Use Of Adsorbents Research Articles

Hierarchically-porous resin for the adsorption of organic matter in raffinate produced by solvent extraction from the vanadium industry

Solvent extraction wastewater contains high concentrations of organic pollutants and metal ions, making it difficult to treat. This paper presents a method of using hierarchically-porous adsorption resin to recover organics from raffinate and regenerate the resin, addressing secondary pollution in extraction processes. The chosen resin, WS6108, removes over 95 % of organics from raffinate, with high metal ion concentrations enhancing its adsorption efficiency. The article conducted an optimization experiment and mechanism study on WS6108 resin for adsorbing organic matter in vanadium raffinate (OIVR), followed by desorption and recycling tests. Results showed WS6108 resin achieved a 96.7 % adsorption efficiency at a solid–liquid ratio of 24 g/L after optimization. The chosen methanol desorbent achieves over 99 % desorption efficiency for the WS6108 cycle under specific conditions. The resin’s performance remains stable for up to 45 cycles. Adsorption isotherms and kinetic experiments indicate that OIVR adsorption by WS6108 resin is endothermic, non-spontaneous and entropy increasing. Moreover, the adsorption kinetics of OIVR by WS6108 resin followed a pseudo-second-order model, based on the activation energy, liquid film diffusion was considered the main rate-controlling step. A column experiment was conducted to verify that WS6108 resin can be used in real vanadium raffinate to remove organics. Density functional theory (DFT) revealed that strong hydrogen bonding, π-π stacking and excellent adsorption diffusion behavior drive OIVR adsorption. This study aims to increase the use of adsorption to treat oily wastewater generated by solvent extraction.

Removal of Textile Dye Using a Low‑Cost Composite Film Based on PVA-Clay: Preparation, Characterization and RSM Optimization

The use of adsorbent materials in powder form presents significant challenges for industrial wastewater treatment due to their poor regeneration after use. Our research described here aimed to prepare a low-cost and eco-friendly film with excellent regeneration capabilities for the efficient removal of Telon Orange dye (TO) from water. The film was fabricated by incorporating a natural clay, DD3, into a poly (vinyl alcohol) (PVA) matrix using the solvent casting method. The prepared film was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA) techniques. The characterization results confirmed that the DD3 interacts and disperses within the PVA matrix. The influence of film dose and composition, pH, contact time, and initial concentration were studied in batch adsorption. Response surface methodology (RSM) using the Box-Behnken design matrix was then used to find the best conditions for dye adsorption. An ANOVA analysis approved the proposed quadratic model with a high correlation coefficients (R2 = 0.98). The F-value of the model was 46.39, indicating that the model was significant. The PVA/DD3 composite film achieved a 93.45% efficiency in removing TO dye under optimal conditions. The recyclability studies showed a removal efficiency of 90.13% after five uses of the film, making it suitable for large-scale applications and adaptable for use in water purification systems.

Development and assessment of vanadium-based metal–organic frameworks for the effective elimination of hazardous pesticides from aqueous solutions: Mechanism of uptake, adsorption capacities, rate of uptake, and enhancement via the Box-Behnken design

Vanadium metal–organic frameworks (V-MOF) has a great potential to remove contaminants from water that come from agriculture wastewater methyl parathion (MP) pesticides with high effectiveness. Using a variety of methods, such as SEM, FT-IR, XPS), XRD, and BET analysis, the adsorbent was successfully synthesized and characterized. The dimensions of the pores measured at 1.33 nm correspond to the classification of micropores under the IUPAC system. Before the adsorption process, the material had a surface area of 1489.42 m2/g and a pore volume of 0.98 cc/g. After MP adsorption, the surface area, pore size, and pore volume decreased to 1268.42 m2/g, 1.12 nm, and 0.64 cc/g, respectively. Changes in the material’s physical properties indicate that the adsorption process had an effect. 7.2 was the result of controlling the point of zero charge through surface characterization. This information suggests that the surface of the adsorbent has a positive charge at pH below 7.2 and at the pH higher than this value the surface will have a negative charge. It was also looked into how pH affected the adsorption equilibrium. Although fitting to Langmuir isothermally, the kinetics of MP adsorption onto V-MOF are pseudo-second-order fitting. It is very probable that chemisorption was the mode of adsorption because the adsorption energy was 23.62 kJ.mol−1. The enthalpy (ΔHo) values obtained as a result of studying the thermodynamic parameters are positive, demonstrating that, within this temperature range, the pesticide adsorption process was endothermic., measuring 32.79 kJ.mol−1. Entropy (ΔSo) readings that are positive indicate that the system’s randomness increased during the adsorption process, reaching 119 J.mol−1K−1, and with rising temperatures, the negative of ΔGo rise. The effectiveness of the recommended adsorbent was evaluated by filtering wastewater samples in a laboratory environment. It is hypothesized that V-MOF and MP will interact by pore filling, π-π interaction, H-bonding, electrostatic contact, and other possible methods. Considering the specifics of this interaction in great detail is essential to comprehending the nature of adsorption and effectively constructing the adsorbent for use in real-world applications. Water filtering and the treatment of industrial effluents were made simple and effective by the use of V-MOF adsorbent technology. The results indicated that 383.6 mg/g was the maximal adsorption capacity at pH = 6. To evaluate the renewal of the adsorbent, more tests were carried out, and the outcomes showed that the renewal continued even after more than six cycles. The stability of the adsorbent during regeneration was confirmed by using XRD and FT-IR. The Box Behnken design (BBD) was then employed to optimize the adsorption outcomes.

Enhanced cadmium (Cd2+) removal from wastewater using integrated inclined plate settler and composite adsorbent coating

Bottlenecks inherent in batch and column adsorption configurations have impeded the implementation of the adsorption technique in large-scale wastewater treatment systems. This study mainly aimed to develop an innovative wastewater treatment prototype that integrates inclined plate settlers (IPS) and composite adsorbent coating (CAC). The objective is to enable the removal of Cd2+ from aqueous solutions in a continuous setup, thereby enhancing its practicality for large-scale applications. The combined IPS-CAC system was optimized at various angle of inclination (θ), influent flow rate (Q) and adsorbate initial concentration (Co) using the Box–Behnken Design (BBD) of the Response Surface Methodology (RSM). At optimized operating parameters (θ = 45°, Q = 5 ml/min and Ci = 1.87 mg/L) the IPS-CAC Cd2+ predicted (R2 = 0.9926) and experimental removal efficiencies were 75.8% and 69.7 ± 4.67%, respectively. The IPS-CAC breakthrough adsorption capacity was 9.6 mg/g. Comparing IPS-CAC performance with a tank without plates and IPS with plain plates, the Cd2+ removal efficiencies were 2.4 ± 0.1% and 4.6 ± 1.1%, respectively, confirming the synergistic effect of IPS and CAC. Additionally, breakthrough curves were acquired for various flow rates, cadmium influent concentrations, and plate inclination angles. Only a 10% decline in the removal effectiveness (from 69.7 to 59.7%) of the CAC after three adsorption–regeneration cycles was observed, indicating its stability for heavy metal removal. The results underpin the potential of using IPS-CAC for industrial wastewater treatment and enhancing the use of adsorption on a larger scale.

Cobalt adsorption by Ca(OH)2 Modified quartz rock particles adsorbent: Equilibrium isotherm, kinetics, and thermodynamic studies

The presence of cobalt ions Co(II) in wastewater poses major threats to both humans and the environment. The effectiveness of the adsorption of modified quartz rock particles (MQRP) adsorbent with calcium hydroxide solution Ca(OH)2 for eliminating Co(II) from a water solution was examined. MQRP had a maximum ability to adsorb 47.112 mg g−1 for Co(II) at pH 6.0 and a contact time of 2 h. The HCl stripping agent offered the highest desorption efficiency to regenerate the adsorbent for use again for a new cycle of adsorption. The equilibrium isotherms of the adsorption characteristics were experimentally identified, and the results of adsorption aligned with the principles of the Langmuir model. Under the examined temperature conditions, thermodynamic evaluation proved that Co(II) adsorption on adsorbent vacancies was spontaneous and exothermic.The outcomes of the kinetic process demonstrated that the process closely conformed to a pseudo-second-order pattern. Therefore, the high silica content of MQRP makes it an important adsorbent, and it could be applied as a cost-effective and efficient adsorbent to control the release of Co(II) ions in industrial wastewater.

#2799 Myoglobin removal by hemadsorption: ex-vivo adsorption kinetics

Abstract Background and Aims Myoglobin, due to its molecular weight of 17 kDa and a Einstein-Stoke radius greater than expected, is classed as a middle molecular weight uremic toxin and presents a two-compartment model of distribution in the body. Rhabdomyolysis is a condition in which muscle cell content including myoglobin, are released into blood circulation due to severe injury to the muscle. Circulating myoglobin induces renal injury with several mechanisms: reduced concentration of nitric oxide in medullary renal arterioles, production of free radicals with oxidative stress, tubular necrosis as a consequence of tubular obstruction by myoglobin and cellular debris. A possible therapeutic option is the use of High Cut-off membranes but with the risk of significant loss of albumin and other proteins. The use of adsorption can overcome these limitations. The aim of our study is to assess the adsorption of myoglobin with neutral microporous styrene-divinylbenzene copolymer sorbent (e.g., HA330/380, Jafron Biomedical CO, Lts, Zhuhai City, China). Method Using a downscaled module of HA380 Cartridge, we set up an ex-vivo circulation experiment in which 1 liter of plasma containing 0.1 mg of myoglobin was pumped through the cartridge. We collected samples (3 mL) at different timepoints to measure Myoglobin concentration. We calculated the removal ratio (RR) and mass adsorbed at a given timepoints. Results Initial myoglobin concentration was 99.3 ng/ml. Final myoglobin concentration after 4 hours of experiment was 30.6 ng/ml. Removal Ratio at 4 hour was 69 % and mass adsorption of 0.068 mg of myoglobin. Conclusion To our knowledge, this is the first experiment that assessed the adsorption capacity of polystyrene-divinylbenzene sorbent. Our study, demonstrated high adsorption capacity in the first 4 hours of treatment therefore, confirming the possibility to use adsorption as an effective treatment option in rhabdomyolysis and avoiding complications associated to current dialytic treatment.

Molecular imprinting technology for next-generation water treatment via photocatalysis and selective pollutant adsorption

With the growth of industry and agriculture, contaminants such as pharmaceuticals, pesticides, phenolic residues, heavy metals, among others, have been caused serious pollution of water bodies and soil, so it is very urgently needed to find highly efficacious and cost-effective materials to remove these pollutants from environment. Owing to their low molecular weight, not easily degraded and long-term presence in the aquatic environment, super-stable mineralization effect, easily modifiable surfaces, and anion intercalation properties, molecular imprinted polymers (MIPs) present unique advantages in the removal of emerging pollutants. It is very critical to understand the mechanism of pharmaceuticals, pesticides, phenolic residues, dyes, and heavy metals removal by MIPs for the subsequent design of the adsorbent and photodegradation materials structure. Herein, we discuss the recent advancements in the applications of MIPs in water treatment, with a major focus on their use in adsorption and photocatalysis. The preparation methods and characterization of MIPs intended for water treatment are discussed at the beginning of this review. Then it discusses the potential of MIPs-based nanocomposites for the selective photocatalytic degradation and adsorption of a wide range of pollutants in water. Finally, a summary and the ongoing research efforts in this field is further provided.

Programmable Water Sorption through Linker Installation into a Zirconium Metal-Organic Framework.

Hydrolytically stable materials exhibiting a wide range of programmable water sorption behaviors are crucial for on-demand water sorption systems. While notable advancements in employing metal-organic frameworks (MOFs) as promising water adsorbents have been made, developing a robust yet easily tailorable MOF scaffold for specific operational conditions remains a challenge. To address this demand, we employed a topology-guided linker installation strategy using NU-600, which is a zirconium-based MOF (Zr-MOF) that contains three vacant crystallographically defined coordination sites. Through a judicious selection of three N-heterocyclic auxiliary linkers of specific lengths, we installed them into designated sites, giving rise to six new MOFs bearing different combinations of linkers in predetermined positions. The resulting MOFs, denoted as NU-606 to NU-611, demonstrate enhanced structural stability against capillary force-driven channel collapse during water desorption due to the increased connectivity of the Zr6 clusters in the resulting MOFs. Furthermore, incorporating these auxiliary linkers with various hydrophilic N sites enables the systematic modulation of the pore-filling pressure from about 55% relative humidity (RH) for the parent NU-600 down to below 40% RH. This topology-driven linker installation strategy offers precise control of water sorption properties for MOFs, highlighting a facile route to design MOF adsorbents for use in water sorption applications.

Hybrid Banana Pseudo Stem biochar- poly (N-hydroxyethylacrylamide) hydrogel and its magnetic nanocomposite for effective remediation of dye from wastewater

A hybrid hydrogel based on Banana Pseudo Stem, an agricultural waste material, has been developed as an adsorbent for use in wastewater treatment. The Biochar obtained from Banana Pseudo Stem was modified by graft copolymerization with N-hydroxyethylacrylamide (HEAAm). The graft copolymer was made by microwave irradiation of an aqueous mixture containing BPSBC, N-hydroxyethylacrylamide (HEAAm), N,N-methylenebisacrylamide (MBA), and potassium peroxodisulphate (KPS). The magnetite (Fe3O4) nanoparticles have been incorporated into the gel by in-situ diffusion of Fe2+ and Fe3+ followed by a reaction with ammonia solution. FTIR, SEM, EDS, TGA, VSM, BET, and XRD techniques were used to characterize the gel and its nanocomposite. The swelling process appeared to be a second-order kinetic process and the mechanism of water transport is found to be non-Fickian. The hybrid gel and nanocomposite were evaluated for the adsorptive removal of cationic dyes using Methylene Blue (MB) and Crystal Violet (CV) as model dyes. The adsorption capacities of the graft copolymer gel for MB and CV were 200 mg g−1 and 183 mg g−1 respectively. A considerable increase in adsorption capacities was observed in nanocomposite formation, with adsorption capacity values of 235 and 202 mg g−1 for MB and CV respectively. The pseudo-second-order kinetic model and Freundlich adsorption isotherm model provide the best fit of the dye sorption data. Thermodynamic studies revealed adsorption to be a spontaneous and endothermic process. Effective desorption under acidic conditions illustrated the possibility of reuse of the developed adsorbent materials in repeated cycles during the wastewater treatment process.

Yeast-Raised Polyamidoxime Hydrogel Prepared by Ice Crystal Dispersion for Efficient Uranium Extraction from Seawater.

Uranium extraction from seawater has attracted worldwide attention due to the massive reserves of uranium. Due to the straightforward synthesis and strong affinity toward uranyl ions (UO2 2+), the amidoxime group shows promise for use in highly efficient uranium capture. However, the low mass transfer efficiency within traditional amidoxime-based adsorbents severely limits the adsorption rate and the utilization of adsorption sites. In this work, a macroporous polyamidoxime (PAO) hydrogel is prepared by yeast-based biological foaming combined with ice crystal dispersion that effectively maintained the yeast activity. The yeast-raised PAO (Y-PAO) adsorbent has numerous bubble-like holes with an average pore diameter >100µm. These macropores connected with the intrinsic micropores of PAO to construct efficient diffusion channels for UO2 2+ provided fast mass transporting channels, leading to the sufficient exposure of hidden binding sites. The maximum adsorption capacity of Y-PAO membrane reached 10.07mg-U/g-ads, ≈1.54 times higher than that of the control sample. It took only eight days for Y-PAO to reach the saturation adsorption capacity of the control PAO (6.47mg-U/g-ads, 28 days). Meanwhile, Y-PAO possessed excellent ion selectivity, good reusability, and low cost. Overall, the Y-PAO membrane is a highly promising adsorbent for use in industrial-scale uranium extraction from seawater.

Experimental, isotherm, kinetic, and thermodynamic studies of the novel modified zeolite ZSM-5 adsorbent for use in clean fuel processing

Reducing the amount of sulfur in fuels is the simplest way to reduce the emission of sulfur oxide gases into the air. Among various desulfurization methods, adsorptive desulfurization stands out for its mild conditions and affordability. This research used ZSM-5 zeolite as a desulfurization adsorbent. However, adsorption capacity and selectivity are two major challenges that adsorptive desulfurization is facing. Introducing mesoporosity into zeolite is a potential solution. The study focused on mesoporous formation via desilication and dealumination. Desilication involved treating zeolite with 0.2 M and 0.5 M NaOH, while dealumination used 1 M HCl at 80 °C. Adsorbent properties were analyzed using XRD, BET, FT-IR, and FE-SEM. Initial findings indicated dealumination removed only extra-framework aluminum. Conversely, desilication removed silicon, producing a hierarchical structure even at reduced concentrations. Des-0.5M also exhibited the highest adsorption capacity for thiophene compared to the Parent sample, increasing from 4.5 to 11 mgS/g. Moreover, the adsorption capacity for larger sulfur molecules such as dibenzothiophene increased from 2.5 to approximately 6 mgS/g, indicating the significance of the hierarchical structure developed in the adsorbents. In summary, this study highlights the potential of mesoporous formation through desilication to enhance the adsorption capacity of ZSM-5 zeolite for the adsorptive desulfurization of fuels.

Development of a polyethyleneimine/poly(N-isopropylacrylamide) semi-IPN hydrogel for use in the temperature-swing adsorption and selective desorption of hydrophobic organic compounds

BackgroundA novel polyethyleneimine/poly(N-isopropylacrylamide) semi-interpenetrating polymer network (PEI/poly(NIPA) semi-IPN) hydrogel was developed as a high-performance adsorbent for use in purifying wastewater containing multiple organic compounds and recovering each organic compound. Thermosensitive poly(NIPA) with a lower critical solution temperature (LCST) of ∼33 °C in water can perform the temperature-swing adsorption, i.e., reversibly adsorb/desorb adsorbates as the temperature varies across the LCST owing to its hydrophilic/hydrophobic transition. In addition, PEI, which is a branched polymer with primary, secondary, and tertiary amine groups, can adsorb acidic adsorbates via acid-base interactions. Thus, the developed hydrogel can adsorb adsorbates via hydrophobic and/or acid-base interactions. MethodsThe PEI/poly(NIPA) semi-IPN hydrogel was prepared by free radical polymerization of NIPA and a cross-linking monomer in an aqueous solution dissolving PEI, and characterized as an adsorbent for hydrophobic organic compounds in aqueous media. FindingsThe removal (water purification) and mutual separation (recovery) of binary components (p-nitrophenol and 4-iodoaniline as model adsorbates) were demonstrated via adsorption at 50°C, followed by two-step desorption at 20°C in water and an aqueous HCl solution. This process was based on the presence or absence of hydrophobic and acid-base interactions.

Removal of Aromatic Amino-derivatives from Aqueous Solutions Using Polymeric Supports Functionalized with Aminophosphonated/aminoacid-phosphonated Groups

Aromatic amines are the significant compounds used as intermediates in the organic synthesis, for obtaining such as azo dyes, antioxidants, fuel additives, corrosion inhibitors, pesticides, antiseptic agents, poultry medicine, and pharmaceutical synthesis. However, the presence of aromatic amines in water, even at very low concentrations, is extremely harmful to aquatic life and human health. Pollution of natural waters by aromatic amines is a serious environmental concern. The aim of this work was to obtain new adsorbents for use in the removal of aromatic amines from aqueous solutions. Styrene-15%divinylbenzene copolymers grafted with aminophosphonate groups (code: AP-S15%DVB) and amino acid-phosphonate groups (code: AM-S15%DVB) were used for the removal of pollutants such as: aniline, 2-methyl-aniline and 4-methyl-aniline. The adsorption capacity and the adsorption kinetic using the pseudo-first order and pseudo-second order equations were examined. From a kinetic point of view, it was established that the adsorption of the studied amino derivatives on the used adsorbents took place according to the pseudo-second order model. It was found that the adsorption rate constant increased with the increase of temperature, so the speed of the adsorption process increased. The obtained results confirm that the polymer adsorbents studied can be successfully used for the removal of aromatic amino derivatives from aqueous solutions for the purpose of wastewater treatment.

Micropore system properties significantly influence the Na-type zeolite adsorption of the carbon disulfide impurity in mimetic coke oven gas

The experiments of the adsorption removal of CS2 impurity from a mimetic coke oven gas were performed by using a series of Na-type zeolites as adsorbents. Combining with the diffusion & simulation calculations and several characterizations, it's found both the development degree and the diffusion ability of microporous systems significantly influence the adsorption performance of these Na-type zeolites on which the physical absorption was predominant for CS2 molecules. Firstly, compared with NaZSM-5 or NaSAPO-34, the NaY with FAU-type framework exhibited a much higher breakthrough adsorption capacity, primarily due to its much higher microporous surface area & volume and larger-size channels, which ensured a broader adsorption space, a high-efficiency molecule-diffusion and a high adsorption utilization of micropores. Secondly, alkali-treatment introduced some mesopores into NaZSM-5 crystals but also resulted in a declined integrity of microporous structure, causing an obvious decline of adsorption performance. Thirdly, the nano-crystal NaZSM-5 or NaY exhibited a much higher breakthrough adsorption capacity than that of the corresponding micron-crystal zeolite, primarily attributed to both the increased microporous surface area & volume and the shortened micropore diffusion-path length of the former. In addition, a breakthrough adsorption capacity of up to 0.251 g/g was obtained in the first adsorption use of a nano-NaY-0.909 sample at 298 K, and it's 0.229 g/g in even the sixteenth time of operation (by then, total adsorption service hours were 80.58 h). Our work may provide an important reference for developing high-performance adsorbents for removing gaseous CS2 impurity in coke oven gas.

Dual chemifunctional tin(IV) oxide/nanoperforated graphene interlayer as a polysulfide adsorbent for use in high-performance lithium–sulfur batteries

The development of Li–S batteries is limited by their levels of rapid capacity decay owing to polysulfide dissolution and diffusion in organic electrolytes. We addressed this critical issue by fabricating a dual chemifunctional interlayer comprising SnO2 nanoparticles and nanoperforated graphene (NPG) that could function as a polysulfide adsorbent. The synergistic effects of SnO2 and the high-density functional groups of NPG on polysulfide capture were conceptually confirmed. NPG not only supported the adsorption of Li polysulfides but also provided pathways for simple Li-ion motion within the SnO2/NPG interlayer. A cell assembled with the SnO2/NPG interlayer displayed a high rate capability and initial discharge capacity and good reversible capacity. The excellent high-rate cycling performance of the cathode could mainly be attributed to the strong chemical bonds formed between SnO2/NPG and the polysulfides, rapid electron transfer, and optimized ion diffusion pathways derived from the well-organized structure of the composite. Synthesizing dual chemifunctional interlayers using a composite of metal oxides and NPG may lead to the development of advanced Li–S batteries with numerous practical applications in the near future.

Preparation of Open-Cell Long-Chain Branched Polypropylene Foams for Oil Absorption.

This study aimed to prepare open-cell foams using a blend of long-chain branched polypropylene and polyolefin elastomer (LCBPP/POE) for the production of reusable oil absorbents. The supercritical CO2 foaming process was conducted using a two-step batch rapid depressurization method. This unique two-step foaming approach significantly expanded the temperature and pressure windows, resulting in more uniform cells with smaller sizes, ultimately leading to higher expansion ratios and an increased open cell content. The foaming process was optimized by adjusting parameters, such as the LCBPP/POE ratio, foaming temperature, and foaming pressure, reaching a maximum open cell content of 97.6% and a maximum expansion ratio of 48. The influence of polypropylene (PP) crystallization was investigated with the aid of scanning electron microscopy and differential scanning calorimetry. Furthermore, the hydrophobic and lipophilic characteristics of the LCBPP/POE open-cell foam were determined via contact angle measurements and oil/water separation tests. Oil absorption tests revealed that the blended LCBPP/POE foam has a higher oil absorption capacity than that of the pure LCBPP foam. The cyclic oil absorption tests demonstrated the outstanding ductility and recoverability of the LCBPP/POE open-cell foam in comparison to those of the pure LCBPP foam. Over 10 cycles, the LCBPP/POE foam maintained a substantial adsorption capacity, retaining 99.3% of its initial oil absorption capacity. With its notable features, including a high open cell content, excellent hydrophobic and lipophilic characteristics, superior oil absorption capacity, impressive cyclic oil absorption performance, and robust reusability, LCBPP/POE open-cell foams exhibit significant promise as potential oil adsorbents for use in oil spill cleanup applications.

Synthesis and characterization of new composite sponge combining of metal-organic framework and chitosan for the elimination of Pb(II), Cu(II) and Cd(II) ions from aqueous solutions: Batch adsorption and optimization using Box-Behnken design

By using a one-step hydrothermal process in an acidic environment, an unique Ag-MOF/chitosan composite sponge (Ag-MOF/CSC composite sponge) was effectively created. Chitosan synthesis has been studied for more than half a century, but its Use for adsorption of heavy metals (HM) is presently being researched. As Particularly with regard to adsorbents constructed of metal organic framework, to increase an adsorbent material's adsorption capacity, its composition is commonly changed. Pb(II), Cu(II), and Cd(II) adsorption and elimination were examined in this study in relation to the composite Ag-MOF/CSC sponge. Following thorough analysis including measurements of the surface area using Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and SEM and Fourier transform infrared spectroscopy (FTIR) (BET).The Ag-MOF/CSC composite sponge exhibits an impressive large surface area of 1496.58 square meters per gram, besides having the best capacity for adsorption (qmax) for various ions: 1.80, 1.49 and 1.72 mmol per gram for Pb(II), Cu(II) and Cd(II), respectively. Consider the factors that influence the adsorption characteristics, such as temperature, pH, metal concentration, and adsorbent dosage. The kinetic isotherm and the adsorption isotherm were fitted using the pseudo-second-order equation and the Langmuir equation, respectively. It was shown that the adsorption process was endothermic and spontaneous in accordance with adsorption thermodynamics. With rise in temperature, more metal were absorbed. With good efficiency, no change in chemical composition, and similar XRD and XPS data before and after reuse, the Ag-MOF/CSC composite sponge was repurposed six times. Investigate the mechanism of interaction between the heavy metals and the Ag-MOF/CSC composite sponge. Utilizing Box-Behnken design, the adsorption outcomes were optimized (BBD).

Field assessment of coconut-based activated carbon systems for the treatment of herbicide contamination

Once released into the environment, herbicides can move through soil or surface water to streams and groundwater. Filters containing adsorbent media placed in fields may be an effective solution to herbicide loss in the environment. However, to date, no study has investigated the use of adsorbent materials in intervention systems at field-scale, nor has any study investigated their optimal configuration. Therefore, the aim of this paper was to examine the efficacy of low-cost, coconut-based activated carbon (CAC) intervention systems, placed in streams and tributaries, for herbicide removal. Two configurations of interventions were investigated in two agricultural catchments and one urban area in Ireland: (1) filter bags and (2) filter bags fitted into polyethylene pipes. Herbicide sampling was conducted using Chemcatcher® passive sampling devices in order to identify trends in herbicide exceedances at the sites, and to quantifiably assess, compare, and contrast the efficiency of the two intervention configurations. While the Chemcatcher® passive sampling devices are capable of analysing eighteen different acid herbicides, only six different acid herbicides (2,4-D, clopyralid, fluroxypyr, MCPA, mecoprop and triclopyr) were ever detected within the three catchment areas, which were also the only acid herbicides used therein. The CAC was capable of complete herbicide removal, when the water flow was slow (0.5–1 m3 s−1), and the interventions spanned the width and depth of the waterway. Overall, the reduction in herbicide concentrations was better for the filter pipes than for the filter bags, with a 48% reduction in detections and a 37% reduction in exceedances across all the sampling sites for the filter pipe interventions compared to a 13% reduction in the number of detections and a 24% reduction in exceedances across all sampling sites for the filter bag interventions (p < 0.05). This study demonstrates, for the first time, that CAC may be an effective in situ remediation strategy to manage herbicide exceedances close to the source, thereby reducing the impact on environmental and public health.

Evaluation of Pb2+ ion adsorption by roasted and grounded barley (Hordeum vulgare L.) waste

This work was carried out with the objective of studying the process of adsorption of Pb2+ ions by barley dust, Hordeum vulgare L. The adsorbent material was prepared by boiling in water with consequent sedimentation, drying, grinding and sieving. Kinetic, isothermal and thermodynamic studies were carried out in the adsorption processes. Factors such as contact time (1–128 min), initial concentration (20–400 mg.L-1) and temperature (288–298, 308 and 318 K) were considered. Mathematical models were applied and satisfactorily demonstrated the adsorptive process. The pseudo-first order models, pseudo-second order models Elovich and Boyd showed that equilibrium was reached within the first 40 min, with the pseudo-second order model as the most suitable to describe the process, as well as adsorption by external diffusion was demonstrated from the model of Boyd. The adsorption isotherm was evaluated using the Langmuir, Freundlich and Temkin models, demonstrating great applicability to the adsorptive process. The maximum adsorption capacity obtained in the Langmuir model was in the order of 25.76 mg.g−1. The Freundlich model indicated that the process is favorable. The thermodynamic parameters were calculated, demonstrating that the adsorption is endothermic and favorable. Therefore, the results obtained showed that the waste of roasted and ground barley powder can be used as an alternative, viable and low-cost adsorbent for use in processes aimed at decontaminating effluents containing Pb2+ ions.

Reducing the negative impact of accidents associated with the release of dangerous substances to environment.

The article is concerned with an evaluation of the current state of emergency readiness of industrial companies in the event of dangerous substance leakage and with a presentation of textile sorbents used for the purposes of capturing an escaped substance. A part of the article is concerned with the experimental designation of sorption capacity of hydrophobic, chemical, and universal sorption mats for chosen polar (water and alcohol) and non-polar (oil and gasoline) liquids. Experiments were realized according to Standard Test Method for Sorbent Performance of Adsorbents for use on Crude Oil and Related Spills, American Society for Testing and Materials (ASTM F726-17), type I. and Test methods for non-woven fabrics, European Union International Organization for Standardization (EN ISO 9073-6:2004). The aim of the article is an experimental designation of sorption capacity of textile sorption mats using two different methods, a comparison of the acquired results and a comparison of the acquired data with the data given by the manufacturer. Textile sorbents, which can, owing to their sorption ability, allow the elimination or mitigation of a negative impact of a possible accident in the company connected with an escape of a liquid dangerous substance were tested and compared with the established values. Based on the obtained results it is possible to state that sorption capacities of the chemical and universal mat for the substrate water are equal and consistent with the data given by the manufacturer. Textile sorption mats also have a comparable sorption capacity. The sorption capacity on the substrate gasoline is the same in all textile sorbents. The adsorption capacity per unit mass all type's sorbents was similar for non-polar liquids (gasoline was values from 6.41 to 6.57 and oil was values from 9.54 to 10.24). The acquired results confirmed the universality of textile sorption mats for gasoline. Sorption capacities of the chemical and universal mat for the substrate water are equal and match the data given by the manufacturer. Textile sorption mats have a maximum sorption output up to 60 s, afterwards the sorption capacity values remain unchanged.