Use Of Adsorbents Research Articles

Removal of Heavy Metal from Wastewater using Water Chestnut Shell as an Adsorbent

The contamination of water resources as a result of industrial activity is on the rise and is a global concern. The heavy metals found in wastewater are long lasting and non-biodegradable. Contamination with heavy metals over acceptable limits could result in major health problems. Chemical precipitation, chemical oxidation, ion exchange, membrane separation, reverse osmosis, electrodialysis, adsorption, and other technologies are used to lessen the influence of heavy metals on water bodies. Some procedures are extremely costly, energy-intensive, and frequently result in the production of harmful by-products. The use of adsorption as a cost-effective approach for removing heavy metals from industrial wastewater has been examined. The usage of Trapa bispinosa peels/shell as a low-cost adsorbent for wastewater treatment is discussed in this paper. Chemical activation was used to make activated carbons from Trapa bispinosa peels and shells. Activated carbons made from a combination of Trapa bispinosa peels/shells and Phosphoric acid with varying impregnation ratios. The results revealed that the activating temperature for the production of Trapa bispinosa-derived activated carbon is 500℃ (AC). CHNS, X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy were used to analyze the activated carbons.

Ecological aspects of sorbents use to improve the efficiency of bioremediation on oil-contaminated lands

Nowadays, polluted soils are one of the primary environmental problems. Due to a large number of oil-contaminated lands, new methods are being developed more and more actively, as well as a combination of various existing methods for disposing of oil spills. In this paper, bioremediation with the use of adsorption is considered to reduce toxicity and accelerate the processes of microbial destruction of hydrocarbons. There is a large selection of sorbents based on carbon, mineral, and natural materials. The effectiveness of a particular sorbent will vary depending on the application region, weather and climate conditions, soil type, and the type and properties of the oil. In this work, peat was tested as an organic sorbent (S1), vermiculite as a mineral sorbent (S2), and sorbent based on carbon (S3). The sorbents were added to the soils contaminated by oil, evaluating the pH, humidity, and phytotoxicity of the soils. The results showed that the soils treated with sorbents maintained the neutral pH, increased the humidity, and decreased the phytotoxicity of the soil. The sorbent efficiency was S3> S2> S1.

Optimising Adsorptive Stripping Voltammetry: Strategies and Limitations

AbstractThe widely employed electroanalytical technique of adsorptive stripping voltammetry (AdsSV) is critically assessed and evaluated at a wide and diverse range of unmodified and nano‐particle modified carbon electrodes using the analyte fipronil as a paradigmatic case. The generic electroanalytical performances of the nano‐particle modified electrodes are investigated and compared with the unmodified electrodes revealing similar LOD values and pointing to intrinsic limitations of AdsSV arising from the non‐independence of the Faradaic and capacitive signals during the stripping step. Methods for facilitating the adsorption or using different waveforms that may offer a more favourable limit of detection (LOD) at the nano‐particle modified electrodes are suggested and assessed, specifically the use of adsorption onto particles prior to their use for modifying electrodes and also the recently introduced method of semi‐circular voltammetry.

Removal efficiency of As(III) from aqueous solutions using natural and Fe(III) modified bentonites

ABSTRACT Contamination of water with arsenic is a major global health problem. The use of adsorbent materials for the removal of As from aqueous systems is a plausible solution to this problem. In this work, the use of commercial bentonites (purified and modified with iron (III)) for the removal of As from water was studied. The samples were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier Transformed Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and nitrogen adsorption/desorption isotherms to determine their physicochemical properties. The arsenic removal capacities of adsorbent materials were studied from 1 mg/L solutions of As (III) using the colorimetric technique of molybdenum blue. High adsorption capacity (0.33 mg/g) of As (III) was obtained in aqueous systems after 1 h of treatment with unmodified bentonite. The incorporation of iron improved the removal performance in short times. The obtained results could be the starting point for the development of a low-cost filtration system that contributes to solve the problem of arsenic in water.

Penerapan kolom adsorpsi seri dengan adsorben sekam padi pada penyisihan logam seng (Zn) dari air tanah

To increase the performance of continuous adsorption with rice husks as adsorbent in Zn removal from groundwater, a series of fixed bed column was applied. The experiments were carried out at the acrylic columns having diameter of 7 cm, column height of 19.5 cm, bed height of 13.5 cm and flow rate of 2 gpm/ft2 (310 mL/minute) for 540 minutes. The number of columns used were 3 columns arranged in series and the rice husk used were in their original size (1-2 mm). The influent concentration of Zn metal was 7.62 mg/L. The results showed that the use of column adsorption in series increased the removal efficiency of Zn by rice husks, from 33.21% using 1 column to 51.70% with 3 columns. The adsorption capacity of Zn obtained when using 3 columns in series was 3.542 mg/g. In addition, the use of adsorption columns in series can also prolong the saturation of the adsorbent, thereby extending its service life. The overall research results demonstrated that column the adsorption in series with rice husk as an adsorbent has the potential to be applied to remove heavy metals from groundwater.

A water-stable functionalized NiCo-LDH/MOF nanocomposite: green synthesis, characterization, and its environmental application for heavy metals adsorption

Removal of toxic heavy metals from aquatic environments has become a major concern due to environmental problems and the potential hazards and risks posed by them. Nowadays, the adsorption method as one of the most effective methods of removing pollutants has attracted increasing attention among chemists and environmental researchers. However, one of the challenges is to design and develop more effective adsorbents as well as to prepare them via greener and safer approaches. In line with these goals, a functionalized Ni50Co50-layered double hydroxide/UiO-66-(Zr)-(COOH)2 nanocomposite (LDH/MOF NC) was prepared via a facile and “green“ synthesis protocol and used as an effective adsorbent for removal of mercury and nickel cations from aqueous media. UiO-66-(Zr)-(COOH)2 nanoparticles were in situ grown homogeneously over the surface of the functionalized two-dimensional ultrathin Ni50Co50-LDH sheets. A green organic-solvent-free route was used to prepare the LDH/MOF NC in which the water is used as a green solvent. The adsorption performance of LDH/MOF NC for removal of Hg(II) and Ni(II) cations was studied and the influence of some experimental factors, such as solution pH, initial metal concentration, and contact time, on the adsorption process were investigated. The theoretical maximum adsorption capacities based on the Langmuir isotherm were found to be 509.8 mg g−1 and 441.0 mg g−1 for Hg(II) and Ni(II), respectively, under constant conditions. We believe that the facile and “green” synthesis method used in this work can be a starting point for the fabrication and development of similar composite materials for future works, especially for use in adsorption, extraction, catalysis, and drug delivery applications.

Effect of Contact Time Adsorption of Rhodamine B, Methyl Orange and Methylene Blue Colours on Langsat Shell with Batch Methods

This study aims to determine the uptake capacity of langsat (Lansium domesticum) skin on the adsorption of dyes along with the contact time. Textile dyes are dyes which is harmful for the environment and living things. This textile industry waste can cause a decrease in water quality. When this carcinogenic dye enters the human body, it can lead to cancer. The process of these dyes adsorption use langsat skin samples. The components of langsat skin that can adsorb dyes are triterpenoids, saponins and flavonoids. This study uses a batch method by treating the contact time variations of several dyes. The results reveal that the biomass adsorption on rhodamine B, methyl orange, and methylene blue dyes were 11,578 mg/g, 3.8425 mg/g, 36,735 mg/g respectively and with optimum contact time of 60, 90 and 150 minutes, respectively.

Controlling the adsorption of mineral porous particles by chelation

Problem formulating. To increase the sorption capacity of calcium carbonate microparticles used as core for the development of targeted drug delivery, EDTA chelation of calcium ions was used to form a developed active surface of the particles. Goal. Is in modification of the surface of micron and submicron calcium carbonate vaterite particles using EDTA chelation of calcium ions and studying the effect of particle processing on their sorption capacity. Result. It was shown using scanning electron microscopy that EDTA treatment of the CaCO3 surface leads to an increase on the surface roughness of the particles, as well as an increase on their sorption capacity according to spectrophotometric data. Practical meaning. Use of adsorption to encapsulate the active substance inside the carriers. It is shown that an increase in the sorption capacity of particles leads to an increase in the amount of a substance inside its volume.

Synthesis, Structure and Properties of an Extra‐Large‐Pore Aluminosilicate Zeolite NUD‐6

Pure silica zeolites possessing uniform micropores, large surface area and high thermal and chemical stability have been widely studied and used in the fields of fine chemicals and oil industry. The incorporation of aluminium into the framework of silica zeolites changes their properties, making them more industrially useful as adsorbents and catalysts. Herein, we report the synthesis and characterization of an extra-large-pore aluminosilicate zeolite NUD-6 with a 16-membered-ring pore channel. Aluminium was directly incorporated into the zeolite NUD-6 framework, as confirmed by 27 Al MAS NMR studies and ammonia temperature-programmed desorption probes. Al-NUD-6 was not stable when heated at 550 °C to remove the organic templates. However, the organic templates in Al-NUD-6 could be removed by oxidation in nitric acid at room temperature. The obtained Al-NUD-6H retained the crystalline structure and possessed both micropores and mesopores despite the occurrence of severe structural distortions due to the presence of the corner-sharing Q3 Si2 O7 units. The incorporation of aluminium resulted in both medium and strong acid sites in Al-NUD-6H, and could facilitate its use in adsorption and catalysis.

Easy removal of nitrate and phosphate anions from water by low cost chitosan and activated charcoal

AbstractPresence of nitrate and phosphate ions is difficult to remove from the lakes, as they are highly soluble in water. A way of chemical method adopted to remove these ions from the drinking water using the simple method use of naturally abundant chitosan with charcoal. Adsorption of nitrate and phosphate anions from aqueous solution (water/waste water) on both the chitosan and activated charcoal was investigated. In batch mode adsorption study leads to developing efficient low-cost removal method is important to protect the aquatic environment from the high concentration of nitrate and phosphate anions intake as well as adverse effects on human health. The modified chitosan microspheres had a laudable performance for nitrate and phosphate adsorption Use of this material as an adsorbent is a cheaper and biocompatible method. A systematic study of the adsorption of nitrate and phosphate anions on chitosan and activated charcoal was performed by varying the pH, the initial concentration, contact time, and adsorbent dosage. The results demonstrate that the adsorption process was followed adsorption kinetics of both first and second order kinetics when we use of the chitosan and activated charcoal and chitosan is promising for treating water that is contaminated with nitrate and phosphate anions.

Removal of methylene blue from aqueous solutions using a solid residue of the apple juice industry: Full factorial design, equilibrium, thermodynamics and kinetics aspects

The use of adsorbent materials derived from agro-industrial residues represents a simple, easy and low-cost process for the removal of dyes from aqueous solutions. In this context, this study aimed to evaluate the use of a solid residue from the apple juice industry in the removal of methylene blue (MB) dye. Several different analytical techniques, including elemental analysis, Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance, nitrogen adsorption/desorption and determination of pH at zero-point charge, were used to investigate the physico-chemical properties of the apple pomace. Conventional bath experiments were carried out by simultaneously optimizing five variables (initial MB concentration, amount of adsorbent, pH, stirring frequency and temperature) using a full 2k factorial design with central point. In general, the characterization analyses evidenced the presence of several types of oxygenated functional groups in the adsorbent chemical structure and a favorable morphology for dye removal. Furthermore, the initial MB concentration, the amount of adsorbent and the pH of the medium had the strongest effect on the response variables, including their interactions and quadratic terms. In terms of equilibrium, it was found that the Langmuir model gave a good fit to the data, while the thermodynamic parameters indicated that the process was spontaneous and exothermic in nature. Moreover, kinetic studies revealed that the MB removal rate followed a pseudo-second-order model, suggesting an adsorption controlled by either diffusion on the stagnant film covering the adsorbent particles or intraparticle diffusion. Finally, the data acquired in this study also emphasized the interest to use materials derived from agro-industrial residues as potential adsorbents in the light of its properties for the removal of basic dyes, including MB.

Electricity Generation Using a Hybridized Zeolite Adsorption Heat Pump and Heat Engine

The use of adsorption in Thermal Energy Storage has gained considerable research interest of late. Some applications have focused on the use of TES for transformation of low temperature heat in applications such as cooling and heating. Zeolite and water have been studied as suitable materials. Their characteristics as environmentally friendly materials and high affinity makes them conspicuous. The unique properties of zeolites to hold adsorbed water/heat with very minimal loss is also significant. With the aid of a dynamo, a Stirling engine as heat engine and the adsorption energy storage system serving as heat pump was used to generate electricity. The relationship between electricity generation and temperature was investigated. The obtained average temperature and pressure of the zeolite - water adsorption heat pump was also compared with the basic adsorption cycle.

Reverse-phase/phenylboronic-acid-type magnetic microspheres to eliminate the matrix effects in amatoxin and phallotoxin determination via ultrahigh-performance liquid chromatography-tandem mass spectrometry.

In this study, we present the preparation of a new reverse-phase/phenylboronic-acid (RP/PBA)-type mixed-mode magnetic solid-phase extraction (MSPE) adsorbent for use in the cleanup of amatoxin- and phallotoxin-containing samples intended for ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. Further, the RP/PBA magnetic microspheres have phenyl and phenylboronic acid groups on their surfaces that selectively adsorb amatoxins and phallotoxins through hydrophobic, π-π, and boronate affinity, significantly reducing matrix effects in UPLC-MS/MS analysis. After systematic optimization, all the standard calibration curves expressed satisfactory linearity (r>0.9930), limits of detection (0.3μg/kg), and recovery (97.6%-114.2%). Compared with other reported methods, this method also has the advantages of simple, fast, and efficient operation using relatively small amounts of the MSPE adsorbent. Furthermore, the method was successfully applied in a poisoning incident caused by Lepiota brunneoincarnata Chodat & C. Martín ingestion.

TEMPO-oxidized cellulose nanofiber based polymeric adsorbent for use in iron removal

Cellulose nanofibrils (CNFs), as one of the most abundant renewable nanomaterials, has garnered interest in numerous fields owing to its many any advantages such as good mechanical properties, high surface area and surface tunability. Recently, CNFs have been shown to be a valuable candidate in water and soil treatment. In this study, adsorption of Fe(II) cations onto poly(2-hydroxy ethyl methacrylate-glycidyl methacrylate) cryogels was improved by addition of TEMPO-oxidized cellulose nanofibers (CNF). Characterization of CNF modified polymeric structures was performed using scanning electron microscopy. The effects of varying pH, initial Fe(II) concentration, and time were investigated during the study and a comparison was made to Fe(III) adsorption. Kinetic calculations were performed using Langmuir, Freundlich and Redlich–Peterson adsorption models.to understand the binding of Fe(II) cations onto the composite cryogel.

Tunable Effect of the Calcination of the Silanol Groups of KIT-6 and SBA-15 Mesoporous Materials

The calcination process is a crucial step during SBA-15 and KIT-6 synthesis. It is used to completely remove the organic template and condense silanol groups, and it allows the determination of the textural and physical properties of these materials, depending on the adopted conditions. Moreover, calcination influences the number of silanols available on the surface of the material. The concentration of silanols is important if these materials were synthesized for use in adsorption or functionalization. To understand and optimize the silanol groups of SBA-15 and KIT-6, in this study, the temperature and time calcination parameters were varied. The experiments were performed at 300, 400, and 500 °C for 300, 400, and 500 min. The results show that the ideal temperature to preserve the silanol groups is 300 °C, but to optimize the textural properties, it is better to calcine these molecular sieves at 400 °C. A calcination for 10 h did not give better results than a calcination for 5 h, demonstrating that the former duration is excessive for use.

Non-Isothermal Kinetics of Kr Adsorption by Nanoporous γ-Mg(BH4)2 from in Situ Synchrotron Powder Diffraction.

Crystalline materials with pore dimensions comparable to the kinetic diameters of the guest molecules are attractive for their potential use in adsorption and separation applications. The nanoporous γ-Mg(BH4)2 features one-dimensional channels matching this criterion for Kr uptake, which has been probed using synchrotron powder diffraction at various pressures and temperatures. It results in two coexisting crystalline phases with the limiting composition Mg(BH4)2·0.66Kr expecting the highest Kr content (50.7 wt % in the crystalline phase) reported for porous materials. Quasi-equilibrium isobars built from Rietveld refinements of Kr site occupancies were rationalized with a noncooperative lattice gas model, yielding the values of the thermodynamic parameters. The latter were independently confirmed from Kr fluorescence. We have also parameterized the pronounced kinetic hysteresis with a modified mean-field model adopted for the Arrhenius kinetics.

Optimization of dosing and mixing time through fabrication of high internal phase emulsion (HIPE) polymerization based adsorbents for use in purification of oil in water contaminated wastewater

AbstractDisposal of oil‐contaminated wastewater is associated with serious environmental problems since it is drained in seawater or into the ground. These routes of disposal can dangerously affect the lives of both humans and aqua creatures. Therefore, this research study introduces the recovery of petroleum wastewater through the usage of polystyrene‐based adsorbents. High internal phase emulsion polymerization was the used methodology to provide the introduced structures where new approaches have been presented. Unlike the common, the influence of the fabrication parameters of polymeric adsorbents on the oil removal has been investigated. Particularly, different dosing and mixing times were utilized during the preparation stage. Their effect on the polymers surface properties and molecular weights were traced. The obtained adsorbents were subjected to the oil removal stage where optimization of synthesis conditions was taken place. Nearly 92% of the oil content (80 ppm) in the wastewater was removed using the optimized adsorbent. This adsorbent showed surface area of 28.8 m2/g and molecular weight equal 279,970 g/mol. It was acquired by applying 20 min as a dosing time and reaction time of 120 min.

Production of biochar for potential catalytic and energy applications via microwave vacuum pyrolysis conversion of cassava stem

Cassava stem waste is abundantly available after starch extraction, hence posing disposal problem and potential risk to environmental pollution. Alternative ways are needed to dispose the waste instead of landfilling and open burning. Microwave vacuum pyrolysis was examined as an alternative method to convert the cassava stem waste into biochar. The cassava stem was first characterized by several analyses followed by conversion into biochar using microwave vacuum pyrolysis over different microwave power. The cassava stem contained high contents of carbon (49.5 wt%) and considerable amount of fixed carbon (27 wt%), indicating its suitability to be used as pyrolysis feedstock. The biochar yield from microwave power of 550 W, 650 W and 750 W were 77%, 73% and 70% respectively. The surface morphology of biochar shows that it consists abundant pores on the surface, suggesting its suitability to be used as catalyst support for energy application, and also as adsorbent for use in adsorption-related process such as dye and heavy metal removal in wastewater treatment or nutrient retention in crops cultivation. The calorific value of the biochar ranged from 19.24 to 20.55 MJ kg−1, showing high energy content for potential use as solid fuel. Our results show that cassava stem can be transformed into biochar for useful energy applications rather than burned as low-grade fuel in boiler or disposed by landfilling.

Use of adsorption for pesticides removal from drinking water sources

Pesticides can get in drinking water sources above all by means of agricultural activities, and they can negatively affect not only the environment but also our health. Adsorption is one of the water treatment processes used for pesticide removal from water. Our laboratory trial studying removal of pesticides from raw water used the sorption process on two selected sorbents. The laboratory experiment was performed at the Institute of Municipal Water Management, Faculty of Civil Engineering, Brno University of Technology. Charcoal was one of the sorbents, used in the form of Filtrasorb F100. The other sorbent was Bayoxide E33, selected due to its favourable results in removal of metals from water. The measured values suggest that Filtrasorb F100 reduced concentrations of most pesticides down to the lower limit of measurability. Only pesticide metazachlor ESA showed continuous increase of concentration in the course of the filtration. Bayoxide E33 was unable to remove pesticides. Most pesticides were desorbed by the material after a time, only in the case of two pesticides (atrazin-2-hydroxy and terbuthylazin-desethyl-2-hydroxy) concentrations were reduced down to the limit of measurability.

Clean-up of crude oil-contaminated soils: bioremediation option

As we advance towards “a non-toxic environment”, there is increased action in the soil, surface, and groundwater remediation activities in response to the world’s environmental quality objectives. Crude oil is a pollutant whose entrance into the soil, surface, and groundwater environments has elicited profound negative impacts as harbinger of soil, water, and air pollution. The effects of oil spillage in the environments are unprecedented and cannot be ignored. It is necessary to decontaminate the polluted ecosystem after a spill since they are potent immunotoxicants and carcinogens, which can cause kidney diseases, cancer, and liver damage. Bioremediation, a technology that exploits the various capabilities of microorganisms to degrade or convert organic pollutants to innocuous products through mineralisation, has become the process of choice in the quest to remove soil contaminants. The bioremediation technology is deemed efficient, is low cost, does not require any technical skills to function, and mostly does not impact the ecosystem negatively. Although the efficacy of the bioremediation treatment is inhibited by the properties of the pollutants, the soil matrix, and the ecological factors, it remains the process of choice for most environmentalist. This article reviews the bioremediation process, highlighting the use of adsorption and photocatalysis as the most popular strategies applied in the reduction of pollutants in contaminated water bodies.