粉煤灰土壤主所产蔬菜的有害元素含量变化的环境意义

利用南京第二热电厂湿排的粉煤灰，进行了改良蔬菜土壤的试验，并对试验用的粉煤灰，不同施灰量的土壤及所产蔬菜的３８个样品的有害元素和放射性元素含量进行了系统的测定。结果表明：这些元素在土壤中的含量与粉煤灰施用量无明显相关性；在本次试验范围内施用粉煤灰没有造成土壤的污染，其所产蔬菜的这些元素含量也均低于国家卫生标准限值，食用是安全的。

THE CONTENT VARIATION OF HARMFUL ELEMENTS IN SOILAND VEGETABLES IN FIELD AMELIORATED WITH FLYASH AND THEIR ENVIRONM ENTAL SIGNIFICANCE

How to deal with the coal fly ash drained from the power plants is a crucial problem related to the sustained development of the whole society. Soil amelioration with fly ash is an important approach to comprehensive utilization of the latter However，fly ash contains harmful elements such as Cd, Hg, As, Cr, Pb, Ni, U, Th. How do these elements affect soil and vegetables? Is there an enrichment of harmful elements? The experiment of vegetable and soil amelioration with fly ash from the Second Power Plant in Nanjing has been performed. The applied amount of fly ash was of four levels: 0t/hm2, 15t/hm2, 30t/hm2 and 45t/hm2. The contents of harmful elements of 38 samples, including fly ash rumples, soil samp1es applied with different amount of fly ash and vegetable samples grown in the soil were analyzed. The results show that the contents of harmful elements in the soil and vegetable are lower than the lever stipulated by the state standards about the soil and vegetables. There does not exist a positive correlation between the contents of the harmful dements and the applied amount of fly ash. Consequently, these vegetables are eatable as common vegetables. It is safe to use the fly ash drained from the Second Power Plant in Nanjing into the soil with an amount in the range of present experiment, namely not higher than 45t/hm2