黄河水的COD值能够真实反映其污染状况吗?  

IS COD A SUITABLE PARAMETER TO EVALUATE THE WATER POLLUTION IN THE YELLOW RIVER?

作　　者：陈静生[1] 何大伟[1] 张宇[1] 

机构地区：[1]北京大学环境学院,北京100871

出　　处：《环境化学》2003年第6期611-614,共4页Environmental Chemistry

基　　金：国家重大基础发展规划项目(G1 9990 43 60 3 )

摘　　要：本文表述了“黄河水的COD值不能真实反映其水污染程度的见解” ,黄河水中泥沙的存在大大提高了COD和高锰酸盐指数的测定值 ,增大了水质监测结果的随机性和不确定性 ,加大了判断水污染程度的复杂性和难度 .但我们与其他学者在认识上有明显的差异 .他们认为 ,泥沙含有或吸附了耗氧有机物质 ,不能忽视其作为面源污染物的影响 .而我们认为 ,黄河泥沙中的有机质是无害的稳定性极好的天然腐殖质类物质 ,它在COD监测方法规定的高温、强酸性、强氧化剂条件下 ,可被氧化而耗氧 ,但在正常的地表条件 (低温、低压、中性 )下 ,其被氧化而耗氧的过程极为缓慢和有限 ,不会对水体产生污染危害 .我们的认识是 ,不应将黄河泥沙中的天然腐殖质与通常观念上的耗氧有机污染物混为一谈 .This paper pointed out that the COD values detected in the non polluted reaches of the Yellow river are often as high as several ten,hundreds or even thousands mg·l -1 nearly equal to the pro duct of the sediment content in the river water and the organic matter content in sediments of the ri ver ,Authors considered that most of organic matters in sediments are nutural humic substances that are rather stable.In spite,natural humic substances could be oxidized under the conditions of high temperature,strong acidity and strong oxidant when using the regular method to test the COD in the Yellow river water,and make up of the principal part of the COD in the river water,the oxidation process of these substances,however,is quite slow and limited in natural conditions ,and will not produce contamination to the river water.COD is not a suitable index to reflect and evaluate the water quality of a river with excessive silt;better water quality parameter is to be found to reflect and evaluate the real polluting situation caused by oxygen demanding organic substances in the Yellow river.

关 键 词：黄河 水污染 COD 化学耗氧量 高锰酸盐指数 水质监测 天然腐殖质 

分 类 号：X832[环境科学与工程—环境工程] X131.2