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Mosai AK, Ndlovu G, Tutu H. Improving acid mine drainage treatment by combining treatment technologies: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 919:170806. [PMID: 38350575 DOI: 10.1016/j.scitotenv.2024.170806] [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: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/15/2024]
Abstract
The mining and processing of some minerals and coal result in the production of acid mine drainage (AMD) which contains elevated levels of sulfate and metals, which tend to pose serious environmental issues. There are different technologies that have been developed for the treatment of wastewater or AMD. However, there is no "one-size-fits-all" solution, hence a combination of available technologies should be considered to achieve effective treatment. In this review, AMD treatment technologies and the possible alignment in tandem of the different treatment technologies were discussed. The alignment was based on the target species of each technology and AMD composition. The choice of the technologies to combine depends on the quality of AMD and the desired quality of effluent depending on end use (e.g., drinking, industrial, irrigation or release into the environment). AMD treatment technologies targeting metals can be combined with membrane and/or ettringite precipitation technologies that focus on the removal of sulfates. Other technologies can be added to deal with the secondary waste products (e.g., sludge and brines) from the treatment processes. Moreover, some technologies such as ion exchange and adsorption can be added to target specific valuable elements in AMD. Such combinations have the potential to result in effective AMD treatment and minimum waste production, which are not easily achievable with the individual technologies. Overall, this review presents combinations of AMD treatment technologies which can work best together to produce optimal water quality and valuable products in a cost-effective manner.
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Affiliation(s)
- Alseno Kagiso Mosai
- Department of Chemistry, Faculty of Natural and Agricultural Sciences, University of Pretoria, Lynnwood Road, Pretoria 0002, South Africa.
| | - Gebhu Ndlovu
- Hydrometallurgy Division, Mintek, 200 Malibongwe drive, Private Bag X3015, Randburg 2125, South Africa
| | - Hlanganani Tutu
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Private Bag X3, Wits 2050, South Africa
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Liu X, Dong X, Chang S, Xu X, Li J, Pu H. Remediation of lead-contaminated groundwater by oyster shell powder-peanut shell biochar mixture. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:9599-9619. [PMID: 37776470 DOI: 10.1007/s10653-023-01756-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/08/2023] [Indexed: 10/02/2023]
Abstract
Groundwater pollution caused by lead ions has become a widespread issue worldwide due to the ever-increasing development of industrial activities. Such pollution poses significant threats to both humans and the environment. Oyster shell powder-peanut shell biochar mixture (OSP-PSB mixture) was used for lead-contaminated groundwater treatment by permeable reactive barrier (PRB) technology. Basic characteristics of materials proved that OSP-PSB mixture has good adsorption properties; OSP with particle sizes ranging from 0.85 to 1.18 mm was used in this research; according to engineering and adsorption characteristics, OSP-PSB mixture (5:1) showed excellent permeability (4.35 × 10-4 cm/s) and lead adsorption capacity(27 mg/g); long-term permeability of the OSP-PSB mixture slightly decreased over time and met the permeability requirements for PRB; the removal mechanisms of lead ions by OSP-PSB mixture include precipitation, surface complexation, ion exchange, and physical adsorption. The experiment results showed that the OSP-PSB mixture fulfills the actual project requirements of PRB.
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Affiliation(s)
- Xiaofeng Liu
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
| | - Xiaoqiang Dong
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, 030024, China.
| | - Shiqi Chang
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Xin Xu
- College of Construction Engineering, Jilin University, Jilin, 130021, China
| | - Jiashi Li
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
| | - Hefu Pu
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan, 030024, China
- School of Civil and Hydraulic Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
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Zheng X, Zhang B, Lai W, Wang M, Tao X, Zou M, Zhou J, Lu G. Application of bovine bone meal and oyster shell meal to heavy metals polluted soil: Vegetable safety and bacterial community. CHEMOSPHERE 2023; 313:137501. [PMID: 36502914 DOI: 10.1016/j.chemosphere.2022.137501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/25/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
The development of efficient, environmentally friendly soil amendments is necessary in order to minimize the risk of metal contaminants (Cd, Pb, Cu, and Zn) to the soil ecosystem. As soil amendments, bovine bone meal (BM) and oyster shell meal (OS) reduced the mobility and bioavailability of metals primarily by increasing soil pH. Soil geochemical properties (pH, EC, CEC, Ca, P, and K) after amendment supplementation were more likely to affect metal migration than enzyme activity. Furthermore, BM and OS were found to suppress the Cd and Pb uptake by water spinach, keeping them below international standards for safe utilization. The protein and sugar content and peroxidase (POD) activity showed a significant negative correlation with the amount of metal in water spinach, whereas superoxide dismutase (SOD), ascorbate peroxidase (APX) activities and malondialdehyde (MDA) content exhibited a positive correlation with metal content in water spinach. We also found that BM and OS had less perturbation to phylum-level and genus-level bacterial composition during the remediation of heavy metals contaminated soil. Based on the above, we assume that BM and OS are eco-friendly soil amendments, which could improve soil nutrients contents, stabilize heavy metals and regulate bacterial community structure. Our research contributes to resource utilization of waste and holds promise for widespread application in current agricultural systems.
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Affiliation(s)
- Xiongkai Zheng
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Bowen Zhang
- Guangzhou Urban Planning & Design Survey Research Institute, Guangzhou, 510060, China
| | - Weibin Lai
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Mengting Wang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, China
| | - Xueqin Tao
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China; Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control of Guangdong Higher Education Institutes, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
| | - Mengyao Zou
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China; Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control of Guangdong Higher Education Institutes, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jiangmin Zhou
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325035, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, China.
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Lei H, Xu X, Liu X, Park J, Yu Z, Liu H. Red Mud-Amended Soil as Highly Adsorptive Hybrid-Fill Materials for Controlling Heavy Metal Sewage Seepage in Industrial Zone. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:15043. [PMID: 36429762 PMCID: PMC9691102 DOI: 10.3390/ijerph192215043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
With the rapid development of urbanization, the problem of environmental pollution is becoming more and more serious. As a major pollutant, heavy metals have caused serious contamination in soil and groundwater. In order to prevent the diffusion of heavy metals in the soil from industrial sewage, the concept of hybrid-fill layer construction improved by red mud was proposed in this study. This study examines the adsorption capacities of lead and zinc ions and engineering characteristics on red mud-amended soils by direct shear, permeability, adsorption, desorption batch and column tests. Two mixing methods, full particle size displacement mixing and partial particle size displacement mixing, were adopted. The results showed that red mud effectively increased the adsorption capacity of soil to heavy metal ions, and the desorption rate of ions after adsorption was less than 3%, which had good anti-desorption ability. The optimum content of red mud in hybrid-fill material can be determined as 20%. The direct shear test showed that the internal friction angle of hybrid-fill material was 38.9°, and the cohesive force was 30.3 kPa, which met the engineering strength requirements of foundation materials. Based on the test results, red mud can be used as a barrier material to prevent heavy metal contamination in industrial sewage from diffusion, which controls not only heavy metal contamination but also consumes industrial by-products.
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Affiliation(s)
- Haomin Lei
- College of Construction Engineering, Jilin University, Changchun 130000, China
| | - Xin Xu
- College of Construction Engineering, Jilin University, Changchun 130000, China
| | - Xiaofeng Liu
- College of Civil Engineering, Taiyuan University of Technology, Taiyuan 030024, China
| | - Junboum Park
- Department of Civil and Environmental Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Zhongyu Yu
- College of Construction Engineering, Jilin University, Changchun 130000, China
| | - Hao Liu
- College of Construction Engineering, Jilin University, Changchun 130000, China
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The Dynamic Behaviour of a Binary Adsorbent in a Fixed Bed Column for the Removal of Pb2+ Ions from Contaminated Water Bodies. SUSTAINABILITY 2022. [DOI: 10.3390/su14137662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the search for a technically efficient and abundant adsorbent in water treatment processes, a bio-composite adsorbent derived from agricultural wastes has been identified as a potential candidate. In this study, eggshells and sugarcane bagasse were combined in varied proportions (1:0, 1:3, 1:1, 3:1 and 0:1) and applied as biosorbents in a lab-scale adsorption column. The effect of bed depth (4–12 cm) of the biosorbents was investigated which enabled the prediction of breakthrough curves for the removal of Pb (II) ions. The life span of the column was extended by increasing the bed depth of the column. The binary adsorbent of 1:3 weight ratio of <75 µm particle size showcased the highest removal efficiency of 91% at a bed depth of 12 cm. The mass transfer zone (MTZ) increased with increasing bed depth with a minor portion of the bed left unused, signifying that the process was highly efficient. The Thomas model constant, KTh, decreased with increasing bed depth with the maximum amount of Pb adsorbed being 28.27 mg/g. With the Yoon–Nelson model, KYN decreased with an increase in τ as the bed height increased. In this study, a novel approach was adopted where the proposed methodology enabled the use of a bio-composite adsorbent in heavy metal removal. The findings of this research will aid in the design and optimisation of the pilot-scale operation of environmentally friendly treatment options for metal laden effluent.
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Calugaru IL, Etteieb S, Magdouli S, Kaur Brar K. Efficiency of thermally activated eggshells for acid mine drainage treatment in cold climate. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2022; 57:81-91. [PMID: 35049418 DOI: 10.1080/10934529.2022.2027699] [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: 11/02/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
The selection process for a technology to treat the mine drainage is influenced by its performance, technical feasibility and cost. For the last decades, the mine industry has been searching for green methods to treat the acid mine drainage (AMD). This study evaluated thermally activated eggshells as a potential alternative for AMD treatment in cold climate. It was found that metal removal efficiency depended on the eggshells' calcination temperature and on the solid: liquid ratio. Eggshells calcined at 900 °C and employed in a solid: liquid ratio of 0.3% increased the pH of a mine effluent from 2.5 to 6.9 at 20 °C and to 9.2 at 4 °C, respectively. Heavy metal concentrations were reduced as follows: As <0.0005 mg/L, Cd 0.00022 and 0.00009 mg/L, Cu 0.0061 and 0.0091 mg/L, Co 0.0338 and 0.0016 mg/L, Cr 0.0015 and 0.0022 mg/L, Fe <0.01 mg/L, Ni 0.0291 and 0.0024 mg/L, Mo <0.0005 mg/L, Se 0.0033 and 0.0044 mg/L, and Zn 0.007 and 0.022 mg/L, at 20 °C and 4 °C, respectively. Consequently, the treated mine effluent satisfied both the Quebec and Canadian regulations. Based on these results, thermally activated eggshells could be efficiently employed for the active and passive treatment of AMD in a cold climate.
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Affiliation(s)
| | - Selma Etteieb
- Centre technologique des résidus industriels, Rouyn-Noranda, Québec, Canada
| | - Sara Magdouli
- Centre technologique des résidus industriels, Rouyn-Noranda, Québec, Canada
- Department of Civil Engineering, Lassonde School of Engineering, York University, Toronto, Ontario, Canada
| | - Kamalpreet Kaur Brar
- Centre technologique des résidus industriels, Rouyn-Noranda, Québec, Canada
- Department of Civil Engineering, Lassonde School of Engineering, York University, Toronto, Ontario, Canada
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Fseha YH, Sizirici B, Yildiz I, Yavuz C. Pristine biochar performance investigation to remove metals in primary and secondary treated municipal wastewater for groundwater recharge application. PLoS One 2022; 17:e0278315. [PMID: 36472965 PMCID: PMC9725145 DOI: 10.1371/journal.pone.0278315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
In this study, pristine biochar derived from date palm at 500°C was used in batch reactors (simulating blending adsorbent in aeration tank) and fixed-bed columns (simulating holding adsorbent in fixed-bed reactors). The removal performance of the biochar was assessed toward single and mixed-metal solutions as well as synthetic primary and secondary treated wastewater for copper (Cu2+), iron (Fe2+), nickel (Ni2+) and zinc (Zn2+). The order of maximum adsorption capacities of the metal ions at pH 7 followed: Fe2+ (2.92/2.94 mg/g)>Cu2+(2.69/2.78 mg/g) >Zn2+(2.03/2.19 mg/g)>Ni2+(1.69/1.02 mg/g) in single/mixed-metal solutions and Zn2+(2.91/11.26 mg/g)>Fe2+(0.60/5.29 mg/g)>Cu2+(0.56/5.05 mg/g)>Ni2+(0.13/2.02 mg/g) in synthetic primary/secondary treated wastewater. Blending biochar in aeration tank reduced metal concentrations. The metal ion concentrations in the final effluent were below the World Health Organization drinking water limits (2, 0.3, 0.1 and 3 mg/L for Cu2+, Fe2+, Ni2+ and Zn2+, respectively) suggesting that treated secondary wastewater can be spread into potable aquifers following disinfection. The Freundlich and the Pseudo-second order models fit best the batch experimental data. Experimental data from column analysis fit well to the Thomas model. The adsorption of metal ions on the surface of biochar was confirmed by Scanning electron microscopy, Energy dispersive X-ray studies, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Desorption studies using different eluents demonstrated the reusability potential of the studied biochar.
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Affiliation(s)
- Yohanna Haile Fseha
- Department of Civil Infrastructure and Environmental Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
- * E-mail:
| | - Banu Sizirici
- Department of Civil Infrastructure and Environmental Engineering, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Ibrahim Yildiz
- Department of Chemistry, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Cafer Yavuz
- Advanced Membranes and Porous Materials Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
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Jaradat AQ, Telfah DB, Ismail R. Heavy metals removal from landfill leachate by coagulation/flocculation process combined with continuous adsorption using eggshell waste materials. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:3817-3832. [PMID: 34928846 DOI: 10.2166/wst.2021.493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The use of agricultural waste materials to remove heavy metals from wastewater is attractive due to its simplicity and economic efficiency. In this study, the applicability of calcined eggshell waste materials (CES) for heavy metals removal from real wastewater were examined via transport column experiment preceded by coagulation/flocculation process.A column packed with granular activated carbon (GAC) is operated in parallel to CES column to evaluate the adsorptive attributes of CES. The findings are assessed from another set of column experiments consisting of sand followed by CES column to evaluate the effect of particulate matter (PM) on CES performance toward heavy metals removal. In coagulation experiment, alum addition at an optimum dose (3.0 g/L) reduced the total suspended solids (TSS) by 80%, whereas the Fe, Pb, Zn, Cu, Ni, and Cr were reduced by 80%, 77%, 76%, 73%, 56%, and 49%, respectively. Under the current applied hydrodynamic conditions, using sand column before CES column improved the removal efficiencies of Fe, Pb, Cu, Zn, Ni, and Cr from 50% to 92%, 55% to 93%, 60% to 87%, 53% to 76%, 45% to 65%, and 41% to 60%, respectively. The whole results illustrate that CES can be competitive to GAC for heavy metals removal from landfill leachate, mainly if applied after PM removal by sand filtration.
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Affiliation(s)
- A Q Jaradat
- Department of Civil Engineering, Yarmouk University, Irbid, Jordan E-mail:
| | - Dua'a B Telfah
- Department of Civil Engineering, Yarmouk University, Irbid, Jordan E-mail:
| | - Rabah Ismail
- Department of Civil Engineering, Jadara University, Irbid, Jordan
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Ahmadpour N, Sayadi MH, Sobhani S, Hajiani M. Photocatalytic degradation of model pharmaceutical pollutant by novel magnetic TiO 2@ZnFe 2O 4/Pd nanocomposite with enhanced photocatalytic activity and stability under solar light irradiation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 271:110964. [PMID: 32778273 DOI: 10.1016/j.jenvman.2020.110964] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 06/05/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
In the last decades, the use of magnetic nanocomposites as a catalyst was considered for removal of organic pollutants due to its easy separation. Therefore, initially, TiO2@ZnFe2O4/Pd nanocomposite was prepared and then used in the photodegradation of diclofenac under direct solar irradiation in the batch and continuous systems. The structure, morphology and other specifications of produced nanocatalyst were determined via XRD, VSM, FESEM/EDX, FTIR, GTA, UV-Vis, Zeta potential, XPS and ICP-OES. The effective factors on diclofenac removal via nanophotocatalyst viz. pH, catalyst concentration, initial concentration of diclofenac, and flow rate and column length on diclofenac photodegradation were studied. Based on the results, the optimal rate for pH, catalyst concentration, and initial concentration of diclofenac was 4, 0.03 g/l and 10 mg/l respectively. Pd-coated TiO2@ZnFe2O4 magnetic photocatalyst had higher photocatalytic activity in diclofenac photodegradation in relation to ZnFe2O4 and TiO2@ZnFe2O4 under solar light irradiation. The findings showed that after five recycles, the photocatalytic efficiency did not show much reduction i.e. the removal efficiency from 86.1% in the first cycle reduced only to 71.38% in the last cycle. Likewise, in this study, with flow rate reduction and column length increase diclofenac degradation rate increased.
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Affiliation(s)
- Najmeh Ahmadpour
- Department of Environmental Engineering, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran
| | - Mohammad Hossein Sayadi
- Department of Environmental Engineering, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran.
| | - Sara Sobhani
- Department of Chemistry, College of Sciences, University of Birjand, Birjand, Iran
| | - Mahmood Hajiani
- Department of Environmental Engineering, Faculty of Natural Resources and Environment, University of Birjand, Birjand, Iran
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Abstract
This study investigates the impact of eggshell particle size and solid-to-water (s/w) ratio on lead (Pb2+) removal from aqueous solution. Collected raw eggshells were washed, crushed, and sieved into two particle sizes (<150 and 150–500 µm). Batch Pb2+ removal experiments were conducted at different s/w ratios with initial Pb2+ concentrations of up to 70 mg/L. The contribution of precipitation to Pb2+ removal was simulated by quantifying removal using eggshell water, whereas sorbed Pb2+ was quantified by acid digestion. Results indicated that eggshell particle sizes did not affect Pb2+ removal. High removal (up to 99%) of Pb2+ was achieved for low initial Pb2+ concentrations (<30 mg/L) across all s/w ratios studied. However, higher removal capacity was observed at lower s/w ratios. In addition, results confirmed that precipitation played a major role in the removal of Pb2+ by eggshells. Yet, this role decreased as the s/w ratio and initial concentration of Pb2+ increased. A predictive relationship that relates the normalized removal capacity of eggshells to the s/w ratio was developed to potentially facilitate the design of the reactor.
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Karoshi G, Kolar P, Shah SB, Gilleskie G. Recycled eggshells as precursors for iron-impregnated calcium oxide catalysts for partial oxidation of methane. BIORESOUR BIOPROCESS 2020. [DOI: 10.1186/s40643-020-00336-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractThere is a significant interest in converting eggshells into value-added products. Therefore, the goal of this research is to synthesize and study iron-impregnated eggshells as a catalyst for partial oxidation of methane. The objectives of this research were to test the effects of iron loading, flow rate, oxygen concentration, and temperature on methane oxidation. The catalysts were synthesized using ferric chloride hexahydrate at various loadings and tested in a heated stainless-steel reactor under different experimental conditions. The reaction products included C2–C7 hydrocarbons, carbon monoxide, and carbon dioxide depending on the reaction conditions. Results indicated that iron loading beyond 5 wt% caused a decrease in methane conversion. A decrease in oxygen concentration enhanced methane conversion with a substantial drop in the production of CO2. Besides, an increase in temperature resulted in a decrease in methane conversion with a simultaneous increase in the production of CO2 via overoxidation. The reusability experiments indicated that the catalyst was active for four reaction cycles. Our results indicate that eggshells can be used as catalyst support for methane partial oxidation and can simultaneously solve the waste disposal problems faced by the poultry industry.
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Rahmani-Sani A, Singh P, Raizada P, Claudio Lima E, Anastopoulos I, Giannakoudakis DA, Sivamani S, Dontsova TA, Hosseini-Bandegharaei A. Use of chicken feather and eggshell to synthesize a novel magnetized activated carbon for sorption of heavy metal ions. BIORESOURCE TECHNOLOGY 2020; 297:122452. [PMID: 31787507 DOI: 10.1016/j.biortech.2019.122452] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/16/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
Keeping environment and sustainability concept in view with preparation of new sorbents, two waste by-products from the poultry industry, i.e. feather and eggshell, were used for synthesis of a new magnetic activated carbon for sorption of heavy metal ions. Using response surface methodology based central composite design (RSM-CCD) technique, chicken feather and acid-digested eggshell were used as precursor and activation material, respectively, for the synthesis of the herein studied activated carbon (eggshell activated chicken feather carbon; ESCFC). The prepared activated carbon was magnetized for easy separation from water media, and iron oxide magnetized ESCFC (IOM-ESCFC) was comprehensively examined for removing some heavy metallic ions (Pb2+, Cd2+, Cu2+, Zn2+, and Ni2+) from water. The maximum mono-layer sorption capacities and the highness of sorption speed, along with thermodynamic studies, demonstrated that IOM-ESCFC can be regarded as a potential adsorbent against heavy metal ions from waters and wastewaters.
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Affiliation(s)
- Abolfazl Rahmani-Sani
- Department of Environmental health Engineering, Faculty of Health, Sabzevar University of Medical Sciences, Sabzevar, Iran
| | - Pardeep Singh
- School of Chemistry, Faculty of Basic Sciences, Shoolini University, Solan Himachal Pradesh 173212, India
| | - Pankaj Raizada
- School of Chemistry, Faculty of Basic Sciences, Shoolini University, Solan Himachal Pradesh 173212, India
| | - Eder Claudio Lima
- Institute of Chemistry, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonc¸ alves 9500, Postal Box 15003, 91501-970 Porto Alegre, RS, Brazil
| | - Ioannis Anastopoulos
- Department of Chemistry, University of Cyprus, P.O. Box 20537, CY-1678 Nicosia, Cyprus
| | - Dimitrios A Giannakoudakis
- Laboratory of General & Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR 54124, Greece
| | - Selvaraju Sivamani
- Chemical and Petrochemical Engineering Section, Engineering Department, Salalah College of Technology, Oman
| | - Tetiana A Dontsova
- Department of Inorganic Substances, Water Purification, and General Chemical Technology, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Kyiv 03056, Ukraine
| | - Ahmad Hosseini-Bandegharaei
- Department of Environmental health Engineering, Faculty of Health, Sabzevar University of Medical Sciences, Sabzevar, Iran; Department of Engineering, Kashmar Branch, Islamic Azad University, PO Box 161, Kashmar, Iran.
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Yan Y, Yang S, Jiang F, Luo Y, Gao H, Liao Y. Efficient removal of lead ions from aqueous solutions using ZnSe/ZnO/Bio-CaCO 3. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2020; 81:91-101. [PMID: 32293592 DOI: 10.2166/wst.2020.081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The sheet-like adsorbent of the eggshell wastes was prepared by the thermal hydrolysis method. The structure of the adsorbent was characterized by scanning electron microscope, Brunauer-Emmett-Teller, X-ray diffraction, transmission electron microscope, and X-ray photoelectron spectrometer. The adsorption capacity was investigated in a Pb2+ solution. The effects of initial pH, salt concentration, contact time, and adsorbate concentration on the adsorption of lead ions were investigated in detail. The morphology of the adsorbent was sheet-like microspheres. Zinc selenide/zinc oxide could be uniformly loaded onto the eggshell waste surface, which could effectively enhance the specific surface area of the eggshell wastes. The adsorption kinetics and isotherm followed the pseudo-second-order and Langmuir-Freundlich isotherm model, respectively. The synthesized adsorbent showed a maximum lead adsorption capacity of 1,428.78 mg/g at room temperature. Ion-exchange was the main adsorption mechanism.
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Affiliation(s)
- Yi Yan
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail: ; †Yi Yan and Shuai Yang contributed equally to this work
| | - Shuai Yang
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail: ; †Yi Yan and Shuai Yang contributed equally to this work
| | - Feng Jiang
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail:
| | - Yuwei Luo
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail:
| | - Hejun Gao
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail: ; Institute of Applied Chemistry, China West Normal University, Nanchong 637000, China
| | - Yunwen Liao
- College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000, China E-mail:
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14
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Wei Y, Salih KAM, Lu S, Hamza MF, Fujita T, Vincent T, Guibal E. Amidoxime Functionalization of Algal/Polyethyleneimine Beads for the Sorption of Sr(II) from Aqueous Solutions. Molecules 2019; 24:E3893. [PMID: 31671819 PMCID: PMC6864727 DOI: 10.3390/molecules24213893] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/22/2019] [Accepted: 10/26/2019] [Indexed: 01/26/2023] Open
Abstract
There is a need for developing new sorbents that incorporate renewable resources for the treatment of metal-containing solutions. Algal-polyethyleneimine beads (APEI) (reinforced with alginate) are functionalized by grafting amidoxime groups (AO-APEI). Physicochemical characteristics of the new material are characterized using FTIR, XPS, TGA, SEM, SEM-EDX, and BET. AO-APEI beads are tested for the recovery of Sr(II) from synthetic solutions after pH optimization (≈ pH 6). Uptake kinetics is fast (equilibrium ≈ 60-90 min). Sorption isotherm (fitted by the Langmuir equation) shows remarkable sorption capacity (≈ 189 mg Sr g-1). Sr(II) is desorbed using 0.2 M HCl/0.5 M CaCl2 solution; sorbent recycling over five cycles shows high stability in terms of sorption/desorption performances. The presence of competitor cations is studied in relation to the pH; the selectivity for Sr(II) is correlated to the softness parameter. Finally, the recovery of Sr(II) is carried out in complex solutions (seawater samples): AO-APEI is remarkably selective over highly concentrated metal cations such as Na(I), K(I), Mg(II), and Ca(II), with weaker selectivity over B(I) and As(V). AO-APEI appears to be a promising material for selective recovery of strontium from complex solutions (including seawater).
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Affiliation(s)
- Yuezhou Wei
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
| | - Khalid A M Salih
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
| | - Siming Lu
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
| | - Mohammed F Hamza
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
- Nuclear Materials Authority, POB 530, El-Maadi, Cairo, Egypt.
- C2MA, IMT-Mines Ales, Univ. Montpellier, F-30319 Alès cedex, France.
| | - Toyohisa Fujita
- Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
| | - Thierry Vincent
- C2MA, IMT-Mines Ales, Univ. Montpellier, F-30319 Alès cedex, France.
| | - Eric Guibal
- C2MA, IMT-Mines Ales, Univ. Montpellier, F-30319 Alès cedex, France.
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15
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Van HT, Nguyen LH, Nguyen VD, Nguyen XH, Nguyen TH, Nguyen TV, Vigneswaran S, Rinklebe J, Tran HN. Characteristics and mechanisms of cadmium adsorption onto biogenic aragonite shells-derived biosorbent: Batch and column studies. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 241:535-548. [PMID: 30318157 DOI: 10.1016/j.jenvman.2018.09.079] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 09/09/2018] [Accepted: 09/22/2018] [Indexed: 06/08/2023]
Abstract
Calcium carbonate (CaCO3)-enriched biomaterial derived from freshwater mussel shells (FMS) was used as a non-porous biosorbent to explore the characteristics and mechanisms of cadmium adsorption in aqueous solution. The adsorption mechanism was proposed by comparing the FMS properties before and after adsorption alongside various adsorption studies. The FMS biosorbent was characterized using nitrogen adsorption/desorption isotherm, X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, Fourier-transform infrared spectroscopy, and point of zero charge. The results of batch experiments indicated that FMS possessed an excellent affinity to Cd(II) ions within solutions pH higher than 4.0. An increase in ionic strength resulted in a significant decrease in the amount of Cd(II) adsorbed onto FMS. Kinetic study demonstrated that the adsorption process quickly reached equilibrium at approximately 60 min. The FMS biosorbent exhibited the Langmuir maximum adsorption capacity as follows: 18.2 mg/g at 10 °C < 26.0 mg/g at 30 °C < 28.6 mg/g at 50 °C. The Cd(II) adsorption process was irreversible, spontaneous (-ΔG°), endothermic (+ΔH°), and more random (+ΔS°). Selective order (mmol/g) of metal cations followed as Pb2+ > Cd2+ > Cu2+ > Cr3+ > Zn2+. For column experiments, the highest Thomas adsorption capacity (7.86 mg/g) was achieved at a flow rate (9 mL/min), initial Cd(II) concentration (10 mg/L), and bed height (5 cm). The Cd(II) removal by FMS was regarded as non-activated chemisorption that occurred very rapidly (even at a low temperature) with a low magnitude of activation energy. Primary adsorption mechanism was surface precipitation. Cadmium precipitated in the primary (Cd,Ca)CO3 form with a calcite-type structure on the FMS surface. A crust of rhombohedral crystals on the substrate was observed by SEM. Freshwater mussel shells have the potential as a renewable adsorbent to remove cadmium from water.
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Affiliation(s)
- Huu Tap Van
- Faculty of Natural Resources and Environment, Thai Nguyen University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Vietnam
| | - Lan Huong Nguyen
- Faculty of Environment, Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry (HUFI), 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, Ho Chi Minh City, Vietnam
| | - Van Dang Nguyen
- Faculty of Physic and Technology, Thai Nguyen University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Vietnam
| | - Xuan Hoan Nguyen
- Faculty of Environment, Natural Resources and Climate Change, Ho Chi Minh City University of Food Industry (HUFI), 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, Ho Chi Minh City, Vietnam
| | - Thanh Hai Nguyen
- Faculty of Environment, Thai Nguyen University of Agriculture and Forestry (TUAF), Thai Nguyen City, Vietnam
| | - Tien Vinh Nguyen
- Faculty of Engineering and IT, University of Technology, Sydney (UTS), Sydney, Australia
| | | | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste-Management, Laboratory of Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, Seoul 05006, South Korea
| | - Hai Nguyen Tran
- Sustainable Management of Natural Resources and Environment Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Vietnam.
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16
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Selective Mineralization and Recovery of Au(III) from Multi-Ionic Aqueous Systems by Bacillus licheniformis FZUL-63. MINERALS 2019. [DOI: 10.3390/min9070392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The recovery of precious metals is a project with both economic and environmental significance. In this paper, how to use bacterial mineralization to selectively recover gold from multi-ionic aqueous systems is presented. The Bacillus licheniformis FZUL-63, isolated from a landscape lake in Fuzhou University, was shown to selectively mineralize and precipitate gold from coexisting ions in aqueous solution. The removal of Au(III) almost happened in the first hour. Scanning electron microscope with X-ray energy dispersive spectroscopy (SEM/EDS-mapping) results and fourier transform infrared spectroscopy (FTIR) data show that the amino, carboxyl, and phosphate groups on the surface of the bacteria are related to the adsorption of gold ions. X-ray photoelectron spectroscopy (XPS) results implied that Au(III) ions were reduced to those that were monovalent, and the Au(I) was then adsorbed on the bacterial surface at the beginning stage (in the first hour). X-ray diffraction (XRD) results showed that the gold biomineralization began about 10 h after the interaction between Au(III) ions and bacteria. Au(III) mineralization has rarely been influenced by other co-existing metal ions. Transmission electron microscope (TEM) analysis shows that the gold nanoparticles have a polyhedral structure with a particle size of ~20 nm. The Bacillus licheniformis FZUL-63 could selectively mineralize and recover 478 mg/g (dry biomass) gold from aqua regia-based metal wastewater through four cycles. This could be of great potential in practical applications.
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17
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Xia Y, Huang X, Li W, Zhang Y, Li Z. Facile defluoridation of drinking water by forming shell@fluorapatite nanoarray during boiling egg shell. JOURNAL OF HAZARDOUS MATERIALS 2019; 361:321-328. [PMID: 30245254 DOI: 10.1016/j.jhazmat.2018.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
High fluoride water is one of the major problems against drinking water and are affecting millions of people all over the world. Refined adsorbents and water treatment plants aim at massive water supply but can't meet scattered household requirements, especially in the developing areas. Here, we developed a facile defluoridation method in which F- can be removed by boiling eggs or shell assisted by phosphate. 0.4 L of high fluoride water (10 mg/L) can be transformed to safe drinking water with F- concentration lower than 1.5 mg/L by boiling one egg at 80 °C for 10 min with the addition of 0.3 g/L of NaH2PO4 and 0.05 v% acetic acid. The mechanism study shows that F- is adsorbed onto the egg shell outer surface forming nanorod arrays of fluorapatite and/or F- substituted hydroxyapatite. Higher F- adsorption capacity can be obtained (Langmuir adsorption capacity, 47.9 mg/g) if using egg shell powder instead of whole eggs. Pilot scale defluoridation (2.5 L, 10 times) was successfully realized by boiling egg shell in the presence of phosphate and acetic acid. The boiling shell defluoridation technology has potential household applications by common people with little professional backgrounds.
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Affiliation(s)
- Yan Xia
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Xuanqi Huang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Wanbin Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Yuanwei Zhang
- Department of Chemistry and Environmental Science, College of Science and Liberal Arts, New Jersey Institute of Technology, 323 Martin Luther King, Jr. Blvd., Newark, NJ, 07102, USA
| | - Zhanjun Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
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18
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Fernández-González R, Martín-Lara MA, Iáñez-Rodríguez I, Calero M. Removal of heavy metals from acid mining effluents by hydrolyzed olive cake. BIORESOURCE TECHNOLOGY 2018; 268:169-175. [PMID: 30077173 DOI: 10.1016/j.biortech.2018.07.124] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 06/08/2023]
Abstract
The present study aims to solve two major challenges of the current society. On the one hand, it investigated the heavy metal removal from mining wastewater. On the other hand, it proposed an alternative use for olive cake. Firstly, a physic-chemical characterization of real wastewater and hydrolyzed olive cake was carried out. Secondly, a study of the affinity of the material for the different metals (chromium, manganese, copper, zinc, nickel and lead) was performed. The hydrolyzed olive cake showed a low content in ash (3.08%) and in water-soluble compounds (2.80%). The material presented the highest retention capacity for the lead (41.54 mg/g) and the lowest for the manganese (3.57 mg/g). After that, biosorption experiments in fixed-bed column were carried out using mining real water. In order to improve the biosorption capacity, the water pH was raised up to 6. The results were quite satisfactory with respect to others similar studies.
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Affiliation(s)
- R Fernández-González
- Department of Chemical Engineering, Faculty of Sciences, University of Granada. Avda. Fuentenueva, s/n 18071, Granada, Spain
| | - M A Martín-Lara
- Department of Chemical Engineering, Faculty of Sciences, University of Granada. Avda. Fuentenueva, s/n 18071, Granada, Spain
| | - I Iáñez-Rodríguez
- Department of Chemical Engineering, Faculty of Sciences, University of Granada. Avda. Fuentenueva, s/n 18071, Granada, Spain
| | - M Calero
- Department of Chemical Engineering, Faculty of Sciences, University of Granada. Avda. Fuentenueva, s/n 18071, Granada, Spain.
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19
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Oladipo AS, Ajayi OA, Oladipo AA, Azarmi SL, Nurudeen Y, Atta AY, Ogunyemi SS. Magnetic recyclable eggshell-based mesoporous catalyst for biodiesel production from crude neem oil: Process optimization by central composite design and artificial neural network. CR CHIM 2018. [DOI: 10.1016/j.crci.2018.03.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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20
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Filho CMC, Bueno PVA, Matsushita AFY, Rubira AF, Muniz EC, Durães L, Murtinho DMB, Valente AJM. Synthesis, characterization and sorption studies of aromatic compounds by hydrogels of chitosan blended with β-cyclodextrin- and PVA-functionalized pectin. RSC Adv 2018; 8:14609-14622. [PMID: 35540733 PMCID: PMC9079937 DOI: 10.1039/c8ra02332h] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 04/11/2018] [Indexed: 11/21/2022] Open
Abstract
Complex coacervation of chitosan with β-cyclodextrin- and poly(vinyl alcohol)-functionalized pectin: ability for simultaneous removal of six different aromatic compounds.
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Affiliation(s)
- Cesar M. C. Filho
- CQC
- Department of Chemistry
- University of Coimbra
- 3004-535 Coimbra
- Portugal
| | - Pedro V. A. Bueno
- Grupo de Materiais Poliméricos e Compósitos (GMPC) – Departamento de Química
- Universidade Estadual de Maringá
- UEM
- Maringá
- Brazil
| | | | - Adley F. Rubira
- Grupo de Materiais Poliméricos e Compósitos (GMPC) – Departamento de Química
- Universidade Estadual de Maringá
- UEM
- Maringá
- Brazil
| | - Edvani C. Muniz
- Grupo de Materiais Poliméricos e Compósitos (GMPC) – Departamento de Química
- Universidade Estadual de Maringá
- UEM
- Maringá
- Brazil
| | - Luísa Durães
- CIEPQPF
- Department of Chemical Engineering
- University of Coimbra
- 3030-790 Coimbra
- Portugal
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Adsorption of Cd (II) on Modified Granular Activated Carbons: Isotherm and Column Study. Molecules 2017; 22:molecules22122280. [PMID: 29261156 PMCID: PMC6149846 DOI: 10.3390/molecules22122280] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 11/26/2022] Open
Abstract
In this work, equilibrium and dynamic adsorption tests of cadmium Cd (II) on activated carbons derived from different oxidation treatments (with either HNO3, H2O2, or NaOCl, corresponding to GACoxN, GACoxP, and GACoxCl samples) are presented. The oxidation treatments determined an increase in the surface functional groups (mainly the acidic ones) and a decrease in the pHPZC (except for the GACoxCl sample). A slight alteration of the textural parameters was also observed, which was more significant for the GACoxCl sample, in terms of a decrease of both Brunauer-Emmett-Teller (BET) surface area and micropore volume. Adsorption isotherms were determined for all the adsorbents and a significant increase in the adsorption performances of the oxidized samples with respect to the parent material was observed. The performances ranking was GACoxCl > GACoxP > GACoxN > GAC, likely due to the chemical surface properties of the adsorbents. Dynamic tests in a fixed bed column were carried out in terms of breakthrough curves at constant Cd inlet concentration and flow rate. GACoxCl and GACoxN showed a significantly higher value of the breakpoint time, likely due to the higher adsorption capacity. Finally, the dynamic tests were analyzed in light of a kinetic model. In the adopted experimental conditions, the results showed that mass transfer is controlled by internal pore diffusion, in which surface diffusion plays a major role.
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