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Gao P, Wang J, Cui J, Yuan Y, Song Y. Experimental Study on the Effects of Carbonated Steel Slag Fine Aggregate on the Expansion Rate, Mechanical Properties and Carbonation Depth of Mortar. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3279. [PMID: 38998361 PMCID: PMC11243214 DOI: 10.3390/ma17133279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024]
Abstract
Steel slag is the main by-product of the steel industry and can be used to produce steel slag fine aggregate (SSFA). SSFA can be used as a fine aggregate in mortar or concrete. However, SSFA contains f-CaO, which is the main reason for the expansion damage of mortar and concrete. In this study, the carbonation treatment of SSFA was adopted to reduce the f-CaO content; the influence of the carbonation time on the content of f-CaO in the SSFA was studied; and the effects of the carbonated SSFA replacement ratio on the expansion rate, mechanical properties and carbonation depth of mortar were investigated through tests. The results showed that as the carbonation time increased, the content of f-CaO in the SSFA gradually decreased. Compared to the mortar specimens with carbonated SSFA, the specimens with uncarbonated SSFA showed faster and more severe damage and a higher expansion rate. When the replacement ratio of carbonated SSFA was less than 45%, the carbonated SSFA had an inhibitory effect on the expansion development of the specimens. The compressive strengths of the specimens with a carbonated SSFA replacement ratio of 60% and 45% were 1.29% and 6.81% higher than those of the specimens with an uncarbonated SSFA replacement ratio of 60% and 45%, respectively. Carbonation treatment could improve the replacement ratio of SSFA while ensuring the compressive strength of specimens. Compared with mortar specimens with uncarbonated SSFA, the anti-carbonation performance of mortar specimens with carbonated SSFA was reduced.
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Affiliation(s)
- Pengfei Gao
- Inspection and Certification Co., Ltd. MCC, Beijing 100088, China
| | - Jian Wang
- School of Civil Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Jianjun Cui
- Taishan Nuclear Power Joint Venture Co., Ltd., Taishan 529200, China
| | - Yongyu Yuan
- School of Civil Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yuanyuan Song
- School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China
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2
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Sahu JN, Kapelyushin Y, Mishra DP, Ghosh P, Sahoo BK, Trofimov E, Meikap BC. Utilization of ferrous slags as coagulants, filters, adsorbents, neutralizers/stabilizers, catalysts, additives, and bed materials for water and wastewater treatment: A review. CHEMOSPHERE 2023; 325:138201. [PMID: 36863629 DOI: 10.1016/j.chemosphere.2023.138201] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/05/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Solid waste is currently produced in substantial amounts by industrial activities. While some are recycled, the majority of them are dumped in landfills. Iron and steel production leaves behind ferrous slag, which must be created organically, managed wisely and scientifically if the sector is to remain more sustainably maintained. Ferrous slag is the term for the solid waste that is produced when raw iron is smelted in ironworks and during the production of steel. Both its specific surface area and porosity are relatively high. Since these industrial waste materials are so easily accessible and offer such serious disposal challenges, the idea of their reuse in water and wastewater treatment systems is an appealing alternative. There are many components such as Fe, Na, Ca, Mg, and silicon found in ferrous slags, which make it an ideal substance for wastewater treatment. This research investigates the potential of ferrous slag as coagulants, filters, adsorbents, neutralizers/stabilizers, supplementary filler material in soil aquifers, and engineered wetland bed media to remove contaminants from water and wastewater. Ferrous slag may provide a substantial environmental risk before or after reuse, so leaching and eco-toxicological investigations are necessary. Some study revealed that the amount of heavy metal ions leached from ferrous slag conforms to industrial norms and is exceedingly safe, hence it may be employed as a new type of inexpensive material to remove contaminants from wastewater. The practical relevance and significance of these aspects are attempted to be analyzed, taking into account all recent advancements in the fields, in order to help in the development of informed decisions about future directions for research and development related to the utilization of ferrous slags for wastewater treatment.
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Affiliation(s)
- J N Sahu
- University of Stuttgart, Institute of Chemical Technology, Faculty of Chemistry, D-70550 Stuttgart, Germany; South Ural State University (National Research University), Chelyabinsk, 454080, Russian Federation.
| | - Y Kapelyushin
- South Ural State University (National Research University), Chelyabinsk, 454080, Russian Federation
| | - Devi Prasad Mishra
- Department of Mining Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826 004, Jharkhand, India
| | - Prabir Ghosh
- Department of Chemical Engineering, NIT Raipur, Raipur, Chhattisgarh, India
| | - B K Sahoo
- Research & Development Centre for Iron & Steel, SAIL, Ranchi, Jharkhand, Pin-834002, India
| | - E Trofimov
- South Ural State University (National Research University), Chelyabinsk, 454080, Russian Federation
| | - B C Meikap
- Department of Chemical Engineering, Indian Institute of Technology (IIT), Kharagpur, West Bengal, 721302, India
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3
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Recycled Smelter Slags for In Situ and Ex Situ Water and Wastewater Treatment—Current Knowledge and Opportunities. Processes (Basel) 2023. [DOI: 10.3390/pr11030783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Slags from the ferrous and nonferrous metallurgical industries have been used to treat toxic contaminants in water and wastewater. Using slag as a recycling or renewable resource rather than a waste product has environmental and economic benefits. Recycled smelter slags can be used in both in situ and ex situ treatment. However, their application has some limitations. One of the challenges is how to handle spent slag adsorbents, as they contain the accumulation of solid waste loaded with high concentrations of toxic contaminants. These challenges can be overcome by regeneration, recycling, reuse, and immobilization treatment of spent slag adsorbents. The present paper explored the scientific and technical information about the composition, reaction mechanisms, adsorption capacity, and opportunities of recycled slags while adsorbing toxic compounds from contaminated water. It comprehensively reviewed the current state of the art for using smelting slags as sustainable adsorbents for water and wastewater. The study revealed that ferrous slags are more effective in removing a wide range of toxic chemicals than nonferrous smelter slags. It investigated the necessary improved approach through the 5Rs (i.e., reduce, reuse, recycle, remove, and recover) using smelter slags as reactive materials in ex situ and in situ treatment.
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4
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Sun L, Wu J, Wang J, Yang Y, Xu M, Liu J, Yang C, Cai Y, He H, Du Y, Hu P, Li Y, Li H. In-situ constructing nanostructured magnesium ferrite on steel slag for Cr(VI) photoreduction. JOURNAL OF HAZARDOUS MATERIALS 2022; 422:126951. [PMID: 34449339 DOI: 10.1016/j.jhazmat.2021.126951] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 08/10/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
An innovative method is created for transforming iron-rich RO phase (MgO0.239FeO0.761) on steel slag surface into nanostructured Mg0.04Fe2.96O4 layer. The phase change process is investigated, and it is found that salicylic acid modification and alkaline roasting procedures remarkably increase the specific surface area from 0.46 m2/g (raw steel slag) to 69.5 m2/g (Mg0.04Fe2.96O4), and the generation of Mg0.04Fe2.96O4 enhances the absorption of visible light and Cr(VI) conversion with 2-times increasement than raw steel slag. Surface complexation between H2C2O4 ligands and Fe metal moiety on Mg0.04Fe2.96O4 induces the intramolecular electron transfer under visible light irradiation based on a ligand-to-metal charge transfer mechanism, thus resulting in Cr(VI) photoreduction, and the catalytic efficiency is above 90% for Cr(VI) (40 mg/L) under inherent pH= 5.5 conditions. Moreover, recyclability tests based on magnetic separation show that the photoreactivity is closely related to Mg content of Mg0.04Fe2.96O4 layer where Mg leaching occurs and finally generates cubic spinel configuration Fe3O4. This work highlights the importance of surface functionalization in post-use phases of steel slag in which surface reactivity and application potential can be greatly altered by chemical exposure history and surface transformations. It also provides valuable references for studying the metastable state mechanism of magnesium ferrite photocatalysts.
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Affiliation(s)
- Lingmin Sun
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Junshu Wu
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China.
| | - Jinshu Wang
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China.
| | - Yilong Yang
- Henan Key Laboratory of Water Pollution Control and Rehabilitation Technology, Henan University of Urban Construction, Pingdingshan 467036, China
| | - Meng Xu
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Jingchao Liu
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Chen Yang
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Yongfeng Cai
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Heng He
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Yucheng Du
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Peng Hu
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Yongli Li
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
| | - Hongyi Li
- Key Laboratory of Advanced Functional Materials, Ministry of Education, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100022, China
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Huang Y, Liu H, Liu S, Li C, Yuan S. Glucose oxidase modified Fenton reactions for in-situ ROS generation and potential application in groundwater remediation. CHEMOSPHERE 2020; 253:126648. [PMID: 32298911 DOI: 10.1016/j.chemosphere.2020.126648] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/26/2020] [Accepted: 03/29/2020] [Indexed: 06/11/2023]
Abstract
Catalyzed H2O2 propagations (CHP) have demonstrated great potential in the remediation of chlorinated aliphatic hydrocarbons (CAHs) like trichloroethene (TCE) contaminated groundwater. However, the importation of highly unstable H2O2 into subsurface environment remains challenging. In this work, the in-situ H2O2 generation reaction between glucose oxidase (GOD) and glucose was applied in combination with Fe(II) to form the modified Fenton system (GMFs) and its performance in TCE oxidative degradation was investigated. The influence of reactant concentration as well as environmental factors like temperature and pH on the kinetics of TCE oxidation in GMFs were studied. At optimized conditions, about 78% TCE were removed within 8 h in GMFs, which remained effective over the temperature range of 15-30 °C and pH range of 3.6-6.0 (in acetate buffer). The in-situ H2O2 and OH generation capacity of GMFs were further investigated to elucidate their functional mechanism on TCE oxidation. Intermediate and product analysis indicated the near-complete release of chloride ion by TCE oxidation with few organic chlorinated intermediates detected. This work reveals the potential of GMFs for CAHs contaminated groundwater remediation through in-situ generation of reactive oxygen species.
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Affiliation(s)
- Yao Huang
- School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, China
| | - Hui Liu
- School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
| | - Shan Liu
- School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, China
| | - Cui Li
- School of Environmental Studies, China University of Geosciences, 388 Lumo Road, Wuhan, 430074, China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
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6
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Classification of BOF Slag by Data Mining Techniques According to Chemical Composition. SUSTAINABILITY 2020. [DOI: 10.3390/su12083301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the process of converting pig iron into steel, some co-products are generated—among which, basic oxygen furnace (BOF) slag is highlighted due to the great amount generated (about 126 kg of BOF slag per ton of steel grade). Great efforts have been made throughout the years toward finding an application to minimize the environmental impact and to increase sustainability while generating added value. Finding BOF slag valorization is difficult due to its heterogeneity, strength, and overall swallowing, which prevents its use in civil engineering projects. This work is focused on trying to resolve the heterogeneity issue. If many different types of steel are manufactured, then different types of slag could also be generated, and for each type of BOF slag, there is an adequate valorization option. Not all of the slag can be valorized, but it can be a tool for reducing the amount that must go to landfill and to minimize the environmental impact. An analysis by means of data mining techniques allows a classification of BOF slag to be obtained, and each one of these types has a better adjustment to certain valorization alternatives. In the plant used as an example of the application of these studies, eight different slag clusters were obtained, which were then linked to their different potential applications with the aim of increasing the amount valorized.
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7
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Experimental Study on the Optimum Preparation of Bentonite–Steel Slag Composite Particles. SUSTAINABILITY 2019. [DOI: 10.3390/su12010018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Novel multifunctional adsorbent bentonite–steel slag composite particles (BSC) were developed for highly efficient and synergistic treatment of heavy metal ions in acid mine drainage (AMD). Single-factor experiments were performed to examine the influence of different parameters on the adsorption effect, alkalinity release quantity, and loss rate of the composite particles. Based on these results, an L9(43) orthogonal experiment was carried out, and the optimum levels and order of the factors were determined by range analysis. Finally, the optimum preparation process of the composite particles was determined: a bentonite–steel slag proportion of 5:5, Na2CO3 content of 5%, aging time of 12 h, calcination particle size of 2 mm, calcination temperature of 500 °C, and calcination time of 60 min. The isothermal adsorption of optimum BSC fit well with Langmuir and Brunauer–Emmett–Teller (BET) isotherms ( R 2 R 2 > 0.997). A synergistic adsorption–coagulation effect occurs, leading to the appearance of multiple layers locally on the surface of BSC, which satisfies the BET model. To understand the preparation mechanism of the BSC, bentonite, steel slag, uncalcined BSC, and the optimum BSC were characterized using scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area analysis, X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The results indicate that calcination led to an increase in the average pore radius, total pore volume, and specific surface area (SBET) in the optimum BSC; numerous pores were present on its layered surface. Although the layer spacing increased after calcination, the structure of the dioctahedra remained unchanged. Exchangeable Na+, montmorillonite, and alkaline components were present between the optimum BSC layers. Water and impurities were removed after calcination. The BSC not only released an alkalinity-neutralising acid but also induced a synergistic adsorption–coagulation effect that removed heavy metal ions. It is an excellent multifunctional protective material for the mining environment, that can treat AMD-containing heavy metal ions.
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8
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Liu Y, Cheng M, Liu Z, Zeng G, Zhong H, Chen M, Zhou C, Xiong W, Shao B, Song B. Heterogeneous Fenton-like catalyst for treatment of rhamnolipid-solubilized hexadecane wastewater. CHEMOSPHERE 2019; 236:124387. [PMID: 31336240 DOI: 10.1016/j.chemosphere.2019.124387] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 07/13/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
The treatment of wastewater containing hydrophobic organic pollutants solubilized by surfactants is of great environmental importance. In this work, the removal of rhamnolipid-solubilized hexadecane via a salicylic acid-methanol-acetone modified steel converter slag (SMA-SCS) catalyzed Fenton-like process was studied. First, we investigated the adsorption of rhamnolipid and hexadecane onto SCS and SMA-modified SCS. Compared to that of SCS, SMA-SCS exhibited better adsorption performance with maximum adsorption capacities of 0.23 and 0.28 mg/g for hexadecane and rhamnolipid, respectively. Degradation experiments showed that hexadecane was more readily degraded by the Fenton-like process than rhamnolipid. Up to 81.1% of hexadecane removal was achieved over 20 g/L of SMA-SCS within 24 h, whereas only 36% of rhamnolipid was degraded. On the other hand, the results indicated that increased rhamnolipid concentration had a negative effect on the degradation of hexadecane. During the oxidation reaction, the pH value of solution remained between 6.0 and 6.72. All these results demonstrated that the SMA-SCS/H2O2 Fenton-like process could be a cost-effective and promising approach for the treatment of surfactant-solubilized hydrophobic organic compounds.
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Affiliation(s)
- Yang Liu
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Min Cheng
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Zhifeng Liu
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China.
| | - Hua Zhong
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430070, China.
| | - Ming Chen
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Chengyun Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Weiping Xiong
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Binbin Shao
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
| | - Biao Song
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan, 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan, 410082, China
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9
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Removal of Pb(II) from Acid Mine Drainage with Bentonite-Steel Slag Composite Particles. SUSTAINABILITY 2019. [DOI: 10.3390/su11164476] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Abandoned lead and zinc (Pb-Zn) mines around the world produce large amounts of acid mine drainage (AMD) containing Pb(II), which is toxic and accumulates in the environment and in living organisms. Bentonite-steel slag composite particles (BSC) are a new type of acid mine drainage (AMD) treatment material that can remove heavy metal ions and reduce acidity. To date, there have been no reports on the treatment of Pb(II)-containing AMD using BSC. Therefore, the effects of pH, reaction time, temperature, and Pb(II) concentration on the adsorption of Pb(II) onto BSC were studied. Moreover, the BSC before and after the reaction, as well as the precipitation after the reaction, were characterized by scanning electron microscopy and X-ray diffraction analyses. The effect of pH on the adsorption process is similar to that of the formation of soluble and insoluble hydrolysates of Pb(II) on pH. The adsorption mechanism includes ion exchange, complexation, precipitation, and synergistic adsorption–coagulation effect. Adsorption kinetics are best-fit with the pseudo-second order kinetics model ( R 2 > 0.98). Furthermore, the total adsorption rate is controlled by liquid film diffusion and in-particle diffusion, the liquid film diffusion rate being higher than the in-particle diffusion rate. The isothermal adsorption of Pb(II) onto BSC fit well with Langmuir and Brunauer Emmett Teller (BET) isotherms ( R 2 > 0.995), and both single layer adsorption and local multilayer adsorption were observed. Thermodynamic analysis revealed that the adsorption process is spontaneous and endothermic, and that the degree of freedom increases with time. In summary, this study provides a theoretical basis for the use of BSC in treating AMD containing Pb(II).
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Han J, Xin J, Zheng X, Kolditz O, Shao H. Remediation of trichloroethylene-contaminated groundwater by three modifier-coated microscale zero-valent iron. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:14442-14450. [PMID: 27068901 DOI: 10.1007/s11356-016-6368-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/29/2016] [Indexed: 06/05/2023]
Abstract
Building a microscale zero-valent iron (mZVI) reaction zone is a promising in situ remediation technology for restoring groundwater contaminated by trichloroethylene (TCE). In order to determine a suitable modifier that could not only overcome gravity sedimentation of mZVI but also improve its remediation efficiency for TCE, the three biopolymers xanthan gum (XG), guargum (GG), and carboxymethyl cellulose (CMC) were employed to coat mZVI for surface modification. The suspension stability of the modified mZVI and its TCE removal efficiency were systematically investigated. The result indicated that XG as a shear-thinning fluid showed the most remarkable efficiency of preventing mZVI from gravity sedimentation and enhancing the TCE removal efficiency by mZVI. In a 480-h experiment, the presence of XG (3 g L(-1)) increased the TCE removal efficiency by 31.85 %, whereas GG (3 g L(-1)) and CMC (3 g L(-1)) merely increased by 15.61 and 9.69 % respectively. The pH value, Eh value, and concentration of ferrous ion as functions of the reaction time were recorded in all the reaction systems, which indicated that XG worked best in buffering the pH value of the solution and inhibiting surface passivation of mZVI.
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Affiliation(s)
- Jun Han
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Qingdao, 266100, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Jia Xin
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Qingdao, 266100, China
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Xilai Zheng
- Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Qingdao, 266100, China.
- College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Olaf Kolditz
- Helmholtz Center for Environmental Research UFZ/TU Dresden, 034202, Leipzig, Germany
| | - Haibing Shao
- Helmholtz Center for Environmental Research UFZ/TU Dresden, 034202, Leipzig, Germany
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11
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Rajic L, Nazari R, Fallahpour N, Alshawabkeh AN. Electrochemical degradation of trichloroethylene in aqueous solution by bipolar graphite electrodes. JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 2016; 4:197-202. [PMID: 26955517 PMCID: PMC4778262 DOI: 10.1016/j.jece.2015.10.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this study, we tested the use of the bipolar electrodes to enhance electrochemical degradation of trichloroethylene (TCE) in an undivided, flow-through electrochemical reactor. The bipolar electrode forms when an electrically conductive material polarizes between feeder electrodes that are connected to a direct current source and, therefore, creates an additional anode/cathode pair in the system. We hypothesize that bipolar electrodes will generate additional oxidation/reduction zones to enhance TCE degradation. The graphite cathode followed by graphite anode sequence were operated without a bipolar electrode as well as with one and two bipolar graphite electrodes. The system without bipolar electrodes degraded 29% of TCE while the system with one and two bipolar electrodes degraded 38% and 66% of TCE, respectively. It was found that the removal mechanism for TCE in bipolar mode includes hydrodechlorination at the feeder cathode, and oxidation through reaction with peroxide. The results show that the bipolar electrodes presence enhance TCE removal efficiency and rate and imply that they can be used to improve electrochemical treatment of contaminated groundwater.
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12
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Chen KF, Chang YC, Liu KY. A kinetic and mechanistic study of the degradation of 1,2-dichloroethane and methyl tert-butyl ether using alkaline-activated persulfate oxidation. RSC Adv 2016. [DOI: 10.1039/c6ra16050f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alkaline-activated persulfate accelerates the degradation of 1,2-dichloroethane (1,2-DCA) while the rate of degradation of methyl tert-butyl ether (MTBE) in alkaline-activated persulfate system is decreased.
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Affiliation(s)
- Ku-Fan Chen
- Department of Civil Engineering
- National Chi Nan University
- Nantou 54561
- Taiwan
| | - Yu-Chen Chang
- Department of Civil Engineering
- National Chi Nan University
- Nantou 54561
- Taiwan
| | - Kuan-Yu Liu
- Department of Civil Engineering
- National Chi Nan University
- Nantou 54561
- Taiwan
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13
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Rajic L, Fallahpour N, Alshawabkeh AN. Impact of electrode sequence on electrochemical removal of trichloroethylene from aqueous solution. APPLIED CATALYSIS. B, ENVIRONMENTAL 2015; 174-175:427-434. [PMID: 25931774 PMCID: PMC4410430 DOI: 10.1016/j.apcatb.2015.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The electrode sequence in a mixed flow-through electrochemical cell is evaluated to improve the hydrodechlorination (HDC) of trichloroethylene (TCE) in aqueous solutions. In a mixed (undivided) electrochemical cell, oxygen generated at the anode competes with the transformation of target contaminants at the cathode. In this study, we evaluate the effect of placing the anode downstream from the cathode and using multiple electrodes to promote TCE reduction. Experiments with a cathode followed by an anode (C→A) and an anode followed by a cathode (A→C) were conducted using mixed metal oxide (MMO) and iron as electrode materials. The TCE removal rates when the anode is placed downstream of the cathode (C→A) were 54% by MMO→MMO, 64% by MMO→Fe and 87% by Fe→MMO sequence. Removal rates when the anode is placed upstream of the cathode (A→C) were 38% by MMO→MMO, 58% by Fe→MMO and 69% by MMO→Fe sequence. Placing the anode downstream of the cathode positively improves (by 26%) the degradation of aqueous TCE in a mixed flow-through cell as it minimizes the influence of oxygen generated at the MMO anode on TCE reduction at the cathode. Furthermore, placing the MMO anode downstream of the cathode neutralizes pH and redox potential of the treated solution. Higher flow velocity under the C→A setup increases TCE mass flux reduction rate. Using multiple cathodes and an iron foam cathode up stream of the anode increase the removal rate by 1.6 and 2.4 times, respectively. More than 99% of TCE was removed in the presence of Pd catalyst on carbon and as an iron foam coating. Enhanced reaction rates found in this study imply that a mixed flow-through electrochemical cell with multiple cathodes up stream of an anode is an effective method to promote the reduction of TCE in groundwater.
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Affiliation(s)
- Ljiljana Rajic
- Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States
| | - Noushin Fallahpour
- Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States
| | - Akram N. Alshawabkeh
- Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering, 360 Huntington Avenue, Boston, MA 02115, United States
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Rajic L, Fallahpour N, Yuan S, Alshawabkeh AN. Electrochemical transformation of trichloroethylene in aqueous solution by electrode polarity reversal. WATER RESEARCH 2014; 67:267-75. [PMID: 25282093 PMCID: PMC4262522 DOI: 10.1016/j.watres.2014.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 05/12/2023]
Abstract
Electrode polarity reversal is evaluated for electrochemical transformation of trichloroethylene (TCE) in aqueous solution using flow-through reactors with mixed metal oxide electrodes and Pd catalyst. The study tests the hypothesis that optimizing electrode polarity reversal will generate H2O2 in Pd presence in the system. The effect of polarity reversal frequency, duration of the polarity reversal intervals, current intensity and TCE concentration on TCE removal rate and removal mechanism were evaluated. TCE removal efficiencies under 6 cycles h(-1) were similar in the presence of Pd catalyst (50.3%) and without Pd catalyst (49.8%), indicating that Pd has limited impact on TCE degradation under these conditions. The overall removal efficacies after 60 min treatment under polarity reversal frequencies of 6, 10, 15, 30 and 90 cycles h(-1) were 50.3%, 56.3%, 69.3%, 34.7% and 23.4%, respectively. Increasing the frequency of polarity reversal increases TCE removal as long as sufficient charge is produced during each cycle for the reaction at the electrode. Electrode polarity reversal shifts oxidation/reduction and reduction/oxidation sequences in the system. The optimized polarity reversal frequency (15 cycles h(-1) at 60 mA) enables two reaction zones formation where reduction/oxidation occurs at each electrode surface.
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Affiliation(s)
- Ljiljana Rajic
- Civil and Environmental Engineering Department, Northeastern University, Boston, MA 02115, USA
| | - Noushin Fallahpour
- Civil and Environmental Engineering Department, Northeastern University, Boston, MA 02115, USA
| | - Songhu Yuan
- Civil and Environmental Engineering Department, Northeastern University, Boston, MA 02115, USA; State Key Lab of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, PR China
| | - Akram N Alshawabkeh
- Civil and Environmental Engineering Department, Northeastern University, Boston, MA 02115, USA.
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Gan S, Ng HK. Evaluation of in situ catalysed hydrogen peroxide propagation (CHP) for phenanthrene and fluoranthene removals from soil and its associated impacts on soil functionality. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:2888-2897. [PMID: 24151025 DOI: 10.1007/s11356-013-2207-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 09/30/2013] [Indexed: 06/02/2023]
Abstract
Extensive contamination of soils by highly recalcitrant contaminants such as polycyclic aromatic hydrocarbons (PAHs) is an environmental problem arising from rapid industrialisation. This work focusses on the remediation of soil contaminated with 3- and 4-aromatic ring PAHs (phenanthrene (PHE) and fluoranthene (FLUT)) through catalysed hydrogen peroxide propagation (CHP). In the present work, the operating parameters of the CHP treatment in packed soil column was optimised with central composite design (H2O2/soil 0.081, Fe(3+)/soil 0.024, sodium pyrophosphate (SP)/soil 0.024, pH of SP solution 7.73). The effect of contaminant aging on PAH removals was also investigated. Remarkable oxidative PAH removals were observed for the short aging and extended aging period (up to 86.73 and 70.61 % for PHE and FLUT, respectively). The impacts of CHP on soil biological, chemical and physical properties were studied for both spiked and aged soils. Overall, the soil functionality analyses after the proposed operating condition demonstrated that the values for soil respiration, electrical conductivity, pH and iron precipitation fell within acceptable limits, indicating the compatibility of the CHP process with land restoration.
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