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Demonstrating Compliance with Stringent Nitrogen Limits Using a Biological Nutrient Removal Process in California's Central Valley
Author(s) -
Merlo Rion,
Witzgall Bob,
Yu William,
Ohlinger Kurt,
Ramberg Steve,
De Las Casas Carla,
Henneman Seppi,
Parker Denny
Publication year - 2015
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 - 10.2175/106143015x14362865227238
Subject(s) - effluent , nitrification , environmental science , activated sludge , wastewater , nitrate , sewage treatment , nutrient , environmental engineering , sanitation , nitrogen , sewage , pulp and paper industry , waste management , chemistry , ecology , biology , engineering , organic chemistry
The Sacramento Regional County Sanitation District (District) must be compliant with stringent nitrogen limits by 2021 that the existing treatment facilities cannot meet. An 11‐month pilot study was conducted to confirm that these limits could be met with an air activated sludge biological nutrient removal (BNR) process. The pilot BNR treated an average flow of 946 m 3 /d and demonstrated that it could reliably meet the ammonia limit, but that external carbon addition may be necessary to satisfy the nitrate limit. The BNR process performed well throughout the 11 months of operation with good settleability, minimal nocardioform content, and high quality secondary effluent. The BNR process was operated at a minimum pH of 6.4 with no noticeable impact to nitrification rates. Increased secondary sludge production was observed during rainfall events and is attributed to a change in wastewater influent characteristics.