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Optimizing enhanced coagulation with PAC: A case study
Author(s) -
Najm Issam,
Tate Carol,
Selby Douglas
Publication year - 1998
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.1998.tb08521.x
Subject(s) - coagulation , chemistry , powdered activated carbon treatment , water treatment , ferric , total organic carbon , chloride , organic matter , pulp and paper industry , dose , flocculation , natural organic matter , activated carbon , nuclear chemistry , environmental chemistry , environmental engineering , organic chemistry , environmental science , psychology , adsorption , psychiatry , engineering , medicine , pharmacology
Enhanced coagulation plus PAC achieves required NOM removals at minimum cost. Enhanced coagulation can remove only a finite fraction of the natural organic matter (NOM) in water. Supplementing enhanced coagulation with powdered activated carbon (PAC) increases the removal of NOM and disinfection by‐product (DBP) precursors. The removal of total organic carbon (TOC) and DBP precursors from Colorado River water was evaluated in an experimental matrix of jar tests using four ferric chloride dosages and four PAC dosages. On the basis of the chemical dosages used, the cost of each combination of coagulant and PAC addition was estimated. For a given TOC removal goal, a particular combination of ferric chloride and PAC dosages resulted in the lowest chemical costs. The analysis also indicated that this same dosage combination would produce the least sludge at the water treatment plant. This study shows that the combination of a chemical coagulant and PAC can be more cost‐effective than a chemical coagulant alone for meeting the requirements of Stage 1 of the Disinfectants/DBP (D/DBP) Rule. In addition, the combination of a chemical coagulant and PAC may be a cost‐effective alternative to granular activated carbon for meeting the requirements of Stage 2 of the D/DBP Rule.