Review on Adsorption of Heavy Metal in Wastewater by Using Geopolymer (original) (raw)
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Geopolymer as an adsorbent of heavy metal: A review
This paper reviews about geopolymer based adsorbent focusing in the removal of heavy metal. The reviews include fundamental and types of material used in the formation of adsorbents. Geopolymer based adsorbent got attention recently due to its unique three-dimensional network structure, with fixed size pores and paths that allow certain heavy metal to pass through. Most materials that applied as adsorbent such as fly ash, metakaolin, kaolin and dolomite. A lot of sludge nowadays only dumped in the landfill which can be used as one of new materials as geopolymer based adsorbent.
A review on geopolymers as emerging materials for the adsorption of heavy metals and dyes
Journal of environmental management, 2018
The world water resources are contaminated due to discharge of a large number of pollutants from industrial and domestic sources. A variety of a single and multiple units of physical, chemical, and biological processes are employed for pollutants removal from wastewater. Adsorption is the most widely utilized process due to high efficiency, simple procedure and cost effectiveness. This paper reviews the research work carried out on the use of geopolymer materials for the adsorption of heavy metals and dyes. Geopolymers possess good surface properties, heterogeneous microstructure and amorphous structure. The performance of geopolymers in the removal of heavy metals and dyes is reported comparable to other materials. The pseudo-second order kinetics and Langmuir isotherm models mostly fit to the adsorption data suggesting homogeneous distribution of adsorption sites with the formation of monolayer adsorbate on the surface of geopolymers. Adsorption of heavy metals and dyes onto geopo...
2020
This paper investigates the immobilization behaviors of Cd2+, Pb2+ and Hg2+ ions in a geopolymer based on water treatment sludge (WTS) and dealuminated metakaolin (DaMK) solid waste from alum industry. For synthesis of WTS/DaMK based geopolymer, five mixes of WTS/DaMK (75/25, 80/20, 85/15, 90/10 and 95/5, respectively) are tested to obtain the optimum synthesis condition based on the compressive strength. Results showed that the geopolymer mortar with 85/15WTS/DaMK has the highest compressive strength (8 MPa). In addition, X-ray Diffraction (XRD) and X-ray Fluorescence (XRF) techniques are used to characterize the mineral and chemical compositions of WTS and DaMK. WTS/DaMK based geopolymer mortar have been tested for leaching to study its immobilization behavior under the optimum condition. The Cd2+, Pb2+ and Hg2+ ions were used and effectively immobilized in this study. The heavy metals with concentrations of 100, 200 and 300 ppm were used in the geopolymer matrix giving about 98% ...
Adsorption of Cadmium Ions on Geopolymers Derived from Ordinary Clay and Rice Husk Ash
2018
The presence of heavy metals in water is of growing concern. One crucial global strain is the existing disparity in water distribution resulting into millions of people lacking access to safe clean water. This is exasperated by the looming climate change and increased pollution impendence posed by industrialization and population growth. Consequently, pursuance of sustainable materials and technologies for wastewater remediation is critical. Adoption of adsorbents for water treatment is desirable due to their simplicity and cheap materials involved. Geopolymers are prepared hydrothermally using alumina and silica gleaned from clay and rice husks waste materials respectively. These materials are locally attainable and environmentally benign. This work reports synthesis of geopolymers GP-1, GP-2 and GP-3 prepared using clays from three different regions. The XRD diffraction patterns obtained revealed the presence of quartz (SiO2), albite (NaAlSi3O8), vermiculite (Mg,Fe,Al)3((Al,Si)4O1...
Brazilian Journal of Experimental Design, Data Analysis and Inferential Statistics, 2021
Due to several catastrophic fires in France involving flammable organic plastics, Davidovits began his search for new materials resistant to heat, developing an alkaline activated silico-aluminous material, which was called a geopolymer. The polymeric Si-O-Al network gives the geopolymer ion exchange property, allowing the immobilization of heavy and radioactive metals within the material matrix. Due to the geopolymer's characteristic of immobilizing heavy metals in its matrix, this project aims to evaluate the geopolymer's ability to absorb heavy metals in contaminated water. For this, samples of porous geopolymers with magnetic charges in concentrations of 1, 2 and 3% were produced. And, subsequently, toxic metal solutions were made, such as Chromium, Cadmium and Lead at a concentration of 3ppm, then the sorption was carried out using the static method, where 0.5 g of the gepopolymer was dispersed in 25 ml of contaminated water and left stirring for 5 minutes, with the aid of a mechanical stirrer, and left to rest for 24 hours for the geopolymer to settle and the supernatant to be collected (this procedure was performed for geopolymers with and without magnetic charges). Afterwards, the treated water was analyzed by the atomic absorption technique, in order to investigate the geopolymer's sorption capacity. All tests were performed in triplicate and the mean, standard deviation and 95% confidence limit were evaluated to determine the reliability of the results.
Inorganic polymers (geopolymers) were synthesized by alkali activation of water treatment residue, a waste material containing aluminosilicates and a significant concentration of iron in the form of a ferric nanoparticle oxide gel. The effect on the structures of these geopolymers of incorporating the heavy metals chromium, zinc and iron, as occur in industrial wastewaters, was studied by their addition at the geopolymer synthesis stage, both as the pre-prepared hydroxides and as 1 M nitrate solutions. The heavy metals form several new crystalline phases, but the geopolymers display typical solid-state 27 Al and 29 Si MAS NMR characteristics. The 28-day strengths of the geopolymers without the metals (up to 11.2 MPa) were significantly degraded by the presence of the heavy metals, particularly 1 M zinc nitrate solution. The deleterious effect of the heavy metals on the strength may arise from their presence as the hydroxides rather than their incorporation as charge-balancing cations in the geopolymer structure. Leaching tests in simulated acid rain indicate that the geopolymers with molar ratios of SiO 2 /Al 2 O 3 = 1.78 are capable of immobilizing all three metals to within safe leachate levels. The geopolymers are sufficiently strong to withstand handling and transportation and are capable of immobilizing wastes containing these heavy metals for storage or disposal.
Kaolin-Based Geopolymer as a Heavy Metal Removal: Short Review
European Journal of Materials Science and Engineering
Adsorption procedure have been studies and found to be an effective, easy, and low-cost approach for removing heavy metals from aqueous solution when compared to other methods and technologies. Porous geopolymer will be made by combining aluminosilicate mineral with an alkaline activation solution to be utilized as an adsorbent. This review focuses on the current development in heavy metal removal material. This work also summarize the crucial factors (such as solid-to-liquid ratio, foaming agent ratio, sintering temperatures, and adsorbent dosage) influenced the properties (pore formation, microstructure, chemical bonding, and phase analysis) of kaolin-based geopolymer were highlighted. This review manifests the remarkable potential of kaolin-based geopolymer in high-added value applications.
Structure–Property Relationship of Geopolymers for Aqueous Pb Removal
ACS Omega
The geopolymeran inorganic polymeric material synthesized from the reaction of aluminosilicate precursors and alkaline activating solutionshas gained wide research attention in recent decades as a promising adsorbent for the removal of aqueous heavy metals. However, the high variability of the material and several unanswered questions have limited its development and general adoption in the industry. This study evaluates the impacts of composition and microstructure on the performance of geopolymers for aqueous lead (Pb) removal to elucidate the composition−structure− property relationship. The Pb sorption kinetics and efficiency of four geopolymers, prepared using different fly ash precursors and activating solutions, were investigated. Although all the four geopolymer compositions studied displayed a high Pb removal efficiency of over 99.5%, with a slight decrease in efficiency with increasing Ca/(Si + Al) and Al/Si contents, the results show that the sorption kinetics decreases exponentially with increasing Ca/(Si + Al) and Al/Si molar ratios. The performance of the geopolymers also shows strong correlation to the microstructure, wherein the sorption kinetics increases exponentially, while the efficiency increases slightly, with increasing mass fraction of the amorphous phase in the geopolymer's phase assemblage. The results of this research indicate that using appropriate precursor formulation and curing conditions to evoke the best microstructures, geopolymer materials can be optimized for high performance in removing heavy metals, thereby improving the chances of the material's general acceptability in the adsorbent industry.
Zenodo (CERN European Organization for Nuclear Research), 2019
Geopolymers are the synthetic analogues of natural zeolitic materials which are aluminosilicate materials. They can be used in the immobilization of heavy metal contaminants as well as in the structural products. Thus, the aim of this research work is to study the use of kaolinite and fly ash-based geopolymer to immobilize heavy and toxic metals in application of the removal of toxic metals from contaminated wastewater and the extraction of heavy metals from their leached solutions. The characterization of kaolinite samples from Taungnauk and Kyauktaga and fly ash samples from industries located at Tigyit and Pyin Oo Lwin were carried out by using EDXRF, SEM, XRD, FTIR and TG-DTA instrumental techniques. Moreover, the chemical compositions of the samples were also analyzed by using standard conventional methods. The geopolymer materials were prepared by using different ratios of kaolinite and fly ash with different concentrations of sodium hydroxide at room temperature. These geopolymer samples were analyzed and characterized by conventional methods and modern instrumental techniques such as EDXRF, SEM, XRD, FTIR and TG-DTA. Moreover, some mechanical properties of the prepared geopolymers, such as compressive strength and tensile strength were also carried out. Since this research work concerns with the use of geopolymers for immobilization of heavy and toxic metals, the removal of toxic metal ions in wastewater samples from different industries by using prepared geopolymer samples (H1-H4). Among the four geopolymer samples, geopolymer sample (H1) was found to be the maximum leaching property (i.e., the immobilization efficiency exceeds 92.9% when Pb 2+ ions contained in metal loaded geopolymer (H1). Moreover, the removal percents of Pb 2+ , Cd 2+ and As 3+ ions from wastewater samples were found to be in the range of 67.5%, 59.5% and 52.5% for Textile Mill (Wundwin), whereas the removal percents of Pb 2+ and As 3+ ions were 65.7% and 49.4% for Battery Industry (Shwe Pyi Thar) by using prepared geopolymer (H1). Thus the process of removal of the toxic metal ions from wastewater sample by kaolinite and fly ash-based geopolymers can be used as an effective alumino-silicate polymeric material in the treatment of industrial influents.