蜂窝煤灰渣对酸性和石灰性污染土壤中重金属的稳定研究

本研究的目的是探讨不同洗涤蜂窝煤灰渣在不同酸碱性土壤中对重金属的稳定效果.在酸性的淳安土壤(铅、镉、铜、锌污染)和石灰性的济源土壤(铅、镉污染)中以4%用量加入灰渣,培养60 d后测定土壤性质.结果表明,灰渣对淳安土壤pH和EC值的增加效果要大于对济源土壤的影响.原灰渣、硫酸洗灰渣和盐酸洗灰渣加入淳安土壤均可显著降低土壤DTPA提取态铅、镉、铜和锌的含量(p0.05),灰渣对济源土壤DTPA提取态重金属的含量影响较小.对于济源土壤,硫酸洗和盐酸洗灰渣与磷酸盐结合施用后土壤DTPA-Pb含量分别下降20.9%和33.1%.对于淳安土壤,加入3类灰渣后土壤DTPA-Pb含量下降26.8%~41.8%;对于淳安土壤,不论是单独施用还是与磷酸盐结合施用,硫酸洗灰渣对铜、锌稳定效果均强于盐酸洗灰渣.以上结果说明,蜂窝煤灰渣在酸性土壤中对重金属有更强的稳定作用,硫酸洗灰渣和盐酸洗灰渣对土壤重金属的稳定作用存在差异.

Immobilization of heavy metals in acid and calcareous soils with honeycomb briquette combustion residue

A soil incubation experiment was conducted to investigate the effect of honeycomb briquette combustion residue (HBCR) amendment on the immobilization of heavy metals in calcareous and acid soils. The acid Chun''an soil (with elevated levels of Pb, Cd, Cu and Zn) and calcareous Jiyuan soil (with elevated levels of Pb and Cd) were amended with raw, sulfuric acid-, and hydrochloric acid-washed HBCR at 4%, respectively, and incubated for 60 d. Soil analysis indicated that amendment with all three HBCRs increased soil pH and EC more in the Chun''an soil than in the Jiyuan soil. The HBCR amendment significantly reduced the concentrations of DTPA-extractable Pb, Cd, Cu and Zn in the Chun''an soil (p<0.05), while it had a less pronounced effect in the Jiyuan soil. In the Jiyuan soil, the amendments with sulfuric acid-and hydrochloric acid-washed HBCR resulted in 20.9% and 33.1% decrease in the concentrations of DTPA-extractable Pb, respectively. In the Chun''an soil, the amendments with all three HBCRs decreased DTPA-extractable Pb concentrations for 26.8%~41.8%. When applied alone or with phosphate, the sulfuric acid-washed HBCR reduced DTPA-extractable Cu and Zn more than the hydrochloric acid-washed HBCR. The results suggest that the HBCR has better immobilization effect on heavy metals in acid soils than in calcareous soils, and the sulfuric acid-washed HBCR differs from hydrochloric acid washed-HBCR in the immobilization of heavy metals in soil.