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ABSTRACT A trickling irrigation system was installed in a cotton field to study the effects on the clogging of the emitters using treated wastewater. Also the effects of using reclaimed effluents on cotton yield and soil properties were... more
ABSTRACT A trickling irrigation system was installed in a cotton field to study the effects on the clogging of the emitters using treated wastewater. Also the effects of using reclaimed effluents on cotton yield and soil properties were studied under the the field conditions. In general the reduction in flow rate in the emitters along the lateral was linear. The changes in soil properties after irrigation with wastewater were found to be within an acceptable range. In response to the given amounts of water, the cotton yield was as expected. This showed that if larger amounts of water were applied under existing irrigation conditions, a higher yield per unit area could be obtained.
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Research Interests: Environmental Engineering, Environmental Science, Chemistry, Water, Wastewater Treatment, and 15 moreWaste Management, Multidisciplinary, First-Order Logic, Biomass production, First Order Logic, Sewage, Sewage Treatment, Effluent, CLIMATE CHANGE AND WATER RES, Boolean Satisfiability, Retention Time, Pilot Plant, Fecal Coliform, Fecal Coliforms, and UASB reactor
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ABSTRACT Trickle irrigation experiments with two qualities of mixtures of reservoir effluents and stormwater, were conducted in a 1-yr research project at two kibbutzim (communal farms) in the Jezreel Israel. Various Israel methods and... more
ABSTRACT Trickle irrigation experiments with two qualities of mixtures of reservoir effluents and stormwater, were conducted in a 1-yr research project at two kibbutzim (communal farms) in the Jezreel Israel. Various Israel methods and degrees of filtration were examined and then related to the effluent quality, as well as the degree of emitter clogging along the laterals. Tentative conclusions and ways to improve the filtration and irrigation efficiency of the effluent and stormwater mixtures have been reached after one irrigation season.
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ABSTRACT
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One of the major problems in operating high-rate oxidation ponds (HROP) so as to give the maximal yield of algae is the determination of the best combination of retention time and effluent depth under varying environmental conditions. The... more
One of the major problems in operating high-rate oxidation ponds (HROP) so as to give the maximal yield of algae is the determination of the best combination of retention time and effluent depth under varying environmental conditions. The criteria for choosing these variables were determined by applying the results previously obtained from pilot and field ponds operated in Israel and via computer simulation techniques. Guidelines for operating the HROP under different climatic conditions are also discussed.
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A wastewater reclamation program has been proposed as a means of supplying a major part of agricultural water demand in Israel. This program may solve the two fold problem of a national water shortage combined with continuous... more
A wastewater reclamation program has been proposed as a means of supplying a major part of agricultural water demand in Israel. This program may solve the two fold problem of a national water shortage combined with continuous contamination of groundwater resources by inadequately treated wastewater. A pilot-scale investigation of an advanced treatment scheme incorporating a sequencing batch activated sludge system, followed by deep-bed granular filtration, has been started. It is aimed at the development of design and operation guidelines for such systems to be applied on a full scale. Preliminary results presented herein indicate that the sequencing batch reactor system is capable of producing high-quality, low-suspended-solids effluent to be further polished by granular filtration. A single medium quartz sand filter operated under a high variety of filtration velocities and inflow turbidities with no chemicals added, demonstrated good performance and supplied basic design information to be applied in further investigation.
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Reuse of treated wastewater is a favorable direction for solving water shortage problems and meeting environmental quality criteria. Domestic wastewater in isolated communities in arid regions can be treated efficiently in a stabilization... more
Reuse of treated wastewater is a favorable direction for solving water shortage problems and meeting environmental quality criteria. Domestic wastewater in isolated communities in arid regions can be treated efficiently in a stabilization pond systems. The effluent quality can be further improved when stored in a series of stabilization reservoirs. There are a series of parameters, which characterize the effluent quality for agricultural reuse. The conventional biological parameters include fecal coliforms as a microbial indicator. The use of fecal coliforms does not reflect the viral pollution of the effluent due to the poor correlation with virus occurrence. Therefore, phages are proposed as enteric virus pollution indicators. Phages exhibit similar behavior and survival in aquatic environment, and their quantitative assessment is easy and a reliable enteric virus measure. Field results from the treatment plant of the City of Arad (Israel) reveal the possibility of characterizing the effluent quality in a stabilization pond and reservoir system. The treatment plant includes a porous rock dike, resembling a horizontal trickling filter.
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The work considers the problem of determining an optimal operational plan in order to maximize the profits of an agricultural enterprise. A decision model is formulated considering a set of potential crops for planting on an available... more
The work considers the problem of determining an optimal operational plan in order to maximize the profits of an agricultural enterprise. A decision model is formulated considering a set of potential crops for planting on an available area of land, two sources of water supply of different qualities and limited capacities, and a production function for each crop using water quantity and quality as the input factors. A unique feature of the model concerns the nature of the production function, which measures the profit margin of a crop not only in terms of its yield, but also the quality of the products. The model was developed to assist local decision makers in the Negev Desert (Israel) for the purpose of soliciting a preferred policy for water sources development. The developed model may be applicable for other regions with similar water shortage problems.
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Field experiments were conducted to evaluate the reuse of domestic, secondary treated wastewater for irrigation of edible crops. Corn was irrigated under on-surface and subsurface trickle systems with effluent and compared with on-surface... more
Field experiments were conducted to evaluate the reuse of domestic, secondary treated wastewater for irrigation of edible crops. Corn was irrigated under on-surface and subsurface trickle systems with effluent and compared with on-surface trickle irrigation applying fresh water. The results indicate that under sub-surface trickle irrigation fruit contamination is minimal.
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Waste water treatment and recycling facilities are becoming increasingly necessary in arid zones, especially in the light of the shortage of conventional water sources. The simultaneous treatment of waste water and the production of... more
Waste water treatment and recycling facilities are becoming increasingly necessary in arid zones, especially in the light of the shortage of conventional water sources. The simultaneous treatment of waste water and the production of duckweed in a pond system, as an alternative protein source, is an attractive proposition for solving the feed and water shortage problem. Outdoor experiments conducted in mini-ponds showed that duckweed ponds may be highly competitive with existing secondary treatment methods. The duckweed biomass, with a crude protein content of above 30% (dry weight), may be used as an alternative source for animal feed. The ease of the duckweed harvesting makes the system even more economically attractive. The work describes the basic outdoor biotechnology aimed at eliminating the superior organic loading in the pond as given by the ratio of COD and NH+4 in the raw domestic sewage. This ratio was examined in respect to the retention time of the wastes in the ponds and protein production by the floating vascular plant biomass.
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The project exploits the use of Artificial Neural Networks (ANN) to describe infiltration, water, and solute distribution in the soil during irrigation. It provides a method of simulating water and solute movement in the subsurface which,... more
The project exploits the use of Artificial Neural Networks (ANN) to describe infiltration, water, and solute distribution in the soil during irrigation. It provides a method of simulating water and solute movement in the subsurface which, in principle, is different and has some advantages over the more common approach of numerical modeling of flow and transport equations. The five objectives were (i) Numerically develop a database for the prediction of water and solute distribution for irrigation; (ii) Develop predictive models using ANN; (iii) Develop an experimental (laboratory) database of water distribution with time; within a transparent flow cell by high resolution CCD video camera; (iv) Conduct field studies to provide basic data for developing and testing the ANN; and (v) Investigate the inclusion of water quality [salinity and organic matter (OM)] in an ANN model used for predicting infiltration and subsurface water distribution. A major accomplishment was the successful use of Moment Analysis (MA) to characterize “plumes of water” applied by various types of irrigation (including drip and gravity sources). The general idea is to describe the subsurface water patterns statistically in terms of only a few (often 3) parameters which can then be predicted by the ANN. It was shown that ellipses (in two dimensions) or ellipsoids (in three dimensions) can be depicted about the center of the plume. Any fraction of water added can be related to a ‘‘probability’’ curve relating the size of the ellipse (or ellipsoid) that contains that amount of water. The initial test of an ANN to predict the moments (and hence the water plume) was with numerically generated data for infiltration from surface and subsurface drip line and point sources in three contrasting soils. The underlying dataset consisted of 1,684,500 vectors (5 soils×5 discharge rates×3 initial conditions×1,123 nodes×20 print times) where each vector had eleven elements consisting of initial water content, hydraulic properties of the soil, flow rate, time and space coordinates. The output is an estimate of subsurface water distribution for essentially any soil property, initial condition or flow rate from a drip source. Following the formal development of the ANN, we have prepared a “user-friendly” version in a spreadsheet environment (in “Excel”). The input data are selected from appropriate values and the output is instantaneous resulting in a picture of the resulting water plume. The MA has also proven valuable, on its own merit, in the description of the flow in soil under laboratory conditions for both wettable and repellant soils. This includes non-Darcian flow examples and redistribution and well as infiltration. Field experiments were conducted in different agricultural fields and various water qualities in Israel. The obtained results will be the basis for the further ANN models development. Regions of high repellence were identified primarily under the canopy of various orchard crops, including citrus and persimmons. Also, increasing OM in the applied water lead to greater repellency. Major scientific implications are that the ANN offers an alternative to conventional flow and transport modeling and that MA is a powerful technique for describing the subsurface water distributions for normal (wettable) and repellant soil. Implications of the field measurements point to the special role of OM in affecting wettability, both from the irrigation water and from soil accumulation below canopies. Implications for agriculture are that a modified approach for drip system design should be adopted for open area crops and orchards, and taking into account the OM components both in the soil and in the applied waters.
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... Consequently, the reduced land requirements for the rocky pond help to offset the disadvantage of classical WSP systems. ... more than 90% of F-specific bacteriophages are RNA-phages, and are commonly more resistant to ultraviolet... more
... Consequently, the reduced land requirements for the rocky pond help to offset the disadvantage of classical WSP systems. ... more than 90% of F-specific bacteriophages are RNA-phages, and are commonly more resistant to ultraviolet light inactivation (lAWPRC, l99l; Brion et al ...
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Two drip irrigation systems for on-surface and subsurface effluent application were installed in sweet corn (Zea mays L. var. saccharatum) experimental fields. Effects of secondary effluent on yield and bacterial contamination in the soil... more
Two drip irrigation systems for on-surface and subsurface effluent application were installed in sweet corn (Zea mays L. var. saccharatum) experimental fields. Effects of secondary effluent on yield and bacterial contamination in the soil and the corn plants were studied. Results were compared with those obtained for sprinkle irrigated plots. Bacterial contamination of the crop was maximal under sprinkle irrigation and minimal under drip application.
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The main purpose of the research was to examine approaches and to evaluate methods for minimizing the risks during applying treated domestic wastewater for agricultural irrigation. This general purpose consisted of examining under field... more
The main purpose of the research was to examine approaches and to evaluate methods for minimizing the risks during applying treated domestic wastewater for agricultural irrigation. This general purpose consisted of examining under field conditions the possibilities when implementing different application technologies for minimizing health and environmental risks. It was assumed that Subsurface Drip Irrigation (SDI) will provide adequate conditions for safe effluent reuse. Controlled field experiments where conducted in commercial fields to evaluate the alternatives. Main efforts where conducted in Israel in the grape vineyard in Arad heights, in the field crops in Kibbutz Chafets Chaim and in Arizona in fields adjacent to the University campus. The complementary part was to examine the behavior of the various pathogens in the effluent-soil-plant system. The analysis is based on controlled experiments, primarily in greenhouse along with field experiments. Molecular biology methods we...
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The work described here is designed to guide Engineers, Planners, Hydrologists,and practitioners in the principles involved when one considers Water transportation from one region with sufficient water sources to a semi-arid region. The... more
The work described here is designed to guide Engineers, Planners, Hydrologists,and practitioners in the principles involved when one considers Water transportation from one region with sufficient water sources to a semi-arid region. The principles described in this Manuscript can easily be replicated to areas with similar conditions of Tanzania. The Mathematical tools are simple and optimization of costs may easily be determined to decide the feasible options for water transportation to supply the dry region. The case study presented in this Manuscript has data scarcity. Assumptions and statistical methods to improve the estimations have been employed.
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An analysis of closed conduit irrigation systems towards minimal system cost is presented, using a nonlinear mixed integer optimization procedure. Emphasis is on the subdivision of the system into subunits and the relationship between the... more
An analysis of closed conduit irrigation systems towards minimal system cost is presented, using a nonlinear mixed integer optimization procedure. Emphasis is on the subdivision of the system into subunits and the relationship between the subunits, design parameters and system cost. The variables defined in the objective function and constraints are the number of manifold and lateral outlets, sizes of mains, submains, supplies, manifolds and laterals. An application example is given.
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An integrative approach for optimal membrane selection concerning desalting of brackish water is proposed. This approach is based on management modeling for the following subsystems: Intake, pretreatment, Reverse-Osmosis (RO) unit,... more
An integrative approach for optimal membrane selection concerning desalting of brackish water is proposed. This approach is based on management modeling for the following subsystems: Intake, pretreatment, Reverse-Osmosis (RO) unit, post-treatment and brine disposal. The management modeling takes into account membrane performance considerations that include treatment levels and technical capabilities. Attention is also given to membrane replacement and permeates salinity. The model is based on defining an objective (cost) function to be optimized. The optimum of the objective function is evaluated, subject to a series of technological and economical constraints. The results provide guidelines for optimal membrane selection, pretreatment technology and information regarding the system layout, optimal investment and water cost. According to the results, a design based on gravity filters and high flux membranes is preferred with respect to minimum permeate cost. Analyzing the results, i...
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There is an increasing trend to use greywater for irrigation in households. This is partly due to the notion that greywater is of better quality than wastewater and therefore does not need extensive treatment beyond addressing public... more
There is an increasing trend to use greywater for irrigation in households. This is partly due to the notion that greywater is of better quality than wastewater and therefore does not need extensive treatment beyond addressing public health issues. The aim of the study was to evaluate the environmental impact and health risks associated with the use of greywater for irrigation on a small private farm. Over a three-year period, each of three plots on a farm was irrigated with either freshwater, fertilized water, or greywater. Irrigation water and soil from the plots were analyzed for a wide range of chemical and microbial variables. Results suggest that greywater may be of similar quality to wastewater in several parameters such as BOD and faecal coliforms. For some other variables such as boron and surfactants, greywater may even be of worse quality than wastewater. Long-term irrigation of arid loess soil with greywater may result in accumulation of salts, surfactants and boron in t...
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Algal growth in wastewater ponds has two contradicting effects on fecal coliforms (FC) decay. On the one hand, algal photosynthesis increases the FC decay due to increased pH and DO. However, on the other hand, attenuation of solar... more
Algal growth in wastewater ponds has two contradicting effects on fecal coliforms (FC) decay. On the one hand, algal photosynthesis increases the FC decay due to increased pH and DO. However, on the other hand, attenuation of solar radiation by algal matter reduces the decay rate. It was therefore investigated if suppressing algal development could enhance the FC removal efficiency. Limiting the algal growth was accomplished by inserting duckweed ponds in between a series of algal ponds. Duckweed ponds are modified stabilization ponds, covered with a mat of small floating plants, that are known to remove algal from algal pond effluent. The FC decay in a series of five shallow algal ponds was compared to FC decay in an integrated system of algal and duckweed ponds. The integrated system consisted of five mini-ponds (30 cm depth) in series: duckweed pond – algal pond – duckweed pond – algal pond – duckweed pond. The environmental factors that are known to affect FC decay were monitore...
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Cryptosporidium parvum and Giardia lamblia are protozoan parasites that cause major human infections through waterborne transmission. The presence of these two parasites is closely linked with effluent reuse. Since most of the effluent,... more
Cryptosporidium parvum and Giardia lamblia are protozoan parasites that cause major human infections through waterborne transmission. The presence of these two parasites is closely linked with effluent reuse. Since most of the effluent, primarily in arid and semi-arid regions is reused for agricultural irrigation, extra work was conducted in order to detect these parasites in wastewater, the applied effluent, soil and crops. Unrestricted irrigation of a variety of vegetables with low-quality effluents could lead to crop contamination with large amounts of Cryptosporidium oocysts and Giardia cysts. A special occurrence was observed with zucchini that will be discussed further. Sprinkle, surface and subsurface dripping irrigation revealed that the last two methods are much safer for unrestricted irrigation, using the soil as an efficient filter matrix. Nevertheless, from the obtained results (using a new method for parasite recovery from soil) both protozoan parasites were isolated from soil, revealing their migration to a depth of 60 and 90 cm below surface when subsurface dripping irrigation was applied. These results will be further discussed as linked to optimization of secondary wastewater reuse in order to minimize environmental risk.
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ABSTRACT This study presents the tests of an Immersed Membrane BioReactor (IMBR) equipped with a draft tube and focuses on the influence of hydrodynamic conditions on membrane fouling in a pilot-scale using a hollow fiber membrane module... more
ABSTRACT This study presents the tests of an Immersed Membrane BioReactor (IMBR) equipped with a draft tube and focuses on the influence of hydrodynamic conditions on membrane fouling in a pilot-scale using a hollow fiber membrane module of ZW-10 under ambient conditions. In this system, the cross-flow velocities across the membrane surface were induced by a cylindrical draft-tube. The relationship between cross-flow velocity and aeration strength and the influence of the cross-flow on fouling rate (under various hydrodynamic conditions) were investigated using Multi-Dimension Scaling (MDS) analysis. MDS technique is especially suitable for samples with many variables and has relatively few observations, as the data about Membrane Bio-Reactor (MBR) often is. Observations and variables are analyzed simultaneously. According to the results, a specialized form of MDS, CoPlot enables presentation of the results in a two dimensional space and when plotting variables ratio (output/input) rather than original data the efficient units can be visualized clearly. The results indicate that: (i) aeration plays an important role in IMBR performance; (ii) implementing the MDS approach with reference to the variables ratio is consequently useful to characterize performance changes for data classification.
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Nanotechnology applications can be used for filtering low quality waters, allowing under given conditions, the removal of salts and other micropollutants from these waters. A long-term field experiment, implementing nanotechnology in the... more
Nanotechnology applications can be used for filtering low quality waters, allowing under given conditions, the removal of salts and other micropollutants from these waters. A long-term field experiment, implementing nanotechnology in the form of UltraFiltration (UF) and Reverse Osmosis (RO) for salt removal from treated wastewater, was conducted with secondary effluents, aiming to prove the sustainability of agricultural production using irrigation with treated wastewater. Six outdoor field treatments, each under four replications, were conducted for examining the salt accumulation effects on the soil and the crops. The field experiments proved that crop development is correlated with the water quality as achieved from the wastewater filtration capability of the hybrid nanotechnology system. The key goal was to maintain sustainable food production, despite the low quality of the waters. Of the six treatment methods tested, irrigation with RO-treated effluent produced the best results in terms of its effect on soil salinity and crop yield. Nevertheless, it must be kept in mind that this process is not only costly, but it also removes all organic matter content from the irrigation water, requiring the addition of fertilizers to the effluent.
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Abstract Reverse Osmosis (RO) is one of the most efficient methods for salt removal from seawater, saline water and from wastewater. However, efficient application of RO for such purposes is still hindered by several operational... more
Abstract Reverse Osmosis (RO) is one of the most efficient methods for salt removal from seawater, saline water and from wastewater. However, efficient application of RO for such purposes is still hindered by several operational drawbacks, the main one being membrane fouling. Herein, field experiments were conducted on a commercial scale membrane system treating domestic wastewater for agriculture irrigation. It was conducted for developing and verifying of a simple and practical tool for evaluating RO membrane fouling. The membrane system consisted of an UltraFiltration (UF) stage and a complementary RO one. The UF component is applied for the removal of the organic matter and pathogenic bacteria while the RO is used for the dissolved solids removal from the wastewater, bringing the water to drinking quality. In our field experiments the membrane system capacity was around 125 m 3 /day and it was run smoothly for a continuous period of four years, providing unrestricted quality effluent that was used for irrigation of a series of seasonal commercial field crops. Following analysis of both field and theoretical data, it was found that back flushing with clean water without adding extra chemicals can be applied in order to minimize fouling of the RO component. Back flushing has two major benefits: saving expenses for the chemicals utilization and improved environmental control.