L Gillerman

Publications of L Gillerman

• Microbial transport in soil caused by surface and subsurface drip irrigation with treated wastewater

  Authors: M.Y. Kouznetsov, Y.A. Pachepsky, L Gillerman, C.J. Gantzer, G Oron

  International Agrophysics. 01/2004;

  The objective of this work was to compare and simulate transport and fate of microorganisms from wastewater for surface and subsurface irrigation methods. Adsorption isotherms and water-contentThe objective of this work was to compare and simulate transport and fate of microorganisms from wastewater for surface and subsurface irrigation methods. Adsorption isotherms and water-content dependent survival were measured for fecal coliforms, somatic coliphages and F-specific RNA phages in batch experiments with treated wastewater and clay loam soil. Column experiments with surface and subsurface trickle irrigation were carried out for the same soil. Results of the column experiments were simulated with a combination of Richards equation for water transport and advective-dispersive model with the first-order nonlinear adsorption and moisture-dependent first-order die-off. Simulations showed that die-off rates in column experiments were much higher than in batch experiments for all three organisms. Somatic coliphages were the most persistent organisms probably because of lower adsorption and die-off. The subsurface irrigation appeared to be efficient in decreasing the number of pathogens in irrigated water and preventing their appearance on soil surface that could lead to produce contamination.

• Hybrid membrane systems for secondary effluent polishing for unrestricted reuse for agricultural irrigation.

  Authors: G Oron, A Bick, L Gillerman, Y Manor

  Water science and technology : a journal of the International Association on Water Pollution Research. 01/2004; 50(6):305-12.

  Field experiments are in progress for secondary wastewater upgrading for unrestricted utilization for agricultural irrigation. The integrative approach of secondary effluent polishing is based onField experiments are in progress for secondary wastewater upgrading for unrestricted utilization for agricultural irrigation. The integrative approach of secondary effluent polishing is based on using a hybrid UltraFiltration (UF) and Reverse Osmosis (RO) membrane pilot system with a capacity of around 1 m3/hr. The UF effluent is used to feed the RO membranes. The RO permeate is subsequently applied for vegetable irrigation. Field results indicate the importance of the UF component in the removal of the organic matter and the pathogens that are still contained in the secondary effluent. Under specific conditions, when the dissolved solids content is relatively low, regarding sanitary and health aspects, the UF effluent can be applied for unrestricted irrigation. During the RO stage most nutrients are removed, allowing application of the effluent without jeopardizing the soil fertility and the aquifers. Preliminary economic assessment indicates that the extra cost for effluent polishing via the UF stage only is in the range of 5 to 15 US cents/m3. The extra cost for the RO stage is also assessed at 10 to 25 US cents/m3. The additional cost depends to a large extent on the quality of the incoming raw secondary effluent and local requirements of the command region.

• Adsorption and survival of faecal coliforms, somatic coliphages and F-specific RNA phages in soil irrigated with wastewater.

  Authors: C Gantzer, L Gillerman, M Kuznetsov, G Oron

  Water science and technology : a journal of the International Association on Water Pollution Research. 02/2001; 43(12):117-24.

  This study was carried out to compare the adsorption and survival of faecal coliforms, somatic coliphages and F-specific RNA phages in soil irrigated with wastewater. Adsorption isotherms showed thatThis study was carried out to compare the adsorption and survival of faecal coliforms, somatic coliphages and F-specific RNA phages in soil irrigated with wastewater. Adsorption isotherms showed that 3-10x more faecal coliforms than somatic coliphages were adsorbed from wastewater onto soil. The adsorption behavior of F-specific RNA phages was intermediate between those of these two microorganisms. In wastewater, the inactivation factor of somatic coliphages at 8-22 degrees C was 5-7 lower than those of faecal coliforms. F-specific RNA phages have a decrease close to faecal coliforms. In soil, at temperatures of 8-22 degrees C and at moistures of 15-35%, somatic coliphages survived longer than the two other microorganisms. These results seemed to be confirmed by the soil column experiments. The rate of inactivation of all microorganisms was lower in soil than in wastewater and depended extensively on soil temperature and moisture content. Survival was optimal at low temperature (8 degrees C) and low moisture content (15%). Thus, somatic coliphages seemed to be a better indicator of faecal contamination than faecal coliforms under our experimental conditions and based only on the two criteria tested (survival and adsorption). Somatic coliphages were able to contaminate the soil over greater distances and survive better in both wastewater and soil than faecal coliforms. These results need to be confirmed by studies on several soil columns using different kinds of soil and different kinds of wastewater.

• Secondary wastewater disposal for crop irrigation with minimal risks.

  Authors: G Oron, R Armon, R Mandelbaum, Y Manor, C Campos, L Gillerman, M Salgot, C Gerba, I Klein, C Enriquez

  Water science and technology : a journal of the International Association on Water Pollution Research. 02/2001; 43(10):139-46.

  A critical objective for any wastewater reuse program is to close the gap between supply of and demand for water and to minimize health and environmental hazards. Thus, the effects of treatedA critical objective for any wastewater reuse program is to close the gap between supply of and demand for water and to minimize health and environmental hazards. Thus, the effects of treated effluent on crops, soils and community health must be considered carefully. When applying wastewater to soil-plant systems, it is to be noted that the passage of water through the soil reduces considerably the number of microorganisms carried out by the reclaimed wastewater. Nevertheless, there is a need to study the real rate of organism decay subject to water quality, soil and vegetable characteristics, and irrigation method. The aim of this work is to determine the fate of the fecal coliforms, coliphages F+ and CN13, and helminth eggs survival during the application of reclaimed wastewater in a vineyard orchard near the City of Arad (Israel) via onsurface and subsurface drip irrigation systems. Wastewater obtained from a stabilization pond, and soil samples were tested and an important decrease of microorganisms was reached in both cases, with the better values obtained with the sub-surface drip irrigation system.