Dynamic linear adsorption with solid adsorbent material

A mathematical problem of linear physical adsorption of a dissolved impurity is formulated, by consider-ing its diffusion transfer during the filtration of an aqueous suspension through a uniform adsorbent bed at a constant rate. By averaging the impurity concentrations in the free and bound states over an arbi-trary time period, an approximate solution of the problem is obtained, which is only expressed in terms of the elementary functions. On its basis, it is proposed to calculate the rational duration of the filter run. The solution is discussed and illustrated with a number of examples with typical input data.

Finding the Specific Surface Area of an Organomineral Sorbent Produced by Electroplasma Treatment of Coal Flotation Waste

This paper dwells upon finding the specific surface area of cake, a coal enrichment waste, exposed to electroplasma treatment; the goal is to make an organomineral porous material to be used as a sorbent for wastewater treatment. The research team used a monomolecular Langmuir adsorption model and surface tension of the surfactants before and after adsorption at the interface of solution and solid adsorbent. Another process considered herein was thermal activation of substances in the electroplasmic reactor for making organomineral porous materials from coal cakes. The paper presents the resulting specific surfaces area of the organomineral sorbent thus produced. Thus, the waste of flotation, i.e. coal cake, is fundamentally suitable for making porous substances by thermal destruction in an electroplasma reactor.

An Overview of the Sorption Studies of Contaminants on Poly(Ethylene Terephthalate) Microplastics in the Marine Environment

Marine pollution is one of the biggest environmental problems, mainly due to single-use or disposable plastic waste fragmenting into microplastics (MPs) and nanoplastics (NPs) and entering oceans from the coasts together with human-made MPs. A rapidly growing worry concerning environmental and human safety has stimulated research interest in the potential risks induced by the chemicals associated with MPs/NPs. In this framework, the present review analyzes the recent advances in adsorption and desorption studies of different contaminants species, both organic and metallic, on MPs made of Poly(Ethylene terephthalate). The choice of PET is motivated by its great diffusion among plastic items and, unfortunately, also in marine plastic pollution. Due to the ubiquitous presence of PET MPS/NPs, the interest in its role as a vector of contaminants has abruptly increased in the last three years, as demonstrated by the very high number of recent papers on sorption studies in different environments. The present review relies on a chemical engineering approach aimed at providing a deeper overview of both the sorption mechanisms of organic and metal contaminants to PET MPs/NPs and the most used adsorption kinetic models to predict the mass transfer process from the liquid phase to the solid adsorbent.

Kinetic, equilibrium and thermodynamic studies of the adsorption of paracetamol in activated carbon in batch model and fixed-bed column

This work studied the removal of paracetamol through the adsorption process using the granular activated carbon. The results indicated that it was possible to obtain 95% of removal under the experimental conditions of pH 6, 120 min of process and 5 g L−1 of solid adsorbent. The kinetic model that best fit the experimental data was the pseudo-first order. The isotherm model that best fit the experimental data was the Sips. The thermodynamic tests indicated that the adsorption process was favorable and spontaneous and confirmed the endothermic nature of the process. In fixed bed column adsorption, the best operating condition found was obtained using the flow rate of 3 mL min−1 and bed mass equal to 0.5 g. In this case, the system presented the highest volume of treated PAR effluent, of 810 mL per gram of carbon in the bed, besides a longer rupture time and bed saturation.

Ultrathin porous amine-based solid adsorbent incorporated zeolitic imidazolate framework-8 membrane for gas separation

The amine-based solid adsorbent was innovatively incorporated during the fabrication of the ZIF-8 membrane for gas separation.

Preparation and Characterization of Amine-Functionalized Mesoporous Hollow Silica for CO2 Capture

Mesoporous hollow silica material (MHS) was synthesized using polystyrene as a template. Later, it was modified by wet impregnation with tetraethylenepentamine (TEPA) as a solid adsorbent for CO2 capture. Transmission electron microscopy (TEM), X-ray diffraction (XRD), IR, and TGA were used to characterize the average diameter, shell thickness, crystalline structure, and TEPA load of the prepared adsorbents. An increase in the amount of loaded TEPA, improved the CO2 adsorption capacity of the prepared adsorbents. The highest CO2 adsorption capacity was obtained using a 50 wt% TEPA load (AMHS-50).

The potential of biocarbon as CO2 adsorbent in VPSA unit

The best solution to the main environmental problem seems to be CO2 capture to reduce greenhouse gas emissions. The activated carbons derived from biomass have attracted extensive attention as solid adsorbent for carbon dioxide capture process. In this work, we focus on examining the properties of biochar (non-activated porous carbon) produced from biomass. Physicochemical properties of the biochar were investigated by thermogravimetric analysis (TG), Fourier transform infrared spectroscopy, scanning electron microscopy and N2 adsorption–desorption at 77 K. In order to evaluate the possibility of using biocarbons for CO2 adsorption in large-scale VPSA units, investigations of these adsorbents in laboratory are necessary. The paper present the potential of biochar for CO2 capture in VPSA unit. The examination of the CO2 sorptive capability, stability and regeneration performance of biochar was carried out using a Mettler-Toledo TGA/SDTA 851e thermobalance and TG-Vacuum system. The sorption of CO2 was carried out isothermally in a flow of a mixture of gasses: CO2 (100 vol.%) and CO2 (16 vol.%)/N2 (84 vol.%). The commercial biochar showed a sorption performance for CO2 up to 26.4 mg CO2 g−1 adsorbent at 30 °C and 30 bar. Repeated use of the adsorbent in the sorption/desorption cycle did not affect its performance, which indicates high sorption stability.

Adsorção de cromo hexavalente usando rejeito de beneficiamento de carvão em modelo de batelada e coluna de leito fixo

The objective of this work is to utilize a coal beneficiation tailing from Moatize (Mozambique) for the adsorption of hexavalent chromium from water in batch model and fixed bed column. Coal waste was used in particle size between 0.7 and 1.5 mm. The effects of pH, contact time and solid adsorbent concentration were analyzed by batch experiments. The results indicated that it was possible to obtain 98.6% of removal under the experimental conditions of pH 2, 10 h of process and 8 g.L-1 of solid adsorbent. From these experimental results, equilibrium isotherms were build and Langmuir and Sips models presented a better fit to the experimental data. The adsorption of chromium hexavalent from aqueous solution onto coal waste was investigated in a fixed bed column at 298 K. The effects of the inlet concentration, feed flow rate, bed depth on adsorption were investigated. In general, the evaluated parameters improved as a results increase in a Z (bed deep) and decreases in Q (feed flow rate). These performance metrics also improved as C0 (inlet concentration) was increased.

The Effectiveness Adsorption of Au(III) and Cu(II) Ion by Mangosteen Rind (Garcinia mangostana L.) Using Point of Zero Charge Calculation

Adsorption of Au(III) and Cu(II) by mangosteen rind adsorbent had been carried out. Mangosteen rind has several functional groups including –OH phenolics, ‒C=C‒ aromatics, and ethers. Dried mangosteen rind which was obtained from maceration was used to determine Point of Zero Charge (PZC). The most effective pH adsorption was determined by mixing adsorbent with Au(III) or Cu(II) solutions with various pH. The adsorption capacity was affected by the interaction between adsorbent and adsorbate. The solid adsorbent before and after interaction was characterized by FTIR, XRD, and microphotography. The PZC pH value of adsorbent was 3.7 while the optimum pH for Au(III) and Cu(II) were at pH 2 and pH 5, respectively. The adsorption capacity (qmax) value was 333.33 mg/g by following the Langmuir isotherm equation. The crystalline structure of adsorbent was analyzed using XRD and gave 4 peaks characteristics of gold metal on 2ϴ = 38º, 44º, 64º, and 77º after adsorption which indicated the reduction of Au(III) ions into Au(0).