摘要
构建处理不同负荷养殖废水的绿狐尾藻人工湿地,采集湿地表层(0~5cm)、中层(5~10cm)和底层(10~20cm)底泥样品,测定TP及有机磷含量,并用五步化学分级提取法将无机磷逐级提取为水溶性磷、铝结合态磷(Al-P)、铁结合态磷(Fe-P)、闭蓄态磷(O-P)和钙结合态磷(Ca-P),对比了各形态无机磷水平和垂直分布差异。结果表明,绿狐尾藻人工湿地表层底泥TP质量浓度在167~965mg/kg,其中有机磷占TP的66.0%(质量分数,下同)~79.2%。各形态无机磷的含量排序为:O-P>Fe-P>Ca-P>Al-P>可溶性磷。不同形态无机磷随着底泥深度的增加变化不同,总体来看,从表层到中层,Al-P、Fe-P和Ca-P含量呈现降低趋势,中层到底层无明显变化规律;低负荷湿地中,O-P含量随深度增加逐渐降低,而在中、高负荷湿地中O-P含量随深度增加逐渐增加。相关分析结果显示,Al-P、Fe-P、O-P含量与底泥pH和溶解性有机碳(DOC)呈显著或极显著正相关,说明磷在底泥中的行为易受底泥pH和DOC影响。
The surface-flow constructed wetland planted with Myriophyllum aquaticum was established to treat livestock wastewater of different loads. The surface （0-5 cm）, middle （5-10 cm） and bottom （10-20 cm） layer sediments were collected,and total phosphorus （TP） and organic phosphorus in these sediments samples were analyzed. The inorganic phosphorus was divided into soluble phosphorus, aluminum bound phosphorus （A1-P）, iron bound phosphorus （Fe-P）,occluded phosphorus （O-P） and calcium bound phosphorus （Ca-P） using the 5 steps chemical fractionation method. The horizontal and vertical distribution of inorganic phosphorus fractionations were analyzed and compared. The results showed that the contents of TP in the surface sediments ranged from 167 to 965 mg/kg, and organic phosphorus accounted for 66.0^-79.2~/0 of TP concentration. The order of the average contents of inorganic phosphorus forms was O-P〉Fe-P〉Ca-P〉Al-P〉soluble phosphorus. The forms of inorganic phosphorus varied with the depth of sediments. Generally,Al-P,Fe-P and Ca-P contents decreased from surface sediment to middle layer sediment,while there was obvious changing rule from middle layer to bottom layer sediment. O-P contents gradually reduced in the light loaded constructed wetlands but increased in the medium and high loaded constructed wetlands. The correlation analysis showed that the concentrations of Al-P, Fe-P and OP had a significant or highly significant positive correlation with sediment pH and dissolved organic carbon, suggesting that the three forms of phosphorus were susceptible with sediment pH and dissolved organic carbon.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2017年第10期1082-1087,共6页
Environmental Pollution & Control
基金
国家重点研发计划项目(No.2016YFE0101100)
中国科学院先导专项(No.XDB15020401)
关键词
磷形态
底泥
垂直分布
人工湿地
绿狐尾藻
phosphorus fractionation
sediment
vertical distribution
constructed wetland
Myriophyllurn aquaticum
