消毒剂卫可施用对猪粪污厌氧消化系统运行及微生物多样性的影响

Effects of VirkonTM application on the operation and microbial diversity of the anaerobic digestion system in pig farms

为全面评估大量消毒剂施用对猪场粪污厌氧发酵系统造成的损害程度,选择卫可(VirkonTM)消毒剂为研究对象,在全自动甲烷潜力测试系统(AMPTSⅡ)中采取一次性投料的厌氧湿式发酵方式,探索质量浓度为0.05%和0.5%的卫可对系统产CH4、水质污染物降解、微生物群落等方面影响。结果表明:卫可会导致厌氧发酵系统出现抑制产CH4、COD不降反升、大幅促进氮磷释放等异常现象。对照组(CK组,新鲜猪粪添加接种污泥)和0.05%、0.5%卫可试验组(分别记为L组和H组)的最大产CH4速率分别为(23.54±0.06)、(18.90±1.49)mL·g^(-1)·d^(-1)、(7.73±0.01)mL·g^(-1)·d^(-1),且L组和H组的CH4总产量分别降低7.53%和92.60%(P<0.001),而CH4速率常数也由0.267 d^(-1)(CK组)下降到0.225 d^(-1)(L组);理化指标方面,在第0天(启动期)和第12天(结束期),H组较CK组的COD、TP、NH_(3)-N、TN分别显著高出148.77%和368.97%、214.11%和498.12%、64.79%和44.37%、68.77%和53.30%。高通量测序发现,卫可会使厌氧系统中细菌群落组成、多样性和丰度发生显著变化,其中Ace、Chao和Shannon指数,L和H组均低于CK组,而Simpson指数则相反;厚壁菌门(Firmicutes)是第一优势菌群,其次是变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)和拟杆菌门(Bacteroidetes),其他微生物丰度均低于5%,且Firmicutes丰度与卫可剂量呈正相关,Proteobacteria、Chloroflexi和Bacteroidetes则相反,甚至热袍菌门(Thermotogae)和阴沟单胞菌门(Cloacimonetes)会因高剂量卫可而消失;在属水平,束毛球菌属(Trichococcus)由42%~59%降至12%~30%,消化链球菌属(Peptostreptococcus)、埃希氏-志贺菌属(Escherichia-Shigella)和Macellibacteroides属则显著增加。

To comprehensively evaluate the degree of damage caused by the application of a large number of disinfectants to the anaerobic fermentation system of manure in pig farms,VirkonTM disinfectant was selected as the research object.The effects of 0.05%and 0.5%VirkonTM on CH4 production,water pollutant degradation,and microbial communities in the system were explored through anaerobic wet fermentation with one-time feeding in the Automatic Methane Potential Test SystemⅡ.The results showed that VirkonTM could inhibit the production of CH4,increase COD,and greatly promote the release of nitrogen and phosphorus in the anaerobic fermentation system.The maximum gas production rate of the control check group(CK group),0.05%,and 0.5%VirkonTM groups(L group and H group,respectively)were(23.54±0.06),(18.90±1.49)mL·g^(-1)·d^(-1),and(7.73±0.01)mL·g^(-1)·d^(-1),respectively.The total CH4 production of groups L and H decreased by 7.53%and 92.60%(P<0.001),respectively.While the CH4 rate constant decreased from 0.267 d^(-1)(CK group)to 0.225 d^(-1)(L group).In terms of physical and chemical indicators:on the 0th day(start-up phase)and the 12th day(end phase),in the H group compared with the CK group,COD increased by 148.77%and 368.97%,TP increased by 214.11%and 498.12%,NH_(3)-N increased by 64.79%and 44.37%,and TN increased by 68.77%and 53.30%,respectively.Simultaneously,all of them showed significant differences.High-throughput sequencing found that VirkonTM caused significant changes the composition,diversity and abundance of bacterial communities in the anaerobic systems.The Ace,Chao,and Shannon indexes in the L and H groups were lower than those in the CK group,while the opposite was seen for the Simpson index.The Firmicutes was found to be the first dominant bacterial group,followed by Proteobacteria,Chloroflexi,and Bacteroidetes.The abundance of other microorganisms were all lower than 5%,and Firmicutes increased with the increase of VirkonTM concentration,but Proteobacteria,Chloroflexi,and Bacteroidetes were the opposite.And even Thermotogae and Cloacimonetes disappeared due to high doses of VirkonTM.At the genus level,Trichococcus decreased from 42%–59%to 12%–30%;in contrast,Peptostreptococcus,Escherichia-Shigella,and Macellibacteroides were increased significantly.