title: Removal of contaminants and pathogens from secondary effluents using intermittent sand filters.
abstract: Intermittent infiltration percolation of wastewater through unsaturated sand bed is an extensive treatment technique aimed at eliminating organic matter, oxidizing ammonium and removing pathogens. The main purpose of this study was to determine the depuration efficiencies of a sand filter to remove contaminants from secondary wastewater effluents. Elimination of pathogenic bacteria (total and faecal coliforms, streptococci) and their relationship with the filter depth were investigated. Results showed a high capacity of infiltration percolation process to treat secondary effluents. Total elimination of suspended solids was obtained. Mean removal rate of BOD(5) and COD was more than 97 and more than 81%, respectively. Other water quality parameters such as NH(4)-N, TKN and PO(4)-P showed significant reduction except NO(3)-N which increased significantly in the filtered water. Efficiency of pathogenic bacteria removal was shown to mainly depend on the filter depth. Average reductions of 2.35 log total coliforms, 2.47 log faecal coliforms and 2.11 log faecal streptococci were obtained. The experimental study has shown the influence of the temperature on the output purification of infiltration percolation process.
authors: Department of Geology, Faculty of Sciences, Tunis, Tunisia. mahmoud.bali@yahoo.fr
authors: Mahmoud
authors: M
authors: Bali
authors: Moncef
authors: M
authors: Gueddari
authors: Rachid
authors: R
authors: Boukchina
mesh_terms: D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology; D004755:Enterobacteriaceae / Q000302:isolation & purification* / Q000472:pathogenicity; D013293:Enterococcus faecalis / Q000302:isolation & purification* / Q000472:pathogenicity; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D010865:Pilot Projects; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014416:Tunisia; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D014873:Water Pollutants / Q000302:isolation & purification*
chemical_list: D014873:Water Pollutants; D012822:Silicon Dioxide