截污后晋江水质季节变化分析与评价

Analysis and Evaluation of Seasonal Variation of Water Quality in Jinjiang River After Sewage Interception

通过统计2019年晋江石砻断面水质周报数据,分析该断面水质指标季节变化,并用单因子指数法评价其水质。结果表明:pH值全年变化范围为6.68~7.54,季节均值顺序为秋季<冬季<春季<夏季;DO全年变化范围为5.0 mg/L~9.7 mg/L,春冬季高于夏秋季;I_(Mn)全年变化范围为1.5 mg/L~3.4 mg/L,春夏季略高于秋冬季;NH_(3)-N全年变化范围为0.08 mg/L~0.51 mg/L,表现为春冬季高,夏秋季低;TP全年变化范围为0.042 mg/L~0.169 mg/L,表现为春季最高,夏冬季次之,秋季最低;Cr(Ⅵ)全年稳定在0.002 mg/L。单因子评价法显示,晋江总体符合Ⅲ类水质标准;使用t检验法发现,TP与NH_(3)-N显著相关,可能是由于二者受到相同污染源的影响所致。

Based on water quality weekly report data in Shilong section of Jinjiang river in 2019,the seasonal variation of water quality index was analyzed,and the water quality was evaluated by single factor index method.The results showed that the annual variation range of pH value was from 6.68 to 7.54,and the order of seasonal mean value was autumn<winter<spring<summer.The annual variation of DO ranged from 5.0 mg/L to 9.7 mg/L,which was higher in spring and winter than in summer and autumn.The annual variation range of I_(Mn) was from 1.5 mg/L to 3.4 mg/L,which was slightly higher in spring and summer than in autumn and winter.The annual variation range of NH_(3)-N was from 0.08 mg/L to 0.51 mg/L,which was higher in spring and winter than in summer and autumn.The annual variation range of TP was from 0.042 mg/L to 0.169 mg/L,which was the highest in spring,followed by summer and winter,and the lowest in autumn.The concentration of Cr(Ⅵ)was stable at 0.002 mg/L throughout the year.According to single factor evaluation method,the water quality of Jinjiang river met classⅢwater quality standard.TP was significantly correlated to NH_(3)-N by t test because they might be affected by the same pollution source.