In addition to the future requirements for enhanced coagulation, some systems may benefit from increasing coagulant dose beyond that required by the D/DBP Rule. For example, systems with high raw water TOC levels may further reduce regrowth potential in the distribution system by increasing coagulant dose beyond future requirements. In general, the optimal pH for TOC removal is in the range of 5.5 to 6.0 with alum coagulant dosages ranging from 5 to 10 mg ferric coagulant/mg of TOC. The nature and concentration of NOM will dictate the treatment process adopted, especially the coagulant type and dose, polymer type and dose, and oxidant type and dose. Higher coagulant dosages can significantly increase sludge volume and quality that need to be treated prior to disposal. Because of the possible adverse impacts to existing residuals management programs from enhanced and optimized coagulation to further reduce distribution system regrowth potential and DBP formation potential, it is essential that quantitative and qualitative assessments of future residuals production be made prior to the implementation of any increase in coagulant dose.
Product Details
Published: 01/01/1994 ISBN(s): 0898677750 Number of Pages: 20File Size: 1 file , 650 KB