稻田消解沼液工程措施的水环境风险分析

发布时间：2018-04-10 11:28

本文选题：环境控制 + 氮　；参考：《农业工程学报》2016年05期

【摘要】：为研究稻田消解沼液的能力及消解沼液过程中潜在的水体环境污染风险,该文通过田间定位试验,采取工程措施,监测并分析了稻田主要生育期消解沼液过程中田面水及不同深度下渗水总氮、铵态氮和硝态氮质量浓度变化情况。结果表明:1)稻田消解沼液的关键时期是施灌后的前3 d,总氮降解幅度达46.67%~78.36%,铵态氮降解幅度达47.52%~85.27%,且穗肥期消解速率大于基蘖期。施灌后3 d内若产生径流造成周边水体富营养化的环境风险较大,可采取封闭大田排水口或增加小区田埂高度5~10 cm等田间工程措施,控制地表径流产生量和产生时间,确保安全消解,实现农业面源污染源头减量减排。2)沼液消解量在200%BS处理(沼液氮量为常规施肥氮量的2倍,即沼液量705.88 t/hm2)以上,基蘖期和zB肥期对周边水体潜在的污染风险均高于常规施肥处理,100%BS处理(沼液氮量为常规施肥氮量的1倍,即沼液量352.94 t/hm2)与常规施肥处理相比潜在的环境污染风险稍低。因此,稻田工程措施消解沼液应采取少量多次的消解方式。3)稻田工程措施消解沼液对下渗水的污染风险主要集中在基蘖期,以铵态氮污染风险为主,硝态氮污染风险较小,污染程度因下渗水深度不同而有所差异。研究表明基蘖期稻田每次沼液消解量应控制在211.76 t/hm2以内,穗肥期稻田消解沼液能力较强,污染风险较小,单次消解量低于423.53 t/hm2在该试验的一个稻米生长周期内可视为安全的。该研究结果可为稻田沼液安全消解技术及农业面源污染源头减量减排技术提供理论支撑。
[Abstract]:In order to study the capacity of digesting biogas liquid in paddy field and the potential water environment pollution risk in the process of digesting biogas liquid, this paper takes engineering measures through field location test.The changes of total nitrogen, ammonium nitrogen and nitrate concentration in surface water and water at different depths during the digestion of biogas liquid in the main growth stages of rice field were monitored and analyzed.The results showed that the key stage of digesting biogas liquid in rice field was the first 3 days after irrigation, the degradation range of total nitrogen was 46.67 and 78.36, the degradation range of ammonium nitrogen was 47.52 and 85.27, and the rate of digestibility in panicle and fertilizer stage was higher than that in tillering stage.If the environmental risk of eutrophication caused by runoff within 3 days after irrigation is great, the field engineering measures such as closing the drainage outlet of the field or increasing the height of the ridge of the plot by 5 ~ 10 cm can be taken to control the amount and time of the surface runoff.In order to ensure safe digestion, the amount of biogas liquid digested by 200%BS is more than 2 times that of conventional fertilization, that is, the amount of biogas liquid is 705.88 t / hm ~ (2), that is, the amount of biogas liquid is 705.88 t / hm ~ (2) when the amount of biogas liquid is 705.88 t / hm ~ (2).The potential pollution risk of basal tillering stage and ZB fertilizer stage to the surrounding water body was higher than that of the conventional fertilization treatment of 100BS (the amount of biogas liquid nitrogen was twice as much as that of the conventional fertilization nitrogen, that is, the amount of biogas liquid was 352.94 t / hm ~ 2) and the potential environmental pollution risk was slightly lower than that of the conventional fertilization treatment.Therefore, a small amount of digesting biogas liquid should be adopted in paddy field engineering measures. 3) the pollution risk of digesting biogas liquid to the next seeping water is mainly concentrated in the tillering period, the main risk is ammonium nitrogen pollution risk, and the nitrate nitrogen pollution risk is relatively small.The degree of pollution varies with the depth of water seepage.The results showed that the digestibility of biogas liquid should be controlled within 211.76 t/hm2, the capacity of digesting biogas liquid in rice field at panicle and fertilizer stage was stronger and the risk of pollution was small. The amount of digestibility less than 423.53 t/hm2 could be regarded as safe in one rice growth cycle of this experiment.The results of this study can provide theoretical support for the technology of safe digestibility of biogas liquid from paddy field and the technology of reducing emission from agricultural non-point source pollution source.
【作者单位】：江苏省农业科学院农业资源与环境研究所江苏省农业科学院循环农业研究中心;江苏省农业环境监测与保护站;
【基金】：国家科技支撑计划项目(2012BAD14B12) 国家水体污染控制与治理科技重大专项(2012ZX07101004) 江苏省农业科技自主创新资金项目(CX(14)2106) 江苏省农业三新工程项目(SXGC[2015]291)
【分类号】：X82;S511

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