment of wastewater by the TBF system. No significant reduction in most probable number (MPN) index of fecal coliforms was observed in the effluent in first 9 weeks of operation. However, a significant reduction in the MPN of fecal coliforms was observed, i.e. 80-90% in the last few weeks of treatment. Thus, overall results suggest that pilot-scale TBF has a great potential to be transferred to field scale for treating sewage for small communities in developing countries, in order to produce effluent of good quality, which can be safely used for irrigation as well as ornamental purposes.

  14. Acetone-butanol-ethanol (ABE) fermentation in an immobilized cell trickle bed reactor.

    Science.gov (United States)

    Park, C H; Okos, M R; Wankat, P C

    1989-06-05

    Acetone-butanol-ethanol (ABE) fermentation was successfully carried out in an immobilized cell trickle bed reactor. The reactor was composed of two serial columns packed with Clostridium acetobutylicum ATCC 824 entrapped on the surface of natural sponge segments at a cell loading in the range of 2.03-5.56 g dry cells/g sponge. The average cell loading was 3.58 g dry cells/g sponge. Batch experiments indicated that a critical pH above 4.2 is necessary for the initiation of cell growth. One of the media used during continuous experiments consisted of a salt mixture alone and the other a nutrient medium containing a salt mixture with yeast extract and peptone. Effluent pH was controlled by supplying various fractions of the two different types of media. A nutrient medium fraction above 0.6 was crucial for successful fermentation in a trickle bed reactor. The nutrient medium fraction is the ratio of the volume of the nutrient medium to the total volume of nutrient plus salt medium. Supplying nutrient medium to both columns continuously was an effective way to meet both pH and nutrient requirement. A 257-mL reactor could ferment 45 g/L glucose from an initial concentration of 60 g/L glucose at a rate of 70 mL/h. Butanol, acetone, and ethanol concentrations were 8.82, 5.22, and 1.45 g/L, respectively, with a butanol and total solvent yield of 19.4 and 34.1 wt %. Solvent productivity in an immobilized cell trickle bed reactor was 4.2 g/L h, which was 10 times higher than that obtained in a batch fermentation using free cells and 2.76 times higher than that of an immobilized CSTR. If the nutrient medium fraction was below 0.6 and the pH was below 4.2, the system degenerated. Oxygen also contributed to the system degeneration. Upon degeneration, glucose consumption and solvent yield decreased to 30.9 g/L and 23.0 wt %, respectively. The yield of total liquid product (40.0 wt %) and butanol selectivity (60.0 wt %) remained almost constant. Once the cells were degenerated

  15. Vision of irrigation

    Directory of Open Access Journals (Sweden)

    Fernando Braz-Tangerino

    2014-08-01

    Full Text Available Irrigation not only has been a key factor for the development and maintenance of human societies but it still plays this role now and it is foreseen that in the future as well. Its evolution has been constrained to the advance in knowledge on matters regarding Agronomy and Water Engineering and in technology however, many challenges deserve further research. It is worth to note that Brazil has strongly promoted irrigation in the last decade. Within the limited extension of this article, some current topics in irrigation, some of them are innovative such us the research line studying water flow in soil-plant in Mediterranean plants and its consequences on water use,. and future challenges are presented with the purpose of stimulate publication of Irrigation papers in the journal “Ingeniería del Agua” among Portuguese and Spanish language communities.

  16. Advances in Irrigation

    Science.gov (United States)

    Gardner, W. R.

    This is the first volume of Advances in Irrigation, a new serial publication by the publishers of Advances in Agronomy and Advances in Hydroscience and designed to follow the same format. The editor is a well-known researcher and writer on irrigation and related subjects and has assembled a collection of highly regarded and respected authors for the initial volume. The readership for this volume will probably be mainly specialists and students interested in irrigation and an occasional design engineer.The seven contributions in this volume fall roughly into two classes: research and practice. Three papers (“Conjunctive Use of Rainfall and Irrigation in Semi-arid Regions,” by Stewart and Musik, “Irrigation Scheduling Using Soil Moisture Measurements: Theory and Practice,” by G. S. and M. D. Campbell, and “Use of Solute Transport Models to Estimate Salt Balance Below Irrigated Cropland,” by Jury) cover topics that have been the subject of a number of reviews. The contributions here provide brief, well-written, and authoritative summaries of the chosen topics and serve as good introductions or reviews. They should lend themselves well to classroom use in various ways. They also should be helpful to the nonspecialist interested in getting a sense of the subject without going into great detail.

  17. 滴流床反应器中液体扩散的分形表征%FRACTAL CHARACTERIZATION OF LIQUID DISPERSION IN TRICKLE BED REACTOR

    Institute of Scientific and Technical Information of China (English)

    朱慧铭; 刘秀凤; 李冬; 张宝泉

    2004-01-01

    @@ INTRODUCTION Dispersion is very important to the design of trickle bed reactor for both chemical and biochemical processes. The degree of dispersion often influences reactor performance and scale-up.

  18. The Checkpoint Immunotherapy Revolution: What Started as a Trickle Has Become a Flood, Despite Some Daunting Adverse Effects; New Drugs, Indications, and Combinations Continue to Emerge.

    Science.gov (United States)

    Alexander, Walter

    2016-03-01

    What started as a trickle of new agents that help the body's immune system fight cancer has now become a flood, despite some daunting adverse effects. This report discusses the new drugs, indications, and combinations that continue to emerge.

  19. The function of a toluene-degrading bacterial community in a waste gas trickling filter

    DEFF Research Database (Denmark)

    Pedersen, A.R.; Arvin, E.

    1999-01-01

    oligonucleotide 16S ribosomal RNA probe targeting the toluene-degrading species Pseudomonas putida, and by computer simulations (AQUASIM) of the biofilm growth based on a food web model. Biofilms were taken from a lab-scale trickling filter for treatment of toluene-polluted air. The biofilm growth......The function of a community of toluene-degrading bacteria in a biofilm system was investigated with regard to growth and toluene degradation in order to investigate substrate interactions in the community. This was done by the combination of experimental observations using a specific...... and the activity of P. putida, a representative of the toluene-degrading species in the biofilm which have been described previously (Pedersen et al., 1997) were simulated. The simulation indicated that the volume fraction of the toluene degraders in the biofilm decreased from 12% to only 2% (11% of dry weight...

  20. Trickle-Down Preferences: Preferential Conformity to High Status Peers in Fashion Choices.

    Science.gov (United States)

    Galak, Jeff; Gray, Kurt; Elbert, Igor; Strohminger, Nina

    2016-01-01

    How much do our choices represent stable inner preferences versus social conformity? We examine conformity and consistency in sartorial choices surrounding a common life event of new norm exposure: relocation. A large-scale dataset of individual purchases of women's shoes (16,236 transactions) across five years and 2,007 women reveals a balance of conformity and consistency, moderated by changes in location socioeconomic status. Women conform to new local norms (i.e., average heel size) when moving to relatively higher status locations, but mostly ignore new local norms when moving to relatively lower status locations. In short, at periods of transition, it is the fashion norms of the rich that trickle down to consumers. These analyses provide the first naturalistic large-scale demonstration of the tension between psychological conformity and consistency, with real decisions in a highly visible context.

  1. Trickle-Down Preferences: Preferential Conformity to High Status Peers in Fashion Choices.

    Directory of Open Access Journals (Sweden)

    Jeff Galak

    Full Text Available How much do our choices represent stable inner preferences versus social conformity? We examine conformity and consistency in sartorial choices surrounding a common life event of new norm exposure: relocation. A large-scale dataset of individual purchases of women's shoes (16,236 transactions across five years and 2,007 women reveals a balance of conformity and consistency, moderated by changes in location socioeconomic status. Women conform to new local norms (i.e., average heel size when moving to relatively higher status locations, but mostly ignore new local norms when moving to relatively lower status locations. In short, at periods of transition, it is the fashion norms of the rich that trickle down to consumers. These analyses provide the first naturalistic large-scale demonstration of the tension between psychological conformity and consistency, with real decisions in a highly visible context.

  2. Yield optimization in a cycled trickle-bed reactor: ethanol catalytic oxidation as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Ayude, A.; Haure, P. [INTEMA, CONICET, Mar del Plata (Argentina); Cassanello, M. [Universidad de Buenos Aires, PINMATE, Departamento de Industrias, FCEyN, Buenos Aires (Argentina); Martinez, O. [Departamento de Ingenieria Quimica, FI-UNLP-CINDECA, La Plata (Argentina)

    2012-05-15

    The effect of slow ON-OFF liquid flow modulation on the yield of consecutive reactions is investigated for oxidation of aqueous ethanol solutions using a 0.5 % Pd/Al{sub 2}O{sub 3} commercial catalyst in a laboratory trickle-bed reactor. Experiments with modulated liquid flow rate (MLFR) were performed under the same hydrodynamic conditions (degree of wetting, liquid holdup) as experiments with constant liquid flow rate (CLFR). Thus, the impact of the duration of wet and dry cycles as well as the period can be independently investigated. Depending on cycling conditions, acetaldehyde or acetic acid production is favored with MLFR compared to CLFR. Results suggest both the opportunity and challenge of finding a way to tune the cycling parameters for producing the most appropriate product. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Hydrotreating of used oil; Prediction of industrial trickle-bed operation from pilot-plant data

    Energy Technology Data Exchange (ETDEWEB)

    Skala, D.U.; Saban, M.D.; Orlovie, M. (Belgrade Univ. (Yugoslavia). Tehnolosko-Metalurski Fakultet); Meyn, V.W.; Severin, D.K.; Rahimian, I.G.H. (German Inst. for Petroleum Research, 3392 Clausthal-Zellerfeld (DE)); Marjanovic, M.V. (Refinery Beograd, Pancevacki put 83, 11001 Beograd (YU))

    1991-09-01

    This paper reports on oil hydrotreating that was investigated in a pilot trickle-bed reactor (TBR) at 270-350{degrees} C, 5-7 MPa, and 1.1-4.6 liquid hourly space velocity (LHSV) and with different hydrogen/oil ratios using a commercial Co-Mo/Al{sub 2}O{sub 3} catalyst. Hydrodesulfurization (HDS), hydrodeoxygenation (HDO), and metals removal were investigated by using a modified power- law kinetic model with a power term for LHSV. It was found that the HDS and HDO reactions can be described by pseudo- first-order kinetics. The removal of metals was found to be primarily due to the physical process of deposition on the catalyst bed. With the use of the kinetic data from a pilot plant, the simulation of an industrial TBR was performed. Simulated HDS and HDO, removal of metals, and prediction of catalyst deactivation agreed well with the industrial data for three charges of catalyst.

  4. Microbial biofilm community in a thermophilic trickling bio filter used for continuous biohydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Y.; Park, E.-J. [Korea Advanced Inst. of Science and Technology, Daejeon (Korea, Republic of). Dept. of Chemical and Biomolecular Engineering; Oh, Y.-K. [Pusan National Univ., Pusan (Korea, Republic of). Dept. of Chemical Engineering; Park, S. [Pusan National Univ., Pusan (Korea, Republic of). Dept. of Chemical Engineering]|[Pusan National Univ., Pusan (Korea, Republic of). Inst. for Environmental Technology and Industry

    2004-07-01

    The microbial community in a thermophilic trickling biofilter reactor (TBR) that produces biohydrogen was examined. In particular, nonculture-based molecular methods were used to characterize the microbial community in the biofilm formed on the matrixes that were packed in the reactor. The operation of the bioreactor was described. TBR demonstrated long term stability to produce hydrogen. Biomass volatile suspended solids (VSS) in the TBR decreased gradually as bed height increased from the bottom of the bed. Epifluorescence microscopy of 6-diamidino-2-phenylindole (DAPI)-stained cells and denaturing gradient gel electrophoresis (DGGE) analysis both indicate that microbial composition changes in the TBR according to bed height. The dominant phylogenetic groups in the system were identified along with the comparative analysis of morphology of microbial community and the DGGE profiles of the microbial community in terms of total genomic DNA extracted from biofilm cells. 10 refs., 1 tab., 5 figs.

  5. Hydrogen sulfide removal from air by Acidithiobacillus thiooxidans in a trickle bed reactor.

    Science.gov (United States)

    Ramirez, M; Gómez, J M; Cantero, D; Páca, J; Halecký, M; Kozliak, E I; Sobotka, M

    2009-09-01

    A strain of Acidithiobacillus thiooxidans immobilized in polyurethane foam was utilized for H(2)S removal in a bench-scale trickle-bed reactor, testing the limits of acidity and SO(4) (2-) accumulation. The use of this acidophilic strain resulted in remarkable stability in the performance of the system. The reactor maintained a >98-99 % H(2)S removal efficiency for c of up to 66 ppmv and empty bed residence time 98 % H(2)S was achieved under steady-state conditions, over the pH range of 0.44-7.30. Despite the accumulation of acidity and SO(4) (2-) (up to 97 g/L), the system operated without inhibition.

  6. Experimental analysis and evaluation of the mass transfer process in a trickle-bed reactor

    Directory of Open Access Journals (Sweden)

    Silva J.D.

    2003-01-01

    Full Text Available A transient experimental analysis of a three-phase descendent-cocurrent trickle-bed H2O/CH4-Ar/g -Al2O3 system was made using the stimulus-response technique, with the gas phase as a reference. Methane was used as a tracer and injected into the argon feed and the concentration vs time profiles were obtained at the entrance and exit of the bed, which were maintained at 298K and 1.013 10(5 Pa. A mathematical model for the tracer was developed to estimate the axial dispersion overall gas-liquid mass transfer and liquid-solid mass transfer coefficients. Experimental and theoretical results were compared and shown to be in good agreement. The model was validated by two additional experiments, and the values of the coefficients obtained above were confirmed.

  7. Experimental single and trickle infections of cattle with Taenia saginata: Studies of immunodiagnosis

    DEFF Research Database (Denmark)

    Bøgh, H.O.; Grønvold, J.; Maeda, G.E.

    1996-01-01

    Two groups of 12 calves were given either a single infection dose of 30,000 Taenia saginata eggs (group A) or trickle infected with 12 x 2500 T saginata eggs (group B). The calves were killed 16, 22 or 54 weeks after infection and the numbers of viable and dead parasites were counted by slicing...... by using an ELISA and a dot blot procedure for the detection of antibody in the serum of the infected calves; an initial increase in response during the first 10 weeks after infection was generally followed by a gradual decline. When using a monoclonal antibody-based ELISA for the detection of circulating......-detecting ELISA. However, several other animals which harboured between two and 41 viable cysts at slaughter did not react....

  8. Liquid spreading in trickle-bed reactors: Experiments and numerical simulations using Eulerian--Eulerian two-fluid approach

    CERN Document Server

    Solomenko, Z; Fourati, Manel; Larachi, Faical; Boyer, Christophe; Augier, Frédéric

    2015-01-01

    Liquid spreading in gas-liquid concurrent trickle-bed reactors is simulated using an Eulerian twofluid CFD approach. In order to propose a model that describes exhaustively all interaction forces acting on each fluid phase with an emphasis on dispersion mechanisms, a discussion of closure laws available in the literature is proposed. Liquid dispersion is recognized to result from two main mechanisms: capillary and mechanical (Attou and Ferschneider, 2000; Lappalainen et al., 2009- The proposed model is then implemented in two trickle-bed configurations matching with two experimental set ups: In the first configuration, simulations on a 2D axisymmetric geometry are considered and the model is validated upon a new set of experimental data. Overall pressure drop and liquid distribution obtained from $\\gamma$-ray tomography are provided for different geometrical and operating conditions. In the second configuration, a 3D simulation is considered and the model is compared to experimental liquid flux patterns at th...

  9. SEDIMENT CONTROL FOR IRRIGATION INTAKES

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The analysis of the sediment problems in irrigation engineeringwas carried out, and the layout, the method as well as the effect of sediment control for irrigation intake structures in China were briefly introduced.

  10. Use of shredded tire chips and tire crumbs as packing media in trickling filter systems for landfill leachate treatment.

    Science.gov (United States)

    Mondal, B; Warith, M A

    2008-08-01

    Scrap tire stockpiles are breeding grounds for pests, mosquitoes and west Nile viruses and, thereby, become a potential health risk. This experimental study was carried out in six stages to determine the suitability of shredded tire materials in a trickling filter system to treat landfill leachate. Biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and NH3-N removals were obtained in the range of 81 to 96%, 76 to 90% and 15 to 68%, respectively. The removal of organics appears to be largely related to total dissolved solids reduction in leachate. A sudden increase, from time to time, in organic content of effluent could be attributed to biomass sloughing and clogging in the trickling filters. However, tire crumbs exhibited more consistent organics removal throughout the experimental program. Due to the high surface area of shredded tire chips and crumbs, a layer of biomass, 1-2 mm thick, was attached to them and was sloughed off at an interval of 21 days. Apart from that, as shredded tires are comparatively cheaper than any other usable packing material, tire chips and tire crumbs appeared to be quite promising as packing media in trickling filters for landfill leachate treatment.

  11. Characterization and removal of specific organic constituents in an UASB-trickling-filter system treating domestic wastewater.

    Science.gov (United States)

    Pontes, Patrícia Procópio; Chernicharo, Carlos Augusto de Lemos

    2011-01-01

    This paper presents the characterization of specific organic constituents (carbohydrates, proteins and lipids) in raw sewage and in the anaerobic and aerobic effluents of a demo-scale (500 inhabitants) UASB- trickling-filter system. The evaluation of such parameters was carried out for two operating conditions, either without sludge recirculation (experiment I) from the trickling filter to the UASB reactor or with sludge recirculation (experiment II), for sludge thickening and stabilization, in the anaerobic reactor. The results showed that the contribution of acetic acid, carbohydrates, proteins and lipids amounted for approximately 70% of the total COD fed to the UASB during experiment I, whereas during experiment II these constituents amounted for only around 40% of the total COD. Although very high BOD and COD overall removal efficiencies were observed for the treatment system (around 90% and 80%, respectively), it was possible to infer that these efficiencies were mainly related to the removal of carbohydrates and lipids (around 80% removal), and of other non-identified constituents. The removal of proteins was much lower (around 50% removal), and the relative contribution of proteins to the total COD increased along the treatment course, being responsible for most of the residual COD of the treatment units. In the present system configuration, the UASB reactor played a major role in the removal of carbohydrates, whereas the trickling filter was very effective in the removal of lipids. The return of aerobic sludge for thickening and stabilization in the UASB reactor did not affect its performance.

  12. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  13. Planning for an Irrigation System.

    Science.gov (United States)

    Turner, J. Howard; Anderson, Carl L.

    The publication, with the aid of tables and colored illustrations and diagrams, presents information to help the farmer who is considering the installation of an irrigation system determine whether or not to irrigate, the type of system to use, and the irrigation cost and return on investment. Information is presented on the increase in yield to…

  14. Evaluating two irrigation controllers under subsurface drip irrigated tomato crop

    Directory of Open Access Journals (Sweden)

    Hussein M. Al-Ghobari

    2016-12-01

    Full Text Available Smart systems could be used to improve irrigation scheduling and save water under Saudi Arabia’s present water crisis scenario. This study investigated two types of evapotranspiration-based smart irrigation controllers, SmartLine and Hunter Pro-C2, as promising tools for scheduling irrigation and quantifying plants’ water requirements to achieve water savings. The effectiveness of these technologies in reducing the amount of irrigation water was compared with the conventional irrigation scheduling method as a control treatment. The two smart irrigation sensors were used for subsurface irrigation of a tomato crop (cv. Nema in an arid region. The results showed that the smart controllers significantly reduced the amount of applied water and increased the crop yield. In general, the Hunter Pro-C2 system saved the highest amount of water and produced the highest crop yield, resulting in the highest water irrigation efficiency compared with the SmartLine controller and the traditional irrigation schedule. It can be concluded that the application of advanced scheduling irrigation techniques such as the Hunter controller under arid conditions can realise economic benefits by saving large amounts of irrigation water.

  15. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  16. Selective adhesion of wastewater bacteria to Pleurotus ostreatus mycelium in a trickle-bed bioreactor

    Directory of Open Access Journals (Sweden)

    Čeněk Novotný

    2016-07-01

    Full Text Available The work is focused on spontaneous colonization of fungal mycelium by invading microorganisms in a trickle-bed fungal bioreactor operating under semi-sterile conditions. Pleurotus ostreatus was grown under the flow of synthetic wastewater containing activated sludge bacteria and the microbial consortium developed in the reactor was characterized. Genotype and phenotype profile of the reactor-invading, bacterial consortium was clearly distinctive from that of the original activated sludge. The bacterial consortium from the reactor contained a higher portion of bacteria capable of cellobiose utilization and a small amount of bacteria with the ability to utilize benzoic acids. The invading bacteria had no effect on the dye decolorization performance of the fungal reactor. Five bacterial strains colonizing P. ostreatus reactor cultures were isolated and identified as species of the genera Pseudomonas and Bacillus. Except for Bacillus cereus all strains displayed a potential to inhibit fungal growth on solid media (14 to 51 % inhibition which was comparable or higher than that of the reference bacterial strains. The pH- and media composition-dependence of the growth inhibition was demonstrated.

  17. Pathology and clinicopathology of buffalo against trickle infection with Fasciola gigantica

    Directory of Open Access Journals (Sweden)

    Ening Wiedosari

    1998-06-01

    Full Text Available Eleven male buffalo calves were divided into infected group of 7 animals and non-infected control group of 4 animals. The infected group was then inoculated with trickle doses of 15 Inetacercariae of Fasciola gigantica twice weekly for 32 weeks and killed 36 weeks after first infection. There were no clinical symptoms observed . Infected and non-infected buffaloes, had similar values of packed cell volume, haemoglobin and red blood cell counts . In infected buffaloes, plasma glutamate dehydrogenase enzyme activity increased in proportion to the dregree of hepatocyte destruction level and evidence of necrosis caused by the migrating of immature flukes through the parenchyma prior to their entry into the bile ducts. While the values of plasma glutamyl transpeptidase showed only a minimal rise with a small peak in week 20 as evidenced by histological observation that infected caused limited damage to epithelial surface of the bile duct . These results indicates that, the resistance mechaninisms of buffalo against fasciolosis infection occurred in the liver or before flukes entering into the bile ducts. These results seem to indicate that, in buffalo, resistance mechanisms to fasciolosis infection occured in the liver or before flukes entry into the bile ducts.

  18. The application of moving bed biofilm reactor to denitrification process after trickling filters.

    Science.gov (United States)

    Kopec, Lukasz; Drewnowski, Jakub; Kopec, Adam

    2016-12-01

    The paper presents research of a prototype moving bed biofilm reactor (MBBR). The device was used for the post-denitrification process and was installed at the end of a technological system consisting of a septic tank and two trickling filters. The concentrations of suspended biomass and biomass attached on the EvU Perl moving bed surface were determined. The impact of the external organic carbon concentration on the denitrification rate and efficiency of total nitrogen removal was also examined. The study showed that the greater part of the biomass was in the suspended form and only 6% of the total biomass was attached to the surface of the moving bed. Abrasion forces between carriers of the moving bed caused the fast stripping of attached microorganisms and formation of flocs. Thanks to immobilization of a small amount of biomass, the MBBR was less prone to leaching of the biomass and the occurrence of scum and swelling sludge. It was revealed that the maximum rate of denitrification was an average of 0.73 gN-NO(3)/gDM·d (DM: dry matter), and was achieved when the reactor was maintained in external organic carbon concentration exceeding 300 mgO2/dm(3) chemical oxygen demand. The reactor proved to be an effective device enabling the increase of total nitrogen removal from 53.5% to 86.0%.

  19. Continuous xylanase production with Aspergillus nidulans under pyridoxine limitation using a trickle bed reactor.

    Science.gov (United States)

    Müller, Michael; Prade, Rolf A; Segato, Fernando; Atiyeh, Hasan K; Wilkins, Mark R

    2015-01-01

    A trickle bed reactor (TBR) with recycle was designed and tested using Aspergillus nidulans with a pyridoxine marker and over-expressing/secreting recombinant client xylanase B (XynB). The pyridoxine marker prevented the fungus from synthesizing its own pyridoxine and fungus was unable to grow when no pyridoxine was present in the medium; however, enzyme production was unaffected. Uncontrolled mycelia growth that led to clogging of the TBR was observed when fungus without a pyridoxine marker was used for XynB production. Using the fungus with pyridoxine marker, the TBR was operated continuously for 18 days and achieved a XynB output of 41 U/ml with an influent and effluent flow rate of 0.5 ml/min and a recycle flow rate of 56 ml/min. Production yields in the TBR were 1.4 times greater than a static tray culture and between 1.1 and 67 times greater than yields for SSF enzyme production stated in the literature.

  20. An analysis of a trickle-bed bioreactor: Carbon disulfide removal

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, R.; Revah, S.; Viveros-Garcia, T. [Univ. Autonoma Metropolitana-Iztapalapa (Mexico). Dept. de Ingenieria de Procesos e Hidraulica

    1999-04-05

    An analysis of the local processes occurring in a trickle-bed bioreactor (TBB) with a first-order bioreaction shows that the identification of the TBB operating regime requires knowledge of the substrate concentration in the liquid phase. If the substrate liquid concentration is close to 0, the rate-controlling step is mass transfer at the gas-liquid interface; when it is close to the value in equilibrium with the gas phase, the controlling step is the phenomena occurring in the biofilm, CS{sub 2} removal rate data obtained in a TBB with a Thiobacilii consortia biofilm are analyzed to obtain the mass transfer and kinetic parameters, and to show that the bioreactor operates in a regime mainly controlled by mass transfer. A TBB model with two experimentally determined parameters is developed and used to show how the bioreactor size depends on the rate-limiting step, the absorption factor, the substrate fractional conversion, and on the gas and liquid contact pattern. Under certain conditions, the TBB size is independent of the flowing phases` contact pattern. The model effectively describes substrate gas and liquid concentration data for mass transfer and biodegradation rate controlled processes.

  1. Hydrodenitrogenation of Aleksinac shale oil distillates in a pilot trickle-bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Saban, M.D.; Skala, D.U.; Jovanovic, J.A.; Mayn, V.W.; Rahimian, I.G.-H. (University of Belgrade, Belgrade (Yugoslavia). Faculty of Technology and Metallurgy)

    1992-02-01

    Hydrodenitrogenation (HDN) of the Aleksinac shale oil distillates was studied in a pilot trickle-bed reactor at 340-435{degree}C, 8.0 MPa, 1-4.57 h{sup -1} liquid hourly space velocity (LHSV) and 500 cm{sup 3} (STP) of H{sub 2}/cm{sup 3} oil. The commercial Co-Mo/Al{sub 2}O{sub 3} and Ni-Mo/Al{sub 2}O{sub 3} presulfided catalysts were evaluated for the HDN of three different shale oil distillates. The initial HDN catalyst deactivation was followed using a linear catalyst deactivation model. The Ni-Mo/Al{sub 2}O{sub 3} catalyst showed somewhat higher initial HDN activity and lower initial deactivation rate than the Co-Mo/Al{sub 2}O{sub 3} catalyst for the first 30-45 h on shale oil feedstock. Nitriles in shale oil first undergo HDN reaction at mild operating conditions, much faster than five-and six-membered nitrogen heterocyclic compounds. The overall HDN kinetics of refractive nitrogen in shale oil was analyzed using a modified pseudo-first order behaviour. The on-line measured hydrogen consumption was in the range 200-300 cm{sup 3}(STP)/cm{sup 3} for HDN{gt}80% regardless of the catalyst type and feedstock. 31 refs., 7 figs., 7 tabs.

  2. Determination of the hydraulic residence time of trickling filters using radiotracer experiments

    Energy Technology Data Exchange (ETDEWEB)

    Debien, Bruno R.; Ferreira, Ladislau M.; Barreto, Alberto A.; Pinto, Amenonia M.F., E-mail: brunordebien@gmail.com [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Geografia. Lab. de Geomorfologia; Moreira, Rubens M., E-mail: aab@cdtn.br, E-mail: amfp@cdtn.br, E-mail: rubens@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Trickling filters (TF) are bioreactors fulfilled with inert materials working as support for biofilm development, and have been used in a large scale in wastewater treatment for organic matter, ammonia nitrogen and nitrate removal. TF's can be widely used in Brazil, especially because of its simplicity and operational low cost. The efficiency of pollutants removal processes depends on the water flow dynamics inside the reactor. For this reason, in the present work the mean residence time of two TF's containing different support materials were determined by means of tracer testes. The radioisotope 82Br - a gamma radiation emitter, produced from soluble potassium bromide irradiated in the TRIGA reactor at the Centre for the Development of Nuclear Energy (CDTN) - was used as a pseudo-conservative tracer for the comparative study of aqueous phase flow dynamics in both TF's. Mean residence time for the first TF (containing a single support material) was 0,3 hours, much smaller than the value obtained for the second TF (containing two alternated support materials), around 2 hours. These results were already expected, once the alternated material is denser than the single one, and are very important for numerical modeling studies aiming to determine the kinetic constant for removal of the pollutants cited above. (author)

  3. A comparative study in treating two VOC mixtures in trickle bed air biofilters.

    Science.gov (United States)

    Cai, Zhangli; Kim, Daekeun; Sorial, George A

    2007-06-01

    Two independent parallel trickling bed air biofilters (TBABs) ("A" and "B") with two different typical VOC mixtures were investigated. Toluene, styrene, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK) were the target VOCs in the mixtures. Biofilter "A" was fed equal molar ratio of the VOCs and biofilter "B" was fed a mixture based on EPA 2003 emission report. Backwashing and substrate starvation operation were conducted as biomass control. Biofilter "A" and "B" maintained 99% overall removal efficiency for influent concentration up to 500 and 300 ppmv under backwashing operating condition, respectively. The starvation study indicated that it can be an effective biomass control for influent concentrations up to 250 ppmv for biofilter "A" and 300 ppmv for "B". Re-acclimation of biofilter performance was delayed with increase of influent concentration for both biofilters. Starvation operation helped the biofilter to recover at low concentrations and delayed re-acclimation at high concentrations. Furthermore, re-acclamation for biofilter "B" was delayed due to its high toluene content as compared to biofilter "A". The pseudo first-order removal rate constant decreased with increase of volumetric loading rate for both biofilters. MEK and MIBK were completely removed in the upper 3/8 media depth. While biofilter depth utilization for the removal of styrene and toluene increased with increase of influent concentrations for both biofilters. However, toluene removal utilized more biofilter depth for biofilter "B" as compared to biofilter "A".

  4. Decolorization of the AO24 azo dye and reduction of toxicity and genotoxicity in trickling biofilters.

    Science.gov (United States)

    Garzóón-Zúñga, Marco A; Sandoval-Villasana, Ana M; Moeller-Chávez, Gabriela E

    2011-02-01

    Acid Orange 24 (AO24) dye was degraded in a trickling biofilter packed with peat and wood chips and inoculated with biomass from a petrochemical industry wastewater system. Different operating strategies were tested; in the first stage, two biofilters were operated independently--one non-aerated biofilter (passive) and the other with aeration-subsequently, the systems were operated serially, and effluent from the non-aerated biofilter was fed to the biofilter with aeration. This treatment train was used to test three different filtration velocities--0.141, 0.282, and 0.423 m/d. The results show that, when operating the systems with a dye charge of 0.035 kg AO24 m2/d and treating the effluent in a single step, good removal efficiencies of AO24 (95 and 89%), COD (63 and 53%), and acute toxicity (63 and 78%) were obtained in both biofilters (with and without air), although mutagenic and potentially carcinogenic intermediary compounds were not removed, because genotoxicity exhibits values higher than 2.0 units for the mutation rate. When using the non-aerated biofilter/aerated biofilter treatment train, it is possible to treat a dye charge 3 times greater (0.106 kg AO24 m2/d) and efficiently remove 98% AO24, 76% COD, 100% acute toxicity, and 100% genotoxicity, which indicates that, with this biological system, an advanced degree of biotransformation and mineralization of the azo dye AO24 is achieved.

  5. Treatment of table olive washing water using trickling filters, constructed wetlands and electrooxidation.

    Science.gov (United States)

    Tatoulis, Triantafyllos; Stefanakis, Alexandros; Frontistis, Zacharias; Akratos, Christos S; Tekerlekopoulou, Athanasia G; Mantzavinos, Dionissios; Vayenas, Dimitrios V

    2017-01-01

    The production of table olives is a significant economic activity in Mediterranean countries. Table olive processing generates large volumes of rinsing water that are characterized by high organic matter and phenol contents. Due to these characteristics, a combination of more than one technology is imperative to ensure efficient treatment with low operational cost. Previously, biological filters were combined with electrooxidation to treat table olive washing water. Although this combination was successful in reducing pollutant loads, its cost could be further reduced. Constructed wetlands could be an eligible treatment method for integrated table olive washing water treatment as they have proved tolerant to high organic matter and phenol loads. Two pilot-scale horizontal subsurface constructed wetlands, one planted and one unplanted, were combined with a biological filter and electrooxidation over a boron-doped diamond anode to treat table olive washing water. In the biological filter inlet, chemical oxygen demand (COD) concentrations ranged from 5500 to 15,000 mg/L, while mean COD influent concentration in the constructed wetlands was 2800 mg/L. The wetlands proved to be an efficient intermediate treatment stage, since COD removal levels for the planted unit reached 99 % (mean 70 %), while the unplanted unit presented removal rates of around 65 %. Moreover, the concentration of phenols in the effluent was typically below 100 mg/L. The integrated trickling filter-constructed wetland-electrooxidation treatment system examined here could mineralize and decolorize table olive washing water and fully remove its phenolic content.

  6. A combined upflow anaerobic sludge bed and trickling biofilter process for the treatment of swine wastewater.

    Science.gov (United States)

    Zhao, Bowei; Li, Jiangzheng; Buelna, Gerardo; Dubé, Rino; Le Bihan, Yann

    2016-01-01

    A combined upflow anaerobic sludge blanket (UASB)-trickling biofilter (TBF) process was constructed to treat swine wastewater, a typical high-strength organic wastewater with low carbon/nitrogen ratio and ammonia toxicity. The results showed that the UASB-TBF system can remarkably enhance the removal of pollutants in the swine wastewater. At an organic loading rate of 2.29 kg/m(3) d and hydraulic retention time of 48 h in the UASB, the chemical oxygen demand (COD), Suspended Solids and Total Kjeldahl Nitrogen removals of the combined process reached 83.6%, 84.1% and 41.2%, respectively. In the combined system the UASB served as a pretreatment process for COD removal while nitrification and denitrification occurred only in the TBF process. The TBF performed reasonably well at a surface hydraulic load as high as 0.12 m(3)/m(2) d. Since the ratio of influent COD to total mineral nitrogen was less than 3.23, it is reasonable to suggest that the wood chips in TBF can serve as a new carbon source for denitrification.

  7. Converting Surface Irrigation to Pressurized Irrigation Systems and its Effecton Yield of OrangeTrees (Case Study:North of Khouzestan

    Directory of Open Access Journals (Sweden)

    M. Khorramian

    2017-01-01

    Full Text Available Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation efficiency with low-volume pressurized irrigation systems, citrus trees have adapted with these new irrigation systems. However limited information exists on the performance of mature orchards converted from border surface irrigation to pressurized irrigation systems. Therefore, the current research was conducted to evaluate the feasibility of converting surface irrigation to pressurized irrigation systems on mature citrus trees in climate conditions of North Khouzestan. Materials and Methods: This study was conducted during three years at Safiabad Agricultural Research Center to evaluate the yield of citrus trees and the quality of fruits for two Marss and Valencia varieties which grow 7 years previously with surface irrigation and converted to pressurized irrigation systems. The treatments consisted of six irrigation methods including Overhead sprinkle irrigation (OHSI, Under tree sprinkle irrigation(UTSI, Trickle irrigation(TI(six 8 L/h Netafim emitters, Microjet irrigation (MI(two 180 microjet were located under canopy near of the trunk at opposite sides of trunk,Bubbler irrigation(BI(a single located under the canopy of each treeandSurface irrigation(SI method.Soil texture was clay loam well drained without salinity(ECe=0.69ds m-1, with 1.25 percent organic carbon. The experimental design was completely randomized design. The trees were irrigated during spring and summer seasons. For calculating irrigation water depth in TI, MI and BI systems, daily evaporation from a class A evaporation pan of the Safiabad weather station (nearby the experimental field was collected, and evapotranspiration of the citrus trees was calculated applying a

  8. Spectrophotometric determination of irrigant extrusion using passive ultrasonic irrigation, EndoActivator, or syringe irrigation.

    Science.gov (United States)

    Rodríguez-Figueroa, Carolina; McClanahan, Scott B; Bowles, Walter R

    2014-10-01

    Sodium hypochlorite (NaOCl) irrigation is critical to endodontic success, and several new methods have been developed to improve irrigation efficacy (eg, passive ultrasonic irrigation [PUI] and EndoActivator [EA]). Using a novel spectrophotometric method, this study evaluated NaOCl irrigant extrusion during canal irrigation. One hundred fourteen single-rooted extracted teeth were decoronated to leave 15 mm of the root length for each tooth. Cleaning and shaping of the teeth were completed using standardized hand and rotary instrumentation to an apical file size #40/0.04 taper. Roots were sealed (not apex), and 54 straight roots (n = 18/group) and 60 curved roots (>20° curvature, n = 20/group) were included. Teeth were irrigated with 5.25% NaOCl by 1 of 3 methods: passive irrigation with needle, PUI, or EA irrigation. Extrusion of NaOCl was evaluated using a pH indicator and a spectrophotometer. Standard curves were prepared with known amounts of irrigant to quantify amounts in unknown samples. Irrigant extrusion was minimal with all methods, with most teeth showing no NaOCl extrusion in straight or curved roots. Minor NaOCl extrusion (1-3 μL) in straight roots or curved roots occurred in 10%-11% of teeth in all 3 irrigant methods. Two teeth in both the syringe irrigation and the EA group extruded 3-10 μL of NaOCl. The spectrophotometric method used in this study proved to be very sensitive while providing quantification of the irrigant levels extruded. Using the PUI or EA tip to within 1 mm of the working length appears to be fairly safe, but apical anatomy can vary in teeth to allow extrusion of irrigant. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Irrigation mitigates against heat extremes

    Science.gov (United States)

    Thiery, Wim; Fischer, Erich; Visser, Auke; Hirsch, Annette L.; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2017-04-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use gridded observations and ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on hot extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Finally we find that present-day irrigation is partly masking GHG-induced warming of extreme temperatures, with particularly strong effects in South Asia. Our results overall underline that irrigation substantially reduces our exposure to hot temperature extremes and highlight the need to account for irrigation in future climate projections.

  10. Asian irrigation, African rain: Remote impacts of irrigation

    Science.gov (United States)

    Vrese, Philipp; Hagemann, Stefan; Claussen, Martin

    2016-04-01

    Irrigation is not only vital for global food security but also constitutes an anthropogenic land use change, known to have strong effects on local hydrological and energy cycles. Using the Max Planck Institute for Meteorology's Earth System Model, we show that related impacts are not confined regionally but that possibly as much as 40% of the present-day precipitation in some of the arid regions in Eastern Africa are related to irrigation-based agriculture in Asia. Irrigation in South Asia also substantially influences the climate throughout Southeast Asia and China via the advection of water vapor and by altering the Asian monsoon. The simulated impact of irrigation on remote regions is sensitive to the magnitude of the irrigation-induced moisture flux. Therefore, it is likely that a future extension or decline of irrigated areas due to increasing food demand or declining fresh water resources will also affect precipitation and temperatures in remote regions.

  11. 陶瓷球填料生物滴滤塔降解甲苯废气%PURIFYING WASTE GAS CONTAINING LOW CONCENTRATION TOLUENE IN TRICKLING BIOFILTER WITH CERAMIC SPHERES

    Institute of Scientific and Technical Information of China (English)

    廖强; 田鑫; 朱恂; 王永忠; 陈蓉; 廖浩

    2003-01-01

    The Purification experiments of waste gas containing low concentration toluene were made in trickling biofilter with ceramic spheres. The effects of liquid flow rate,gas flow rate,pH of circulation liquid, and toluene concentration in inlet gas on the purification efficiency of trickling biofilter were investigated. The pressure drop of the trickling biofilter was also measured during experiments.Increasing liquid flow rate and gas flow rate resulted in the decrease of purification efficiency of trickling biofilter. The highest purification efficiency of trickling biofilter was found at the circulation liquid pH of 7. The porosity of the packing material at the inlet of gas was higher than that at the outlet of gas in biofilter after continuous operation in 50 days. The decrease in the porosity of packing material caused a great increase in the pressure drop of the biofilter.

  12. Effect of low‐cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    National Research Council Canada - National Science Library

    Keraita, Bernard; Konradsen, Flemming; Drechsel, Pay; Abaidoo, Robert C

    2007-01-01

    Objective  To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water...

  13. Making the user visible: analysing irrigation practices and farmers’ logic to explain actual drip irrigation performance

    NARCIS (Netherlands)

    Benouniche, M.; Kuper, M.; Hammani, A.; Boesveld, H.

    2014-01-01

    The actual performance of drip irrigation (irrigation efficiency, distribution uniformity) in the field is often quite different from that obtained in experimental stations. We developed an approach to explain the actual irrigation performance of drip irrigation systems by linking measured

  14. Trickle or clumped infection process? A stochastic model for the infection process of the parasitic roundworm of humans, Ascaris lumbricoides.

    Science.gov (United States)

    Walker, Martin; Hall, Andrew; Basáñez, María-Gloria

    2010-10-01

    The importance of the mode of acquisition of infectious stages of directly-transmitted parasitic helminths has been acknowledged in population dynamics models; hosts may acquire eggs/larvae singly in a "trickle" type manner or in "clumps". Such models have shown that the mode of acquisition influences the distribution and dynamics of parasite loads, the stability of host-parasite systems and the rate of emergence of anthelmintic resistance, yet very few field studies have allowed these questions to be explored with empirical data. We have analysed individual worm weight data for the parasitic roundworm of humans, Ascaris lumbricoides, collected from a three-round chemo-expulsion study in Dhaka, Bangladesh, with the aim of discerning whether a trickle or a clumped infection process predominates. We found that hosts tend to harbour female worms of a similar weight, indicative of a clumped infection process, but acknowledged that unmeasured host heterogeneities (random effects) could not be completely excluded as a cause. Here, we complement our previous statistical analyses using a stochastic infection model to simulate sizes of individual A. lumbricoides infecting a population of humans. We use the intraclass correlation coefficient (ICC) as a quantitative measure of similarity among simulated worm sizes and explore the behaviour of this statistic under assumptions corresponding to trickle or clumped infections and unmeasured host heterogeneities. We confirm that both mechanisms are capable of generating aggregates of similar-sized worms, but that the particular pattern of ICCs described pre- and post-anthelmintic treatment in the data is more consistent with aggregation generated by clumped infections than by host heterogeneities alone. This provides support to the notion that worms may be acquired in clumps. We discuss our results in terms of the population biology of A. lumbricoides and highlight the significance of our modelling approach for the study of the

  15. Sediment transport in irrigation canals

    OpenAIRE

    Méndez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high crop production. Irrigation has been the largest recipient of public agricultural investment in the developing world. Hence, continued investment in irrigation along with reforms in institutional a...

  16. Local liquid velocity measurement of Trickle Bed Reactor using Digital Industrial X-ray Radiography

    Science.gov (United States)

    Mohd Salleh, Khairul Anuar

    Trickle Bed Reactors (TBRs) are fixed beds of particles in which both liquid and gas flow concurrently downward. They are widely used to produce not only fuels but also lubrication products. The measurement and the knowledge of local liquid velocities (VLL) in TBRs is less which is essential for advancing the understanding of its hydrodynamics and for validation computational fluid dynamics (CFD). Therefore, this work focused on developing a new, non-invasive, statistically reliable technique that can be used to measure local liquid velocity (VLL) in two-dimensions (2-D). This is performed by combining Digital Industrial X-ray Radiography (DIR) and Particle Tracking Velocimetry (PTV) techniques. This work also make possible the development of three-dimensional (3-D) VLL measurements that can be taken in TBRs. Measurements taken through both the combined and the novel technique, once validated, were found to be comparable to another technique (a two-point fiber optical probe) currently being developed at Missouri University of Science and Technology. The results from this study indicate that, for a gas-liquid-solid type bed, the measured VLL can have a maximum range that is between 35 and 51 times that of its superficial liquid velocity (VSL). Without the existence of gas, the measured VLL can have a maximum range that is between 4 and 4.7 times that of its VSL. At a higher V SL, the particle tracer was greatly distributed and became carried away by a high liquid flow rate. Neither the variance nor the range of measured VLL varied for any of the replications, confirming the reproducibility of the experimental measurements used, regardless of the VSL . The liquid's movement inside the pore was consistent with findings from previous studies that used various techniques.

  17. ANALYSIS OF TRICKLE BED AND PACKED BUBBLE COLUMN BIOREACTORS FOR COMBINED CARBON OXIDATION AND NITRIFICATION

    Directory of Open Access Journals (Sweden)

    Iliuta I.

    2002-01-01

    Full Text Available Biological removal of nitrogen and carbon by combined nitrification-oxidation in gas-liquid trickle-bed reactors (TBRs and packed bubble columns (PBCs was analyzed theoretically using a transient two-dimensional model. The model describes TBR and PBC performances at steady state as well as their transient response to a pulse or step increase in inlet methanol and NH4+-nitrogen concentrations. The hydrodynamic parameters were determined from residence time distribution measurements, using an imperfect pulse method for time-domain analysis of nonideal pulse tracer response. A transient diffusion model of the tracer in the porous particle coupled with the piston-dispersion-exchange model was used to interpret the residence time distribution curves obtained. Gas-liquid mass transfer parameters were determined by a stationary method based on the least-squares fit of the calculated concentration profiles in gas phase to the experimental values. Analysis of steady-state performances showed that under like operating conditions, the TBR outperforms the PBC in terms of conversions. A pulse change in the inlet methanol or NH4+-nitrogen concentration causes a negligible transient change in the outlet methanol concentration and a negligible or high transient change in the outlet NH4+-nitrogen concentration. A step change in the inlet methanol concentration causes the negligible transient change in the methanol outlet concentration and a relatively important transient change in the NH4+-nitrogen outlet concentration. A step increase in the NH4+-nitrogen inlet concentration induces a drastic transient change in the NH4+-nitrogen outlet concentration but a negligible transient change in the methanol outlet concentration.

  18. Roughness and temperature effects on the filter media of a trickling filter for nitrification.

    Science.gov (United States)

    Kishimoto, Naoyuki; Ohara, Tetsuya; Hinobayashi, Jouji; Hashimoto, Tsutomu

    2014-01-01

    The performance of trickling filters using two types of plastic media with the same material, the same shape and different roughness was evaluated during a temperature-decreasing period to understand the roughness and temperature effects on the filter media. Real restaurant wastewater was used for the experiments. The chemical oxygen demand (COD) removal and nitrification performance of plastic media with a rough surface (LT-15) was superior to that with a smooth surface (KT-15). Because the biomass of microorganisms attached on the LT-15 was twice that attached on the KT-15, the larger biomass attached on the LT-15 was thought to be responsible for the higher performance. During the operation, the COD loading and water temperature varied in the range from 0.37 to 1.9 kg m(-3) d(-1) and 17.0--10.0 degrees C, respectively. However, the COD removal performance was not dependent on the COD loading or water temperature. On the contrary, the COD loading and the water temperature influenced the nitrification performance. Although a nitrification efficiency of 100% was recorded at a COD loading of 0.37 kg m(-3) d(-1), it deteriorated to 17-28% at higher COD loading. Moreover, a decline in the water temperature decreased the nitrification performance. The temperature-activity coefficient for nitrification was estimated to be 1.096. Based on this value, it was inferred that the COD loading should be set at less than 0.20 kg m(-3) d(-1) for the complete nitrification of the restaurant wastewater in winter, when the water temperature usually drops to around 10 degrees C.

  19. Laboratory-scale biofiltration of acrylonitrile by Rhodococcus rhodochrous DAP 96622 in a trickling bed bioreactor.

    Science.gov (United States)

    Zhang, Jie; Pierce, George E

    2009-07-01

    Acrylonitrile (ACN), a volatile component of the waste generated during the production of acrylamide, also is often associated with aromatic contaminants such as toluene and styrene. Biofiltration, considered an effective technique for the treatment of volatile hydrocarbons, has not been used to treat volatile nitriles. An experimental laboratory-scale trickling bed bioreactor using cells of Rhodococcus rhodochrous DAP 96622 supported on granular activated carbon (GAC) was developed and evaluated to assess the ability of biofiltration to treat ACN. In addition to following the course of treatability of ACN, kinetics of ACN biodegradation during both recycle batch and open modes of operation by immobilized and free cells were evaluated. For fed-batch mode bioreactor with immobilized cells, almost complete ACN removal (>95%) was achieved at a flow rate of 0.1 microl/min ACN and 0.8 microl/min toluene (TOL) (for comparative purposes this is equivalent to 6.9 mg l(-1) h(-1) ACN and 83.52 mg l(-1) h(-1) TOL). In a single-pass mode bioreactor with immobilized cells, at ACN inlet loads of 100-200 mg l(-1) h(-1) and TOL inlet load of approximately 400 mg l(-1) h(-1), with empty bed retention time (EBRT) of 8 min, ACN removal efficiency was approximately 90%. The three-dimensional structure and characteristics of the biofilm were investigated using confocal scanning laser microscopy (CSLM). CLSM images revealed a robust and heterogeneous biofilm, with microcolonies interspersed with voids and channels. Analysis of the precise measurement of biofilm characteristics using COMSTAT agreed with the assumption that both biomass and biofilm thickness increased along the carbon column depth.

  20. Effect of application rates and media types on nitrogen and surfactant removal in trickling filters applied to the post-treatment of effluents from UASB reactors

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, P. G. S. de; Taveres, F. v. F.; Chernicharo, C. A. I.

    2009-07-01

    Tricking filters are a very promising alternative for the post treatment of effluents from UASB reactors treating domestic sewage,especially in developing countries. Although a fair amount of information is already available regarding organic mater removal in this combined system, very little is known in relation to nitrogen and surfactant removal in trickling filters post-UASB reactors. Therefore, the purpose of this study was to evaluate and compare the effect evaluate and compare the effect of different application rates and packing media types on trickling filters applied to the post-treatment of effluents from UASB reactors, regarding the removal of ammonia nitrogen and surfactants. (Author)

  1. Irrigation trends in Kansas, 1991–2011

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This fact sheet examines trends in total reported irrigation water use and acres irrigated as well as irrigation water use by crop type and system type in Kansas for...

  2. Soil Water Distribution and Irrigation Uniformity Under Alternative Furrow Irrigation

    Institute of Scientific and Technical Information of China (English)

    PAN Ying-hua; KANG Shao-zhong; DU Tai-sheng; YANG Xiu-ying

    2003-01-01

    Field experiments were conducted to investigate the spatial-temporal distribution and the uni-formity of soil water under alternative furrow irrigation in spring maize field in Gansu Province. Resultsshowed that during the crop growing season, alternative drying and wetting furrows could incur crops to en-dure a water stress, thus the adsorptive ability of root system could be enhanced. As there was no zero fluxplane between irrigated furrows and non-irrigated furrows under alternative furrow irrigation, lateral infiltra-tion of water was obviously increased, thus decreasing the deep percolation. Compared with the conventionalirrigation, although the water consumption in alternative furrow irrigation was reduced, the uniformity of soilwater was not obviously affected.

  3. Irrigation management in organic greenhouse

    NARCIS (Netherlands)

    Voogt, W.; Balendonck, J.; Berkelmans, R.; Enthoven, N.

    2017-01-01

    Irrigation in protected cultivation is essential due to the absence of natural precipitation. High evapotranspiration, due to higher temperature and prolonged cropping period, requires ample an adequate supply of water. The water supply in a greenhouse is solely carried out by irrigation and thus

  4. CROP UNDER DEFICIT IRRIGATION SCHEDULING

    African Journals Online (AJOL)

    This study presents crop coefficient (Kc) values of TMV 1 -ST maize variety ... given time from planting to the time it is harvested. ... real time irrigation scheduling for high frequent and non-fiequent water .... 10 m, and the average soil bulk density was 1420 kg/m'. ...... Performance Evaluation of Fadama Irrigation Practice.

  5. Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum.

    Directory of Open Access Journals (Sweden)

    Yuan Li

    Full Text Available Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing, on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS and enlargement (58-85 DAS growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content, taste (titratable acidity, and market quality (shape and firmness of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

  6. Effect of Post-Infiltration Soil Aeration at Different Growth Stages on Growth and Fruit Quality of Drip-Irrigated Potted Tomato Plants (Solanum lycopersicum).

    Science.gov (United States)

    Li, Yuan; Jia, Zongxia; Niu, Wenquan; Wang, Jingwei; Zhang, Mingzhi

    2015-01-01

    Soil hydraulic principles suggest that post-infiltration hypoxic conditions would be induced in the plant root-zone for drip-irrigated tomato production in small pots filled with natural soil. No previous study specifically examined the response of tomato plants (Solanum lycopersicum) at different growth stages to low soil aeration under these conditions. A 2 × 6 factorial experiment was conducted to quantify effects of no post-infiltration soil aeration versus aeration during 5 different periods (namely 27-33, 34-57, 58-85, 86-99, and 27-99 days after sowing), on growth and fruit quality of potted single tomato plants that were sub-surface trickle-irrigated every 2 days at 2 levels. Soil was aerated by injecting 2.5 liters of air into each pot through the drip tubing immediately after irrigation. Results showed that post-infiltration aeration, especially during the fruit setting (34-57 DAS) and enlargement (58-85 DAS) growth stages, can positively influence the yield, root dry weight and activity, and the nutritional (soluble solids and vitamin C content), taste (titratable acidity), and market quality (shape and firmness) of the tomato fruits. Interactions between irrigation level and post-infiltration aeration on some of these fruit quality parameters indicated a need for further study on the dynamic interplay of air and water in the root zone of the plants under the conditions of this experiment.

  7. Sensing technologies for precision irrigation

    CERN Document Server

    Ćulibrk, Dubravko; Minic, Vladan; Alonso Fernandez, Marta; Alvarez Osuna, Javier; Crnojevic, Vladimir

    2014-01-01

    This brief provides an overview of state-of-the-art sensing technologies relevant to the problem of precision irrigation, an emerging field within the domain of precision agriculture. Applications of wireless sensor networks, satellite data and geographic information systems in the domain are covered. This brief presents the basic concepts of the technologies and emphasizes the practical aspects that enable the implementation of intelligent irrigation systems. The authors target a broad audience interested in this theme and organize the content in five chapters, each concerned with a specific technology needed to address the problem of optimal crop irrigation. Professionals and researchers will find the text a thorough survey with practical applications.

  8. Soil management and conservation: Irrigation: Methods

    Science.gov (United States)

    Irrigation applies water to soil to improve crop production. The three main methods of irrigation are surface, sprinkler and micro. Surface irrigation is used on 85% of the irrigated land in the world. It generally requires lower capital investment because the soil conveys water within the field, ra...

  9. Wireless sensor networks for irrigation management

    Science.gov (United States)

    Sustaining an adequate food supply for the world's population will require advancements in irrigation technology and improved irrigation management. Site-specific irrigation and automatic irrigation scheduling are examples of strategies to deal with declining arable land and limited fresh water reso...

  10. 76 FR 20971 - Turlock Irrigation District and Modesto Irrigation District; Notice of Intent To File License...

    Science.gov (United States)

    2011-04-14

    ... Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice of..., 2011. d. Submitted By: Turlock Irrigation District and Modesto Irrigation District. e. Name of Project... Regulatory Affairs, Turlock Irrigation District, P.O. Box 949, Turlock, California 95381, 209-883-8241...

  11. Irrigation Controllers Specification and Certification

    Science.gov (United States)

    WaterSense labeled irrigation controllers, which act like a thermostat for your sprinkler system telling it when to turn on and off, use local weather and landscape conditions to tailor watering schedules to actual conditions on the site.

  12. Irrigation Sprinklers Notice of Intent

    Science.gov (United States)

    High-efficiency irrigation sprinklers aim to deliver water more evenly to the landscape than traditional sprinklers and/or regulate outlet pressure to ensure a constant flow rate over a range of supply pressures.

  13. Dreams, themes and particle beams--an oncologist's perspective on technology trickle-down from the LHC.

    Science.gov (United States)

    Jena, R

    2014-04-01

    11 years ago, the European Network for Light Ion Therapy (ENLIGHT) was established as a multidisciplinary network of engineers, physicists and clinicians with a common interest in the development of hadron therapy in Europe. ENLIGHT is coordinated from the European Centre for Nuclear Research (CERN), the home of the Large Hadron Collider. The network has evolved into a mature platform for research, with more than 100 researchers working in CERN and its allied research centres. One of the benefits of hosting this network at CERN is the ability to translate hardware and software developments, originally developed in the High Energy Physics domain, into clinical applications. From the perspective of a clinical radiation oncologist within the network, this commentary reviews the ways in which leading edge technological developments in detectors and solid state physics, Monte-Carlo simulation, grid computing and accelerator design have trickled down into real-world clinical applications.

  14. Dreams, themes and particle beams—an oncologist's perspective on technology trickle-down from the LHC

    Science.gov (United States)

    2014-01-01

    11 years ago, the European Network for Light Ion Therapy (ENLIGHT) was established as a multidisciplinary network of engineers, physicists and clinicians with a common interest in the development of hadron therapy in Europe. ENLIGHT is coordinated from the European Centre for Nuclear Research (CERN), the home of the Large Hadron Collider. The network has evolved into a mature platform for research, with more than 100 researchers working in CERN and its allied research centres. One of the benefits of hosting this network at CERN is the ability to translate hardware and software developments, originally developed in the High Energy Physics domain, into clinical applications. From the perspective of a clinical radiation oncologist within the network, this commentary reviews the ways in which leading edge technological developments in detectors and solid state physics, Monte-Carlo simulation, grid computing and accelerator design have trickled down into real-world clinical applications. PMID:24593272

  15. Analysis of trickle-bed reactor for ethanol production from syngas using Clostridium ragsdalei

    Science.gov (United States)

    Devarapalli, Mamatha

    The conversion of syngas components (CO, CO2 and H2) to liquid fuels such as ethanol involves complex biochemical reactions catalyzed by a group of acetogens such as Clostridium ljungdahlii, Clostridium carboxidivorans and Clostridium ragsdalei. The low ethanol productivity in this process is associated with the low solubility of gaseous substrates CO and H2 in the fermentation medium. In the present study, a 1-L trickle-bed reactor (TBR) was analyzed to understand its capabilities to improve the mass transfer of syngas in fermentation medium. Further, semi-continuous and continuous syngas fermentations were performed using C. ragsdalei to evaluate the ability of the TBR for ethanol production. In the mass transfer studies, using 6-mm glass beads, it was found that the overall mass transfer coefficient (kLa/V L) increased with the increase in gas flow rate from 5.5 to 130.5 sccm. Further, an increase in the liquid flow rate in the TBR decreased the kLa/VL due to the increase in liquid hold up volume (VL) in the packing. The highest kLa/VL values of 421 h-1 and 178 h-1 were achieved at a gas flow rate of 130.5 sccm for 6-mm and 3-mm glass beads, respectively. Semi-continuous fermentations were performed with repetitive medium replacement in counter-current and co-current modes. In semi-continuous fermentations with syngas consisting of 38% CO, 5% N2, 28.5% CO2 and 28.5% H2 (by volume), the increase in H2 conversion (from 18 to 55%) and uptake (from 0.7 to 2.2 mmol/h) were observed. This increase was attributed to more cell attachment in the packing that reduced CO inhibition to hydrogenase along the column length and increased the H2 uptake. The maximum ethanol produced during counter-current and co-current modes were 3.0 g/L and 5.7 g/L, respectively. In continuous syngas fermentation, the TBR was operated at dilution rates between 0.006 h-1and 0.012 h -1 and gas flow rates between 1.5 sccm and 18.9 sccm. The highest ethanol concentration of 13 g/L was achieved at

  16. Swing Set Irrigation System

    Directory of Open Access Journals (Sweden)

    Ambe Verma

    2015-05-01

    Full Text Available ABSTRACT India is a vast country based on agriculture and irrigation is the most important factor for agriculture. In India there are many sources provide for irrigation. Every day new technologies are emerged in the world which brings a revolutionary change in the nature of this world. day by day the energy resources used by the large population of this world are coming on the last stage This project give the idea that how the other different form of energy can be used and implemented efficiently to overcome from this problem The aim of this project is to achieve the objective of energy lasting problem which is likely to be faced over in coming decades. Energy lasting is a big problem in India. This is faced by every people who live in the country. Swing energy is the form of energy. In this paper we have represented the methodology of swing energy using for rural area of application. This paper is all about Swing Set Water Pump in which the water pump will execute with the help of a swing set of canopy type. As we need a motor to operate the water pump but in this project we use the swing in the place of motor and we use oscillatory motion of swing in the place of rotating motion of a motor. Everybody has needed the energy at an increasing rate ever since he came on the Earth. Because of this lot of energy has been exhausted and wasted. All the member are dedicated the amount of their important time to participate in multiple meetings read and research for making the content to the report. We would especially like to thanks for the efficient condition of the entire Advisory member and their experiences. This study was initial and performed within the BUDDHA INSTITUTE OF TECHNOLOGY GIDA Gorakhpur the final report represents the labour and interest of the entire member working for this project. Finally we would like to thanks to all the member of our college workshop who helped us in manufacturing of this project model.

  17. 78 FR 3892 - Turlock Irrigation District and Modesto Irrigation District; Notice Clarifying Party Status

    Science.gov (United States)

    2013-01-17

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice Clarifying Party Status On January 9, 2013, the Modesto Irrigation District (Modesto) filed a motion...

  18. Significant impacts of irrigation water sources and methods on modeling irrigation effects in the ACME Land Model

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Guoyong; Leung, Lai-Yung; Huang, Maoyi

    2017-07-01

    An irrigation module that considers both irrigation water sources and irrigation methods has been incorporated into the ACME Land Model (ALM). Global numerical experiments were conducted to evaluate the impacts of irrigation water sources and irrigation methods on the simulated irrigation effects. All simulations shared the same irrigation soil moisture target constrained by a global census dataset of irrigation amounts. Irrigation has large impacts on terrestrial water balances especially in regions with extensive irrigation. Such effects depend on the irrigation water sources: surface-water-fed irrigation leads to decreases in runoff and water table depth, while groundwater-fed irrigation increases water table depth, with positive or negative effects on runoff depending on the pumping intensity. Irrigation effects also depend significantly on the irrigation methods. Flood irrigation applies water in large volumes within short durations, resulting in much larger impacts on runoff and water table depth than drip and sprinkler irrigations. Differentiating the irrigation water sources and methods is important not only for representing the distinct pathways of how irrigation influences the terrestrial water balances, but also for estimating irrigation water use efficiency. Specifically, groundwater pumping has lower irrigation water use efficiency due to enhanced recharge rates. Different irrigation methods also affect water use efficiency, with drip irrigation the most efficient followed by sprinkler and flood irrigation. Our results highlight the importance of explicitly accounting for irrigation sources and irrigation methods, which are the least understood and constrained aspects in modeling irrigation water demand, water scarcity and irrigation effects in Earth System Models.

  19. Freqüência de irrigação por gotejamento durante o estádio vegetativo do tomateiro para processamento industrial Drip irrigation frequency for processing tomatoes during vegetative growth stage

    Directory of Open Access Journals (Sweden)

    Waldir Aparecido Marouelli

    2005-07-01

    8 and 16 days intervals showed a rooting system about 10 cm deeper than those irrigated twice a day. Titratable acidity, total soluble solids content, and rotten fruit rate were not affected by irrigation frequency. For best tomato crop performance, irrigations during vegetative stage should be given at a 2-day frequency, which corresponds to a soil water tension of 17 kPa.

  20. Teaching transanal irrigation for functional bowel disorders.

    Science.gov (United States)

    Coggrave, Maureen; Norton, Christine

    Transanal irrigation of the bowel in the management of functional bowel disorders is currently receiving increased attention following the recent introduction of the Peristeen irrigation kit (Coloplast Ltd) in April 2007. Irrigation provides a welcome additional choice in the limited range of available interventions for the management of these patients. However, evidence to support clinical practice around irrigation is limited and nursing knowledge and experience of irrigation is only just developing. This paper reports a series of master classes conducted to support and develop the use of irrigation in the UK, and demonstrates the value of the master class as an educational tool when introducing a novel therapy.

  1. Irrigation in dose assessments models

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Barkefors, Catarina [Studsvik RadWaste AB, Nykoeping (Sweden)

    2004-05-01

    SKB has carried out several safety analyses for repositories for radioactive waste, one of which was SR 97, a multi-site study concerned with a future deep bedrock repository for high-level waste. In case of future releases due to unforeseen failure of the protective multiple barrier system, radionuclides may be transported with groundwater and may reach the biosphere. Assessments of doses have to be carried out with a long-term perspective. Specific models are therefore employed to estimate consequences to man. It has been determined that the main pathway for nuclides from groundwater or surface water to soil is via irrigation. Irrigation may cause contamination of crops directly by e.g. interception or rain-splash, and indirectly via root-uptake from contaminated soil. The exposed people are in many safety assessments assumed to be self-sufficient, i.e. their food is produced locally where the concentration of radionuclides may be the highest. Irrigation therefore plays an important role when estimating consequences. The present study is therefore concerned with a more extensive analysis of the role of irrigation for possible future doses to people living in the area surrounding a repository. Current irrigation practices in Sweden are summarised, showing that vegetables and potatoes are the most common crops for irrigation. In general, however, irrigation is not so common in Sweden. The irrigation model used in the latest assessments is described. A sensitivity analysis is performed showing that, as expected, interception of irrigation water and retention on vegetation surfaces are important parameters. The parameters used to describe this are discussed. A summary is also given how irrigation is proposed to be handled in the international BIOMASS (BIOsphere Modelling and ASSessment) project and in models like TAME and BIOTRAC. Similarities and differences are pointed out. Some numerical results are presented showing that surface contamination in general gives the

  2. Controlled biomass formation and kinetics of toluene degradation in a bioscrubber and in a reactor with a periodically moved trickle-bed.

    Science.gov (United States)

    Wübker, S M; Laurenzis, A; Werner, U; Friedrich, C

    1997-08-20

    The kinetics of degradation of toluene from a model waste gas and of biomass formation were examined in a bioscrubber operated under different nutrient limitations with a mixed culture. The applicability of the kinetics of continuous cultivation of the mixed culture was examined for a special trickle-bed reactor with a periodically moved filter bed. The efficiency of toluene elimination of the bioscrubber was 50 to 57% and depended on the toluene mass transfer as evident from a constant productivity of 0.026 g dry cell weight/L . h over the dilution rate. Under potassium limitation the biomass productivity was reduced by 60% to 0.011 g dry cell weight/L . h at a dilution rate of 0.013/h. Conversely, at low dilution rates the specific toluene degradation rates increased. Excess biomass in a trickle-bed reactor causes reduction of interfacial area and mass transfer, and increase in pressure drop. To avoid these disadvantages, the trickle-bed was moved periodically and biomass was removed with outflowing medium. The concentration of steady state biomass fixed on polyamide beads decreased hyperbolically with the dilution rate. Also, the efficiency of toluene degradation decreased from 72 to 56% with increasing dilution rate while the productivity increased. Potassium limitation generally caused a reduction in biomass, productivity, and yield while the specific degradation increased with dilution rate. This allowed the application of the principles of the chemostat to the trickle-bed reactor described here, for toluene degradation from waste gases. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 686-692, 1997.

  3. Estimating actual irrigation application by remotely sensed evapotranspiration observations

    NARCIS (Netherlands)

    Droogers, P.; Immerzeel, W.W.; Lorite, I.J.; SWAP, PEST

    2010-01-01

    Water managers and policy makers need accurate estimates of real (actual) irrigation applications for effective monitoring of irrigation and efficient irrigation management. However, this information is not readily available at field level for larger irrigation areas. An innovative inverse modeling

  4. Sustainable irrigation in fruit trees

    Directory of Open Access Journals (Sweden)

    Cristos Xiloyannis

    Full Text Available Water management in fruit growing, particularly in areas with high water deficit, low rainfall and limited availability of water for irrigation should aid to save water by: i the choice of high efficiency irrigation methods and their correct management; ii the proper choice of the specie, cultivar and rootstock to optimise plant water use; iii the proper choice of the architecture of the canopy and it’s correct management in order to improve water use efficiency; iv the application of regulated deficit irrigation at growth stages less sensitive to water deficit; v strengthening the role of technical assistance for a rapid transfer of knowledge to the growers on the sustainable use of water in fruit growing.

  5. AGROCLIMATIC DETERMINANTS OF IRRIGATION NEEDS

    Directory of Open Access Journals (Sweden)

    Leszek Łabędzki

    2016-05-01

    Full Text Available The paper is a review of the so far used in Poland methods and criteria for assessing the needs of irrigation for planning purposes, the assessment because of the agroclimatic conditions and taking into account the soil water retention. Irrigation needs of the most are determined taking into account crop water deficits. This is the factor that is characterized by a shortage of precipitation in relation to the water requirements of crops. Some methods use only the meteorological parameters that determine the state of the atmosphere-soil-plant system, and some also take into account soil water retention and its availability for plants.

  6. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  7. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  8. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands

  9. 75 FR 43958 - Turlock Irrigation District and Modesto Irrigation District; Notice of Application for Amendment...

    Science.gov (United States)

    2010-07-27

    ... Energy Regulatory Commission Turlock Irrigation District and Modesto Irrigation District; Notice of...: May 24, 2010. d. Applicant: Turlock Irrigation District and Modesto Irrigation District. e. Name of.... g. Filed Pursuant to: Federal Power Act, 16 USC 791a-825r. h. Applicant Contact: Turlock...

  10. Cotton irrigation timing with variable seasonal irrigation capacities in the Texas south plains.

    Science.gov (United States)

    Within the Ogallala Aquifer Region of Texas, the irrigation capacity (IC) for a given field often changes within a growing season due to seasonal depletion of the aquifer, in season changes in crop irrigation needs in dry years, or consequences of irrigation volume limits imposed by irrigation distr...

  11. 75 FR 35778 - Modesto Irrigation District and Turlock Irrigation District; Notice of Preliminary Permit...

    Science.gov (United States)

    2010-06-23

    ... Energy Regulatory Commission Modesto Irrigation District and Turlock Irrigation District; Notice of... Competing Applications June 16, 2010. On February 1, 2010, Modesto Irrigation District and Turlock Irrigation District filed an application for a preliminary permit, pursuant to section 4(f) of the...

  12. SURDEV: surface irrigation software; design, operation, and evaluation of basin, border, and furrow irrigation

    NARCIS (Netherlands)

    Jurriëns, M.; Zerihun, D.; Boonstra, J.; Feyen, J.

    2001-01-01

    SURDEV is a computer package for the design, operation, and evaluation of surface irrigation. SURDEV combines three sub-programs: BASDEV (for basin irrigation), FURDEV (for furrow irrigation), and BORDEV for (border irrigation). This combination enables the user to simulate many of the problems invo

  13. Modernisation Strategy for National Irrigation Systems in the Philippines: Balanac and Sta. Maria River Irrigation Systems

    NARCIS (Netherlands)

    Delos Reyes, M.L.F.

    2017-01-01

    This book examines the nature and impact of irrigation system rehabilitation on increasing the actual area irrigated by the publicly funded canal irrigation systems of the Philippines. It proposes a system diagnosis approach for the development of a more appropriate and climate-smart irrigation

  14. SURDEV: surface irrigation software; design, operation, and evaluation of basin, border, and furrow irrigation

    NARCIS (Netherlands)

    Jurriëns, M.; Zerihun, D.; Boonstra, J.; Feyen, J.

    2001-01-01

    SURDEV is a computer package for the design, operation, and evaluation of surface irrigation. SURDEV combines three sub-programs: BASDEV (for basin irrigation), FURDEV (for furrow irrigation), and BORDEV for (border irrigation). This combination enables the user to simulate many of the problems

  15. Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district

    NARCIS (Netherlands)

    Urrutia Cobo, N.

    2006-01-01

    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands locat

  16. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  17. Sediment transport in irrigation canals.

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to effect high

  18. Sediment transport in irrigation canals

    NARCIS (Netherlands)

    Mendez V., N.J.

    1998-01-01

    The world population is rapidly increasing and is expected to double to about 10 billion by the year 2050. To support an increasing population in terms of food sufficiency, more and more water will be required. Irrigation is the most critical component of the modern package of inputs to

  19. Position paper : Whole bowel irrigation

    NARCIS (Netherlands)

    2004-01-01

    Whole bowel irrigation (WBI) should not be used routinely in the management of the poisoned patient. Although some volunteer studies have shown substantial decreases in the bioavailability of ingested drugs, no controlled clinical trials have been performed and there is no conclusive evidence that W

  20. Agricultural growth and "trickle-down" reconsidered: evidence from rural India.

    Science.gov (United States)

    Sharma, S D

    1997-08-01

    This examination of the "green revolution" in India considers the totality of State-guided development strategies on the lives of ordinary people through an analysis of data collected during field work in 1990-91, 1993-94, and 1995 in a typical north Indian village. The first part of the report situates the "green revolution" strategy in its larger political-economic context, reviewing the circumstances under which it was launched, the nature of the implementation process, and macrolevel trends. After this introduction, the paper presents the village case study with a description of the physical attributes of the village, its social composition, and patterns of land tenure. This highlights the fact that the larger land-owing interests have been the primary beneficiaries of the "green revolution." Wealthy land-owners have been able to diversify their income sources through the purchase of threshing machinery for their own use and for rental to others, the construction of storage facilities where grain can be withheld until top prices are offered in the market, the processing of sugar cane, and dairy farming. Farmers owning less than 1.5 hectares of irrigated land, however lack the resource base to invest in new agricultural technologies. They either go in debt (with little hope of ever producing enough to eliminate the need for borrowing) to purchase the higher-yielding seeds, fertilizers, and chemical pesticides required by the new methods or they retreat into subsistence farming and hire themselves out as labor. This strategy is seldom resorted to, however, because of the pressures of meeting minimal subsistence needs in a cash economy. The top-down strategies that accompanied agricultural modernization have led to a deterioration in the standard of living of the poor. In addition, the "green revolution" is environmentally unsustainable and, ultimately, will have tragic ramifications for India.

  1. A comparison of mass transfer coefficients between trickle-bed, hollow fiber membrane and stirred tank reactors.

    Science.gov (United States)

    Orgill, James J; Atiyeh, Hasan K; Devarapalli, Mamatha; Phillips, John R; Lewis, Randy S; Huhnke, Raymond L

    2013-04-01

    Trickle-bed reactor (TBR), hollow fiber membrane reactor (HFR) and stirred tank reactor (STR) can be used in fermentation of sparingly soluble gasses such as CO and H2 to produce biofuels and bio-based chemicals. Gas fermenting reactors must provide high mass transfer capabilities that match the kinetic requirements of the microorganisms used. The present study compared the volumetric mass transfer coefficient (K(tot)A/V(L)) of three reactor types; the TBR with 3 mm and 6 mm beads, five different modules of HFRs, and the STR. The analysis was performed using O2 as the gaseous mass transfer agent. The non-porous polydimethylsiloxane (PDMS) HFR provided the highest K(tot)A/V(L) (1062 h(-1)), followed by the TBR with 6mm beads (421 h(-1)), and then the STR (114 h(-1)). The mass transfer characteristics in each reactor were affected by agitation speed, and gas and liquid flow rates. Furthermore, issues regarding the comparison of mass transfer coefficients are discussed.

  2. Performance and population analysis of a non-sterile trickle bed reactor inoculated with Caldicellulosiruptor saccharolyticus, a thermophilic hydrogen producer

    Energy Technology Data Exchange (ETDEWEB)

    Van Groenestijn, J.W.; Meesters, K.P.M. [TNO Quality of Life, P.O. Box 360, 3700 AJ Zeist (Netherlands); Geelhoed, J.S.; Goorissen, H.P.; Stams, A.J.M. [Laboratory of Microbiology, Wageningen University, Dreijenplein, Wageningen (Netherlands); Claassen, P.A.M. [Wageningen UR, Agrotechnology and Food Sciences Group (Netherlands)

    2009-04-01

    Non-axenic operation of a 400 L trickle bed reactor inoculated with the thermophile Caldicellulosiruptor saccharolyticus, yielded 2.8 mol/H2/mol hexose converted. The reactor was fed with a complex medium with sucrose as the main substrate, continuously flushed with nitrogen gas, and operated at 73C. The volumetric productivity was 22 mmol/H2/(L filterbed h). Acetic acid and lactic acid were the main by-products in the liquid phase. Production of lactic acid occurred when hydrogen partial pressure was elevated above 2% and during suboptimal fermentation conditions that also resulted in the presence of mono- and disaccharides in the effluent. Methane production was negligible. The microbial community was analyzed at two different time points during operation. Initially, other species related to members of the genera Thermoanaerobacterium and Caldicellulosiruptor were present in the reactor. However, these were out-competed by C. saccharolyticus during a period when sucrose was completely used and no saccharides were discharged with the effluent. In general, the use of pure cultures in non-sterile industrial applications is known to be less useful because of contamination. However, our results show that the applied fermentation conditions resulted in a culture of a single dominant organism with excellent hydrogen production characteristics.

  3. A two-stage combined trickle bed reactor/biofilter for treatment of styrene/acetone vapor mixtures.

    Science.gov (United States)

    Vanek, Tomas; Halecky, Martin; Paca, Jan; Zapotocky, Lubos; Gelbicova, Tereza; Vadkertiova, Renata; Kozliak, Evguenii; Jones, Kim

    2015-01-01

    Performance of a two-stage biofiltration system was investigated for removal of styrene-acetone mixtures. High steady-state acetone loadings (above C(in)(Ac) = 0.5 g.m(-3) corresponding to the loadings > 34.5 g.m(-3).h(-1)) resulted in a significant inhibition of the system's performance in both acetone and styrene removal. This inhibition was shown to result from the acetone accumulation within the upstream trickle-bed bioreactor (TBR) circulating mineral medium, which was observed by direct chromatographic measurements. Placing a biofilter (BF) downstream to this TBR overcomes the inhibition as long as the biofilter has a sufficient bed height. A different kind of inhibition of styrene biodegradation was observed within the biofilter at very high acetone loadings (above C(in)(Ac) = 1.1 g.m(-3) or 76 g.m(-3).h(-1) loading). In addition to steady-state measurements, dynamic tests confirmed that the reactor overloading can be readily overcome, once the accumulated acetone in the TBR fluids is degraded. No sizable metabolite accumulation in the medium was observed for either TBR or BF. Analyses of the biodegradation activities of microbial isolates from the biofilm corroborated the trends observed for the two-stage biofiltration system, particularly the occurrence of an inhibition threshold by excess acetone.

  4. Improvement of trickling biofilter purification performance on treating chlorobenzene in waste gases using surfactant%用表面活性剂提高生物滴滤床净化废气中氯苯的性能

    Institute of Scientific and Technical Information of China (English)

    刘强; 邓瑜衡

    2007-01-01

    A laboratory-scale trickling biofilter column, filled with Raschig rings and inoculated with Pseudomonas putida(ATCC 1785) was used to purify chlorobenzene contained waste gases. Sodium dodecyl sulfonate (SDS) was used to enhance the performance of trickling biofilter. Purification performance of the trickling biofilter was examined for chlorobenzene inlet concentration of 1.20~5.04 g/ms at different EBRTs between 76~153 s. Without SDS addition, with simultaneous increase in chlorobenzene inlet loading rate and gas flow rate, 100% removal efficiency was achieved at EBRT of 109 s and inlet loadings below 5120 mg/m3. Addition of SDS to nutrient solution led to improvement of trickling biofilter purification performance.By introducing 25 mg/L SDS, the removal efficiency was increased by 21% and elimination capacity up to 234 g/(m3·h) was achieved at chlorobenzene inlet olading of 241 g/(m3·h).Although SDS concentration experienced a low rate reduction after continuous nutrient solution recirculation, this result has little influence on trickling biofilter's removal efficiency in monitoring period.

  5. A Fuzzy Control Irrigation System For Cottonfield

    Science.gov (United States)

    Zhang, Jun; Zhao, Yandong; Wang, Yiming; Li, Jinping

    A fuzzy control irrigation system for cotton field is presented in this paper. The system is composed of host computer, slave computer controller, communication module, soil water sensors, valve controllers, and system software. A fuzzy control model is constructed to control the irrigation time and irrigation quantity for cotton filed. According to the water-required rules of different cotton growing periods, different irrigation strategies can be carried out automatically. This system had been used for precision irrigation of the cotton field in Langfang experimental farm of Soil and Fertilizer Institute, Chinese Academy of Agricultural Sciences in 2006. The results show that the fuzzy control irrigation system can improve cotton yield and save much water quantity than the irrigation system based on simple on-off control algorithm.

  6. Present-day irrigation mitigates heat extremes

    Science.gov (United States)

    Thiery, Wim; Davin, Edouard L.; Lawrence, David M.; Hirsch, Annette L.; Hauser, Mathias; Seneviratne, Sonia I.

    2017-02-01

    Irrigation is an essential practice for sustaining global food production and many regional economies. Emerging scientific evidence indicates that irrigation substantially affects mean climate conditions in different regions of the world. Yet how this practice influences climate extremes is currently unknown. Here we use ensemble simulations with the Community Earth System Model to assess the impacts of irrigation on climate extremes. An evaluation of the model performance reveals that irrigation has a small yet overall beneficial effect on the representation of present-day near-surface climate. While the influence of irrigation on annual mean temperatures is limited, we find a large impact on temperature extremes, with a particularly strong cooling during the hottest day of the year (-0.78 K averaged over irrigated land). The strong influence on extremes stems from the timing of irrigation and its influence on land-atmosphere coupling strength. Together these effects result in asymmetric temperature responses, with a more pronounced cooling during hot and/or dry periods. The influence of irrigation is even more pronounced when considering subgrid-scale model output, suggesting that local effects of land management are far more important than previously thought. Our results underline that irrigation has substantially reduced our exposure to hot temperature extremes in the past and highlight the need to account for irrigation in future climate projections.

  7. IRRIGATION OF ORNAMENTAL PLANT NURSERY

    Directory of Open Access Journals (Sweden)

    Eduardo de Aguiar do Couto

    2013-01-01

    Full Text Available Airports consume significant amounts of water which can be compared to the volume consumed by mid-size cities, thus practices aimed at reducing water consumption are important and necessar y. The objective of this study was to assess the reuse potential of sewage effluent produced at a mid-size international airport for nursery irri gation. The sewage treatment system consisted of a facultative pond followed by a constructed wetland, which were monitored during one hydrological year a nd the parameters COD, pH, solids, nitrogen, phosphorus and Escherichia coli we re analyzed. Removal efficiencies of 85% and 91% were achieved for C OD and solids, respectively. Removal efficiencies for ammonia nitrogen a nd total phosphorus were 77% and 59%, respectively. In terms of E. coli concen tration, the treated effluent met the recommendations by the World Health Organization for reuse in irrigation with the advantage of providing high levels of residual nutrient. The ornamental species Impatiens walleriana was irrigated with treated sewage effluent and plant growth characteristics were evalua ted. The experiment showed that reuse can enhance plant growth without signi ficantly affecting leaf tissue and soil characteristics. This study highlighted th e importance of simple technologies for sewage treatment especially in count ries which still do not present great investment in sanitation and proved that effluent reuse for landscape irrigation can provide great savings of water and financial resources for airport environments.

  8. Effects of Irrigation in India on the Atmospheric Water Budget

    NARCIS (Netherlands)

    Tuinenburg, O.A.; Hutjes, R.W.A.; Stacke, T.; Wiltshire, A.; Lucas-Picher, P.

    2014-01-01

    The effect of large-scale irrigation in India on the moisture budget of the atmosphere was investigated using three regional climate models and one global climate model, all of which performed an irrigated run and a natural run without irrigation. Using a common irrigation map, year-round irrigation

  9. X-ray digital industrial radiography (DIR) for local liquid velocity (VLL) measurement in trickle bed reactors (TBRs): Validation of the technique

    Science.gov (United States)

    Mohd Salleh, Khairul Anuar; Rahman, Mohd Fitri Abdul; Lee, Hyoung Koo; Al Dahhan, Muthanna H.

    2014-06-01

    Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (VLL) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure the VLL within TBRs.

  10. Local liquid velocity measurement in trickle bed reactors (TBRs) using the x-ray digital industrial radiography (DIR) technique

    Science.gov (United States)

    Anuar Mohd Salleh, Khairul; Lee, Hyoung Koo; Al-Dahhan, Muthanna H.

    2014-01-01

    This work describes the development of a new technique to measure local liquid velocity (VLL) for multiphase flows in trickle bed reactors (TBRs) (gas-liquid-solid system). In the studied TBR, the liquid phase is represented by water, gas by air and 3 mm expanded polystyrene beads as the solid packing. Three different superficial liquid velocities (VSL) and a constant superficial gas velocity (VSG) were used in the packed bed with an internal diameter of 4.25 cm. While the liquid is moving into the packed bed, tracking particles of 106-125 μm diameter (16.45% difference) are injected. The movement of the tracking particles is monitored and digitally recorded by a complementary metal-oxide-semiconductor detector. In this experiment, x-rays were used as the radiation source. Four replications were made with fresh packing. Comparable observations can be found from other published techniques (i.e. magnetic resonance imaging). Results from this study indicate that, at VSL = 0.13 cm s-1, the measured VLL can reach up to 51 times that of its VSL, while for VSL = 0.27 cm s-1, the measured VLL reached up to 35 times higher than the VSL and for VSL = 0.39 cm s-1, the VLL reached up to 39.8 times higher than its VSL. Through statistical analysis, the implementation of such a method is found to be reproducible throughout the experiments. The mean per cent difference in the measured VLL was 10% and 5% for lower implemented VSL of 0.13 and 0.27 cm s-1, respectively. At higher VSL (0.39 cm s-1), the particle tracer was greatly distributed and carried away by the high liquid flow rate. The variance or the range of the measured VLL does not vary for all replications in every VSL, which confirms the reproducibility of the experimental measurements, regardless of the VSL.

  11. Evaluation program for secondary spacecraft cells: Evaluation of storage methods, open circuit versus continuous trickle charge, Sonotone 3.5 ampere-hour sealed nickel-cadmium secondary spacecraft cells

    Science.gov (United States)

    Thomas, R. E.

    1972-01-01

    Twenty-five cells were used in a five-year test to compare, after each successive one-year storage period, the discharge and charge characteristics of charged cells on open circuit versus that of cells on continuous trickle charge. The test procedure, instrumentation, and results are described. Based on the test results, the following recommendations were made: (1) If the user's purpose will allow a rejuvenation cycle or two after a long storage period, the open circuit regime will likely give slightly greater capacity. (2) If the user's purpose demands immediately available power following a long storage period, the trickle charge method of storage is definitely the regime to use.

  12. Senegal - Irrigation and Water Resource Management

    Data.gov (United States)

    Millennium Challenge Corporation — IMPAQ: This evaluation report presents findings from the baseline data collected for the Irrigation and Water Resources Management (IWRM) project, which serves as...

  13. Automation of irrigation systems to control irrigation applications and crop water use efficiency

    Science.gov (United States)

    Agricultural irrigation management to slow water withdrawals from non-replenishing quality water resources is a global endeavor and vital to sustaining irrigated agriculture and dependent rural economies. Research in site-specific irrigation management has shown that water use efficiency, and crop p...

  14. 78 FR 37538 - Idaho Irrigation District; New Sweden Irrigation District; Notice of Preliminary Permit...

    Science.gov (United States)

    2013-06-21

    ... Energy Regulatory Commission Idaho Irrigation District; New Sweden Irrigation District; Notice of... Competing Applications On April 19, 2013, the Idaho and New Sweden Irrigation Districts, filed a joint... Street, Idaho Falls, Idaho 83404; phone: (208) 522-2356. Mr. Louis Thiel, Chairman, New Sweden...

  15. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Ken

  16. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; Sluis, van der L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  17. The simulation of cropping pattern to improve the performance of irrigation network in Cau irrigation area

    Science.gov (United States)

    Wahyuningsih, Retno; Rintis Hadiani, RR; Sobriyah

    2017-01-01

    Cau irrigation area located in Madiun district, East Java Province, irrigates 1.232 Ha of land which covers Cau primary channel irrigation network, Wungu Secondary channel irrigation network, and Grape secondary channel irrigation network. The problems in Cau irrigation area are limited availability of water especially during the dry season (planting season II and III) and non-compliance to cropping patterns. The evaluation of irrigation system performance of Cau irrigation area needs to be done in order to know how far the irrigation system performance is, especially based on planting productivity aspect. The improvement of irrigation network performance through cropping pattern optimization is based on the increase of water necessity fulfillment (k factor), the realization of planting area and rice productivity. The research method of irrigation system performance is by analyzing the secondary data based on the Regulation of Ministry of Public Work and State Minister for Public Housing Number: 12/PRT/M/2015. The analysis of water necessity fulfillment (k factor) uses Public Work Plan Criteria Method. The performance level of planting productivity aspect in existing condition is 87.10%, alternative 1 is 93.90% dan alternative 2 is 96.90%. It means that the performance of the irrigation network from productivity aspect increases 6.80% for alternative 1 and 9.80% for alternative 2.

  18. Factors affecting irrigant extrusion during root canal irrigation: a systematic review

    NARCIS (Netherlands)

    Boutsioukis, C.; Psimma, Z.; van der Sluis, L.W.M.

    2013-01-01

    The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted

  19. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    NARCIS (Netherlands)

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since

  20. 77 FR 16828 - Turlock Irrigation District, & Modesto Irrigation District; Notice of Dispute Resolution Process...

    Science.gov (United States)

    2012-03-22

    ... Energy Regulatory Commission Turlock Irrigation District, & Modesto Irrigation District; Notice of... and the Modesto Irrigation District (collectively, the Districts), are co-licensees for the Don Pedro... Steelhead Full Life-Cycle Population Models; and Request 9--Effects of the Project and Related Facilities on...

  1. Irrigation-based livelihood trends in river basins: theory and policy implications for irrigation development

    Science.gov (United States)

    Lankford, Bruce

    This paper examines irrigation development and policy in Tanzania utilising a livelihoods and river basin perspective. On the basis of observations, the author argues that river basins theoretically exhibit a sigmoid curve of irrigation development in three stages; proto-irrigation, irrigation-momentum and river basin management. This model arises from two governing factors. Firstly, irrigation is a complex livelihood activity that, although has benefits, also has costs, risks and alternatives that integrate across many systems; farmers implicitly understand this and enter into or keep out of irrigation accordingly. In the proto-irrigation stage, irrigators are less common, and irrigation is felt to be a relatively unattractive livelihood. In the irrigation-momentum stage, irrigators are drawn very much to irrigation in providing livelihood needs. Hence, given both of these circumstances, governments should be cautious about policies that call for the need to ‘provide irrigation’ (when farmers may not wish to irrigate) or to further increase it (when farmers already have the means and will to do so). Second, irrigation consumes water, generating externalities. Thus if irrigation momentum proceeds to the point when water consumption directly impacts on other sectors and livelihoods, (e.g. pastoralists, downstream irrigation, the environment) decision-makers should focus not necessarily on irrigation expansion, but on water management, allocation and conflict mediation. This three-stage theoretical model reminds us to take a balanced ‘livelihoods river-basin’ approach that addresses real problems in each given stage of river basin development and to develop policy accordingly. The paper contains a discussion on livelihood factors that affect entry into irrigation. It ends with a series of recommendations on policy; covering for example new large-scale systems; problems solving; and the use of an irrigation-river basin livelihoods approach. The recommendations

  2. Irrigation as an Historical Climate Forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2014-01-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  3. Irrigation as an historical climate forcing

    Science.gov (United States)

    Cook, Benjamin I.; Shukla, Sonali P.; Puma, Michael J.; Nazarenko, Larissa S.

    2015-03-01

    Irrigation is the single largest anthropogenic water use, a modification of the land surface that significantly affects surface energy budgets, the water cycle, and climate. Irrigation, however, is typically not included in standard historical general circulation model (GCM) simulations along with other anthropogenic and natural forcings. To investigate the importance of irrigation as an anthropogenic climate forcing, we conduct two 5-member ensemble GCM experiments. Both are setup identical to the historical forced (anthropogenic plus natural) scenario used in version 5 of the Coupled Model Intercomparison Project, but in one experiment we also add water to the land surface using a dataset of historically estimated irrigation rates. Irrigation has a negligible effect on the global average radiative balance at the top of the atmosphere, but causes significant cooling of global average surface air temperatures over land and dampens regional warming trends. This cooling is regionally focused and is especially strong in Western North America, the Mediterranean, the Middle East, and Asia. Irrigation enhances cloud cover and precipitation in these same regions, except for summer in parts of Monsoon Asia, where irrigation causes a reduction in monsoon season precipitation. Irrigation cools the surface, reducing upward fluxes of longwave radiation (increasing net longwave), and increases cloud cover, enhancing shortwave reflection (reducing net shortwave). The relative magnitude of these two processes causes regional increases (northern India) or decreases (Central Asia, China) in energy availability at the surface and top of the atmosphere. Despite these changes in net radiation, however, climate responses are due primarily to larger magnitude shifts in the Bowen ratio from sensible to latent heating. Irrigation impacts on temperature, precipitation, and other climate variables are regionally significant, even while other anthropogenic forcings (anthropogenic aerosols

  4. Efficacy of repeated trickle applications of oxalic acid in syrup for varroosis control in Apis mellifera: influence of meteorological conditions and presence of brood.

    Science.gov (United States)

    Bacandritsos, Nicolaos; Papanastasiou, Iosif; Saitanis, Costas; Nanetti, Antonio; Roinioti, Erifylli

    2007-09-01

    Oxalic acid field trails for the control of varroosis (Varroa destructor) were carried out in an apiary located on the Mt. Imittos (Attica, Greece). The colonies received four successive applications (approximately one every 16 days) with 4.2% oxalic acid (OA) and 60% sugar solution by trickling method with two alternative types of syringes (an automatic self-filling dosing and a single-use) from the broodright to broodless period. The results indicate that the first three applications (from 6th October to 25th November-broodright period) resulted in 65.3% cumulative mite mortality, while only the last application (after the 26th November-broodless period) resulted in 77.3% mite mortality. Very low outern temperatures reduce to the minimum the bee movability, which may result into a slower development of the OA efficacy. No poor colony growth or queen loss were observed even if the bee colonies were received the four successive OA applications with the last one taken place at a very low outern temperature (6.2 degrees C). The trickling method using an automatic-filling syringe seems to be a very quick way for applying oxalic acid in large apiaries (approximately 150hives/h).

  5. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Directory of Open Access Journals (Sweden)

    A. D. Chukalla

    2015-07-01

    Full Text Available Consumptive water footprint (WF reduction in irrigated crop production is essential given the increasing competition for fresh water. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET and yield (Y and thus the consumptive WF of crops (ET/Y. The management practices are: four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD; four irrigation strategies (full (FI, deficit (DI, supplementary (SI and no irrigation; and three mulching practices (no mulching, organic (OML and synthetic (SML mulching. Various cases were considered: arid, semi-arid, sub-humid and humid environments; wet, normal and dry years; three soil types; and three crops. The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching. The average reduction in the consumptive WF is: 8–10 % if we change from the reference to drip or SSD; 13 % when changing to OML; 17–18 % when moving to drip or SSD in combination with OML; and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

  6. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  7. Identifying the potential for irrigation development in Mozambique: Capitalizing on the drivers behind farmer-led irrigation expansion

    NARCIS (Netherlands)

    Beekman, P.W.; Veldwisch, G.J.A.; Bolding, J.A.

    2014-01-01

    Smallholder irrigation in Central Mozambique predominantly takes place in an informal setting. This renders these smallholders and their activities invisible for policy purposes. Identification efforts of smallholder irrigation as well as the potential for new irrigation development are often the

  8. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen

    2012-01-01

    Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

  9. A scintigraphic study of colostomy irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Shinji; Fujii, Hisao; Nakano, Hiroshige (Nara Medical Univ., Kashihara (Japan))

    1991-09-01

    Colostomy irrigation was investigated by colonoscintigraphy. Twelve rectal cancer and one sigmoid colon cancer patients were examined. The tepid water whose volume was determined by barium enema was mixed with {sup 99m}Tc-DTPA. Dynamic scanning was started on commencement of colostomy irrigation. The sampling time was 3 seconds and scanning was performed for 30 minutes. The mean volume of remnant colon as measured by barium enema was 650 ml. The mean number of mass movements was 4.3. The mean evacuation time was 11 minutes 56 seconds and the mean half emptying time was calculated to be 9.5 minutes. The evacuation time in the patients who underwent colostomy irrigation for more than 2 years was greater than that in the patients who underwent irrigation for less than 2 years. Colonic motility was thought to have weakened. The half emptying time and the number of mass movements in the patients whose irrigation water went into the terminal ileum was more than that in the patients whose irrigation water was within the colon and cecum. Irrigation water which went into the terminal ileum was caused evacuation after the contents of the remnant colon were washed out. In conclusion, patients should have their colostomy irrigated with the tepid water, volume is determined by barium enema. Furthermore single infusion of the water is recommended. (author).

  10. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    C. Boutsioukis; L.W.M. van der Sluis

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  11. Syringe irrigation: blending endodontics and fluid dynamics

    NARCIS (Netherlands)

    Boutsioukis, C.; van der Sluis, L.W.M.; Basrani, B.

    2015-01-01

    Syringe irrigation remains a widely used irrigant delivery method during root canal treatment. An interdisciplinary approach involving well-established methods from the field of fluid dynamics can provide new insights into the mechanisms involved in cleaning and disinfection of the root canal system

  12. Using Automation to Improve Surface Irrigation Management

    Science.gov (United States)

    In the Lower Mississippi Water Resource Area (WRA 08), also called the Mid-South, 2 million ha of cropland (80% of the irrigated farmland) employ surface irrigation, almost equally divided between furrow (52%) and controlled flooding (48%). Because Mid-South farmers experience less-than-optimal surf...

  13. Soil Enzyme Activities with Greenhouse Subsurface Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-Long; WANG Yao-Sheng

    2006-01-01

    Various environmental conditions determine soil enzyme activities, which are important indicators for changes of soil microbial activity, soil fertility, and land quality. The effect of subsurface irrigation scheduling on activities of three soil enzymes (phosphatase, urease, and catalase) was studied at five depths (0-10, 10-20, 20-30, 30-40, and 40-60 cm) of a tomato greenhouse soil. Irrigation was scheduled when soil water condition reached the maximum allowable depletion(MAD) designed for different treatments (-10, -16, -25, -40, and -63 kPa). Results showed that soil enzyme activities had significant responses to the irrigation scheduling during the period of subsurface irrigation. The neutral phosphatase activity and the catalase activity were found to generally increase with more frequent irrigation (MAD of -10 and -16kPa). This suggested that a higher level of water content favored an increase in activity of these two enzymes. In contrast,the urease activity decreased under irrigation, with less effect for MAD of -40 and -63 kPa. This implied that relatively wet soil conditions were conducive to retention of urea N, but relatively dry soil conditions could result in increasing loss of urea N. Further, this study revealed that soil enzyme activities could be alternative natural bio-sensors for the effect of irrigation on soil biochemical reactions and could help optimize irrigation management of greenhouse crop production.

  14. CROP DENSITY AND IRRIGATION WITH SALINE WATER

    OpenAIRE

    Feinerman, Eli

    1983-01-01

    The economic implications of plant density for irrigation water use under saline conditions are investigated, utilizing the involved physical and biological relationships. The analysis considers a single crop and is applied to cotton data. The results suggest that treating plant density as an endogenous control variable has substantial impact on profits and the optimal quantities and qualities of the applied irrigation water.

  15. Tomato Root Response to Subsurface Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Yu-Ping; ZHANG Xu-Dong; ZHANG Yu-Long; LI Jun; YANG Li-Juan; HUANG Yi; LIU Ming-Da

    2004-01-01

    Four depth treatments of subsurface drip irrigation pipes were designated as 1) at 20,2) 30 and 3) 40 cm depths all with a drip-proof flumes underneath,and 4) at 30 cm without a drip-proof flume to investigate the responses of a tomato root system to different technical parameters of subsurface drip irrigation in a glass greenhouse,to evaluate tomato growth as affected by subsurface drip irrigation,and to develop an integrated subsurface drip irrigation method for optimal tomato yield and water use in a glass greenhouse. Tomato seedlings were planted above the subsurface drip irrigation pipe. Most of the tomato roots in treatment 1 were found in the top 0-20 cm soil depth with weak root activity but with yield and water use efficiency (WUE) significantly less (P ---- 0.05) than treatment 2; root activity and tomato yield were significantly higher (P = 0.05) with treatment 3 compared to treatment 1; and with treatment 2 the tomato roots and shoots grew harmoniously with root activity,nutrient uptake,tomato yield and WUE significantly higher (P= 0.05) or as high as the other treatments. These findings suggested that subsurface drip irrigation with pipes at 30 cm depth with a drip-proof flume placed underneath was best for tomato production in greenhouses. In addition,the irrigation interval should be about 7-8 days and the irrigation rate should be set to 225 m3 ha-1 per event.

  16. Water Resources Impacts on Tribal Irrigation Projects

    Science.gov (United States)

    Minihane, M.

    2015-12-01

    The Bureau of Indian Affairs (BIA) Branch of Irrigation and Power provides oversight and technical support to select irrigation projects and systems on tribal lands. The BIA provides operations and maintenance support for 16 irrigation systems. To make the best use of limited resources, the BIA must incorporate climate change impacts on hydrology and water management for these irrigation systems in the coming decades. The 16 irrigation projects discussed here are divided into three climatological regions: the Pacific Northwest Region, the Greater Rocky Mountain Region, and the Western, Southwest, & Navajo Region. Significant climate projections that impact irrigation systems in one or more of these regions include increased temperatures and evaporative demand, earlier snowmelt and runoff, an increase in floods, an increase in heavy precipitation events, an increase in the frequency and intensity of droughts, and declining water supplies. Some irrigation projects are particularly vulnerable to these climate impacts because they are in already water-stressed areas or areas in which water resources are over-allocated. Other irrigation projects will have to adjust their storage and water management strategies to accommodate changes in the timing of streamflow. Overall, though, the BIA will be better able to assist tribal nations by incorporating expected climate impacts into their water resources management practices.

  17. Effect of low-cost irrigation methods on microbial contamination of lettuce irrigated with untreated wastewater

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, P.

    2007-01-01

    without caps from a height >1 m. CONCLUSION: Simple, cheap and easily adoptable irrigation methods have great potential to reduce crop contamination in low-income areas. When used in combination with other on-farm and post-harvest risk reduction measures, these will help to comprehensively reduce public......OBJECTIVE: To assess the effectiveness of simple irrigation methods such as drip irrigation kits, furrow irrigation and use of watering cans in reducing contamination of lettuce irrigated with polluted water in urban farming in Ghana. METHODS: Trials on drip kits, furrow irrigation and watering...... cans were conducted with urban vegetable farmers. Trials were arranged in a completely randomised block design with each plot having all three irrigation methods tested. This was conducted in both dry and wet seasons. Three hundred and ninety-six lettuce, 72 soil, 15 poultry manure and 32 water samples...

  18. Reclaimed Water for Turfgrass Irrigation

    Directory of Open Access Journals (Sweden)

    Xunzhong Zhang

    2010-09-01

    Full Text Available Sustainable irrigation of turfgrass grown on coarse-textured soils with reclaimed water must avoid detrimental effects of soluble salts on plant growth and soil quality and groundwater enrichment of nitrogen (N and phosphorus (P. The purpose of this study was (1 to investigate the effects of irrigating with municipal reclaimed water containing higher concentrations of soluble salts than potable water on turfgrass growth and quality and (2 to compare the effects of reclaimed and potable water on turfgrass assimilation and leaching of N and P. A sand-based medium plumbed to supply potable and reclaimed water and instrumented with lysimeters to collect leachate was planted with hybrid bermudagrass (Cynodon dactylon x Cynodon transvaalensis var. Tifsport and creeping bentgrass (Agrostis stolonifera var. L-93. Both species produced high quality turfgrass with the reclaimed water. Although both grasses are moderately or highly salt tolerant when fully established, the bermudagrass growth and quality were reduced by the reclaimed water upon breaking dormancy, and its N use during this period was reduced. Continuous use of reclaimed water of the quality used in the study poses a potential soil Na accumulation problem. Both turfgrasses assimilated high amounts of N and P with minimal potential losses to groundwater.

  19. [Irrigants and intracanal medicaments in endodontics].

    Science.gov (United States)

    Zehnder, Matthias; Lehnert, Birgit; Schönenberger, Kathrin; Waltimo, Tuomas

    2003-01-01

    Modern, biologic root canal therapy should be performed with suitable irrigating solutions and intracanal medicaments. The goal of endodontic treatment is to free the treated tooth from infection and prevent reinfection as thoroughly as possible by means which do not put the organism at risk. In this review of the literature, an evidence-based concept for irrigation and medication of root canal systems is presented. Irrigants and medicaments are discussed with respect to their antimicrobial, tissue-dissolving and endotoxin-decontaminating capacity in relation to their systemic toxicity. Recent findings pertaining to interactions of root canal medicaments and irrigating solutions and their impact on a sound irrigating and medicating concept are discussed.

  20. Impact of exogenous organic carbon on the removal of chemicals of concern in the high rate nitrifying trickling filters.

    Science.gov (United States)

    Mai, Lei; van den Akker, Ben; Du, Jun; Kookana, Rai S; Fallowfield, Howard

    2016-06-01

    The application of fixed bed high rate nitrifying trickling filters (NTFs) for the removal of track organic chemicals of concern (CoC) is less well known than their application to nutrient removal in water treatment. Particularly, the effect of exogenous organic carbon substrate (sucrose) loading on the performance of NTFs is not well understood. A laboratory-scale NTF system was operated in recirculation mode, with the objective of removing ammonia and CoC simultaneously. The efficiency of a high rate NTF for removal both of low concentration of ammonia (5 mg NH4-N L(-1)) and different concentrations of CoC in the presence of an exogenous organic carbon substrate (30 mg total organic carbon (TOC) L(-1)) was investigated. In the presence of exogenous organic carbon, the results demonstrated that the high rate NTF was able to successfully remove most of the CoCs investigated, with the removal ranging from 20.2% to 87.54%. High removal efficiencies were observed for acetaminophen (87.54%), bisphenol A (86.60%), trimethoprim (86.24%) and 17α-ethynylestradiol (80.60%). It was followed by the medium removal efficiency for N, N-diethyl-m-toluamide (61.31%) and atrazine (56.90%). In contrast, the removal of caffeine (28.43%) and benzotriazole (20.20%) was poorer in the presence of exogenous organic carbon. The removal efficiency for CoC was also compared with the results obtained in our previous study in the absence of exogenous organic carbon. The results showed that the addition of exogenous organic carbon was able to improve the removal of some of the CoC. Significant TOC percentage removals (45.68%-84.43%) and ammonia removal rate (mean value of 0.44 mg NH4-N L(-1) h(-1)) were also achieved in this study. The findings from this study provide valuable information for optimising the efficiency of high rate NTF for the removal of ammonia, CoC and TOC.

  1. Potential of organic filter materials for treating greywater to achieve irrigation quality: a review.

    Science.gov (United States)

    Dalahmeh, Sahar S; Hylander, Lars D; Vinnerås, Björn; Pell, Mikael; Oborn, Ingrid; Jönsson, Håkan

    2011-01-01

    The objectives of this literature review were to: (i) evaluate the impact of greywater generated in rural communities, with the emphasis on Jordanian conditions, on soil, plant and public health and assess the need for treatment of this greywater before it is used for irrigation, and (ii) assess the potential of different types of organic by-products as carrier material in different filter units for removal of pollutants from greywater. Greywater with high BOD5, COD, high concentrations of SS, fat, oil and grease and high levels of surfactants is commonly found in rural areas in Jordan. Oxygen depletion, odour emission, hydrophobic soil phenomena, plant toxicity, blockage of piping systems and microbiological health risks are common problems associated with greywater without previous treatment. Organic by-products such as wood chips, bark, peat, wheat straw and corncob may be used as carrier material in so-called mulch filters for treating wastewater and greywater from different sources. A down-flow-mode vertical filter is a common setup used in mulch filters. Wastewaters with a wide range of SS, cBOD5 and COD fed into different mulch filters have been studied. The different mulch materials achieved SS removal ranging between 51 and 91%, a BOD5 reduction range of 55-99.9%, and COD removal of 51-98%. Most types of mulches achieved a higher organic matter removal than that achieved by an ordinary septic tank. Bark, peat and wood chips filters removed organic matter better than sand and trickling filters, under similar conditions. Release of filter material and increase in COD in the effluent was reported using some mulch materials. In conclusion, some mulch materials such as bark, peat and woodchips seem to have a great potential for treatment of greywater in robust, low-tech systems. They can be expected to be resilient in dealing with variable low and high organic loads and shock loads.

  2. Historical influence of irrigation on climate extremes

    Science.gov (United States)

    Thiery, Wim; Davin, Edouard L.; Lawrence, Dave; Hauser, Mathias; Seneviratne, Sonia I.

    2016-04-01

    Land irrigation is an essential practice sustaining global food production and many regional economies. During the last decades, irrigation amounts have been growing rapidly. Emerging scientific evidence indicates that land irrigation substantially affects mean climate conditions in different regions of the world. However, a thorough understanding of the impact of irrigation on extreme climatic conditions, such as heat waves, droughts or intense precipitation, is currently still lacking. In this context, we aim to assess the historical influence of irrigation on the occurrence of climate extremes. To this end, two simulations are conducted over the period 1910-2010 with a state-of-the-art global climate model (the Community Earth System Model, CESM): a control simulation including all major anthropogenic and natural external forcings except for irrigation and a second experiment with transient irrigation enabled. The two simulations are evaluated for their ability to represent (i) hot, dry and wet extremes using the HadEX2 and ERA-Interim datasets as a reference, and (ii) latent heat fluxes using LandFlux-EVAL. Assuming a linear combination of climatic responses to different forcings, the difference between both experiments approximates the influence of irrigation. We will analyse the impact of irrigation on a number of climate indices reflecting the intensity and duration of heat waves. Thereby, particular attention is given to the role of soil moisture changes in modulating climate extremes. Furthermore, the contribution of individual biogeophysical processes to the total impact of irrigation on hot extremes is quantified by application of a surface energy balance decomposition technique to the 90th and 99th percentile surface temperature changes.

  3. Determination of Water Use Effectiveness in Hayrabolu Irrigation Scheme

    Directory of Open Access Journals (Sweden)

    A.N.Yuksel

    2005-05-01

    Full Text Available This study was conducted to determine the effectiveness of irrigation water use in HayraboluIrrigation Scheme, established in 1987 and transferred to irrigation cooperative. The study was completed intwo years in order to minimize the meteorological and environmental effects on evapotranspiration andirrigation water requirement. Irrigation application efficiency and sufficiency of farmer irrigation applicationwere investigated at 20 different farmers’ fields.Pressurized irrigation was prevailed (51 % and irrigation efficiency for sprinkler and surfaceirrigation methods were 61 and 62 %, respectively. Irrigation water losses on the scheme basis was 11,91 %.It was further determined that farmers irrigated their crops according to the phonological observation, did nottake the permissible consumption level of water content and applied insufficient water to satisfy the fieldcapacity. Among the predominantly grown crops, wheat and sunflower were not irrigated assuming that theprecipitation was sufficient to meet their demand while onion and corn were under-supplied. Generally, aneffective irrigation programme was not realised.

  4. Use of the rice husk as an alternative substrate for growing media on green walls drip irrigation

    Science.gov (United States)

    Andrey Rivas-Sánchez, Yair; Fátima Moreno-Pérez, María; Roldán Cañas, José

    2017-04-01

    In the last years, we have been looking for alternatives to traditional growing mediums for green walls. Commercially available systems for green walls are commonly made with Sphagnum, rock wool or polymers that are unsustainable materials. In the design of the green wall, local components such as agricultural by-products should be considered more often. The objective of this research is to use alternative materials available in Andalusia that are suitable for use as a growing medium in green walls, using organic residues generated by agriculture as in this case the rice husk, compared to conventional and used materials as a growing media in green walls such as coconut fiber and rock wool. The physical-chemical characteristics of the water were analyzed through the collection of excess irrigation water, after passing through the prototypes of green walls, installed in the Rabanales Campus of the University of Córdoba between April and July 2016 and thus observe the feasibility of using rice husk as an alternative material. The 16 mm diameter irrigation pipes are at the top and middle of each module, with 12 adjustable drippers of 4 l / h for each module, 72 drippers in the whole experimental green wall prototype installed at every 15 centimeters of tube. Two different species of plant material (Lampranthus spectabilis) and (Lavandula stoechas), were selected, taking into account the solar exposition of the place of establishment of the prototype of the green wall and the easy acquisition of these plants in the region. Water samples were collected every day twice a day for 10 weeks of the experiment, taking a sample of the surplus runoff water from six green wall prototypes.PH 40 - pH - conductivity - TDS - temperature, CRISON. Differences in pH, electrical conductivity, turbidity and total solids of the treatments were examined by ANOVA with the test of normality and homogeneity of variances. It was observed that the substrates used in the prototypes of the

  5. Mediterranean irrigation under climate change: more efficient irrigation needed to compensate for increases in irrigation water requirements

    Science.gov (United States)

    Fader, M.; Shi, S.; von Bloh, W.; Bondeau, A.; Cramer, W.

    2016-03-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 concentrations may affect irrigation requirements in the Mediterranean region by 2080-2090. Future demographic change and technological improvements in irrigation systems are taken into account, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL (Lund-Potsdam-Jena managed Land) after an extensive development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries such as Syria, Egypt and Turkey have a higher savings potential than others. Currently some crops, especially sugar cane and agricultural trees, consume on average more irrigation water per hectare than annual crops. Different crops show different magnitudes of changes in net irrigation requirements due to climate change, the increases being most pronounced in agricultural trees. The Mediterranean area as a whole may face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (4 and 18 % with 2 °C global warming combined with the full CO2-fertilization effect and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the southern and eastern Mediterranean. However, improved irrigation technologies and conveyance systems have a large water saving potential, especially in the eastern Mediterranean, and may be able to

  6. Debris and irrigant extrusion potential of 2 rotary systems and irrigation needles.

    Science.gov (United States)

    Altundasar, Emre; Nagas, Emre; Uyanik, Ozgur; Serper, Ahmet

    2011-10-01

    The purpose of this study was to compare the amount of apically extruded irrigant using 2 Ni-Ti rotary systems. Forty mandibular premolars with single canals were randomly assigned into 4 groups. Flower arrangement foam cubes were weighed with a precision balance before being attached to the apical portions of all teeth. In group 1, preparation was completed with ProTaper files. In group 2 canals were prepared with RaCe files. In groups 1 and 2, the irrigant was delivered with a 30-gauge conventional dental needle. In groups 3 and 4, teeth were prepared as in groups 1 and 2 with the exception that the irrigant was delivered with a side-vented irrigation needle. The weight of the extruded material (irrigant and debris) for each group was calculated by comparing the pre- and postinstrumentation weights of the foams used for periapical modeling. Obtained data were analyzed by Kruskal-Wallis and Mann-Whitney U tests, with P equals .05 as the level for statistical significance. ProTaper files used with regular needle irrigation had the highest fluid extrusion. The lowest irrigant extrusion was observed with the RaCe system combined with a side-vented irrigation needle. Within the limitations of this study, it can be concluded that irrigation needle and rotary instruments have an effect on the amount of extruded root canal irrigant.

  7. Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions.

    Science.gov (United States)

    Mozo, Sandra; Llena, Carmen; Forner, Leopoldo

    2012-05-01

    Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layers and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation.

  8. Biological degradation of chernozems under irrigation

    Directory of Open Access Journals (Sweden)

    Oksana Naydyonova

    2014-12-01

    Full Text Available We studied the changes in the state of microbial cenosis of Ukraine’s chernozems under irrigation. Considerable part of Ukraine’s chernozems is located in the areas where humidification is insufficient and unstable. Irrigation is a soil-reclamation measure for chernozems of Ukrainian Forest-steppe and Steppe which enables getting the assured yield, especially vegetable and fodder crops. At the same time, irrigation is a powerful anthropogenic factor that affects the soil, causes a significant transformation of many of its properties and regimes including biological ones. Often these changes are negative. The purpose of our investigation was to identify changes in the state of microbial cenoses of chernozem soils under irrigation which depend on such factors as the quality of irrigation water, the duration and intensity of irrigation, the initial properties of soil, the structure of crop rotation, usage of fertilizing systems and agroameliorative techniques. We identified direction and evaluated a degree of changes in biological properties of chernozems under influence of irrigation in different agro-irrigational and soil-climatic conditions. In the long-term stationary field experiments we identified the following biological indices of irrigated soils and their non-irrigated analogues: a number of microorganisms which belong to main ecological-trophic groups, activity of soil enzymes (dehydrogenase, invertase, phenol oxidase, soil phytotoxic activity, cellulose destroying capacity of soil, indices of oligotrophy and mineralization, summary biological index (SBI and index of biological degradation (BDI. Results of researches showed that irrigation unbalanced the soil ecosystem and stipulated the forming of microbial cenosis with new parameters. Long-term intensive irrigation of typical chernozem (Kharkiv Region with fresh water under condition of 4-fields vegetable crop rotation led to the degradation changes of its microbial cenosis such as

  9. Irrigation Water Management in Latin America

    Directory of Open Access Journals (Sweden)

    Aureo S de Oliveira

    2009-12-01

    Full Text Available Latin American countries show a great potential for expanding their irrigated areas. Irrigation is important for strengthening local and regional economy and for enhancing food security. The present paper aimed at providing a brief review on key aspects of irrigation management in Latin America. Poor irrigation management can have great impact on crop production and on environment while good management reduces the waste of soil and water and help farmers maximizing their profits. It was found that additional research is needed to allow a better understanding of crop water requirements under Latin American conditions as well as to provide farmers with local derived information for irrigation scheduling. The advantages of deficit irrigation practices and the present and future opportunities with the application of remote sensing tools for water management were also considered. It is clear that due to the importance of irrigated agriculture, collaborative work among Latin American researchers and institutions is of paramount importance to face the challenges imposed by a growing population, environment degradation, and competition in the global market.

  10. Irrigation of treated wastewater in Braunschweig, Germany

    DEFF Research Database (Denmark)

    Ternes, T.A.; Bonerz, M.; Herrmann, N.

    2007-01-01

    In this study the fate of pharmaceuticals and personal care products which are irrigated on arable land with treated municipal waste-water was investigated. In Braunschweig, Germany, wastewater has been irrigated continuously for more than 45 years. In the winter time only the effluent...... of digested sludge, because many polar compounds do not sorb to sludge and lipophilic compounds are not mobile in the soil-aquifer. Most of the selected PPCPs were never detected in any of the lysimeter or groundwater samples, although they were present in the treated wastewater irrigated onto the fields...

  11. Irrigation water use in Kansas, 2013

    Science.gov (United States)

    Lanning-Rush, Jennifer L.

    2016-03-22

    This report, prepared by the U.S. Geological Survey in cooperation with the Kansas Department of Agriculture, Division of Water Resources, presents derivative statistics of 2013 irrigation water use in Kansas. The published regional and county-level statistics from the previous 4 years (2009–12) are shown with the 2013 statistics and are used to calculate a 5-year average. An overall Kansas average and regional averages also are calculated and presented. Total reported irrigation water use in 2013 was 3.3 million acre-feet of water applied to 3.0 million irrigated acres.

  12. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation. Thre

  13. Reform in Indian canal irrigation: does technology matter?

    NARCIS (Netherlands)

    Narain, V.

    2008-01-01

    This paper examines the implications of technology - the design of canal irrigation for irrigation management reform. With reference to two different design systems in Indian irrigation - shejpali and warabandi - it shows that the potential for reform varies with the design of canal irrigation.

  14. Role of sediment in the design and management of irrigation canals : Sunsari Morang Irrigation Scheme, Nepal

    OpenAIRE

    Paudel, K.

    2010-01-01

    Sediment transport in irrigation canals The sediment transport aspect is a major factor in irrigation development as it determines to a large extent the sustainability of an irrigation scheme, particularly in case of unlined canals in alluvial soils. Investigations in this respect started since Kennedy published his channel-forming discharge theory in 1895. Subsequently different theories have been developed and are used around the world. All of them assume uniform and steady flow conditions ...

  15. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development. In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment. Field dye staining experiments were conducted at different soils with various irrigation amount. Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency. Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage efficiency, and uniformity. Under the same irrigation condition, soil chemical distributions were more heterogeneous than soil water distributions. The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount. Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount. Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uniformity, which resulted in high environmental risks of groundwater pollution.

  16. Analysis of Irrigation Water Quality at Kadawa Irrigation Project for Improved Productivity

    Directory of Open Access Journals (Sweden)

    AR Sanda

    2014-09-01

    Full Text Available In the face of water scarcity and the several negative consequences, such as water wastage, flooding, water logging, soil losses and production losses, conserving the finite amount of fresh water is a must. The quality of irrigation water must therefore be ascertained. The chemical quality of three sources of irrigation water from canal and drainage water, namely drainage water, fresh irrigation water from canal, and drainage/irrigation water mixture, were analyzed from Kadawa irrigation Project for year 2013 and 2014 cropping seasons, with the view to evaluating the potential risks associated with their use in irrigation and hence their suitability or otherwise for irrigation purposes. The analysis revealed that the use of drainage water alone for irrigation may result in problems associated with salinity, while a blend of drainage/irrigation water in the ratio of 1:1 is a viable means of water conservation and a good means of crop production. DOI: http://dx.doi.org/10.3126/ije.v3i3.11082 International Journal of Environment Vol.3(3 2014: 235-240

  17. Farmers’ Willingness to Pay for Irrigation Water: A Case of Tank Irrigation Systems in South India

    Directory of Open Access Journals (Sweden)

    Karthikeyan Chandrasekaran

    2009-08-01

    Full Text Available The economic value of tank irrigation water was determined through Contingency Valuation Method by analyzing farmers’ willingness to pay for irrigation water under improved water supply conditions during wet and dry seasons of paddy cultivation. Quadratic production function was also used to determine the value of irrigation water. The comparison of the economic value of water estimated using different methods strongly suggests that the present water use pattern will not lead to sustainable use of the resource in the tank command areas. Policy options for sustainable use of irrigation water and management of tanks in India were suggested.

  18. Catalytic wet air oxidation of bisphenol A solution in a batch-recycle trickle-bed reactor over titanate nanotube-based catalysts.

    Science.gov (United States)

    Kaplan, Renata; Erjavec, Boštjan; Senila, Marin; Pintar, Albin

    2014-10-01

    Catalytic wet air oxidation (CWAO) is classified as an advanced oxidation process, which proved to be highly efficient for the removal of emerging organic pollutant bisphenol A (BPA) from water. In this study, BPA was successfully removed in a batch-recycle trickle-bed reactor over bare titanate nanotube-based catalysts at very short space time of 0.6 min gCAT g(-1). The as-prepared titanate nanotubes, which underwent heat treatment at 600 °C, showed high activity for the removal of aqueous BPA. Liquid-phase recycling (5- or 10-fold recycle) enabled complete BPA conversion already at 200 °C, together with high conversion of total organic carbon (TOC), i.e., 73 and 98 %, respectively. The catalyst was chemically stable in the given range of operating conditions for 189 h on stream.

  19. Removal and transformation of organic matters in domestic wastewater during lab-scale chemically enhanced primary treatment and a trickling filter treatment

    Institute of Scientific and Technical Information of China (English)

    Qingliang Zhao; Huiyuan Zhong; Kun Wang; Liangliang Wei; Jinli Liu; Yu Liu

    2013-01-01

    To find a simple and economical way for treating the domestic wastewater in small counties and towns,a process combining chemically enhanced primary treatment and a trickling filter (CEPT-TF,representing the physical and biological effects) was constructed and operated in laboratory conditions.The characteristic behaviors of dissolved organic matter in raw wastewater and effluents were examined during steady-state operation.Experimental results showed that the process of CEPT and TF in series was beneficial for the removal of hydrophobic and hydrophilic organics.Specially,the hydrophobic and aromatic materials could be preferentially removed in the CEPT unit,and the hydrophilic fraction in the TF.Structural changes of the organic fractions during the operation of the different units were also characterized via spectrum analysis.

  20. Strategic irrigation against apple scab (Venturia inaequalis)

    DEFF Research Database (Denmark)

    Korsgaard, Maren

    2012-01-01

    In Denmark there are several organic orchards, that do not spray at all, and they seek non-spraying methods to prevent apple scab. In this pilot trial, irrigation with water at strategic moments was tested to prevent scab-infection. In April-June 2011 in five organic orchards we irrigated...... the orchard floor, to force the ascospores to be released. We irrigated with at least 0.2 mm of water in dry periods, at least 12 hours before rain forecast. The idea was to empty the stock of ascospores during dry spells, so they would dry out without infecting the leaves. To find the best strategic times...... for irrigation, we used the local weather forecast and the scab-warning programme Rimpro based on data from climate stations located in the orchards. In this first year of trial we experienced difficulties in spreading the water evenly. A water wagon turned out to work better than sprinklers. We found...

  1. Estimated Irrigated Agricultural Water Use In 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset is a 100-meter cell resolution raster dataset of estimated use of irrigated agricultural water use data for the southwestern U.S. The dataset was...

  2. Interpreting hydrodynamic behaviour by the model of stirred tanks in series with exchanged zones: preliminary study in lab-scale trickling filters.

    Science.gov (United States)

    Zeng, Ming; Soric, Audrey; Ferrasse, Jean-Henry; Roche, Nicolas

    2013-01-01

    In trickling filters for wastewater treatment, hydrodynamic behaviour is affected by the growth of biofilm on the porous medium. Therefore, modelling hydrodynamic behaviour is necessary and efficient to predict the biodegradation of pollutants. In this study, laboratory-scale trickling filters were filled with two different porous media (glass beads and plastic rings) and were fed by a synthetic substrate in batch mode. Total organic carbon (TOC) of the effluent was measured and retention time distribution (RTD) was determined by injecting NaCl. Results showed that medium had no significant effect on TOC removal rate (around 80% and 60% respectively for batch time of seven and two days). However, regarding the hydrodynamic behaviour, the effective volume ratio and hydraulic efficiency in the glass beads bed increased remarkably from 28% and 18% to 80% and 70%, respectively, with the reduction of dispersion coefficient (from 4.55 to 1.53). Moreover, the short batch time accelerated this change. Conversely, no variation of hydrodynamic behaviour in plastic rings bed was evident. Along with the feeding of synthetic substrate, biofilm concentration ranged from 1.5 to 10.1 g/L in the glass beads reactor and it achieved around 2.8 g/L in the plastic rings reactor. Hydrodynamic modelling indicated that the model of stirred tanks in series with exchanged zones fitted the experimental results well. These gave values of mobile and immobile volumes of 51 mL and 17 mL, respectively, in the glass beads filter and 25 mL and 15 mL, respectively, in the plastic rings filter.

  3. Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Ovejero, Gabriel, E-mail: govejero@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Rodríguez, Araceli [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Peres, José A. [Centro de Química de Vila Real, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real (Portugal); García, Juan, E-mail: juangcia@quim.ucm.es [Grupo de Catálisis y Procesos de Separación (CyPS), Departamento de Ingeniería Química, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2013-01-15

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Chromotrope 2R removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to bare-usable after in situ regeneration. -- Abstract: Active nickel catalysts (7 wt%) supported over Mg–Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min{sup −1} and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min{sup −1}, respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T{sub r} = 0.098 g{sub Ni} min mL{sup −1}. After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T{sub r} = 0.098 g{sub Ni} min mL{sup −1}, attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity.

  4. Development of a protective immunity against Ostertagia leptospicularis in trickle-infected sheep and parallel changes of serum gastrin, pepsinogen and antibody levels.

    Science.gov (United States)

    Hertzberg, H; Schallig, H D; Deplazes, P

    1999-03-01

    Nine lambs, approximately 9 months of age were allocated to three groups (A, B, C), with three animals in each. Sheep in Groups A and B were trickle-infected with doses of 1000 third-stage larvae (L3) of Ostertagia leptospicularis (five times per week) over periods of 7.5 and 10.5 weeks, respectively, and were subsequently treated with fenbendazole (7.5 mg/kg). Approximately 3 weeks after anthelmintic treatment, all sheep were challenged with a single dose of 100,000 L3, whereas sheep of Group C received the same dose as a primary infection. Sheep of Groups A and B were almost completely refractory against the challenge infection, as indicated by negative faecal egg counts and adult worm burdens. A relatively high infection level was present in the sheep of Group C. The results indicate that a comparatively short immunization period of 7.5 weeks is sufficient to protect lambs against subsequent larval challenge. During immunization, the pepsinogen-, gastrin- and IgA-responses were similar in the individual sheep. In contrast to parasite-specific IgG1 and IgG2 levels, IgA decreased rapidly after cessation of trickle infection and parallel anthelmintic treatment, and may therefore indicate current exposure to parasite antigen. After challenge, the majority of the immunized sheep exhibited immediate and short-term responses of pepsinogen, gastrin and IgA in the serum. The time course and the level of each of these responses were very similar in the individual sheep, suggesting that the release of pepsinogen, gastrin and IgA into the circulation was influenced by related mechanisms.

  5. Proceedings of the solar irrigation workshop

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-06-01

    The ERDA Solar Irrigation Workshop was structured to be a major vehicle for information dissemination and technology transfer. It covered a wide range of subject matter related to crop irrigation including current hardware, economics, experiments, and international requirements. Speakers represented manufacturers, ranchers, governmental entities, universities and research firms. The proceedings consist of one page abstracts for each presentation, a brief biographical sketch of each speaker and sources for further information on each subject.

  6. Smart Water Conservation System for Irrigated Landscape

    Science.gov (United States)

    2016-05-01

    by the Energy Independence and Security Act (EISA). Reducing potable water demand for landscape irrigation correlates to lower energy costs necessary...irrigation is necessary. Typically, timer-based systems are adjusted higher than needed to account for consecutive hot days that stress turf beyond the...implementation at sports field, parade grounds, and/or landscape near buildings. Appendix C details the life cycle cost for the smart water

  7. Irrigation enhances precipitation at the mountains downwind

    Directory of Open Access Journals (Sweden)

    J. Jódar

    2010-05-01

    Full Text Available Atmospheric circulation models predict an irrigation-rainfall feedback. However, actual field evidences are very weak. We present strong field evidence about an increase in rainfall at the mountains located downwind of irrigated zones. We chose two regions, located in semiarid southern Spain, where irrigation started at a well defined date, and we analyzed rainfall statistics before and after the beginning of irrigation. Analyzed statistics include the variation of (1 mean rainfall Δ P, (2 ratio of monthly precipitation to annual precipitation Δ r, and (3 number of months with minimum rainfall episodes Δ Pmin after a transition period from unirrigated to irrigated conditions. All of them show statistically significant increases. Δ P and Δ r show larger and more statistically significant variations in June and July. Their variation is proportional to the mean annual water volume applied in the neighboring upwind irrigation lands. Variations in Δ Pmin are statistically significant in the whole summer. That is, the number of months with some rain displays a relevant increase after irrigation. However, increase in rainfall while statistically significant is distributed over a broad region, so that it is of little relevance from a water resources perspective. The joint increment in Δ P and Δ Pmin after the irrigation transition period denotes a net increase in the number of months having a minimum cumulated precipitation in summer.

  8. Irrigation et paludisme : un couple infernal?

    OpenAIRE

    Mergeai, G.

    2016-01-01

    Irrigation and Malaria - a Terrible Combination?. Increasing agricultural productivity is a priority in most of the developing countries and using irrigation is one of the most efficient ways of achieving this goal. Almost half a billion people in the world contract malaria every year and approximately one million die as a result. The majority of these victims are farmers or members of their families. In infected areas, malaria continues to have major negative impacts on agricultural producti...

  9. Grower demand for sensor-controlled irrigation

    Science.gov (United States)

    Lichtenberg, Erik; Majsztrik, John; Saavoss, Monica

    2015-01-01

    Water scarcity is likely to increase in the coming years, making improvements in irrigation efficiency increasingly important. An emerging technology that promises to increase irrigation efficiency substantially is a wireless irrigation sensor network that uploads sensor data into irrigation management software, creating an integrated system that allows real-time monitoring and control of moisture status that has been shown in experimental settings to reduce irrigation costs, lower plant loss rates, shorten production times, decrease pesticide application, and increase yield, quality, and profit. We use an original survey to investigate likely initial acceptance, ceiling adoption rates, and profitability of this new sensor network technology in the nursery and greenhouse industry. We find that adoption rates for a base system and demand for expansion components are decreasing in price, as expected. The price elasticity of the probability of adoption suggests that sensor networks are likely to diffuse at a rate somewhat greater than that of drip irrigation. Adoption rates for a base system and demand for expansion components are increasing in specialization in ornamental production: growers earning greater shares of revenue from greenhouse and nursery operations are willing to pay more for a base system and are willing to purchase larger numbers of expansion components at any given price. We estimate that growers who are willing to purchase a sensor network expect investment in this technology to generate significant profit, consistent with findings from experimental studies.

  10. Mediterranean agriculture: More efficient irrigation needed to compensate increases in future irrigation water requirements

    Science.gov (United States)

    Fader, Marianela; Shi, Sinan; von Bloh, Werner; Bondeau, Alberte; Cramer, Wolfgang

    2016-04-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. Our research shows that, at present, Mediterranean region could save 35% of water by implementing more efficient irrigation and conveyance systems. Some countries like Syria, Egypt and Turkey have higher saving potentials than others. Currently some crops, especially sugar cane and agricultural trees, consume in average more irrigation water per hectare than annual crops (1). Also under climate change, more efficient irrigation is of vital importance for counteracting increases in irrigation water requirements. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4% and 18% from climate change alone by the end of the century if irrigation systems and conveyance are not improved. Population growth increases these numbers to 22% and 74%, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean, and may be able to compensate to some degree the increases due to climate change and population growth. Both subregions would need around 35% more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect (1). However, in some scenarios (in this case as combinations of climate change, irrigation technology, influence of population growth and CO2-fertilization effect) water scarcity may constrain the supply of the irrigation water needed in future in Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain (1). In this study, vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL ("Lund-Potsdam-Jena managed Land") after a

  11. A Real-time Irrigation Forecasting System in Jiefangzha Irrigation District, China

    Science.gov (United States)

    Cong, Z.

    2015-12-01

    In order to improve the irrigation efficiency, we need to know when and how much to irrigate in real time. If we know the soil moisture content at this time, we can forecast the soil moisture content in the next days based on the rainfall forecasting and the crop evapotranspiration forecasting. Then the irrigation should be considered when the forecasting soil moisture content reaches to a threshold. Jiefangzha Irrigation District, a part of Hetao Irrigation District, is located in Inner Mongolia, China. The irrigated area of this irrigation district is about 140,000 ha mainly planting wheat, maize and sunflower. The annual precipitation is below 200mm, so the irrigation is necessary and the irrigation water comes from the Yellow river. We set up 10 sites with 4 TDR sensors at each site (20cm, 40cm, 60cm and 80cm depth) to monitor the soil moisture content. The weather forecasting data are downloaded from the website of European Centre for Medium-Range Weather Forecasts (ECMWF). The reference evapotranspiration is estimated based on FAO-Blaney-Criddle equation with only the air temperature from ECMWF. Then the crop water requirement is forecasted by the crop coefficient multiplying the reference evapotranspiration. Finally, the soil moisture content is forecasted based on soil water balance with the initial condition is set as the monitoring soil moisture content. When the soil moisture content reaches to a threshold, the irrigation warning will be announced. The irrigation mount can be estimated through three ways: (1) making the soil moisture content be equal to the field capacity; (2) making the soil moisture saturated; or (3) according to the irrigation quota. The forecasting period is 10 days. The system is developed according to B2C model with Java language. All the databases and the data analysis are carried out in the server. The customers can log in the website with their own username and password then get the information about the irrigation forecasting

  12. Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

    NARCIS (Netherlands)

    Kooij, van der S.

    2016-01-01

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems

  13. Reducing microbial contamination on wastewater-irrigated lettuce by cessation of irrigation before harvesting

    DEFF Research Database (Denmark)

    Keraita, Bernard; Konradsen, Flemming; Drechsel, Pay;

    2007-01-01

    OBJECTIVE: To assess the effectiveness of cessation of irrigation before harvesting in reducing microbial contamination of lettuce irrigated with wastewater in urban vegetable farming in Ghana. METHODS: Assessment was done under actual field conditions with urban vegetable farmers in Ghana. Trials...

  14. Economic feasibility of converting center pivot irrigation to subsurface drip irrigation

    Science.gov (United States)

    Advancements in irrigation technology have increased water use efficiency. However, producers can be reluctant to convert to a more efficient irrigation system when the initial investment costs are high. This study examines the economic feasibility of replacing low energy precision application (LEPA...

  15. Performing drip irrigation by the farmer managed Seguia Khrichfa irrigation system, Morocco

    NARCIS (Netherlands)

    Kooij, van der S.

    2016-01-01

    Drip irrigation is represented in literature and agricultural policies as a modern and water saving technology. Because this technology is often associated with ‘modern’ agriculture and development, it seems out-of-place in ‘traditional’ farmer managed irrigation systems (FMI

  16. Irrigation Requirement Estimation Using Vegetation Indices and Inverse Biophysical Modeling

    Science.gov (United States)

    Bounoua, Lahouari; Imhoff, Marc L.; Franks, Shannon

    2010-01-01

    We explore an inverse biophysical modeling process forced by satellite and climatological data to quantify irrigation requirements in semi-arid agricultural areas. We constrain the carbon and water cycles modeled under both equilibrium, balance between vegetation and climate, and non-equilibrium, water added through irrigation. We postulate that the degree to which irrigated dry lands vary from equilibrium climate conditions is related to the amount of irrigation. The amount of water required over and above precipitation is considered as an irrigation requirement. For July, results show that spray irrigation resulted in an additional amount of water of 1.3 mm per occurrence with a frequency of 24.6 hours. In contrast, the drip irrigation required only 0.6 mm every 45.6 hours or 46% of that simulated by the spray irrigation. The modeled estimates account for 87% of the total reported irrigation water use, when soil salinity is not important and 66% in saline lands.

  17. Irrigation Analysis Based on Long-Term Weather Data

    Directory of Open Access Journals (Sweden)

    James R. Mahan

    2016-08-01

    Full Text Available Irrigation management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET using weather data. In 1994, an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. Though producers used the ET-network, by 2010 public access was discontinued. Why did producers allow a valuable irrigation-management tool to be eliminated? Our objective was to analyze the effect of declining well capacities on the usefulness of cotton ET (ETc for irrigation. Thirty years (1975–2004 of daily ETc data were used to compare irrigation demand vs. irrigation responses at four locations, analyzed for multiple years and range of well capacities for three irrigation-intervals. Results indicated that when well capacities declined to the point that over-irrigation was not possible, the lower well capacities reduced the value of ETc in terms of the number of irrigations and total amount of water applied. At well capacities <1514 L·min−1 the fraction of irrigations for which ETc information was used to determine the irrigation amount was <35% across years and irrigation intervals. The value of an ETc-based irrigation may fall into disuse when irrigation-water supplies decline.

  18. Effect of Different Alternate Irrigation Strategies using Saline and Non-Saline Water on Corn Yield, Salinity and Moisture Distribution in Soil Profile

    Directory of Open Access Journals (Sweden)

    Ali Reza Kiani

    2017-01-01

    Full Text Available Introduction: Lack of water and deterioration in the quality of soil and water resources are considered to be the prime cause of reduced crop yield in arid and semi-arid regions ‘More crop per drop’ by trickle irrigation, deficit irrigation, and uncommon water are the best strategies for mitigating water crises. Different irrigation management strategies are needed to increase production in different areas. In areas where sufficient water is available, a full irrigation strategy could be a suitable option, while in areas where water is limited, deficit irrigation would be an appropriate method, and finally in areas where water resources are saline, management strategies for achieving sustainable production as well as economic yields would be suitable. Maize is the third most important grain crop in the world following wheat and rice and it is the main source of nutrition for humans and animals. Because of the importance of maize in the world, increasing maize production under environmental stresses is a big challenge for agricultural scientists. Different methods of irrigation and the use of saline water that had satisfactory results for increasing agricultural production have been studied by several investigators . The main objective of this study was to establish an efficient use of limited water resources as well as to explore the possibility of replacing saline water with fresh water using different management techniques. Materials and Methods: A field experiment was conducted over two maize cropping seasons (2012–2013 in northern Iran (Gorgan Agricultural Research Station to compare different alternate irrigation scenarios using saline water on corn yield, salinity and soil moisture distribution in a randomized complete block design with three replications. Treatments were: T1 and T2 = 100 and 50 % of crop water requirement with non-saline water, respectively; T3 and T4 = variable and fixed full irrigation with saline and non

  19. Irrigation Training Manual. Planning, Design, Operation, and Management of Small-Scale Irrigation Systems [and] Irrigation Reference Manual. A Technical Reference to Be Used with the Peace Corps Irrigation Training Manual T0076 in the Selection, Planning, Design, Operation, and Management of Small-Scale Irrigation Systems.

    Science.gov (United States)

    Salazar, LeRoy; And Others

    This resource for trainers involved in irrigated agriculture training for Peace Corps volunteers consists of two parts: irrigation training manual and irrigation reference manual. The complete course should fully prepare volunteers serving as irrigation, specialists to plan, implement, evaluate and manage small-scale irrigation projects in arid,…

  20. ASPECTS OF DRIP IRRIGATION ON SLOPES

    Directory of Open Access Journals (Sweden)

    Oprea Radu

    2010-01-01

    Full Text Available Nowadays, water and its supply raise problems of strategic importance, of great complexity, being considered one of the keys to sustainable human development. Drip irrigation consists in the slow and controlled administration of water in the area of the root system of the plants for the purposes of fulfilling their physiological needs and is considered to be one of the variants of localized irrigation. Water is distributed in a uniform and slow manner, drop by drop, in a quantity and with a frequency that depend on the needs of the plant, thanks to the exact regulation of the water flow rate and pressure, as well as to the activation of the irrigation based on the information recorded by the tensiometer with regard to soil humidity. This method enables the exact dosage of the water quantity necessary in the various evolution stages of the plant, thus eliminating losses. By applying the irrigation with 5 liters of water per linear meter, at a 7 days interval, in the month of august, for a vine cultivated on a slope, in layers covered with black film and irrigated via dropping, soil humidity immediately after irrigation reaches its highest level, but within the limits of active humidity, on the line of the irrigation band. Three days later, the water content of the soil in the layer is relatively uniform, and, after this interval, it is higher in the points situated at the basis of the film. This technology of cultivation on slopes favors the accumulation, in the soil, of the water resulted from heavy rains and reduces soil losses as a result of erosion.

  1. Effects of irrigation fluid in shoulder arthroscopy

    Science.gov (United States)

    Gupta, Surbhi; Manjuladevi, M; Vasudeva Upadhyaya, KS; Kutappa, AM; Amaravathi, Rajkumar; Arpana, J

    2016-01-01

    Background and Aims: Extravasation of irrigation fluid used in shoulder arthroscopy can lead to life-threatening airway and systemic complications. This study was conducted to assess the effect of irrigation fluid absorption on measurable anthropometric parameters and to identify whether these parameters predict airway/respiratory compromise. Methods: Thirty six American Society of Anaesthesiologists physical status one or two patients aged 15–60 years undergoing shoulder arthroscopy under general anaesthesia were recruited. Measured variables preoperatively (baseline) and at the end of surgery were neck, chest, midarm and midthigh circumferences, weight, haemoglobin and serum sodium. Temperature, endotracheal tube cuff pressure, airway pressure, duration of surgery, amount of irrigation fluid and intravenous fluid used were also noted. Measured parameters were correlated with the duration of surgery and the amount of irrigation fluid used. Results: Postoperatively, the changes in variables showed a significant increase in the mean values (cm) for neck, chest, midarm and midthigh circumference (mean ± standard deviation: 2.35 ± 1.9, P cm, P compared to the baseline. No significant change was found in the serum sodium levels (P = 0.92). No patient experienced airway/respiratory compromise. Conclusion: Regional and systemic absorption of irrigation fluid in arthroscopic shoulder surgery is reflected in the degree of change in the measured anthropometric variables. However, this change was not significant enough to cause airway/respiratory compromise. PMID:27053783

  2. Municipal Treated Wastewater Irrigation: Microbiological Risk Evaluation

    Directory of Open Access Journals (Sweden)

    Antonio Lonigro

    2008-06-01

    Full Text Available Municipal wastewater for irrigation, though treated, can contain substances and pathogens toxic for humans and animals. Pathogens, although not harmful from an agronomical aspect, undoubtedly represent a major concern with regards to sanitary and hygienic profile. In fact, vegetable crops irrigated with treated wastewater exalt the risk of infection since these products can also be eaten raw, as well as transformed or cooked. Practically, the evaluation of the microbiological risk is important to verify if the microbial limits imposed by law for treated municipal wastewater for irrigation, are valid, thus justifying the treatments costs, or if they are too low and, therefore, they don’ t justify them. Different probabilistic models have been studied to assess the microbiological risk; among these, the Beta-Poisson model resulted the most reliable. Thus, the Dipartimento di Scienze delle Produzioni Vegetali of the University of Bari, which has been carrying out researches on irrigation with municipal filtered wastewater for several years, considered interesting to verify if the microbial limits imposed by the italian law n.185/03 are too severe, estimating the biological risk by the probabilistic Beta-Poisson model. Results of field trials on vegetable crops irrigated by municipal filtered wastewater, processed by the Beta-Poisson model, show that the probability to get infection and/or illness is extremely low, and that the actual italian microbial limits are excessively restrictive.

  3. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  4. Evaluation of mulched drip irrigation for cotton in arid Northwest China

    NARCIS (Netherlands)

    Wang, Z.; Jin, M.; Simunek, J.; van Genuchten, M.T.

    2014-01-01

    Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control

  5. The impact of irrigation on the quality of drainage water in a new irrigation district

    Directory of Open Access Journals (Sweden)

    J.M. Villar Mir

    2015-10-01

    Full Text Available The water quality of two agricultural drainage systems was monitored over two irrigation seasons in order to determine the sustainability of a new area of irrigated land (the Algerri-Balager irrigation district located in the northeast of Spain. The average electrical conductivity of the drainage water was around 4 dS·m-1, and the waters were enriched with boron, phosphorous and nitrate. Drainage represented 17% of total applied irrigation water (measured leached fraction and is considered necessary to minimize the risk of soil salinization in semiarid environments. The most common ions in the drainage waters were magnesium, sulphate, and calcium and others related with dissolved soil minerals present in the area. The presence of Fe, Cu, Mn, Zn and pesticides was negligible. The information provided by this research was very useful for the irrigation district, and it’s transferable to other irrigation districts, as it could help to improve agricultural practices and be used to control the quality and quantity of irrigation drainage.

  6. Dwarf cashew growth irrigated with saline waters

    Directory of Open Access Journals (Sweden)

    Hugo Orlando Carvallo Guerra

    2009-12-01

    Full Text Available The cashew production is one of the most important agricultural activities from the social-economical viewpoint for the North East of Brazil; besides to produce a great deal of hand labor, it is very important as an exporting commodity. The inadequate use of irrigation in the semi arid regions of the North East of Brazil has induced soil salinization and consequently problems for the irrigated agriculture. In spite of this, few works have been conducted to study the effect of saline stress on the growth and development of the cashew. Because of the lack of information for this crop, an experiment was conducted to study the effect of salinity stress on the phytomass production and nutrient accumulation on the different organs of the precocious dwarf cashew (Anacardium occidentale L. clone CCP76. The study was conducted under controlled conditions using as statistical scheme a randomized block design factorial with six replicates. Five salinity treatments were considered for the irrigation water (electrical conductivities of 0.8, 1.6, 2.4, 3.2 and 4.0 dS m-1 at 25oC. The increasing in salinity of the irrigation water reduced the phytomass at different organs of the studied plant. The nitrogen, phosphorus, potassium, chloride and sodium in the plant varied with the salinity of the irrigation water according with the part of the plant analyzed; in some parts increased, in others decreased, in others increased initially and decreased afterwards, and finally, in other part of the plant the salinity of the irrigation water did not affect the nutrient concentration.

  7. Irrigation methods for efficient water application: 40 years of South ...

    African Journals Online (AJOL)

    Irrigation methods for efficient water application: 40 years of South African ... to a specific situation rather than by calculating various performance indicators. ... of Irrigation Water Use covers 4 levels of water-management infrastructure: the ...

  8. Effects of ten years treated wastewater drip irrigation on soil ...

    African Journals Online (AJOL)

    Effects of ten years treated wastewater drip irrigation on soil microbiological properties under ... Water shortage in most countries of the southern Mediterranean basin has led to the reuse of municipal wastewater for irrigation. ... Article Metrics.

  9. Impact of Methods of Administering Growth-Stage Deficit Irrigation ...

    African Journals Online (AJOL)

    Impact of Methods of Administering Growth-Stage Deficit Irrigation on Yield and Soil Water ... study reveal that at vegetative growth stage of the maize crop, it is better to skip weekly irrigation (to ..... Treatment Class. ..... middle Egypt conditions.

  10. Effects of irrigation strategies and soils on field grown potatoes

    DEFF Research Database (Denmark)

    Ahmadi, Seyed Hamid; Plauborg, Finn; Andersen, Mathias Neumann

    2011-01-01

    Root distribution of field grown potatoes (cv. Folva) was studied in 4.32m2 lysimeters and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. Drip irrigation was applied for all irrigations. Irrigations were run in three different soils: coarse sand......, loamy sand, and sandy loam. Irrigation treatments started after tuber bulking and lasted until final harvest with PRD and DI receiving 65% of FI. Potatoes irrigated with water-saving irrigation techniques (PRD and DI) did not show statistically different dry root mass and root length density (RLD, cm...... root per cm3 soil) compared with root development in fully irrigated (FI) potatoes. Highest RLD existed in the top 30–40cm of the ridge below which it decreased sharply. The RLD was distributed homogenously along the ridge and furrow but heterogeneously across the ridge and furrow with highest root...

  11. Wireless sensor networks for canopy temperature sensing and irrigation management

    Science.gov (United States)

    For researchers, canopy temperature measurements have proven useful in characterizing crop water stress and developing protocols for irrigation management. Today, there is heightened interest in using remote canopy temperature measurements for real-time irrigation scheduling. However, without the us...

  12. Strategy of Irrigation Branch in Russia

    Science.gov (United States)

    Zeyliger, A.; Ermolaeva, O.

    2012-04-01

    At this moment, at the starting time of the program on restoration of a large irrigation in Russia till 2020, the scientific and technical community of irrigation branch does not have clear vision on how to promote a development of irrigated agriculture and without repeating of mistakes having a place in the past. In many respects absence of a vision is connected to serious backlog of a scientific and technical and informational and technological level of development of domestic irrigation branch from advanced one. Namely such level of development is necessary for the resolving of new problems in new conditions of managing, and also for adequate answers to new challenges from climate and degradation of ground & water resources, as well as a rigorous requirement from an environment. In such important situation for irrigation branch when it is necessary quickly generate a scientific and technical politics for the current decade for maintenance of translation of irrigated agriculture in the Russian Federation on a new highly effective level of development, in our opinion, it is required to carry out open discussion of needs and requirements as well as a research for a adequate solutions. From political point of view a framework organized in FP6 DESIRE 037046 project is an example of good practice that can serve as methodical approach how to organize and develop such processes. From technical point of view a technology of operational management of irrigation at large scale presents a prospective alternative to the current type of management based on planning. From point of view ICT operational management demands creation of a new platform for the professional environment of activity. This platform should allow to perceive processes in real time, at their partial predictability on signals of a straight line and a feedback, within the framework of variability of decision making scenarious, at high resolution and the big ex-awning of sensor controls and the gauges

  13. Genotoxicity of vegetables irrigated by industrial wastewater

    Institute of Scientific and Technical Information of China (English)

    Nupur Mathur; Pradeep Bhatnagar; Hemraj Verma

    2006-01-01

    Wastewater effluents from textile dyeing and printing industries of Sanganer are discharged directly, without any treatment,into Amani Shah Nallah drainage. The drainage water takes the dissolved toxicants to flora and fauna, including crops and seasonal vegetables, being grown in the land adjoining the Nallah drainage. Thus mutagenic potential of vegetables irrigated by the water of Amani Shah Nallah drainage was investigated in the present study. The vegetables irrigated by ground water from Sanganer have also been analyzed to determine possible adverse effects of these wastewater effluents on aqua duct.

  14. An Assessment of Global Net Irrigation Water Requirements from Various Water Supply Sources to Sustain Irrigation

    Science.gov (United States)

    Yoshikawa, Sayaka; Cho, Jail; Yamada, Hannah; Khajuria, Anupam; Hanasaki, Naota; Kanae, Shinjiro

    2014-05-01

    Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependence of irrigation water requirements from water supply sources, with a particular focus on variations in irrigation area during the period 1960-2050 using the global water resources model, H08. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0° . The sources of irrigation water requirements in the past simulations were specified using four categories: rivers (RIV), large reservoirs (LR) with a storage capacity greater than 1.0 km3, medium-size reservoirs (MSR) with storage capacities ranging from 1.0 km3 to 3.0 M m3, and non-local non-renewable blue water (NNBW). We also estimated future irrigation water requirements from the above four water supply sources and an additional water supply source (ADD) in three future simulation designs; irrigation area change, climate change, and changes in both irrigation area and climate. ADD was defined as the difference between NNBW in the 1990s and NNBW in the 2040s, because it was difficult to distinguish the types of future water supply sources except for RIV. The simulated results showed that RIV, MSR, and NNBW increased significantly through the 1960s to the early 1990s globally, but LR increased at a relatively low rate. After the early 1990s, RIV approached a critical limit due to the continued expansion of the irrigation area. Furthermore, MSR and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of the medium-size reservoirs. After the 2020s, MSR could be expected to approach the critical limit without the construction of medium-size reservoirs. ADD would account for 11-23% of the total requirements in the 2040s. We found that an expansion of

  15. Mapping Irrigation Potential in the Upper East Region of Ghana

    Science.gov (United States)

    Akomeah, E.; Odai, S. N.; Annor, F. O.; Adjei, K. A.; Barry, B.

    2009-04-01

    The Upper East Region together with the other two regions in Northern Ghana (Upper West and Northern Region) is seen as the locus of perennial food deficit (GPRS, 2003). Despite, the provision of over 200 small scale dams and various mechanisms aimed at poverty alleviation, the region is still plagued with poverty and yearly food shortages. To achieve food security and alleviate poverty in the region however, modernization of agriculture through irrigation is deemed inevitable. While it is true that considerable potential still exists for future expansion of irrigation, it cannot be refuted that water is becoming scarcer in the regions where the need for irrigation is most important, hence mapping the irrigation potential of the region will be the first step toward ensuring sound planning and sustainability of the irrigation developments. In this study, an attempt has been made to map out the irrigation potential of the Upper East Region. The river basin approach was used in assessing the irrigation potential. The catchments drained by The White Volta river, Red volta river, River Sissili and River Kulpawn were considered in the assessment. The irrigation potential for the sub basins was computed by combining information on gross irrigation water requirements for the selected cash crops, area of soil suitable for irrigation and available water resources. The capacity of 80%, 70%, 60% and 50% time of exceedance flow of the available surface water resources in the respective sub basins was estimated. The area that can be irrigated with this flow was computed with selected cropping pattern. Combining the results of the potential irrigable areas and the land use map of the respective sub basins, an irrigation potential map has been generated showing potential sites in the upper east region that can be brought under irrigation. Keywords: Irrigation potential, irrigation water requirement, land evaluation, dependable flow

  16. The management perspective on the performance of the irrigation subsector

    OpenAIRE

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the performance of irrigation investments was far below its potential. The size of this underperformance is well represented by Seckler's alarming conclusion that the average irrigation investment costs twi...

  17. A management perspective on the performance of the irrigation subsector.

    OpenAIRE

    Nijman, Ch.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the performance of irrigation investments was far below its potential. The size of this underperformance is well represented by Seckler's alarming conclusion that the average irrigation investment costs twi...

  18. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NARCIS (Netherlands)

    Chukalla, A.D.; Krol, M.S; Hoekstra, A.Y.

    2015-01-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thu

  19. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NARCIS (Netherlands)

    Chukalla, Abebe Demissie; Krol, Martinus S.; Hoekstra, Arjen Ysbert

    2015-01-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and

  20. Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

    Science.gov (United States)

    Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

    2014-08-01

    Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity.

  1. Nitrogen Effects on Onion Yield Under Drip and Furrow Irrigation

    Science.gov (United States)

    Onion (Allium cepa L.) is a high cash value crop with a very shallow root system that is frequently irrigated and fertilized with high N rates to maximize yield. Converting from furrow-irrigated to drip-irrigated onion production may reduce N fertilizer needs, water inputs, and NO3-N leaching poten...

  2. Sustainable Irrigation Development in the White Volta Sub-Basin

    NARCIS (Netherlands)

    Ofosu, E.A.

    2011-01-01

    This study on sustainable irrigation development identified growing markets for irrigated products as an important driving force behind the expansion of irrigation which has given rise to new technologies. The new technologies have spread because they gave farmers direct control over water sources.

  3. Irrigation system management assisted by thermal imagery and spatial statistics

    Science.gov (United States)

    Thermal imaging has the potential to assist with many aspects of irrigation management including scheduling water application, detecting leaky irrigation canals, and gauging the overall effectiveness of water distribution networks used in furrow irrigation. Many challenges exist for the use of therm...

  4. A land suitability system for spate irrigation schemes in Eritrea

    NARCIS (Netherlands)

    Tesfai, M.H.

    2002-01-01

    Spate irrigation is a system used for wetting land prior to planting. Use is made of seasonal rivers (wadis) producing flash floods in the uplands, which are directed by structures to irrigate fields in the lowlands. A land suitability system for spate irrigation schemes in Eritrea was studied in th

  5. 21 CFR 886.4360 - Ocular surgery irrigation device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ocular surgery irrigation device. 886.4360 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4360 Ocular surgery irrigation device. (a) Identification. An ocular surgery irrigation device is a device intended to be suspended over...

  6. 21 CFR 876.5220 - Colonic irrigation system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Colonic irrigation system. 876.5220 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5220 Colonic irrigation system. (a) Identification. A colonic irrigation system is a device intended to instill water into the...

  7. 21 CFR 872.6510 - Oral irrigation unit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oral irrigation unit. 872.6510 Section 872.6510...) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6510 Oral irrigation unit. (a) Identification. An oral irrigation unit is an AC-powered device intended to provide a pressurized stream of water...

  8. Fertigation - Injecting soluble fertilizers into the irrigation system

    Science.gov (United States)

    Thomas D. Landis; Jeremy R. Pinto; Anthony S. Davis

    2009-01-01

    Fertigation (fertilization + irrigation) is the newest way for nursery managers to apply fertilizer, and has become a standard practice in container nurseries. Because of the inherent inefficient water distribution patterns in field irrigation systems, fertigation has not been widely used in bareroot nurseries. However, a bareroot nursery with a center-pivot irrigation...

  9. Technical descriptions of ten irrigation technologies for conserving energy

    Energy Technology Data Exchange (ETDEWEB)

    Harrer, B.J.; Wilfert, G.L.

    1983-05-01

    Technical description of ten technologies which were researched to save energy in irrigated agriculture are presented. These technologies are: well design and development ground water supply system optimization, column and pump redesign, variable-speed pumping, pipe network optimization, reduced-pressure center-pivot systems, low-energy precision application, automated gated-pipe system, computerized irrigation scheduling, and instrumented irrigation scheduling. (MHR)

  10. Identifying and locating land irrigated by center-pivot irrigation systems using satellite imagery

    Science.gov (United States)

    Hoffman, R. O.

    1980-01-01

    A methodology for using Landsat imagery for the identification and location of land irrigated by center-pivot irrigation systems is presented. The procedure involves the use of sets of Landsat band 5 imagery taken separated in time by about three weeks during the irrigation season, a zoom transfer scope and mylar base maps to record the locations of center pivots. Further computer processing of the data has been used to obtain plots of center-pivot irrigation systems and tables indicating the distribution and growth of systems by county for the state of Nebraska, and has been found to be in 95% agreement with current high-altitude IR photography. The information obtainable can be used for models of ground-water aquifers or resource planning.

  11. Fruit yield and quality of drip-irrigated tomato under deficit irrigation ...

    African Journals Online (AJOL)

    African Journal of Food, Agriculture, Nutrition and Development ... The competition for limited amount of world fresh water is increasing at a fast rate. ... The two tomato cultivars were exposed to four irrigation water deficit levels expressed as ...

  12. Irrigation frequency and timing influence pepper yields

    Science.gov (United States)

    Information on how fertilizer and irrigation affect production of vegetables can help growers improve resource use efficiency and profitability. Fertilizer was applied at the recommended rate and twice the recommended rate to bell and non-pungent jalapeno peppers, both Capsicum annuum L., in 2009 a...

  13. Using a System Model for Irrigation Management

    Science.gov (United States)

    de Souza, Leonardo; de Miranda, Eu; Sánchez-Román, Rodrigo; Orellana-González, Alba

    2014-05-01

    When using Systems Thinking variables involved in any process have a dynamic behavior, according to nonstatic relationships with the environment. In this paper it is presented a system dynamics model developed to be used as an irrigation management tool. The model involves several parameters related to irrigation such as: soil characteristics, climate data and culture's physiological parameters. The water availability for plants in the soil is defined as a stock in the model, and this soil water content will define the right moment to irrigate and the water depth required to be applied. The crop water consumption will reduce soil water content; it is defined by the potential evapotranspiration (ET) that acts as an outflow from the stock (soil water content). ET can be estimated by three methods: a) FAO Penman-Monteith (ETPM), b) Hargreaves-Samani (ETHS) method, based on air temperature data and c) Class A pan (ETTCA) method. To validate the model were used data from the States of Ceará and Minas Gerais, Brazil, and the culture was bean. Keyword: System Dynamics, soil moisture content, agricultural water balance, irrigation scheduling.

  14. Irrigation performance assessment in Crimea, Ukraine

    NARCIS (Netherlands)

    Pavlov, S.S.; Roerink, G.J.; Hellegers, P.J.G.J.; Popovych, V.F.

    2006-01-01

    After the collapse of the Soviet Union the performance of irrigated agriculture decreased drastically in Ukraine, due to problems related to the transition from a centrally planned economy to a market economy. Before formulating recommendations on required actions to modify this problematic situatio

  15. SANITARY SEWAGE REUSE IN AGRICULTURAL CROP IRRIGATION

    Directory of Open Access Journals (Sweden)

    Lidiane Bittencourt Barroso

    2011-10-01

    Full Text Available The water availability was exceeded by demand, becoming a limiting factor in irrigated agriculture. This study aimed to provide a general theoretical framework on the issue of water reuse for agricultural purposes. This is due to the fact that we need a prior knowledge of the state of the art concerning the matter. To that end, we performed a review of irrigated agriculture, the effects on cultivated land and the development of agricultural crops as well as aspects of security to protect groups at risk. The amount of macro and micronutrients in the effluent may reduce or eliminate the use of commercial fertilizers. And this addition of organic matter acts as a soil conditioner, increasing its capacity to retain water. Depending on the characteristics of sewage, the practice of irrigation for long periods may lead to accumulation of toxic compounds and the significant increase of salinity. The inhibition of plant growth by salinity may be due to osmotic effect, causing drought and / or specific effects of ions, which can cause toxicity or nutritional imbalance. The minimization of human exposure to the practice of agricultural reuse is based on a set of mitigation measures that must be implemented by the authorities responsible for operating and monitoring systems for water recycling. It is concluded that the use of sewage depends on management of irrigation, monitoring of soil characteristics and culture.

  16. COMMUNITY IRRIGATION DAMS IN THE UPPER EAST

    African Journals Online (AJOL)

    such as Unit Committee members, Assembly members or higher government authori- .... entails some system of rotation of irrigable land ownership between the ... work and the management procedures institutionalized and the outcomes. .... WUA has also been able to generate revenue through its membership registration.

  17. Irrigation performance assessment in Crimea, Ukraine

    NARCIS (Netherlands)

    Pavlov, S.S.; Roerink, G.J.; Hellegers, P.J.G.J.; Popovych, V.F.

    2006-01-01

    After the collapse of the Soviet Union the performance of irrigated agriculture decreased drastically in Ukraine, due to problems related to the transition from a centrally planned economy to a market economy. Before formulating recommendations on required actions to modify this problematic

  18. Cytotoxic effect of endodontic irrigants in vitro.

    Science.gov (United States)

    Bajrami, Donika; Hoxha, Veton; Gorduysus, Omer; Muftuoglu, Sevda; Zeybek, Nacije Dilara; Küçükkaya, Selen

    2014-03-10

    Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. The aim of this study was to assess the cytotoxic effect of NaOCl 3%, Chx 2%, and MTAD on rat periodontal ligament fibroblasts, at 0.1 and 100 µl/mL, using WST-1 colorimetric method. Rat ligamental fibroblasts were exposed to the irrigants and their viability was assessed after 1, 24, 48, and 72 h. The measurements were determined using WST-1 assay, using a micro ELISA reader. At 100 ml/L all 3 irrigants were strongly cytotoxic, although CHX was less so than NaOCl and MTAD. At the 0.1 ml/L concentration, NaOCl and MTAD were only moderately cytotoxic, whereas Chx was highly deleterious to cell viability at all time points. There was a significant influence of the dilution rate of the substance, because the odds ratio for cell viability being over 50% was increased 51 times between the 100 ml/L and 0.1 ml/L dilutions. It seems that irrigating solutions should be used at lower concentrations to enhance cell viability.

  19. Precision agriculture approach for improving cotton irrigation

    Science.gov (United States)

    Cotton is a vital part of the southeast Missouri economy and while we’re not currently facing problems with groundwater decline, it’s still important to apply the right amount of irrigation at the proper time. We currently have several projects at the Fisher Delta Research Center with that aim. For ...

  20. Reuse of drainage water from irrigated areas

    NARCIS (Netherlands)

    Willardson, L.S.; Boels, D.; Smedema, L.K.

    1997-01-01

    Increasing competition for water of good quality and the expectation that at least half of the required increase in food production in the near-future decades must come from the world's irrigated land requires to produce more food by converting more of the diverted water into food. Reuse of the

  1. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  2. Decision support for optimised irrigation scheduling

    NARCIS (Netherlands)

    Anastasiou, A.; Sawas, D.; Pasgianos, G.; Sigrimis, N.; Stanghellini, C.; Kempkes, F.L.K.

    2009-01-01

    The system, developed under the FLOW-AID (an FP6 project), is a farm level water management system of special value in situations where the water availability and quality is limited. This market-ready precision irrigation management system features new models, hardware and software. The hardware pla

  3. Irrigation timing and fertilizer rate in peppers

    Science.gov (United States)

    Excessive rain fall might leach nutrients from the soil or cause producers to not supply irrigation to pepper (Capsicum sp.). Fertilizer at 150 or 300 lb/acre of triple 17 NPK, the lower rate is the recommended rate, was supplied to either bell, cv. Jupiter, or non-pungent jalapeno, cv. Pace 105, pe...

  4. Philippines : PPP Options in Irrigation Sector

    OpenAIRE

    World Bank

    2013-01-01

    This study proposes an analytical framework to determine the extent to which Public-Private Partnership (PPP) is a viable and effective business option for developing and modernizing the irrigation sector in the Philippines. It focuses on: (a) assessing and providing recommendations to address the policy, regulatory and institutional constraints that limit the recourse to PPP as a tool to ...

  5. Comparative inflammatory effect of antiseptic irrigating solutions against conventional irrigation with sodium chloride in rats.

    OpenAIRE

    Rodríguez Alfaro, Miguel; Profesor Asociado del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Chumpitaz Cerrate, Víctor; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Burga Sánchez, Jonny; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Medicina de la UCSUR.; Arroyo Acevedo, Jorge; Profesor Principal del Departamento Académico de Ciencias Básicas de la Facultad de Medicina de la UNMSM.; Ramón Rosales, Jorge; Profesor Auxiliar del departamento Académico de Ciencias Básicas de la Facultad de Estomatología de la UCSUR.; Aguirre Siancas, Elías; Profesor Auxiliar del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.; Cabrejos Álvarez, José; Profesor de la Catedra de Cirugia Bucal y Máxilofacial de la Facultad de Estomatología de la UIGV.; Zegarra Cuya, Juan; Ex-Profesor del Departamento Académico de Ciencias Básicas de la Facultad de Odontología de la UNMSM.

    2014-01-01

    The aim of this study was to demonstrate that the use of irrigating solutions in surgical procedures does not alter both inflammation processes and tissue repair. Four (04) groups were formed containing 15 rats each. After being dosed with general anaesthesia, they underwent osteotomy in the tibia with tungsten carbide burs and irrigation for 15 seconds, using the following solutions in each group: A) 0,12 % chlorhexidine with cetylpyridinium 0,05 %, B) 0,12 % chlorhexidine with aspartame; C)...

  6. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system,

  7. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system, wh

  8. Irrigation et paludisme : un couple infernal?

    Directory of Open Access Journals (Sweden)

    Mergeai, G.

    2016-01-01

    Full Text Available Irrigation and Malaria - a Terrible Combination?. Increasing agricultural productivity is a priority in most of the developing countries and using irrigation is one of the most efficient ways of achieving this goal. Almost half a billion people in the world contract malaria every year and approximately one million die as a result. The majority of these victims are farmers or members of their families. In infected areas, malaria continues to have major negative impacts on agricultural productivity. For example, in the Equateur province of the DRC, after access to production means, fevers are considered the second biggest obstacle to the development of agricultural activities. In the Ivory Coast, a study has shown that growers suffering from malaria were about half as productive as their healthy colleagues. The disease often strikes at the start of the rainy season when work begins again in the fields. It reduces the amount of land cultivated and affects the amount of care taken with crops. Agricultural practices influence the risk of contracting malaria. Irrigation, in particular, can encourage the proliferation of vectors of the disease and make it more likely to spread. This tendency can be observed in many locations where irrigated rice production is on the increase. Paradoxically, however, an increased number of mosquitoes does not systematically result in more malaria. In Ethiopia, malaria is more prevalent close to the micro-dams sponsored by the government, whereas, in Tanzania, there is less malaria in irrigated areas. Various theories can be put forward in order to explain this paradox. In particular, increased income due to higher rice yields enables farmers to purchase insecticide-treated mosquito nets. It also allows them to eat better, which strengthens their immune systems. It also appears that the negative impact of irrigation systems is greater in areas, in which immunity levels were low in the population prior to the creation of

  9. The role of energy audits in irrigated areas. The case of Fuente Palmera irrigation district (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Carrillo-Cobo, M. T.; Rodriguez-Diaz, J. A.; Camacho-Poyato, E.

    2010-07-01

    In recent years, energy consumption for irrigation has grown rapidly. Actually, nowadays energy represents a significant percentage on the total water costs in irrigation districts using energy to pressurize water. With the aim of improving energy efficiency in the Fuente Palmera irrigation district, was applied the protocol for conducting energy audits in irrigation districts developed by Spanish Institute for Diversification and Energy Savings (IDAE). The irrigated area organized in two independent sectors according to a homogeneous elevation criterion is analyzed and simulated. The potential energy savings derived from this measure was evaluated. For this purpose, a model based on the hydraulic simulator EPANET has been carried out. Its energy demand was estimated in 1,360 kWh ha-1 and its overall energy efficiency in 56%. The district was globally classified in group C (normal). Results show potential energy savings of up to 12% were obtained when the network was divided in sectors and farmers organized in two irrigation shifts. Further energy savings could be achieved by improving the hydraulic structures, such as the pumping station or the network layout and dimensions. (Author) 26 refs.

  10. Glyphosate transport through weathered granite soils under irrigated and non-irrigated conditions--Barcelona, Spain.

    Science.gov (United States)

    Candela, Lucila; Caballero, Juan; Ronen, Daniel

    2010-05-15

    The transport of Glyphosate ([N-phosphonomethyl] glycine), AMPA (aminomethylphosphonic acid, CH(6)NO(3)P), and Bromide (Br(-)) has been studied, in the Mediterranean Maresme area of Spain, north of Barcelona, where groundwater is located at a depth of 5.5m. The unsaturated zone of weathered - granite soils was characterized in adjacent irrigated and non-irrigated experimental plots where 11 and 10 boreholes were drilled, respectively. At the non irrigated plot, the first half of the period was affected by a persistent and intense rainfall. After 69 days of application residues of Glyphosate up to 73.6 microgg(-1) were detected till a depth of 0.5m under irrigated conditions, AMPA, analyzed only in the irrigated plot was detected till a depth of 0.5m. According to the retardation coefficient of Glyphosate as compared to that of Br(-) for the topsoil and subsoil (80 and 83, respectively) and the maximum observed migration depth of Br(-) (2.9 m) Glyphosate and AMPA should have been detected till a depth of 0.05 m only. Such migration could be related to the low content of organic matter and clays in the soils; recharge generated by irrigation and heavy rain, and possible preferential solute transport and/or colloidal mediated transport. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Treatment of ammonia by catalytic wet oxidation process over platinum-rhodium bimetallic catalyst in a trickle-bed reactor: effect of pH.

    Science.gov (United States)

    Hung, Chang-Mao; Lin, Wei-Bang; Ho, Ching-Lin; Shen, Yun-Hwei; Hsia, Shao-Yi

    2010-08-01

    This work adopted aqueous solutions of ammonia for use in catalytic liquid-phase reduction in a trickle-bed reactor with a platinum-rhodium bimetallic catalyst, prepared by the co-precipitation of chloroplatinic acid (H2PtCl6) and rhodium nitrate [Rh(NO3)3]. The experimental results demonstrated that a minimal amount of ammonia was removed from the solution by wet oxidation in the absence of any catalyst, while approximately 97.0% of the ammonia was removed by wet oxidation over the platinum-rhodium bimetallic catalyst at 230 degrees C with an oxygen partial pressure of 2.0 MPa. The oxidation of ammonia has been studied as a function of pH, and the main reaction products were determined. A synergistic effect is manifest in the platinum-rhodium bimetallic structure, in which the material has the greatest capacity to reduce ammonia. The reaction pathway linked the oxidizing ammonia to nitric oxide, nitrogen, and water.

  12. Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction.

    Science.gov (United States)

    Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A; García, Juan

    2013-01-15

    Active nickel catalysts (7 wt%) supported over Mg-Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min(-1) and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min(-1), respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T(r)=0.098 g(Ni) min mL(-1). After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T(r)=0.098 g(Ni) min mL(-1), attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity.

  13. Simulated errors in deep drainage beneath irrigated settings: Partitioning vegetation, texture and irrigation effects using Monte Carlo

    Science.gov (United States)

    Gibson, J. P.; Gates, J. B.; Nasta, P.

    2014-12-01

    Groundwater in irrigated regions is impacted by timing and rates of deep drainage. Because field monitoring of deep drainage is often cost prohibitive, numerical soil water models are frequently the main method of estimation. Unfortunately, few studies have quantified the relative importance of likely error sources. In this study, three potential error sources are considered within a Monte Carlo framework: water retention parameters, rooting depth, and irrigation practice. Error distributions for water retention parameters were determined by 1) laboratory hydraulic measurements and 2) pedotransfer functions. Error distributions for rooting depth were developed from literature values. Three irrigation scheduling regimes were considered: one representing pre-scheduled irrigation ignoring preceding rainfall, one representing pre-scheduled irrigation that was altered based on preceding rainfall, and one representing algorithmic irrigation scheduling informed by profile matric potential sensors. This approach was applied to an experimental site in Nebraska with silt loam soils and irrigated corn for 2002-2012. Results are based on Six Monte-Carlo simulations, each consisting of 1000 Hydrus 1D simulations at daily timesteps, facilitated by parallelization on a 12-node computing cluster. Results indicate greater sensitivity to irrigation regime than to hydraulic or vegetation parameters (median values for prescheduled irrigation, prescheduled irrigation altered by rainfall, and algorithmic irrigation were 310 ,100, and 110 mm/yr, respectively). Error ranges were up to 700% higher for pedotransfer functions than for laboratory-measured hydraulic functions. Deep drainage was negatively correlated with alpha and maximum root zone depth and, for some scenarios, positively correlated with n. The relative importance of error sources differed amongst the irrigation scenarios because of nonlinearities amongst parameter values, profile wetness, and deep drainage. Compared to pre

  14. Biochar enhances yield and quality of tomato under reduced irrigation

    DEFF Research Database (Denmark)

    Saleem Akhtar, Saqib; Li, Guitong; Andersen, Mathias Neumann

    2014-01-01

    tBiochar is an amendment that can be used for enhancing soil water storage which may increase cropproductivity. The objective of this study was to investigate the effects of biochar on physiology, yield andquality of tomato under different irrigation regimes. From early flowering to fruit maturity...... stages, theplants were subjected to full irrigation (FI), deficit irrigation (DI) and partial root-zone drying irrigation(PRD) and two levels of biochar (0% and 5% by weight). In FI, the plants were irrigated daily to pot waterholding capacity while in DI and PRD, 70% of FI was irrigated on either...... the whole or one side of the pots,respectively. In PRD, irrigation was switched between sides when the soil water content of the dry sidedecreased to 15%. The results showed that addition of biochar increased the soil moisture contents in DIand PRD, which consequently improved physiology, yield, and quality...

  15. Sediment and nutrient losses from an irrigated watershed.

    Science.gov (United States)

    Bjorneberg, D.; Ippolito, J.

    2011-12-01

    Irrigated agriculture is an essential part of stable food and fiber production. However, water returning from irrigated watersheds can contain excess sediment, nutrients and salts. Applying polyacrylamide to furrow irrigated fields reduces erosion 60 to 90%. Converting from furrow irrigation to sprinkler irrigation eliminates planned irrigation runoff necessary for uniform water application. Installing sediment ponds removes 50 to 80% of the suspended sediment from water before it flows back to major water bodies. In southern Idaho, irrigation watershed monitoring showed that implementing these conservation practices has reduced average suspended sediment loss from 460 kg/ha in 1970 to less than 100 kg/ha in 2005. These practices, however, have had less effect on soluble nutrients. Median nitrate concentrations have almost doubled from 1970 to 2005. Current research is focusing on identifying practices to reduce soluble nutrient losses.

  16. ASSESSMENT OF IRRIGATION EFFICIENCIES UNDER CENTRAL ANATOLIA CONDITIONS

    Directory of Open Access Journals (Sweden)

    Yusuf Ersoy Yildirim

    2016-12-01

    Full Text Available Turkey is located within semi-arid climate zone and large portion of the country experience water deficits. Thus, efficient water use has become a significand issue in agricultural practices. Current global warming and climate change have aggravated such deficiencies. Konya province is located right at the center of Central Anatolia region and mostly groundwater is used in irrigations. Excessive groundwater withdrawals drop groundwaters levels and also increase energy costs. Although farmers pay quite high sums for energy, they were not using water efficiently and thus were not able to get desired benefits from the irrigations. In this study, irrigation practices of an irrigation cooperative were assessed and compared with optimum irrigation programs created through IRSIS irrigation scheduling software. It was concluded that all irrigation practices of the region were wrong and way behind the optimum ones.

  17. Seismic Risk Management of Irrigation System in an Earthquake

    Science.gov (United States)

    Kobayashi, Akira; Hayashi, Takuma; Yamamoto, Kiyohito; Kiyama, Shoichi

    A risk analysis method of an irrigation system in an earthquake is proposed. The irrigation system consists of irrigation tanks and canals. The damage probability of the irrigation tanks and canals was obtained from both numerical simulation and actual disaster data from the Mid Niigata prefecture earthquake. The losses due to reduced crop yield, restoration and secondary disaster were considered in the risk assessment. The probability of annual peak ground acceleration was introduced from the earthquake records in Niigata prefecture. To reduce the damage probability, an enhanced foundation of canals on flat land and widening of the embankment were applied. It was found that the countermeasures for the irrigation tanks were more effective than those for the canals. In the case of a large secondary disaster of the irrigation system on flat land, the countermeasures for the irrigation system were very effective.

  18. Two challenges for U.S. irrigation due to climate change: increasing irrigated area in wet states and increasing irrigation rates in dry states.

    Directory of Open Access Journals (Sweden)

    Robert I McDonald

    Full Text Available Agricultural irrigation practices will likely be affected by climate change. In this paper, we use a statistical model relating observed water use by U.S. producers to the moisture deficit, and then use this statistical model to project climate changes impact on both the fraction of agricultural land irrigated and the irrigation rate (m³ ha⁻¹. Data on water withdrawals for US states (1985-2005 show that both quantities are highly positively correlated with moisture deficit (precipitation--PET. If current trends hold, climate change would increase agricultural demand for irrigation in 2090 by 4.5-21.9 million ha (B1 scenario demand: 4.5-8.7 million ha, A2 scenario demand: 9.1-21.9 million ha. Much of this new irrigated area would occur in states that currently have a wet climate and a small fraction of their agricultural land currently irrigated, posing a challenge to policymakers in states with less experience with strict regulation of agriculture water use. Moreover, most of this expansion will occur in states where current agricultural production has relatively low market value per hectare, which may make installation of irrigation uneconomical without significant changes in crops or practices by producers. Without significant increases in irrigation efficiency, climate change would also increase the average irrigation rate from 7,963 to 8,400-10,415 m³ ha⁻¹ (B1 rate: 8,400-9,145 m³ ha⁻¹, A2 rate: 9,380-10,415 m³ ha⁻¹. The irrigation rate will increase the most in states that already have dry climates and large irrigation rates, posing a challenge for water supply systems in these states. Accounting for both the increase in irrigated area and irrigation rate, total withdrawals might increase by 47.7-283.4 billion m³ (B1 withdrawal: 47.7-106.0 billion m³, A2 withdrawal: 117.4-283.4 billion m³. Increases in irrigation water-use efficiency, particularly by reducing the prevalence of surface irrigation, could eliminate the

  19. Groundwater use for irrigation – a global inventory

    Directory of Open Access Journals (Sweden)

    S. Siebert

    2010-10-01

    Full Text Available Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha, China (19 million ha and the USA (17 million ha. Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.

  20. Groundwater use for irrigation – a global inventory

    Directory of Open Access Journals (Sweden)

    S. Siebert

    2010-06-01

    Full Text Available Irrigation is the most important water use sector accounting for about 70% of the global freshwater withdrawals and 90% of consumptive water uses. While the extent of irrigation and related water uses are reported in statistical databases or estimated by model simulations, information on the source of irrigation water is scarce and very scattered. Here we present a new global inventory on the extent of areas irrigated with groundwater, surface water or non-conventional sources, and we determine the related consumptive water uses. The inventory provides data for 15 038 national and sub-national administrative units. Irrigated area was provided by census-based statistics from international and national organizations. A global model was then applied to simulate consumptive water uses for irrigation by water source. Globally, area equipped for irrigation is currently about 301 million ha of which 38% are equipped for irrigation with groundwater. Total consumptive groundwater use for irrigation is estimated as 545 km3 yr−1, or 43% of the total consumptive irrigation water use of 1 277 km3 yr−1. The countries with the largest extent of areas equipped for irrigation with groundwater, in absolute terms, are India (39 million ha, China (19 million ha and the United States of America (17 million ha. Groundwater use in irrigation is increasing both in absolute terms and in percentage of total irrigation, leading in places to concentrations of users exploiting groundwater storage at rates above groundwater recharge. Despite the uncertainties associated with statistical data available to track patterns and growth of groundwater use for irrigation, the inventory presented here is a major step towards a more informed assessment of agricultural water use and its consequences for the global water cycle.

  1. The fluid mechanics of root canal irrigation.

    Science.gov (United States)

    Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

    2010-12-01

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  2. Effects of Irrigation and Fertilizer on Soil and Water Quality%施肥和灌溉对土壤和水质的影响

    Institute of Scientific and Technical Information of China (English)

    刘向华; 阳树英

    2004-01-01

    Reviews five important methods to monitor water quality,ten guidelines for selecting soil physical,chemical and biological quality indicators and how these parameters are affected by typical irrigation systems and fertilizer types.It is found that:rain-fed,flood irrigation,drip irrigation,trickle irrigation and sprinkler irrigation have variable water use efficiencies and variable effects on soil.Soil biological and biochemical variables are considered to be essential to measure changes in soil quality.Soil quality parameters such as soil aggregate size,stability and solum thickness,bulk density,infiltration rate,soil organic matter,microbial biomass and increased nutrient availability are improved by fertilization,though soil pH,total organic carbon and basic cation contents may be decreased.Excessive fertilization can cause soil quality decline and serious environment problems.Improved lysimeters without edge flow can be used to measure accurately the effects of fertilizer and irrigation on drainage water quality.The conclusions are that water quality,soil quality and productive capacity can be maintained and improved in the long-term by careful use of fertilizers and irrigation.%论述了选择土壤物理、化学和生物学性质参数的十项标准,五种重要的监测水质的方法,以及施肥和灌溉对土壤和水质的影响.雨养、漫灌、滴灌、细流灌和喷灌具有不同的水利用率,且对土壤物理、化学和生物学性质的影响各异.土壤生物化学性质是重要的监测土壤变化的参数.虽然施肥可能降低土壤pH值、总有机碳和盐基离子浓度,但土壤的其他指标如土壤结构、有机质、土壤微生物和养分状况都得以改良.过量施肥会使土质退化并带来严重的环境问题.消除了边际效应的土壤测渗计能够准确地监测施肥和灌溉对水质的影响.所综述研究表明如果施肥得当,土壤和水质可以改善或长期保持良性循环.

  3. Comparison of a continuous ultrasonic irrigation device and conventional needle irrigation in the removal of root canal debris.

    Science.gov (United States)

    Curtis, Tyson O; Sedgley, Christine M

    2012-09-01

    The purpose of this in vitro study was to compare a continuous ultrasonic irrigation device (VPro StreamClean System [VSS], Vista Dental Products, Racine, WI) with conventional needle irrigation when used as a final irrigation procedure to debride the apical region of the root canal. The null hypothesis that there is no difference was tested. Root canals of matched pairs (N = 20) of extracted human teeth were prepared to an apical size of 36/.04 using Profile series 29/.04 rotary files (Dentsply Tulsa Dental, Tulsa, OK) with 6% sodium hypochlorite (NaOCl) irrigation. One tooth of each pair was randomly assigned to receive final irrigation with either VSS or conventional needle irrigation. The gauge of the needle (#30), the irrigation cycles (ie, 5 mL NaOCl, 5 mL 15% EDTA, and 5 mL NaOCl), the irrigant flow rate (5 mL/min), and needle depth placement (1 mm from the working length [WL]) were experimental constants. Serial sections were obtained at 1 and 3 mm from the WL, stained with hematoxylin-eosin, and viewed at 100× magnification for the presence of debris. The percentage of debris in the canal lumen after VSS or conventional needle irrigation was compared by using the Wilcoxon matched pairs test. There was significantly less debris in the VSS group compared with the conventional needle irrigation group at the 1-mm level (1.50% [VSS] vs 9.90% [conventional needle irrigation], P = .0001) and the 3-mm level (0.45% [VSS] vs 5.16% [conventional needle irrigation], P = .0014). The null hypothesis was rejected. Final irrigation with the VSS compared with conventional needle irrigation delivery resulted in significantly less debris present in root canals at 1 and 3 mm from the WL. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Development of Strategies for Sustainable Irrigation Water Management in Russia

    Science.gov (United States)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2013-04-01

    During 1960 - 1990 years irrigated areas in Russia have increased rapidly, helping to boost agricultural output. Although the impressive achievements of irrigation in this period its large experience indicates problems and failures of irrigation water management. In addition to large water use and low irrigation water efficiency, environmental concerns (excessive water depletion, water quality reduction, water logging, soil degradation) are usually considered like the most significant problem of the irrigation sector. Despite of considerable shrinking of irrigated areas in Russia and decreasing of water withdrawal for irrigation purposes during two last decades a degradation of environment as well as degradation of soil and water resources in irrigated areas was prolonged and will probably continue if current irrigation practices are maintained. Nowadays, in different regions of Russia there are societal demand to restore agricultural irrigation in Russia as answer to challenges from climate pattern changes and degradation of land & water resources. In the respect of these demands there is a need to develop strategies for sustainability of agricultural irrigation in Russia that should be based on three main societal objectives: costeffective use of water in irrigated agriculture at farm level, and satisfactory preserving the natural environment. Therefore sustainable irrigation water management is not only an objective at farm level but also an overall goal at the local and regional as well. A way to achieve sustainability in irrigation water management is to solve the local conflicts arising from the interactions between water use at irrigation areas and surrounding environment. Thus should be based on the development of irrigation framework program including on the irrigation water management issues, policies & decisions making at federal and regional levels should be based on the indicators of environment & irrigation water efficiency monitoring promoting the

  5. Online decision support system for surface irrigation management

    Science.gov (United States)

    Wang, Wenchao; Cui, Yuanlai

    2017-04-01

    Irrigation has played an important role in agricultural production. Irrigation decision support system is developed for irrigation water management, which can raise irrigation efficiency with few added engineering services. An online irrigation decision support system (OIDSS), in consist of in-field sensors and central computer system, is designed for surface irrigation management in large irrigation district. Many functions have acquired in OIDSS, such as data acquisition and detection, real-time irrigation forecast, water allocation decision and irrigation information management. The OIDSS contains four parts: Data acquisition terminals, Web server, Client browser and Communication system. Data acquisition terminals are designed to measure paddy water level, soil water content in dry land, ponds water level, underground water level, and canals water level. A web server is responsible for collecting meteorological data, weather forecast data, the real-time field data, and manager's feedback data. Water allocation decisions are made in the web server. Client browser is responsible for friendly displaying, interacting with managers, and collecting managers' irrigation intention. Communication system includes internet and the GPRS network used by monitoring stations. The OIDSS's model is based on water balance approach for both lowland paddy and upland crops. Considering basic database of different crops water demands in the whole growth stages and irrigation system engineering information, the OIDSS can make efficient decision of water allocation with the help of real-time field water detection and weather forecast. This system uses technical methods to reduce requirements of user's specialized knowledge and can also take user's managerial experience into account. As the system is developed by the Browser/Server model, it is possible to make full use of the internet resources, to facilitate users at any place where internet exists. The OIDSS has been applied in

  6. Genetic base of Brazilian irrigated rice cultivars

    Directory of Open Access Journals (Sweden)

    Hudson de Oliveira Rabelo

    2015-08-01

    Full Text Available The aim of this study was to estimate the genetic base of Brazilian irrigated rice cultivars released in the period from 1965 to 2012. The genealogies of the cultivars were obtained based on information from marketing folders, websites, crossings records, and scientific articles. The following factors were calculated: relative genetic contribution (RGC, accumulated genetic contribution (AGC, frequency (in percentage of each ancestor in the genealogy (FAG, number of ancestors that constitute each cultivar (NAC,number of ancestors responsible for 60%, 70%, 80% and 90% of the genetic base (NAGB, and average number of ancestor per cultivar (ANAC. The cultivars were also grouped based on the period of release (1965-1980, 1981-1990, 1991-2000 and 2001-2012. For each grouping, the previously described factors were also estimated. A total of 110 cultivars were studied and it was concluded that the genetic base of Brazilian irrigated rice cultivars is narrow.

  7. Irrigants in non-surgical endodontic treatment.

    Science.gov (United States)

    Regan, John D; Fleury, Alex A P

    2006-01-01

    This paper highlights that one of the main goals of root canal treatment is the elimination of microorganisms from the contaminated root canal system. Instrumentation alone will not allow for adequate debridement and disinfection of the complex and diverse root canal system. Chemomechanical debridement is required. The importance of the use of irrigants during non-surgical root canal treatment has frequently been neglected both during instruction of dental students and later in the clinical practice of endodontics. The article highlights 'shape, clean and fill' vs. 'clean, shape and fill' to enable chemomechanical debridement. Our protocol advises mechanical debridement and copious irrigation for a minimum of twenty minutes with 2.5% to 6% solutions of sodium hypochlorite, followed by a rinse with a 17% solution of ethylenediaminetetraacetic acid and a final rinse with 2% chlorhexidine. The canals are dried with high volume aspirators and sterile paper points.

  8. DEVELOPMENT OF WATER CIRCULATION MODEL INCLUDING IRRIGATION

    Science.gov (United States)

    Kotsuki, Shunji; Tanaka, Kenji; Kojiri, Toshiharu; Hamaguchi, Toshio

    It is well known that since agricultural water withdrawal has much affect on water circulation system, accurate analysis of river discharge or water balance are difficult with less regard for it. In this study, water circulation model composed of land surface model and distributed runoff model is proposed at 10km 10km resolution. In this model, irrigation water, which is estimated with land surface model, is introduced to river discharge analysis. The model is applied to the Chao Phraya River in Thailand, and reproduced seasonal water balance. Additionally, the discharge on dry season simulated with the model is improved as a result of including irrigation. Since the model, which is basically developed from global data sets, simulated seasonal change of river discharge, it can be suggested that our model has university to other river basins.

  9. Saline water irrigation of quinoa and chickpea

    DEFF Research Database (Denmark)

    Hirich, A.; Jelloul, A.; Choukr-Allah, R.

    2014-01-01

    A pot experiment was conducted in the south of Morocco to evaluate the response of chickpea and quinoa to different irrigation water salinity treatments (1, 4, 7 and 10 dS m-1 for chickpea and 1, 10, 20 and 30 dS m-1 for quinoa). Increasing salinity affected significantly (P ... and height and caused delay and reduction in seed emergence, quinoa was shown to be more resistant than chickpea. Dry biomass, seed yield, harvest index and crop water productivity were affected significantly (P ... and seed yield for both quinoa and chickpea while increasing salinity resulted in increase - in the case of quinoa - and decrease - in the case of chickpea - in harvest index and crop water productivity. Na+ and Na+/K+ ratio increased with increasing irrigation water salinity, while K+ content decreased...

  10. 领导学研究中的下行传递效应:表现、机制与条件%The Trickle-Down Effect in Leadership Research:A Review and Prospect

    Institute of Scientific and Technical Information of China (English)

    王震; 许灏颖; 杜晨朵

    2015-01-01

    The inquiry of the trickle-down effect is booming and developing into a new realm in the leadership study. Trickle-down effect refers to a top-down process in which leaders’ trait, cognition, affect, attitude and behavior induce the similar responses of followers and/or groups. Based on 62 independent empirical investigations reported in 50 articles, we found: (1) Trickle-down effect can be classified into six types according to the nature (state-like, affects, cognitions, attitudes, behaviors, relationships) of the transmitted variables; (2)Trickle-down effect can further influence the attitudes, behaviors and performance of followers, teams and other stakeholders; (3)There are mainly five theories explaining the occurrence of trickle-down effect, namely emotion contagion/affective event theory, social learning theory, social exchange theory, social identity theory and social information processing theory; (4) The strength of trickle-down effect depends on some specific leader, follower/team, and contextual attributes.%在领导学研究领域,对下行传递效应的探讨逐渐兴起并取得了一系列进展。下行传递效应是指在组织情境下,领导者的特征和行为通过组织垂直的管理层次自上而下地进行传递,最终引发下属和团队相同特征和行为的过程。从现有研究(50篇实证文献、62个独立研究)来看:(1)研究者主要考察了类状态特征、情感、认知、态度、行为和关系6类下行传递效应;(2)领导-下属/团队间的下行传递效应会进一步影响下属、团队以及其他利益相关者(如顾客)的态度、行为和绩效;(3)下行传递效应主要通过情绪传染和情感事件、社会交换、社会认同、社会学习、社会信息加工机制而发生;(4)下行传递效应的发生具有一定的边界条件,其效应强弱受领导、下属/团队和情境特征影响。未来研究应扩展下行传递效应的研究内容,深入讨论这种

  11. Review of root canal irrigant delivery techniques and devices

    Directory of Open Access Journals (Sweden)

    Yeon-Jee Yoo

    2011-05-01

    Full Text Available Introduction Eliminating the residual debris and bacteria in the root canal system is one of the main purposes of the endodontic treatment. However, the complexity on the anatomy of the root canal system makes it difficult to eliminate the bacterial biofilm existing along the root canal surface and necrotic pulp tissue by mechanical instrumentation and chemical irrigation. Recently, more effective irrigant delivery systems for root canal irrigation have been developed. The purpose of this review was to present an overview of root canal irrigant delivery techniques and devices available in endodontics. Review The contents of this paper include as follows; - syringe-needle irrigation, manual dynamic irrigation, brushes - sonic and ultrasonic irrigation, passive ultrasonic irrigation, rotary brush, RinsEndo, EndoVac, Laser Conclusion Though technological advances during the last decade have brought to fruition new agitation devices that rely on various mechanisms, there are few evidence based study to correlate the clinical efficacy of these devices with improved outcomes except syringe irrigation with needle and ultrasonic irrigation. The clinicians should try their best efforts to deliver antimicrobial and tissue solvent solutions in predictable volumes safely to working length.

  12. Effects of irrigation efficiency on chemical transport processes

    Institute of Scientific and Technical Information of China (English)

    WANG Kang; ZHANG RenDuo; SHENG Feng

    2009-01-01

    Irrigation practices greatly affect sustainable agriculture development.In this study, we investigated the effects of irrigation efficiency on water flow and chemical transport in soils, which had significant impact on the environment.Field dye staining experiments were conducted at different soils with various irrigation amount.Image analysis was conducted to study the heterogeneous flow patterns and their relationships with the irrigation efficiency.Irrigation efficiency and its environmental effects were evaluated using various indictors, including application efficiency, deep percolation ratio, storage effi-ciency, and uniformity.Under the same irrigation condition, soil chemical distributions were more het-erogeneous than soil water distributions.The distributions were mainly affected by soil texture, initial soil water content, and irrigation amount.Storage efficiency, irrigation uniformity, and deep percolation ratio increased with irrigation amount.Since the chemical distribution uniformity was lower than the water uniformity, the amount of chemical leaching increased sharply with decrease of irrigation uni-formity, which resulted in high environmental risks of groundwater pollution.

  13. Rice photosynthetic productivity and PSII photochemistry under nonflooded irrigation.

    Science.gov (United States)

    He, Haibing; Yang, Ru; Jia, Biao; Chen, Lin; Fan, Hua; Cui, Jing; Yang, Dong; Li, Menglong; Ma, Fu-Yu

    2014-01-01

    Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM), furrow irrigation with nonmulching (FIN), and drip irrigation with plastic mulching (DI). Compared with the conventional flooding (CF) treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN), lower maximum quantum yield (Fv/Fm), and lower effective quantum yield of PSII photochemistry (ΦPSII). And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC). Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA) were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  14. Climate Change Impacts of Irrigation on the Central High Plains

    Science.gov (United States)

    Cotterman, K. A.; Kendall, A. D.; Basso, B.; Hyndman, D. W.

    2015-12-01

    Since the 1940s, the High Plains Aquifer (HPA) has been pivotal for irrigation over the Central High Plains (CHP), a region spanning parts of five states in the central U.S.. Today after decades of over-pumping, many areas of the CHP are no longer able to irrigate due to localized depletion of the HPA. With a range of global climate models predicting an increase in temperature and decrease in growing-season precipitation for the CHP, demand for irrigation is likely to increase and exacerbate drawdown and depletion of the aquifer. Here we apply the Landscape Hydrology Model (LHM) coupled with the crop simulation model SALUS to simulate irrigation water use in response to historical climate and land use. This model is validated using historical groundwater levels. We then simulate future climate scenarios to predict how irrigation demand and water availability will alter the hydrology of the CHP. This study provides a predictive relationship of future irrigation demand linked to both climate change and agricultural management, and presents a modeling approach to answer two questions: How will future climate change affect irrigation demand? How will climate change and irrigation demand affect groundwater availability for the future? Different climate scenarios based on the representative concentration pathways (RCPs) are used to simulate the impact of different projected future climate conditions through the year 2100. By examining predicted groundwater levels along with saturated thickness we analyze where irrigation is likely to be viable in the future and compare this to current irrigation extent.

  15. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    Directory of Open Access Journals (Sweden)

    Jochen Hemming

    2009-04-01

    Full Text Available Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of efficient irrigation systems, which includes the implementation of a suitable method for precise scheduling. At the farm level, irrigation is generally scheduled based on the grower’s experience or on the determination of soil water balance (weather-based method. An alternative approach entails the measurement of soil water status. Expensive and sophisticated root zone sensors (RZS, such as neutron probes, are available for the use of soil and plant scientists, while cheap and practical devices are needed for irrigation management in commercial crops. The paper illustrates the main features of RZS’ (for both soil moisture and salinity marketed for the irrigation industry and discusses how such sensors may be integrated in a wireless network for computer-controlled irrigation and used for innovative irrigation strategies, such as deficit or dual-water irrigation. The paper also consider the main results of recent or current research works conducted by the authors in Tuscany (Italy on the irrigation management of container-grown ornamental plants, which is an important agricultural sector in Italy.

  16. Rice Photosynthetic Productivity and PSII Photochemistry under Nonflooded Irrigation

    Directory of Open Access Journals (Sweden)

    Haibing He

    2014-01-01

    Full Text Available Nonflooded irrigation is an important water-saving rice cultivation technology, but little is known on its photosynthetic mechanism. The aims of this work were to investigate photosynthetic characteristics of rice during grain filling stage under three nonflooded irrigation treatments: furrow irrigation with plastic mulching (FIM, furrow irrigation with nonmulching (FIN, and drip irrigation with plastic mulching (DI. Compared with the conventional flooding (CF treatment, those grown in the nonflooded irrigation treatments showed lower net photosynthetic rate (PN, lower maximum quantum yield (Fv/Fm, and lower effective quantum yield of PSII photochemistry (ΦPSII. And the poor photosynthetic characteristics in the nonflooded irrigation treatments were mainly attributed to the low total nitrogen content (TNC. Under non-flooded irrigation, the PN, Fv/Fm, and ΦPSII significantly decreased with a reduction in the soil water potential, but these parameters were rapidly recovered in the DI and FIM treatments when supplementary irrigation was applied. Moreover, The DI treatment always had higher photosynthetic productivity than the FIM and FIN treatments. Grain yield, matter translocation, and dry matter post-anthesis (DMPA were the highest in the CF treatment, followed by the DI, FIM, and FIN treatments in turn. In conclusion, increasing nitrogen content in leaf of rice plants could be a key factor to improve photosynthetic capacity in nonflooded irrigation.

  17. Effect of three different irrigation solutions applied by passive ultrasonic irrigation

    Directory of Open Access Journals (Sweden)

    Carmen Llena

    2015-05-01

    Full Text Available Objectives This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI. Materials and Methods Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl, 2% chlorhexidine (Group B, CHX and saline solution (Group C, control group were applied with Irrisafe 20 tips (Acteon and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM. The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. Results In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05, but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. Conclusions NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.

  18. Comparative anti-microbial efficacy of Azadirachta indica irrigant with standard endodontic irrigants: A preliminary study

    Directory of Open Access Journals (Sweden)

    Arindam Dutta

    2014-01-01

    Full Text Available Objective: The anti-microbial efficacy of 2.5% sodium hypochlorite (SHC and 0.2% chlorhexidine gluconate were compared with an experimental irrigant formulated from the Neem tree, Azadirachta indica A. Juss. Materials and Methods: A sample of 36 single rooted anterior teeth with periapical radiolucency and absence of response to vitality tests that required root canal treatment were selected for this study. The test irrigants and their combinations were assigned to five different groups and saline served as the control. Access cavities were prepared using an aseptic technique and samples collected for both anaerobic culture and Gram stained smears, followed by irrigation and sample collection again. The number of organisms were expressed in colony forming units/ml after 72 h of incubation; the smears were analyzed for their microbial loads and tissue clearance and assessed as per defined criteria. Results: Our results found the maximum reduction in microbial loads, when analyzed by culture method, with a combination of SHC and the experimental neem irrigant. Maximum tissue clearance on the Gram Stained smears was also found with the same combination. Conclusion: Neem irrigant has anti-microbial efficacy and can be considered for endodontic use.

  19. EFFECT OF GROUNDWATER TABLE CONTROL ON WATER SAVING IRRIGATION STRATEGIES IN THE QINGTONGXIA IRRIGATION DISTRICT

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-gui; HOLLANDERS P. H. J.

    2004-01-01

    This paper focuses on the analysis of the effects of groundwater table control under different irrigation water amounts on the water and salinity balance and on crop yield. Two experimental areas, the Pingluo and Huinong experimental sites, were selected to collect the required data.The agro-hydrological model Soil-Water Atmosphere-Plant(SWAP) was used to analyse the water flows and salt transport processes for different groundwater levels and irrigation scenarios. Six scenarios, which resulted from different groundwater table regimes combined with different irrigation amounts, were simulated. The results show that high groundwater tables due to the excessive irrigation are the main cause of the large amount of drainage water and low crop yield;reducing irrigation water without a lower groundwater table will not lead to a large reduction of the drainage water, and will reduce the crop yield even more; to lower the groundwater table is a good measure to control the drainage water and increase crop yield.

  20. Solar Energy Based Automated Irrigation System

    Directory of Open Access Journals (Sweden)

    Prof. Lodhi A. K.

    2013-09-01

    Full Text Available In the field of agriculture, use of proper method of irrigation is important because the main reason is the lack of rains {&} scarcity of land reservoir water. The continuous extraction of water from earth is reducing the water level due to which lot of land is coming slowly in the zones of un-irrigated land. Another very important reason of this is due to unplanned use of water due to which a significant amount of water goes waste. For this purpose; we use this automatic plant irrigation system. In this project we use solar energy which is used to operate the irrigation pump. The circuit comprises of sensor parts built using op-amp IC LM358. Op-amp are configured here as a comparator. Two stiff copper wires are inserted in the soil to sense whether the soil is wet or dry. The Microcontroller is used to control the whole system by monitoring the sensors and when sensors sense the dry condition then the microcontroller will send command to relay driver IC the contacts of which are used to switch on the motor and it will switch off the motor when all the sensors are in wet condition. The microcontroller does the above job as it receives the signal from the sensors through the output of the comparator, and these signals operate under the control of software which is stored in ROM of the Microcontroller. The condition of the pump i.e., ON/OFF is displayed on a 16X2 LCD

  1. Phosphorus losses in furrow irrigation runoff.

    Science.gov (United States)

    Westermann, D T; Bjorneberg, D L; Aase, J K; Robbins, C W

    2001-01-01

    Phosphorus (P) often limits the eutrophication of streams, rivers, and lakes receiving surface runoff. We evaluated the relationships among selected soil P availability indices and runoff P fractions where manure, whey, or commercial fertilizer applications had previously established a range of soil P availabilities on a Portneuf silt loam (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) surface-irrigated with Snake River water. Water-soluble P, Olsen P (inorganic and organic P), and iron-oxide impregnated paper-extractable P (FeO-Ps) were determined on a 0.03-m soil sample taken from the bottom of each furrow before each irrigation in fall 1998 and spring 1999. Dissolved reactive phosphorus (DRP) in a 0.45-microm filtered runoff sample, and iron-oxide impregnated paper-extractable P (FeO-Pw), total P, and sediment in an unfiltered runoff sample were determined at selected intervals during a 4-h irrigation on 18.3-m field plots. The 1998 and 1999 data sets were combined because there were no significant differences. Flow-weighted average runoff DRP and FeO-Pw concentrations increased linearly as all three soil P test concentrations increased. The average runoff total P concentration was not related to any soil P test but was linearly related to sediment concentration. Stepwise regression selected the independent variables of sediment, soil lime concentration, and soil organic P extracted by the Olsen method as related to average runoff total P concentration. The average runoff total P concentration was 1.08 mg L(-1) at a soil Olsen P concentration of 10 mg kg(-1). Soil erosion control will be necessary to reduce P losses in surface irrigation runoff.

  2. 静压箱式错流生物滴滤床去除甲苯废气的研究%Purification of toluene contained waste gas by static pressure tank cross-flow bio-trickling filter

    Institute of Scientific and Technical Information of China (English)

    彭淑婧; 李坚; 刘佳; 刘春敬; 李超; 金毓峑

    2011-01-01

    根据静压箱原理设计静压箱式错流生物滴滤床,设置进气静压区进一步改善气流分布情况,气流进入后在圆柱形静压区内动压降低,气流均匀分布.以甲苯为目标污染物、陶粒为填料、恶臭假单胞菌为菌源进行实验,研究静压箱式错流生物滴滤床的挂膜启动情况及稳定运行阶段甲苯停留时间、进气浓度对甲苯去除率的影响,分析了运行后期填料层压力损失增大的原因,并提出解决办法.%The static pressure tank cross-flow bio-trickling filter was designed on the principle of static pressure tank. A static pressure area was designed near the inlet of filter to improve the airflow distribution uniformity. The dynamic pressure of gas dropped as it flowed into the static pressure area so the gas was even distributed in filter. The waste gas purification by static pressure tank cross-flow bio-trickling filter was performed with toluene as target pollutant, ceramsite as packing material and Pseudomonas putida as degrading bacteria. The stat-up process of the bio-trickling filter was studied;the effects of inlet toluene concentration and residence time on removal capacity under stable operation stage were investigated; the reason of pressure drop rising in the filter was analyzed and the solutions were provided.

  3. Preliminary Study on Bio-trickling Filter Extracellular Polymeric Substances%关于生物滴滤塔内胞外聚合物的初步研究

    Institute of Scientific and Technical Information of China (English)

    张英; 杨榕; 张超; 党鹏刚

    2015-01-01

    为探究生物滴滤塔内EPS与生物量的关系,通过对氧化亚铁硫杆菌EPS提取方法进行对比,得出EDTA法EPS的提取效果最好;生物滴滤塔中活性炭表面生物量与T. f菌EPS有较大相关性,它的存在起到保护微生物、协助菌体吸附营养成分的作用;活性炭表面挂膜菌种后,其表面EPS主要为糖脂类、蛋白类物质,它们为微生物生长创造好的营养环境,能提高生物滴滤塔对SO2气体净化效果。%To explore the relationship between EPS of Bio-trickling Filter and biomass, by comparing extraction methods of extracellular polymeric substances of acidithiobacillus ferrooxidans, it was obtained that EDTA extraction method by EPS was best. The biomass of charcoal surface in the Biological trickling filter and the EPS of Acidithiobacillus ferrooxidans had greater relevance. It can protect microbes and help it to adsorb nutrients. EPS of charcoal surface was composed mainly by Glycolipids and Proteins. After biofilm bacteria in the surface of activated carbon, the EPS mainly was glycolipids and protein substances. It was a good environment for microbial growth nutrients. It can enhance the biological trickling filter purifying efficiency for SO2.

  4. Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

    Science.gov (United States)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2016-04-01

    The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

  5. Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

    NARCIS (Netherlands)

    Kissawike, K.

    2008-01-01

    This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to understand how irrigation and agricultural technologies have interacted with local society to transform production, paying particular attention to gender relations and changes for women farmers. The thesis seeks to

  6. Irrigation-based livelihood challenges and opportunities : a gendered technology of irrigation development intervention in the Lower Moshi irrigation scheme Tanzania

    NARCIS (Netherlands)

    Kissawike, K.

    2008-01-01

    This thesis is a study of a modernised irrigation scheme in Tanzania. It aims to understand how irrigation and agricultural technologies have interacted with local society to transform production, paying particular attention to gender relations and changes for women farmers. The thesis seeks to c

  7. Periodic Packing Mode for Trickle-Bed Reactors:Experiments and Modeling%滴流反应器的周期性填充:实验与模拟

    Institute of Scientific and Technical Information of China (English)

    刘国柱; 米镇涛

    2004-01-01

    A periodic packing mode of trickle-bed reactor(TBR)for the gas limited reaction was proposed.Hydrogenation of 2-ethylanthraquinone over Pd/Al2O3 in a laboratory-scale TBR was taken as a test reaction for determining whether the periodic packing mode is advantageous.The effects of operating conditions and packing type on TBR performance were experimentally examined to demonstrate the cause-effect relationships.A mathematic model of TBR considering axial dispersion and fractional wetting was developed to quantitatively illuminate the reason of performance enhancement.

  8. 基于人工神经网络的滴流床脉冲流频率的预测%Prediction of Pulsation Frequency of Pulsing Flow in Trickle Beds Based on Artificial Neural Network

    Institute of Scientific and Technical Information of China (English)

    刘国柱; 米镇涛

    2004-01-01

    An extensive database (946 measurements) for the frequency of pulsing flow in trickle beds was established by collecting the experimental results published over past 30 years. A new correlation based on artificial neural network (ANN) to predict the pulsation frequency was developed. Seven dimensionless numbers (groups)employed in the proposed correlation were liquid and gas Reynolds, liquid Weber, liquid Eotvos, gas Froude, and gas Stokes numbers and a bed correction factor. The comparisons of performance reported in the of literature and present correlations show that ANN correlation is a significant improvement in predicting pulsation frequency with an average absolute relative error (AARE) of 10% and a standard deviation less than 18%.

  9. Anthelmintic effect of carob pods and sainfoin hay when fed to lambs after experimental trickle infections with Haemonchus contortus and Trichostrongylus colubriformis

    Directory of Open Access Journals (Sweden)

    Arroyo-Lopez Celia

    2014-01-01

    Full Text Available The aim of the study was to compare the in vivo anthelmintic activity of sainfoin hay (Onobrychis viciifolia and carob pod meal (Ceratonia siliqua against gastrointestinal nematodes. Seven days before infection, 64 naive lambs were assigned to four different groups: Group S received sainfoin hay and group CAR was fed with carob pods. The remaining lambs received lucerne hay (Medicago sativa and were assigned to positive (non-treated, NT and negative (treated, T control groups (treatment with albendazole. On day 0, lambs were artificially trickle infected for 6 weeks, with a mixture of infective larvae of Haemonchus contortus and Trichostrongylus colubriformis. Parasitological and pathophysiological parameters were measured repeatedly during the 2-month study. Compared to the NT group, decreases in egg excretion were observed in the CAR and S groups with significant differences only found for sainfoin (p < 0.05. At necropsy, group S showed decreases in the total worm numbers of both nematode species with significant differences for H. contortus. In contrast, no differences were noticed for the CAR group. Compared to the NT group, lower values for fecundity of female H. contortus were found in the S and CAR groups, however differences were non-significant. No differences in body weight gains were found between groups. Consistent results were found showing significantly higher packed cell volume (PCV values in the T and S groups compared to NT and CAR groups. Overall, these results confirm a positive effect associated with the feeding of lambs with tanniniferous resources on host resilience (PCV values and against gastrointestinal parasitic nematodes by affecting some biological traits of worm populations (e.g. eggs per gram of faeces and worm numbers. However, the anthelmintic effects differed between the two tannin-containing resources, which might be associated with the quantity and/or quality of secondary metabolites (condensed tannins and

  10. Anthelmintic effect of carob pods and sainfoin hay when fed to lambs after experimental trickle infections with Haemonchus contortus and Trichostrongylus colubriformis.

    Science.gov (United States)

    Arroyo-Lopez, Celia; Manolaraki, Foteini; Saratsis, Anastasios; Saratsi, Katerina; Stefanakis, Alexandros; Skampardonis, Vasileios; Voutzourakis, Nikolaos; Hoste, Hervé; Sotiraki, Smaragda

    2014-01-01

    The aim of the study was to compare the in vivo anthelmintic activity of sainfoin hay (Onobrychis viciifolia) and carob pod meal (Ceratonia siliqua) against gastrointestinal nematodes. Seven days before infection, 64 naive lambs were assigned to four different groups: Group S received sainfoin hay and group CAR was fed with carob pods. The remaining lambs received lucerne hay (Medicago sativa) and were assigned to positive (non-treated, NT) and negative (treated, T) control groups (treatment with albendazole). On day 0, lambs were artificially trickle infected for 6 weeks, with a mixture of infective larvae of Haemonchus contortus and Trichostrongylus colubriformis. Parasitological and pathophysiological parameters were measured repeatedly during the 2-month study. Compared to the NT group, decreases in egg excretion were observed in the CAR and S groups with significant differences only found for sainfoin (p < 0.05). At necropsy, group S showed decreases in the total worm numbers of both nematode species with significant differences for H. contortus. In contrast, no differences were noticed for the CAR group. Compared to the NT group, lower values for fecundity of female H. contortus were found in the S and CAR groups, however differences were non-significant. No differences in body weight gains were found between groups. Consistent results were found showing significantly higher packed cell volume (PCV) values in the T and S groups compared to NT and CAR groups. Overall, these results confirm a positive effect associated with the feeding of lambs with tanniniferous resources on host resilience (PCV values) and against gastrointestinal parasitic nematodes by affecting some biological traits of worm populations (e.g. eggs per gram of faeces and worm numbers). However, the anthelmintic effects differed between the two tannin-containing resources, which might be associated with the quantity and/or quality of secondary metabolites (condensed tannins and/or other

  11. Cometabolic degradation of ethyl mercaptan by phenol-utilizing Ralstonia eutropha in suspended growth and gas-recycling trickle-bed reactor.

    Science.gov (United States)

    Sedighi, Mahsa; Zamir, Seyed Morteza; Vahabzadeh, Farzaneh

    2016-01-01

    The degradability of ethyl mercaptan (EM), by phenol-utilizing cells of Ralstonia eutropha, in both suspended and immobilized culture systems, was investigated in the present study. Free-cells experiments conducted at EM concentrations ranging from 1.25 to 14.42 mg/l, showed almost complete removal of EM at concentrations below 10.08 mg/l, which is much higher than the maximum biodegradable EM concentration obtained in experiments that did not utilize phenol as the primary substrate, i.e. 2.5 mg/l. The first-order kinetic rate constant (kSKS) for EM biodegradation by the phenol-utilizing cells (1.7 l/g biomass/h) was about 10 times higher than by cells without phenol utilization. Immobilized-cells experiments performed in a gas recycling trickle-bed reactor packed with kissiris particles at EM concentrations ranging from 1.6 to 36.9 mg/l, showed complete removal at all tested concentrations in a much shorter time, compared with free cells. The first-order kinetic rate constant (rmaxKs) for EM utilization was 0.04 l/h for the immobilized system compared to 0.06 for the suspended-growth culture, due to external mass transfer diffusion. Diffusion limitation was decreased by increasing the recycling-liquid flow rate from 25 to 65 ml/min. The removed EM was almost completely mineralized according to TOC and sulfate measurements. Shut down and starvation experiments revealed that the reactor could effectively handle the starving conditions and was reliable for full-scale application.

  12. Hydrodynamics of Three Biological Trickling Beds with Inert Filters%三种惰性填料生物滴滤床的流体力学性能

    Institute of Scientific and Technical Information of China (English)

    周超; 王芙蓉; 韩帅; 卢宏旭; 丁文明

    2016-01-01

    Using natural zeolite, expanded vermiculite and biological ceramsite as biological trickling bed fillers, in some running conditions such as dry and wet, spray amount, microbial growth, experiment of bed pressure drop vs gas flowrate data was carried out, and the pressure drop curve was obtained. Results showed that in various conditions biological ceramsite showed the best hydrodynamics performance. For the fragmented packing such as natural zeolite and expanded vermiculite, wetting can decrease the pressure drop loss, but spray volume would increase the pressure drop loss. Biofilm growth increased bed pressure drop loss, but for biological ceramsite packed bed the pressure drop increase was not significant.%对天然沸石、膨胀蛭石、生物陶粒等三种生物滴滤床惰性填料,进行了干燥与湿润、喷淋量、微生物生长等不同条件下,气体流量与床层压降数据测量,得到了影响条件下的压降曲线。结果分析显示,生物陶粒在各种条件下均表现出较好的流体力学性能;对天然沸石及膨胀蛭石类碎片状填料,润湿可减小压降损失,喷淋量过大会增大压降损失;生物膜生长增加生物滤床的压降损失,但对生物陶粒填料床,压降增加不显著。

  13. Effect of loading types on performance characteristics of a trickle-bed bioreactor and biofilter during styrene/acetone vapor biofiltration.

    Science.gov (United States)

    Halecky, Martin; Paca, Jan; Kozliak, Evguenii; Jones, Kim

    2016-07-02

    A 2:1 (w/w) mixture of styrene (STY) and acetone (AC) was subjected to lab-scale biofiltration under varied loading in both a trickle bed reactor (TBR) and biofilter (BF) to investigate substrate interactions and determine the limits of biofiltration efficiency of typical binary air pollutant mixtures containing both hydrophobic and polar components. A comparison of the STY/AC mixture degradation in the TBR and BF revealed higher pollutant removal efficiencies and degradation rates in the TBR, with the pollutant concentrations increasing up to the overloading limit. The maximum styrene degradation rates were 12 and 8 gc m(-3) h(-1) for the TBR and BF, respectively. However, the order of performance switched in favor of the BF when the loading was conducted by increasing air flow rate while keeping the inlet styrene concentration (Cin) constant in contrast to loading by increasing Cin. This switch may be due to a drastic difference in the effective surface area between these two reactors, so the biofilter becomes the reactor of choice when the rate-limiting step switches from biochemical processes to mass transfer by changing the loading mode. The presence of acetone in the mixture decreased the efficiency of styrene degradation and its degradation rate at high loadings. When the overloading was lifted by lowering the pollutant inlet concentrations, short-term back-stripping of both substrates in both reactors into the outlet air was observed, with a subsequent gradual recovery taking several hours and days in the BF and TBR, respectively. Removal of excess biomass from the TBR significantly improved the reactor performance. Identification of the cultivable strains, which was performed on Day 763 of continuous operation, showed the presence of 7 G(-) bacteria, 2 G(+) bacteria and 4 fungi. Flies and larvae of Lycoriella nigripes survived half a year of the biofilter operation by feeding on the biofilm resulting in the maintenance of a nearly constant pressure drop.

  14. Impacts of Irrigation on the Heat Fluxes and Near-Surface Temperature in an Inland Irrigation Area of Northern China

    Directory of Open Access Journals (Sweden)

    Li Jiang

    2014-03-01

    Full Text Available Irrigated agriculture has the potential to alter regional to global climate significantly. We investigate how irrigation will affect regional climate in the future in an inland irrigation area of northern China, focusing on its effects on heat fluxes and near-surface temperature. Using the Weather Research and Forecasting (WRF model, we compare simulations among three land cover scenarios: the control scenario (CON, the irrigation scenario (IRR, and the irrigated cropland expansion scenario (ICE. Our results show that the surface energy budgets and temperature are sensitive to changes in the extent and spatial pattern of irrigated land. Conversion to irrigated agriculture at the contemporary scale leads to an increase in annual mean latent heat fluxes of 12.10 W m−2, a decrease in annual mean sensible heat fluxes of 8.85 W m−2, and a decrease in annual mean temperature of 1.3 °C across the study region. Further expansion of irrigated land increases annual mean latent heat fluxes by 18.08 W m−2, decreases annual mean sensible heat fluxes by 12.31 W m−2, and decreases annual mean temperature by 1.7 °C. Our simulated effects of irrigation show that changes in land use management such as irrigation can be an important component of climate change and need to be considered together with greenhouse forcing in climate change assessments.

  15. Apical Extrusion of Irrigants in Immature Permanent Teeth by Using EndoVac and Needle Irrigation: An In Vitro Study.

    Directory of Open Access Journals (Sweden)

    N Velmurugan

    2014-08-01

    Full Text Available Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation.Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20: EndoVac Microcannula (group I, EndoVac Macrocannula (group II, NaviTip irrigation needle (group III and Max-i-Probe Irrigating needle (group IV; 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically.Group I, group III and group IV showed 100% extrusion (20/20 but group II showed only 40% extrusion (8/20. The difference in this respect between group II and other groups was statistically significant (P<0.001. With regards to the volume of extrusion, group II had only 0.23 ml of extruded irrigant. Group I extruded 7.53ml of the irrigant. Group III and group IV extruded the entire volume of irrigant delivered.EndoVac Macrocannula resulted in the least extrusion of irrigant in immature teeth when compared to EndoVac Microcannula and conventional needle irrigation.

  16. Where Does the Irrigation Water Go? An Estimate of the Contribution of Irrigation to Precipitation Using MERRA

    Science.gov (United States)

    Wei, Jiangfeng; Dirmeyer, Paul A.; Wisser, Dominik; Bosilovich, Michael G.; Mocko, David M.

    2013-01-01

    Irrigation is an important human activity that may impact local and regional climate, but current climate model simulations and data assimilation systems generally do not explicitly include it. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) shows more irrigation signal in surface evapotranspiration (ET) than the Modern-Era Retrospective Analysis for Research and Applications (MERRA) because ERA-Interim adjusts soil moisture according to the observed surface temperature and humidity while MERRA has no explicit consideration of irrigation at the surface. But, when compared with the results from a hydrological model with detailed considerations of agriculture, the ET from both reanalyses show large deficiencies in capturing the impact of irrigation. Here, a back-trajectory method is used to estimate the contribution of irrigation to precipitation over local and surrounding regions, using MERRA with observation-based corrections and added irrigation-caused ET increase from the hydrological model. Results show substantial contributions of irrigation to precipitation over heavily irrigated regions in Asia, but the precipitation increase is much less than the ET increase over most areas, indicating that irrigation could lead to water deficits over these regions. For the same increase in ET, precipitation increases are larger over wetter areas where convection is more easily triggered, but the percentage increase in precipitation is similar for different areas. There are substantial regional differences in the patterns of irrigation impact, but, for all the studied regions, the highest percentage contribution to precipitation is over local land.

  17. Traditional Irrigation Management in Betmera-Hiwane, Ethiopia: The Main Peculiarities for the Persistence of Irrigation Practices

    Institute of Scientific and Technical Information of China (English)

    Solomon Habtu; Kitamura Yoshinobu

    2006-01-01

    Traditional irrigation, as part of the ancient agricultural practices in northern Ethiopia (Tigray), has persisted for long time since 500 B.C.,while many newly introduced irrigation projects have usually failed there. The main objective of this study is thus to investigate the peculiarities pertinent to irrigation management and those having contributed for the persistence of traditional irrigation practices for a long period of time. The experience gained from such areas can definitely help make irrigation management system of new irrigation schemes sustainable. Betmera-Hiwane, one of the ancient traditional irrigation areas in Tigray region, was selected for the field study. Direct observations through field visits accompanied by interviews to farmers, local officials, local knowledgeable individuals and higher officials were made. After analyzing the collected primary and secondary information, the main peculiarities that contributed to the persistence of traditional irrigation areas were identified, and they are: the presence of communally constructed local rules, locally designed hydraulic control structures, ownership feeling of the irrigators and accountability of water distributors to the irrigation management, the culture for mobilizing communal resources and the culture of self-initiating local water management strategies.

  18. Energy performance of sprinkler irrigated maize, wheat and sunflower in Vigia irrigation district

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Sandra; Rodrigues, Goncalo Caleia; Paredes, Paula; Pereira, Luis S. [Centro de Engenharia dos Biossistemas (CEER/ISA), Lisboa (Portugal)], E-mail: lspereira@isa.utl.pt

    2008-07-01

    The energy potential of a crop may be evaluated through life cycle assessment methodologies. These refer to the computation of the crop's energy balance and other related indicators, such as the energy ratio and the energetic efficiency, that may be used as to assess how a given irrigated crop may be used for production of biofuel. This study concerns sprinkler irrigated sunflower, wheat and maize crops using data relative to the campaign of 2007 in the Vigia Irrigation District, Alentejo. A model was developed and various scenarios were considered. The modelling results lead to the conclusion that the maize crop is the most efficient in producing energy and sunflower is the least one for all the alternative scenarios considered. (author)

  19. Reservoir storage and irrigation in Arequipa, Peru

    Science.gov (United States)

    Ertsen, Maurits; Swiech, Theoclea; Machicao Pererya, Carlos

    2010-05-01

    In countries such as Peru, irrigated agriculture is not only vital for the subsistence of many but can also be a factor of economic development and by extent social improvement. To answer the local demand and respond to the water scarcity in the sub-basin of Yarabamba, near city of Arequipa, the government decided the construction of a dam for irrigation. The irrigation systems are affected by the lack of water during the dry season for lack of storage and of water distribution between downstream and upstream sectors, among other issues. Water scarcity is the main issue in the basin, leading to poor yields and the inability of growing crops with a high commercial value. Rainfall is available only from November to April, the rest of the year being very dry. Furthermore, the lowest areas of Yarabamba, Sogay and Quequeña are disadvantaged compared to the highest area of Polobaya. By creating a large storage area to regulate the variations of water availability through the year, the dam would allow to at least palliate the lack of water in existing lands, and at best to extend agricultural lands. Farmers would then be able to shift toward higher value crops more easily than without this extra storage. The main focus of the research was the dam which was supposed to improve the water distribution and availability in the sub-basin. From the results of the study, it can be concluded that other factors, related to the irrigation system itself, are involved in the efficiency of the new structure. The farmers, the main stakeholders, believe that more could be done to improve the system and their standard of living. Most of all, the main issue that should be resolved is the fair distribution of water. However, this is not possible without a strong cooperation between sectors, and a potential change in diversion structures. The competition between the districts should be reduced, otherwise the benefits of the dam would not give the expected results. This example shows that

  20. WATER MANAGEMENT STRATEGIES UNDER DEFICIT IRRIGATION

    Directory of Open Access Journals (Sweden)

    Antonino Capra

    2008-12-01

    Full Text Available Deficit irrigation (DI is an optimization strategy whereby net returns are maximized by reducing the amount of irrigation water; crops are deliberated allowed to sustain some degree of water deficit and yield reduction. Although the DI strategy dates back to the 1970s, this technique is not usually adopted as a practical alternative to full irrigation by either academics or practitioners. Furthermore, there is a certain amount of confusion regarding its concept. In fact, a review of recent literature dealing with DI has shown that only a few papers use the concept of DI in its complete sense (e.g. both the agronomic and economic aspects. A number of papers only deal with the physiological and agronomical aspects of DI or concern techniques such as Regulated Deficit Irrigation (RDI and Partial Root Drying (PRD. The paper includes two main parts: i a review of the principal water management strategies under deficit conditions (e.g. conventional DI, RDI and PRD; and ii a description of a recent experimental research conducted by the authors in Sicily (Italy that integrates agronomic, engineering and economic aspects of DI at farm level. Most of the literature reviewed here showed, in general, quite positive effects from DI application, mostly evidenced when the economics of DI is included in the research approach. With regard to the agronomic effects, total fresh mass and total production is generally reduced under DI, whereas the effects on dry matter and product quality are positive, mainly in crops for which excessive soil water availability can cause significant reductions in fruit size, colour or composition (grapes, tomatoes, mangos, etc.. The experimental trial on a lettuce crop in Sicily, during 2005 and 2006, shows that the highest mean marketable yield of lettuce (55.3 t ha-1 in 2005 and 51.9 t ha-1 in 2006 was recorded in plots which received 100% of ET0-PM (reference evapotranspiration by the Penman- Monteith method applied water. In

  1. Irrigation and avifaunal change in coastal Northwest Mexico: has irrigated habit attracted threatened migratory species?

    Directory of Open Access Journals (Sweden)

    Sievert Rohwer

    2015-08-01

    Full Text Available Irrigation in desert ecosystems can either reduce or increase species diversity. Groundwater pumping often lowers water tables and reduces natural wetlands, whereas canal irrigation often creates mesic habitat, resulting in great increases in avian diversity from irrigation. Here we compare a dataset of potential natural vegetation to recent datasets from areal and satellite imagery to show that 60% of the land in the coastal plain of southern Sonora and northern Sinaloa lying below 200 m elevation has been converted by irrigation to more mesic habitats. We then use the record of bird specimens in the world’s museums from this same region of Mexico to examine the avian community before and after the development of extensive irrigation. In general these museum records show an increase in the abundance and diversity of breeding birds associated with mesic habitats. Although thorn forest birds have likely decreased in total numbers, most are common enough in the remaining thorn forest that collection records did not indicate their probable decline. Four migrants having most of their breeding ranges in the US or Canada, Yellow-billed Cuckoo, Cliff Swallow, Bell’s Vireo, and Orchard Oriole, apparently have increased dramatically as breeders in irrigated habitats of NW Mexico. Because these species have decreased or even largely disappeared as breeding birds in parts of the US or Canada, further research should assess whether their increases in new mesic habitats of NW Mexico are linked to their declines as breeding birds in Canada and the US For Bell’s Vireo recent specimens from Sinaloa suggest its new breeding population in NW Mexico may be composed partly of the endangered Least Bell’s Vireo.

  2. Improvement of sustainability of irrigation in olive by the accurate management of regulated deficit irrigation

    Science.gov (United States)

    Memmi, Houssem; Moreno, Marta M.; Gijón, M. Carmen; Pérez-López, David

    2015-04-01

    Regulated Deficit Irrigation (RDI) is a useful tool to balance the improvement of productivity and water saving. This methodology is based in keeping the maximum yield with deficit irrigation. The key consists in setting water deficit during a non-sensitive phenological period. In olive, this phenological period is pit hardening, although, the accurate delimitation of the end of this period is nowadays under researching. Another interesting point in this methodology is how deep can be the water stress during the non-sensitive period. In this assay, three treatments were used in 2012 and 2013. A control treatment (T0), irrigated following FAO methodology, without water stress during the whole season and two RDI treatments in which water stress was avoided only during stage I and III of fruit growth. During stage II, widely considered as pit hardening, irrigation was ceased until trees reach the stated water stress threshold. Water status was monitored by means of stem water potential (ψs) measurements. When ψs value reached -2 MPa in T1 treatment, trees were irrigated but with a low amount of water with the aim of keeping this water status for the whole stage II. The same methodology was used for T2 treatment, but with a threshold of -3 MPa. Water status was also controlled by leaf conductance measurements. Fruit size and yield were determined at the end of each season. The statistically design was a randomized complete blocks with four repetitions. The irrigation amount in T1 and T2 was 50% and 65% less than T0 at the end of the study. There were no significant differences among treatments in terms of yield in 2012 (year off) and 2013 (year on).

  3. Optimizing preplant irrigation for maize under limited water in the high plains

    Science.gov (United States)

    Due to inadequate irrigation capacity, some farmers in the United States High Plains apply preplant irrigation to buffer the crop between irrigation events during the cropping season. The purpose of the study was to determine preplant irrigation amount and irrigation capacity combinations that optim...

  4. 25 CFR 171.415 - Can I place an obstruction on a BIA irrigation project?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I place an obstruction on a BIA irrigation project... IRRIGATION OPERATION AND MAINTENANCE Irrigation Facilities § 171.415 Can I place an obstruction on a BIA irrigation project? No. You may not place obstructions on BIA irrigation projects. (a) If you do so, we will...

  5. In vitro disinfection of dentinal tubules by various endodontics irrigants.

    Science.gov (United States)

    Buck, R; Eleazer, P D; Staat, R H

    1999-12-01

    Effectiveness of endodontic irrigants within dentinal tubules of human teeth was evaluated. Mid-sections of single-rooted teeth were prepared into dentin wedges. The pulpal sides of the sections were exposed to Micrococcus luteus or Bacillus megaterium that grew into the tubules. Irrigants used in the study included: 0.525% NaOCl, 0.12% chlorhexidine, RC Prep, 0.5% betadine iodine, and sterile H2O (as a control). Pulpal surfaces were exposed to an irrigant and then rinsed in sterile water. The samples were then cracked, exposing a fresh surface. Culture of the exposed dentin surfaces showed that selected irrigants reached to the far ends of the dentinal tubules in a concentration sufficient to kill 100% of the M. luteus. However B. megaterium was neither killed nor apparently inhibited by any irrigant. We conclude that endodontic irrigants permeate throughout dentinal tubules, but their effectiveness is dependent on the type of bacteria found within the tubules.

  6. Comparison of Manual and Automatic Irrigation of Pot Experiments

    DEFF Research Database (Denmark)

    Haahr, Vagner

    1975-01-01

    An air-lift principle for transport of water was adapted for automatic irrigation of experimental pots originally constructed for manual irrigation by the weighing method. The two irrigation techniques were compared in an experiment with increasing amounts of nitrogen fertilizer to spring barley....... Productions of grain and straw and chemical composition were almost the same after the two irrigation methods, and it was concluded that the laborious manual watering could be replaced by automatic irrigation. Comparison of the yield from individual plants in the pots showed a large difference between centre...... plants and border plants independent of irrigation principle. The increase in yield per pot with increasing N fertilization was at the highest N level caused only by an increase in yield of the border plants....

  7. Reform of irrigation management and investment policy in African development

    Directory of Open Access Journals (Sweden)

    KW Easter

    2015-01-01

    Full Text Available This paper examines the reform of water and irrigation management in Africa and compares it with similar reforms in Asia.  Several things are evident from the review.  First, Sub-Saharan Africa (SSA is at an earlier stage of irrigation development and reform than Asia.  Second, the articulated need for reform is much stronger in Asia than it is in SSA.  Third, the productivity of small-scale irrigated farms is significantly lower in SSA compared to Asia.  Thus any irrigation investment strategy in SSA should be different from Asia and focus on increasing small-farm productivity as well as small-scale irrigation projects.  Finally, all direct government irrigation investments should be done jointly with decisions regarding the type of project management.

  8. Irrigation Optimization by Modeling of Plant-Soil Interaction

    OpenAIRE

    2011-01-01

    Irrigation scheduling is an important issue for crop management, in a general context of limited water resources and increasing concern about agricultural productivity. Methods to optimize crop irrigation should take into account the impact of water stress on plant growth and the water balance in the plant-soil-atmosphere system. In this article, we propose a methodology to solve the irrigation scheduling problem. For this purpose, a plant-soil interaction model is used to simulate the struct...

  9. Water Supply Planning for Landscape Irrigation in Virginia

    OpenAIRE

    Tucker, Adrienne Janel LaBranche

    2009-01-01

    A water supply plan approach was used to investigate irrigation application on landscaped areas in Virginia with a focus on turfgrass. The economically-important turfgrass industry in Virginia should be proactive in conserving drinking water supplies to meet human consumption needs, especially in drought times. This thesis investigates current irrigation water supplies, water supply sustainability, and alternative water sources to meet irrigation demands and offers an insight on how potable w...

  10. 75 FR 29577 - Rate Adjustments for Indian Irrigation Projects

    Science.gov (United States)

    2010-05-26

    ... acre 68.00 70.00 Wapato Irrigation Project--Additional Works Minimum Charge per tract...... 63.00 65.00... Others Basic-per acre 20.50 22.50 (includes Bighorn, Soap Creek, and Pryor Units) *. Crow Irrigation Two... 86.00 feet (Ranch 5). San Carlos Irrigation Project (Joint Works) Basic per acre 21.00 21.00 (See...

  11. MANAGEMENT OF IRRIGATION AND NITROGEN FERTILIZERS TO REDUCE AMMONIA VOLATILIZATION

    Directory of Open Access Journals (Sweden)

    Fernando Viero

    2015-12-01

    Full Text Available ABSTRACT Nitrogen losses by ammonia (NH3 volatilization can be reduced by appropriate irrigation management or by alternative N sources, replacing urea. The objective of this study was to evaluate the efficiency of irrigation management and N source combinations in decreasing NH3 volatilization from an Argissolo Vermelho Distrófico típico cultivated for 28 years with black oat (Avena strigosa and maize (Zea mays, under no-tillage in the region of Depressão Central, Rio Grande do Sul, Brazil. The experiment was arranged in a randomized block design with split plots with three replications, where the main plots consisted of irrigation systems: no irrigation; irrigation immediately before and irrigation immediately after fertilization. The subplots were treated with different N sources: urea, urea with urease inhibitor and slow-release fertilizer, at an N rate of 180 kg ha-1, broadcast over maize, plus a control treatment without N fertilization. Ammonia volatilization was assessed using semi-open static collectors for 1, 2, 4, 6, and 10 days after N fertilization. In general, more than 90 % of total NH3-N losses occurred until three days after N fertilization, with peaks up to 15.4 kg ha-1 d-1. The irrigation was efficient to reduce NH3 losses only when applied after N fertilization. However, reductions varied according to the N fertilizer, and were higher for urea (67 % and slightly lower for urea with urease inhibitor (50 % and slow-release fertilizer (40 %, compared with the mean of the treatments without irrigation and irrigation before fertilization. The use of urea with urease inhibitor instead of urea was only promising under volatilization-favorable conditions (no irrigation or irrigation before N fertilization. Compared to urea, slow-release fertilizer did not reduce ammonia volatilization in any of the rainfed or irrigated treatments.

  12. Evaluation of Wetland Hydrology in Formerly Irrigated Areas

    Science.gov (United States)

    2017-07-01

    ER D C/ EL T R- 17 -1 3 Wetlands Regulatory Assistance Program Evaluation of Wetland Hydrology in Formerly Irrigated Areas En vi ro nm...EL TR-17-13 July 2017 Evaluation of Wetland Hydrology in Formerly Irrigated Areas Jacob F. Berkowitz, Jason P. Pietroski, and Steven J. Currie...of hydrology , and the distribution of plant communities. As a result, the identification of wetlands in irrigated areas remains challenging. The

  13. Influence of Irrigation Scheduling Using Thermometry on Peach Tree Water Status and Yield under Different Irrigation Systems

    Directory of Open Access Journals (Sweden)

    Huihui Zhang

    2017-02-01

    Full Text Available Remotely-sensed canopy temperature from infrared thermometer (IRT sensors has long been shown to be effective for detecting plant water stress. A field study was conducted to investigate peach tree responses to deficit irrigation which was controlled using canopy to air temperature difference (ΔT during the postharvest period at the USDA-ARS (U.S. Department of Agriculture, Agricultural Research Service San Joaquin Valley Agricultural Sciences Center in Parlier, California, USA. The experimental site consisted of a 1.6 ha early maturing peach tree orchard. A total of 18 IRT sensors were used to control six irrigation treatments including furrow, micro-spray, and surface drip irrigation systems with and without postharvest deficit irrigation. During the postharvest period in the 2012–2013 and 2013–2014 growing seasons, ΔT threshold values at mid-day was tested to trigger irrigation in three irrigation systems. The results showed that mid-day stem water potentials (ψ for well irrigated trees were maintained at a range of −0.5 to −1.2 MPa while ψ of deficit irrigated trees dropped to lower values. Soil water content in deficit surface drip irrigation treatment was higher compared to deficit furrow and micro-spray irrigation treatments in 2012. The number of fruits and fruit weight from peach trees under postharvest deficit irrigation treatment were less than those well-watered trees; however, no statistically significant (at the p < 0.05 level reduction in fruit size or quality was found for trees irrigated by surface drip and micro-spray irrigation systems by deficit irrigation. Beside doubles, we found an increased number of fruits with deep sutures and dimples which may be a long-term (seven-year postharvest regulated deficit irrigation impact of deficit irrigation on this peach tree variety. Overall, deployment of IRT sensors provided real-time measurement of canopy water status and the information is valuable for making irrigation

  14. Filtration, Treatment, and Maintenance Considerations for Micro-Irrigation Systems

    OpenAIRE

    Benham, Brian Leslie, 1960-; Ross, B. Blake

    2009-01-01

    Causes and Prevention of Emitter Plugging, Water Quality Analysis, Physical plugging hazards, Biological plugging hazards, Chemical plugging hazards, Flushing, Injecting chemicals into Micro-irrigation system

  15. The relationship between irrigation water demand and drought in the Yellow River basin

    Science.gov (United States)

    Wang, Yu; Wang, Weihao; Peng, Shaoming; Jiang, Guiqin; Wu, Jian

    2016-10-01

    In order to organize water for drought resistance reasonably, we need to study the relationship between irrigation water demand and meteorological drought in quantitative way. We chose five typical irrigation districts including the Qingtongxia irrigation district, Yellow River irrigation districts of Inner Mongolia in the upper reaches of the Yellow River, the Fen river irrigation district and the Wei river irrigation district in the middle reaches of the Yellow River and the irrigation districts in the lower reaches of the Yellow River as research area. Based on the hydrology, meteorology, groundwater and crop parameters materials from 1956 to 2010 in the Yellow River basin, we selected reconnaissance drought index (RDI) to analyze occurrence and evolution regularity of drought in the five typical irrigation districts, and calculated the corresponding irrigation water demand by using crop water balance equation. The relationship of drought and irrigation water demand in each typical irrigation district was studied by using grey correlation analysis and relevant analysis method, and the quantitative relationship between irrigation water demand and RDI was established in each typical irrigation district. The results showed that the RDI can be applied to evaluate the meteorological drought in the typical irrigation districts of the Yellow River basin. There is significant correlation between the irrigation water demand and RDI, and the grey correlation degree and correlation coefficient increased with increasing crops available effective rainfall. The irrigation water demand of irrigation districts in the upstream, middle and downstream of the Yellow River basin presented different response degrees to drought. The irrigation water demand increased 105 million m3 with the drought increasing one grade (RDI decreasing 0.5) in the Qingtongxia irrigation district and Yellow River irrigation districts of Inner Mongolia. The irrigation water demand increased 219 million m3

  16. Scale Effects in Laboratory and Pilot-Plant Reactors for Trickle-Flow Processes Les conséquences de l'extrapolation appliquée aux procédés à écoulement ruisselant réalisés en laboratoire et dans les réacteurs des unités-pilotes

    Directory of Open Access Journals (Sweden)

    Sie S. T.

    2006-11-01

    Full Text Available Research and development studies in a laboratory are necessarily conducted on a scale which is orders of magnitude smaller than that in commercial practice. In the case of the development and commercialization of an unprecedented novel process technology, available laboratory results have to be translated into envisaged technology on a commercial scale, i. e. the problem is that of scaling-up. However, in many circumstances the commercial technology is more or less defined as far as type of reactor is concerned and laboratory studies are concerned with the generation of predictive information on the behaviour of new catalysts, alternative feedstocks, etc. , in such a reactor. In many cases the complexity of feed composition and reaction kinetics preclude the prediction to be made on the basis of a combination of fundamental kinetic data and computer models, so that there is no other option than to simulate the commercial reactor on a laboratory scale, i. e. the problem is that of scaling-down. From the point of view of R & D Defficiency, the scale of the laboratory experiments should be as small as possible without detracting from the meaningfulness of the results. In the present paper some problems in the scaling-down of a trickle-flow reactor as applied in hydrotreating processes to kinetically equivalent laboratory reactors of different sizes will be discussed. Two main aspects relating to inequalities in fluid dynamics resulting from the differences in scale will be treated in more detail, viz. deviations from ideal plug flow and non ideal wetting or irrigation of the catalyst particles. Although a laboratory reactor can never be a true small-scale replica of a commercial trickle-flow reactor in all respects, it can nevertheless be made to provide representative data as far as the catalytic conversion aspects are concerned. By ressorting to measures such as catalyst bed dilution with fine catalytically inert material it proves possible to

  17. Apical Extrusion of Irrigants in Immature Permanent Teeth by Using EndoVac and Needle Irrigation: An In Vitro Study

    Science.gov (United States)

    Velmurugan, N; Sooriaprakas, C; Jain, Preetham

    2014-01-01

    Objective: Immature teeth have a large apical opening and thin divergent or parallel dentinal walls; hence, with conventional needle irrigation there is a very high possibility of extrusion. This study was done to compare the apical extrusion of NaOCl in an immature root delivered using EndoVac and needle irrigation. Materials and Methods: Eighty freshly extracted maxillary central incisors were decoronated followed by access cavity preparation. Modified organotypic protocol was performed to create an open apex; then, the samples were divided into four groups (n=20): EndoVac Microcannula (group I), EndoVac Macrocannula (group II), NaviTip irrigation needle (group III) and Max-i-Probe Irrigating needle (group IV); 9.0 ml of 3% sodium hypochlorite was delivered slowly over a period of 60 seconds. Extruded irrigants were collected in a vial and analysed statistically. Results: Group I, group III and group IV showed 100% extrusion (20/20) but group II showed only 40% extrusion (8/20). The difference in this respect between group II and other groups was statistically significant (Pirrigant. Group I extruded 7.53ml of the irrigant. Group III and group IV extruded the entire volume of irrigant delivered. Conclusion: EndoVac Macrocannula resulted in the least extrusion of irrigant in immature teeth when compared to EndoVac Microcannula and conventional needle irrigation. PMID:25584055

  18. Comparison of irrigant penetration up to working length and into simulated lateral canals using various irrigating techniques.

    Science.gov (United States)

    Spoorthy, E; Velmurugan, N; Ballal, S; Nandini, S

    2013-09-01

    To evaluate the effect of an apical negative pressure system, a passive ultrasonic irrigation system and a combination of both apical negative pressure and passive ultrasonic irrigation on the penetration of the irrigating contrast solution (ICS) up to working length and into simulated lateral canals. The root canals of 64 single-rooted teeth were instrumented using the ProTaper rotary system. In each sample, three simulated lateral canals were created at 2, 4 and 6 mm levels from the root apex using a 06-size C+ file (Dentsply Maillefer, Ballaigues, Switzerland). Samples were randomly assigned into 4 experimental groups (n = 16): group I - conventional needle irrigation, group II - passive ultrasonic irrigation, group III - apical negative irrigation system and group IV - combination of passive ultrasonic irrigation and apical negative pressure irrigation system. To examine irrigating solution penetration, Indian ink was mixed with 5.25% NaOCl and delivered into the root canals. Samples were then assessed by direct observation of the images taken using Canon EOS rebel T3. The depth of penetration of ICS up to the working length and into the simulated lateral canals was analysed using chi-squared tests. The combination (ANP and PUI) and ANP group had significantly deeper ICS penetration up to the working length (P Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. Comparison of sealer penetration using the EndoVac irrigation system and conventional needle root canal irrigation.

    Science.gov (United States)

    Kara Tuncer, Aysun; Unal, Bayram

    2014-05-01

    The aim of this study was to compare the effect of the EndoVac irrigation system (SybronEndo, Orange, CA) and conventional endodontic needle irrigation on sealer penetration into dentinal tubules. Forty single-rooted, recently extracted human maxillary central incisors were randomly divided into 2 groups according to the irrigation technique used: conventional endodontic needle irrigation and EndoVac irrigation. All teeth were instrumented using the ProFile rotary system (Dentsply Maillefer, Ballaigues, Switzerland) and obturated with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) labeled with fluorescent dye. Transverse sections at 1, 3, and 5 mm from the root apex were examined using confocal laser scanning microscopy. The total percentage and maximum depth of sealer penetration were then measured. Mann-Whitney test results showed that EndoVac irrigation resulted in a significantly higher percentage of sealer penetration than conventional irrigation at both the 1- and 3-mm levels (P irrigation system significantly improved the sealer penetration at the 1- to 3-mm level over that of conventional endodontic needle irrigation. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Appropriate designs and appropriating irrigation systems : irrigation infrastructure development and users' management capability in Bolivia

    NARCIS (Netherlands)

    Gutierrez Pérez, Z.

    2005-01-01

    The objectives of this book are to explore and demonstrate the 'divorce' that is taking place in how critical actors think about irrigation infrastructure design and management, and in how designers often impose their own narrow preferences in infrastructure composition and performance without refle

  1. Irrigation and fertigation with drip and alternative micro irrigation systems in northern highbush blueberry

    Science.gov (United States)

    The effects of nitrogen (N) fertigation using conventional drip and alternative micro irrigation systems were evaluated in six cultivars of northern highbush blueberry. The drip system consisted of two laterals of drip tubing, with 2 L/h in-line emitters (point source) spaced every 0.45 m, on each s...

  2. Laser assisted irrigation and hand irrigation for root canal decontamination: a comparison

    Science.gov (United States)

    Olivi, M.; Stefanucci, M.; Todea, C.

    2014-01-01

    Aim: to compare the bactericidal efficiency of conventional method and LAI for root canal decontamination. Material and method: 22 human single root teeth, extracted for periodontal problems, mechanically prepared up to ISO 25 at the working lenght were divided in 2 groups: after sterilization, the teeth were infected with enterococcus faecalis and incubated for 4 weeks. Group A: 10 teeth were irrigated with conventional hand technique (CI): 3ml of 5% NaClO were used for two times of 30s each and after washing with sterile bi-distilled water for 20s, a final irrigation was performed with 3ml of 17% EDTA. Group B: 10 teeth were irrigated with 3ml of NaClO and activated by erbium laser, two cycles of 30s; also the final irrigation with 3ml of 17% EDTA was activated by erbium laser. In both the groups a resting time of 30s was used between the two sessions to allow the reaction rate of NaClO. The Erbium laser 2940 nm (LightWalker AT, Fotona; Lublijana, Slovenia) was used with 50microsecond pulse duration, at 15Hz, 20mJ, with a 600micron PIPS tip. Two samples were used as positive and negative control.

  3. Irrigating lives : Development intervention and dynamics of social relationships in an irrigation project

    NARCIS (Netherlands)

    Magadlela, D.

    2000-01-01

    This study is about rural agricultural development and social processes of change in rural Zimbabwe. It is aimed at understanding how irrigation intervention in a remote rural context changed the cultural, social, political and farming lives of people. It is a study of people coping with changes in

  4. Irrigating lives : development intervention and dynamics of social relationships in an irrigation project

    NARCIS (Netherlands)

    Magadlela, D.

    2000-01-01

    This study is about rural agricultural development and social processes of change in rural Zimbabwe. It is aimed at understanding how irrigation intervention in a remote rural context changed the cultural, social, political and farming lives of people. It is a study of people coping with ch

  5. Effects of Irrigation Practices on Some Soil Chemical Properties on OMI Irrigation Scheme

    Directory of Open Access Journals (Sweden)

    M.A. Adejumobi

    2014-10-01

    Full Text Available Irrigation practices have been observed to impact scheme soil properties and other parameters negatively. These could be as a result of irrigation water quality, method of application and nature of scheme soil. This study was therefore conducted to study the effects of irrigation practices on the soils of Omi irrigation scheme Kogi state, Nigeria after 13years of operation. Soil samples were taken at depths 0 – 20 cm (A1, 20 – 80 cm (A2 and 80 – 120 cm (A3 from two operating lands (OL; OL 5 and OL 18 of the study area. The samples were analysed for chemical parameters (pH, CEC, ESP, Mg2+, Ca2+, OM, and OC. The soil pH which was in the neutral range (pH=6.65 to 7.00 at inception of scheme, has become slightly acidic (pH=6.53 to 6.60. Cation exchange capacity (CEC levels have also increased from 10cmol+kg-1 to 35cmol+kg-1. While Organic matter (OM and Organic carbon (OC also have marked increase in their levels (baseline as 0.93 to 1.08; for year 2013 as 9.52 to 9.79. Generally, the analysis indicated a need for proper monitoring of the scheme soil to prevent further deterioration.

  6. Intervention Processes and Irrigation Institutions: Sustainability of Farmer Managed Irrigation Systems in Nepal

    NARCIS (Netherlands)

    Pant, D.R.

    2000-01-01

    With the support from various donors, His Majesty's Government of Nepal has implemented support programmes with a view to transform water availability, improve production, and increase the institutional capabilities of farmers to develop and sustain efficient, fair and reliable irrigation management

  7. 77 FR 21556 - Don Pedro Hydroelectric Project: Turlock Irrigation District; Modesto Irrigation District...

    Science.gov (United States)

    2012-04-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Don Pedro Hydroelectric Project: Turlock Irrigation District; Modesto... Tuolumne Habitats for Anadromous Fish; Request 8--Salmon and Steelhead Full Life-Cycle Population Models...

  8. 76 FR 58249 - Notice of Availability of Proposed Low Effect Habitat Conservation Plan for Tumalo Irrigation...

    Science.gov (United States)

    2011-09-20

    ... Effect Habitat Conservation Plan for Tumalo Irrigation District's Tumalo Conservation Project AGENCY... Tumalo Irrigation District's (TID) application for an incidental take permit, pursuant to the Endangered... Columbia River Steelhead in the Deschutes River basin that may occur from irrigation activities...

  9. 钯催化剂2-乙基蒽醌加氢滴流床反应器模拟%SIMULATION OF TRICKLE-BED REACTOR FOR HYDROGENATION OF 2-ETHYLANTHRAQUINONE WITH PALLADIUM CATALYST

    Institute of Scientific and Technical Information of China (English)

    吕树祥; 王莅; 刘建国; 陈四海; 王亚权; 米镇涛

    2003-01-01

    Hydrogenation of 2-ethylanthraquinone is a key step in the industrial production of hydrogen peroxide via anthraquinone. This reaction on palladium-supported catalysts is normally carried out in trickle-bed reactors. A numerical model for simulation of a gas-liquid-solid hydrogenation trickle-bed reactor is presented. The model is based on the film theory and takes into account the axial dispersion effect on the performance of the reactor. Comparison of calculated values with data from pilot plant and industrial reactor shows that the agreement is quite satisfactory and the maximum variance is less than 5%. Gas-liquid and liquid-solid mass-transfer coefficients are determined by semi-empirical correlations available in the literature. The palladium-supported catalyst is extremely active and the reaction is always controlled by gas-liquid mass-transfer, and the overall effectiveness factor is always very low in agreement with the high catalytic activity of the palladium-supported catalyst. The overall effectiveness factor increases with decreasing catalyst hold-up. Therefore, it is feasible to improve the productivity of unit catalyst by decreasing the catalyst hold-up in a commercial plant with the hydrodynamic characters kept unchange.

  10. Formalin irrigation for hemorrhagic chronic radiation proctitis.

    Science.gov (United States)

    Ma, Teng-Hui; Yuan, Zi-Xu; Zhong, Qing-Hua; Wang, Huai-Ming; Qin, Qi-Yuan; Chen, Xiao-Xia; Wang, Jian-Ping; Wang, Lei

    2015-03-28

    To assess the efficacy and safety of a modified topical formalin irrigation method in refractory hemorrhagic chronic radiation proctitis (CRP). Patients with CRP who did not respond to previous medical treatments and presented with grade II-III rectal bleeding according to the Common Terminology Criteria for Adverse Events were enrolled. Patients with anorectal strictures, deep ulcerations, and fistulas were excluded. All patients underwent flexible endoscopic evaluation before treatment. Patient demographics and clinical data, including primary tumor, radiotherapy and previous treatment options, were collected. Patients received topical 4% formalin irrigation in a clasp-knife position under spinal epidural anesthesia in the operating room. Remission of rectal bleeding and related complications were recorded. Defecation, remission of bleeding, and other symptoms were investigated at follow-up. Endoscopic findings in patients with rectovaginal fistulas were analyzed. Twenty-four patients (19 female, 5 male) with a mean age of 61.5 ± 9.5 years were enrolled. The mean time from the end of radiotherapy to the onset of bleeding was 11.1 ± 9.0 mo (range: 2-24 mo). Six patients (25.0%) were blood transfusion dependent. The median preoperative Vienna Rectoscopy Score (VRS) was 3 points. Nineteen patients (79.2%) received only one course of topical formalin irrigation, and five (20.8%) required a second course. No side effects were observed. One month after treatment, bleeding cessation was complete in five patients and obvious in 14; the effectiveness rate was 79.1% (19/24). For long-term efficacy, 5/16, 1/9 and 0/6 patients complained of persistent bleeding at 1, 2 and 5 years after treatment, respectively. Three rectovaginal fistulas were found at 1 mo, 3 mo and 2 years after treatment. Univariate analysis showed associations of higher endoscopic VRS and ulceration score with risk of developing rectovaginal fistula. Modified formalin irrigation is an effective and safe

  11. Irrigation and fertigation frequencies with nitrogen in the watermelon culture

    Directory of Open Access Journals (Sweden)

    Carlos Newdmar Vieira Fernandes

    2014-06-01

    Full Text Available This study evaluates the influence of different irrigation frequencies and different nitrogen fertigation frequencies on the growth performance of the watermelon (Citrullus lanatus culture. Two experiments were conducted at the Paraguay farm in the Cruz municipality, Ceará, Brazil. They was randomized blocks design with six treatments and four replications. The irrigation frequency experiment consisted of the application of different irrigation frequencies. The treatments were: DM - daily irrigation in the morning with 100% daily dosage; DT - daily irrigation in the afternoon, with 100% daily dosage; DMT - twice daily irrigation, with 50% daily dosage in the morning and 50% daily dosage in the afternoon; 2D - irrigation every two days; 3D - irrigation every three days and 4D - irrigation every four days. To the experiment with different nitrogen fertigation frequencies, the treatments used were: 2F - 2 fertigations in a cycle; 4F - 4 fertigations in a cycle; 8F - 8 fertigations in a cycle; 16F - 16 fertigations in a cycle; 32F - 32 fertigations in a cycle and 64F - 64 fertigations in a cycle. We evaluated the marketable yield (PC, fruit weight (M, polar diameter (DP, equatorial diameter (DE, shell thickness (EC and soluble solids (SS. The irrigation frequency treatments influenced all variables significantly, with twice daily irrigation (DMT, 50% in the morning and the 50% in the afternoon promoting the highest productivity (69.79 t ha-1. The different frequencies of fertigation also significantly influenced all variables, except for the shell thickness, the highest yield (80.69 t ha-1 being obtained with treatment 64 fertigations in a cycle.

  12. Derivation of irrigation requirements for radiological impact assessments.

    Science.gov (United States)

    Almahayni, Talal; Crout, Neil M J

    2016-11-01

    When assessing the radiological impacts of radioactive waste disposal, irrigation using groundwater contaminated with releases from the disposal system is a principal means of crop and soil contamination. In spite of their importance for radiological impact assessments, irrigation data are scarce and often associated with considerable uncertainty for several reasons including limited obligation to measure groundwater abstraction and differences in measuring methodologies. Further uncertainty arises from environmental (e.g. climate and landscape) change likely to occur during the assessment long time frame. In this paper, we derive irrigation data using the crop growth AquaCrop model relevant to a range of climates, soils and crops for use in radiological impact assessments. The AquaCrop estimates were compared with actual irrigation data reported in the literature and with estimates obtained from simple empirical methods proposed for use in radiological impact assessments. Further, the AquaCrop irrigation data were analysed using mixed effects modelling to investigate the effects of climate, soil and crop type on the irrigation requirement. Irrigation estimates from all models were within a reasonable range of the measured values. The AquaCrop estimates, however, were at the higher end of the range and higher than those from the empirical methods. Nevertheless, they may be more appropriate for conservative radiological assessments. The use of mixed effects modelling allowed for the characterisation of crop-specific variability in the irrigation data, and in contrast to the empirical methods, the AquaCrop and the mixed effects models accounted for the soil effect on the irrigation requirement. The approach presented in this paper is relevant for obtaining irrigation data for a specific site under different climatic conditions as well as for generic dose assessments. To the best of our knowledge, this is one of the most comprehensive analyses of irrigation data in

  13. Water savings potentials of irrigation systems: dynamic global simulation

    Science.gov (United States)

    Jägermeyr, J.; Gerten, D.; Heinke, J.; Schaphoff, S.; Kummu, M.; Lucht, W.

    2015-04-01

    Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatio-temporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of global agricultural water use, and of water saving and water productivity potentials constrained by biophysical processes and also non-trivial downstream effects, we incorporated a dynamic representation of the three major irrigation systems (surface, sprinkler, and drip) into a process-based bio- and agrosphere model, LPJmL. Based on this enhanced model we provide a gridded worldmap of dynamically retrieved irrigation efficiencies reflecting differences in system types, crop types, climatic and hydrologic conditions, and overall crop management. We find pronounced regional patterns in beneficial irrigation efficiency (a refined irrigation efficiency indicator accounting for crop-productive water consumption only), due to differences in these features, with lowest values (values (> 60%) in Europe and North America. We arrive at an estimate of global irrigation water withdrawal of 2396 km3 (2004-2009 average); irrigation water consumption is calculated to be 1212 km3, of which 511 km3 are non-beneficially consumed, i.e. lost through evaporation, interception, and conveyance. Replacing surface systems by sprinkler or drip systems could, on average across the world's river basins, reduce the non-beneficial consumption at river basin level by 54 and 76%, respectively, while maintaining the current level of crop yields. Accordingly, crop water productivity would increase by 9 and 15%, respectively, and by much more in specific regions such as in the Indus basin. This study significantly advances the global quantification of irrigation systems while providing a framework for assessing

  14. Effects of global irrigation on the near-surface climate

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, William J. [University of Wisconsin-Madison, Center for Sustainability and the Global Environment, Madison, WI (United States); Cook, Benjamin I. [Lamont-Doherty Earth Observatory, Ocean and Climate Physics, Palisades, NY (United States); NASA Goddard Institute for Space Studies, New York, NY (United States); Buenning, Nikolaus [University of Colorado-Boulder, Department of Atmospheric and Oceanic Sciences and Cooperative Institute for Research in Environmental Sciences, Boulder, CO (United States); Levis, Samuel [National Center for Atmospheric Research, Climate and Global Dynamics Division, Boulder, CO (United States); Helkowski, Joseph H. [Earth Tech, Miami, FL (United States)

    2009-08-15

    Irrigation delivers about 2,600 km{sup 3} of water to the land surface each year, or about 2% of annual precipitation over land. We investigated how this redistribution of water affects the global climate, focusing on its effects on near-surface temperatures. Using the Community Atmosphere Model (CAM) coupled to the Community Land Model (CLM), we compared global simulations with and without irrigation. To approximate actual irrigation amounts and locations as closely as possible, we used national-level census data of agricultural water withdrawals, disaggregated with maps of croplands, areas equipped for irrigation, and climatic water deficits. We further investigated the sensitivity of our results to the timing and spatial extent of irrigation. We found that irrigation alters climate significantly in some regions, but has a negligible effect on global-average near-surface temperatures. Irrigation cooled the northern mid-latitudes; the central and southeast United States, portions of southeast China and portions of southern and southeast Asia cooled by {proportional_to}0.5 K averaged over the year. Much of northern Canada, on the other hand, warmed by {proportional_to}1 K. The cooling effect of irrigation seemed to be dominated by indirect effects like an increase in cloud cover, rather than by direct evaporative cooling. The regional effects of irrigation were as large as those seen in previous studies of land cover change, showing that changes in land management can be as important as changes in land cover in terms of their climatic effects. Our results were sensitive to the area of irrigation, but were insensitive to the details of irrigation timing and delivery. (orig.)

  15. Berry morphology and composition in irrigated and non-irrigated grapevine (Vitis vinifera L.).

    Science.gov (United States)

    Sofo, Adriano; Nuzzo, Vitale; Tataranni, Giuseppe; Manfra, Michele; De Nisco, Mauro; Scopa, Antonio

    2012-07-15

    The present study was carried out in a 5-year-old vineyard (Vitis vinifera L., cv. Aglianico) located in Southern Italy. Half of the plants (IRR) were fully irrigated, whereas the other half were not irrigated (NIRR). In both of the treatments, plant water status, gas exchange, photosynthetic efficiency and productive performance were determined. The arid conditions resulted in significant decreases in stem water potential in NIRR (minimum values of -1.34 and -1.52 MPa in IRR and NIRR, respectively). The values of yield per plant, cluster weight and total berry weight were significantly higher in IRR. Grape berries were separated into four weight classes, and morphometric and microscopic analyses were carried out to measure and calculate berry skin characteristics. Irrigation determined a marked shift toward heavier (+23% in the class ≥ 1.25 g) and bigger (336.35 mm³ vs 299.15 mm³) berries, and induced significant changes in other morphometric berry parameters. No differences among berry weight classes and irrigation treatments were observed for berry skin thickness. In all of the berry weight classes, total anthocyanins extracted from berry skins were significantly higher in NIRR than in IRR (12301.53 and 9585.52 mg kg⁻¹ fresh berry skin, respectively), and appeared to be positively related to berry weight, whereas total flavonols were not significantly different between the two treatments. Qualitative changes in the levels of single anthocyanin and flavonol compounds were detected between IRR and NIRR. In addition, iron, copper and zinc, whose high concentration can negatively affect wine quality, were significantly higher in the IRR treatment. The results highlighted that the absence of irrigation did not determine decreases in grape quality. Such data can be of primary importance in environments where water availability is by far the most important limiting factor for plant growth.

  16. Distillation irrigation: a low-energy process for coupling water purification and drip irrigation

    Science.gov (United States)

    Constantz, J.

    1989-01-01

    A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply the distillate to a widely spaced row crop. To predict the performance of the proposed device, an empirical equation for distillate production, dp, is developed from reported solar still production rates, and a modified Jensen-Haise equation is used to calculate the potential evapotranspiration, et, for a row crop. Monthly values for et and dp are calculated by using a generalized row crop at five locations in the Western United States. Calculated et values range from 1 to 22 cm month-1 and calculated dp values range from 2 to 11 cm month-1, depending on the location, the month, and the crop average. When the sum of dp plus precipitation, dp + P, is compared to et for the case of 50% distillation irrigation system coverage, the results indicate that the crop's et is matched by dp + P, at the cooler locations only. However, when the system coverage is increased to 66%, the crop's et is matched by dp + P even at the hottest location. Potential advantages of distillation irrigation include the ability: (a) to convert impaired water resources to water containing no salts or sediments; and (b) to efficiently and automatically irrigate crops at a rate that is controlled primarily by radiation intensities. The anticipated disadvantages of distillation irrigation include: (a) the high costs of a system, due to the large amounts of sheeting required, the short lifetime of the sheeting, and the physically cumbersome nature of a system; (b) the need for a widely spaced crop to reduce shading of the system by the crop; and (c) the production of a concentrated brine or precipitate, requiring proper off-site disposal. ?? 1989.

  17. Winter Irrigation Effects in Cotton Fields in Arid Inland Irrigated Areas in the North of the Tarim Basin, China

    Directory of Open Access Journals (Sweden)

    Pengnian Yang

    2016-02-01

    Full Text Available Winter irrigation is one of the water and salt management practices widely adopted in arid irrigated areas in the Tarim Basin located in the Xinjiang Uygur Autonomous Region in the People’s Republic of China. A winter irrigation study was carried out from November 2013 to March 2014 in Korla City. A cotton field was divided into 18 plots with a size of 3 m × 3 m and five winter irrigation treatments (1200 m3/ha, 1800 m3/ha, 2400 m3/ha, 3000 m3/ha, and 3600 m3/ha and one non-irrigation as a control were designed. The results showed that the higher winter irrigation volumes allowed the significant short-term difference after the irrigation in the fields with the higher soil moisture content. Therefore, the soil moisture in the next sowing season could be maintained at the level which was slightly lower than field capacity and four times that in the non-irrigation treatment. The desalination effect of winter irrigation increased with the increase of water irrigation volume, but its efficiency decreased with the increase of water irrigation volume. The desalination effect was characterized by short-term desalination, long-term salt accumulation, and the time-dependent gradually decreasing trend. During the winter irrigation period, air temperature was the most important external influencing factor of the soil temperature. During the period of the decrease in winter temperatures from December to January, soil temperature in the 5-cm depth showed no significant difference in all the treatments and the control. However, during the period of rising temperatures from January to March, soil temperature in the control increased significantly, faster than that in all treatments. Under the same irrigation volume, the temperature difference between the upper soil layer and the lower soil layer increased during the temperature drop period and decreased during the temperature rise period. In this paper, we proposed the proper winter irrigation volume of 1800

  18. More efficient irrigation may compensate for increases in irrigation water requirements due to climate change in the Mediterranean area

    Science.gov (United States)

    Fader, Marianela; Shi, Sinan; von Bloh, Werner; Bondeau, Alberte; Cramer, Wolfgang

    2017-04-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. We will present a recently published study1 that estimates the current level of water demand for Mediterranean agriculture and simulates the potential impacts of climate change, population growth and transitions to water-saving irrigation and conveyance technologies. The results indicate that, at present, Mediterranean region could save 35% of water by implementing more efficient irrigation and conveyance systems, with large differences in the saving potentials across countries. Under climate change, more efficient irrigation is of vital importance for counteracting increases in irrigation water requirements. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4% and 18% from climate change alone by the end of the century if irrigation systems and conveyance are not improved. Population growth increases these numbers to 22% and 74%, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean. Both the Eastern and the Southern Mediterranean would need around 35% more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect. However, in some scenarios water scarcity may constrain the supply of the irrigation water needed in future in Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain. In this study, vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL ("Lund-Potsdam-Jena managed Land") after a large development2 that comprised the improved representation of Mediterranean crops.

  19. The effects of deifcit irrigation on nitrogen consumption, yield, and quality in drip irrigated grafted and ungrafted watermelon

    Institute of Scientific and Technical Information of China (English)

    Seluk zmen; Rza Kanber; Nebahat Sar; Mustafa nl

    2015-01-01

    The aim of this study is to determine the effects of deifcit irrigation on nitrogen consumption, yield, and quality in grafted and ungrafted watermelon. The study was conducted in Çukurova region, Eastern Mediterranean, Turkey, between 2006 and 2008, and employed 3 irrigation rates (ful irrigation (I100) with no stress, moderate irrigation (DI70), and low irrigation (DI50);DI70 and DI50 were considered deifcit irrigation) on grafted (CTJ, Crimson Tide+Jumbo) and the ungrafted (CT, Crim-son Tide) watermelon. The amount of irrigation water (IR) applied to the study plots were calculated based on cumulative pan evaporation that occurred during the irrigation intervals. Nitrogen consumption was 16%lower in CTJ plants than in CT plants. On the other hand, consumption of nitrogen was 28%higher in DI50 plants than in DI70 plants while it was 23%higher in DI50 plants than in I100 plants. By grafting, the average amount of nitrogen content in seeds, pulps and peels for CTJ was 30, 43 and 56%more than those of CT, respectively. The yield and the quality were not signiifcantly affected by the deifcit irrigation. In this respect, grafting of watermelon gave higher yield, but, it had a slight effect on fruit quality. The highest yield values of 16.90 and 19.32 kg plant–1 in 2008 were obtained with I100 and in CTJ plants, respectively. However, DI50 treatment could be taken into account for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited. Additional y, the yield increased by applying CTJ treatment to the watermelon production.

  20. Root Zone Sensors for Irrigation Management in Intensive Agriculture

    NARCIS (Netherlands)

    Pardossi, A.; Incrocci, L.; Incrocci, G.; Marlorgio, F.; Battista, P.; Bacci, L.; Rapi, B.; Marzialetti, P.; Hemming, J.; Balendonck, J.

    2009-01-01

    Crop irrigation uses more than 70% of the world’s water, and thus, improving irrigation efficiency is decisive to sustain the food demand from a fast-growing world population. This objective may be accomplished by cultivating more water-efficient crop species and/or through the application of effici

  1. Impact of drought genetics on irrigated corn production

    Science.gov (United States)

    Corn is the major irrigated crop in the High Plains of Colorado, Nebraska, and Kansas. Declining water levels in the High Plains Aquifer have reduced well capacity such that limited irrigation strategies must be employed. Crop breeding advances have led to the introduction of drought resistant hybri...

  2. A management perspective on the performance of the irrigation subsector.

    NARCIS (Netherlands)

    Nijman, Ch.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the perfo

  3. Alfalfa response to irrigation from limited water supplies

    Science.gov (United States)

    A five-year field study (2007-2011) of irrigated alfalfa production with a limited water supply was conducted in southwest Kansas with two years of above-average precipitation, one year of average precipitation, and two years of below-average precipitation. The irrigation treatments were designed to...

  4. Irrigation Alternatives to Meet Army Net Zero Water Goals

    Science.gov (United States)

    2012-05-01

    Up to 100 Rain Barrel Catchment Up to...US Army Corps of Engineers BUILDING STRONG® Irrigation Alternatives to Meet Army Net Zero Water Goals Richard J. Scholze Dick L. Gebhart H...TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Irrigation Alternatives to Meet Army Net Zero Water Goals 5a. CONTRACT

  5. Small private irrigation: Enhancing benefits and managing trade-offs

    NARCIS (Netherlands)

    Giordano, M.; Fraiture, de C.M.S.

    2014-01-01

    Millions of smallholder farmers in sub-Saharan Africa and South Asia benefit from readily available and affordable irrigation technologies. The rapid uptake of small private irrigation in South Asia had a proven positive effect on poverty alleviation. In sub-Saharan Africa similar trends are emergin

  6. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha

  7. Diagnosing Trouble Spots Caused by an Irrigation System

    Science.gov (United States)

    John R. Scholtes

    2002-01-01

    I discuss a testing procedure to determine the water distribution pattern of a sprinkler irrigation system and steps that may be taken to improve uniformity of application. All irrigation systems require testing and maintenance to assure that water application is as uniform as possible. Even new systems installed to a manufacturer's specifications should be "...

  8. SPRINKLER IRRIGATION AS A VOC SEPARATION AND DISPOSAL METHOD

    Science.gov (United States)

    Sprinkler irrigation is a common farming practice in those states where the semi-arid climate and lack of sufficient rainfall during critical growing periods necessitate the use of supplemental water. The source of most irrigation water is groundwater which can be contaminated wi...

  9. Phosphorus as a limiting factor on sustainable greywater irrigation.

    Science.gov (United States)

    Turner, Ryan D R; Will, Geoffrey D; Dawes, Les A; Gardner, Edward A; Lyons, David J

    2013-07-01

    Water reuse through greywater irrigation has been adopted worldwide and has been proposed as a potential sustainable solution to increased water demands. Despite widespread adoption, there is limited domestic knowledge of greywater reuse. There is no pressure to produce low-level phosphorus products and current guidelines and legislation, such as those in Australia, may be inadequate due to the lack of long-term data to provide a sound scientific basis. Research has clearly identified phosphorus as a potential environmental risk to waterways from many forms of irrigation. To assess the sustainability of greywater irrigation, this study compared four residential lots that had been irrigated with greywater for four years and adjacent non-irrigated lots that acted as controls. Each lot was monitored for the volume of greywater applied and selected physic-chemical water quality parameters and soil chemistry profiles were analysed. The non-irrigated soil profiles showed low levels of phosphorus and were used as controls. The Mechlich3 Phosphorus ratio (M3PSR) and Phosphate Environmental Risk Index (PERI) were used to determine the environmental risk of phosphorus leaching from the irrigated soils. Soil phosphorus concentrations were compared to theoretical greywater irrigation loadings. The measured phosphorus soil concentrations and the estimated greywater loadings were of similar magnitude. Sustainable greywater reuse is possible; however incorrect use and/or lack of understanding of how household products affect greywater can result in phosphorus posing a significant risk to the environment.

  10. The SRFR 5 modeling system for surface irrigation

    Science.gov (United States)

    The SRFR program is a modeling system for surface irrigation. It is a central component of WinSRFR, a software package for the hydraulic analysis of surface irrigation systems. SRFR solves simplified versions of the equations of unsteady open channel flow coupled to a user selected infiltration mod...

  11. Effects of different irrigation programs on yield and quality ...

    African Journals Online (AJOL)

    Jane

    2011-07-11

    Jul 11, 2011 ... This indicated that when irrigation water and ET increased, yield also increased to a certain point. However ... need irrigation water during the all growing period and get adequate benefit ... season is cold and snowy. In Isparta ...

  12. Bureaucratic designs : the paradox of irrigation management transfer in Indonesia

    NARCIS (Netherlands)

    Suhardiman, D.

    2008-01-01

    Irrigation Management Transfer (IMT) policy has been formulated and implemented worldwide, relying on three basic assumptions: that the irrigation agency are motivated to adapt their role in the sector's development; that farmers are willing to take over the system management; and that the process

  13. Remote sensing, GIS and hydrological modelling for irrigation management

    NARCIS (Netherlands)

    Menenti, M.; Azzali, S.; Urso, d' G.

    1996-01-01

    This paper gives an overview of literature and of work done by the authors between 1988 and 1993. It was presented at a NATO expert meeting on sustainability of irrigated agriculture in 1994. The paper deals with crop water requirements and crop waterstress, assessing irrigation performance with

  14. The implication of irrigation in climate change impact assessment

    NARCIS (Netherlands)

    Zhao, Gang; Webber, Heidi; Hoffmann, Holger; Wolf, Joost; Siebert, Stefan; Ewert, Frank

    2015-01-01

    This study evaluates the impacts of projected climate change on irrigation requirements and yields of six crops (winter wheat, winter barley, rapeseed, grain maize, potato, and sugar beet) in Europe. Furthermore, the uncertainty deriving from consideration of irrigation, CO2 effects on

  15. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to accu

  16. Treadle pump irrigation in Malawi: adoption, gender and benefits

    NARCIS (Netherlands)

    Kamwamba-Mtethiwa, J.; Namara, R.; Fraiture, de C.M.S.; Mangisoni, J.; Owusu, E.

    2012-01-01

    As part of their irrigation strategy, the government and non-governmental organizations (NGOs) in Malawi are actively promoting the use of treadle pumps in smallholder irrigation. The positive impact of treadle pumps on food security and poverty reduction in Malawi and elsewhere in sub-Saharan Afric

  17. Infrared thermometry for deficit irrigation of peach trees

    Science.gov (United States)

    Water shortage has been a major concern for crop production in the western states of the USA and other arid regions in the world. Deficit irrigation can be used in some cropping systems as a potential water saving strategy to alleviate water shortage, however, the margin of error in irrigation manag...

  18. Yield Response and Economics of Shallow Subsurface Drip Irrigation Systems

    Science.gov (United States)

    Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

  19. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to accu

  20. Status and migration of irrigation in the USA

    Science.gov (United States)

    Irrigated agriculture produces 49% of crop market value on 18% of cropped lands in the USA. Irrigation is essential to the most highly productive, intensely managed, and internationally competitive sectors of our agricultural economy, which play a key role in meeting growing global food, fiber, and ...

  1. Irrigation Management in the Pamirs in Tajikistan: A Man's Domain?

    NARCIS (Netherlands)

    Bossenbroek, L.; Zwarteveen, M.Z.

    2014-01-01

    Families living in Gorno-Badakhshan—situated in the Pamir Mountains in Tajikistan—depend on irrigated agriculture to meet their subsistence needs. Because men predominate, and are most visible in, the operation and management of irrigation systems in this region, water-related activities are often l

  2. Peanut canopy temperature and NDVI response to varying irrigation rates

    Science.gov (United States)

    Variable rate irrigation (VRI) systems have the potential to conserve water by spatially allocating limited water resources. In this study, peanut was grown under a VRI system to evaluate the impact of differential irrigation rates on peanut yield. Additionally, we evaluated the impact of differenti...

  3. NUTRIENT CONTENT IN SUNFLOWERS IRRIGATED WITH OIL EXPLORATION WATER

    Directory of Open Access Journals (Sweden)

    ADERVAN FERNANDES SOUSA

    2016-01-01

    Full Text Available Irrigation using produced water, which is generated during crude oil and gas recovery and treated by the exploration industry, could be an option for irrigated agriculture in semiarid regions. To determine the viability of this option, the effects of this treated water on the nutritional status of plants should be assessed. For this purpose, we examined the nutritional changes in sunflowers after they were irrigated with oil - produced water and the effects of this water on plant biomass and seed production. The sunflower cultivar BRS 321 was grown for three crop cycles in areas irrigated with filtered produced water (FPW, reverse osmosis - treated produced water (OPW, or ground water (GW. At the end of each cycle, roots, shoots, and seeds were collected to examine their nutrient concentrations. Produced water irrigation affected nutrient accumulation in the sunflower plants. OPW irrigation promoted the accumulation of Ca, Na, N, P, and Mg. FPW irrigation favored the accumulation of Na in both roots and shoots, and biomass and seed production were negatively affected. The Na in the shoots of plants irrigated with FPW increased throughout the three crop cycles. Under controlled conditions, it is possible to reuse reverse osmosis - treated produced water in agriculture. However, more long - term research is needed to understand its cumulative effects on the chemical and biological properties of the soil and crop production.

  4. The politics of policy : participatory irrigation management in Andhra Pradesh

    NARCIS (Netherlands)

    Nikku, B.R.

    2006-01-01

    This thesis studies the emergence, process and politics of the Andhra Pradesh reform policy of Participatory Irrigation Management (PIM). The reform has been labeled as the 'A? model' of irrigation reforms and supported by external aid agencies like World Bank. Within a short span of time Andhra

  5. Atmospheric effects of irrigation in monsoon climate: the Indian subcontinent

    NARCIS (Netherlands)

    Tuinenburg, O.A.

    2013-01-01

    During the 20th century, an increasing population increased the demand for food.  As a consequence, agricultural activity has expanded and become more intense. A  part of this intensification is the use of irrigation systems to water crops. Due to this  irrigation, dams and channeling

  6. Performance evaluation of a center pivot variable rate irrigation system

    Science.gov (United States)

    Variable Rate Irrigation (VRI) for center pivots offers potential to match specific application rates to non-uniform soil conditions along the length of the lateral. The benefit of such systems is influenced by the areal extent of these variations and the smallest scale to which the irrigation syste...

  7. Comparison of the Cleaning Efficacy of Different Final Irrigation Techniques

    NARCIS (Netherlands)

    Jiang, Lei-Meng; Lak, Bram; Eijsvogels, Leonardus M.; Wesselink, Paul; van der Sluis, Lucas W. M.

    2012-01-01

    Introduction: The aim of this study was to evaluate the removal of dentin debris from artificially made grooves in standardized root canals by 6 different final irrigation techniques. Methods: Conventional syringe irrigation, manual dynamic activation (MDA) with tapered or nontapered gutta-percha (G

  8. land evaluation for improved rice production in watari irrigation ...

    African Journals Online (AJOL)

    DR. AMINU

    directly related to quality and suitability of soil, and as ... mapping and monitoring land use changes. ... the consequences of land use/land cover changes is ... The ecology of the Watari Irrigation project is Sudan ... mapping units identified as suitable for irrigation by .... adequate rice production, sufficient quantity of water.

  9. Groundwater Suitability for Irrigation: a Case Study from Debre ...

    African Journals Online (AJOL)

    Bheema

    irrigation water quality, the groundwater is suitable for irrigation with some minor ... specific toxicity effect on vegetables and field crops, however, there are ... alone cannot sustain the practice, the issues like ecological and social are to be taken in to ... particularly for crops that are sensitive to changes in quality (Bohn et al., ...

  10. Development of guidance for sustainable irrigation use of greywater ...

    African Journals Online (AJOL)

    as ecological sanitation (EcoSan) have arisen to address this .... be long-term effects, while effects on plant growth and yield .... in food crops irrigated with mixed domestic greywater (Rodda ..... of E0 in place of point estimates, or using the SAPWAT model ..... STANDEN R and McGUCKIAN R (2000) Developing irrigation.

  11. The management perspective on the performance of the irrigation subsector

    NARCIS (Netherlands)

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the perfo

  12. Irrigation analysis based on long-term weather data

    Science.gov (United States)

    Irrigation-management is based upon delivery of water to a crop in the correct amount and time, and the crop’s water need is determined by calculating evapotranspiration (ET) using weather data. In 1994 an ET-network was established in the Texas High Plains to manage irrigation on a regional scale. ...

  13. Efficient irrigation management with conventional and VRI sprinkler systems

    Science.gov (United States)

    In Alabama, there is a ploitical push towards irrigated agriculture, as reduction in water resources for agriculture in the West becomes more limited. Some farmers have invested in center pivot systems but have little experience with irrigation scheduling methods. ARS scientists at Bushland have e...

  14. Bureaucratic designs : the paradox of irrigation management transfer in Indonesia

    NARCIS (Netherlands)

    Suhardiman, D.

    2008-01-01

    Irrigation Management Transfer (IMT) policy has been formulated and implemented worldwide, relying on three basic assumptions: that the irrigation agency are motivated to adapt their role in the sector's development; that farmers are willing to take over the system management; and that the process o

  15. Next generation sequencing of oomycete communities in nursery irrigation water

    Science.gov (United States)

    Joyce Eberhart; Fumiaki Funahashi; Zachary S.L. Foster; Jennifer Parke

    2017-01-01

    Horticultural nurseries are under increasing pressure to reduce, remediate, and recycle irrigation water. A major constraint for reusing irrigation water is contamination by waterborne plant pathogenic Phytophthora and Pythium species. Current research is focused on helping plant nurseries monitor oomycete pathogens in...

  16. Irrigation and the demand for electricity. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Maddigan, R. J.; Chern, W. S.; Gallagher, C. A.

    1980-03-01

    In order to anticipate the need for generating capacity, utility planners must estimate the future growth in electricity demand. The need for demand forecasts is no less important for the nation's Rural Electric Cooperatives (RECs) than it is for the investor-owned utilities. The RECs serve an historically agrarian region; therefore, the irrigation sector accounts for a significant portion of the western RECs' total demand. A model is developed of the RECs' demand for electricity used in irrigation. The model is a simultaneous equation system which focuses on both the short-run utilization of electricity in irrigation and the long-run determination of the number of irrigators using electricity. Irrigation demand is described by a set of equations in which the quantity of electricity demanded, the average electricity price, the number of irrigation customers, and the ratio of electricity to total energy used for irrigation are endogenous. The structural equations are estimated using pooled state-level data for the period 1961-1977. In light of the model's results, the impact of changes in relative energy prices on irrigation can be examined.

  17. Wedlock or deadlock? Feminists' attempts to engage irrigation engineers

    NARCIS (Netherlands)

    Zwarteveen, M.Z.

    2006-01-01

    In this thesis I describe my search for ways of thinking about, and conceptualizing, irrigation realities that allow recognition of gender as constitutive of such realities. This effort logically follows from the realization that in mainstream conceptualizations of irrigation it is difficult to

  18. The management perspective on the performance of the irrigation subsector

    NARCIS (Netherlands)

    Nijman, C.

    1993-01-01

    INVESTMENT IN IRRIGATION has been immense in the past. Estimated average annual investments of US$ 15 billion makes irrigation the largest subsector of the agricultural sector, that is itself by far the largest sector of development investment. Since the mid-1960s the awareness spread that the

  19. Technology transfer: Promoting irrigation progress and best management practices

    Science.gov (United States)

    Educational efforts promoting irrigation best management practices are designed to increase adoption of these practices and increase public understanding of the importance of irrigation. They increase visibility and the impact of the Ogallala Aquifer Program and promote affiliated research and exten...

  20. The politics of policy : participatory irrigation management in Andhra Pradesh

    NARCIS (Netherlands)

    Nikku, B.R.

    2006-01-01

    This thesis studies the emergence, process and politics of the Andhra Pradesh reform policy of Participatory Irrigation Management (PIM). The reform has been labeled as the 'A? model' of irrigation reforms and supported by external aid agencies like World Bank. Within a short span of time Andhra Pra

  1. Consumptive Water Use and Crop Coefficients of Irrigated Sunflower

    Science.gov (United States)

    In semi-arid environments, the use of irrigation is necessary for sunflower production to reach its maximum potential. The aim of this study was to quantify the consumptive water use and crop coefficients of irrigated sunflower (Helianthus annuus L.) without soil water limitations during two growing...

  2. Micro-irrigation systems, automation and fertigation in citrus

    Directory of Open Access Journals (Sweden)

    Parameshwar Sidramappa Shirgure

    2012-11-01

    Full Text Available Citrus is number one group of fruits grown in more than 140 countries in the world. Micro-irrigation systems and fertigation management is one of the main concerns of the modem citrus fruit production irrespective of availability of soil, water and fertilizer resources. A variety of recommendations have emerged world over on irrigation systems and fertigation based on soil and leaf analysis of the nutrients, evapo-transpiration and water use pattern. The research review of literature has revealed best promising results on irrigation scheduling based on depletion pattern of soil available water content, irrigation systems and fertigation. Various micro-irrigation systems have established their superiority over traditionally used flood irrigation with micro-jets having little edge over rest of the others. Similarly, fertigation has shown good responses on growth, yield, quality and uniform distribution pattern of applied nutrients within the plant rootzone compared to band placement involving comparatively localized fertilization. Automated fertigation in citrus orchards is a new concept, which would be the only solitary choice amongst many irrigation monitoring methods in near future. The present status of the review on micro-irrigation and fertigation in citrus cultivars is clearly indicated in this article.

  3. Size and stochasticity in irrigated social-ecological systems

    Science.gov (United States)

    Puy, Arnald; Muneepeerakul, Rachata; Balbo, Andrea L.

    2017-01-01

    This paper presents a systematic study of the relation between the size of irrigation systems and the management of uncertainty. We specifically focus on studying, through a stylized theoretical model, how stochasticity in water availability and taxation interacts with the stochastic behavior of the population within irrigation systems. Our results indicate the existence of two key population thresholds for the sustainability of any irrigation system: or the critical population size required to keep the irrigation system operative, and N* or the population threshold at which the incentive to work inside the irrigation system equals the incentives to work elsewhere. Crossing irretrievably leads to system collapse. N* is the population level with a sub-optimal per capita payoff towards which irrigation systems tend to gravitate. When subjected to strong stochasticity in water availability or taxation, irrigation systems might suffer sharp population drops and irreversibly disintegrate into a system collapse, via a mechanism we dub ‘collapse trap’. Our conceptual study establishes the basis for further work aiming at appraising the dynamics between size and stochasticity in irrigation systems, whose understanding is key for devising mitigation and adaptation measures to ensure their sustainability in the face of increasing and inevitable uncertainty. PMID:28266656

  4. Role of vegetation (Typha latifolia) on nutrient removal in a horizontal subsurface-flow constructed wetland treating UASB reactor-trickling filter effluent.

    Science.gov (United States)

    da Costa, Jocilene Ferreira; Martins, Weber Luiz Pinto; Seidl, Martin; von Sperling, Marcos

    2015-01-01

    The main objective of the work is to characterize the role of plants in a constructed wetland in the removal of nitrogen (N) and phosphorus (P). The experiments were carried out in a full-scale system in the city of Belo Horizonte, Brazil, with two parallel horizontal subsurface-flow constructed wetland units (one planted with Typha latifolia and one unplanted) treating the effluent from a system composed of an upflow anaerobic sludge blanket reactor and a trickling filter (TF). Each wetland unit received a mean flow of approximately 8.5 m³ d⁻¹ (population equivalent around 60 inhabitants each), with a surface hydraulic loading rate 0.12 m³m⁻²d⁻¹. The experiments were conducted from September 2011 to July 2013. Mean effluent concentrations from the wetlands were: (a) planted unit total nitrogen (TN) 22 mg L⁻¹, ammonia-N 19 mg L⁻¹, nitrite-N 0.10 mg L⁻¹, nitrate-N 0.25 mg L⁻¹, P-total 1.31 mg L⁻¹; and (b) unplanted unit TN 24 mg L⁻¹, ammonia-N 20 mg L⁻¹, nitrite-N 0.54 mg mL⁻¹, nitrate-N 0.15 mg L⁻¹, P-total 1.31 mg L⁻¹. The aerial part of the plant contained mean values of 24.1 gN (kg dry matter)⁻¹ and 4.4 gP (kg dry matter)⁻¹, and the plant root zone was composed of 16.5 gN (kg dry matter)⁻¹ and 4.1 gP (kg dry matter)⁻¹. The mean extraction of N by the plant biomass was 726 kgN ha⁻¹y⁻¹, corresponding to 17% of the N load removed. For P, the extraction by the plant biomass was 105 kgP ha⁻¹y⁻¹, corresponding to 9% of the P load removed. These results reinforce the reports that N and P removal due to plant uptake is a minor mechanism in horizontal subsurface-flow constructed wetlands operating under similar loading rates, typical for polishing of sanitary effluent.

  5. SMART IRRIGATION TECHNIQUE USING VOCAL COMMANDS

    Directory of Open Access Journals (Sweden)

    V.Divya

    2013-02-01

    Full Text Available In this wireless communication era, mobile phones have become a necessity in the common man’s life. Besides being capable of making calls and sending messages, the latest advancements in mobile phones facilitate them to connect to the internet also. With these capabilities, there has been an unprecedented use of mobile phones in many areas of automation. One such area where mobile phone can help with the automation is irrigation process. The main aim of the work is to simplify the method of irrigation using vocal commands through the mobile phone. The Farmer just needs to call a fixed number and utter the control commands through his phone. The control system at the field involves a PIC microcontroller interfaced with GSM modem to receive the command from the farmer and a voice recognition unit which decodes it. The motor is turned on/off according to the decoded commands by the controller. In addition, the system also sends back a message to the farmer’s mobile about the action that has taken place. The power detection and battery backup unit helps in detecting the power availability in the field and inform the farmer about the same, even if the there is no supply at the field. The moisture sensor attached to the system helps in collecting the moisture content of the soil and switch off the motor after it reaches the required value.

  6. PRODUCTION OF TOMATO SEEDLINGS UNDER SALINE IRRIGATION

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Brasiliano Campos

    2007-01-01

    Full Text Available Processing tomato is the most important vegetable crop of the Brazilian agribusiness and few researches have been conducted to evaluate the tolerance of this crop to saline stress. In this study, the effects of five levels of salinity of the irrigation water (1, 2, 3, 4 and 5 dS m-1 and three equivalent proportions of Na:Ca:Mg (1:1:0.5, 4:1:0.5 and 7:1:0.5 were tested on the emergence and vigor of processing tomato, cultivar IPA 6. Seeds were sowed in expanded polystyrene tray (128 cells and each tray received 1 L of water after sowing. The trays were piled and, four days after sowing, they were placed on suspended supports in a greenhouse. Irrigation was accomplished daily from the fifth day after sowing. Only dry weight of shoot and root was affected by sodium proportions, while linear reductions of the speed of emergence, stem length and the dry weight of shoot and root were observed with increasing salinity. Root was more affected than shoot by salinity and relative growth ratioincreased with salinity levels on the 14-21 days after sowing period, indicating that the crop showed a certain increase of salinity tolerance with the time of exposure to salts.

  7. Estimates of Savings Achievable from Irrigation Controller

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Alison; Fuchs, Heidi; Whitehead, Camilla Dunham

    2014-03-28

    This paper performs a literature review and meta-analysis of water savings from several types of advanced irrigation controllers: rain sensors (RS), weather-based irrigation controllers (WBIC), and soil moisture sensors (SMS).The purpose of this work is to derive average water savings per controller type, based to the extent possible on all available data. After a preliminary data scrubbing, we utilized a series of analytical filters to develop our best estimate of average savings. We applied filters to remove data that might bias the sample such as data self-reported by manufacturers, data resulting from studies focusing on high-water users, or data presented in a non-comparable format such as based on total household water use instead of outdoor water use. Because the resulting number of studies was too small to be statistically significant when broken down by controller type, this paper represents a survey and synthesis of available data rather than a definitive statement regarding whether the estimated water savings are representative.

  8. Experience with irrigation analgesia after abdominal hysterectomy

    Directory of Open Access Journals (Sweden)

    R. V. Garyaev

    2012-01-01

    Full Text Available A prospective randomized clinical trial was performed in 100 patients who underwent abdominal hysterectomy under endotracheal anesthesia based on sevoflurane and fentanyl. Intraoperatively, ketorolac 30 mg was administered intramuscularly after induction of anesthesia and paracetamol 1 g was injected intravenously 30–40 minutes prior to surgical termination in a control group (n = 25. For postoperative anal- gesia, promedol, tramadol, and ketorolac were used intramuscularly and paracetamol was given intravenously. Three study groups (n = 2 in each differed from the control group in that during wound suturing a multiperforated catheter was placed above the peritoneum over a length of 15 cm, through which a 10-ml bolus of 0.75 % ropivacaine was first administered, followed by continuous infusion of 0.2 % ropivacaine at a rate of 8 ml/hour for 36 hours. In one irrigation group, ketorolac 30 mg was injected intramuscularly t.i.d. for 2 days; in another group, the agent was added to a ropivacaine solution calculated with reference to 180 mg for 2 days; in the third group, ketoprofen 100 mg instead of ketorolac was used b.i.d. for 2 days. Pain level (by digital rating scale, 0–10 and the need for analgesics were measured. There was no sta- tistical significant difference in the level of pain and the need for analgesics between the wound irrigation and control groups.

  9. Non-sustainable groundwater sustaining irrigation - a global assessment

    Science.gov (United States)

    Wada, Y.; van Beek, L. P. H.; Bierkens, M. F. P.

    2012-04-01

    Irrigated crops play a vital role in securing global food production. It is estimated that 17% of agricultural lands are irrigated, yet they account for 40% of the global food production, sustaining the livelihood of billions of people (Abdullah, 2006). At the same time, water used by irrigated crops (i.e., crop water demand) and irrigation water demand are responsible for about 70% of the global water withdrawal and account for about 90% of the global water consumption, i.e. water withdrawal minus return flow respectively. Water demand for irrigated crops can be met by three different sources: 1) green water, being water from local precipitation that is temporarily stored in the soil, 2) blue water, being surface freshwater available in rivers, lakes, reservoirs and wetlands, and renewable groundwater, and 3) non-renewable or non-sustainable groundwater and non-local water resources. Here, we quantify globally the amount of non-renewable groundwater abstraction to sustain current irrigation practice. We use the global hydrological model PCR-GLOBWB to simulate gross crop water demand for irrigated crops and available blue and green water to meet this demand. We downscale country statistics of groundwater abstraction by considering the part of net total water demand that cannot be met by surface freshwater. We subsequently confront these with simulated groundwater recharge including return flow from irrigation to estimate non-renewable groundwater abstraction. Results show that non-renewable groundwater abstraction contributes approximately 20% to the global gross irrigation water demand for the year 2000. The contribution of non-renewable groundwater abstraction to irrigation is largest in India (68 km3 yr-1) followed by Pakistan (35 km3/yr), USA (30 km3/yr), Iran (20 km3/yr), China (20 km3/yr), Mexico (10 km3/yr) and Saudi Arabia (10 km3/yr). Results also show that globally this contribution more than tripled from 75 to 234 km3/yr over the period 1960-2000. These

  10. Sustainable Irrigation with Brackish Groundwater in Heilonggang Region, China

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Saline groundwater is widely distributed in Heilonggang region. While deep confined water is being mined, saline water has not been used in most part of the region. Extension of saline water irrigation is of significance to resolve water shortage, slow down environmental degradation and support the sustainable development of the local agriculture. Four key points are proposed to be managed by comprehensive measures: (1) adapting salt-resistant ability; (2) reducing salt input; (3) decreasing soil surface evaporation and salt accumulation in the root zone, and (4) washing away salt from the root zone. Experiments and farming practices demonstrated that brackish water with TDS (total dissolved solids) of 2-5 g/l can be used for crop irrigation. For example, winter wheat can be sustainably irrigated by brackish water with a water limitation of 120 mm every year. Irrigation in combination with different comprehensive measures can increase the efficiency of saline water irrigation.

  11. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    leaching without compromising profits. Four replicate plots of each treatment with varying predefined and model-based (Daisy and Aquacrop crop model) irrigation and N fertilization levels were used in the study. Two experiments were conducted. In experiment-I, treatments consisted of one drip......The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P...

  12. Response of potato to drip and gun irrigation systems

    DEFF Research Database (Denmark)

    Zhenjiang, Zhou; Andersen, Mathias Neumann; Plauborg, Finn

    2015-01-01

    The objective of this study was to evaluate effects of different irrigation and N fertilization regimes by gun irrigation and drip-fertigation on potato production, and subsequently optimize the supply of water and N fertilizer to the growth condition of the specific season and minimize nitrate......-fertigation system (DFdsNds) and two gun irrigation systems (GIdsN120 and GIaN120) to display the differences on growth, yield and water use efficiency of potato. All treatments were irrigated according to model simulated soil water content. For fertilization all treatments received a basic dressing at planting of P......, K, Mg and micronutrients, and in addition 120 kg N/ha in the gun irrigated treatments and 36 kg N/ha in the drip-fertigated. For the latter, portion of 20 kg N/ha was applied whenever plant N concentration approached a critical value as simulated by the Daisy model. As a result differences in soil...

  13. Irrigated lands assessment for water management: Technique test. [California

    Science.gov (United States)

    Wall, S. L.; Brown, C. E.; Eriksson, M.; Grigg, C. A.; Thomas, R. W.; Colwell, R. N.; Estes, J. E.; Tinney, L. R.; Baggett, J. O.; Sawyer, G.

    1981-01-01

    A procedure for estimating irrigated land using full frame LANDSAT imagery was demonstrated. Relatively inexpensive interpretation of multidate LANDSAT photographic enlargements was used to produce a map of irrigated land in California. The LANDSAT and ground maps were then linked by regression equations to enable precise estimation of irrigated land area by county, basin, and statewide. Land irrigated at least once in California in 1979 was estimated to be 9.86 million acres, with an expected error of less than 1.75% at the 99% level of confidence. To achieve the same level of error with a ground-only sample would have required 3 to 5 times as many ground sample units statewide. A procedure for relatively inexpensive computer classification of LANDSAT digital data to irrigated land categories was also developed. This procedure is based on ratios of MSS band 7 and 5, and gave good results for several counties in the Central Valley.

  14. Using Cotton Model Simulations to Estimate Optimally Profitable Irrigation Strategies

    Science.gov (United States)

    Mauget, S. A.; Leiker, G.; Sapkota, P.; Johnson, J.; Maas, S.

    2011-12-01

    In recent decades irrigation pumping from the Ogallala Aquifer has led to declines in saturated thickness that have not been compensated for by natural recharge, which has led to questions about the long-term viability of agriculture in the cotton producing areas of west Texas. Adopting irrigation management strategies that optimize profitability while reducing irrigation waste is one way of conserving the aquifer's water resource. Here, a database of modeled cotton yields generated under drip and center pivot irrigated and dryland production scenarios is used in a stochastic dominance analysis that identifies such strategies under varying commodity price and pumping cost conditions. This database and analysis approach will serve as the foundation for a web-based decision support tool that will help producers identify optimal irrigation treatments under specified cotton price, electricity cost, and depth to water table conditions.

  15. Comparison of water distribution mechanisms under two localized irrigation techniques (Drip Irrigation & Buried Diffuser) for one week irrigation period in a sandy soil of southeastern Tunisia

    Science.gov (United States)

    Gasmi, Ines; Kodešová, Radka; Mechergui, Mohamed; Nikodem, Antonín; Moussa, Mohamed

    2017-04-01

    The majority of agricultural ecosystems in the Mediterranean basin of northern Africa suffer from water shortage and positions these regions in a highly vulnerable to climate change. In arid regions of Tunisia and exactly in the Southeastern part, during each growing season, plant productivity in sandy-loamy soils is dramatically reduced by limited availability of soil water and nutrients. Thus, highly permeable soils are unable to retain adequate water and nutrient resource in the plant root zone. Moreover, the investments of supplemental irrigation and agricultural amendments of additional fertilization are not sustainable due to the leaching of water supplies and nutrients, which severely limit agricultural productivity. In addition, inadequate soil water distribution, costly irrigation and fertilization leads to negative responses to plant nutrients added to highly permeable soils. That's why we should use irrigation techniques with high water use efficiency. This paper focuses on the comparison between two localized irrigation techniques which are the Drip Irrigation (DI) and the Buried Diffuser (BD) that has the same flow rates (4 l/h). The BD is buried at 15 cm depths. Experimental data was obtained from Smar-Médenine located in South-East of Tunisia. The water distribution at the soil surface for BD is very important about 195 cm2 while for the DI is about 25.12 cm2. The HYDRUS 2D/3D model helped to evaluate the water distribution and compare the water balance obtained with those two irrigation techniques for one week irrigation period. There is a rapid kinetic which has a duration of 3 hours (irrigation time) and a slow kinetic which is the result of the water distribution in the soil, the plant uptake and the effect of climatic condition. There are two mechanisms that affect the two irrigation techniques: the water distribution and the position of irrigation system. As a result, irrigation with BD goes dipper in the soil. The transmission zone for this

  16. Irrigation water policy analysis using a business simulation game

    Science.gov (United States)

    Buchholz, M.; Holst, G.; Musshoff, O.

    2016-10-01

    Despite numerous studies on farmers' responses to changing irrigation water policies, uncertainties remain about the potential of water pricing schemes and water quotas to reduce irrigation. Thus far, policy impact analysis is predominantly based upon rational choice models that assume behavioral assumptions, such as a perfectly rational profit-maximizing decision maker. Also, econometric techniques are applied which could lack internal validity due to uncontrolled field data. Furthermore, such techniques are not capable of identifying ill-designed policies prior to their implementation. With this in mind, we apply a business simulation game for ex ante policy impact analysis of irrigation water policies at the farm level. Our approach has the potential to reveal the policy-induced behavioral change of the participants in a controlled environment. To do so, we investigate how real farmers from Germany, in an economic experiment, respond to a water pricing scheme and a water quota intending to reduce irrigation. In the business simulation game, the participants manage a "virtual" cash-crop farm for which they make crop allocation and irrigation decisions during several production periods, while facing uncertain product prices and weather conditions. The results reveal that a water quota is able to reduce mean irrigation applications, while a water pricing scheme does not have an impact, even though both policies exhibit equal income effects for the farmers. However, both policies appear to increase the variation of irrigation applications. Compared to a perfectly rational profit-maximizing decision maker, the participants apply less irrigation on average, both when irrigation is not restricted and when a water pricing scheme applies. Moreover, the participants' risk attitude affects the irrigation decisions.

  17. Greywater reuse for irrigation: effect on soil properties.

    Science.gov (United States)

    Travis, Micheal J; Wiel-Shafran, Alit; Weisbrod, Noam; Adar, Eilon; Gross, Amit

    2010-05-15

    A controlled study of the effect of greywater (GW) irrigation on soil properties was conducted. Containers of sand, loam and loess soils were planted with lettuce, and irrigated with fresh water, raw artificial GW or treated artificial GW. Greywater was treated using a recirculating vertical-flow constructed wetland. Soil samples were collected every 10 days for the 40-day duration of the study, and plant growth was measured. Soils were analysed for physicochemical and biological parameters to determine changes caused by the different treatments. It was demonstrated that raw artificial GW significantly increased the development of hydrophobicity in the sand and loam soils, as determined by water droplet penetration time. No significant changes were observed for the loess soil under all treatments. Observed hydrophobicity was correlated with increased oil and grease and surfactant concentrations in the soil. Zeta (zeta) potential of the soils was measured to determine changes in the soil particle surface properties as a result of GW irrigation. A significant change in zeta-potential (less negative) was observed in the raw artificial GW-irrigated sand, whereas no difference was observed in the loam or loess. Soils irrigated with fresh water or treated GW exhibited no increase in hydrophobicity. Fecal coliform bacteria were absent or <10 CFU g(-1) in soils irrigated with fresh water or treated GW, but at least 1 order of magnitude higher in raw artificial GW irrigated soils. Only in the last sampling event and only for the loess soil was plant growth significantly higher for fresh water irrigated vs. raw or treated GW irrigated soils. This study demonstrates that treated GW can be effectively irrigated without detrimental effects on soil or plant growth; however, raw GW may significantly change soil properties that can impact the movement of water in soil and the transport of contaminants in the vadose zone.

  18. Sustainability of irrigated crops under future climate: the interplay of irrigation strategies and cultivar responses

    Science.gov (United States)

    De Lorenzi, F.; Bonfante, A.; Alfieri, S.; Patanè, C.; Basile, A.; Di Tommasi, P.; Monaco, E.; Menenti, M.

    2012-04-01

    Climate evolution will cause significant changes in the quality and availability of water resources, affecting many sectors including food production, where available water resources for irrigation play a crucial role. Strategies focused on managing and conserving water are one way to deal with the impact; moreover concurring adaptation measurements will be needed to cope with the foreseen decline of water resource. This work deals with i) the impacts of climate change on water requirements of an horticultural crop, determined in an irrigated district in Southern Italy, ii) the possible irrigation scheduling options and their sustainability in the future, iii) the adaptation measurements that can be undertaken to protect production, relying on intra-specific biodiversity of agricultural crops. Two climate scenarios were considered: present climate (1961-90) and future climate (2021-2050), the former from climatic statistics, and the latter from statistical downscaling of general circulation models (AOGCM). Climatic data set consists of daily time series of maximum and minimum temperature, and rainfall on a grid with spatial resolution of 35 km. The analysis of climate scenarios showed that significant increases in summer maximum daily temperature could be expected in 2021-2050 period. Soil water regime was determined by means of a mechanistic model (SWAP) of water flow in the soil-plant-atmosphere system. Twenty? soil units were identified in the district (in Sele Plain, Campania Region) and simulations were performed accounting for hydro-pedological properties of different soil units. Parameters of a generic tomato crop, in a rotation typical of the area, were used in simulations. Soil water balance was simulated in the present and future climate, both with optimal water availability and under constrains that irrigation schemes will pose. Indicators of soil water availability were calculated, in terms of soil water or evapotranspiration deficit. For several tomato

  19. A new method for real-time quantification of irrigant extrusion during root canal irrigation ex vivo

    NARCIS (Netherlands)

    Psimma, Z.; Boutsioukis, C.; Vasiliadis, L.; Kastrinakis, E.

    2013-01-01

    Aim (i) To introduce a new method of quantifying extruded irrigant during root canal irrigation ex vivo. (ii) to evaluate the effect of periapical tissue simulation and pressure equalization and (iii) to determine the effect of needle type, apical preparation size and apical constriction diameter

  20. Agro-Ecology and Irrigation Technology : Comparative Research on Farmer-Management Irrigation Systems in the Mid- Hills of Nepal

    NARCIS (Netherlands)

    Parajuli, U.N.

    1999-01-01

    Design and management of irrigation infrastructure in farmer managed irrigation systems (FMISs) are strongly influenced by social and agro-ecological conditions of an area. This thesis analyzes the elements of social and agro-ecological conditions in FMISs in the mid-hills of Nepal and examines thei

  1. Comparative effects of partial root-zone irrigation and deficit irrigation on phosphorus uptake in tomato plants

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Jensen, Christian Richardt

    2012-01-01

    The comparative effects of partial root-zone irrigation (PRI) and deficit irrigation (DI) on phosphorus (P) uptake in tomato (Lycopersicon esculentum Mill.) plants were investigated in a split-root pot experiment. The results showed that PRI treatment improved water-use efficiency (WUE) compared...

  2. Can subsurface drip irrigation (SDI) be a competitive irrigation system in the Great Plains region for commodity crops

    Science.gov (United States)

    Subsurface drip irrigation (SDI) as with all microirrigation systems is typically only used on crops with greater value. In the U.S. Great Plains region, the typical irrigated crops are the cereal and oil seed crops and cotton. These crops have less economic revenue than typical microirrigated cro...

  3. Experimental Investigation of Soil Evaporation and Evapotranspiration of Winter Wheat Under Sprinkler Irrigation

    Institute of Scientific and Technical Information of China (English)

    YU Li-peng; HUANG Guan-hua; LIU Hai-jun; WANG Xiang-ping; WANG Ming-qiang

    2009-01-01

    Sprinkler irrigation is one of the typical irrigation technologies used for the winter wheat-summer maize double cropping system in the North China Plain. To evaluate the evapotranspiration (ET) of winter wheat under sprinkler irrigation in Beijing area, field experiments were conducted in growing seasons through 2005-2008, in the experimental station located in Tongzhou County, Beijing, China, with different irrigation depths. Results indicated that a relatively large variation of soil water content occurred within 0-40 cm soil layer. The seasonal ET of winter wheat generally increased with increasing irrigation amount, while the seasonal usage of soil water had a negative relationship with irrigation amount. Soil evaporation (Es) was about 25% of winter wheat ET during the period from reviving to maturity. Es increased while Es/ET decreased with increasing irrigation amount. Sprinkler irrigation scheduling with relatively large irrigation quota and low irrigation frequency can reduce E, and promote the irrigation water use efficiency.

  4. Estimating irrigation water use in the humid eastern United States

    Science.gov (United States)

    Levin, Sara B.; Zarriello, Phillip J.

    2013-01-01

    Accurate accounting of irrigation water use is an important part of the U.S. Geological Survey National Water-Use Information Program and the WaterSMART initiative to help maintain sustainable water resources in the Nation. Irrigation water use in the humid eastern United States is not well characterized because of inadequate reporting and wide variability associated with climate, soils, crops, and farming practices. To better understand irrigation water use in the eastern United States, two types of predictive models were developed and compared by using metered irrigation water-use data for corn, cotton, peanut, and soybean crops in Georgia and turf farms in Rhode Island. Reliable metered irrigation data were limited to these areas. The first predictive model that was developed uses logistic regression to predict the occurrence of irrigation on the basis of antecedent climate conditions. Logistic regression equations were developed for corn, cotton, peanut, and soybean crops by using weekly irrigation water-use data from 36 metered sites in Georgia in 2009 and 2010 and turf farms in Rhode Island from 2000 to 2004. For the weeks when irrigation was predicted to take place, the irrigation water-use volume was estimated by multiplying the average metered irrigation application rate by the irrigated acreage for a given crop. The second predictive model that was developed is a crop-water-demand model that uses a daily soil water balance to estimate the water needs of a crop on a given day based on climate, soil, and plant properties. Crop-water-demand models were developed independently of reported irrigation water-use practices and relied on knowledge of plant properties that are available in the literature. Both modeling approaches require accurate accounting of irrigated area and crop type to estimate total irrigation water use. Water-use estimates from both modeling methods were compared to the metered irrigation data from Rhode Island and Georgia that were used to

  5. Yield and Irrigation Water Use Efficiency Response of Chufa (Cyperus esculentus L. var. sativus Boeck.) to Drip Irrigation Management

    Science.gov (United States)

    Pascual-Seva, Nuria; San Bautista, Alberto; López-Galarza, Salvador; Maroto, José Vicente; Pascual, Bernardo

    2016-04-01

    Chufa, also known as tigernut, is a typical crop in Valencia, Spain, where it is cultivated in ridges with furrow irrigation. Its cultivation uses large amounts of water, in the order of 10,000 m3 ha-1 year-1, so different studies have been undertaken in order to maximize the irrigation water use efficiency (IWUE). One of these studies faced the application of drip irrigation in the chufa cultivation, comparing three different irrigation strategies. These strategies differed on the volumetric soil water content (VSWC) when each irrigation event started. Starting each irrigation when the VSWC dropped to 90% of field capacity (FC) leaded to the highest yield, while the highest IWUE was obtained when irrigation started at 80% FC. It can be stated that starting each irrigation event when the VSWC is between 80 and 90% FC leads to the best results in terms of yield and IWUE. However, these results may still be improved by defining the best strategy in the irrigation stop, which is the aim of the herein presented research. This investigation comprises the productive response of the chufa crop with drip irrigation, determining yield and IWUE. The VSWC was monitored using multi-depth capacitance probes, with sensors at 0.10, 0.20 and 0.30 m below the top of the ridge. Each irrigation event started when the volumetric soil water content at 0.10 m dropped to 85% FC. Three irrigation strategies were considered, T1: each event being stopped when the average of the VSWC values at 0.10, 0.20 and 0.30 m depth reached the corresponding FC value; T2: each event being stopped when the VSWC values at 0.20 m reached the corresponding FC value; T3 each irrigation event lasted 30 min (corresponding to 7.33 mm). The largest yield (P ≤0.05) was obtained in T2 (2.31 kg m-2), with no statistical differences (P ≤0.05) between T1 (1.94 kg m-2) and T3 (1.92 kg m-2). The highest yield in T2 was obtained with the largest volume of irrigation water applied (722 mm), resulting in the lowest (P

  6. On-irrigator pasture soil moisture sensor

    Science.gov (United States)

    Eng-Choon Tan, Adrian; Richards, Sean; Platt, Ian; Woodhead, Ian

    2017-02-01

    In this paper, we presented the development of a proximal soil moisture sensor that measured the soil moisture content of dairy pasture directly from the boom of an irrigator. The proposed sensor was capable of soil moisture measurements at an accuracy of  ±5% volumetric moisture content, and at meter scale ground area resolutions. The sensor adopted techniques from the ultra-wideband radar to enable measurements of ground reflection at resolutions that are smaller than the antenna beamwidth of the sensor. An experimental prototype was developed for field measurements. Extensive field measurements using the developed prototype were conducted on grass pasture at different ground conditions to validate the accuracy of the sensor in performing soil moisture measurements.

  7. Saline Nasal Irrigation for Upper Respiratory Conditions

    Science.gov (United States)

    2009-01-01

    Acute and chronic upper respiratory conditions are common and expensive disorders with enormous impact on patient quality of life and society at large. Saline nasal irrigation (SNI), a therapy with roots in Ayurvedic medicine that bathes the nasal mucosa with in spray or liquid saline, has been used as adjunctive care for upper respiratory conditions. In liquid form, SNI has been found to be effective adjunctive care by the Cochrane Collaboration for symptoms associated with chronic rhinosinusitis. Less conclusive clinical trial evidence supports its use in spray and liquid forms as adjunctive treatment for mild-to-moderate allergic rhinitis and acute upper respiratory infections. Consensus or expert opinion recommendations exist for SNI as a treatment for a variety of other conditions including rhinitis of pregnancy. SNI appears safe; side effects are minimal and transient. It can be recommended by clinicians to interested patients with a range of upper respiratory conditions in the context of patient education and printed instructional handouts. PMID:19904896

  8. Subsurface drip irrigation in different planting spacing of sugarcane

    Science.gov (United States)

    Pires, R. C. M.; Barbosa, E. A. A.; Arruda, F. B.; Silva, T. J. A.; Sakai, E.; Landell, M. G. A.

    2012-04-01

    The use of subsurface drip irrigation (SDI) in sugarcane cultivation is an interesting cultural practice to improve production and allow cultivation in marginal lands due to water deficits conditions. The SDI provides better water use efficiency, due to the water and nutrients application in root zone plants. However, it is important to investigate the long-term effect of irrigation in the yield and technological quality in different ecological condition cultivation. Thus, the aim of this work was to evaluate the effect of SDI in sugarcane cultivated in different planting spacings on technological quality, yield and theoretical recoverable sugar during four cycles of sugarcane cultivation. The experiment was carried out at Colorado Mill, Guaíra, São Paulo State in Brazil, in a clay soil. The experiment was installed in randomized blocks, with six replications. The treatments were three different planting spacings (S1 - 1.5 m between rows; S2 - 1.8 m between rows and S3 - planting in double line of 0.5 m x 1.3 m between planting rows) which were subdivided in irrigated and non-irrigated plots. In S1 and S2 treatments were installed one drip line in each plant row and in treatment S3 one drip line was installed between the rows with smaller spacing (0.5 m). The RB855536 genotype was used and the planting date occurred in May, 25th 2005. The analyzed parameters were: percentage of soluble solids (brix), percent apparent sucrose juice (Pol), total recoverable sugar (ATR), yield and theoretically recoverable sugar (RTR). Four years of yield (plant cane and first, second and third ratoon) were analyzed. Data were submitted to variance analysis and the averages compared by Duncan test at 5% probability. Two months before the first harvest a yield estimate was realized. According to the observed results the irrigated plants provided increase of about 20 % compared to non irrigated plants. However there was a great tipping of plants specially in irrigated plots. The

  9. EFFICACY OF DIFFERENT ENDODONTIC IRRIGATION PROTOCOLS IN CALCIUM HYDROXIDE REMOVAL

    Directory of Open Access Journals (Sweden)

    Elka N. Radeva

    2016-10-01

    Full Text Available Introduction: Calcium hydroxide is widely used in the field of endodontics as a temporary root canal filling. This medicament significantly increases pH and optimizes the treatment outcome. Its total removal before final obturation is very important. Otherwise it could affect the hermetic filling and respectively the endodontic success. Aim: To evaluate the most effective irrigation protocol of calcium hydroxide removal from root canals. Materials and methods: In this study 36 single root canal teeth were observed. They were randomly divided into three groups (n=10 each group according to the technique applied for calcium hydroxide removal - manual irrigation, irrigation and Revo-S rotary instrumentation; and passive ultrasonic irrigation, and a control group (n=6 – irrigation with distilled water only. After calcium hydroxide removals following the procedures above, teeth were separated longitudinally in a buccal-lingual direction and remnants of medicaments were observed in the apical, middle and coronal part of each tooth. Then all of the specimens were observed using scanning electron microscopy and evaluated by a specified scale. The results have undergone statistical analysis. Results: In the case of calcium hydroxide in the apex and in the middle with highest average is Revo-S, followed by Ultrasonic and irrigation. In the coronal part the highest average belongs to Revo-S, irrigation and Ultrasonic. In all groups the highest average is represented by control group. Conclusion: There is not a universal technique for removal of intracanal medicaments and applying more than one protocol is required.

  10. Impacts of Irrigation and Drought on Salem Ground Water

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-06-01

    Full Text Available This investigation is the first of three phases of a ground-water management study. In this report, effects of irrigation and drought on the ground-water resources of Salem are examined. Irrigation water use for five soil types is estimated from a monthly water budget model on the basis of precipitation and temperature data from the last 30 years at selected weather stations across Salem. Moisture deficits are computed for each soil type on the basis of the water requirements of a corn crop. It is assumed that irrigation is used to make up the moisture deficit in those places where irrigation systems already exist. Irrigation water use from each township with irrigated acreage is added to municipal and industrial ground-water use data and then compared to aquifer potential yields. The spatial analysis is accomplished with a statewide geographic information system. An important distinction is made between the seasonal effects of irrigation water use and the annual or long-term effects.

  11. Wastewater Irrigation: Persistent Organic Pollutans in Soil and Product

    Directory of Open Access Journals (Sweden)

    Mehmet Emin AYDIN

    2015-06-01

    Full Text Available Treated or untreated wastewaters, used for irrigation purpose, contain various persistent organic pollutants. The long use of these waters for irrigation purpose results in deposition of the pollutants in soil, contaminates products and has adverse health affect on the human through food chain, and biologic activity of flora and fauna. The wastewaters of Konya were conveyed to the Salt Lake through the main drainage channel without any treatment until 2010.  During the arid period, the wastewater in the main drainage channel was used for irrigation and the products were cultivated. In this work, persistent organic pollutants i.e., polychlorinated biphenyls (PCB 28, 52, 101, 138, 153, 180 and polycyclic aromatic hydrocarbons (naphthalene, acenaphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene are determined in wastewater irrigated agricultural soil samples and the wheat samples cultivated in the region. High alkaline properties and clay structure of Konya soil were determined. These properties of soil result in the accumulation of contaminants in top soil layer used for agricultural production. On the other hand, PCB and PAH compounds were determined in comparable concentrations in well water irrigated reference soils with wastewater irrigated soils. PCB and PAH sources other than wastewater irrigation was evidenced for the study field.

  12. [Optimal allocation of irrigation water resources based on systematical strategy].

    Science.gov (United States)

    Cheng, Shuai; Zhang, Shu-qing

    2015-01-01

    With the development of the society and economy, as well as the rapid increase of population, more and more water is needed by human, which intensified the shortage of water resources. The scarcity of water resources and growing competition of water in different water use sectors reduce water availability for irrigation, so it is significant to plan and manage irrigation water resources scientifically and reasonably for improving water use efficiency (WUE) and ensuring food security. Many investigations indicate that WUE can be increased by optimization of water use. However, present studies focused primarily on a particular aspect or scale, which lack systematic analysis on the problem of irrigation water allocation. By summarizing previous related studies, especially those based on intelligent algorithms, this article proposed a multi-level, multi-scale framework for allocating irrigation water, and illustrated the basic theory of each component of the framework. Systematical strategy of optimal irrigation water allocation can not only control the total volume of irrigation water on the time scale, but also reduce water loss on the spatial scale. It could provide scientific basis and technical support for improving the irrigation water management level and ensuring the food security.

  13. Study on Intermittent Irrigation for Paddy Rice: II. Crop Responses

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effect of intermittent irrigation on the production of paddy rice was studied in a well-puddled paddy field with four treatments and 2 replicates: continuous flooding irrigation (CFI), and intermittent irrigation II-0, II-1 and II-2, in which plants were re-irrigated when the soil water potential fell below 0, -10, and -20 kPa, respectively, at soil depth of about 5 cm. Results showed that the reduction in soil water potential to about -10 or -20 kPa did not significantly affect the number of grains and the percentage of ripened grains. While, a lower crop growth rate (CGR) resulted from a decrease in the net assimilation rate (NAR) during intermittent irrigation II-1 and II-2, and there was also a reduction in the leaf area index (LAI) during intermittent irrigation II-2. Senescence of lower leaves on stems was promoted in treatments II-1 and II-2 at the ripening stage. Early senescence at ripening stage and water stress around midday decreased the rate of photosynthesis in leaves, causing the lower NAR. These physiological responses of the plants were responsible for the reduction in the dry matter production and grain yield in the intermittent irrigation treatments.

  14. Ocean-atmosphere interactions modulate irrigation's climate impacts

    Science.gov (United States)

    Krakauer, Nir Y.; Puma, Michael J.; Cook, Benjamin I.; Gentine, Pierre; Nazarenko, Larissa

    2016-11-01

    Numerous studies have focused on the local and regional climate effects of irrigated agriculture and other land cover and land use change (LCLUC) phenomena, but there are few studies on the role of ocean-atmosphere interaction in modulating irrigation climate impacts. Here, we compare simulations with and without interactive sea surface temperatures of the equilibrium effect on climate of contemporary (year 2000) irrigation geographic extent and intensity. We find that ocean-atmosphere interaction does impact the magnitude of global-mean and spatially varying climate impacts, greatly increasing their global reach. Local climate effects in the irrigated regions remain broadly similar, while non-local effects, particularly over the oceans, tend to be larger. The interaction amplifies irrigation-driven standing wave patterns in the tropics and midlatitudes in our simulations, approximately doubling the global-mean amplitude of surface temperature changes due to irrigation. The fractions of global area experiencing significant annual-mean surface air temperature and precipitation change also approximately double with ocean-atmosphere interaction. Subject to confirmation with other models, these findings imply that LCLUC is an important contributor to climate change even in remote areas such as the Southern Ocean, and that attribution studies should include interactive oceans and need to consider LCLUC, including irrigation, as a truly global forcing that affects climate and the water cycle over ocean as well as land areas.

  15. Comparison of final irrigation techniques in removal of calcium hydroxide.

    Science.gov (United States)

    Yücel, Ali Çağın; Gürel, Melek; Güler, Eda; Karabucak, Bekir

    2013-12-01

    The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter-appointment calcium hydroxide [Ca(OH)2 ]. Forty-seven extracted human single-rooted teeth were instrumented, and Ca(OH)2 paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30-gauge slot-tipped needle, EndoVac system and ProUltra® PiezoFlow™ ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5-grade scale. The influence of the irrigation system was evaluated using a two-way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores (P ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls. © 2011 The Authors. Australian Endodontic Journal © 2011 Australian Society of Endodontology.

  16. Decision support system for economic value of irrigation water

    Science.gov (United States)

    El-Gafy, Inas; El-Ganzori, Akram

    2012-06-01

    The mismatch between the supply and demand, inequitable distribution and the over irrigation of water consuming crops are the main constraints that are faced in the implementation of the integrated water resources management in Egypt. With water scarcity, the problem under consideration is that the current cropping pattern is not economically efficient in the utilization of the available water resource. Moreover, in consequence of the importance of the agricultural sector to the national economies, it is necessary to be aware of the economic performance of water use in the crops production. The scope of this study is to develop economic value of irrigation water maps of Egypt. The objective of the study is carried out by acquiring a Decision Support System for economic value of irrigation water of Egypt. This Decision Support System is applied for developing economic value maps for the irrigation water that is used for cultivating 45 crops under cereal, fiber, legumes, and vegetables, herbalist, and forages categories at each governorate of Egypt in year 2008 and 2009. The crops that achieve the highest and lowest economic value of irrigation water at each governorate of Egypt were identified. The reasons of the variations in the economic value of irrigation water at the governorates of Egypt were determined. The developed Decision Support System could be used yearly as a tool for demonstrating a picture about the economic value of irrigation water for the decision makers in the areas of water resources and agriculture. The developed economic value of irrigation water maps can be used in proposing a cropping pattern that maximizes the economic value of irrigation water in each governorate of Egypt.

  17. Estimating soil wetting patterns for drip irrigation using genetic programming

    Energy Technology Data Exchange (ETDEWEB)

    Samadianfard, S.; Sadraddini, A. A.; Nazemi, A. H.; Provenzano, G.; Kisi, O.

    2012-07-01

    Drip irrigation is considered as one of the most efficient irrigation systems. Knowledge of the soil wetted perimeter arising from infiltration of water from drippers is important in the design and management of efficient irrigation systems. To this aim, numerical models can represent a powerful tool to analyze the evolution of the wetting pattern during irrigation, in order to explore drip irrigation management strategies, to set up the duration of irrigation, and finally to optimize water use efficiency. This paper examines the potential of genetic programming (GP) in simulating wetting patterns of drip irrigation. First by considering 12 different soil textures of USDA-SCS soil texture triangle, different emitter discharge and duration of irrigation, soil wetting patterns have been simulated by using HYDRUS 2D software. Then using the calculated values of depth and radius of wetting pattern as target outputs, two different GP models have been considered. Finally, the capability of GP for simulating wetting patterns was analyzed using some values of data set that were not used in training. Results showed that the GP method had good agreement with results of HYDRUS 2D software in the case of considering full set of operators with R{sup 2} of 0.99 and 0.99 and root mean squared error of 2.88 and 4.94 in estimation of radius and depth of wetting patterns, respectively. Also, field experimental results in a sandy loam soil with emitter discharge of 4 L h{sup -}1 showed reasonable agreement with GP results. As a conclusion, the results of the study demonstrate the usefulness of the GP method for estimating wetting patterns of drip irrigation. (Author) 40 refs.

  18. Irrigation water quality as indicator of sustainable rural development

    Directory of Open Access Journals (Sweden)

    Trajković Slaviša

    2004-01-01

    Full Text Available The sustainable rural development more and more depends on the efficient usage of water resources. Most often, at least in one part of the year, the rain is not sufficient for plant growth and rain plant production significantly depends on the yearly precipitation variation. The increase and stability of the agricultural production is possible in the irrigation conditions. The most part (around 70% of the global water resources is used for food production. Irrigation water quality indicator is used to show if the available water resources have the required quality for application in agriculture. Irrigation is characterised by the complex water-plant-soil relationship, and in that eco-system the man as the end user of the irrigated fields occupies a very important place. That explains the difficulties in producing one universal classification of irrigation water quality. The paper analyses numerous water quality classifications from the aspect of the applicability on the quantifying of this indicator. The adopted classification should possess understandable, qualified and internationally comparable indicator. Thus, local classifications (Neigebauer, Miljkovic cannot be used for this indicator. United Nation Food and Agricultural Organization (FAO and US Salinity Laboratory (USSL classifications are used for the evaluation of the irrigation water quality throughout the world. FAO classification gives the complex picture of the usability of the irrigation water from the point of its influence on the soil and the plants. However, the scope of the analyses is not often suited to the needs of that classification, which makes it difficult to apply. The conclusion is that the USSL (US Salinity Laboratory classification is best suited to this range of chemical water analyses. The evaluation of the irrigation water quality indicator in the Juzna Morava river basin, upstream from the Toplica river estuary is given in this paper. Based on the obtained

  19. Uncertainties in modelling the climate impact of irrigation

    Science.gov (United States)

    de Vrese, Philipp; Hagemann, Stefan

    2017-04-01

    Many issues related to the climate impact of irrigation are addressed in studies that apply a wide range of models. These involve uncertainties related to differences in the model's general structure and parametrizations on the one hand and the need for simplifying assumptions with respect to the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In several simulations, we varied certain irrigation characteristics to estimate the resulting variations in irrigation's climate impact and found a large sensitivity with respect to the irrigation effectiveness. Here, the assumed effectiveness of the scheme is a combination of the target soil moisture and the degree to which water losses are accounted for. In general, the simulated impact of irrigation on the state of the land surface and the atmosphere is more than three times larger when assuming a low irrigation effectiveness compared to a high effectiveness. In an additional set of simulations, we varied certain aspects of the model's general structure, namely the land-surface-atmosphere coupling, to estimate the related uncertainties. Here we compared the impact of irrigation between simulations using a parameter aggregation, a simple flux aggregation scheme and a coupling scheme that also accounts for spatial heterogeneity within the lowest layers of the atmosphere. It was found that changes in the land-surface-atmosphere coupling do not only affect the magnitude of climate impacts but they can even affect the direction of the impacts.

  20. The importance of timing of precipitation for irrigation scheduling

    Science.gov (United States)

    Franz, T.; Hunt, E. D.; Wardlow, B.

    2016-12-01

    Irrigated agriculture, like rainfed agriculture, continues to serve an important role in the production of cereal crops, with increasing importance in the developing world. Many areas however, including the U.S. High Plains region, are faced with the daunting task of increasing crop production with less water, as groundwater reserves become further depleted. Climate change could further exacerbate limited supplies of groundwater in these regions. Thus, monitoring soil moisture under cereal crops is critical for determining the best irrigation strategies. The results obtained during an eight-year period from an irrigated field in eastern Nebraska demonstrated the importance of the timing of precipitation and soil moisture response for irrigation scheduling. The years with the fewest irrigation applications for both maize and soybeans were not the wettest years during the study period. Paradoxically, the year with the fewest irrigation treatments when soybeans were the common crop at the irrigated field and a nearby rainfed field was in 2006, which had below average growing season precipitation. The year with the most irrigation treatments (2008) when soybeans were also the common crop occurred during one of the wettest growing seasons over the past 30 years at Mead. The primary difference between the below average 2006 growing season and the wet 2008 growing season was that precipitation fell at regular intervals during critical reproductive stages for soybeans in 2006 keeping the soil profile moist. Conversely, the only dry spell of the 2008 growing season occurred during that same critical period, thus necessitating irrigation applications that prevented depletion of soil profile.

  1. Water Management For Drip Irrigated Corn In The Arid Southeastern Anatolia Project Area In Turkey

    Science.gov (United States)

    Yazar, A.; Gencel, B.

    Microirrigation has the potential to minimize application losses to evaporation, runoff and deep percolation; improve irrigation control with smaller, frequent applications; supply nutrients to the crop as needed; and improve crop yields. The Southeastern Anatolia Project (GAP), when completed, 1.7 million ha of land will be irrigated. Wa- ter supplies are limited, and traditional irrigation practices result in high losses and low irrigation efficiences. This study was conducted to evaluate surface drip irrigation on crop performance. The effect of irrigation frequency and amount on crop yield, yield components, water use, and water use efficiency of corn (Zea mays L., PIO- 3267) were investigated in the Harran Plain in the arid Southeastern Turkey on a clay textured Harran Soil Series. Irrigation frequencies were once in three-day, and once in six-day; irrigation levels varied from full (I-100), medium (I-67; 2/3rd of full), and low (I-33; 1/3rd of full). The full irrigation treatment received 100% of the cumula- tive evaporation within the irrigation interval. Liquid nitrogen was injected into the irrigation water throughout the growing season. Treatments received the same amount of fertilizers. Highest average corn grain yield (11920 kg/ha) was obtained from the full irrigation treatment (I-100) with six-day irrigation interval. Irrigation intervals did not affect corn yields; however, deficit irrigation affected crop yields by reducing seed mass, and the seed number. Maximum water use efficiency (WUE) was found as 2.27 kg/m3 in the I-33 treatment plots with three-day irrigation interval. On the clay soil at Harran, irrigation frequencies are less critical than proper irrigation management for drip irrigation systems to avoid water deficits that have a greater effect on corn yields. The results revealed that about 40% water saving is possible with drip irrigation as compared to traditional surface irrigation methods in the region.

  2. Changes of soil organic matter and microbial activity in irrigated and non irrigated olive groves

    Science.gov (United States)

    Kavvadias, Victor; Papadopoulou, Maria; Theocharopoulos, Sideris; Vavoulidou, Evagelia; Doula, Maria; Reppas, Spiros

    2014-05-01

    The implementation of olive cultivation techniques in Greece has not been systematically tested under the prevailing Mediterranean conditions. A LIFE+ project was initiated (oLIVE-CLIMA; LIFE 11/ENV/000942) aiming to introduce new management practices in olive tree crops that lead to increased carbon dioxide uptake by plants as well as carbon sequestration from the atmosphere and reverse the trend of soil organic matter decline, erosion and desertification. This paper presents data on soil organic matter and microbial activity from a soil campaign in a pilot region in Greece, and particularly in the area of Chora, prefecture of Messinia, South west Peloponnese. The soil campaign took place during the period December 2012-February 2013. Twelve soil parcels of olive groves were selected (6 irrigated and 6 rainfed) and in each soil parcel six composite soil samples were taken from 0-10 cm depth at equal intervals along a straight line of the trunk of the tree to the middle of the distance from the nearest tree of the next tree series. The first three samples were under olive tree canopy. An additional composite sample was taken at depth of 10-40 cm. Soil samples were analyzed for soil physicochemical and biological properties. In this study results for total organic carbon (TOC), soil basal microbial respiration (BR), microbial biomass C (MB-C) from the region of Messinia, are presented. Organic matter was determined by dichromate oxidation. The microbial activity was measured by the amount of CO2 evolution, while microbial biomass C was determined by substrate-induced respiration, after the addition of glucose. The results showed considerable differences in TOC, BR and MB-C associated with the sampling position and soil depth. The higher TOC, BR and MB-C values, in most cases, were determined in samples taken from points under the canopy, but not close to the tree trunk compared to the sampling points outside the canopy. This indicates the positive effect of

  3. Climate change and irrigation demand: Uncertainty and adaptation

    Directory of Open Access Journals (Sweden)

    Sean A. Woznicki

    2015-03-01

    New hydrological insights for the region: Uncertainty in irrigation demand was found to increase moving from 2020–2039 to 2060–2079, with demand generally decreasing moving further into the future for corn and soybean. A shift in timing of peak irrigation demand and increases in temperature lead to corn yield reductions. However, soybean yield increased under these conditions. Finally, the adaptation strategy of planting earlier increased irrigation demand and water available for transpiration, while delaying planting resulted in demand decreases for both crops.

  4. Irrigation management using an expert system, soil water potentials, and vegetative indices for spatial applications

    Science.gov (United States)

    Variable rate irrigation (VRI) systems are irrigation systems that are capable of applying different water depths both in the direction of travel and along the length of the irrigation system. However, when compared to traditional irrigation systems, VRI systems require a higher level of management...

  5. Alternate partial root-zone drying irrigation improves fruit quality in tomatoes

    DEFF Research Database (Denmark)

    Sun, Y.; Holm, Peter Engelund; Liu, Fulai

    2014-01-01

    Alternate partial root-zone drying (PRD) irrigation and deficit irrigation (DI) are water-saving irrigation strategies. Here, comparative effects of PRD and DI on fruit quality of tomato (Solanum lycopersicum L.) were investigated. The results showed that the irrigation treatments had no effect...

  6. Irrigation Scheduling for Green Bell Peppers Using Capacitance Soil Moisture Sensors

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Femminella, K.; Munoz-Carpena, R.

    2011-01-01

    Vegetable production areas are intensively managed with high inputs of fertilizer and irrigation. The objectives of this study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling using soil moisture sensor irrigation controllers (SMS) on yield, irrigation water use

  7. The phenology of malaria mosquitos in irrigated rice fields in Mali

    NARCIS (Netherlands)

    Klinkenberg, E.; Takken, W.; Huibers, F.P.; Touré, Y.T.

    2003-01-01

    A field study was carried out in the large-scale rice irrigation scheme of the Office du Niger in Mali to investigate the relation between anopheline mosquito larval development and small-scale differences in irrigation practices, such as water level, irrigation application and irrigation frequency.

  8. Estimation of furrow irrigation sediment loss using an artificial neural network

    Science.gov (United States)

    The area irrigated by furrow irrigation in the U.S. has been steadily decreasing but still represents about 20% of the total irrigated area in the U.S. Furrow irrigation sediment loss is a major water quality issue and a method for estimating sediment loss is needed to quantify the environmental imp...

  9. 25 CFR 171.410 - Can I install a fence on a BIA irrigation project?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I install a fence on a BIA irrigation project? 171... IRRIGATION OPERATION AND MAINTENANCE Irrigation Facilities § 171.410 Can I install a fence on a BIA irrigation project? Yes. Fences are considered structures and may be installed in compliance with § 171.405....

  10. Alternate partial root-zone drying irrigation improves fruit quality in tomatoes

    DEFF Research Database (Denmark)

    Sun, Y.; Holm, Peter Engelund; Liu, Fulai

    2014-01-01

    Alternate partial root-zone drying (PRD) irrigation and deficit irrigation (DI) are water-saving irrigation strategies. Here, comparative effects of PRD and DI on fruit quality of tomato (Solanum lycopersicum L.) were investigated. The results showed that the irrigation treatments had no effect...

  11. 25 CFR 171.210 - Where will BIA provide my irrigation service?

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Where will BIA provide my irrigation service? 171.210 Section 171.210 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.210 Where will BIA provide my irrigation service? (a)...

  12. Irrigation Scheduling for Green Bell Peppers Using Capacitance Soil Moisture Sensors

    NARCIS (Netherlands)

    Zotarelli, L.; Dukes, M.D.; Scholberg, J.M.S.; Femminella, K.; Munoz-Carpena, R.

    2011-01-01

    Vegetable production areas are intensively managed with high inputs of fertilizer and irrigation. The objectives of this study were to evaluate the interaction between N-fertilizer rates and irrigation scheduling using soil moisture sensor irrigation controllers (SMS) on yield, irrigation water use

  13. Optimization of irrigation water in stone fruit and table grapes

    Science.gov (United States)

    de la Rosa, Jose Mª; Castillo, Cristina; Temnani, Abdel; Pérez-Pastor, Alejandro

    2017-04-01

    In water scarcity areas, it must be highlighted that the maximum productions of the crops do not necessarily imply maximum profitability. Therefore, during the last years a special interest in the development of deficit irrigation strategies based on significant reductions of the seasonal ET without affecting production or quality has been observed. The strategies of regulated deficit irrigation (RDI) are based on the reduction of water supply during non critical periods, the covering of water needs during critical periods and maximizing, at the same time, the production by unit of applied water. The main objective of this experiment was to implement, demonstrate and disseminate a sustainable irrigation strategy based on deficit irrigation to promote its large scale acceptance and use in woody crops in Mediterranean agroecosystems, characterized by water scarcity, without affecting the quality standards demanded by exportation markets. Five demonstration plots were established in representative crops of the irrigating community of Campotejar (Murcia, Spain): i) Peach trees, cv. catherina in the "Periquitos" farm; ii) Apricot trees, cv. "Red Carlet" in "La Hoya del Fenazar" farm; iii) Nectarine trees, cv. Viowhite in "Agrícola Don Fernando" farm; iv) Table grape, cv "Crimson Seedless" in "La Hornera" farm; and v) Paraguayan cv. carioca in "The Hornera" farm. In each demonstration plot, at least two irrigation treatments were established: i) Control (CTL), irrigated to ensure non-limiting water conditions (120% of crop evapotranspiration) and ii) Regulated deficit irrigation (RDI) irrigated as CTL during critical periods and decreasing irrigation in non-critical periods. The plant water status indicators evaluated were midday stem water potential and Trunk Diameter Fluctuation derived indices: maximum daily shrinkage (MDS) and trunk daily growth rate (TGR); vegetative growth of the different crops from trunk diameter and pruning dry weight, fruit growth and fruit

  14. Corelation between Machines Assisted Endodontic Irrigant Agitation and Apical Extrusion of Debris and Irrigant: A Laboratory Study

    Directory of Open Access Journals (Sweden)

    Jatin Gupta

    2014-01-01

    Full Text Available Aims. To compare amount of root canal debris and irrigant extruded apically after irrigants agitation using closed and open chambers. Methods and Material. Sixty maxillary central incisors were selected, decoronated, and mounted in preweighed glass vials filled with distilled water. Biomechanical preparation was completed using ProTaper rotary files until number F4 and 1 mL of 3% NaOCl solution after each file use. Samples were randomly divided into closed or open chamber sets which were further subdivided into 6 groups, based on the agitation techniques: no agitation (control, canalBrush, lentulospiral, passive ultrasonic agitation (PUA, EndoActivator, and EndoVac. Canals were irrigated with 1 mL of 17% EDTA and agitated for 30 s and then flushed with 2 mL of distilled water. Apically extruded irrigant was measured and vials were kept in incubator for 5 days at 68°C for drying for weight calculation. Statistical Analysis. Analysis was done using Student’s t-test, one-way ANOVA, and post-hoc. Results. All agitation techniques showed apical extrusion of the debris and irrigant. The closed chamber apparatus showed significantly less extrusion of debris and irrigant than open chamber (P<0.05. Conclusions. EndoVac was found to be the safest agitation system among all test groups with regard to apical extrusion of debris and irrigant.

  15. Effects of drip irrigation under plastic film with saline water on cotton growth and yields

    Science.gov (United States)

    Wang, B.; Jin, M.; He, Y.; Zhou, J.; Brusseau, M. L.

    2012-12-01

    To study the influence of different irrigation system for drip irrigation under plastic film with saline water on cotton growth and yields, field experiments at key irrigation experiment station of water resources management division in Bayingolin Mongol Autonomous Prefecture, Xinjiang, China were set up consist of different irrigation ratio (5250, 4500, 3750, 3000m3/hm2), different irrigation times (24, 12 and 8 times) and different rotation irrigation modes. The results show that: with the larger irrigation ratio, the cotton growth and yields was also better, and the significant influence on cotton growth and yields for irrigation ratio is between 3750-4500 m3/hm2. When the irrigation ratio is smaller (3000m3/hm2), cotton growth and yields for irrigation times of 8 times are higher, When the irrigation ratio is bigger (4500m3/hm2), cotton growth for irrigation times of 12 times are better and its cotton yields are higher correspondingly. According to the growth of cotton, yields and water productivity, the suitable irrigation system of cotton is the irrigation ratio of 4500-3750 m3/ hm2 and the irrigation times of 18 times for drip irrigation under plastic film with saline water. For different rotation drip irrigation experiments with saline water and fresh water, the cotton yields and irrigation water productivity is higher under the disposal of SF (rotation irrigation in first 6 times with saline water irrigation and then 6 times with fresh water irrigation) compared to FS (rotation irrigation in first 6 times with fresh water and then 6 times with saline water) and SSFA (rotation irrigation with twice saline water and once fresh water) compared to SFA (alternative irrigation with saline water and fresh water). Compared to the different alternate irrigation experiments, the cotton yields and water productivity for pure saline water irrigation is higher. In addition, the trend is the larger the irrigation ratio and the higher the yields. It maybe dues to the low

  16. Microeconomics of Deficit Irrigation and Subjective Water Response Function for Intensive Olive Groves

    Directory of Open Access Journals (Sweden)

    Alfonso Expósito

    2016-06-01

    Full Text Available This research paper analyzes the economics of deficit irrigation based on the use of subjective estimates of the crop yield–water relationship to determine water supply in irrigated olive groves. Interviewed farmers were asked to give three estimates for the yield-water relationship as a function of water supply (full irrigation, usual deficit irrigation and extreme deficit irrigation. Those responses are contrasted with the actual irrigation dose and the results appear to support the hypothesis that a majority of farmers use deficit irrigation as a strategy that maximizes the value of limited water input rather than the conventional microeconomic behavior of maximizing the return to land.

  17. Comparison of hydrogen sulfide removal using bio-trickling filters by inoculating sulfur-oxidizing bacteria and activated sludge%接种辫硫杆菌与活性污泥生物滴滤塔去除硫化氢效果对比

    Institute of Scientific and Technical Information of China (English)

    张兰河; 宋达; 杨日光; 张德义

    2013-01-01

    The deodorization experiment of hydrogen sulfide(H2S)was carried out continuously using bio-trickling filter A inoculating sulfur-oxidizing bacteria and bio-trickling filter B inoculating activated sludge in order to solve the odor pollution. The two bioreactors were operated for more than four months to investigate the effects of inlet concentration,shock loading and consuming quantity of nitrogen on the removal efficiency of H2S. Pressure drops of the bio-trickling filters were also compared before and after the experiment. The results suggested that removal efficiency of the bio-trickling filter A was nearly 100%when inlet concentration of H2S was lower than 600 mg/m3 and the corresponding inlet loading was lower than 113.33 g/(m3·h). Removal efficiency of the bio-trickling filter B was nearly 100% when inlet concentration of H2S was lower than 750 mg/m3 and the corresponding inlet loading was lower than 133.33 g/(m3·h). Pressure drops of the bio-trickling filter A and B were respectively 176.4 Pa/m and 313.6 Pa/m at 8 m3/h of gas flow rate. Compared with bio-trickling filter A,the bio-trickling filter B performed a relatively rapid startup,relatively high removal efficiency and ability to resist shock-loading. However,the bio-trickling filter B had a relatively high pressure drop and its removal efficiency was easily influenced by nitrogen source.%  为了解决恶臭污染问题,采用接种辫硫杆菌ZG11的生物滴滤塔A与接种活性污泥的生物滴滤塔B对硫化氢气体进行了4个多月的脱臭实验研究,主要考察了进气浓度、冲击负荷和氮利用率对硫化氢去除率的影响以及实验前后压力损失的变化。结果表明:当硫化氢进气浓度低于600 mg/m3,即进气负荷Nv低于113.33 g/(m3·h)时,滴滤塔A的去除率接近100%。当进气浓度低于750 mg/m3,即Nv低于133.33 g/(m3·h)时,滴滤塔B的去除率接近100%。当进气流量为8 m3/h时,滴滤塔A

  18. An assessment of global net irrigation water requirements from various water supply sources to sustain irrigation: rivers and reservoirs (1960–2000 and 2050

    Directory of Open Access Journals (Sweden)

    A. Khajuria

    2013-01-01

    Full Text Available Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependency of the supply of irrigation water from rivers, large reservoirs with a greater than 1.0 km3 storage capacity, medium-size reservoirs with storage capacities ranging from 1.0 km3 to 3.0 Mm3, and non-local non-renewable blue water (NNBW, particularly taking into account variations in irrigation area during the period 1960–2000. We also estimated the future irrigation water requirements from water supply sources in addition to these four sources, using an irrigation area scenario. The net irrigation water requirements from various supply sources were assessed using the global H08 water resources model. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0°. We obtained net irrigation water from rivers and medium-size reservoirs, and determined that the NNBW increased continuously from 1960 to 1985, but the net irrigation water from large reservoirs increased only marginally. After 1985, the net irrigation water from rivers approached a critical limit with the continued expansion of the irrigation area. The irrigation water requirements from medium-size reservoirs and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of medium-size reservoirs. Under the irrigation area scenario without climate change, global net irrigation water requirements from additional water supply sources will account for 26% of the total requirements in the year 2050. We found that expansion of irrigation areas due to population growth will generate an enormous demand for irrigation water from additional resources.

  19. An assessment of global net irrigation water requirements from various water supply sources to sustain irrigation: rivers and reservoirs (1960-2000 and 2050)

    Science.gov (United States)

    Yoshikawa, S.; Cho, J.; Yamada, H. G.; Hanasaki, N.; Khajuria, A.; Kanae, S.

    2013-01-01

    Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependency of the supply of irrigation water from rivers, large reservoirs with a greater than 1.0 km3 storage capacity, medium-size reservoirs with storage capacities ranging from 1.0 km3 to 3.0 Mm3, and non-local non-renewable blue water (NNBW), particularly taking into account variations in irrigation area during the period 1960-2000. We also estimated the future irrigation water requirements from water supply sources in addition to these four sources, using an irrigation area scenario. The net irrigation water requirements from various supply sources were assessed using the global H08 water resources model. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0°. We obtained net irrigation water from rivers and medium-size reservoirs, and determined that the NNBW increased continuously from 1960 to 1985, but the net irrigation water from large reservoirs increased only marginally. After 1985, the net irrigation water from rivers approached a critical limit with the continued expansion of the irrigation area. The irrigation water requirements from medium-size reservoirs and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of medium-size reservoirs. Under the irrigation area scenario without climate change, global net irrigation water requirements from additional water supply sources will account for 26% of the total requirements in the year 2050. We found that expansion of irrigation areas due to population growth will generate an enormous demand for irrigation water from additional resources.

  20. Assessing the Efficacy of the SWAT Auto-Irrigation Function to Simulate Irrigation, Evapotranspiration, and Crop Response to Management Strategies of the Texas High Plains

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2017-07-01

    Full Text Available In the semi-arid Texas High Plains, the underlying Ogallala Aquifer is experiencing continuing decline due to long-term pumping for irrigation with limited recharge. Accurate simulation of irrigation and other associated water balance components are critical for meaningful evaluation of the effects of irrigation management strategies. Modelers often employ auto-irrigation functions within models such as the Soil and Water Assessment Tool (SWAT. However, some studies have raised concerns as to whether the function is able to adequately simulate representative irrigation practices. In this study, observations of climate, irrigation, evapotranspiration (ET, leaf area index (LAI, and crop yield derived from an irrigated lysimeter field at the USDA-ARS Conservation and Production Research Laboratory at Bushland, Texas were used to evaluate the efficacy of the SWAT auto-irrigation functions. Results indicated good agreement between simulated and observed daily ET during both model calibration (2001–2005 and validation (2006–2010 periods for the baseline scenario (Nash-Sutcliffe efficiency; NSE ≥ 0.80. The auto-irrigation scenarios resulted in reasonable ET simulations under all the thresholds of soil water deficit (SWD triggers as indicated by NSE values > 0.5. However, the auto-irrigation function did not adequately represent field practices, due to the continuation of irrigation after crop maturity and excessive irrigation when SWD triggers were less than the static irrigation amount.

  1. Possible Impacts of Future Climate Change on Irrigated Winter Wheat and Adaptive Strategies in Henan Province%气候变化对河南省灌溉小麦的影响及对策初探

    Institute of Scientific and Technical Information of China (English)

    成林; 刘荣花; 王信理

    2012-01-01

    , respectively. Results show that postponing the planting date has an effect on increasing yield and yield stability,subtracting the planting density to some extent achieves more yield than increasing the density, and changing the watering method from ditch irrigation to trickle could save water resource and enhance final yield.%灌溉是河南省冬小麦最重要的种植管理模式.在DSSAT-CERES小麦模型参数调试和区域适用性验证的基础上,利用区域气候模式PRECIS输出的未来气候情景资料,量化分析了2021-2050年河南省灌溉条件下冬小麦产量的可能变化,结果表明:若不采取其他措施,未来A2,B2两种温室气体排放情景下,河南省冬小麦产量平均减少5%左右,A2情景减产率略高于B2;随着产量降低,产量波动区间略有缩小,但25%~75%的稳产区间也相应缩小,且B2情景下更容易出现极端低产的年份;冬小麦水分利用效率相应降低.采取适当应对措施,如延迟播种期、减小种植密度等有利于提高产量或缓解减产趋势.

  2. Comparative effects of partial root-zone irrigation and deficit irrigation on phosphorus uptake in tomato plants

    DEFF Research Database (Denmark)

    Wang, Yaosheng; Liu, Fulai; Jensen, Christian Richardt

    2012-01-01

    The comparative effects of partial root-zone irrigation (PRI) and deficit irrigation (DI) on phosphorus (P) uptake in tomato (Lycopersicon esculentum Mill.) plants were investigated in a split-root pot experiment. The results showed that PRI treatment improved water-use efficiency (WUE) compared...... mineral N fertilisation, while similar physiological and agronomic P-use efficiencies were found between the two irrigation treatments with organic N fertilisation. PRI-induced drying and wetting processes might have influenced the bio-availability of soil P, as the concentrations of bio-available P...

  3. A comparison of malaria prevalence, control and management strategies in irrigated and non-irrigated areas in eastern Kenya.

    Science.gov (United States)

    Muriuki, John Muthii; Kitala, Philip; Muchemi, Gerald; Njeru, Ian; Karanja, Joan; Bett, Bernard

    2016-08-11

    This study was conducted in Bura irrigation scheme in Tana River County and the pastoral area in Ijara, Garissa County in the eastern Kenya to establish the knowledge, attitude and practices on malaria transmission, control and management, and determine malaria prevalence and the associated risk factors. A cross sectional survey design that involved 493 randomly selected people from 334 households was used between November and December 2013. All the randomly selected people were screened for malaria parasites using rapid diagnostic test (RDT)-Carestart™ malaria HRP2 (pf) kit. A questionnaire was administered to determine potential risk factors and perceptions on malaria exposure within a period of 2 months prior to the survey. Two logistic regression models were fitted to the data; one used the RDT results while the other used data from the questionnaire survey. Using RDT, the prevalence of malaria was 4.68 % (95 % CI: 1.48-7.88 %) and 0.31 % (-0.30 to 0.92 %) in irrigated and non-irrigated areas, respectively. From the questionnaires, 14.62 % (9.27-19.97 %) and 23.91 % (19.23-28.60 %) of the participants perceived to have had malaria in the irrigated and pastoral areas, respectively. The main malaria control measure was the use of bed nets: average of three nets per household in Bura irrigation scheme and one in Ijara. Artemether-lumefantrine was the main drug of choice mainly in the irrigated area while sulfadoxine-pyrimethamine was likely to be used in the non-irrigated area. Households located >5 km from the nearest health facility had higher prevalence of Plasmodium infection than those located ≤5 km. The residents of Bura irrigation scheme were more likely to be infected compared to those living in the non-irrigated area of Ijara. However, those in the non-irrigated area were more likely to be treated or use over-the-counter medication for perceived malaria illnesses compared to those in the irrigated area. There is a need, therefore, to

  4. Evaluation of an operational real-time irrigation scheduling scheme for drip irrigated citrus fields in Picassent, Spain

    Science.gov (United States)

    Li, Dazhi; Hendricks-Franssen, Harrie-Jan; Han, Xujun; Jiménez Bello, Miguel Angel; Martínez Alzamora, Fernando; Vereecken, Harry

    2017-04-01

    Irrigated agriculture accounts worldwide for 40% of food production and 70% of fresh water withdrawals. Irrigation scheduling aims to minimize water use while maintaining the agricultural production. In this study we were concerned with the real-time automatic control of irrigation, which calculates daily water allocation by combining information from soil moisture sensors and a land surface model. The combination of soil moisture measurements and predictions by the Community Land Model (CLM) using sequential data assimilation (DA) is a promising alternative to improve the estimate of soil and plant water status. The LETKF (Local Ensemble Transform Kalman Filter) was chosen to assimilate soil water content measured by FDR (Frequency Domain Reflectometry) into CLM and improve the initial (soil moisture) conditions for the next model run. In addition, predictions by the GFS (Global Forecast System) atmospheric simulation model were used as atmospheric input data for CLM to predict an ensemble of possible soil moisture evolutions for the next days. The difference between predicted and target soil water content is defined as the water deficit, and the irrigation amount was calculated by the integrated water deficit over the root zone. The corresponding irrigation time to apply the required water was introduced in SCADA (supervisory control and data acquisition system) for each citrus field. In total 6 fields were irrigated according our optimization approach including data assimilation (CLM-DA) and there were also 2 fields following the FAO (Food and Agriculture Organization) water balance method and 4 fields controlled by farmers as reference. During the real-time irrigation campaign in Valencia from July to October in 2015 and June to October in 2016, the applied irrigation amount, stem water potential and soil moisture content were recorded. The data indicated that 5% 20% less irrigation water was needed for the CLM-DA scheduled fields than for the other fields

  5. THE PILOT STUDYING OF DOMESTIC SEWAGE USING A NEW BIO-TRICKLING FILTER%新型生物滴滤池处理生活污水的中试研究

    Institute of Scientific and Technical Information of China (English)

    陈蒙亮; 王鹤立; 陈晓强

    2012-01-01

    The study was conducted using a new bio-trickling filter that combined filtration pattern and immersion pattern to treat sewage wastewater. The removal effect of COD、NH3-N、TN and TP were Investigated. The results showed that removal efficiency for COD and NH3-N and TP were 79.2%, 90.8% and 70.05% respectively. But the removal efficiency of TN was less than 20% . Contrasting traditional technology such as activated sludge process, high loading trickling filter etc in electrical energy consumption, energy consumption of new bio-filter didn't exceed by 22%.%试验研究采用滴滤模式与淹没模式相结合的新型滴滤池处理生活污水.考察了该装置对生活污水中COD、NH3-N、TN、TP污染物的去除效果.试验结果表明,该滤池对COD、NH3-N和TP有较好的去除效果,去除率分别达到79.2%、90.8%和70.05%,但对TN的去除率不超过20%.通过与传统活性污泥法、高负荷生物滴滤池等进行电能能耗对比,新型生物滤池电能消耗不超过22%.

  6. Root canal irrigants: a review of their interactions, benefits, and limitations.

    Science.gov (United States)

    Jena, Amit; Sahoo, Sanjit Kumar; Govind, Shashirekha

    2015-04-01

    Endodontic treatment success depends on a combination of appropriate instrumentation, effective irrigation and decontamination of root canal spaces to apices, and obturation of the root canals. Irrigation of the root canal is paramount in determining periapical tissue healing. This article reviews presently available root canal irrigants, their interactions, advantages, and limitations. For this review, the authors performed a Medline search for all English language articles published through January 2014 with "root canal irrigants" and "endodontic irrigants" as keywords.

  7. Drip irrigation: Will it increase yield in traditional vegetable production system?

    OpenAIRE

    Anas D Susila; T. Prasetyo

    2008-01-01

    In the rain-fed production system area, vegetables normally can be grown on wet season (>200 mm/month) between December - April. During dry season ( Drip irrigation systems have the highest potential water application efficiency of the irrigation system used in commercial vegetables production. Field studies have shown a significant decrease in irrigation requirements of tomatoes with the use of drip irrigation system and compared to sub-irrigation system. Marketable yield, fruit size, and fr...

  8. Draft environmental assessment : National Elk Refuge irrigation rehabilitation project

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Over an approximate 5-year period the National Elk Refuge is proposing to install a sprinkler irrigation system and implement farming practices on some of the...

  9. The effects of different irrigation protocols on removing calcium ...

    African Journals Online (AJOL)

    2015-11-02

    Nov 2, 2015 ... ... at all root thirds. Key words: Calcium hydroxide removal, irrigation solutions, ultrasonic activation .... Barium sulfate was added to the distilled water ... were dehydrated and coated with gold‑palladium particles. (20 nm) and ...

  10. Integrating Water Supply Constraints into Irrigated Agricultural Simulations of California

    Science.gov (United States)

    Winter, Jonathan M.; Young, Charles A.; Mehta, Vishal K.; Ruane, Alex C.; Azarderakhsh, Marzieh; Davitt, Aaron; McDonald, Kyle; Haden, Van R.; Rosenzweig, Cynthia E.

    2017-01-01

    Simulations of irrigated croplands generally lack key interactions between water demand from plants and water supply from irrigation systems. We coupled the Water Evaluation and Planning system (WEAP) and Decision Support System for Agrotechnology Transfer (DSSAT) to link regional water supplies and management with field-level water demand and crop growth. WEAP-DSSAT was deployed and evaluated over Yolo County in California for corn, rice, and wheat. WEAP-DSSAT is able to reproduce the results of DSSAT under well-watered conditions and reasonably simulate observed mean yields, but has difficulty capturing yield interannual variability. Constraining irrigation supply to surface water alone reduces yields for all three crops during the 1987-1992 drought. Corn yields are reduced proportionally with water allocation, rice yield reductions are more binary based on sufficient water for flooding, and wheat yields are least sensitive to irrigation constraints as winter wheat is grown during the wet season.

  11. Cavitation Measurement during Sonic and Ultrasonic Activated Irrigation

    NARCIS (Netherlands)

    Macedo, Ricardo; Verhaagen, Bram; Rivas, David Fernandez; Versluis, Michel; Wesselink, Paul; van der Sluis, Luc

    Introduction: The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. Methods: The amount of cavitation generated around several endodontic instruments was

  12. Farmers' Willingness to Pay for Private Irrigation Supply in Nandom ...

    African Journals Online (AJOL)

    2017-05-01

    May 1, 2017 ... Kuuder, (2013) examined how irrigation affects household food ... Model), the assumption that behaviour can be predicted by attitudes and intentions to ... goods, consumers are expected to purchase more as their incomes ...

  13. irrigated agriculture and poverty reduction in kassena nankana ...

    African Journals Online (AJOL)

    User

    2010-09-08

    Sep 8, 2010 ... and inadequate ready market to translate the outputs into improved incomes for the farmers. Actors in the irrigated .... develop a pricing system and a mechanism ..... The farmers mix combinations of insecticides and fungi-.

  14. Sustainable irrigation and nitrogen management of fertigated vegetable crops

    NARCIS (Netherlands)

    Thompson, R.B.; Incrocci, L.; Voogt, W.; Pardossi, A.; Magán, J.J.

    2017-01-01

    Fertigation in combination with drip irrigation is being increasingly used in vegetable crop production. From a nutrient management perspective, this combination provides the technical capacity for precise nitrogen (N) nutrition, both spatially and temporally. With these systems, N and other

  15. Enhanced Metal Levels in Vegetables and Farm Soil irrigated with ...

    African Journals Online (AJOL)

    Michael Horsfall

    water but Mn was higher in industrial waste water and soil irrigated with industrial waste water and treated water. Soil ... Karachi City. Government supplies the treated water (TW) for drinking. ..... Water manganese exposure and children's.

  16. Xylem Development of Loblolly Pine During Irrigation and Simulated Drought

    Science.gov (United States)

    David M. Moehring; Charles X. Grano; John R. Bassett

    1975-01-01

    Induced drought decreased the total number of tracheid cells produced in a season and the radial width of late wood tracheids. Transition from earlywood to late woodo ccurred in early June and was little affected by irrigation.

  17. Energy savings potential from energy-conserving irrigation systems

    Energy Technology Data Exchange (ETDEWEB)

    Wilfert, G.L.; Patton, W.P.; Harrer, B.J.; Clark, M.A.

    1982-11-01

    This report systematically compares, within a consistent framework, the technical and economic characteristics of energy-conserving irrigation systems with those of conventional irrigation systems and to determine total energy savings. Levelized annual costs of owning and operating both energy-conserving and conventional irrigation systems have been developed and compared for all 17 states to account for the differences in energy costs and irrigation conditions in each state. Market penetration of energy-conserving systems is assessed for those systems having lower levelized annual costs than conventional systems performing the same function. Annual energy savings were computed by matching the energy savings per system with an assumed maximum market penetration of 100 percent in those markets where the levelized annual costs of energy-conserving systems are lower than the levelized annual costs of conventional systems.

  18. Solar technology applications: a survey of solar powered irrigation systems

    Energy Technology Data Exchange (ETDEWEB)

    Newkirk, H.W.

    1978-04-17

    Published information on solar powered irrigation systems is presented. Thermal solar systems, thermoelectric solar systems, and photovoltaic solar systems are included. A bibliography and survey of on-going work is presented. (WHK)

  19. Multiplatform automated system for monitoring and sprinkler irrigation control

    Directory of Open Access Journals (Sweden)

    PINTO, M. L.

    2016-06-01

    Full Text Available The automation systems together with web and mobile control is a facilitator of the various processes in several areas, among them the agricultural sector. Specically in the irrigation management, the lowest cost technology is not able to satisfy the farmer's needs, which are the correct water supply to plants and remote monitoring of the irrigation. The objective of this paper is to present a system for controlling and monitoring irrigation with a multiplatform support for both desktop and web/mobile. The system is designed to realize automatic irrigation management in order to provide the exact amount of water needed for culture, avoiding water stress both the culture and the waste of resources such as water and electricity. Additionally, the system allows remote monitoring from anywhere by means of a computer and/or mobile device by internet. This work was developed during the undergraduate mentorship of the authors.

  20. Alterations in reducing sugar in Triticum aestivum under irrigated ...

    African Journals Online (AJOL)

    DELL

    2012-03-13

    Mar 13, 2012 ... There were thirteen wheat genotypes, two irrigation levels and two replications of each. .... other cellular component from the adverse effects of drought in a manner .... Sugar-induced signal transduction in plants. Ann. Rev.