生物炭对重金属污染土壤养分的影响及修复效果研究

The Nutrient and Remediation Effect of Biochar on Heavy Metal Contaminated Soil

摘要: 通过生物炭–小白菜盆栽试验，研究果木炭与猪粪炭在0%，5%和10% (以风干土计)添加量下种植小白菜后对重金属污染土壤养分及修复效果的影响。结果表明：种植小白菜前后猪粪炭的添加有利于土壤pH、全氮、有效磷和速效钾的含量的提升与保持。种植前相较CK组，pH、全氮和速效钾含量随两种生物炭浓度增加而增加，有效磷含量随浓度增加而略有下降。种植后，两种生物炭的添加均减缓了土壤中养分含量的下降。生物炭–小白菜联合修复不利于供试土壤中总Cr、总Ni、总Cu和总As的修复，而对总Pb、总Hg、总Zn和总Cd的修复有利，修复效果依次为总Pb > 总Hg > 总Zn > 总Cd。其中猪粪炭对总Pb、总Zn和总Cd的修复更有利，果木炭对总Hg的修复更有利，且随浓度增加效果更显著。后期复合重金属污染土壤修复实践中，可优先选用猪粪炭，且10%的用量效果较佳。

Abstract: Through the biochar-cabbage pot experiment, the effects of fruit biochar and swine biochar on the nutrient and remediation effect of heavy metal contaminated soil before and after planting cabbage at the concentration of 0%, 5% and 10% (in terms of dry soil) were studied. The results showed that the addition of swine biochar before and after planting cabbage was beneficial to the improvement and maintenance of soil pH, total nitrogen, available phosphorus and available potassium. Compared with CK group before planting, the pH, total nitrogen and available potassium of the soil increased with the increase of two biochar concentrations, and the available phosphorus content decreased slightly with the increasing concentration. After planting, the addition of both biochars slowed down the decline of the nutrient content of the soil. In this test, the biochar-cabbage was not conducive to the repair of total Cr, Ni, Cu and As, but was beneficial to the restoration of total Pb, Hg, Zn and Cd. The repair effect was total Pb > total Hg > total Zn > total Cd. Among them, swine biochar was more beneficial to the repair of total Pb, total Zn and total Cd. The fruit biochar was more favorable for the repair of total Hg, and the remediation effect was more significant with the increase of concentration. In the later practice of compound heavy metal contaminated soil remediation, swine biochar can be preferred, and the concentration of 10% was better.