PATHOGEN REMOVAL IN EXPERIMENTAL DEEP EFFLUENT STORAGE RESERVOIRS

Studies on batch loaded pilot-scale deep effluent storage reservoirs ( ESR) in NE Brazil using the operating regime of Fill, Rest and Use, ra pidly produced a high microbiological quality effluent suitable for un restricted irrigation ie. within 28 days at water temperatures of 25 d egrees C. There was little vertical variation in water quality in the ESR as the water column turned over at night. Physico chemical quality rather than microbiological quality of the effluent was more likely t o control effluent re-use strategies and purification times as there w ere persistantly high ammonia and sulphide levels. ESR's could be orga nically loaded at rates similar to those used for facultative lagoons either using anaerobic pond effluent or raw sewage but the latter invo lved slightly longer purification times. The ESR's produced no odour p roblems. FC proved a good indicator of microbiological effluent qualit y and helminths could not be detected in the water column ty the time the reservoir was full. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd