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Activated Sludge Inhibition by Chemical Stressors—A Comprehensive Study
Author(s) -
Henriques Inês D. S.,
Kelly Richard T.,
Dauphinais Jennifer L.,
Love Nancy G.
Publication year - 2007
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143007x156709
Subject(s) - chemistry , activated sludge , cyanide , chemical oxygen demand , ammonia , respiration , environmental chemistry , cadmium , biomass (ecology) , flocculation , inorganic chemistry , sewage treatment , environmental engineering , biochemistry , organic chemistry , biology , botany , environmental science , agronomy
The effects of shock loads of 1‐chloro‐2,4‐dinitrobenzene (CDNB); cadmium; 1‐octanol; 2,4‐dinitrophenol (DNP); weakly complexed cyanide; pH 5, 9, and 11; and high ammonia levels on activated sludge biomass growth, respiration rate, flocculation, chemical oxygen demand removal, dewaterability, and settleability were studied. For all chemical shocks, except ammonia and pH, concentrations that caused 15, 25, and 50% respiration inhibition were used to provide a single pulse shock to sequencing batch reactor systems containing a nitrifying or non‐nitrifying biomass. Cadmium and pH 11 shocks were most detrimental to all processes, followed by CDNB. The DNP and cyanide primarily affected respiration, while pH 5, pH 9, octanol, and ammonia did not affect the treatment process to a significant extent. A chemical source–process effect matrix is provided, which we believe will aid in the development of methods that prevent and/or attenuate the effects of toxic shock loads on activated sludge systems.