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Effect of waste activated sludge pretreatment methods to mitigate Gordonia foaming potential in anaerobic digestion
Author(s) -
Garg Aparna,
Stensel H. David,
Bucher Bob,
Sukapanpotharam Pardi,
Winkler Mari K. H.
Publication year - 2021
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/wej.12636
Subject(s) - activated sludge , anaerobic digestion , chemistry , fermentation , foaming agent , pulp and paper industry , waste management , chromatography , sewage treatment , food science , organic chemistry , methane , engineering , porosity
In this study, waste activated sludge obtained from two full‐scale treatment plants with foaming issues was pretreated with acid/alkali treatment, acid‐phase fermentation, thermal treatment, ultrasonic treatment and metal salt treatment to investigate their effect on foam mitigation. Waste activated sludge was characterized for foaming index prior and after each pretreatment method. Among all pretreatment methods investigated, acid/alkali treatment and acid phase fermentation showed highest reduction of 53% in foaming and in inactivation of Gordonia amarae filaments. Pretreatment methods that resulted in sharp decrease in the foaming index concurred with higher amounts of dead foam formers as confirmed using live/dead staining and the PMA‐qPCR technique. Pretreating with iron(III)chloride gave good foaming reductions with 54% decrease in foaming potential at a concentration of 260 mg/L but did not result in a decline of foam formers as confirmed by live/dead staining. Ultrasonic treatment did not prove effective in lowering the foaming index or killing the G. amarae filaments.