1
|
Cao J, Guo Z. Spatial patterns of toxic elements in stream sediment transportation at a hilly mine area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174597. [PMID: 38986691 DOI: 10.1016/j.scitotenv.2024.174597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 06/13/2024] [Accepted: 07/06/2024] [Indexed: 07/12/2024]
Abstract
The spatial pattern of toxic metals plays a major role in watershed diffuse metal non-point source pollution, particularly during stream sediment transportation at hills mines. This study investigated a typical hilly mine area to quantitatively analyze the characteristics, sensitivities, and influencing factors of toxic elements transported in stream sediments through field research and Geodetector models. The results showed that the spatial patterns of toxic elements in stream sediment transportation at the hills mine area were significantly influenced by water erosion and sulfate. Water erosion and sulfate promoted the transport differences of stream sediment metals from upstream to downstream at the hills mine area. Arsenic, cadmium, mercury, and antimony in the stream sediments at the hills mine exhibited higher coefficients of variation (101 % to 397 %) than those in plain and basin topographies. Potential ecological risks of arsenic and cadmium were assessed as high-risk levels, at 19 % and 64 %, respectively. Metal import in the midstream sediments of the hills mine area was accelerated by strong water erosion. Sulfate and dissolved organic matter (DOM) were highly enriched in stream sediments, with sulfate showing a strong correlation with toxic metals (24 %). Positive responses were observed between arsenic, mercury, antimony, and sulfate in sediments, with sensitivities of 41 %, 25 %, and 16 %, respectively, while cadmium was associated with DOM, with a sensitivity of 46 %. Importantly, water erosion interactions with functional type of mine significantly influenced on the spatial transportation patterns of toxic metals in stream sediments. The interactive influences of sulfate combined with bicarbonate on arsenic, mercury, and antimony and bicarbonate combined with DOM on cadmium were enhanced compared to individual factors (>20 %). This study elucidates the spatial patterns of metals during stream sediment transportation in hills mine and offers the novel insights for developing effective watershed metal management strategies in hilly mine environments.
Collapse
Affiliation(s)
- Jie Cao
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Zhaohui Guo
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| |
Collapse
|
2
|
Li X, Li Y, Yang S. Enhanced mineralization of nitrophenols by a novel C@ZVAl-PS based sequential reduction-oxidation process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 950:175288. [PMID: 39111419 DOI: 10.1016/j.scitotenv.2024.175288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/03/2024] [Accepted: 08/02/2024] [Indexed: 08/11/2024]
Abstract
Widely employed nitrophenols (NPs) are refractory and antioxidant due to their strong electron-withdrawing group (-NO2). Actually, NPs are readily reduced to aminophenols (APs). However, APs remain toxic and necessitate further treatment. Herein, we utilized a novel sequential reduction-oxidation system of carbon-modified zero-valent aluminum (C@ZVAl) combined with persulfate (PS) for the thorough removal of both NPs and APs. The results demonstrated that p-nitrophenol (PNP, up to 1000 mg/L) exhibited complete reduction to p-aminophenol (PAP), and then over 98.0 % of PAP could be effectively oxidized, in the meantime the removal rate of chemical oxygen demand (COD) was as high as 95.9 %. Based on the SEM and XPS characterizations, we found that C@ZVAl has exceptionally high reactivity that generates massive electrons and reduces PNP to PAP through accelerated electron transfer. In the subsequent oxidation step, PS can be rapidly activated by C@ZVAl to generate SO4- radicals for PAP oxidization. Meanwhile, the mineralization of COD proceeds. The temporal binding of reduction and oxidation can be regulated by varying the PS dosing time. Namely, the appropriate delay in PS dosing facilitates sufficient reduction to provide enough reactants for oxidation, favoring the mineralization of PNP and COD. More crucially, dinitrodiazophenol (DDNP) in an actual explosive wastewater without any pretreatment can be effectively mineralized by this sequential reduction-oxidation system, affirming the excellent performance of this process in practical applications. In conclusion, the C@ZVAl-PS based sequential reduction-oxidation looks very promising for enhanced mineralization of nitro-substituted organic contaminants.
Collapse
Affiliation(s)
- Xin Li
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Yang Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Shiying Yang
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China; Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering (MEGE), Qingdao 266100, China; College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
| |
Collapse
|
3
|
Zhang K, Jiang S, Zhang J, Zheng J, Li P, Wang S, Bi R, Gao L. Phycoremediation and valorization of hypersaline pickled mustard wastewater via Chaetoceros muelleri and indigenous bacteria. BIORESOURCE TECHNOLOGY 2024; 393:130172. [PMID: 38086464 DOI: 10.1016/j.biortech.2023.130172] [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: 10/08/2023] [Revised: 11/14/2023] [Accepted: 12/06/2023] [Indexed: 01/18/2024]
Abstract
Hypersaline pickled mustard wastewater (PMW), a typical food wastewater with high nutrient content, was successfully bioremediated via the co-treatment of Chaetoceros muelleri and indigenous bacteria in this study. Chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus in 10 % PMW could be effectively reduced by 82 %, 90 %, 94 % and 96 %, respectively, after 12 days treatment. Oxygen species activities, malondialdehyde content, microalgal biomass, photosynthesis and extracellular polymeric substances were characterized during the treatment to determine the responses of the consortium when exposed to different concentration of PMW. Microbial community analysis demonstrated a significant increase in the relative abundance of Halomonas and Marinobacter in the 10 % PMW after 12 days treatment, which was beneficial for nutrients recycling by the diatoms. Meanwhile, C. muelleri was effective in reducing the relative abundance of potentially pathogenic bacteria Malaciobacter. In conclusion, the work here offers a promising and environmentally friendly approach for hypersaline wastewater treatment.
Collapse
Affiliation(s)
- Kai Zhang
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China; College of Environment and Ecology, Chongqing University, Chongqing 400044, PR China
| | - Shuqin Jiang
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China
| | - Juan Zhang
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China
| | - Jishu Zheng
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China
| | - Ping Li
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China
| | - Song Wang
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518061, PR China.
| | - Ru Bi
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China
| | - Lihong Gao
- Research Institute of Agricultural Engineering, Chongqing Academy of Agricultural Sciences, Chongqing 401329, PR China; Chongqing Key Laboratory of Agricultural Waste Resource Utilization Technology and Equipment Research, Chongqing 401329, PR China.
| |
Collapse
|