Effects of hydraulic retention time and influent nitrate concentration on solid-phase denitrification system using wheat husk as carbon source

PeerJ

article

Shuhui Niu¹  Shuwei Gao¹  Kai Zhang¹  Zhifei Li¹  Guangjun Wang¹  Hongyan Li¹  Yun Xia¹  Jingjing Tian¹  Ermeng Yu¹  Jun Xie¹  Minting Zhang³  Wangbao Gong¹ 

[1] Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences;Guangdong Ecological Remediation of Aquaculture Pollution Research Center;Guangdong Shunde Junjian Modern Agricultural Technology Co., Ltd

关键词: Wheat husk;    Solid-phase denitrification;    Hydraulic retention time;    Influent nitrate concentration;    Microbial community;   

DOI  :  10.7717/peerj.15756

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Solid-phase denitrification shows promise for removing nitrate (NO3−-N) from water. Biological denitrification uses external carbon sources to remove nitrogen from wastewater, among which agriculture waste is considered the most promising source due to its economic and efficiency advantages. Hydraulic retention time (HRT) and influent nitrate concentration (INC) are the main factors influencing biological denitrification. This study explored the effects of HRT and INC on solid-phase denitrification using wheat husk (WH) as a carbon source. A solid-phase denitrification system with WH carbon source was constructed to explore denitrification performance with differing HRT and INC. The optimal HRT and INC of the wheat husk-denitrification reactor (WH-DR) were 32 h and 50 mg/L, respectively. Under these conditions, NO3−-N and total nitrogen removal rates were 97.37 ± 2.68% and 94.08 ± 4.01%, respectively. High-throughput sequencing revealed that the dominant phyla in the WH-DR operation were Proteobacteria, Bacteroidetes, and Campilobacterota. Among the dominant genera, Diaphorobacter (0.85%), Ideonella (0.38%), Thiobacillus (4.22%), and Sulfurifustis (0.60%) have denitrification functions; Spirochaeta (0.47%) is mainly involved in the degradation of WH; and Acidovorax (0.37%) and Azospira (0.86%) can both denitrify and degrade WH. This study determined the optimal HRT and INC for WH-DR and provides a reference for the development and application of WH as a novel, slow-release carbon source in treating aquaculture wastewater.

【 授权许可】

CC BY