School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, People's Republic of China.
School of Ecology and Environment, Ningxia University, Yinchuan 750021, People's Republic of China; Ningxia University Northwest State Key Laboratory of Land Degradation and Ecological Restoration Cultivation Base, Yinchuan 750021, People's Republic of China.
Sci Total Environ. 2024 Jan 1;906:167533. doi: 10.1016/j.scitotenv.2023.167533. Epub 2023 Oct 2.
The limitations of conventional substrates in treating wastewater treatment plant tailwater are evident in subsurface flow constructed wetlands, and the emergence of biochar presents a solution to this problem. The objective of this study was to assess and prioritize the efficacy of various modified reed biochar in removing pollutants when used as fillers in wetland systems. To achieve this, we established multiple simulation systems of vertical groundwater flow wetlands, each filled with different modified reed biochar. The reed biochar was prepared and modified using Pingluo reed poles from Ningxia. We monitored the quality of the effluent water and the diversity of the microbial community in order to evaluate the pollutant removal performance of the modified biochar under different hydraulic retention times in a laboratory setting. The findings indicated that a hydraulic retention time of 24-48 h was found to be optimal for each wetland system. Furthermore, the composite modified biochar system with KMnO and ZnCl exhibited higher levels of dissolved oxygen and lower conductivity, resulting in superior pollutant removal performance. Specifically, the system achieved removal rates of 89.94 % for COD, 85.88 % for TP, 91.05 % for TN, and 92.76 % for NH-N. Additionally, the 16S rRNA high-throughput sequencing analysis revealed that the system displayed high Chao1, Shannon, and Simpson indices of 6548.75, 10.1965, and 0.9944, respectively. The predominant bacterial phyla observed in the wetland system were Proteobacteria, Bacteroidetes, Chloroflexi, Patescibacteria, Firmicutes, and Actinobacteria. Additionally, the denitrifying bacterial class, Rhodobacteriaceae, was found to have the highest content ratio in this system. This finding serves as confirmation that the KMnO and ZnCl composite modified biochar can significantly enhance water purification performance. Consequently, this study offers valuable insights for wastewater treatment plants seeking to implement vertical submersible artificial wetland tailwater improvement projects.
传统基质在处理污水处理厂尾水方面的局限性在地下流人工湿地中显而易见，而生物炭的出现为解决这一问题提供了一种方案。本研究旨在评估和优先考虑各种改性芦苇生物炭作为湿地系统填充材料时去除污染物的功效。为此，我们建立了多个垂直地下水流动湿地模拟系统，每个系统都填充了不同的改性芦苇生物炭。我们使用来自宁夏平罗的芦竹杆制备和改性芦苇生物炭。我们监测了出水水质和微生物群落的多样性，以评估改性生物炭在实验室条件下不同水力停留时间下的污染物去除性能。研究结果表明，对于每个湿地系统，水力停留时间为 24-48 小时是最佳的。此外，KMnO 和 ZnCl 复合改性生物炭系统表现出较高的溶解氧和较低的电导率，从而具有更好的污染物去除性能。具体来说，该系统对 COD 的去除率达到了 89.94%，对 TP 的去除率达到了 85.88%，对 TN 的去除率达到了 91.05%，对 NH-N 的去除率达到了 92.76%。此外，16S rRNA 高通量测序分析表明，该系统的 Chao1、Shannon 和 Simpson 指数分别高达 6548.75、10.1965 和 0.9944。湿地系统中主要的细菌门是变形菌门、拟杆菌门、绿弯菌门、Patescibacteria 门、厚壁菌门和放线菌门。此外，脱氮菌科的 Rhodobacteriaceae 在该系统中的含量比例最高。这一发现证实了 KMnO 和 ZnCl 复合改性生物炭可以显著提高水的净化性能。因此，本研究为寻求实施垂直潜水人工湿地尾水改善项目的污水处理厂提供了有价值的见解。
