Physico-Chemical Parameters Influencing Faecal Bacterial Survival in Waste Stabilization Ponds

Abstract

In situ studies on waste stabilization ponds (in Portugal) showed that faecal coliform numbers were lowest at positions in the water column where pH, temperature, dissolved oxygen and algae were high. Numbers were not always lowest at the surface where light intensities were highest or in ponds where light penetration had increased through algal grazing by Daphnia. Laboratory studies showed that pH values approaching 9.0 or above increased faecal coliform die-off particularly under nutrient-poor conditions. Elevated temperatures enhanced the pH effect but the level of dissolved oxygen made little difference. Streptococcus, Salmonella and Campylobacter isolates all behaved similarly to the faecal coliforms. Daphnia grazing of the algal population in maturation ponds may reduce the microbial quality of the final effluent. These findings are discussed in relation to pond design.

Effects of Environmental Factors on the Disinfection Performance of a Wastewater Stabilization Pond Operated in a Temperate Climate

“…In this four-year full-scale WSP study, the removal efficiencies of E. coli may increase with increasing temperature. This observation is consistent with a number of studies that have reported increased removal efficiencies of fecal coliforms with increasing temperature [25,[34][35][36][37][38].…”

“…In this four-year full-scale WSP study, the removal efficiencies of E. coli may increase with increasing temperature. This observation is consistent with a number of studies that have reported increased removal efficiencies of fecal coliforms with increasing temperature [25,[34][35][36][37][38]. It should be noted that effects of hydraulic retention [39,40], hydraulic efficiency [39,40], sunlight [3], attachment/sedimentation [9], predation and nutrient availability may all contribute to It should be noted that effects of hydraulic retention [39,40], hydraulic efficiency [39,40], sunlight [3], attachment/sedimentation [9], predation and nutrient availability may all contribute to disinfection in WSPs.…”

Effectiveness of Sewage Treatment System and its Irrigation Potential: the Case of Main Campus of Hawassa University, Ethiopia

“…This raises the pH levels in facultative ponds. Pearson et al (1987c) observed a rise of pH in facultative ponds exceeding 9.0 and this is important in killing faecal coliforms. Ammonia and sulphide toxicity have been observed to be pH-dependent (Konig et al 1987).…”

Improvement of waste water quality by application of mixed algal inocula

“…In addition, microalgae have an ability to assimilate nutrients from the environment (Pearson et al, 1987;Davies-Colley et al, 1999). In natural and constructed wetlands recently studied bacteria removal by algae-based systems have been studied (Nascimento, 1987;Gabrhelov et al, 1991;Mara et al, 1992;Von Sperling, 2005).…”