|Author:||Smith, E. ; Badawy, A.|
|Book Group Author:||NA|
Transport of E. coli bacteria was investigated in laboratory soil columns for three Egyptian agricultural soils, with aim toward determining a set of site specific criteria for safe and sustainable use of treated wastewater in irrigation in Egypt. In particular, the impacts of varying soil type and hydraulic loading rate (HLR) on E. coli effluent breakthrough curves were examined in the laboratory and simulated using the CXTFIT package to solve a one-dimensional mass transport equation that included advection, dispersion, adsorption, and straining/filtration. The attempt was made to measure the coefficients associated with each mass transfer process from independent experiments. The HLR used in irrigation was found to exert considerable influence on the impact of transport processes on E. coli breakthrough. At low HLRs, adsorption and straining/filtration are significant in addition to advection and dispersion. However, at high HLRs approaching flood irrigation, E. coli is essentially unaffected by reaction processes, with breakthrough a function of advection and dispersion only. Estimating Kd via independent batch experiments did not provide a suitable description of adsorption of E. coli in soil columns. To ensure safe and sustainable reuse of reclaimed wastewater in irrigation, guidelines should account for physical and chemical properties of the soil and other local conditions that may impact residual contaminant transport.
|Pages:||1123 - 1129|
|Journal:||Water Science and Technology|
adsorption, agricultural soils, application to land,irrigation, irrigation water, models, polluted soils, public health,soil pollution, soil types, sustainability, waste water, waste watertreatment, water reuse, Egypt, Escherichia coli, North Africa, Africa,Mediterranean Region, Middle East, Developing Countries, Escherichia,Enterobacteriaceae, Gracilicutes, bacteria, prokaryotes, landapplication, watering, Soil Chemistry and Mineralogy (JJ200), Soil WaterManagement (Irrigation and Drainage) (JJ800) (Revised June 2002)[formerly Soil Water Management], Water Resources (PP200), Pollution andDegradation (PP600), Prion, Viral, Bacterial and Fungal Pathogens ofHumans (VV210) (New March 2000), Human Health and the Environment(VV500), Human Wastes and Refuse (XX300), Industrial Wastes andEffluents (XX400), Mathematics and Statistics (ZZ100)