Zhao Bing, Xu Zhi, Li Shaoming, Yang Zhixin, Ling Wen, Wu Zhicheng, Gao Jiangfei, Wang Yuyun
College of Resources and Environmental Science, Yunnan Agricultural University, Kunming, 650201, Yunnan, China.
College of Resources and Environmental Science, Yunnan Agricultural University, Kunming, 650201, Yunnan, China; Organic Recycling Institute (Suzhou) of China Agricultural University, Suzhou, 215128, Jiangsu, China.
J Environ Manage. 2024 Aug;365:121599. doi: 10.1016/j.jenvman.2024.121599. Epub 2024 Jul 4.
To enhance the remediation effect of heavy metal pollution, organic fertilizers with different maturity levels were added to cadmium-contaminated soil. The remediation effect was determined by evaluating the form transformation and bioavailability of cadmium in heavy metal-contaminated soil. -Results showed that when the maturity was 50%, although the soil humus (HS) content increased, it didn't contribute to reducing the bioavailability of soil Cd. Appropriately increasing the maturity (GI ≥ 80%), the HS increased by 113.95%∼157.96%, and reduced significantly the bioavailability of soil Cd, among the exchangeable Cd decreased by 16.04%∼33.51% (P < 0.01). The structural equation modeling (SEM) revealed that HS content is a critical factor influencing the transformation of Cd forms and the reduction of exchangeable Cd accumulation; the HS and residual Cd content were positively correlated with the maturity (P < 0.01), while exchangeable Cd content was negatively correlated with maturity (P < 0.01), and the correlation increased with increasing maturity. In summary, appropriately increasing the maturity (GI ≥ 80%) can increase significantly HS, promote the transformation of exchangeable Cd into residual Cd, and ultimately enhance the effectiveness of organic fertilizers in the remediation of soil Cd pollution. These results provide a new insight into the remediation of Cd-contaminated soil through organic fertilizer as soil amendment in Cd-contaminated soil.
为提高重金属污染的修复效果，将不同成熟度水平的有机肥添加到镉污染土壤中。通过评估重金属污染土壤中镉的形态转化和生物有效性来确定修复效果。结果表明，当成熟度为50%时，虽然土壤腐殖质（HS）含量增加，但对降低土壤镉的生物有效性并无帮助。适当提高成熟度（GI≥80%），HS增加了113.95%～157.96%，并显著降低了土壤镉的生物有效性，其中可交换态镉下降了16.04%～33.51%（P<0.01）。结构方程模型（SEM）表明，HS含量是影响镉形态转化和可交换态镉积累减少的关键因素；HS和残留镉含量与成熟度呈正相关（P<0.01），而可交换态镉含量与成熟度呈负相关（P<0.01），且相关性随成熟度增加而增强。综上所述，适当提高成熟度（GI≥80%）可显著增加HS，促进可交换态镉向残留态镉的转化，最终提高有机肥对土壤镉污染的修复效果。这些结果为通过在镉污染土壤中添加有机肥来修复镉污染土壤提供了新的见解。
