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Environmental Science and Pollution... Feb 2022Nanoadsorbents having large specific surface area, high pore volume with tunable pore size, affordability and easy magnetic separation gained much popularity in recent... (Review)
Review
Nanoadsorbents having large specific surface area, high pore volume with tunable pore size, affordability and easy magnetic separation gained much popularity in recent time. Iron-based nanoadsorbents showed higher adsorption capacity for different pollutant removal from water among other periodic elements. Spinel ferrite nanomaterials among iron-bearing adsorbent class performed better than single iron oxide and hydroxides due to their large surface area, mesoporous pore, high pore volume and stability. This work aimed at focusing on water treatment using magnesium ferrite (MgFeO) nanomaterials. Synthesis routes, properties and pollutant adsorption were critically investigated to explore the performance of magnesium ferrite in water treatment. Structural and surface properties were greatly affected by the factors involved in different synthesis routes and iron and magnesium ratio. Complete removal of pollutants through adsorption was achieved using magnesium ferrite. Pollutant adsorption capacity of MgFeO and its modified forms was found several folds higher than FeO and FeO nanomaterials. In addition, MgFeO showed strong stability in water than other pure iron oxide and hydroxide. Modification with graphene oxide, activated carbon, biochar and silica was demonstrated to be beneficial for enhanced adsorption capacity. Complex formation was suggested as a dominant mechanism for pollutant adsorption. These nanomaterials could be a viable and competitive adsorbent for diverse pollutant removal from water.
Topics: Adsorption; Environmental Pollutants; Ferric Compounds; Kinetics; Magnesium Compounds; Water Pollutants, Chemical; Water Purification
PubMed: 34854003
DOI: 10.1007/s11356-021-17287-8 -
Environmental Technology May 2021A new polymeric adsorbent for Cr(VI) ions based on an expanded poly(tetrafluoroethylene) (ePTFE) film was prepared by the combined use of the pretreatment with oxygen...
A new polymeric adsorbent for Cr(VI) ions based on an expanded poly(tetrafluoroethylene) (ePTFE) film was prepared by the combined use of the pretreatment with oxygen plasma and photografting of 2-(dimethylamino)ethyl methacrylate (DMAEMA). The grafting of DMAEMA was characterized by XPS and FT-IR spectroscopic measurements. The adsorption behaviour of DMAEMA-grafted ePTFE (ePTFE-g-PDMAEMA) films was investigated as a function of the experimental parameters, such as the initial pH value, temperature, and grafted amount. The adsorption capacity and initial adsorption rate had the maximum values at the initial pH value of 3.0. On the other hand, the adsorption capacity became almost constant at temperatures higher than 30°C, although the adsorption rate increased over the temperature. The adsorption behaviour obeyed the pseudo-second-order kinetic model and well expressed by the Langmuir isotherm equation with higher correlation coefficients. These results indicate that the adsorption of Cr(VI) ions occurs through the electrostatic interaction between protonated dimethylamino groups on a grafted PDMAEMA chain and ions. Cr(VI) ions were successfully desorbed from Cr(VI)-loaded ePTFE-g-PDMAEMA films in the eluents, such as NaCl at 0.50 M, NHCl at 0.50M, and NaOH at 1.0 mM, and ePTFE-g-PDMAEMA films were repeatedly used for adsorption of Cr(VI) ions without appreciable loss in the adsorption capacity. It should be noted that Cr(VI) ion adsorptivity with a high initial rate was conferred to the ePTFE films. The results obtained in this study emphasize that ePTFE-g-PDMAEMA films can be applied as an adsorbent for Cr(VI) ions.
Topics: Adsorption; Chromium; Ethylenes; Hydrogen-Ion Concentration; Ions; Kinetics; Methacrylates; Spectroscopy, Fourier Transform Infrared; Water Pollutants, Chemical
PubMed: 31631793
DOI: 10.1080/09593330.2019.1683612 -
Chemosphere Oct 2016Adsorptive removal of toxic compounds using advanced porous materials is one of the most attractive approaches. In recent years, the metal-organic frameworks (MOFs), a... (Review)
Review
Adsorptive removal of toxic compounds using advanced porous materials is one of the most attractive approaches. In recent years, the metal-organic frameworks (MOFs), a subset of advanced porous nano-structured materials, due to their unique characteristics are showing great promise for better adsorption/separation of various water contaminants. Given the importance of azo dye removal, as an important class of pollutants, this paper aims to review and summarize the recently published research on the effectiveness of various MOFs adsorbents under different physico-chemical process parameters in dyes adsorption. The effect of pH, the adsorption mechanism and the applicability of various adsorption kinetic and thermodynamic models are briefly discussed. Most of the results observed showed that the adsorption kinetic and isotherm of azo dyes onto the MOFs mostly followed the pseudo-second order and Langmuir models respectively. Also, the optimum pH value for the removal of majority of azo dyes by MOFs was observed to be in the range of ∼5-7.
Topics: Adsorption; Azo Compounds; Coloring Agents; Organometallic Compounds; Water Pollutants, Chemical; Water Purification
PubMed: 27355417
DOI: 10.1016/j.chemosphere.2016.06.065 -
Chemosphere Apr 2022Organic dyes, a type of high toxic and carcinogenic chemicals that present severe threats to human and aquatic life, are the most commonly seen organic pollutants in... (Review)
Review
Organic dyes, a type of high toxic and carcinogenic chemicals that present severe threats to human and aquatic life, are the most commonly seen organic pollutants in wastewater of industries such as textile, rubber, cosmetic industry etc. Various techniques for the removal of dyes are compared in this review. Adsorption has proven to be a facile and promising approach for the removal of dyes in wastewater. This work focuses on the latest development of various porous materials for the adsorption of organic dyes. The characteristics, functionalization and modification of different porous materials are also presented. Furthermore, adsorption behaviors and mechanism of these adsorbents in the adsorption of organic dyes are critically reviewed. Finally, challenges and opportunities for future research in the development of novel materials for the highly efficient removal of dyes are proposed.
Topics: Adsorption; Coloring Agents; Humans; Porosity; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 34974043
DOI: 10.1016/j.chemosphere.2021.133464 -
Molecules (Basel, Switzerland) Jan 2023The adsorption-desorption processes of organic pollutants into the soil are one of the main factors influencing their potential environmental risks and distribution in...
The adsorption-desorption processes of organic pollutants into the soil are one of the main factors influencing their potential environmental risks and distribution in the environment. In the present work, the adsorption-desorption behavior of an antibiotic, trimethoprim (TMP), and two of its main metabolites, 3-desmethyltrimethoprim (DM-TMP) and 4-hydroxytrimethoprim (OH-TMP), were assessed in three Mediterranean agricultural soils with different physicochemical characteristics. Results showed that the adsorption kinetic is performed in two steps: external sorption and intraparticle diffusion. The adsorptions of the studied compounds in soils were similar and fitted to the three models but were better fitted to a linear model. In the case of DM-TMP and OH-TMP, their adsorptions were positively correlated with the soil organic matter. In addition, desorption was higher in less organic matter soil (from 1.3 to 30.9%). Furthermore, the desorptions measured for the TMP metabolites were lower than those measured in the case of TMP (from 2.0 and 4.0% for OH-TMP and DM-TMP, respectively, to 9.0% for TMP).
Topics: Soil; Trimethoprim; Adsorption; Soil Pollutants; Thermodynamics
PubMed: 36615629
DOI: 10.3390/molecules28010437 -
Analytical Chemistry Jun 2021The study of the physicochemical process of volatile organic compound (VOC) adsorption on porous materials is significant for design and screening of adsorbent materials...
The study of the physicochemical process of volatile organic compound (VOC) adsorption on porous materials is significant for design and screening of adsorbent materials and treatment of VOCs. Traditional measurement methods for studying the adsorption process require lots of adsorbates and adsorbents and are time-consuming. We proposed a facile strategy to study the adsorption process of trace gaseous aldehydes on layered double hydroxide (LDH) using surface-enhanced Raman spectroscopy (SERS). We prepared a composite of Ag nanocubes@hollow Co-Ni LDH (AgNCs@Co-Ni LDH) with a strong adsorption capability and high SERS sensitivity. The adsorption properties of LDH for benzaldehyde in terms of general kinetics and isotherms were investigated. The kinetic adsorption process could be fitted better by the pseudo-first-order kinetics with a higher correlation coefficient than by the pseudo-second-order model, and the adsorption rate of 0.0308 min was obtained from the fitting curve. The isotherm adsorption fits the Langmuir isotherm model, and its adsorption constant is 6.25 × 10 L/mol. Taking advantage of the excellent adsorptive performance and SERS activity, the AgNCs@Co-Ni LDH composite can be used as an effective SERS probe to detect gaseous aldehydes, and it shows a linear dynamic range (5-100 ppb) with a limit of detection reaching 1.83 ppb for benzaldehyde, better than that achieved by previous studies. Therefore, this work has not only established a new measurement method for probing the adsorption process with extremely low consumption of both adsorbates and adsorbents, but also may lay the groundwork for the construction of rapid and ultra-sensitive SERS sensors for probing VOCs in the future.
Topics: Adsorption; Benzaldehydes; Hydroxides; Kinetics; Water Pollutants, Chemical
PubMed: 34076422
DOI: 10.1021/acs.analchem.1c00958 -
Environmental Monitoring and Assessment Aug 2023The recovery of organophosphate pesticides (OPPs) from aqueous solutions is imperative considering their agricultural and environmental implications. Among various...
The recovery of organophosphate pesticides (OPPs) from aqueous solutions is imperative considering their agricultural and environmental implications. Among various mitigation approaches used for OPPs' removal, adsorption offers many advantageous features for OPPs abatement owing to its benign nature, cost-effective processing, and non-requirement of excessive equipment. This research describes the adsorptive removal of three organophosphate pesticides (OPPs) namely chlorpyrifos (CPF), methyl parathion (MP), and malathion (MAL) by HKUST-1 (HKUST = Hong Kong University of Science and Technology) metal-organic framework (MOF). The synthesis of HKUST-1 MOFs was confirmed by various spectroscopic and microscopic techniques. The adsorption kinetics was systematically investigated by varying three parameters to include solution pH, contact time, and initial pesticide concentration. Among all the three pesticides, HKUST-1 showed enhanced removal of CPF in terms of pH, resulting in an adsorption capacity of 1.82 mg·g. However, under the effect of contact time at 60 min, the adsorption capacity of HKUST-1 for PM, MAL, and CPF were computed to be 1.83, 1.79, and 0.44 mg·g, respectively. Besides, HKUST-1 showed a remarkable performance towards adsorptive removal of MAL (14.01 mg·g at 10 mg·L concentration) with linear increase in adsorption capacity as the function of initial pesticide concentration. The MOFs were also able to retain ca. 50% of their adsorption efficiency over the course of five cycles of adsorptive removal of CP. In the future, a comprehensive data table showing the performance of various MOFs against various OPPs can be constructed on the basis of parameters used in this study.
Topics: Metal-Organic Frameworks; Adsorption; Environmental Monitoring; Insecticides; Chlorpyrifos; Malathion; Pesticides; Organophosphorus Compounds
PubMed: 37592149
DOI: 10.1007/s10661-023-11662-3 -
Chemosphere Dec 2022Groundwater is usually utilized as a drinking water asset everywhere. Therefore, groundwater defilement by poisonous radioactive metals such as uranium (VI) is a major... (Review)
Review
Groundwater is usually utilized as a drinking water asset everywhere. Therefore, groundwater defilement by poisonous radioactive metals such as uranium (VI) is a major concern due to the increase in nuclear power plants as well as their by-products which are released into the watercourses. Waste Uranium (VI) can be regarded as a by-product of the enrichment method used to produce atomic energy, and the hazard associated with this is due to the uranium radioactivity causing toxicity. To manage these confronts, there are so many techniques that have been introduced but among those adsorptions is recognized as a straightforward, successful, and monetary innovation, which has gotten major interest nowadays, despite specific drawbacks regarding operational as well as functional applications. This review summarizes the various adsorbents such as Bio-adsorbent/green materials, metal oxide-based adsorbent, polymer based adsorbent, graphene oxide based adsorbent, and magnetic nanomaterials and discuss their synthesis methods. Furthermore, this paper emphasis on adsorption process by various adsorbents or modified forms under different physicochemical conditions. In addition to this adsorption mechanism of uranium (VI) onto different adsorbent is studied in this article. Finally, from the literature reviewed conclusion have been drawn and also proposed few future research suggestions.
Topics: Adsorption; Drinking Water; Hydrogen-Ion Concentration; Kinetics; Polymers; Uranium; Wastewater
PubMed: 36057349
DOI: 10.1016/j.chemosphere.2022.136278 -
Chemosphere Jan 2022Methylene blue (MB) is categorized as an organic dye (OD) released as effluents after various industrial activities and is one of the most abundant pollutants in the... (Review)
Review
Methylene blue (MB) is categorized as an organic dye (OD) released as effluents after various industrial activities and is one of the most abundant pollutants in the aquatic environment. Significantly, because of its potential toxicity, removing MB from wastewater has been a matter of necessity in recent times. Numerous analytical techniques have been applied, among which polysaccharide-based composite hydrogels appear as the most favorable for MB removal because of their large surface area, excellent mechanical properties, swelling capability, and large-scale production. In this review, the first section gives adequate information about the ODs' adverse effects on the environment and the contribution of polysaccharide-based hydrogels for OD removal, especially MB. Next, various mechanisms such as electrostatic interactions, π-π interactions, hydrogen bonding, hydrophobic interaction, van der Waals force, and coordination interaction involved in the adsorption technique are investigated. The third section extensively describes the MB removal by incorporation of various materials such as monomers, metal oxides, magnetic nanoparticles, and clay into the polysaccharide matrix to produce composite hydrogels. Finally, the current limitations and future perspectives of the polysaccharide-based composite hydrogel techniques are addressed. Overall, this review acknowledged the vital role of polysaccharide-based composite hydrogels for MB adsorption by surveying 110 research articles published in the past five years (2015-2021).
Topics: Adsorption; Environmental Pollutants; Hydrogels; Methylene Blue; Polysaccharides; Water Pollutants, Chemical
PubMed: 34426282
DOI: 10.1016/j.chemosphere.2021.131890 -
Chemosphere Mar 2024Per- and polyfluoroalkyl substances (PFAS) (also known as 'forever chemicals') have emerged as trace pollutants of global concern, attributing to their persistent and... (Review)
Review
Per- and polyfluoroalkyl substances (PFAS) (also known as 'forever chemicals') have emerged as trace pollutants of global concern, attributing to their persistent and bio-accumulative nature, pervasive distribution, and adverse public health and environmental impacts. The unregulated discharge of PFAS into aquatic environments represents a prominent threat to the wellbeing of humans and marine biota, thereby exhorting unprecedented action to tackle PFAS contamination. Indeed, several noteworthy technologies intending to remove PFAS from environmental compartments have been intensively evaluated in recent years. Amongst them, adsorption and photocatalysis demonstrate remarkable ability to eliminate PFAS from different water matrices. In particular, carbon-based materials, because of their diverse structures and many exciting properties, offer bountiful opportunities as both adsorbent and photocatalyst, for the efficient abatement of PFAS. This review, therefore, presents a comprehensive summary of the diverse array of carbonaceous materials, including biochar, activated carbon, carbon nanotubes, and graphene, that can serve as ideal candidates in adsorptive and photocatalytic treatment of PFAS contaminated water. Specifically, the efficacy of carbon-mediated PFAS removal via adsorption and photocatalysis is summarised, together with a cognizance of the factors influencing the treatment efficiency. The review further highlights the neoteric development on the novel innovative approach 'concentrate and degrade' that integrates selective adsorption of trace concentrations of PFAS onto photoactive surface sites, with enhanced catalytic activity. This technique is way more energy efficient than conventional energy-intensive photocatalysis. Finally, the review speculates the cardinal challenges associated with the practical utility of carbon-based materials, including their scalability and economic feasibility, for eliminating exceptionally stable PFAS from water matrices.
Topics: Humans; Adsorption; Nanotubes, Carbon; Bioaccumulation; Water; Fluorocarbons; Water Pollutants, Chemical
PubMed: 38215829
DOI: 10.1016/j.chemosphere.2024.141164