Xiao Yang, Liu Yaoze, Ma Changjian, Muhammad Tahir, Zhou Bo, Zhou Yunpeng, Song Peng, Li Yunkai
College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, Albany, NY 12222, USA.
J Hazard Mater. 2021 Jan 5;401:123265. doi: 10.1016/j.jhazmat.2020.123265. Epub 2020 Jun 22.
Reusing biogas slurry (BS) in agricultural drip irrigation systems may provide a solution to deal with the adverse environmental impacts of applying BS. Biofouling and scaling are two leading issues in drip irrigation emitters. This study investigated a practice that applied electromagnetic fields (EMFs) to control biofilms and scales. The bacterial communities and mineral precipitations in the clogging substances of emitters were determined. Results showed that EMFs inhibited the growth of microbes, and influenced BS physicochemical parameters. Consequently, EMFs shifted the bacterial communities with reduced diversities. Network analyses revealed that bacterial species under EMFs treatments showed lower average connectivities and simpler interactions, which were responsible for the decreases of extracellular polymers substances (EPS). Moreover, EMFs treatments not only reduced the carbonates in emitters, but also prevented the depositions of phosphates, silicates, and quartzes. EMFs also had impacts on the lattice parameters and crystal volumes of carbonates. In addition, the changes in bacterial communities and EPS contents were associated with the reductions of various minerals. Accordingly, EMFs effectively mitigated biofilms and scales with the fixed clogging substances reduced by 29.1-53.8 %. These findings demonstrated that applying EMFs is an effective anti-biofouling and anti-scaling treatment with potential applications in BS irrigation systems.
在农业滴灌系统中回用沼液（BS）或许能为应对施用沼液带来的不利环境影响提供一种解决方案。生物污垢和结垢是滴灌喷头面临的两大主要问题。本研究调查了一种应用电磁场（EMF）来控制生物膜和水垢的做法。测定了喷头堵塞物质中的细菌群落和矿物沉淀情况。结果表明，电磁场抑制了微生物的生长，并影响了沼液的理化参数。因此，电磁场使细菌群落发生了变化，多样性降低。网络分析显示，经电磁场处理的细菌物种平均连通性较低，相互作用更简单，这导致了胞外聚合物物质（EPS）的减少。此外，电磁场处理不仅减少了喷头中的碳酸盐，还防止了磷酸盐、硅酸盐和石英的沉积。电磁场还对碳酸盐的晶格参数和晶体体积产生影响。此外，细菌群落和EPS含量的变化与各种矿物质的减少有关。因此，电磁场有效地减轻了生物膜和水垢，固定堵塞物质减少了29.1%至53.8%。这些研究结果表明，应用电磁场是一种有效的抗生物污垢和抗结垢处理方法，在沼液灌溉系统中具有潜在的应用价值。
