抚河南昌段底泥重金属污染特征研究

抚河南昌段是指水系从象湖将军闸流入南昌市至滕王阁排出入赣江这一段的河流。对抚河南昌段选择7个采样点采集底泥,分别采用微波消解和五步连续萃取法对抚河底泥中的重金属进行前处理,结合ICP-OES发射光谱仪测定重金属元素的含量。结果表明,抚河南昌段从上游到下游底泥重金属污染总体趋势是逐渐加重;As的平均值1079.835mg/kg,达国家土壤环境质量三级标准的35倍;个别采样点Cu的含量超过国家土壤环境质量二级标准,个别采样点Cr的含量比国家土壤环境质量三级标准的2倍还多。各采样点Cu、Mn的形态分布图很不一致,滕王阁采样点Cu的有机物结合态(S4)最高,占75.55%,Mn的铁锰氧化物结合态(S3)也较高,占50.51%;抚河桥样品Mn的可交换态(S1)最高,占74.68%;各采样点Cu的碳酸盐结合态(S2)都较低,不足20%。残渣态(S5)以将军闸30m(Cu)、司马庙立交桥(Mn)采样点较高,分别为45.40%,45.16%。抚河底泥可用于城市绿化施肥。

Contamination Characteristics of Heavy Metals of Fu River Sediments at Nanchang Segment

Sediment samples at 7 spots from Nanchang segment of Fu River which is inflowing into Nanchang City and discharging to Gan River were collected and pretreated separately by microwave digestion method and Tessier sequential chemical extraction procedure. Contents of heavy metals of samples were determined by inductively coupled plasma analysis. Results showed that general trend of heavy metals contamination in sediments of the River was aggravation gradually from upriver to downriver. Average concentration of As was 1079.835mg/kg, which was 35 times of Class III of national soil quality standard. Contents of Cu and Cr at individual sampling spot exceeded Class II and Class III soil quality standard respectively. Distributing maps of Cu and Mn modality of all sampling spots were not very identical, with the highest of organic matter species of Cu at Tengwang Pavilion, and the highest of exchangeable species of Mn at Fu River bridge.