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Effects of quantitative shock loadings on the constant recycle sludge concentration activated‐sludge process
Author(s) -
Wong Y. K.,
Yang P. Y.
Publication year - 1977
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260190105
Subject(s) - activated sludge , dilution , hydraulic retention time , effluent , wastewater , chemistry , mixed liquor suspended solids , chromatography , chemical oxygen demand , pulp and paper industry , environmental engineering , environmental science , physics , engineering , thermodynamics
The reliability of the process of Ramanathan and Gaudy ( Biotechnol Bioeng. , 13 , 125 (1971)) for the completely mixed activated‐sludge process holding the recycle cell concentration, X R , as a system constant with respect to step changes in hydraulic retention time was investigated. The experiments were run at initial dilution rates of ⅛, ⅙, ¼, and ½ hr −1 treating a soft drink bottling wastewater. The influent substrate concentration was maintained at 1000 mg/liter chemical oxygen demand and the hydraulic recycle ratio at 0.3. The recycle sludge concentration was maintained at about 7000 mg/liter. It was found that the system could accommodate hydraulic shock loads up to 200% positive changes and down to 50%negative changes without disruption of the effluent quality. Shorter retention time of the range studied, from 2 to 8 hr, has the advantage of shorter response time with respect to the response of the concentration of biological solids in the reactor.