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Effect of partial flocculation and adsorption as pretreatment to ultrafiltration
Author(s) -
Shon H. K.,
Vigneswaran S.,
Ngo H. H.
Publication year - 2006
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.10597
Subject(s) - flocculation , chemistry , adsorption , ultrafiltration (renal) , effluent , powdered activated carbon treatment , chromatography , activated carbon , nuclear chemistry , environmental engineering , organic chemistry , engineering
In this study, the sufficiency of flocculation and adsorption with reduced doses of ferric chloride and powdered activated carbon (PAC) as pretreatment to ultrafiltration (UF) was investigated. A 50 mg/L dose of FeCl 3 and 0.5 g/L of PAC removed a majority of organic matter (OM; 88%), thus reducing the organic loading on UF that was used as posttreatment. Although flocculation with lower doses of FeCl 3 (10 mg/L) followed by PAC adsorption of 0.5 g/L and UF removed the same amount of organics (∼88% OM), the majority of the OM removal was by the posttreatment of UF rather than by pretreatment, resulting in a significant decline of flux in UF. A detailed relative molecular mass (RMM) distribution analysis was made with flocculation, adsorption, and UF permeates. PAC adsorption decreased the majority of the relative intensity of smaller RMM of OM from the preflocculated water. Flocculation with <40 mg/L FeCl 3 was not sufficient to remove the relative intensity of the large RMM even after a postadsorption. The detailed analysis on weight‐averaged RMM (M w ) indicated that the M w values of OM in the wastewater and in the flocculated effluent were 29,800 daltons (initial), >25,000 (after flocculation with ≤40 mg/L FeCl 3 ), and <1000 (after flocculation with ≥50 mg/L FeCl 3 ). © 2005 American Institute of Chemical Engineers AIChE J, 2006