1
|
Hamdi FM, Ganbat N, Altaee A, Samal AK, Ibrar I, Zhou JL, Sharif AO. Hybrid and enhanced electrokinetic system for soil remediation from heavy metals and organic matter. J Environ Sci (China) 2025; 147:424-450. [PMID: 39003060 DOI: 10.1016/j.jes.2023.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/07/2023] [Accepted: 11/08/2023] [Indexed: 07/15/2024]
Abstract
The electrokinetic (EK) process has been proposed for soil decontamination from heavy metals and organic matter. The advantages of the EK process include the low operating energy, suitability for fine-grained soil decontamination, and no need for excavation. During the last three decades, enhanced and hybrid EK systems were developed and tested for improving the efficiency of contaminants removal from soils. Chemically enhanced-EK processes exhibited excellent efficiency in removing contaminants by controlling the soil pH or the chemical reaction of contaminants. EK hybrid systems were tested to overcome environmental hurdles or technical drawbacks of decontamination technologies. Hybridization of the EK process with phytoremediation, bioremediation, or reactive filter media (RFM) improved the remediation process performance by capturing contaminants or facilitating biological agents' movement in the soil. Also, EK process coupling with solar energy was proposed to treat off-grid contaminated soils or reduce the EK energy requirements. This study reviews recent advancements in the enhancement and hybrid EK systems for soil remediation and the type of contaminants targeted by the process. The study also covered the impact of operating parameters, imperfect pollution separation, and differences in the physicochemical characteristics and microstructure of soil/sediment on the EK performance. Finally, a comparison between various remediation processes was presented to highlight the pros and cons of these technologies.
Collapse
Affiliation(s)
- Faris M Hamdi
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia; Department of Civil Engineering, Jazan University, Jazan 82822, Saudi Arabia
| | - Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia.
| | - Akshaya K Samal
- Centre for Nano and Material Sciences, Jain University, Ramanagara, Bangalore, Karnataka 562 112, India
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, The University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Adel O Sharif
- School of Mechanical Sciences, Faculty of Engineering and Physical Sciences, University of Surrey, Australia
| |
Collapse
|
2
|
Hamdi FM, Altaee A, Alsaka L, Ibrar I, Al-Ejji M, Zhou J, Samal AK, Hawari AH. Iron slag/activated carbon-electrokinetic system with anolyte recycling for single and mixture heavy metals remediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172516. [PMID: 38636874 DOI: 10.1016/j.scitotenv.2024.172516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 04/02/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
The electrokinetic process has been proposed for in-situ soil remediation to minimize excavation work and exposure to hazardous materials. The precipitation of heavy metals in alkaline pH near the cathode is still challenging. Reactive filter media and enhancement agents have been used in electrokinetics to enhance the removal of heavy metals. This study investigated coupling industrial iron slag waste and iron slag-activated carbon reactive filter media with electrokinetic for a single and mixture of heavy metals treatment. Instead of using acid enhancement agents, the anolyte solution was recycled to neutralize the alkaline front at the cathode, reducing the operation cost and chemical use. Experiments were conducted for 2 and 3 weeks at 20 mA electric current. Copper removal increased from 3.11 % to 23 % when iron slag reactive filter media was coupled with electrokinetic. Copper removal increased to 70.14 % in the electrokinetic experiment with iron slag-activated carbon reactive filter media. The copper removal increased to 89.21 % when the anolyte solution was recycled to the cathode compartment. Copper removal reached 93.45 % when the reactive filter media-electrokinetic process with anolyte recirculation was extended to 3 weeks. The reactive filter media- an electrokinetic process with anolyte recycling was evaluated for removing copper, nickel, and zinc mixture, and results revealed 81.1 % copper removal, 89.04 % nickel removal, and 92.31 % zinc removal in a 3-week experiment. The greater nickel and zinc removal is attributed to their higher solubility than copper. The results demonstrated the cost-effectiveness and efficiency of the electrokinetic with iron slag-activated carbon reactive filter media with anolyte recirculation for soil remediation from heavy metals.
Collapse
Affiliation(s)
- Faris M Hamdi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia; Department of Civil Engineering, Jazan University, Jazan 82822, Saudi Arabia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia.
| | - Lilyan Alsaka
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Maryam Al-Ejji
- Center of Advanced Materials, Qatar University, PO Box 2713, Doha, Qatar
| | - John Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Akshaya K Samal
- Centre for Nano and Material Sciences, Jain University, Ramanagara, Bangalore 562 112, Karnataka, India
| | - Alaa H Hawari
- Department of Civil and Environmental Engineering, College of Engineering, Qatar University, PO Box 2713, Doha, Qatar
| |
Collapse
|
3
|
Pasciucco E, Pasciucco F, Castagnoli A, Iannelli R, Pecorini I. Removal of heavy metals from dredging marine sediments via electrokinetic hexagonal system: A pilot study in Italy. Heliyon 2024; 10:e27616. [PMID: 38515701 PMCID: PMC10955240 DOI: 10.1016/j.heliyon.2024.e27616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/04/2024] [Accepted: 03/04/2024] [Indexed: 03/23/2024] Open
Abstract
Among the several treatment options, electrokinetic (EK) remediation is recognized as an effective technique for the removal of heavy metals from low-permeability porous matrices. However, most of the EK decontamination research reported was performed on linear configuration systems at a laboratory scale. In this study, a series of experiments were performed on a pilot-scale system where the electrodes were arranged in a hexagonal configuration, to assess the improvement of the EK process in the removal of inorganic contaminants from sediments dredged in the harbor of Piombino, Italy. HNO3 was used as acid conditioning and both pH effect and treatment duration time were investigated. Sediment characterization and metal fractionation were also presented, in order to understand how the bioavailability of metals affects the process efficiency. The increase in pH due to the buffering capacity of the sediment in the sections close to the cathode favored the precipitation and accumulation of metals. However, the results highlighted that longer treatment times, combined with an efficient pH reduction, can improve treatment performance, resulting in high removal efficiencies for all the target metals considered (a percentage removal greater than 50% was reached for Cd, Ni, Pb, Cu and Zn). Compared to different EK configuration systems, the hexagonal configuration arrangement applied in our study provides better results for the remediation of dredged marine sediment.
Collapse
Affiliation(s)
- Erika Pasciucco
- Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy
| | - Francesco Pasciucco
- Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy
| | - Alessio Castagnoli
- Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy
| | - Renato Iannelli
- Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy
| | - Isabella Pecorini
- Department of Energy, Systems Territory and Construction Engineering, Via C.F. Gabba 22, Tuscany, University of Pisa, Pisa, 56122, Italy
| |
Collapse
|
4
|
Dhandapani P, Srinivasan V, Parthipan P, AlSalhi MS, Devanesan S, Narenkumar J, Rajamohan R, Ezhilselvi V, Rajasekar A. Development of an environmentally sustainable technique to minimize the sludge production in the textile effluent sector through an electrokinetic (EK) coupled with electrooxidation (EO) approach. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:81. [PMID: 38367190 DOI: 10.1007/s10653-023-01847-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/27/2023] [Indexed: 02/19/2024]
Abstract
This study presents an environmentally sustainable method for minimizing sludge production in the textile effluent sector through the combined application of electrokinetic (EK) and electrooxidation (EO) processes. AAS and XRF analyses reveal that utilizing acidic electrolytes in the EK method successfully eliminates heavy metals (Cu, Mn, Zn, and Cr) from sludge, demonstrating superior efficiency compared to alkaline conditions. In addition, the total removal efficiency of COD contents was calculated following the order of EK-3 (60%), EK-1 (51%) and EK-2 (34%). Notably, EK-3, leveraging pH gradient fluctuations induced by anolyte in the catholyte reservoir, outperforms other EK systems in removing COD from sludge. The EK process is complemented by the EO process, leading to further degradation of dye and other organic components through the electrochemical generation of hypochlorite (940 ppm). At an alkaline pH of 10.0, the color and COD removal were effectively achieved at 98 and 70% in EO treatment, compared to other mediums. In addition, GC-MS identified N-derivative residues at the end of the EO. This study demonstrates an integrated approach that effectively eliminates heavy metals and COD from textile sludge, combining EK with EO techniques.
Collapse
Affiliation(s)
- Perumal Dhandapani
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India
| | - Venkatesan Srinivasan
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India
| | - Punniyakotti Parthipan
- Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, 603 203, India
| | - Mohamad S AlSalhi
- Department of Physics and Astronomy, College of Science, King Saud University, P. O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Sandhanasamy Devanesan
- Department of Physics and Astronomy, College of Science, King Saud University, P. O. Box 2455, 11451, Riyadh, Saudi Arabia
| | - Jayaraman Narenkumar
- Department of Environmental and Water Resources Engineering, School of Civil Engineering (SCE), Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India
| | - Rajaram Rajamohan
- Organic Materials Synthesis Lab, School of Chemical Engineering, Yeungnam University, Gyeongsan-si, 38541, Republic of Korea.
| | - Varathan Ezhilselvi
- Indian Reference Materials (BND) Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi, 110012, India
| | - Aruliah Rajasekar
- Environmental Molecular Microbiology Research Laboratory, Department of Biotechnology, Thiruvalluvar University, Serkkadu, Vellore, Tamil Nadu, 632115, India.
- Adjunct Faculty, Department of Prothodontics, Saveetha Dental Collge and Hospital, Chennai, Tamil Nadu, 600 077, India.
| |
Collapse
|
5
|
Sun Z, Zhao M, Chen L, Gong Z, Hu J, Ma D. Electrokinetic remediation for the removal of heavy metals in soil: Limitations, solutions and prospection. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:165970. [PMID: 37572906 DOI: 10.1016/j.scitotenv.2023.165970] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/10/2023] [Accepted: 07/30/2023] [Indexed: 08/14/2023]
Abstract
Electrokinetic remediation (EKR) technology is a promising method to remove heavy metals from low permeability soil, because it is environmentally friendly, efficient and economical, and can realize in-situ remediation. In this paper, the basic principles and related physical and chemical phenomena of EKR are systematically summarized, and three limiting problems of EKR technology are put forward: the weak ability of dissolving metals, focusing effect, and energy consumption. There are many methods to solve these technical problems, but there is a lack of systematic summary of the causes of problems and solutions. Based on various enhanced EKR technologies, this paper summarizes the main ideas to solve the limiting problems. The advantages and disadvantages of each technology are compared, which has guiding significance for the development of new technology in the future. This paper also discusses the dissolution of residual heavy metals, which is rare in other articles. The energy consumption of EKR and the remediation effect are equally important, and both can be used as indicators for evaluating the feasibility of new technologies. This paper reviews the influence of various electric field conditions on power consumption, such as renewable energy supply, new electrode materials and electrode configurations, suitable voltage values and functional electrolytes. In addition, a variety of energy consumption calculation methods are also introduced, which are suitable for ohmic heat loss, energy distribution when there is non-target ion competition, and power consumption of specific ions in various metal ions. Researchers can make selective reference according to their actual situations. This paper also systematically introduces the engineering design and cost calculation of EKR, lists the research progress of some engineering cases and pilot-scale tests, analyzes the reasons why it is difficult to apply EKR technology in large-scale engineering at present, and puts forward the future research direction.
Collapse
Affiliation(s)
- Zeying Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Miaomiao Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Li Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Zhiyang Gong
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Junjie Hu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Degang Ma
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
| |
Collapse
|
6
|
Qu Z, Huang L, Guo M, Sun T, Xu X, Gao Z. Application of novel polypyrrole/melamine foam auxiliary electrode in promoting electrokinetic remediation of Cr(VI)-contaminated soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162840. [PMID: 36924972 DOI: 10.1016/j.scitotenv.2023.162840] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/22/2023] [Accepted: 03/09/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Zhengjun Qu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Lihui Huang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
| | - Mengmeng Guo
- Jinan Ecological and Environmental Monitoring Center, Jinan 250000, China
| | - Ting Sun
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Xiaoshen Xu
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Zhenhui Gao
- Institute of Eco-Environmental Forensics of Shandong University, Qingdao 266237, China
| |
Collapse
|
7
|
Maqbool T, Jiang D. Electrokinetic remediation leads to translocation of dissolved organic matter/nutrients and oxidation of aromatics and polysaccharides. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162703. [PMID: 36906032 DOI: 10.1016/j.scitotenv.2023.162703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/03/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Dissolved organic matter (DOM) in the sediment matrix affects contaminant remediation through consumption of oxidants and binding with contaminants. Yet the change in DOM during remediation processes, particularly during electrokinetic remediation (EKR), remains under-investigated. In this work, we elucidated the fate of sediment DOM in EKR using multiple spectroscopic tools under abiotic and biotic conditions. We found that EKR led to significant electromigration of the alkaline-extractable DOM (AEOM) toward the anode, followed by transformation of the aromatics and mineralization of the polysaccharides. The AEOM remaining in the cathode (largely polysaccharides) was resistant to reductive transformation. Limited difference was noted between abiotic and biotic conditions, indicating the dominance of electrochemical processes when relatively high voltages were applied (1-2 V/cm). The water-extractable organic matter (WEOM), in contrast, showed an increase at both electrodes, which was likely attributable to pH-driven dissociations of humic substances and amino acid-type constituents at the cathode and the anode, respectively. Nitrogen migrated with the AEOM toward the anode, but phosphorus remained immobilized. Understanding the redistribution and transformation of DOM could inform studies on contaminant degradation, carbon and nutrient availability, and sediment structural changes in EKR.
Collapse
Affiliation(s)
- Tahir Maqbool
- Department of Civil, Construction, and Environmental Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Daqian Jiang
- Department of Civil, Construction, and Environmental Engineering, The University of Alabama, Tuscaloosa, AL 35487, USA.
| |
Collapse
|
8
|
Abou-Shady A, Ali ME, Ismail S, Abd-Elmottaleb O, Kotp YH, Osman MA, Hegab RH, Habib AA, Saudi AM, Eissa D, Yaseen R, Ibrahim GA, Yossif TM, El-Araby H, Selim EMM, Tag-Elden MA, Elwa AES, El-Harairy A. Comprehensive review of progress made in soil electrokinetic research during 1993–2020, Part I: process design modifications with brief summaries of main output. SOUTH AFRICAN JOURNAL OF CHEMICAL ENGINEERING 2023. [DOI: 10.1016/j.sajce.2023.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
|
9
|
Gao Y, Wu P, Jeyakumar P, Bolan N, Wang H, Gao B, Wang S, Wang B. Biochar as a potential strategy for remediation of contaminated mining soils: Mechanisms, applications, and future perspectives. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 313:114973. [PMID: 35398638 DOI: 10.1016/j.jenvman.2022.114973] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/14/2022] [Accepted: 03/24/2022] [Indexed: 06/14/2023]
Abstract
Soil heavy metal contamination caused by mining activities is a global issue. These heavy metals can be enriched in plants and animals through the food chain, and eventually transferred to the human system and threatening public health. Biochar, as an environmentally friendly soil remediation agent, can effectively immobilize heavy metals in soil. However, most researchers concern more about the remediation effect and mechanism of biochar for industrial and agricultural contaminated soil, while related reviews focusing on mining soil remediation are limited. Furthermore, the remediation effect of soil in mining areas is affected by many factors, such as physicochemical properties of biochar, pyrolysis conditions, soil conditions, mining environment and application method, which can lead to great differences in the remediation effect of biochar in diverse mining areas. Therefore, it is necessary to systematically unravel the relevant knowledge of biochar remediation, which can also provide a guide for future studies on biochar remediation of contaminated soils in mining areas. The present paper first reviews the negative effects of mining activities on soil and the advantages of biochar relative to other remediation methods, followed by the mechanism and influencing factors of biochar on reducing heavy metal migration and bioavailability in mining soil were systematically summarized. Finally, the main research directions and development trends in the future are pointed out, and suggestions for future development are proposed.
Collapse
Affiliation(s)
- Yining Gao
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Pan Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Karst Environment and Geohazard, Ministry of Natural Resources, Guiyang, 550025, Guizhou, China
| | - Paramsothy Jeyakumar
- Environmental Sciences, School of Agriculture and Environment, Massey University, Private Bag 11 222, Palmerston North, 4442, New Zealand
| | - Nanthi Bolan
- The Global Centre for Environmental Remediation, University of Newcastle, Callaghan, NSW, Australia
| | - Hailong Wang
- Biochar Engineering Technology Research Center of Guangdong Province, School of Environment and Chemical Engineering, Foshan University, Foshan, Guangdong, 528000, China
| | - Bin Gao
- Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL, USA
| | - Shengsen Wang
- College of Environmental Science and Engineering, Yangzhou University, Yangzhou, 225127, China
| | - Bing Wang
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, Guizhou, China; Key Laboratory of Karst Environment and Geohazard, Ministry of Natural Resources, Guiyang, 550025, Guizhou, China.
| |
Collapse
|
10
|
Zhao M, Ma D, Sun X, Wang Y, Wang Q. In situ removal of cadmium by short-distance migration under the action of a low-voltage electric field and granular activated carbon. CHEMOSPHERE 2022; 287:132208. [PMID: 34826910 DOI: 10.1016/j.chemosphere.2021.132208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Cd pollution in soil is a global environmental issue of great concern. The secondary release and low removal rate of Cd are obstacles to the use of adsorption techniques. To develop a sustainable and effective remediation technique, low-voltage direct current (DC) and granular activated carbon (GAC) were applied for in situ Cd removal. The results showed that a low-voltage gradient was more favourable than a high-voltage gradient for Cd removal. A voltage gradient of 0.2 V cm-1 acted as a driving force for Cd migration while limiting the side effects caused by DC. As an auxiliary enhancement measure, polarity exchange was effective in maintaining uniform distributions of soil moisture and temperature as well as a stable pH while improving Cd removal by weakening inhibition caused by OH- generated at the cathodes. The average removal rates of total and bioavailable Cd were 61.05% and 76.96%, respectively. The potential mobility of Cd in soil was assessed by the mobility factor (MF). The MF was lowered from 42.66% to 8.96%, indicating that the risks of Cd mobility were reduced to low levels. The energy consumption and utilization efficiency of the method were 5.65 KWh m-3 and 11.25, respectively. The energy utilization efficiency was significantly higher than the efficiencies of other methods that use DC to improve Cd removal. The results suggested that the in situ removal of Cd by low-voltage DC and GAC was efficient and avoided the secondary release of Cd.
Collapse
Affiliation(s)
- Miaomiao Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| | - Degang Ma
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| | - Xianfu Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| | - Yuxin Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| | - Qiji Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| |
Collapse
|
11
|
Ghobadi R, Altaee A, Zhou JL, Karbassiyazdi E, Ganbat N. Effective remediation of heavy metals in contaminated soil by electrokinetic technology incorporating reactive filter media. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148668. [PMID: 34225154 DOI: 10.1016/j.scitotenv.2021.148668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 06/15/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Soil contamination is increasingly a global problem with serious implications for human health. Among different soil decontamination approaches, electrokinetic (EK) remediation is a relatively new technology for treating organic and inorganic contaminants in soil. This research aims to develop an enhanced EK treatment method incorporating a compost-based reactive filter media (RFM) with the advantages of low-cost and strong affinity for heavy metals and test and improve the treatment efficiency for multiple heavy metals in natural soil. A series of EK operations were performed to investigate the performance of EK-RFM under different operating conditions such as the electric current and voltage, processing time, and the amount of RFM. The electric current and treatment time demonstrated a significant positive impact on removing Zn, Cd and Mn ions while changing the amount of RFM had an insignificant impact on the efficiency of heavy metals removal. Overall, 51.6%-72.1% removal of Zn, Cd, and Mn was achieved at 30.00 mA of electric current and 14 days of treatment duration. The energy consumption of the EK process was 0.17 kWh kg-1. The soil organic matter adversely affected the mobilization and migration of heavy metals such as Cu and Pb during EK treatment. The results are valuable in optimizing the design of the EK-RFM system, which will extend its application to field-scale soil decontamination practices.
Collapse
Affiliation(s)
- Romina Ghobadi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia.
| | - Elika Karbassiyazdi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| |
Collapse
|
12
|
Ghobadi R, Altaee A, Zhou JL, McLean P, Ganbat N, Li D. Enhanced copper removal from contaminated kaolinite soil by electrokinetic process using compost reactive filter media. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123891. [PMID: 33254824 DOI: 10.1016/j.jhazmat.2020.123891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 08/17/2020] [Accepted: 08/30/2020] [Indexed: 06/12/2023]
Abstract
Electrokinetic (EK) remediation is a promising technology for soil decontamination, although basic pH in the soil close to cathode has constrained EK effectiveness due to heavy metal precipitation. This study aimed to enhance copper removal from kaolinite soil by integrating EK with compost (C) as recyclable reactive filter media (RFM) for the first time. Compost placed near the cathode served as an adsorbent to bind copper ions while buffering the advancement of the alkaline front in soil. The total copper removal rate increased from 1.03% in EK to 45.65% in EK-100%C under an electric potential of 10 V. Further experiments conducted by using biochar (BC) and compost/biochar (C + BC) mixture RFM at different ratios showed total Cu removal efficiency decreasing as EK-100%C > EK-(10%BC + 90%C) > EK-(20%BC + 80%C) > EK-(30%BC + 70%C) > EK. The application of a constant electric current of 20.00 mA further enhanced copper removal to 84.09% in EK-100%C although did not show significant enhancement in EK-(BC + C). The compost RFM was regenerated by acid extraction and then reused twice, achieving a total removal of 74.11%. The findings demonstrated compost as a promising and reusable RFM for the efficient removal of copper in contaminated soil.
Collapse
Affiliation(s)
- Romina Ghobadi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
| | - John L Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia.
| | - Peter McLean
- School of Electrical and Data Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia
| | - Namuun Ganbat
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW, 2007, Australia
| | - Donghao Li
- Department of Chemistry, MOE Key Laboratory of Biological Resources of Changbai Mountain & Functional Molecules, Yanbian University, Yanji, 133002, Jilin Province, PR China
| |
Collapse
|
13
|
Yadav S, Ibrar I, Altaee A, Samal AK, Ghobadi R, Zhou J. Feasibility of brackish water and landfill leachate treatment by GO/MoS 2-PVA composite membranes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 745:141088. [PMID: 32738694 DOI: 10.1016/j.scitotenv.2020.141088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/15/2020] [Accepted: 07/18/2020] [Indexed: 06/11/2023]
Abstract
Two-dimensional (2D) based layered materials with tunable chemical functionalities and surface charge properties have emerged for on-demand applications including membrane technology. However, the process control, time and energy-efficient production of non-swelling graphene oxide (GO) with retaining physicochemical properties are still challenging. In this work, we have fabricated highly ordered GO membrane on cellulose acetate supporting membrane filters of 1.2 μm pore size using molybdenum disulphide (MoS2) as a nano-spacer and polyvinyl alcohol (PVA) as an adhesive for the first time with limited swelling. The fabricated membranes were used for NaCl rejection and removal of toxic heavy metal ions, and the radioactive element from landfill leachate water. The introduction of hydrophilic PVA, thickness control using a various amount of nanospacer and graphene oxide played a vital role in the transport mechanism, permeability, and selectivity index. The composition of PVA and MoS2 in the coating solution was optimized to tune the d-spacing of graphene oxide layers. The newly developed composite membranes have 89% rejection rate to NaCl and 3.96 L/m2h water flux at low operating pressures of 5 bar. Also, the prepared membranes have a high rejection of multivalent metal ions in landfill leachate. 86.5% to 99.8% rejection rate of multivalent metal ions in landfill leachate was observed for the M3 (GO (10): MoS2 (10): PVA (0.5)) membrane. The excellent rejection performance is ascribed to the combined impact of size exclusion, ion adsorption, electrostatic interaction and Gibbs-Donnan exclusion mechanism. The excellent stability and high rejection rate even after 216 h of operation make the fabricated membranes promising for use in practical water separation applications.
Collapse
Affiliation(s)
- Sudesh Yadav
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ibrar Ibrar
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - Ali Altaee
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia.
| | | | - Romina Ghobadi
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| | - John Zhou
- Centre for Green Technology, School of Civil and Environmental Engineering, University of Technology Sydney, 15 Broadway, NSW 2007, Australia
| |
Collapse
|