摘要
通过田间试验,探究锰基改性稻壳生物炭对弱碱性Cd污染土壤有机碳含量、团聚体结构以及团聚体各粒级的Cd质量负载和有效态含量的影响.结果表明,施加改性生物炭,土壤有机碳含量表现为随着改性生物炭施加量的增加而呈现出逐渐升高的趋势,较对照增加了3.2%~32.0%.改性生物炭对土壤团聚体的分布结构和稳定性具有改良作用,增加了大团聚体(5~8 mm和2~5 mm粒级)所占的质量分数,微团聚体(≤0.25 mm)则受到抑制,土壤团聚体平均质量直径(GWD)、几何平均直径(MWD)和土壤团粒结构体(R0.25)较对照分别增加了15.1%~20.3%、 8.1%~22.4%和0.43%~7.6%.Cd含量主要富集在团聚体小颗粒中,其在土壤团聚体各粒级的质量负载随粒径的减小而逐渐增大.Cd分布因子在0.5~1 mm和0.25~0.5 mm粒级中表现出明显富集状况,而在5~8 mm和2~5 mm粒径中表现出明显亏损状态.与对照相比,添加改性生物炭降低了全土和土壤团聚体各粒级中DTPA-Cd含量,其中在5~8、 2~5、 0.5~1.0和0.25~0.5 mm粒径中分别降低了7.6%~15.1%、 15.6%~24.3%、 3.6%~13.8%和11.6%~13.7%(P<0.05).总体而言,改性生物炭不仅对污染土壤团聚体的结构具有良好的优化作用,而且能够降低不同粒径土壤中Cd有效态含量,达到阻控修复Cd污染的目的.
Field experiments were conducted to investigate the effects of Mn-based modified rice husk biochar on soil organic carbon,aggregate structure,mass load,and the content of available Cd in aggregates.The results showed that the concentration of soil organic carbon increased gradually with additional modified biochar,resulting in a 3.2%-32%increase compared with the CK.Modified biochar improved the composition structure and stability of soil aggregates,and increased the amount of large aggregates(5-8 mm and 2-5 mm),while micro-aggregate production was inhibited(≤0.25 mm).Compared with the CK,mean weight diameter(MWD),geometrical mean weight(GMD),and soil aggregate structural body(R0.25)of the soil aggregates increased by 15.1%-20.3%,8.1%-22.4%,and 0.43%-7.6%,respectively.Cd was preferentially enriched on small aggregates,and the mass loading of Cd in soil aggregates increased gradually with decreasing particle size.The distribution factor of Cd showed significant enrichment in the 0.5-1 mm and 0.25-0.5 mm grain sizes,whereas it showed a clear loss in particle sizes of 5-8 mm and 2-5 mm.The addition of modified biochar reduced the content of DTPA-Cd in soil aggregates,causing 7.6%-15.1%,15.6%-24.3%,3.6%-13.8%,and 11.6%-13.7%reductions in 5-8,2-5,0.5-1.0,and 0.25-0.5 mm particle sizes,respectively.In general,modified biochar not only has a favorable optimizing function on the structure of soil aggregates,but also decreases the content of available Cd in different sizes of soil aggregates,increasing its significance in the remediation of Cd-contaminated soil.
作者
孙彤
付宇童
李可
徐应明
孙约兵
SUN Tong;FU Yu-tong;LI Ke;XU Ying-ming;SUN Yue-bing(Key Laboratory of Original Agro-Environmental Pollution Prevention and Control,Ministry of Agriculture and Rural Affairs(MARA),Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety,Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,China;College of Resources and Environment,Northeast Agricultural University,Harbin 150030,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第7期3426-3433,共8页
Environmental Science
基金
国家重点研发计划项目(2018YFD0800300)
国家自然科学基金项目(31971525)
天津市自然科学基金重点项目(17JCZDJC34200)。
关键词
锰基改性生物炭
团聚体
CD污染
弱碱性土壤
钝化修复
Mn-modified biochar
soil aggregates
Cd pollution
weakly alkaline soil
immobilization remediation
