保定市郊灌溉水质分析及灌区蔬菜质量评价

随着市郊农业快速发展,灌区蔬菜安全问题备受重视。以保定市环境监测站2008年监测数据为背景值,比对农田灌溉水质标准以及蔬菜中的污染物含量相关指标,并采用综合指数法,对污水河所含的污染物及相关蔬菜污染程度进行了分析评价。结果表明:保定市污水河所排污水的CODCr、Cd、Zn和挥发酚的实际含量,均超过国家农田灌溉水质标准所限定的蔬菜作物最高含量。因此,保定市排污河属中度污染水质,已不适宜直接作为农田灌溉用水。保定市郊污灌区蔬菜中Cd的污染程度较重,检出超标为75.0%。在所检测的几个蔬菜中,大葱、菜花、芥菜、莴笋、白萝卜等综合污染指数低于1.0,属于安全等级,大白菜、小油菜、芹菜、菠菜、香菜综合污染指数大于1.0小于2.0,属于轻度污染,其中香菜和大白菜的综合污染指数较大(1.20～1.50)。保定市郊污灌区蔬菜中Pb、Cd、Zn等综合因子污染评价,叶菜类均达到轻度污染程度,综合污染指数(P)表明,大白菜、小油菜、芹菜、菠菜、香菜均有轻度污染。

Irrigation water quality analysis and quality evaluation of the irrigated vegetables in Baoding suburb

With the rapid development of suburban agriculture,irrigated vegetable security issues have been paid much attention.Based on the monitoring data for background value of Baoding environmental monitoring station in 2008,the content of vegetable pollutants and the level of contained pollutants in the sewage river were analyzed by applying the method of comprehensive pollution indexes,according to the farmland irrigation water quality standards and the vegetable pollutant content related indexes.The results showed that the actual contents of sewage water CODCr,Cd and Zn in the Baoding sewage water river together with volatile phenol were all found over the national irrigation water quality standards concerning the highest allowed content in vegetable crops.Therefore,Baoding sewage water river is ranked as moderate pollution water quality,and the water is not suitable for direct irrigation of suburban sewage vegetables.The Cd pollution level of Baoding suburban wastewater irrigation vegetables is relatively heavy,detection overweight is 75.0%.In the tested vegetables,the comprehensive pollution index of green Chinese onion,cauliflower,mustard,asparagus lettuce,turnip was less than 1.0,and belonged to the safety level,Chinese cabbage,small rape,celery and spinach,parsley was higher than 1.0but lower than 2.0and belonged to the light pollution level,and the index for parsley and Chinese cabbage was 1.20-1.50.According to the evaluation of Pb,Cd,Zn and the comprehensive factor pollution for Baoding suburban wastewater-irrigated vegetables,leaf vegetables are at the mild pollution level,and comprehensive pollution index(P) shows that Chinese cabbage,small rape,celery and spinach,parsley are under mild pollution.