农村三格化粪池尾水原位土壤消纳研究

基于“厕所+三格化粪池+庭院消纳+菜园经济”模式,根据化粪池尾水在菜园不同距离土壤中的富集量,采集不施尾水处理（CK）、前段0~1.5 m（S1）、中段1.5~3.0 m（S2）和后段3.0~4.5 m（S3）菜园表层土壤样品,对土壤化学性质、酶活性和微生物多样性进行测定,探究农村三格化粪池尾水原位土壤消纳对蔬菜种植土壤环境的影响。相比于不施尾水处理,三格化粪池尾水经原位土壤消纳后,土壤pH值降低0.83~0.91,有机质含量提高29.6%~39.5%,全磷含量提高125.0%~171.4%;蔗糖酶（S-SC）活性提高157.0%~170.0%,过氧化氢酶（S-CAT）活性降低12.7%~19.0%,脲酶（S-UE）活性降低36.0%~43.4%（P<0.05）。土壤环境中真菌和细菌群落多样性（Shannon）及群落丰富度（Ace）显著提高（P<0.05）;尾水原位土壤消纳提高了红球菌属（Rhodococcus）、节杆菌属（Arthrobacter）、溶杆菌属（Lysobacter）及微枝形杆菌属（Microvirga）等有益菌的相对丰度,也提高了分枝杆菌属（Mycobacterium）、枝孢菌（Cladosporium）等致病菌的相对丰度。研究表明：三格化粪池尾水原位土壤消纳方式可提高庭院菜园土壤肥力和土壤微生物多样性,实现尾水资源化利用;然而也存在致病性微生物环境风险,因此需加强前端尾水的监测和无害化处理,为厕所污水处理技术的优化提供数据支撑,推广该模式对建设农村人居环境、改善农民生活品质具有重要意义。

Study on in situ soil absorption of tail water in a rural three-compartment septic tank

Soil samples were collected from treatments without tail water (CK) and at 0~1.5,1.5~3.0 m,and 3.0~4.5 m from septic tank tail water based on a "toilet+three-compartment septic tank+yard consumption+vegetable garden economy" model with different distances from vegetable garden soil.The soil chemical properties,enzyme activity,and microbial diversity were determined to explore the effects of in situ soil absorption of three-compartment septic tank tail water on the soil environment of vegetable plants.Compared with those of CK,the soil pH decreased by 0.83~0.91 and the organic matter and total phosphorus contents increased by 29.6%~39.5% and 125.0%~171.4%,respectively,after the three-compartment septic tank tail water was absorbed by the soil.The sucrase activity increased by 157.0%~170.0%,whereas the catalase and urease activities decreased by 12.7%~19.0% and 36.0%~43.4%(P<0.05),respectively.Moreover,the community diversity (Shannon) and community richness (Ace) of the soil fungi and bacterial communities significantly increased (P<0.05).The relative abundances of beneficial bacteria,including Rhodococcus,Arthrobacter,Lysobacter,and Microvirga,and pathogenic bacteria,including Mycobacterium and Cladosporium,increased after soil absorption of tail water.The combined results showed that the in situ soil absorption of the tail water of the three-compartment septic tank could improve the soil fertility and microbial diversity and realize the utilization of tail water resources.However,pathogenic microorganisms would pose an environmental risk.Therefore,it is necessary to strengthen the harmless treatment and monitoring of tail water and to provide scientific support for the optimization of toilet sewage treatment technology.The promotion of this model is important for the construction of rural living environments and for the improvement of farmers''life quality.