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Effects of Fe(III) on floc characteristics of activated sludge
Author(s) -
Li Jiuyi
Publication year - 2005
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.1169
Subject(s) - turbidity , effluent , suspended solids , activated sludge , chemistry , flocculation , total suspended solids , pulp and paper industry , environmental engineering , chemical engineering , sewage treatment , wastewater , environmental science , chemical oxygen demand , biology , ecology , organic chemistry , engineering
The effects of Fe(III) on floc characteristics of activated sludge were investigated in nine parallel sequencing batch reactors (SBRs). The results showed that Fe(III) improved the quality of organic matters in the effluent of reactors. Concentrations of Fe(III) up to 23.8 mg dm −3 decreased suspended solids and turbidity in effluent but overdosage resulted in deterioration of these parameters. Activated sludge floc size measurements indicated that Fe(III) led to a shift in the size distribution from large to small flocs. Concentrations of Fe(III) less than 23.8mg dm −3 did not significantly change the proportion of larger flocs, but overdosage of Fe(III) markedly decreased the fraction of larger flocs and produced a large number of smaller flocs, which may be responsible for the deterioration of effluent suspended solids and turbidity. Scanning electronic microscopic (SEM) observation suggested high Fe(III) concentrations lead to significant changes in floc morphology and reduction of filamentous microorganisms available for the formation of large aggregates. Copyright © 2005 Society of Chemical Industry