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Accelerating biodegradation of an azo dye by using its inorganic intermediates
Author(s) -
Zhang Chengji,
Peng Qian,
Xuan Runhe,
Zhang Yongming,
Xue Gang,
Sun Weihua
Publication year - 2021
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6761
Subject(s) - biodegradation , chemistry , effluent , wastewater , anaerobic exercise , inorganic ions , environmental chemistry , ion , organic chemistry , environmental engineering , environmental science , physiology , biology
BACKGROUND The discharge of textile wastewater can cause various environment problems. How to remove these dyes in effluents effectively remains a major concern in wastewater treatment. In this work, the accelerating biodegradation effect of two inorganic intermediates generated by UV irradiation on a monoazo dye, Acid Orange 7 (AO7), was studied in a biofilm reactor. RESULTS The biodegradation reaction fitted well with fractional‐order kinetics. The promotion effects of k trend for the two inorganic intermediates were NH 4 + addition > SO 4 2− addition (> AO7 biodegradation alone). NH 4 + ions increased biochemical oxygen demand (BOD) gradually: compared with 0.5 mg L −1 addition protocol, the BOD of 3 mg L −1 addition protocol was enhanced about five‐fold. SO 4 2− ions showed a positive effect at low concentration and a negative effect at high concentration. In addition, the effect of the two inorganic intermediates on aerobic microbial respiration rate (i.e. SOUR) was similar to BOD. Based on the analysis of high‐throughput sequencing and cluster of orthologous groups, a mechanism of accelerating azo dye biodegradation by using its available intermediates was proposed. CONCLUSION This work revealed that the main inorganic intermediates of the azo dye could accelerate its biodegradation rates. In addition, the bioreactor provided an integrated anaerobic/aerobic micro‐environment that was beneficial to promoting this acceleration effect. © 2021 Society of Chemical Industry (SCI).