Synergistic effect between biochar and nitrate fertilizer facilitated arsenic immobilization in an anaerobic contaminated paddy soil

被引：0

作者：

Jia, Wenli ^{[1
]}

Yu, Zhi ^{[2
]}

Chen, Junfeng ^{[3
]}

Zhang, Jian ^{[1
,4
,5
]}

Zhu, Jian ^{[5
]}

Yang, Wentao ^{[5
]}

Yang, Ruidong ^{[5
]}

Wu, Pan ^{[1
]}

Wang, Shengsen ^{[6
]}

机构：

[1] Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang,550025, China

[2] Guizhou Research and Designing Institute of Environmental Sciences, Guiyang,550081, China

[3] Geological Brigade 105, Bureau of Geology and Mineral Exploration and Development of Guizhou Province, Guiyang,550018, China

[4] Guizhou Karst Environmental Ecosystem Observation and Research Station, Ministry of Education, Guiyang,550025, China

[5] College of Resources and Environmental Engineering, Guizhou University, Guiyang,550025, China

[6] College of Environmental Science and Engineering, Yangzhou University, Yangzhou,225127, China

来源：

Science of the Total Environment | 2024年 / 955卷

关键词：

Soil pollution;

D O I：

10.1016/j.scitotenv.2024.177007

中图分类号：

学科分类号：

摘要：

Nitrate nitrogen fertilizer was usually used to mitigate arsenic (As) release and mobilization in the anaerobic contaminated paddy soil. However, the effect of the interplay between nitrate fertilizer and biochar on As availability as well as the involved mechanism were poorly understood. Herein, the effects and mechanisms of biochar, nitrate fertilizer, and biochar-based nitrate fertilizer on the availability of As in the contaminated paddy soil were investigated via a microcosm incubation experiment. Results indicated that the application of biochar-based nitrate fertilizer significantly lessened the available As concentration in the contaminated paddy soil from 3.01 ± 0.03 (control group) to 2.24 ± 0.08 mg kg−1, which presented an immobilization efficiency of 26.6 % better than those of individual biochar (13.5 %) and nitrate fertilizer (17.6 %), exhibiting a synergistic effect. Moreover, the biochar-based nitrate fertilizer also facilitated the transformation of more toxic arsenite in the contaminated soil to less toxic arsenate. Further, biochar-based nitrate fertilizer increased soil redox potential (Eh), dissolved organic carbon, organic matter, and nitrate yet decreased soil pH and ammonium, which changed the microbial community in the soil, enhancing the relative abundance of Bacillus, Arthrobacter, and Paenibacillus. These functional microorganisms drove the coupled transformation between nitrate denitrification and Fe(II) or As(III) oxidation, favoring As immobilization in the anaerobic paddy soil. Additionally, the co-application of biochar offset the negative effect of single nitrate fertilizer on microbial community diversity. Overall, biochar-based nitrate fertilizer could be a promising candidate for the effective immobilization of As in the anaerobic paddy soil. The current research can provide a valuable reference to the remediation of As-contaminated paddy soil and the production of safe rice. © 2024

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