生物炭对镉污染土壤环境质量的影响

The Effect of Biochar on the Environmental Quality of Cadmium-Contaminated Soil

摘要: 目的：探究生物炭对镉污染土壤环境质量的影响，为有效实施土壤镉污染治理与修复提供参考与借鉴。方法：本研究以花生壳生物炭为试验材料，通过盆栽控制试验研究3种不同镉水平下不同生物炭施用量对土壤养分含量和酶活性的影响。结果：不同试验处理土壤铵态氮、硝态氮、速效磷和可溶性有机碳的含量随时间延长呈下降趋势。与第28 d相比，第90 d时三种Cd水平下土壤可溶性有机碳含量分别下降了63.42%、64.54%和49.86%；速效磷含量分别降低了48.99%、61.1%和59.85%；随着生物炭添加量的增加，3种Cd水平下土壤有效养分含量呈增加的趋势，其中生物炭添加量最大的O(4)处理、L(4)处理和H(4)处理的增幅最大。生物炭施用对土壤酶活性的影响显著。3种Cd水平下，生物炭添加量较高时，土壤脲酶活性、过氧化氢酶活性和碱性磷酸酶活性均高于生物炭用量较低的处理。但当生物炭添加量达到4%后，土壤中三种酶的活性受到抑制，活性均低于未添加生物炭的土壤酶活性水平。结论：生物炭添加可以增加土壤中可溶性有机碳、速效磷、硝态氮和铵态氮的含量；一定的生物炭添加量有助于提高土壤酶活性，而过量的生物炭添加则会抑制土壤酶活性。

Abstract: Objective: To explore the effect of biochar on the environmental quality of cadmium-contaminated soil, providing a reference for effective implementation of soil cadmium pollution control and reme-diation. Method: This study used peanut shell biochar as the experimental material to study the ef-fects of different biochar application rates on soil nutrient content and enzyme activity under three different cadmium levels through a pot-controlled experiment. Results: The content of ammonium nitrogen, nitrate nitrogen, available phosphorus, and soluble organic carbon in soil under different experimental treatments showed a decreasing trend over time. Compared with the 28th day, the soil soluble organic carbon content decreased by 63.42%, 64.54%, and 49.86% at the three Cd lev-els on the 90th day, respectively; the content of available phosphorus decreased by 48.99%, 61.1%, and 59.85%, respectively; with the increase of biochar addition, the soil effective nutrient content showed an increasing trend at three Cd levels, among which the O(4) treatment with the highest biochar addition, the L(4) treatment, and the H(4) treatment showed the greatest increase. The ap-plication of biochar has a significant impact on soil enzyme activity. Under the three Cd levels, the soil urease activity, catalase activity, and alkaline phosphatase activity were higher when the amount of biochar added was higher than when the amount of biochar was lower. But when the amount of biochar added reaches 4%, the activity of the three enzymes in the soil is inhibited, and the activity is lower than the level of soil enzyme activity without biochar added. Conclusion: The addition of biochar can increase the content of soluble organic carbon, available phosphorus, nitrate nitrogen, and ammonium nitrogen in the soil; a certain amount of biochar addition helps to improve soil enzyme activity, while excessive biochar addition inhibits soil enzyme activity.