Leonid Gillerman

Improved saline-water use under subsurface drip irrigation

Abstract The scarcity of fresh water in arid regions makes saline water a valuable alternative water source for irrigation. Although saline-water use for agricultural irrigation is associated with some reduction in the yield, it is coupled with improved yield quality, as expressed by higher total soluble solids content. Field experiments which are in progress in a pear orchard verify that under subsurface drip irrigation (SDI) with saline water, reasonable yields can be obtained. Moisture and salinity distribution under SDI are better adjusted to the root pattern in the soil, in comparison with the conventional drip irrigation (DI). These distribution patterns explain, to some extent, the reaction of trees to saline-water application.

Membrane technology for sustainable treated wastewater reuse: agricultural, environmental and hydrological considerations

Field experiments were conducted in agricultural fields in which secondary wastewater of the City of Arad (Israel) is reused for irrigation. For sustainable agricultural production and safe groundwater recharge the secondary effluent is further polished by a combined two-stage membrane pilot system. The pilot membrane system consists of two main in row stages: Ultrafiltration (UF) and Reverse Osmosis (RO). The UF stage is efficient in the removal of the pathogens and suspended organic matter while the successive RO stage provides safe removal of the dissolved solids (salinity). Effluents of various qualities were applied for agricultural irrigation along with continuous monitoring of the membrane system performance. Best agricultural yields were obtained when applying effluent having minimal content of dissolved solids (after the RO stage) as compared with secondary effluent without any further treatment and extended storage. In regions with shallow groundwater reduced soil salinity in the upper productive layers, maintained by extra membrane treatment, will guarantee minimal dissolved solids migration to the aquifers and minimize salinisation processes.

Nanotechnology for sustainable wastewater treatment and use for agricultural production: A comparative long-term study

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.

Using Phages for Characterization of Effluent Quality in a Stabilization Pond and Reservoirs System in Arid Regions

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.

Analysis of membrane bioreactor performance for wastewater treatment using ranking methods

ABSTRACT The research compares four types of different designs of membrane bioreactors: (1) with 295-mm draft tube and without plastic carriers; (2) plastic carriers and 295-mm draft tube; (3) plastic carriers and 235-mm draft tube with two meshes around the bottom and top of a draft tube; and (4) plastic carriers without a draft tube. The feed for the reactors was artificial wastewater made from domestic wastewater and chicken manure, and membrane test data were based on a hollow fiber membrane module under ambient desert conditions. Process operation type D is the optimal choice. Mathematical analysis using total ranking methods, multi-indicator decision-making, and Hasse diagram support this choice. Concerning analysis by the different tools, inconsistencies between the rankings are noticed. Partial order ranking, as a method without any pre-assumptions concerning the possible relation between the single parameters, proves to be an elegant ranking method.

Risk Management During Effluent Application for Irrigation

Reuse of treated wastewater is a favourable 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 system. The effluent quality can be further improved when stored in a series of stabilization reservoirs. However the salinity of the wastes in the ponds will increase due to evaporation. There is a series of parameters that characterize the effluent quality for agricultural reuse. The conventional biological parameters include faecal coliforms as a microbial indicator. The use of faecal 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 behaviour and survival in an 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 stabilization ponds and additional reservoir systems. The field data also allows the type of reactor of which the system consists to be defined, and the kinetic expressions for further forecasting of the treatment system behaviour and removal rate of the pathogens.

Data Envelopment Analysis (DEA) for Assessment of Cryptosporidium and Giardia Removal by Membrane Processes

Field data from several research sites related to effluent quality; surface water and back-washed membrane filtrate enables to provide performance estimates efficiencies. The estimates are based on the Data Envelopment Analysis (DEA) method. The exploration focused on individual Ultra-Filtration (UF) and MicroFiltration (MF) experiments allowing determining the membrane performance efficiency in terms of Cryptosporidium and Giardia removal by membrane processes. DEA is an empirically based methodology and the research approach has been found to be effective in the depiction and analysis of complex systems efficiency, where a large number of mutual interacting variables are involved.