摘要
对浙江、山东、安徽三省部分大型热电厂粉煤灰的采样分析表明 :粉煤灰中主要放射性成分为238U、232Th和40K ,比活度范围分别为75～284Bq/ 、96～164Bq/ 和120～382Bq/ 。粉煤灰农田施用模拟试验表明 :当施用量达525t/hm2时 ,土壤中天然放射性核素238U、232Th和226Ra的比活度分别是对照的2.44倍、1.39倍和1.88倍 ;生产的稻谷和玉米籽中三种核素的比活度与对照无明显差异 ,对作物的食用安全性影响不明显。粉煤灰使用地采样分析结果表明 :农田施用硅肥不会造成生产的稻谷和玉米籽中的天然放射性核素的比活度超过国家标准 ;而在纯粉煤灰上种植生产的作物果实中 238U、232Th。
Ten coal ash samples from the electric power plants of Zhejiang,Shandong and Anhui were measured by HPGE γspectrometer analyzer respectively.The results showed that the main radioactive nuclides in ash are 238U,232Th and 40K.The specific activities of 238U,232Th and 40K were from 75Bq/to 284Bq/,96Bq/to 164Bq/and 120Bq/to 382Bq/respectively.The results of simulated experiment applied coal ash showed that:The specific activity of 238U,232Th and 226Ra in the treated soil were 2.44,1.39 and 1.88 times higher than those in control soil respectively when the coal ash was applied up to 525t/hm2.The specific activity of three nuclides in paddy and maize seed grown in soil with coal ash were similar to that in control soil.The effect of edible security is not evident.The results of sampling analyze from the farmland used coal ash showed that:The specific activity of three nuclide in paddy grown in soil with of silicon fertilizer did not exceed security standard.However the specific activity of 238U,232Th and 226Ra in maize seed and eggplant grown in pure coal ash exceeded security standard.
基金
农业部"九五"重点项目资助
