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Effect of pH change on the performance and microbial community of enhanced biological phosphate removal process
Author(s) -
Zhang Tong,
Liu Yan,
Fang Herbert H.P.
Publication year - 2005
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.20589
Subject(s) - enhanced biological phosphorus removal , phosphate , chemistry , wastewater , actinobacteria , microbial population biology , sequencing batch reactor , proteobacteria , sewage treatment , bacteria , sewage sludge , pulp and paper industry , environmental chemistry , activated sludge , biochemistry , biology , 16s ribosomal rna , environmental engineering , environmental science , genetics , engineering , gene
An acetate‐rich wastewater, containing 170 mg/L of total organic carbon (TOC), 13 mg/L of N, and 15 mg/L of P, was treated using the enhanced biological phosphate removal (EBPR) process operated in a sequencing batch reactor. A slight change of pH of the mixed liquor from 7.0 to 6.5 led to a complete loss of phosphate‐removing capability and a drastic change of microbial populations. The process steadily removed 94% of TOC and 99.9% of P from the wastewater at pH 7.0, but only 93% TOC and 17% of P 14 days after the pH was lowered to pH 6.5. The sludge contained 8.8% P at pH 7.0, but only 1.9% at pH 6.5. Based on 16S rDNA analysis, 64.8% of the clones obtained from the sludge at pH 7.0 were absent in the pH 6.5 sludge. The missing microbes, some of which were likely responsible for the phosphate removal at pH 7.0, included β‐ Proteobacteria , Actinobacteria , Bacteriodetes / Chlorobi group, plus photosynthetic bacteria and Defluvicoccus of the α‐ Proteobacteria . Among them, the last two groups, which represented 9.3% and 10.1% of the EBPR sludge at pH 7.0, have rarely been reported in an EBPR system. © 2005 Wiley Periodicals, Inc.