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Environmental Pollution (Barking, Essex... Jan 2022The production of biochar from sewage sludge pyrolysis is a promising approach to transform the waste resultant from wastewater treatment plants (WWTPs) to a potential... (Review)
Review
The production of biochar from sewage sludge pyrolysis is a promising approach to transform the waste resultant from wastewater treatment plants (WWTPs) to a potential adsorbent. The current review provides an up-to-date review regarding important aspects of sewage sludge pyrolysis, highlighting the process that results major solid fraction (biochar), as high-value product. Further, the physio-chemical characteristics of sewage-sludge derived biochar such as the elemental composition, specific surface area, pore size and volume, the functional groups, surface morphology and heavy metal content are discussed. Recent progress on adsorption of metals, emerging pollutants, dyes, nutrients and oil are discussed and the results are examined. The sewage sludge-derived biochar is a promising material that can make significant contributions on pollutants removal from water by adsorption and additional benefit of the management of huge volume of sewage. Considering all these aspects, this field of research still needs more attention from the researchers in the direction of the technological features and sustainability aspects.
Topics: Adsorption; Charcoal; Environmental Pollutants; Metals, Heavy; Sewage; Wastewater
PubMed: 34861332
DOI: 10.1016/j.envpol.2021.118581 -
Journal of Chromatography. A Jan 2022To interpret the dependence of solute retention behavior on modifier content in reversed-phase liquid chromatography, a theoretical framework, based on the concentration...
To interpret the dependence of solute retention behavior on modifier content in reversed-phase liquid chromatography, a theoretical framework, based on the concentration dependence of solvophobic forces imposed on solutes and the competitive adsorptions of solutes and solvent modifiers, was proposed. The generality of the developed model was demonstrated by comparing the model with conventional retention models. The linear dependence of the Gibbs energy change of solute adsorption with respect to the modifier concentration was assumed, and the model was fitted to the experimental results, with good agreement demonstrated between the experimental data and the model. Retention behaviors were inferred to be determined by two key dimensionless groups that represented the reductions in the retention factors resulting from a weakened solvophobic interaction and modifier competitive adsorption. The retention behaviors were successfully deconvoluted for each contribution as a function of the modifier concentration by using the fitted parameters. The effects of both contributions on the retention behaviors were enhanced for the solutes with aromatic groups. The standard Gibbs energy change of benzene adsorption was found to depend linearly on the number of modifier molecules present but independent of modifier identity. For the solutes associated with hydrogen-bonding groups, the degree of reduction in the solvophobic interactions was considerably reduced. Hence, the relative contributions of both mechanisms to solute retention depend greatly on the solute structure. Perturbation method was performed to investigate the modifier adsorption mechanisms. The results show that the standard Gibbs energy change for the first-layer adsorption of modifiers changed linearly with the carbon number of modifier molecule. These results demonstrated that the proposed model can offer a physically consistent quantitative description of retention when solvent composition is varied.
Topics: Adsorption; Amylose; Chromatography, Reverse-Phase; Solvents; Thermodynamics
PubMed: 34923304
DOI: 10.1016/j.chroma.2021.462736 -
Chemosphere Dec 2021Water is a basic and significant asset for living beings. Water assets are progressively diminishing due to huge populace development, industrial activities,... (Review)
Review
Water is a basic and significant asset for living beings. Water assets are progressively diminishing due to huge populace development, industrial activities, urbanization and rural exercises. Few heavy metals include zinc, copper, lead, nickel, cadmium and so forth can easily transfer into the water system either direct or indirect activities of electroplating, mining, tannery, painting, fertilizer industries and so forth. The different treatment techniques have been utilized to eliminate the heavy metals from aquatic system, which includes coagulation/flocculation, precipitation, membrane filtration, oxidation, flotation, ion exchange, photo catalysis and adsorption. The adsorption technique is a better option than other techniques because it can eliminate heavy metals even at lower metal ions concentration, simplicity and better regeneration behavior. Agricultural wastes are low-cost biosorbent and typically containing cellulose have the ability to absorb a variety of contaminants. It is important to note that almost all agro wastes are no longer used in their original form but are instead processed in a variety of techniques to improve the adsorption capacity of the substance. The wide range of adsorption capacities for agro waste materials were observed and almost more than 99% removal of toxic pollutants from aquatic systems were achieved using modified agro-waste materials. The present review aims at the water pollution due to heavy metals, as well as various heavy metal removal treatment procedures. The primary objectives of this research is to include an overview of adsorption and various agriculture based adsorbents and its comparison in heavy metal removal.
Topics: Adsorption; Charcoal; Water Pollutants, Chemical; Water Purification
PubMed: 34252804
DOI: 10.1016/j.chemosphere.2021.131438 -
Chemosphere Oct 2023Aminoglycoside antibiotics (AGs) in environmental water are emerging pollutants that must be removed to protect human health and the ecosystem. However, removing AGs...
Aminoglycoside antibiotics (AGs) in environmental water are emerging pollutants that must be removed to protect human health and the ecosystem. However, removing AGs from environmental water remains a technical challenge due to high polarity, stronger hydrophilicity and unique characteristics of polycation. Herein, a thermal-crosslinked polyvinyl alcohol electrospun nanofiber membrane (T-PVA NFsM) is synthesized and firstly leveraged as the adsorptive removal of AGs from environmental water. The thermal crosslinking strategy is demonstrated to enhance both the water resistance and hydrophilicity of T-PVA NFsM, thereby effectively interacting with AGs with high stability. Experimental characterizations and analog calculations indicate that T-PVA NFsM utilizes multiple adsorption mechanisms, including electrostatic and hydrogen bonding interactions with AGs. As a result, the material achieves 91.09%-100% adsorption efficiencies and a maximum adsorption capacity of 110.35 mg g in less than 30 min. Furthermore, the adsorption kinetics follow the pseudo-second-order model. After eight consecutive adsorption-desorption cycles, T-PVA NFsM with a simplified recycling process maintains a sustainable adsorption capability. Compared with other forms of adsorption materials, T-PVA NFsM has significant advantages such as less consumption of adsorbent, high adsorption efficiency and fast removal speed. Therefore, T-PVA NFsM-based adsorptive removal holds promise for eliminating AGs from environmental water.
Topics: Humans; Adsorption; Water; Ecosystem; Anti-Bacterial Agents; Water Pollutants, Chemical; Aminoglycosides; Kinetics; Hydrogen-Ion Concentration; Polyvinyl Alcohol
PubMed: 37422219
DOI: 10.1016/j.chemosphere.2023.139379 -
PeerJ 2022To realize simultaneous adsorption of heavy metal and antibiotic pollutants by a BC-based recyclable material, FeO magnetic biochar (MBC) was prepared by...
To realize simultaneous adsorption of heavy metal and antibiotic pollutants by a BC-based recyclable material, FeO magnetic biochar (MBC) was prepared by co-precipitation method. Then different ratios of dodecyl dimethyl betaine (BS-12)-modified bentonite (BS-B) were loaded on the surfaces of biochar (BC) and MBC to prepare BS-B-loaded BC and MBC composites, called BS-B/BC and BS-B/MBC, respectively. The physicochemical and structural properties of the composites were characterized by scanning electron microscopy, Fourier transform infrared spectrometry, thermogravimetric analysis, specific surface area (S) analysis, and vibrating sample magnetometry, and the adsorption efficiencies of BS-B/BC and BS-B/MBC to Cu and tetracycline (TC) were studied. The following results were obtained. (1) Compared with BS-B/BC, BS-B/MBC had decreased pH and cation exchange capacity (CEC) and increased S. The pH, CEC, and S of BS-B/BC and BS-B/MBC decreased with the increase in the BS-12 proportion of BS-B. The surface of BS-B/MBC became rough after FeO loading. (2) The residual rate of BS-B/MBC was higher than that of BS-B/BC after high-temperature combustion, and the residual rate decreased with the increase in the BS-12 proportion of BS-B. The 2D infrared spectra showed that FeO and BS-12 were modified on the surface of BS-B/MBC. MBC and BS-B/MBC had splendid magnetism and could be separated by external magnetic field. (3) Compared with unmagnetized ones, the adsorption effects of Cu and TC on different BS-B/MBCs improved, and the average adsorption rate reached the largest value of 91.92% and 97.76%, respectively. Cu and TC adsorptions were spontaneous, endothermic, and entropy-increasing processes. The pH and S of the material had a great influence on Cu and TC adsorptions, respectively, than CEC.
Topics: Adsorption; Bentonite; Anti-Bacterial Agents; Tetracycline; Magnetic Phenomena
PubMed: 35251788
DOI: 10.7717/peerj.13030 -
Water Research Jun 2023The coexistence of pharmaceuticals and heavy metals is regarded as a serious threat to aquatic environments. Adsorbents have been widely applied to the simultaneous... (Review)
Review
The coexistence of pharmaceuticals and heavy metals is regarded as a serious threat to aquatic environments. Adsorbents have been widely applied to the simultaneous removal of pharmaceuticals and metals from aqueous phase. Through a comprehensive review, behaviors that promote, inhibit, or have no effect on simultaneous adsorption of pharmaceuticals and heavy metals were found to depend on the system of contaminants and adsorbents and their environmental conditions, such as: characteristics of adsorbent and pollutant, temperature, pH, inorganic ions, and natural organic matter. Bridging and competition effects are the main reasons for promoting and inhibiting adsorption in coexisting systems, respectively. The promotion is more significant in neutral or alkaline conditions. After simultaneous adsorption, a solvent elution approach was most commonly used for regeneration of saturated adsorbents. To conclude, this work could help to sort out the theoretical knowledge in this field, and may provide new insights into the prevention and control of pharmaceuticals and heavy metals coexisting in wastewater.
Topics: Adsorption; Water Pollutants, Chemical; Metals, Heavy; Wastewater; Water; Pharmaceutical Preparations
PubMed: 37030197
DOI: 10.1016/j.watres.2023.119924 -
Chemosphere Dec 2022While nuclear energy with zero carbon emissions will continue to occupy an indispensable position in future scenarios for power generation, the proper disposal of... (Review)
Review
While nuclear energy with zero carbon emissions will continue to occupy an indispensable position in future scenarios for power generation, the proper disposal of nuclear waste is still highly challenging in many countries. Adsorption is currently one of the primary methods used for removal of cesium from wastewater. However, no available literature has systematically summarized advances and outlooks on the adsorptive removal of cesium, and research issues such as relevant adsorption mechanisms remain largely unexplored. In this study, a bibliometric analysis was used to quantitatively analyze 10141 publications in the Web of Science Core Collection that were published from 1900 to 2022. Current publication trends and active countries, most influential authors and institutions, journal distribution, and research hotspots and trends were reviewed and summarized. The results for the conceptual structure and evolution of investigations in this field showed three distinct periods of rapid development in recent decades. The first period concerned the scope, degree, and influences of pollution by cesium and the development of natural adsorbents. The second period included the exploration and verification of adsorption mechanisms, the fabrication and optimization of new materials, and the application of density functional theory for chemical calculations. The third period involved the development of more advanced biodegradable, nanoscale and synthetic materials with great potential for use as adsorbents as well as advances in engineering applications. Notably, the study showed that it is necessary to further enhance application-driven laboratory investigations. Future directions for research were proposed, such as the investigation of complex adsorption mechanisms, development of new materials, and engineering applications of materials developed in the laboratory. The findings will provide valuable insights and serve as a reference for researchers and policymakers as they address the adsorptive remediation of cases of pollution by cesium.
Topics: Adsorption; Bibliometrics; Carbon; Cesium; Radioactive Waste; Wastewater
PubMed: 36113663
DOI: 10.1016/j.chemosphere.2022.136445 -
International Journal of Biological... May 2023GO/HEC/PGDE/FeO materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE),...
GO/HEC/PGDE/FeO materials were successfully fabricated using environmentally-friendly hydroxyethyl cellulose (HEC), poly(ethylene glycol) diglycidyl ether (PGDE), graphene oxide (GO) and magnetic FeO. Systematic investigations were completed to explore the influences of GO content in GO/HEC/PGDE/FeO and adsorption conditions on the adsorptions of cationic dyes (methylene blue (MB), crystal violet (CV)) and anionic dye acid blue 25 (AB-25). The increase of GO content can remarkably improve the adsorption capacity of GO/HEC/PGDE/FeO for the dyes. The three kinetic, four isothermic and three thermodynamic models were investigated to reveal the adsorption behaviors of the dyes. The formation of HEC/PGDE/FeO and adsorption mechanisms of the dyes by GO/HEC/PGDE/FeO were suggested. The GO/HEC/PGDE/FeO endowed with easy-fabrication, eco-friendly feature, efficient adsorption capacity of anionic/cationic dyes, convenient separation and reusability has potential applications in wastewater purification industry.
Topics: Coloring Agents; Cellulose; Adsorption; Graphite; Cations; Water Pollutants, Chemical
PubMed: 36921822
DOI: 10.1016/j.ijbiomac.2023.124022 -
Chemosphere Dec 2021Water pollution from synthetic dyes is a growing environmental concern because many dyes have carcinogenic effects on humans and aquatic life. Adsorption is a widely... (Review)
Review
Water pollution from synthetic dyes is a growing environmental concern because many dyes have carcinogenic effects on humans and aquatic life. Adsorption is a widely used technology for the separation and removal of dyes from wastewater. However, the dye removal process using conventional adsorbents is not sufficiently efficient for industrial wastewater. Metal-organic frameworks (MOFs) addresses these drawbacks. MOF showed excellent dye removal and degradation capacity owing to its multifunctionality, water-stability, large surface area, tunable pore size and recyclability. Magnetic MOFs retained excellent performance up to several consecutive cycles. Modified MOFs performed as Fenton-like catalysis process which generated abundant reactive radicals that degraded complex organic dyes into simple and less toxic forms which were further adsorbed onto the MOF. This review systematically compiles in-depth studies on the adsorptive removal of dyes from wastewater, MOF adsorption mechanisms, major influencing factors, to adsorption efficiency of MOFs. While all MOFs adsorb dyes through electrostatic attraction, the type of MOF, presence of functional groups, ligands, and pH significantly control the adsorption mechanism. Before developing an MOF, optimization and upgradation of factors and interaction between available adsorption site and adsorbate is needed. Finally, the prospects and new frontiers of MOFs in sustainable water treatment is discussed.
Topics: Adsorption; Coloring Agents; Humans; Metals; Wastewater; Water Purification
PubMed: 34198066
DOI: 10.1016/j.chemosphere.2021.131314 -
Anais Da Academia Brasileira de Ciencias 2023Despite being little explored for petroporphyrins recovery from oils and bituminous shales, adsorption and desorption processes can be feasible alternatives to obtain a...
Despite being little explored for petroporphyrins recovery from oils and bituminous shales, adsorption and desorption processes can be feasible alternatives to obtain a similar synthetic material, and to characterize their original organic materials. Experimental designs were used to analyze the effects of qualitative (e.g., type of adsorbent, solvent, and diluent) and quantitative (e.g., temperature and solid/liquid ratio) variables on the adsorptive and desorptive performance regarding nickel octaethylporphyrin (Ni-OEP) removal using carbon-based adsorbents. The evaluation variables, adsorption capacity (qe ) and desorption percentage (%desorption ) were optimized by means of the Differential Evolution algorithm. The most efficient adsorbent for removing/recovery Ni-OEP was activated-carbon coconut shell, in which dispersive π-π type and acid-base interactions were likely formed. The highest values of qe and %desorption were obtained using toluene as solvent, chloroform as diluent, 293 K as temperature, and 0.5 mg.mL-1 as solid/liquid ratio for adsorption, and a higher temperature (323 K) and lower solid/liquid ratio (0.2 mg.mL-1) for desorption. The optimization process resulted in qe of 6.91 mg.g-1 and %desorption of 35.2%. In the adsorption-desorption cycles, approximately 77% of the adsorbed porphyrins were recovered. The results demonstrated the potential of carbon-based materials as adsorbent materials for obtaining porphyrin compounds from oils and bituminous shales.
Topics: Nickel; Carbon; Adsorption; Porphyrins; Excipients; Solvents
PubMed: 37341271
DOI: 10.1590/0001-3765202320211598