白马湖西岸入湖河流污染特征解析

通过对2015—2016年监测数据分析发现,白马湖西岸入湖河流受氮磷污染严重。为进一步了解白马湖西岸入湖河流污染特征,及其对白马湖水质的影响,于2016年11月对白马湖西岸8条主要入湖河流和湖水进行采样,测定了氮磷浓度及其形态等多个指标。结果表明:8条主要入湖河流污染程度为花河>浔河>往良河>大荡河>桃园河>山阳河>草泽河>丰产河;入湖河流受氮污染影响严重,TN浓度为1.41~9.12 mg/L,严重超过GB 3838—2002《地表水环境质量标准》Ⅲ类标准,溶解性总氮(TDN)浓度占TN的65.61%~99.30%,是入湖河流中氮的主要形态;入湖河流受磷污染总体较轻,除浔河TP浓度超地表水Ⅲ类标准0.2倍外,其余7条入湖河流均达到Ⅱ~Ⅲ类标准,水体中溶解性总磷(TDP)浓度占TP的53.03%~96.70%,是入湖河流中磷的主要形态。聚类分析结果表明:入湖河流分为三类,花河单独聚为一类,往良河和浔河聚为一类,大荡河、丰产河、桃园河、山阳河和草泽河聚为一类。因子分析结果表明:花河、往良河和浔河水质受氮污染影响较显著;往良河和浔河水质主要受磷污染影响;往良河、大荡河和山阳河水质受有机物污染影响。随着与入湖河口距离的增加,白马湖西岸受纳水体TN、N H 4 + -N、TP浓度及CODMn等水质指标呈降低趋势,说明白马湖西岸入湖河流对其水质有直接影响,入湖河流污染物输入是其水质下降的重要原因。

Analysis of pollution characteristics of inflow rivers of Baima Lake west bank

Based on the analysis of the monitoring data from 2015 to 2016, it was found that the inflow rivers in the west bank of Baima Lake was seriously polluted by nitrogen and phosphorus. In order to further understand the pollution characteristics of the inflow rivers of Baima Lake west bank and its impact on the water quality of Baima Lake, eight main inflow rivers were sampled in November, 2016. The concentration and formation of nitrogen and phosphorus were measured. The results showed that the pollution level of the eight inflow rivers was in the order of Hua River> Xun River> Wangliang River> Dadang River> Taoyuan River> Shanyang River> Caoze River> Fengchan River. The eight inflow rivers were seriously polluted by nitrogen. TN ranged from 1.41 to 9.12 mg/L, exceeding the standard level seriously. TDN which accounted for 65.61%-99.30% of TN was the main form of nitrogen in the inflow rivers. The pollution level of phosphorus was comparatively lower, the concentration of TP in Xunhe River exceeded Class Ⅲ of the Environmental Quality Standard for Surface Water by 0.2 fold, while the other seven rivers maintained at the Class Ⅱ-Ⅲ. The TDP accounted for 53.03%-96.70% of TP, which is the main form of phosphorus in the inflow rivers. The eight inflow rivers could be divided into three categories by the cluster analysis, with Hua River alone as one category, Wangliang River and Xun River as the second category, and Dadang River, Fengchan River, Taoyuan River, Shanyang River and Caoze River belonging to the third category. The results of factor analysis showed that the water quality of Huahe River, Wangliang River and Xunhe River was significantly affected by nitrogen pollution, the water quality of Wangliang River and the Xun River was mainly affected by phosphorus pollution, while that of Wangliang River, Dadang River and Shanyang River was affected by organic pollution. With the increase of the distance from the lake inflow, the concentration of TN, ammonia nitrogen, TP and permanganate index in Baima Lake west bank decreased, indicating that the inflow rivers had direct impact on the water quality of the lake, and the input of pollutants of inflow rivers should be the important reason for the decline of the water quality of Baima Lake.