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Zhu F, Guo X, Gao H, Shi Y, Wang G, Du C, Jiang J, Wu Y, Hartley W, Xue S. Ecological restoration affects the dynamic response of alkaline minerals dissolution in bauxite residue. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169364. [PMID: 38104818 DOI: 10.1016/j.scitotenv.2023.169364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 11/19/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Regulating alkalinity is the key process to eliminating environmental risk and implementing sustainable management of bauxite residue. Nevertheless, continuous release of free alkali from the solid phase (mainly sodalite and cancrinite) is a major challenge for long-term stability of alkalinity in amended bauxite residue. In order to understand the dissolution behavior of sodalite and cancrinite, their dissolution kinetics under simulated pH conditions of 8, 9 and 10 were investigated. Additionally, PHREEQC software and shrinking core model (SCM) were employed to analyze the release pattern of saline ions. The results revealed that the ratio of Na/Si and Na/Al values exhibited greater stability in sodalite than in cancrinite. The dissolution of elemental Na, Si, and Al in sodalite and cancrinite was matched with non-chemometric characteristics. The kinetic calculations by the shrinking core model (SCM) suggested that both sodalite and cancrinite exhibited slow dissolution kinetics, and their dissolution processes belong to internal diffusion control and external diffusion control, respectively. pH controlled the dissolution kinetic rates of sodalite and cancrinite mainly by changing their coupled dissolution-precipitation processes. More importantly, these findings can predict the change of alkaline components accurately, thus facilitating the implementation of efficient alkalinity regulation strategies for the ecological restoration of bauxite residue disposal areas.
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Affiliation(s)
- Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Xuyao Guo
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Hui Gao
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | - Yafei Shi
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | | | - Chenxia Du
- Chinalco Mining Co, Ltd, Zhengzhou 450041, China
| | - Jun Jiang
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| | - Yujun Wu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China; College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - William Hartley
- Royal Agricultural University, Gloucestershire, United Kingdom
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
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Zhang Y, Gao H, Zhao D, Chen X, Zhu F, Li Y, Xue S. Microbially-driven alkaline regulation: Organic acid secretion behavior of Penicillium oxalicum and charge neutralization in bauxite residue. ENVIRONMENTAL RESEARCH 2024; 240:117489. [PMID: 37890830 DOI: 10.1016/j.envres.2023.117489] [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: 08/27/2023] [Revised: 10/21/2023] [Accepted: 10/23/2023] [Indexed: 10/29/2023]
Abstract
Microbially-driven alkaline neutralization in bauxite residue by functional microorganisms is a promising approach for the ecological rehabilitation on alkaline disposal areas. However, the alkali resistance and acid secretion mechanism of functional microorganisms are still unknown, which limits their application. Here, saline-alkaline resistance, acid production performance, and differentially expressed genes of Penicillium oxalicum (P. oxalicum, a functional fungus screened from a typical disposal area) were investigated and its bio-neutralization efficiency was evaluated. This fungus exhibited high tolerance to alkalinity (pH 12), and salinity (NaCl 2.0 M), and produced a large amount of oxalic acid to reduce the medium pH to 2.0. Transcriptome showed that alkali stress induced the overexpression of genes related to antioxidant and stress-resistant enzymes (GST, KatE) and glycolytic pathway rate-limiting enzymes (HK). The rate of glycolysis and other organic acid metabolism processes was increased with higher stress resistance of P. oxalicum. The integrated application of P. oxalicum and maize straw accelerated the dissolved organic carbon content and stabilized the leachate pH of bauxite residue at about 7.4. 3DEEM and BIOSEM analysis indicated that P. oxalicum maintained high activity in the residue leachate and continuously decomposed the maize straw for their metabolism. P. oxalicum showed strong alkaline resistance, biomass degradation capacity, and alkaline regulation potential, which should be beneficial for microbial-driven alkaline regulation in bauxite residue.
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Affiliation(s)
- Yifan Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| | - Hui Gao
- China Aluminum Mining Limited Company, Zhengzhou City, Henan Province 450041, China.
| | - Dongliang Zhao
- China Aluminum Mining Limited Company, Zhengzhou City, Henan Province 450041, China.
| | - Xueming Chen
- College of Environment and Safety Engineering, Fuzhou University, Fuzhou 350108, China.
| | - Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| | - Yinsheng Li
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
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Zhu F, Zhang X, Guo X, Yang X, Xue S. Root architectures differentiate the composition of organic carbon in bauxite residue during natural vegetation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 883:163588. [PMID: 37105477 DOI: 10.1016/j.scitotenv.2023.163588] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 04/13/2023] [Accepted: 04/15/2023] [Indexed: 06/03/2023]
Abstract
Understanding plant root architectures induced changes in organic carbon accumulation and conversion is critical to predicting carbon cycling and screening appropriate plant species for ecological restoration on bauxite residue disposal areas. According to the ecological investigation of a weathered bauxite residue disposal area, three plants with different root architectures including Artemisia lavandulaefolia (A. lavandulaefolia), moss, and Zanthoxylum simulans (Z. simulans) were selected to investigate the rhizosphere effects on the composition and structure of organic carbon in bauxite residue. The physic-chemical properties, the contents and structure of different organic carbon fractions, and microbial communities of bauxite residue from rhizosphere and non-rhizosphere were analyzed. Plant growth decreased the saline-alkalinity, increased the contents of total organic carbon, particulate organic carbon and dissolved organic carbon, whilst enhancing the enzymatic activities of bauxite residue. Meanwhile, the rhizosphere effects had significant effects on the accumulation and stabilization of organic carbon in bauxite residue. A. lavandulaefolia had the strongest rhizosphere effects on the composition and structure of total organic carbon and dissolved organic carbon, whilst moss was more effective on the accumulation of particulate organic carbon in bauxite residue. Plant growth and root architecture changed the abundance of specific functional microorganisms and the complexity of microbial co-occurrence networks, thus elevating organic carbon levels in bauxite residue. During natural vegetation encroachment, rhizosphere exciting effects of the salt-tolerated plants could change the composition and structure of organic carbon fractions due to the comprehensive effectiveness of the improvement of physic-chemical properties and microbial communities. The findings improve our understanding of the responses of sequestration and stabilization of organic carbon pools to ecological restoration on bauxite residue disposal areas.
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Affiliation(s)
- Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China; Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, PR China
| | - Xianchao Zhang
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Xuyao Guo
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Xingwang Yang
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China; Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, PR China.
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Wu Y, Deng D, Jiang J, Li F, Zeng J, Guo X, Zhu F, Jiang Y, Xue S. Ca-driven stable regulatory of alkalinity within desilication products: Experimental, modeling, transformation mechanism and DFT study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161708. [PMID: 36682559 DOI: 10.1016/j.scitotenv.2023.161708] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/14/2023] [Accepted: 01/15/2023] [Indexed: 06/17/2023]
Abstract
The prevalent pH rebound phenomenon in the bauxite residue alkalinity regulation is primarily caused by the presence of alkaline minerals, including sodalite and cancrinite. Calcium ion is widely used to remove the free alkali for reducing the alkalinity of bauxite residue, but its underlying mechanism on alkaline minerals is still unclear. In this work, we investigated the action mechanism of calcium ion on sodalite and cancrinite by various microspectroscopic methods, and then employed spin-polarized density functional theory (DFT) calculations to reveal the reaction pathways of calcium ion substitution and migration in minerals. The calcium ion can effectively regulate the stability of alkaline minerals by inhibiting alkaline ions release, which respectively enters sodalite and cancrinite by displacing Na adsorbed inside the mineral lattice and on the mineral surface. The entered calcium ion acts as competitive protection against sodium during the neutralization process, thus inhibiting the proton-promoted dissolution of sodalite and cancrinite. Moreover, the amount of entry calcium ion controls their acid neutralization ability. DFT calculations revealed calcium ions readily replaced sodium on the internal channels of minerals rather than on the surface. These new findings contribute to the understanding of potential options to directly stabilize critical alkaline components in bauxite residue.
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Affiliation(s)
- Yujun Wu
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China; College of Environment and Resources, Xiangtan University, Xiangtan 411105, PR China
| | - Dandan Deng
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Jun Jiang
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Feng Li
- College of Environment and Resources, Xiangtan University, Xiangtan 411105, PR China
| | - Jiaqing Zeng
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China.
| | - Xuyao Guo
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Yifan Jiang
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, PR China.
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Chao X, Zhang TA, Lyu G, Chen Y, Zhao Q, Yang X, Cheng F. Research on the mechanism of sodium separation in bauxite residue synergy preparation of potassium-containing compound fertilizer raw materials by the hydrothermal method. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 317:115359. [PMID: 35623128 DOI: 10.1016/j.jenvman.2022.115359] [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: 02/28/2022] [Revised: 05/04/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Bauxite residue poses an increasingly serious ecological safety problem in the alumina industry. A novel process for removing sodium in bauxite residue synergistic preparation of potassium-containing compound fertilizer raw materials was proposed to relieve pressure on the fertilizer industry. In this paper, synthetic sodalite and katoite were used to simulate the main mineral phases of bauxite residue to determine the suitable conditions for the method, and the transformation mechanism of the process was researched by analyzing the phase structure and microscopic morphology of the samples using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and specific surface area detection. The results show that the ideal reaction condition is 320 g/L K2O with solid reactants at 200 °C for 1 h. The separation rate of Na in the sodalite-katoite mixture reached 93.60%, with potassium aluminum silicate and katoite being the primary phases of the product, with a mesoporous structure and easy to be absorbed by crops. The bauxite residue transformation residue consisted of katoite and kaliophilite. With a total effective K2O, CaO, and SiO2 content of 38.22%, the Na2O content was 0.54%, meeting the requirements of compound fertilizer content on the market. The transformation mechanism is a dissolution-precipitation controlled sodium-potassium ion replacement reaction. This study provides theoretical guidance for the preparation of mineral fertilizer from bauxite residue and has practical production potential, opening up a new perspective for bauxite residue resource usage in the agricultural field.
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Affiliation(s)
- Xi Chao
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Ting-An Zhang
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China.
| | - Guozhi Lyu
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Yang Chen
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Qiuyue Zhao
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Xuewei Yang
- Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Special Metallurgy and Process Engineering Institute, School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Fangqin Cheng
- State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste Resources, Institute of Resources and Environmental Engineering, Shanxi University, Taiyuan, 030006, China
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