Abyar H, Younesi H, Bahramifar N, Zinatizadeh AA. Biological CNP removal from meat-processing wastewater in an innovative high rate up-flow A
2O bioreactor.
CHEMOSPHERE 2018;
213:197-204. [PMID:
30223124 DOI:
10.1016/j.chemosphere.2018.09.047]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/29/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
A high rate up-flow anaerobic, anoxic and oxic (A2O) bioreactor was designed and operated for meat-processing wastewater (MPW) treatment as a single cost-effective system with the aim of simultaneous CNP removal. The influence of three essential factors, HRT, COD/TN ratio and aerated volume fraction on the reactor performance was assessed using response surface methodology (RSM). The required HRT to reach 98.5% COD removal was achieved at 7.5 h. Simultaneous CNP removal under denitrification rate of 199.4 mg/l.d gave high nitrate to nitrogen gas conversion of 74.6 mg/l. An HRT, COD/TN ratio and aerated volume fraction of 10 h, 100:20 and 60%, respectively, was a favored condition for an efficient nitrogen removal with effluent total Kjeldahl nitrogen (TKN) less than 70 mg/l. Under optimum condition, an HRT, COD/TN and aerated volume fraction of 8 h, 100:14 and 65%, respectively, resulted an effluent phosphorus of 43 mg/l, but 93.97 mg/l phosphorus was released in an anaerobic condition at 6 h. An effluent with a low turbidity of about 1.5 NTU and a sludge volume index (SVI) of 75.9 ml/g was achieved using at HRT of 12.5 h, COD/TN ratio of 100: 8 and aerated volume fraction of 50%. Under these conditions, the removal efficiencies for COD, TKN, nitrate-nitrogen (NO3--N), total nitrogen (TN) and phosphorus (PO43--P) were obtained to be 98.33, 92.06, 91.97, 90.48 and 83.48%, respectively. As a result, the application of the up-flow A2O bioreactor is a promising configuration to get hygienic water from wastewater.
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