摘要
针对规模化畜禽养殖业发达地区畜禽粪便引发的重金属和可溶性盐污染负荷重等问题,以杭州市为例,分析了杭州市各区县由畜禽粪便引起的氮、磷污染负荷.同时,通过空间分析与基于土壤盐分和重金属累积模型的模拟预警分析,评估了畜禽粪便农用过程中对温室土壤次生盐渍化和重金属累积的潜在影响.结果表明,杭州市畜禽粪便氮磷污染负荷分布不均,以建德市、萧山区、临安市污染最为严重,氮磷污染预警级别达到Ⅳ～Ⅵ级;所辖各市区的磷污染风险等级均高于或者等于各自的氮污染风险等级.若农田中施用畜禽粪便时以氮为指标,将可能造成磷素的累积和流失.施用畜禽粪便对温室土壤影响较大,畜禽粪便盐施肥量越高,土壤盐渍化和重金属累积的趋势越明显.在畜禽粪便中等盐分和重金属含量及中、高施肥量条件下(65～100t·hm-2,以干粪计),经过5a左右的累积,土壤盐渍化程度将有明显提高;经过4a左右的累积,重金属Cu、Zn的土壤环境质量将会从二级变为三级.
Heavy metals and salinization resulted from intensive livestock production have been significant environmental problems in breeding developed areas.Livestock manure-derived nitrogen and phosphorus loads in farmland of districts in Hangzhou were calculated respectively in this study.The main heavy metals and salt content in livestock manure samples were analyzed and the potential risk was evaluated by the methods of simulating prediction on the accumulation model of salt and heavy metal in soil.As a result,the nitrogen and phosphorus pollution load in Jiande,Xiaoshan and Linan districts were higher,and the alert levels were Ⅳ～Ⅵ.The alert levels of phosphorus in those districts were equal to or higher than the alert levels of nitrogen.It might lead to the risk of accumulation or loss of phosphorus when livestock manure was applied according to nitrogen quantity demanded of soil.It might result in the risk of salinization and heavy metal accumulation by the application of livestock manures in the greenhouse soil.With the middle level amount of salinity and heavy metals in livestock manure,and the high level application of livestock manure （65～100 t·hm-2 dry manure） in greenhouse soils,the salinization of soils would be remarkable in 5 years,and the environmental quality for soils （Cu,Zn） would reach level Ⅲ from level Ⅱ in 4 years.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第11期2562-2569,共8页
Acta Scientiae Circumstantiae
基金
国家水体污染控制与治理科技重大专项(No.2008ZX07101-006-04)~~
关键词
畜禽粪便农用
氮磷
重金属
土壤次生盐渍化
风险评估
livestock manures application
nitrogen and phosphorus
heavy metal
soil salinisation
risk evaluation
