title: Efficacy of removal of CCL viruses under enhanced coagulation conditions.
abstract: The focus of coagulation as a water treatment process is shifting to accommodate recent regulatory additions that strive to balance the risks between microbial and chemical contamination of drinking water. In this work, enhanced coagulation using increased ferric chloride dose and/or pH adjustment was evaluated for removal efficacy of viruses on the United States Environmental Protection Agency (USEPA) Contaminant Candidate List (CCL), their surrogates, and dissolved organic carbon (DOC). Jar tests demonstrated that optimal DOC removal was achieved using 40 mg/L FeCl3 at a pH between 5 and 6. Under these conditions, bench-scale testing resulted in a maximum removal of 2.58 log units of adenovirus type 4, 2.50 log units of feline calicivirus, 2.32 log units of MS2, 1.75 log units of PRD1, 1.52 log units of phi-X174, 2.49 log units of fr, and 56% of DOC. The trend in virus removals (MS2 and fr > PRD1 and phi-X174) was consistent between bench- and pilot-scale testing; however, pilot-plant removals exceeded bench-scale removals. Feline calicivirus was more efficiently removed than the bacteriophages, thereby suggesting potential for the bacteriophages as suitable surrogates, with MS2 and fr being more representative and PRD1 and phi-X174 (which were removed to a lesser extent) more conservative. The bacteriophages do not appear to be appropriate surrogates for adenovirus.
authors.affiliation: Arizona State University, P.O. Box 875306, Tempe, Arizona 85287-5306, USA. abbaszadegan@asu.edu
authors.forename: Morteza
authors.initials: M
authors.lastname: Abbaszadegan
authors.forename: Brooke K
authors.initials: BK
authors.lastname: Mayer
authors.forename: Hodon
authors.initials: H
authors.lastname: Ryu
authors.forename: Nena
authors.initials: N
authors.lastname: Nwachuku
mesh_terms: D000256:Adenoviridae / Q000302:isolation & purification; D001435:Bacteriophages; D017927:Calicivirus, Feline / Q000302:isolation & purification; D002244:Carbon / Q000737:chemistry / Q000302:isolation & purification; D002712:Chlorides; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals / Q000737:chemistry / Q000302:isolation & purification; D014481:United States; D014484:United States Environmental Protection Agency; D014780:Viruses / Q000302:isolation & purification*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; D009930:Organic Chemicals; D002244:Carbon; C024555:ferric chloride