Full Description

The practice of recycling filter backwash water (FBWW) has become common in many NorthAmerican water treatment plants. Although direct discharge to waterways of clarified wastestreams is a widely practiced disposal method, recycling the generated wastewater is an attractiveoption for utilities governed by strict plant economics and increasing government dischargeregulations. Backwashing a plant's conventional or direct filtration process units can consumeup to 3-10 % of the treated water produced, and generates an equally significant volume ofwastewater, termed as filter backwash water (FBWW) that must be managed. Filter backwashwater consists of metal-hydroxides, concentrated microorganisms and dissolved organic andinorganic contaminants. FBWW and clarifier sludge generally comprise the majority of thewaste residual volume generated, and in relative terms can be collectively referred to ascombined filter backwash water (CFBWW). As a result of pathogen outbreaks attributed toinadequate clarification of backwash water, utilities are considering more advanced treatmentmethods for these waste residual streams. The objective of this studywas to evaluate the impact of blending treated water with FBWW that had been treated with asubmersed ultrafiltration (UF) system. In particular, this study examined water distributionissues concerning microbiological regrowth and the formation of chlorinated disinfection byproducts(DBPs) originating from disinfection with free chlorine, chlorine dioxide orchloramines on water that received a 10% blend of UF treated CFBWW. Includes 3 references, tables, figure.

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Edition: Vol. - No. Published: 11/02/2003 Number of Pages: 5File Size: 1 file , 260 KB