Particulate and THM precursor removal with ferric chloride

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Journal of Environmental Engineering (New York)

DOI:https://doi.org/10.1061/(ASCE)0733-9372(1999)125:11(1054)· OSTI ID:20005442

Childress, A E; Vrijenhoek, E M; Elimelech, M; Tanaka, T S; Beuhler, M D

Pilot-scale experiments were performed to investigate the effectiveness of enhanced coagulation in removing particles and trihalomethane (THM) precursors from two surface source waters: California State Project water and Colorado River water. The removal of suspended particles and natural organic matter at various ferric chloride doses and coagulation pHs was assessed through source water and filter effluent measurements of turbidity, particle count. UV{sub 254}, TOC, and THM formation potential. Overall, it was found that optimal removal of particles and THM precursors by enhanced coagulation with ferric chloride is obtained at high coagulant doses and low pH conditions. Generally, turbidity removal is more efficient and head loss is more moderate at ambient pH compared with pH 5.5. Additionally, filter effluent particle counts were found to be consistent with residual turbidity data. The removal of THM precursors by enhanced coagulation is significantly enhanced at pH 5.5 compared with ambient pH. The reduction in THM formation potential is consistent with the trends observed for the THM precursor removal data. Furthermore, specific UV absorbance was used to estimate the proportion of humic substances in the raw waters. Enhanced coagulation was found to be less effective for the source water with the lower specific UV absorbance.

• Research Organization: Univ. of Nevada, Reno, NV (US)
• OSTI ID: 20005442
• Journal Information: Journal of Environmental Engineering (New York), Journal Name: Journal of Environmental Engineering (New York) Journal Issue: 11 Vol. 125; ISSN 0733-9372; ISSN JOEEDU
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
IRON CHLORIDES
ORGANIC HALOGEN COMPOUNDS
PARTICULATES
REMEDIAL ACTION
SURFACE WATERS
WATER POLLUTION CONTROL