Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation, Ministry of Agriculture, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China.
Guangdong Ecological Remediation of Aquaculture Pollution Research Center, Guangzhou, China.
PeerJ. 2023 Jul 24;11:e15756. doi: 10.7717/peerj.15756. eCollection 2023.
Solid-phase denitrification shows promise for removing nitrate (NO-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, NO-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, (0.85%), (0.38%), (4.22%), and (0.60%) have denitrification functions; (0.47%) is mainly involved in the degradation of WH; and (0.37%) and (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.
固相反硝化在去除水中硝酸盐（NO-N）方面显示出很大的潜力。生物反硝化利用外部碳源从废水中去除氮，其中农业废弃物由于其经济和效率优势被认为是最有前途的来源。水力停留时间（HRT）和进水硝酸盐浓度（INC）是影响生物反硝化的主要因素。本研究以麦壳（WH）为碳源，探讨了 HRT 和 INC 对固相反硝化的影响。构建了以麦壳为碳源的固相反硝化系统，以研究不同 HRT 和 INC 下的反硝化性能。WH 反硝化反应器（WH-DR）的最佳 HRT 和 INC 分别为 32 h 和 50 mg/L。在此条件下，NO-N 和总氮去除率分别为 97.37±2.68%和 94.08±4.01%。高通量测序结果表明，WH-DR 运行中的优势菌门为变形菌门、拟杆菌门和泉古菌门。在优势属中，（0.85%）、（0.38%）、（4.22%）和（0.60%）具有反硝化功能；（0.47%）主要参与 WH 的降解；（0.37%）和（0.86%）既能反硝化又能降解 WH。本研究确定了 WH-DR 的最佳 HRT 和 INC，为 WH 作为一种新型、缓释碳源在处理养殖废水中的开发和应用提供了参考。
