Evaluating the effects of Zn(II) on high-rate biogranule-based denitrification: Performance, microbial community and sludge characteristics

• Published in: Bioresource technology Vol. 279; pp. 393 - 397
• Main Authors: Cheng, Ya-Fei, Li, Gui-Feng, Liu, Ying-Yi, Zhu, Bing-Qian, Zhang, Qian, Xue, Yuan, Zhang, Zheng-Zhe, Jin, Ren-Cun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2019
• Subjects: Bioreactors - microbiology; Denitrification; Denitrification - drug effects; Granular sludge; High-throughput sequencing; Inhibition; Microbial community; Microbiota; Nitrates - metabolism; Nitrogen - metabolism; Sewage - microbiology; Zinc - pharmacology; Zn(II); Zn(II); Denitrification; Inhibition; High-throughput sequencing; Granular sludge; Microbial community
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.02.005

[Display omitted] •The suppression threshold of Zn(II) on reactor performance was 10 mg L−1 for long-term exposure.•Castellaniella mainly was devoted to denitrification under no or low Zn(II) stress conditions.•Klebsiella was the dominant denitrifying bacteria under high Zn(II) stress conditions. High-rate denitrification is a popular and efficient process for treatment of nitrate-rich wastewater. Knowing the effect of heavy metals on denitrification is essential for industrial development. In the present study, the long-term impacts of Zn(II) on denitrifying granular sludge were investigated. The suppression threshold of Zn(II) on denitrifying bacteria was 10 mg L−1 for long-term exposure. The nitrogen removal rate was decreased by long-term addition of 10 mg L−1 Zn(II). Castellaniella and Klebsiella were the two dominant genera under Zn(II) stress. The relative abundance of Klebsiella sharply decreased to 4.64% after the addition of 10 mg L−1 Zn(II), whereas Castellaniella was susceptible to 2 mg L−1 Zn(II), revealing that Castellaniella mainly was devoted to denitrification under no or low Zn(II) stress conditions, whereas Klebsiella was effective under high Zn(II) stress.