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Li W, Yang S, Wang Y, Peng C, Li Y, Tao E. Selective adsorption of Cu(II) on amino-modified alginate-based aerogel: As a catalyst for the degradation of organic contaminant. Int J Biol Macromol 2024:134700. [PMID: 39142492 DOI: 10.1016/j.ijbiomac.2024.134700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 08/04/2024] [Accepted: 08/11/2024] [Indexed: 08/16/2024]
Abstract
In this study, amino-modified graphene oxide(NGO) was prepared by introducing amino functional groups. Based on the cross-linking between Ca(II) and sodium alginate (SA), associated with dense slit-like pore resulted from the nano-sheet accumulation of NGO and montmorillonite (MMT), composite aerogels (NGM) with stable pore structure were constructed, thus it realized the selective recovery of hydrated copper ions in complex wastewater systems. Raman analysis and density functional theory calculation confirmed the construction of amino-modified defect GO and significantly improved its chemical reactivity, which laid the foundation for the construction of slit pore structure of NGM (SEM can confirm). At the same time, it proposed that the good selective adsorption of Cu(II) on NGM was related to the synergism of strong electrostatic force, ion exchange and complexation based on the characterizations of FT-IR and XPS. In order to realize the value-added utilization of NGM aerogel (NGMC) after adsorbing Cu(II), NGMC was used as a catalyst to degrade organic pollutants in wastewater. Systematic experiments shown that NGMC can degrade organic pollutants with a degradation efficiency >80 %. In summary, NGM had a broad application prospect for selective recovery of Cu(II) from complex wastewater systems without second pollution.
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Affiliation(s)
- Wenhui Li
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou 121013, Liaoning, China
| | - Shuyi Yang
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou 121013, Liaoning, China
| | - Yuanfei Wang
- Liaoning Huadian Environmental Testing Co., LTD, Jinzhou 121013, Liaoning, China
| | - Chong Peng
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
| | - Yun Li
- Chemistry & Chemical Engineering of College Yantai University, Yantai 264005, Shandong, China.
| | - E Tao
- Liaoning Key Laboratory for Chemical Clean Production, Liaoning Key Laboratory for Surface Functionalization of Titanium Dioxide Powder, Institute of Ocean Research, Institute Environmental Research, College of Chemistry and Material Engineering, Bohai University, Jinzhou 121013, Liaoning, China.
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2
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Zhang Y, Wu P, Zhu J, Liao P, Niyuhire E, Fan F, Mao W, Dong L, Zheng R, Li Y. Investigation of the migration of natural organic matter-iron-antimony nano-colloids in acid mine drainage. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170666. [PMID: 38316310 DOI: 10.1016/j.scitotenv.2024.170666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/19/2024] [Accepted: 02/01/2024] [Indexed: 02/07/2024]
Abstract
Colloids can potentially affect the efficacy of traditional acid mine drainage (AMD) treatment methods such as precipitation and filtration. However, it is unclear how colloids affect antimony (Sb) migration in AMD, especially when natural organic matter (NOM) is present. To conduct an in-depth investigation on the formation and migration behavior of NOM, iron (Fe), Sb and NOM-Fe-Sb colloids in AMD, experiments were performed under simulated AMD conditions. The results demonstrate significant variations in the formation of NOM-Fe-Sb colloids (1-3-450 nm) as the molar ratio of carbon to iron (C/Fe) increases within acidic conditions (pH = 3). Increasing the C/Fe molar ratio from 0.1 to 1.2 resulted in a decrease in colloid formation but an increase in particulate fraction. The distribution of colloidal Sb, Sb(III), and Fe(III) within the NOM-Fe-Sb colloids decreased from 68 % to 55 %, 72 % to 57 %, and 68 % to 55 %, respectively. Their distribution in the particulate fraction increased from 28 % to 42 %, 21 % to 34 %, and 8 % to 27 %. XRD, FTIR, and SEM-EDS analyses demonstrated that NOM facilitates the formation and crystallization of Fe3O4 and FeSbO4 crystalline phases. The formation of the colloids depended on pH. Our results indicate that NOM-Fe-Sb colloids can form when the pH ≤ 4, and the proportion of colloidal Sb fraction within the NOM-Fe-Sb colloids increased from 9 % to a maximum of 73 %. Column experiments show that the concentration of NOM-Fe-Sb colloids reaches its peak and remains stable at approximately 3.5 pore volumes (PVs), facilitating the migration of Sb in the porous media. At pH ≥ 5, stable NOM-Fe-Sb colloids do not form, and the proportion of colloidal Sb fraction decreases from 7 % to 0 %. This implies that as pH increases, the electrostatic repulsion between colloidal particles weakens, resulting in a reduction in the colloidal fraction and an increase in the particulate fraction. At higher pH values (pH ≥ 5), the repulsive forces between colloidal particles nearly disappear, promoting particle aggregation. The findings of this study provide important scientific evidence for understanding the migration behavior of NOM-Fe-Sb colloids in AMD. As the pH gradually shifts from acidic to near-neutral pH during the remediation process of AMD, these results could be applied to develop new strategies for this purpose.
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Affiliation(s)
- Yuqin Zhang
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Pan Wu
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Jian Zhu
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China.
| | - Peng Liao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
| | - Elias Niyuhire
- Ecole Normale Supérieure, Département des Sciences Naturelles, Centre de Recherche en Sciences et de Perfectionnement Professionnel, Boulevard Mwezi Gisabo, B.P.: 6983 Bujumbura, Burundi
| | - Feifei Fan
- Guizhou Institute of Soil and Fertilizer, Guiyang 550006, China
| | - Wenjian Mao
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Lisha Dong
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Ruyi Zheng
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment, Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China
| | - Yi Li
- Guizhou Institute of Technology, Guiyang 550003, China
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Yang Z, Zhou H, Zhang X, Ma X, Zang X, Ding Y, Zhang J, He D. Simultaneous chelated heavy metals removal and sludge recovery through titanium coagulation: From waste to resource. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168821. [PMID: 38016569 DOI: 10.1016/j.scitotenv.2023.168821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/07/2023] [Accepted: 11/22/2023] [Indexed: 11/30/2023]
Abstract
Green methods for chelated heavy metals treatment and recovery are essential for coordinated development of resources and environment. Herein, a simple and competent method, titanium salt (TiCl4) coagulation was developed to remove and recycle chelated heavy metals. Our results revealed that this method proved to be effective for metals-citrate [Cu(II), Ni(II), Zn(II) and Cr(VI)], achieving removal efficiencies of 95 %, 92 %, 99 %, and 99 % within 30 min, surpassing direct alkaline precipitation and well-used Fe(III) coagulation. Whereafter, the copper-containing sludge was successfully transformed into copper-doped titanium dioxide (TiO2) photocatalysts by facile calcination. Through comprehensively investigating physicochemical properties by a suite of characterization techniques, we confirmed that doping of Cu induced bandgap narrowing, high specific surface area as well as the formation of oxygen vacancy. Accordingly, the recycling photocatalysts showed remarkable enhanced photocatalytic performance than the pristine TiO2, achieving improvement in the degradation efficiency of 82 %, 61 % and 67 % for carbamazepine(CBZ), bisphenol A (BPA) and methyl orange (MO). In addition, both radical (OH and O2-) and non-radical (1O2 and h+) pathways synergistically contributed to the removal of organic pollutants during photocatalysis. Ultimately, based on economic feasibility assessment and life cycle assessment (LCA), the copper-containing titanium coagulation sludge reuse for photocatalyst could bring lower carbon emissions, reduced environmental risks and higher economic benefits. The elucidation of this study provides new insights into the removal and recycle of chelated heavy metals from wastewater by using an environment-friendly and cost-effective method.
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Affiliation(s)
- Zhengheng Yang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
| | - Hongbo Zhou
- Shenzhen Pangu Environmental Protection Technology Co. Ltd, Shenzhen 518055, PR China
| | - Xinfei Zhang
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Xiaoming Ma
- Shenzhen Pangu Environmental Protection Technology Co. Ltd, Shenzhen 518055, PR China
| | - Xi Zang
- Guangdong Kaitian Environmental Governance Co. Ltd, Zhuhai 519000, PR China
| | - Yuxin Ding
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Jiafeng Zhang
- National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals, School of Metallurgy and Environment, Central South University, Changsha 410083, PR China.
| | - Di He
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
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Wu Y, Wang H, Du J, Si Q, Zhao Q, Jia W, Wu Q, Guo WQ. Enhanced Oxidation of Organic Compounds by the Ferrihydrite-Ferrate System: The Role of Intramolecular Electron Transfer and Intermediate Iron Species. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:16662-16672. [PMID: 37782530 DOI: 10.1021/acs.est.3c05798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Previous studies mostly held that the oxidation capacity of ferrate depends on the involvement of intermediate iron species (i.e., FeIV/FeV), however, the potential role of the metastable complex was disregarded in ferrate-based heterogeneous catalytic oxidation processes. Herein, we reported a complexation-mediated electron transfer mechanism in the ferrihydrite-ferrate system toward sulfamethoxazole (SMX) degradation. A synergy between intermediate FeIV/FeV oxidation and the intramolecular electron transfer step was proposed. Specifically, the conversion of phenyl methyl sulfoxide (PMSO) to methyl phenyl sulfone (PMSO2) suggested that FeIV/FeV was involved in the oxidation of SMX. Moreover, based on the in situ Raman test and chronopotentiometry analysis, the formation of the metastable complex of ferrihydrite/ferrate was found, which possesses higher oxidation potential than free ferrate and could achieve the preliminary oxidation of organics via the electron transfer step. In addition, the amino group of SMX could complex with ferrate, and the resulting metastable complex of ferrihydrite/ferrate would combine further with SMX molecules, leading to intramolecular electron transfer and SMX degradation. The ferrate loss experiments suggested that ferrihydrite could accelerate the decomposition of ferrate. Finally, the effects of pH value, anions, humic acid, and actual water on the degradation of SMX by ferrihydrite-ferrate were also revealed. Overall, ferrihydrite demonstrated high catalytic capacity, good reusability, and nontoxic performance for ferrate activation. The ferrihydrite-ferrate process may be a green and promising method for organic removal in wastewater treatment.
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Affiliation(s)
- Yaohua Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Huazhe Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Juanshan Du
- KENTECH Institute for Environmental & Climate Technology, Korea Institute of Energy Technology (KENTECH), Naju 58330, Korea
| | - Qishi Si
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qi Zhao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wenrui Jia
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qinglian Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Wan-Qian Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China
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Cho DW, Chon CM, Yim GJ, Ryu J, Jo H, Kim SJ, Jang JY, Song H. Adsorption of potentially harmful elements by metal-biochar prepared via Co-pyrolysis of coffee grounds and Nano Fe(III) oxides. CHEMOSPHERE 2023; 319:136536. [PMID: 36167204 DOI: 10.1016/j.chemosphere.2022.136536] [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: 06/02/2022] [Revised: 09/05/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Nano Fe(III) oxide (FO) was used as an amendment material in CO2-assisted pyrolysis of spent coffee grounds (SCG) and its impacts on the syngas (H2 & CO) generation and biochar adsorptive properties were investigated. Amendment of FO led to 153 and 682% increase of H2 and CO in pyrolytic process of SCG, respectively, which is deemed to arise from enhanced thermal cracking of hydrocarbons and oxygen transfer reaction mediated by FO. Incorporation of FO successfully created porous structure in the produced biochar. The adsorption tests revealed that the biochar exhibited bi-functional capability to remove both positively charged Cd(II) and Ni(II), and negatively charged Sb(V). The adsorption of Cd(II) and Ni(II) was hardly deteriorated in the multiple adsorption cycles, and the adsorption of Sb(V) was further enhanced through formation of surface ternary complexes. The overall results demonstrated nano Fe(III) oxide is a promising amendment material in CO2-assisted pyrolysis of lignocellulosic biomass for enhancing syngas generation and producing functional biochar.
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Affiliation(s)
- Dong-Wan Cho
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Chul-Min Chon
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Gil-Jae Yim
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Jungho Ryu
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Hwanju Jo
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Sun-Joon Kim
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Jeong-Yun Jang
- Mineral Resources Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea; Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
| | - Hocheol Song
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
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6
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Li J, Chen M, Yang X, Zhang L. Preparation of a novel hydrogel of sodium alginate using rural waste bone meal for efficient adsorption of heavy metals cadmium ion. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 863:160969. [PMID: 36549539 DOI: 10.1016/j.scitotenv.2022.160969] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 11/14/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Adsorption has been an important method for removing heavy metals from industrial wastewater. However, there has been a lack of an environmentally friendly, low-cost, biodegradable and easily recyclable material. China produces bones are not fully utilized leads to a waste of resources Therefore, efficient application of bone meal (BM) for remediation of contaminants in water would provide a promising alternative for resource utilization of bones. In this paper, we use a combination of BM and sodium alginate (SA) to prepare a novel BM/SA/calcium ion (BM/SA/Ca2+) double cross-linked composite hydrogel (BMSAH). Enhance the mechanical structure of SA while making the BM easy to recycle and reuse. The morphology and structure of the BMSAH were characterized using FT-IR spectroscopy and SEM-EDS. suggesting that the BMSAH can provide a larger specific surface area and high number of adsorption sites. The effects of the solution pH, ionic strength and contact time on the adsorption capacity of the BMSAH were investigated in depth, Under different conditions, BMSAH has a strong adsorption capacity of >90 %. XPS and FT-IR analysis showed that Cd2+ was adsorbed mainly via coordination interactions and hydrogen bonds with the carboxyl groups and nitrogen atoms in the BMSAH. A pseudo-second-order kinetic model, particle diffusion model and Isothermal adsorption lines indicate that the surface of the BMSAH is non-uniform suggesting that the adsorption of heavy metal ions by the BMSAH involves a combination of surface adsorption and intraparticle diffusion mechanisms, which is an overall chemical-physical adsorption process. In addition, the adsorption capacity of BMSAH remained above 90 % after three desorption cycles. Our work provides a new method for the preparation of a low-cost, high mechanical performance, biodegradable and easily recyclable physical hydrogels used for the removal of heavy metal ions.
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Affiliation(s)
- Jiapeng Li
- College of Resources and Environment, Qingdao Agricultural University, Qingdao 266005, PR China
| | - Mengxin Chen
- College of Resources and Environment, Qingdao Agricultural University, Qingdao 266005, PR China
| | - Xiaoqian Yang
- College of Resources and Environment, Qingdao Agricultural University, Qingdao 266005, PR China
| | - Lei Zhang
- College of Resources and Environment, Qingdao Agricultural University, Qingdao 266005, PR China.
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Li H, Li W, Li P, Yang P, Zhang T, Cheng Y. Influence of citrate/tartrate on chromite crystallization behavior and its potential environmental implications. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130155. [PMID: 36257108 DOI: 10.1016/j.jhazmat.2022.130155] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 09/01/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
The ferrite process has been developed to purify wastewater containing heavy metal ions and recycle valuable metals by forming chromium ferrite. However, organic matter has an important influence on the crystallization behavior and stability of chromite synthesized from chromium-containing wastewater. We focused on the influence and effect mechanism of two typical organic acid salts (citrate (CA) and tartrate (TA)) on the process of chromium mineralization. It was found that the presence of organic matter leads to the increase of the residual content of Cr in CA system (0.50 mmol/L) and TA system (0.61 mmol/L) in the solution, and the removal of chromium was mainly due to the surface adsorption of Fe(III) hydrolysate. The decreased crystallinity of mineralized products is ascribed to the completion of organic compounds with Fe(II) and Fe(III), which hinders the formation of ferrite precursors. There was bidentate and monodentate chelation between -COO- and metal ions in the CA system and TA system respectively, which resulted in a stronger affinity between CA and iron. This study provides the underlying mechanism for Cr(III) solid oxidation by the ferrite method in an organic matter environment and is of great significance to prevent and control chromium pollution in the environment.
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Affiliation(s)
- Hongzheng Li
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China
| | - Wen Li
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China.
| | - Pengxu Li
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China
| | - Peng Yang
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China
| | - Tingting Zhang
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China
| | - Yangjian Cheng
- School of Advanced Manufacturing, Fuzhou University, 1 Shuicheng Road, Jinjiang, Fujian 362251, PR China.
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Zhao T, Pan J, Mao C, Chen L, Li J, Shao H, Xu G. Enhanced decomplexation of Cu-EDTA and simultaneous removal of Cu(II) by electron beam irradiation accompanied with autocatalytic fenton-like reaction: Synergistic performance and mechanism. CHEMOSPHERE 2023; 313:137445. [PMID: 36495973 DOI: 10.1016/j.chemosphere.2022.137445] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/28/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Widely existing heavy metal complexes with high stability and poor biodegradability are intractable to be eliminated by conventional methods. In this study, electron beam (EB) irradiation characterized by rapidly producing strong oxidizing radicals was employed to effectively decompose Cu-ethylenediaminetetraacetic acid (Cu-EDTA) with almost complete elimination at 5 kGy. In terms of heavy metal removal, EB irradiation at relatively low doses was insufficient to remove copper ions, which was only 17.2% under 15 kGy. However, with the extra addition of 8 mM H2O2, such an irradiation dose could result in 99.0% copper ions removal. Mechanism analysis indicated that EB irradiation combined with spontaneously induced Fenton-like reactions were responsible for its excellent performance. The prime function of EB irradiation was to destroy the structure of Cu-EDTA with in-situ produced ·OH, and the subsequent released Cu-based intermediates could activate H2O2 to initiate autocatalytic chain reactions, correspondingly accelerating the degradation of complexes and the liberation of metal ions. Highly oxidative ·OH and O2·- were demonstrated as main active species acted on different positions of Cu-EDTA to realize gradual decarboxylation, synchronously generating low molecular weight compounds. XRD and XPS analysis showed that the released copper ions were mainly precipitated in the form of CuO, Cu(OH)2 and Cu2(OH)2CO3. In general, EB/H2O2 was an adoptable strategy for the disposal of such refractory heavy metal complexes.
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Affiliation(s)
- Tingting Zhao
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Jiali Pan
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Chengkai Mao
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Shanghai Institute of Applied Radiation, Shanghai University, 20 Chengzhong Road, Shanghai, 200444, China
| | - Lei Chen
- Shanghai Institute of Applied Radiation, Shanghai University, 20 Chengzhong Road, Shanghai, 200444, China
| | - Jiayuan Li
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Haiyang Shao
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai, 200444, PR China; Shanghai Institute of Applied Radiation, Shanghai University, 20 Chengzhong Road, Shanghai, 200444, China
| | - Gang Xu
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai, 200444, China; Key Laboratory of Organic Compound Pollution Control Engineering, Ministry of Education, Shanghai, 200444, PR China; Shanghai Institute of Applied Radiation, Shanghai University, 20 Chengzhong Road, Shanghai, 200444, China.
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