| 引用本文: | 王志刚，王永杰，靳雯佳，孙亚飞，任少芳，周立旻，郑祥民.2021.两种生物炭对稻米中砷累积的影响研究[J].地球环境学报,12(3):313-321 |
| WANG Zhigang, WANG Yongjie, JIN Wenjia, SUN Yafei, REN Shaofang, ZHOU Limin, ZHENG Xiangmin.2021.The influence of two different biochar treatments on arsenic accumulation in rice plants[J].Journal of Earth Environment,12(3):313-321 |
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| 摘要: |
| 为探究土壤添加低剂量生物炭对稻米中砷累积的影响及作用机理，使用矿区砷污染土壤添加小麦和棉花秸秆生物炭进行盆栽和模拟试验。盆栽试验结果表明：添加质量分数为0.5%的低剂量小麦和棉花秸秆生物炭，可以降低稻米（糙米）砷浓度（约10%），作用有限。糙米中砷浓度的降低主要是由于其生物量增加所致。模拟试验结果表明：添加质量分数为1%—5%的高剂量生物炭可以显著促进土壤中砷释放，相比对照组，生物炭添加组土壤溶液中砷浓度增加了69%—243%，推测其可能是生物炭促进了微生物作用下铁氧化物的还原，进而导致砷释放。研究表明：土壤中施加低剂量小麦和棉花秸秆生物炭对减少水稻砷累积作用可能有限，而高剂量可能增加水稻砷污染健康风险。 |
| 关键词: 生物炭 砷 土壤 水稻 |
| DOI：10.7515/JEE202022 |
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| 基金项目:国家自然科学基金项目（41771508，41871015） |
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| The influence of two different biochar treatments on arsenic accumulation in rice plants |
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WANG Zhigang, WANG Yongjie, JIN Wenjia, SUN Yafei, REN Shaofang, ZHOU Limin, ZHENG Xiangmin
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1. Key Laboratory of Geographic Information Science, Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai 200241, China
2. Institute of Eco-Chongming, East China Normal University, Shanghai 200241, China
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| Abstract: |
| Background, aim, and scope The accumulation of arsenic (As) in rice grown in As-contaminated soils and the negative impacts on human health are among the most important food security concerns globally. However, green and economically feasible remediation measures for mitigating the health risks of dietary As exposure from rice consumption have scarcely been reported. To determine the effects of wheat and cotton straw-derived biochar on As accumulation in rice plants and As mobility in soil under anoxic conditions, pot and microcosm experiments were conducted by using As-contaminated soil. Materials and methods Two different biochars derived from wheat and cotton straw were produced at 600℃ (1 h) and added to As-contaminated soil under different doses. The variety of rice Yongyou 538 was cultivated in pot experiments. We determined As concentrations in different rice tissues (including brown rice, rice straw and roots), porewater and soil during the rice growth period. In addition, a 28-day microcosm experiment was conducted following additions of different biochar doses (0.5%—5.0%, mass fraction) under anaerobic conditions. The total concentrations of As in all samples were determined by an atomic fluorescence spectrometer (AFS—9230, Jitian, Beijing, China) with a detection limit of 0.02 μg·L−1. Results The results of the pot experiments showed that: (1) the addition of low dose biochar (0.5%) reduced the As concentrations by approximately 10% in grains (brown rice), indicating a limited effect of biochar addition on reducing As accumulation in rice grains. Results of the microcosm experiments showed that the addition of high doses of biochar (1%—5%) significantly promoted the release of As into the soil solution. Compared with the control groups, the total dissolved As in soil solutions of biochar-added treatments increased by 69%—243%. Discussion The decrease in As concentrations in brown rice may be attributed largely to increased grain biomass following biochar addition. The significant increases in dissolved As in soil solution may be linked to microbial iron(Ⅲ) oxide-hydroxide reduction, resulting in the release of As into the soil water. Conclusions These results suggest that low-dose biochar addition may not be an effective way to reduce the accumulation of As in rice. Moreover, high-dose biochar addition may actually increase the As-related health risk in As-contaminated paddy soils. Recommendations and perspectives Biochars pyrolyzed by different feedstocks may have different effects on As accumulation in rice. Thus, more research is required to further assess and develop biochars as a high-efficiency material for As remediation in soil. |
| Key words: biochar arsenic soil rice |
