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Luo Y, He Y, Zhou D, Pan L, Wu Y. Organic amendment application affects the release behaviour, bioavailability, and speciation of heavy metals in zinc smelting slag: Insight into dissolved organic matter. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133105. [PMID: 38056253 DOI: 10.1016/j.jhazmat.2023.133105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/12/2023] [Accepted: 11/26/2023] [Indexed: 12/08/2023]
Abstract
Organic amendments are commonly used in assisted phytostabilization of mine wastes by improving their physicochemical and biological properties. These amendments are susceptible to leaching and degradation, resulting in the generation of dissolved organic matter (DOM), which significantly influences the geochemical behaviour of heavy metals (HMs). However, the geochemical behaviour of HMs in metal smelting slag driven by organic amendment-derived DOM remains unclear. In this study, we investigated the impact of cow manure-derived DOM on the release behaviour, bioavailability, and speciation of HMs (Cu, Pb, Zn, and Cd) in zinc smelting slag using a multidisciplinary approach. The results showed that DOM enhanced the weathering of the slag, with a minimal impact on the slag's mineral phases, except for causing gypsum dissolution. The DOM addition resulted in a slight increase in HM release from the slag during the initial inoculation period, followed by a reduction in HM release during the later period. Furthermore, the DOM addition increased the diversity and relative abundance of the bacterial community. This, in turn, led to a decrease in the dissolved organic carbon (DOC) content and enhanced the transformation of labile DOM compounds into recalcitrant compounds. The variation in HM release during various inoculation periods can be attributed to the bacterial decomposition and transformation of DOM, which further enhanced the transformation of HM fractions. Specifically, during the later period, DOM promoted the conversion of a portion of the reducible and oxidizable fractions of Cu, Pb, and Zn into the acid-soluble and residual fractions. Moreover, it partially transformed the reducible, oxidizable, and residual fractions of Cd into the acid-soluble fraction. Overall, this study provides new insights into the geochemical behaviour of HMs in slag governed by the coupling effect of DOM and the bacterial community. These findings have implications for the use of organic amendments in assisted phytostabilization of metal smelting slag. ENVIRONMENTAL IMPLICATION: Metal smelting slag is hazardous due to its high levels of HMs, and its improper disposal has serious consequences for the ecosystem. Organic amendments are employed in assisted phytostabilization of the slag site by improving its microecological properties. However, the impact of organic amendment-derived DOM on HM migration and transformation in slag remains unclear. This study indicated that the coupling effects of DOM and microbes governed the geochemical behaviour of HMs in slag. These findings provide new insights into how organic amendments impact the geochemical behaviour of HMs in slag, contributing to the development of phytostabilization technology.
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Affiliation(s)
- Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou, University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China.
| | - Yu He
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Dongran Zhou
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Lishan Pan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yonggui Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou, University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China
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Zhang S, Li T, Hu J, Li K, Liu D, Li H, Wang F, Chen D, Zhang Z, Fan Q, Cui X, Che R. Reforestation substantially changed the soil antibiotic resistome and its relationships with metal resistance genes, mobile genetic elements, and pathogens. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118037. [PMID: 37178462 DOI: 10.1016/j.jenvman.2023.118037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/13/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023]
Abstract
Revealing the effects of reforestation on soil antibiotic resistome is essential for assessing ecosystem health, yet related studies remain scarce. Here, to determine the responses of the soil antibiotic resistome to reforestation, 30 pairs of cropland and forest soil samples were collected from southwestern China, a region with high environmental heterogeneity. All the forests had been derived from croplands more than one decade ago. The diversity and abundance of soil antibiotic resistance genes (ARGs), metal resistance genes (MRGs), mobile genetic elements (MGEs), and pathogens were determined by metagenomic sequencing and real-time PCR. The results showed that reforestation significantly increased soil microbial abundance and the contents of Cu, total carbon, total nitrogen, total organic carbon, and ammonium nitrogen. Nevertheless, it decreased the contents of soil Zn, Ba, nitrate nitrogen, and available phosphorus. The main soil ARGs identified in this region were vancomycin, multidrug, and bacitracin resistance genes. Reforestation significantly increased the soil ARG abundance by 62.58%, while it decreased the ARG richness by 16.50%. Reforestation exerted no significant effects on the abundance of heavy metal resistance genes and pathogens, but it doubled the abundance of MGEs. Additionally, reforestation substantially decreased the co-occurrence frequencies of ARGs with MRGs and pathogens. In contrast, the correlation between ARGs and MGEs was greatly enhanced by reforestation. Similarly, the correlations between soil ARG abundance and environmental factors were also strengthened by reforestation. These findings suggest that reforestation can substantially affect the soil antibiotic resistome and exerts overall positive effects on soil health by decreasing ARG richness, providing critical information for assessing the effects of "grain for green" project on soil health.
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Affiliation(s)
- Song Zhang
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China; State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Ting Li
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China; College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinming Hu
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China
| | - Kexin Li
- Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China
| | - Dong Liu
- School of Life Sciences, Yunnan University, Kunming, 650091, China
| | - Haixia Li
- Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Fang Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Danhong Chen
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China
| | - Zejin Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiuping Fan
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China
| | - Xiaoyong Cui
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rongxiao Che
- Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security, Yunnan University, Kunming, 650500, China.
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