不同钝化材料对镉污染土壤修复效果研究

Study on the Remediation Effects of Different Passivation Materials on Cadmium-Contaminated Soils

摘要: 农田土壤镉(Cd)污染是制约耕地安全利用、威胁农产品质量安全的突出环境问题，原位钝化技术因成本低廉、操作简便、适配大田生产等优势，成为Cd污染农田修复的重要技术。为明确木本泥炭、微生物菌剂和石灰三种典型钝化材料对Cd污染农田的修复效果及应用差异，本研究设置对照组(CK)、木本泥炭钝化处理(NT)、微生物菌剂处理(WSW)和石灰钝化处理(SH) 4组田间试验，探究不同钝化材料对土壤理化性质和水稻生长的影响。结果表明：相较于CK，SH处理可显著提升土壤pH值，有效改善土壤酸化状况，土壤有效态Cd含量降幅最优；NT与WSW处理对土壤pH调控作用较弱，但均可有效降低土壤有效态Cd含量，二者钝化效果无显著差异；各钝化处理对水稻产量均无抑制作用，有利于维持农田稳定生产力；不同钝化材料对水稻籽粒Cd累积的影响存在明显差异，其中NT处理水稻籽粒Cd含量最低，对作物可食部位Cd富集的阻控效果最优，而WSW处理未表现出明显抑制Cd向水稻籽粒转运累积的作用。综上，石灰更适用于酸化Cd污染土壤的钝化修复，木本泥炭在农产品Cd安全管控方面优势显著，微生物菌剂单一修复效果有限，建议实际生产中采用复配施用模式。

Abstract: Cadmium (Cd) pollution in farmland soil is a major environmental challenge, endangering the safe use of agricultural land and food safety. In-situ passivation technology has become an important repair method because of its high cost efficiency, simple operation and suitability for large-scale field applications. To evaluate the remediation efficacy and application differences of three typical materials—woody peat, microbial inoculant, and lime—this study conducted four field experiments: a control group (CK), woody peat treatment (NT), microbial inoculants treatment (WSW), and lime treatment (SH). The study investigated their impacts on soil physicochemical properties and rice growth. Results demonstrated that the SH treatment significantly increased soil pH, effectively alleviating acidification, and achieved the most substantial reduction in available Cd content compared to CK. While NT and WSW treatments exhibited weaker pH-regulating effects, both effectively lowered available Cd levels, with no significant difference between them. None of the treatments inhibited rice yield, supporting stable agricultural productivity. The impact of different materials on Cd accumulation in rice grains varied markedly: NT treatment resulted in the lowest Cd levels in grains and the most effective control over Cd accumulation in edible parts, whereas WSW showed no significant inhibitory effect on Cd transport and accumulation. In conclusion, lime is most suitable for passivating acidic Cd-contaminated soils; Woody peat demonstrates distinct advantages in ensuring Cd safety in agricultural products; and microbial inoculant treatment has limited efficacy. A combined application strategy is recommended for practical implementation.