污水灌溉对作物重金属含量的影响因素分析

针对污水灌溉对作物产生重金属污染的问题,在对现有研究成果整理的基础上,分析结果认为:土壤中黏土成分比的增大、土壤粒径的减小、土壤有机质成分的增加和土壤pH值的降低对土壤重金属有效态含量的升高有促进作用;在一定范围内,作物重金属含量与灌溉污水中重金属离子、阴阳离子浓度呈正相关关系,与污水pH呈负相关关系;粮食作物对重金属的富集能力顺序为水稻小麦玉米大豆,蔬菜作物为叶菜类花菜类根茎类果菜类;作物不同营养部位对重金属的累积大多服从根茎叶籽的规律。

Effect of Sewage Irrigation on Heavy Metal Content of Crops

To assess the potential impacts of sewage irrigation on crops heavy metal pollution ,this paper gets the following conclusion on the basis of existing research results :the available heavy metals content can be increased by the increase of clayey content and or‐ganic proportion and decrease of the soil particle size and soil pH value .At a certain range ,the crop heavy metal content is positively correlated with the concentration of heavy metal and anions and cations in sewage and negatively related with sewage PH value .Gen‐erally ,the order of the accumulation of heavy metals resulting from irrigation with sewage water from big to small for food crops is rice ,wheat ,corn ,and soybean ,and for vegetables crops is leaf vegetables ,cauliflower class ,rhizome ,fruit vegetable ;The accu‐mulation of heavy metals in crops vegetative parts is mostly in the following descending order as root ,stem ,leaf and seed .