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Environmental Science and Pollution... Jun 2023Adsorptive separation of heavy metals from wastewater is a viable approach to reuse it and avoid environmental pollution. The productive employment of adsorptive...
Adsorptive separation of heavy metals from wastewater is a viable approach to reuse it and avoid environmental pollution. The productive employment of adsorptive separation at a commercial scale, however, relies on the optimized conditions of an adsorber bed holding maximum and selective isolation of the heavy metals. The experimental route includes a significant trial and error approach, is time-consuming, involves operating cost, and remains economically unattractive. Contrarily, simulation of a mathematical model mimicking the adsorption system along with experimental validation can significantly minimize optimization efforts and suggests the best conditions of separation. In this work, a convective-dispersive model and adsorption model for fixed bed adsorption of copper (Cu), chromium (Cr), and cadmium (Cd) metals over wheat bran biosorbent are simulated using the gPROMS tool for benchmarking. The influence of feed flow rate, bed height, and metal concentration is studied, and breakthrough profiles of all heavy metals are predicted and matched with the literature. The error values (R and RMSE) and Chi-squared values determined from gPROMS simulations matched well with the previously available MATLAB-simulated data. After a successful benchmarking, we modeled pilot-scale adsorption of Cr on coconut coir (or Biosorbent) in a gPROMS simulation environment. A detailed method and algorithm of gPROMS simulation for Cr isolation is provided. The influence of feed flow rate, bed height, and initial metal concentration is studied on the breakthrough curves of the Cr. The optimum operating condition for the pilot-scale isolation of Cr from the water is suggested. The parameters, such as the axial dispersion coefficient and distribution coefficient, are determined.
Topics: Adsorption; Benchmarking; Water Pollutants, Chemical; Metals, Heavy; Chromium; Cadmium; Hydrogen-Ion Concentration
PubMed: 33674977
DOI: 10.1007/s11356-021-13207-y -
Journal of Environmental Management Jun 2021In the last decades, phosphate is considered the main cause of eutrophication and has received substantial attention from the scientific community. Phosphate is a major... (Review)
Review
In the last decades, phosphate is considered the main cause of eutrophication and has received substantial attention from the scientific community. Phosphate is a major pollutant that deteriorates water quality, which has been increasing in water resources, primarily due to the increasing global population and corresponding activities. Adsorption technology is amongst the different technologies used to decrease the phosphate levels in water, and has been found to be highly effective even at low phosphate concentrations. Carbonaceous materials and their composites have been widely used for phosphate removal due to their exceptional surface properties and high phosphate sorption capacity. Considering the importance of the topic, this study reviews the reported literature in the field of adsorptive removal of phosphate over various carbon-based adsorbents such as activated carbon, charcoal, graphene, graphene oxide, graphite and carbon nanotubes. Moreover, insights into the adsorption behaviour, experimental parameters, mechanisms, thermodynamics, effect of coexisting ions and the possible desorption processes of phosphate onto modified and unmodified carbonaceous adsorbents are also considered. Finally, research challenges and gaps have been highlighted.
Topics: Adsorption; Charcoal; Nanotubes, Carbon; Phosphates; Water; Water Pollutants, Chemical
PubMed: 33735679
DOI: 10.1016/j.jenvman.2021.112245 -
Environmental Science and Pollution... Feb 2021The present study, for the first time, utilized 3,4-diaminobenzophenone (DABP)-functionalized FeO/AC@SiO (FeO/AC@SiO@DABP) magnetic nanoparticles (MNPs) synthesized as a...
The present study, for the first time, utilized 3,4-diaminobenzophenone (DABP)-functionalized FeO/AC@SiO (FeO/AC@SiO@DABP) magnetic nanoparticles (MNPs) synthesized as a nanoadsorbent for enhancing adsorption and desorption capacity of gaseous benzene and toluene as volatile organic compounds (VOCs). The FeO/AC@SiO@DABP MNPs used in adsorption and desorption of benzene and toluene were synthesized by the co-precipitation and sol-gel methods. The synthesized MNPs were characterized by SEM, FTIR, TGA/DTA, and BET surface area analysis. Moreover, the optimization of the process parameters, namely contact time, initial VOC concentration, and temperature, was performed by applying response surface methodology (RSM). Adsorption results demonstrated that the FeO/AC@SiO@DABP MNPs had excellent adsorption capacity. The maximum adsorption capacities for benzene and toluene were found as 530.99 and 666.00 mg/g, respectively, under optimum process parameters (contact time 55.47 min, initial benzene concentration 17.57 ppm, and temperature 29.09 °C; and contact time 57.54 min, initial toluene concentration 17.83 ppm, and temperature 27.93 °C for benzene and toluene, respectively). In addition to the distinctive adsorptive behavior, the FeO/AC@SiO@DABP MNPs exhibited a high reproducibility adsorption and desorption capacity. After the fifth adsorption and desorption cycles, the FeO/AC@SiO@DABP MNPs retained 94.4% and 95.4% of its initial adsorption capacity for benzene and toluene, respectively. Kinetic and isotherm findings suggested that the adsorption mechanisms of benzene and toluene on the FeO/AC@SiO@DABP MNPs were physical processes. The results indicated that the successfully synthesized FeO/AC@SiO@DABP MNPs can be applied as an attractive, highly effective, reusable, and cost-effective adsorbent for the adsorption of VOC pollutants.Graphical abstract.
Topics: Adsorption; Benzophenones; Magnetic Phenomena; Phenylenediamines; Reproducibility of Results; Silicon Dioxide; Volatile Organic Compounds
PubMed: 32964387
DOI: 10.1007/s11356-020-10885-y -
Environmental Research Nov 2023Adsorptive removal of heavy metal ions from water is an energy- and cost-effective water decontamination technology. Schiff base functionalities can be incorporated into... (Review)
Review
Adsorptive removal of heavy metal ions from water is an energy- and cost-effective water decontamination technology. Schiff base functionalities can be incorporated into the pore cages of metal-organic frameworks (MOFs) via direct synthesis, post-synthetic modification, and composite formation. Such incorporation can efficiently enhance the interactions between the MOF adsorbent and target heavy metal ions to promote the selective adsorption of the latter. Accordingly, Schiff base-functionalized MOFs have great potential to selectively remove a particular metal ion from the aqueous solutions in the presence of coexisting (interfering) metal ions through the binding sites within their pore cages. Schiff base-functionalized MOFs can bind divalent metal ions (e.g., Pb(II), Co(II), Cu(II), Cd (II), and Hg (II)) more strongly than trivalent metal ions (e.g., Cr(III)). The adsorption capacity range of Schiff base-functionalized MOFs for divalent ions is thus much more broad (22.4-713 mg g) than that of trivalent metal ions (118-127 mg g). To evaluate the adsorption performance between different adsorbents, the two parameters (i.e., adsorption capacity and partition coefficient (PC)) are derived and used for comparison. Further, the possible interactions between the Schiff base sites and the target heavy metal ions are discussed to help understand the associated removal mechanisms. This review delivers actionable knowledge for developing Schiff-base functionalized MOFs toward the adsorptive removal of heavy metal ions in water in line with their performance evaluation and associated removal mechanisms. Finally, this review highlights the challenges and forthcoming research and development needs of Schiff base-functionalized MOFs for diverse fields of operations.
Topics: Metal-Organic Frameworks; Water; Schiff Bases; Decontamination; Metals, Heavy; Adsorption; Water Pollutants, Chemical
PubMed: 37541413
DOI: 10.1016/j.envres.2023.116811 -
Journal of Environmental Science and... 2021The objective of the study is to investigate the potential of carbide-derived carbon (CDC) for the adsorptive removal of nonionic -octylphenoxy poly ethoxy ethanol...
The objective of the study is to investigate the potential of carbide-derived carbon (CDC) for the adsorptive removal of nonionic -octylphenoxy poly ethoxy ethanol (TX-100), anionic sodium dodecylbenzene sulfonate (SDBS) and cationic 1-hexadecylpyridinium bromide (HDPB) surfactants from water. The CDC was characterized using TEM, SEM, FTIR, BET, EDS, XPS methods and zeta potential measurements. The effects of adsorption parameters included initial surfactant concentration, contact time, temperature, and pH of the feed solution were evaluated. The adsorption capacity and mechanism were determined by modeling the isotherm, kinetic and thermodynamic data. The kinetics results demonstrated that the adsorption of the surfactant by CDC obeys the pseudo 2 order model. The thermodynamic results have shown that surfactants adsorption by CDC is an endothermic and spontaneous process. The Sips model agreed with the adsorption isotherm data of SDBS with of 0.987, while both Freundlich and Redlich-Peterson models comply well with adsorption data for TX-100 and HDPB. The hydrophobic and electrostatic interactions were found the dominant mechanisms of the adsorption of the surfactant by CDC. The adsorption capacities of CDC were found to be 442.4, 462.0 and 578.4 mg/g for SDBS, HDPB and TX-100, respectively.
Topics: Adsorption; Carbon; Hydrogen-Ion Concentration; Kinetics; Surface-Active Agents; Thermodynamics; Water; Water Pollutants, Chemical
PubMed: 34618658
DOI: 10.1080/10934529.2021.1973822 -
Journal of Environmental Management Jan 2022The hydrothermal carbonization process is a suitable process for the conversion of potentially harmful lignocellulosic waste into hydrochars. Defective coffee beans were...
The hydrothermal carbonization process is a suitable process for the conversion of potentially harmful lignocellulosic waste into hydrochars. Defective coffee beans were the precursor raw material for hydrochar synthesis. Reactions were performed in a high-pressure reactor at 150, 200, and 250 °C, in autogenous pressure, for 40 min. Hydrochars were recovered by filtration and characterized by energy dispersive X-ray fluorescence spectroscopy, UV-Vis spectrophotometry, attenuated total reflection Fourier-transform infrared spectroscopy, differential thermal analysis, and scanning electron microscopy. Methylene blue adsorption tests were performed and analyzed by Langmuir and Freundlich adsorption isotherms. Adsorption mechanisms were investigated by computational calculations at DFT level. Results suggest that hydrochars from defective coffee beans can be applied as technological resources in the agronomic and environmental fields due to their inorganic composition, mainly to high magnesium content, the structural characteristics of porosity, biodegradation control, soil carbon-fixation and adsorption capacity. Important adsorption processes are caused by the development of oxygenated functional groups on the hydrochar surface.
Topics: Adsorption; Carbon; Coffee; Soil; Spectroscopy, Fourier Transform Infrared
PubMed: 34717105
DOI: 10.1016/j.jenvman.2021.114021 -
Journal of Environmental Management Nov 2023Natural soil components, such as clays, have recently piqued interest because of their potential as pesticide adsorbents. This research work sheds light on the...
Natural soil components, such as clays, have recently piqued interest because of their potential as pesticide adsorbents. This research work sheds light on the possibility of the application of natural Albanian clays as adsorbents for methomyl and dimethoate pesticides from aqueous solutions. Natural Albanian clays from the regions of Brari, Currila, Dardha, and Prrenjasi were employed in the study and were characterized by granulometric analysis and powder X-ray diffraction. Each clay's adsorption capacity and desorption behavior were investigated toward the chosen pesticides. Within 48 h of contact time, methomyl and dimethoate solutions with different concentrations were evaluated at 25 °C to see how the insecticide concentration affected the adsorption & desorption processes for each natural clay type. The experimental data were fitted to Freundlich, Temkin and Dubinin-Radushkevich isotherm like functions and the results showed the best correlation on Freundlich like adsorption isotherm for almost all cases. Brari clay performed better adsorptive properties toward dimethoate, followed by Dardha, Currila and Prrenjasi clays. The dimethoate adsorbed quantities varied from 0.250 mg/g for C = 0.200 g/L to 0.822 mg/g for C = 0.500 g/L. In comparison to Dardha and Prrenjasi clays, Brari and Currila clays exhibit longer saturation times and improved methomyl retention. In the first 2 h of contact, 96.5% of methomyl and 81% of dimethoate were desorbed from Brari clay. The adsorption process was also investigated employing pseudo first-order and pseudo second-order kinetic models, with the results indicating that all clay-pesticide systems studied demonstrated second-order kinetic behavior. Based on the studied desorption process, it is possible to impregnate clays with various insecticides in agriculture and completely control the quantities of the insecticide released.
Topics: Clay; Pesticides; Methomyl; Dimethoate; Insecticides; Adsorption; Kinetics
PubMed: 37717393
DOI: 10.1016/j.jenvman.2023.118989 -
Journal of Hazardous Materials Feb 2022Effective elimination of heavy metal ions from water is an arduous task for their toxic effects to aquatic ecosystem and human health. Herein, a novel alkynyl...
Effective elimination of heavy metal ions from water is an arduous task for their toxic effects to aquatic ecosystem and human health. Herein, a novel alkynyl functionalized molybdenum disulfide (C-MoS) is fabricated via mechanochemical method with well interlayered spacing, meso porosity, and high surface area (~211 mg). Mineral MoS was first peeled mechanically and oxidized in situ to MoSO, and then reduced by ball milling with CaC to form the C-MoS composite. The as-obtained C-MoS shows extraordinary adsorptivity for heavy metal ions, viz. 1194 mg-Hg g (Hg(NO) solution, pH= 5, 303.15 K, equilibrium Hg(II) concentration Ce= 36.9 μg·g, ionic strength I= 17.2 mmolL), and 442.3 mg-Pbg (Pb(NO) solution, pH= 5, 303.15 K, equilibrium Pb(II) concentration Ce= 46.9μgg, I= 5.8 mmolL), respectively, along with excellent recyclability, representing one of the best sorbents till now. The adsorption isotherms of Hg(II) followed the Langmuir model and the adsorption kinetics followed the pseudo-second-order model. The adsorption is an endothermic and entropy driven spontaneous process. The excellent adsorption performance of C-MoS is attributed to its very high S-content, availability, and soft acid-base interaction with mercury and lead anions. The C-MoS is an advanced sorbent for Hg(II) and Pb(II) with excellent adsorption performance and recyclability.
Topics: Adsorption; Ecosystem; Humans; Hydrogen-Ion Concentration; Ions; Kinetics; Molybdenum; Water Pollutants, Chemical
PubMed: 34736210
DOI: 10.1016/j.jhazmat.2021.127579 -
Advances in Colloid and Interface... Mar 2022Protein surfactant (PS) interactions is an essential topic for many fundamental and technological applications such as life science, nanobiotechnology processes, food... (Review)
Review
Protein surfactant (PS) interactions is an essential topic for many fundamental and technological applications such as life science, nanobiotechnology processes, food industry, biodiesel production and drug delivery systems. Several experimental techniques and data analysis approaches have been developed to characterize PS interactions in bulk and at interfaces. However, to evaluate the mechanisms and the level of interactions quantitatively, e.g., PS ratio in complexes, their stability in bulk, and reversibility of their interfacial adsorption, new experimental techniques and protocols are still needed, especially with relevance for in-situ biological conditions. The available standard techniques can provide us with the basic understanding of interactions mainly under static conditions and far from physiological criteria. However, detailed measurements at complex interfaces can be formidable due to the sophisticated tools required to carefully probe nanometric phenomena at interfaces without disturbing the adsorbed layer. Tensiometry-based techniques such as drop profile analysis tensiometry (PAT) have been among the most powerful methods for characterizing protein's and surfactant's adsorption layers at interfaces via measuring equilibrium and dynamic interfacial tension and dilational rheology analysis. PAT provides us with insightful data such as kinetics and isotherms of adsorption and related surface activity parameters. However, the data analysis and interpretation can be challenging for mixed protein-surfactant solutions via standard PAT experimental protocols. The combination of a coaxial double capillary (micro flow exchange system) with drop profile analysis tensiometry (CDC-PAT) is a promising tool to provide valuable results under different competitive adsorption/desorption conditions via novel experimental protocols. CDC-PAT provides unique experimental protocols to exchange the droplet subphase in a continuous dynamic mode during the in-situ analysis of the corresponding interfacial adsorbed layer. The contribution of diffusion/convection mechanisms on the kinetics of the adsorption/desorption processes can also be investigated using CDC-PAT. Here, firstly, we review the commonly available techniques for characterizing protein-surfactant interactions in the bulk phase and at interfaces. Secondly, we give an overview for applications of the coaxial double capillary PAT setup for investigations of mixed protein-surfactant adsorbed layers and address recently developed protocols and analysis procedures. Exploring the competitive sequential adsorption of proteins and surfactants and the reversibility of pre-adsorbed layers via the subphase exchange are the particular experiments we can perform using CDC-PAT. Also the sequential and simultaneous competitive adsorption/desorption processes of some ionic and nonionic surfactants (SDS, CTAB, DTAB, and Triton) and proteins (bovine serum albumin (BSA), lysozyme, and lipase) using CDC-PAT are discussed. Last but not least, the fabrication of micro-nanocomposite layers and membranes are additional applications of CDC-PAT discussed in this work.
Topics: Adsorption; Serum Albumin, Bovine; Surface Properties; Surface Tension; Surface-Active Agents
PubMed: 35114446
DOI: 10.1016/j.cis.2022.102601 -
Bioresource Technology May 2022Dye wastewater and discarded biofiber have brought huge pressure to sustainable developments of ecology and economy. By utilizing dopamine chemistry and benzophenone...
Dye wastewater and discarded biofiber have brought huge pressure to sustainable developments of ecology and economy. By utilizing dopamine chemistry and benzophenone mediated "grafting onto" atom transfer radical polymerization (ATRP), this work reported a biomass adsorbent containing discarded wool substrate, photocatalytic PDA coating and zwitterionic polymer brushes for dyes removal. The grafted zwitterionic polymer brushes impart the material with not only high adsorption capacity and rapid adsorption rate, but also switchable adsorption selectivity and pH-controlled regeneration capability. Benefiting from such outstanding adsorption performance and excellent free-standing property, the adsorbent could fulfill diversified needs of both static and dynamic adsorptions. Under daylight, the constructed photocatalytic PDA coating could in-situ degrade the captured pollutant, thus achieving consecutive adsorption-degradation-regeneration utilization. Furthermore, through simple dip-coating and cleaner UV-irradiation techniques, the preparation process could be scaled up. This work contributes to both the upcycling of discarded biofiber waste and the development of advanced biomass adsorbent.
Topics: Adsorption; Animals; Coloring Agents; Polymerization; Polymers; Wastewater
PubMed: 35351559
DOI: 10.1016/j.biortech.2022.127080