普者黑流域畜禽养殖型农村沟渠底泥磷形态分布特征及风险评价

Distribution Characteristics and Risk Assessment of Phosphorus Speciation in Livestock Rural Ditch Sediments of Puzhehei Basin

为揭示普者黑流域畜禽养殖型农村沟渠底泥磷形态的分布特征以及磷污染风险,以云南省丘北县八道哨村为研究对象,分析其沟渠底泥磷形态的含量。结果表明,全磷(TP)含量为973.04~3195.50 mg kg-1,空间分布呈沟渠污水汇集处(集合点)>各家各户排污口(分散点);各形态无机磷(IP)含量大小依次表现为钙结合态磷(Ca-P)>铁铝氧化态磷(Fe/Al-P)>可还原态磷(RSP)>弱吸附态磷(labile-P),其生物可利用性依次增强;对生态环境磷污染风险贡献由大到小依次为Fe/Al-P>labile-P>RSP>Ca-P。方差分析结果表明,w(TP)在集合点和分散点间存在显著差异性;不同分散点之间各形态磷含量的空间分布均存在显著性差异。磷污染风险评价结果表明,畜禽养殖型农村集合点底泥的磷污染风险比分散点高;沟渠底泥整体磷污染风险属于中度污染。研究结果可为畜禽养殖型农村环境污染综合整治和污染风险评价提供理论依据。

In order to reveal the distribution characteristics of phosphorus （P） speciation and the P pollution risk of livestock rural ditch sediments in Puzhehei basin, the Badaoshao countryside in Yunnan Province was selected as research site and its content of P speciation in ditch sediment was analysed. The results showed that the contents of total P （TP） ranged from 973.04 to 3195.50 mg kg^-1. Its spatial distribution was higher in the ditch sewage collection points （collection points） and lower in each family sewage ouffall （dispersion points）. The content of each speciation of inorganic P （IP） decreased as the following sequence： Ca-P 〉 Fe/Al-P 〉 RSP 〉 labile-P and their biological availability were increased in turn. The contribution of P pollution risk of ecological environment decreased as the following sequence： Fe/Al-P 〉 labile-P 〉 RSP 〉 Ca-P. The results of ANOVA showed that the content of TP exhibited the significant differences between the collection point and dispersion point. There were significant differences in the spatial distribution of different P speciation among different dispersion points. The results of P pollution risk assessment showed that the pollution risk of the sediment in collection points was significantly higher than that in dispersion points. The pollution risk level of P in ditch sediment was moderate pollution. The results of this study would provide a theoretical basis for the comprehensive improvement of rural environmental pollution and the risk assessment of the pollution in the livestock countryside.