德州灌区地表水中磷的空间分布与来源研究

Distribution and Sources of Phosphorus of Surface Water in Dezhou Irrigated District, China

地表水中磷污染与人类健康及水体生态环境密切相关。以黄河下游德州引黄灌区为例,采集研究区内主要水系的33个地表水样,并于现场测定pH值和电导率（EC）等指标,分析了地表水中总磷（TP）、正磷酸盐（P-ortho）、溶解性总磷（TDP）和溶解性正磷酸盐（P-D-ortho）的含量及污染状况,为引黄灌区地表水管理提供科学依据。实验结果表明,总磷的含量为0.03~5.39 mg.L-1,正磷酸盐的含量为0~5.10 mg.L-1,溶解性总磷的含量为0.01~2.19 mg.L-1,溶解性正磷酸盐的含量为0~1.73 mg.L-1。EC、总磷、正磷酸盐、溶解性总磷以及溶解性正磷酸盐的含量均存在明显的空间差异。各河流之间相比,EC空间差异不大,但是每条河流内部都存在较大的变异性;4种形态磷含量的空间分布不均,漳卫新河各形态磷的含量均高于其他河流;其次为徒骇河,而德惠新河4种形态磷的含量均最低。此外,对悬浮物中吸附的磷进行了空间分析,受河流含沙量以及工农业生产等因素的影响,其空间分布差异明显。总磷受人类活动影响增强而增加,灌区各水系均有不同程度的污染,根据我国地表水环境质量标准（GB 3838—2002）,整个灌区有84.9%的样点达到III类（0.10.4 mg.L-1）的样点达到77.8%。

The phosphorus contamination of surface water is closely associated with human health and change of water ecological environment.In this study,33 surface water samples were collected in the Dezhou Irrigated District located in the lower reaches of the Yellow River.pH,water temperature,and electrical conductivity were analyzed in situ.The concentrations of total phosphorus(TP),orthophosphate(P-ortho),dissolved total phosphorus(TDP) and dissolved orthophosphate(P-D-ortho) were determined by the method of phosphorus determination using Semi-Automated Colorimetry(Environmental Protection Agency,EPA).This study provided a scientific basis for the management of the surface water in the Yellow River Irrigated district.Results indicated that the concentrations of TP,P-ortho,TDP,and P-D-ortho were in range of 0.03~5.39 mg·L-1,0~5.10 mg·L-1,0~1.73 mg·L-1 and 0.01~2.19 mg·L-1,respectively.EC,TP,P-ortho,TDP and P-D-ortho had obviously spatial variations.Spatial variations of EC were found within each river.The spatial distributions of the four forms of phosphorus concentrations had significantly differences.The concentrations of phosphorus in the Zhangweixin River were the highest,followed by Tuhai River,and lowest in Dehuixin River.Moreover,the spatial distributions of phosphorus in suspended matter were affected by suspended matter concentration as well as industrial and agricultural productions.TP was affected by human activities extremely,and water bodies had different levels of contamination in the Dezhou Irrigated District.According to the Surface Water Environment Quality Standard of China(GB 3838—2002),about 84.9% of the samples have reached Class Ⅲ(0.1<TDP≤0.2 mg·L-1) or exceeded water quality standards in the whole irrigated area.The concentrations of phosphorus was the highest in the Zhangweixin River,about 77.8% of the samples have reached Class V(0.3<TDP≤0.4 mg·L-1) or exceeded class V(TDP>0.4 mg·L-1).