Treatment of decentralized low-strength livestock wastewater using microcurrent-assisted multi-soil-layering systems: performance assessment and microbial analysis. (May 2022)

• Record Type: Journal Article
• Authors: Liu, Chao; Huang, Guohe; Song, Pei; An, Chunjiang; Zhang, Peng; Shen, Jian; Ren, Shaojie; Zhao, Kai; Huang, Wendy; Xu, Ye; Zheng, Rubing
• Is Part Of: Chemosphere. Volume 294(2022)
• Publication Date: 2022-05
• Subjects: Multi-soil-layering system -- Decentralized livestock wastewater -- Microcurrent -- Rural areas -- Bacterial community; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.133536
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Discharge of decentralized livestock wastewater without effective treatment has become a common problem in rural areas, threatening the regional water environment. A new microcurrent-assisted multi-soil-layering (MSL) system was developed for treating rural decentralized livestock wastewater. The results showed the highest removal rates of chemical oxygen demand (COD) and total phosphorus (TP) in MSL systems reached 95.45% and 92.0%, respectively. The removal rate of total nitrogen (TN) in MSL systems ranged from 60 to 75%. The bacterial diversity changes among MSL systems showed that high-level height of bottom submergence had a positive effect on the abundance of denitrifying bacteria, while low-level height of bottom submergence had a positive impact on the abundance of nitrifying bacteria. The effect of low-level external voltage on bacterial abundance was better than that of high-level external voltage. Both high- and low-level influent C/N ratios had no significant effect on bacterial abundance. The metabolism and activity of microorganisms were promoted with microcurrent stimulation from the perspective of increased bacterial abundance in MSL systems with improved treatment performance. Graphical abstract: Image 1 Highlights: Explored rural livestock wastewater treatment using multi-layering soil system. Developed the novel microcurrent-assisted system for pollutant removal. Revealed the effects of different operating factors on pollutant removal. Analyzed the bacterial diversity in soil mixture blocks through gene sequencing. Investigated the relationship between microcurrent and bacterial diversity.