不同水期嘉陵江北温泉段表水中COD的变化特征

On COD Variations of Surface Water in Beiweiquan Section,Jialing River during Different Water Periods

为进一步了解河流表水中化学需氧量(COD)在丰、平、枯3个水期的变化特征,于2011年7月-2012年3月连续监测了嘉陵江北温泉段水中的COD含量,分析了COD与水质参数之间的相关关系.结果表明,嘉陵江北温泉段表水中COD随水期呈现明显的变化,大小顺序表现为丰水期、平水期和枯水期,由面源污染带入的有机污染比较严重.同步监测的水质参数也随水期呈现明显的变化,温度(T)和pH变化大小顺序表现为丰水期、平水期和枯水期,溶解氧(DO)由小到大为丰水期,平水期和枯水期,氧化还原电位(Eh)由小到大为丰水期、枯水期和平水期.Pearson相关分析发现,COD与水温和DO分别呈极显著的正相关和极显著的负相关关系,而与pH和Eh分别呈微弱的正相关和负相关关系.

For further understanding of the COD variations in surface water of river during different water periods,the contents of COD in Beiwenquan section,Jialing River,have been continuously monitored from July,2011 to March 2012,and the correlations between COD contents and water quality parameters also been analyzed.It has been found that COD contents in this section shows obviously variations in accordance with an order of high-flow period,mean-flow period,and low-flow period from high to low,which indicates that non-point organic pollutants are the major pollution resource.Moreover,the water quality parameters with simultaneous measurement also shows obviously variation in accordance with an order of high-flow period,mean-flow period,and low-flow period from high to low for T and pH,and with an order of high-flow period,mean-flow period,and low-flow period from low to high for dissolved oxygen（DO）,and with an order of high-flow period,low-flow period,and mean-flow period from low to high for redox potential（Eh）.Pearson correlation analysis has been found that COD shows significantly positive correlation and negative correlation with T and DO,while weak positive correlation and negative correlation with pH and Eh,respectively.