煤矸石在复垦土壤中的利用方式对水稻重金属含量的影响

本文通过以煤矸石为填充材料的复垦土壤上种植水稻的盆栽实验,研究在土壤复垦过程中煤矸石的填充方式和配比浓度对水稻籽粒和秸秆中重金属含量的影响。研究结果表明:在设定的煤矸石配比浓度范围内,水稻籽粒和秸秆中的重金属含量,都随煤矸石配比浓度的增加而增加,其中煤矸石配比浓度为40%时,增幅最大F元素在籽粒中的含量为0.921 mg/kg,是空白的1.12倍;在秸秆中的含量为9.064 mg/kg,是空白的4.19倍;煤矸石的两种填充方式下,水稻籽粒和秸秆中的重金属含量,大多呈现掺混式的大于垫底式的,其中煤矸石配比浓度为10%时,籽粒中差值最大的的F元素,含量相差了0.128 mg/kg,前者是后者的1.29倍;配比浓度为40%时,秸秆中差别最大的As元素,含量相差了0.352 mg/kg,掺混式的高于。垫底式的1.87倍。污染指数评价结果显示:籽粒中的重金属综合污染指数,皆小于1,未受到重金属污染,但在配比浓度为40%时,Hg的单项污染指数大于1,籽粒受到Hg的污染;秸秆的综合污染指数在1到3之间,重金属重污染程度严重,应对产出的秸秆妥善处理,以免对生态环境造成新的污染。

The Influence of Coal Gangue Utilization for Reclaim Farmland on the Concentrations of Heavy Metals in Rice

The influence of fill patterns and coal gangue compounding concentrations for reclaimed farmland soil on the concentrations of heavy metals in rice grain and straw were studied in this paper by using pot experiments. Results show that under both fill patterns within experiment coal gangue concentration, concentrations of heavy metals in rice grain and straw increase with increasing concentration of coal gangue. When coal gangue concentration is 40%, the concentrations of fluorine in grain and straw are 0.921 and 9.064 mg/kg, 1.12 and 1.19 times of the reference blank sample, respectively. Under the same compounding concentration, the concentrations of heavy metals within grain and straw of mixing fill pattern are higher than those of stacking fill pattern:Under compounding concentration of 10%, the difference of fluorine concentration between the two fill patterns is 0.128 mg/kg, which is of the largest difference in grain; while in straw, the largest difference in concentration exists in arsenic:under compounding concentration of 40% the difference is 0.352 mg/kg. The contamination index evaluation shows that rice grain are not contaminated by heavy metals for the heavy metal composite contamination indexes of grain are all lower than 1; however under the compounding concentration of 40%, the contamination index of mercury is higher than 1.The composite contamination indexes of straw are between 1 and 3, indicating that rice straw has suffered heavy metal contamination, and should be treated carefully, in order to avoid secondary pollution.