污泥和粉煤灰配施对土壤物理性状和汞积累的影响

Effect of Combination of Sludge with Flyash on Soil Physical Properties and Accumulation of Mercury

本文采用盆栽试验方法研究了污泥、粉煤灰配合施用对土壤物理性质、冬小麦生长发育的影响．并探讨了粉煤灰对污泥中汞污染的防治途径．结果表明：施用污泥后提高了土壤紧实度，增大了＞０．０５ｍｍ和０．０１ｍｍ微聚体含量及团聚度．总孔隙度呈减少趋势，特别是引起了＞５０μｍ的大孔隙减少；而粉煤灰施用后则降低了土壤紧实度，增大了土壤总孔降度，特别是＞５０μｍ微团聚体含量及团聚度的增加．因此，污泥和粉煤灰配施改善了土壤结构，协调了土壤孔隙状况．随着污泥用量增加，土壤汞含量明显增加，并呈极显著的正相关，但配施粉煤灰后并随粉煤灰用量加大，土壤汞含量呈降低趋势，说明粉煤灰具有减轻和缓解污泥引起的土壤．壤汞积累的作用．污泥和粉煤灰配合施用量分别为ｅｄ０００ｋｇ／ｈｍ２和２２５００ｈｇ／ｈｍ２时冬小麦产量最高，校对照增产２０．４％，当超过此施用量时又抑制了小麦生长，降低了籽粒产量．

This article was conducted by using a pot-culture method to study the effect of the combination of sludge with flyash on soil physical properties and the growth of winter wheat,especially to inquire into the prevention and cure of mercury polution in sludge.The result showed that the applied sludge increased soil bulk densith and >0.05mm and <0.01mm microaggregate content and degree of aggregation, decreased toeal porosity, especially caused >500μm Pore's decreasing. However, the applied flyash decreased soil bulk density and increased soil total porosity, especially had a increasing trend to > 50μm pore, simultaneously increased >0.05mm microaggregate content and degree of aggravation. So the combination of sludge with flyash improved soil structure, regulated soil pore regime with the increasing of sludge added, the amount of mercury accumulated in soil increased apparently and were positively correlated with the amount of sludge added. As flyash was added in sludge, the amount of mercury in soil decreased, it indicated that flyash could prevent mercury in sludge from polution.when the combination quantity of sludge with flyash was 60000 kg/ha and 225000kg/ha respectively,the output of winter wheat was highest, it increased by 20.4 per cent as compared with comparison. But, beyond the applied quantity, it prevented the growth of winter wheat and decreased the output of wheat grain.