Low-cost Adsorbent For Removal Research Articles

Biosorptive removal of lead by lentil husk

Lentil husk an agricultural waste was found to be a promising low cost adsorbent for removal of lead and showed maximum adsorption potential among all other agricultural wastes tested. Different physico-chemical parameters were found to influence the adsorption process. Lead uptake capacity of lentil husk (qmax) was 81.43mgg−1 at optimized pH (5.0) and temperature (30°C) with an initial metal ion concentration of 250mgL−1. Adsorption process was well interpreted by Langmuir isotherm model. Kinetic study showed sorption was very fast at initial stage and equilibrium was reached within 60min following pseudo second order rate model. Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX) and Fourier transform infrared spectroscopy (FTIR) further confirmed the sorption of lead. Chemical modification of functional groups revealed both hydroxyl and carboxyl groups played crucial role in binding process. The concerned biomass was capable of removing lead from actual industrial effluent.

Novel use of riche husk Carbon (A Natural Silica-Carbon Matrix) For Fluoride Removal From Aqueous Solution

Utilization of one waste material to control pollution caused by another is of high significance in the remediation of environmental problems. Rice husk, an abundantly available agricultural waste, can be used to as a low cost adsorbent for removal of fluoride from contaminated water. Rice Husk Carbon (RHC) was prepared at temperature 500 0 C and characterized by SEM, XRD and FTIR study. Experiment of fluoride removal was studied by column adsorption experiment with respect to flow rate, pH, initial concentration and column depth were carried out.RHC exhibited almost scavenging capacity at various bed depth with a flow rate 4.37 ml/min. Maximum adsorption capacity of RHC was recorded 0.429 mg/g. The adsorption studies were simulated using Thomas and Bed depth service time model. Both the models consistently predict its characteristic parameters and describe the breakthrough profiles in the whole range of sorption process.

U(VI) ion adsorption thermodynamics and kinetics from aqueous solution onto raw sodium feldspar and acid-activated sodium feldspar

The raw sodium feldspar (RSF) is activated with the concentrated sulfuric acid solution and the acid activated sodium feldspar (AASF) is obtained. The results obtained from the mercury intrusion method show that the acidification can increase the porosity and the specific surface area. The effects of the initial pH, contact time and ambient temperature on the adsorption of U(VI) ions are investigated in a batch process. The adsorption efficiency amounts to the highest at pH 6 and the adsorption equilibrium is reached in 600 min. The pseudo-second-order model is found to be more suitable for the adsorption process than the pseudo-first-order model and intra-particle model, indicating that the chemical adsorption is the predominant step for the adsorption process. Langmuir model is found to describe the adsorption process better than Freundlich model. This proves that the main form of U(VI) ions attached to RSF and AASF is the monolayer coverage. The thermodynamic parameters prove that the adsorption process is a spontaneous endothermic one. It was also found that acid activated treatment can help increase the adsorption rate and capacity. The results show that RSF and AASF can be used as a novel low cost adsorbent for removal of U(VI) ions from the low concentration aqueous solution.

Spectroscopic and computational evaluation of cadmium adsorption using activated carbon produced from rubber tires

The aim of this work was to investigate the utilization of waste tire carbons as a low cost adsorbent for removal of cadmium (II) ion from aqueous solution with density functional theory calculations to shed more light on the adsorption process. Thus, activated carbon was prepared from waste rubber tires and characterized by means of field emission scanning electron microscopy, energy-dispersive X-ray and Fourier transform infrared spectroscopies. Effect of various operating parameters like contact time, dosage, agitation speed and pH on the removal of Cd(II) from aqueous solution by the batch adsorption technique was investigated. The adsorption process was relatively fast and the equilibrium was reached after about 60min of contact. Characterization of activated carbon after adsorption was also conducted. Density functional theory (DFT) calculations were performed to estimate the binding energy of Cd2+ ions towards carboxylic acid, carbonyl and hydroxyl groups. The calculated binding energy of the adsorption process was predicted to be in the range of 190–212kcal/mol, and the Cd2+ ion tends to approach more conveniently towards the carbonyl's oxygen atom in the carboxylic acid and carbonyl groups. The developed sorbent exhibited the advantages of being inexpensive and of double benefit to the environment.

Removal of Heavy Metals in Water by Functionalized Mesoporous Silica Materials: A Review

This paper reviews the emerging applications of mesoporous silica materials to be as adsorbents for heavy metals removal from the wastewater. Functionalization of the ordered mesoporous silica with organic or hybrid function groups provides new opportunities for fine-tuning the chemical, physical and mechanical properties of these novel materials. This has led to an interest in application of these materials as effective and low-cost adsorbents for removal of heavy metals, such as Pb (II), Cu (II), Hg(II), Cr (III), Cd (II) and Ni (II).

Adsorption of As(III) and As(V) by Fe coated biochars and biochars produced from empty fruit bunch and rice husk

The study was conducted to determine the adsorption capacity of commercially produced empty fruit bunch biochar (EFBB) and a rice husk biochar (RHB) for As(III) and As(V). The effects of coating the biochars with Fe(III) on adsorption of As(III) and As(V) were also studied. Batch equilibrium adsorption was employed to determine the adsorption capacity of the biochars for As(III) and (V). The adsorption data were fitted to the Langmuir adsorption model. The maximum adsorption capacity (Qmax) of both EFBB and RHB for As(III) was higher than for As(V). The Qmax of EFBB and RHB for As(III) was 18.9mgg−1 and 19.3mgg−1, respectively. In contrast, the Qmax of EFBB and RHB for As(V) was only 5.5mgg−1 and 7.1mgg−1, respectively. Coating the EFBB and RHB with Fe(III) increased their Qmax values for both As(III) and As(V). The Qmax of Fe-coated EFBB (FC-EFBB) and Fe-coated RHB (FC-RHB) for As(III) was 31.4mgg−1 and 30.7mgg−1, respectively. The Qmax of FC-EFBB and FC-RHB for As(V) was 15.2mgg−1 and 16.0mgg−1, respectively. Although the surface area of the EFBB (1.890m2g−1) was much lower than the RHB's (25.161m2g−1), its adsorption capacity for the As was not much different than the RHB, suggesting that oxygen-containing functional groups, zeta potentials, the amounts of functional groups, O/C ratios, (O+N)/C ratios and polarity indices [(O+N)/C] were important in determining As adsorption by these biochars. The biochar surfaces were smooth before As adsorption and became coarser after As was adsorbed. The adsorption of As was confirmed by the EDS data. EFBB and RHB have potentials to be used as low cost adsorbents for removal of As(III) from waste water while FC-EFBB and FC-RH could be used for removal of both As(III) and As(V)

Optimisation of sugar cane activated carbon for arsenic(V) and arsenic(III) removal from water

This paper addresses the development of low-cost adsorbents for removal of arsenic from water in support of mitigation programmes in low and middle income countries. Activated carbon (AC) is a well established water treatment technology, but has high cost and low selectivity in respect of arsenic. AC made from agricultural by-products is a low-cost alternative to coal-based AC. In this study, the preparation parameters of sugar-cane activated carbon (SCAC) were optimised for arsenic(V) and arsenic(III) adsorption. The effect of preparation parameters on arsenic removal was investigated with a 23 factorial experiment. SCAC was characterised by the pH of zero charge, surface area, pore width distribution, particle size distribution and imaging under scanning electron microscopy. Activation temperature (AT) has a profound effect on arsenic adsorption; arsenic(V) adsorption increased from 2.8% at an AT of 873 K to 87.6% at an AT of 1,173 K. The percentage of arsenic removal from water has a strong positive correlation with surface area, and a strong negative correlation with micropore/pore volume ratio and the percentage in volume of particles with a size of 60–2,000 μm. In conclusion, this research shows that low-cost AC can be manufactured for removal of target pollutants, such as arsenic, from water.

Cationic Dye (Methylene Blue) Removal from Aqueous Solution by Montmorillonite

Color impurity in industrial effluents pose a significant risk to human health and the environment, so much effort has been expended to degrade them using various methods, including the use of clay minerals as adsorbent. The purpose of this study was to advance understanding of the mechanisms for the removal of methylene blue (MB) from aqueous solutions onto montmorillonite as an adsorbent. Preliminary experiments showed that montmorillonite was effective for this purpose and adsorption equilibrium could be reached in about 24 h. Adsorption capacity of the clay decreased with increase in temperature and ionic strength, and increased with in pH. The fitness of equilibrium data to common isotherm equations such as the Langmuir, Freundlich, Elovich, Temkin and Dubinin-Radushkevich were tested. The Langmuir equation fitted to equilibrium data better than all tested isotherm models. Thermodynamic activation parameters such as <TEX>${\Delta}G^0$</TEX>, <TEX>${\Delta}S^0$</TEX> and <TEX>${\Delta}H^0$</TEX> were also calculated and results were evaluated. As result montmorillonite clay was found as effective low cost adsorbent for removal of cationic dyes from waste waters.

Equilibrium, kinetic, and thermodynamic studies of lead (II) biosorption on sesame leaf

Sesame leaf, an agricultural solid waste, was used as low cost adsorbent for removal of Pb(II) from aqueous solution in batch mode. The biosorbent was characterized by thermo-gravimetric analysis and Fourier transform infrared spectroscopy. The influences of phase contact time, solution pH, adsorbent dosage, and initial concentrations were investigated to optimize the conditions for maximum adsorption. The experimental data were analyzed by Langmuir, Freundlich, and Koble-Corrigan isotherm models. The Koble-Corrigan and Langmuir isotherms best represented the measured biosorption data. According to an evaluation using the Langmuir equation, the adsorption capacity of the biosorbent was found to be 279.86 mg g-1, which was higher or comparable to the adsorption capacity of various adsorbents reported in the literature. The kinetics of adsorption of Pb(II) was evaluated by pseudo-first order, pseudo-second order, and intra-particle diffusion kinetic models. The experimental data fitted very well with the pseudo-second order kinetic model. The intra-particle diffusion model is not a dominant rate controlling mechanism in the sorption of Pb(II). Thermodynamic analysis showed that the adsorption was a spontaneous and endothermic process. The results indicated that sesame leaf can be used as an effective biosorbent for Pb(II) removal from aqueous solutions.

Thermodynamics, isotherm and kinetics for adsorption of Cu(II) onto Na-bentonite

Abstract The adsorption characteristic of low Cu(II) concentration onto Na-bentonite as an adsorbent as a function of pH, dosage of Na-bentonite, temperature, initial Cu(II) concentration and contact time was systematically studied using batch technique. In order to reveal the adsorption characteristic of Na-bentonite, surface area, total pore volume, mean pore diameter, IR, XRD, DTA and TG were carried out. Graphical correlation of various adsorption isotherm models like Langmuir and Freundlich have been investigated for Na-bentonite. The thermodynamic parameters such as variation of enthalpy, variation of entropy and variation of Gibbs free energy were calculated. The pseudo-first-order, pseudo-second-order, parabolic diffusion and Elovich models were used to fit the adsorption kinetics. The result showed Na-bentonite was suitable as a low cost adsorbent for removal of Cu(II) from aqueous solutions.

An alternative evaluation method for accumulated dead leaves of Posidonia oceanica (L.) Delile on the beaches: removal of uranium from aqueous solutions

Posidonia oceanica (L.) Delile is an important endemic sea plant in the Mediterranean Sea. Its dead leaves are accumulated in the beaches and cause bad view and also odour in the touristical beaches. Therefore, these dead leaves accumulated on the beaches are collected and then burned in some beaches in Turkey. In the present study, the adsorption between dead leaves and uranium were studied in the aqueous solutions. The adsorption data obeyed the pseudo-second order kinetics. Among the studied isotherms, the data were well in line with the Freundlich and Dubinin-Raduschkevich models and the maximum adsorption capacities obtained from these models were found as 5.67 and 9.81 mg g−1, respectively. Negative values of Gibbs free energy showed that the adsorption was in spontaneous nature. In conclusion, the dead leaves of P. oceanica from touristic beaches might be collected and evaluated as a low-cost adsorbent for removal of uranium(VI) from aqueous solutions.

Artificial Neural Network Modeling for Adsorption of Dyes from Aqueous Solution using Rice Husk Carbon

is one of the important industrial processes used for removal of colour, odour, turbidity & reduction of COD. In adsorption, the solute present in dilute concentration in liquid or gas phase is removed by contacting with suitable solid adsorbent so that the transfer of the component first takes place on the surface of solid and then into the pore of the solid. The present work is aimed at exploring rice husk carbon as low cost adsorbent for removal of various dyes from synthetically prepared aqueous solutions and modeling the adsorption process using artificial neural network. Rice husk carbon, developed in the present work at the laboratory scale, is analyzed for its BET surface area & is observed to be very effective for removal of dyes, namely bromocresol red, alizarin red, malachite green and methylene blue from their aqueous solutions. Further, the RHC developed. The present work highlighted the efficacy of ANN as an effective tool in modeling adsorption. The ANN models developed are using elite-ANN © .The architecture of artificial neural network is initialized & training has been carried out using the experimental data. The trained neural network is used to predict output for the given set of input parameters. Keywordsneural networks, adsorption, modeling, dyes.

Nano composite a potential low cost adsorbent for removal of cyanine acid

In this study, CuFe2O4/sawdust nano magnetic composite was prepared by chemical co-precipitation method. The nano composite was characterized by Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). SEM image showed the spherical shape with particle size 50nm for CuFe2O4/sawdust composite. The CuFe2O4/sawdust composite was used for removal of cyanine acid blue (CAB) from aqueous solution. The maximum percentage of CAB adsorption was found at pH 2 and 15min contact time with CuFe2O4/sawdust composite. Kinetic and isotherm studies were carried out. The sorption was analyzed using pseudo-first order and pseudo-second order kinetic model. The sorption kinetics was found to follow a pseudo-second order kinetic model. The equilibrium data in aqueous solutions were fitted to Langmuir and Freundlich isotherm and the equilibrium adsorption of CAB was best described by Langmuir isotherm model. The thermodynamic parameters like standard Gibb's free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were evaluated. The adsorption of CAB onto CuFe2O4/sawdust composite is exothermic and negative value of ΔG° confirms the spontaneous process. The solid composite could be conveniently regenerate after adsorption.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

Removal of copper from aqueous solutions by low cost adsorbent-Kolubara lignite

Serbian lignite from “Kolubara” deposit was used as a low cost adsorbent for removal of copper ions (Cu2+) from aqueous solutions. Lignite was subjected to the elementary and technical analysis as well as BET and FTIR analysis due to complete characterization. Basic comparison between lignite and activated carbon was also done. As a method, batch adsorption procedure was applied. Adsorption efficiency was studied as a function of the initial metal concentration, pH of the solution, contact time, and amount of the adsorbent. Optimum removal of copper ions was achieved at pH values of 5.0. About 90% of copper cations were removed in 5min of contact time from the solution with the lowest copper concentration (50mg Cu2+/l) regardless adsorbent amount, while the same effect of adsorption was achieved in 60min in case of solutions with higher concentrations of copper. It was concluded that the effect of adsorbent amount on adsorption kinetics is evident but not crucial. It was proved that the experimental results of copper adsorption fit well to a Langmuirian type isotherm which was used to describe monitored adsorption phenomena. The calculated adsorption capacities of lignite for copper adsorption decrease with increasing adsorbent amount. The study proved that tested lignite is very efficient adsorbent material, especially in case of low copper concentration in aqueous solution where the usual methods are either economically unrewarding or technically complicated. This behavior can be explained by FTIR spectrum despite a small specific surface area of lignite. Namely, many bands (peaks) are attributed to the functional groups that they are involved in chemisorption and ionic exchange, basic mechanisms of copper adsorption.

Distribution and Elimination of 14C-Ethion Insecticide in Chamomile Flowers and Oil

The residual fate of 14C-ethion labeled at the ethyl group in chamomile flowers and oil was studied. 14C-ethion and some of its degradation products have been prepared for the present investigation. 14C-residues in its flowers and oil were determined at different time intervals. Chromatographic analysis of chamomile oil extracts revealed the presence of the parent compound together with four metabolites, which were identified as ethion monooxon, ethion dioxon, O,O-diethyl phosphorothioate, and O-ethyl phosphorothioate. Effect of drying on ethion residues in chamomile flowers was investigated. Ethion residues were decreased by sun drying of chamomile flowers. The percentage of removal was 18%–47%. Effect of using low cost adsorbents for removal of ethion residues from chamomile oil was investigated. The removal percentage due to adsorption was 100% for CaO and saw dust adsorbers and for watermelon peels, bagass, and rice bran adsorbers were 36%, 41%, and 90%, respectively. Our results proved that the addition of CaO saw dust and rice bran reduced the pesticide residues, so we recommend the addition of these adsorbents during the extraction process to reduce the risk of pesticide residues on chamomile oil. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Figure S1: 1H NMR of Compound (IV)] GRAPHICAL ABSTRACT

Equilibrium Kinetics and Isotherm Studies of Cu (II) Adsorption from Waste Water onto Alkali Activated Oil Palm Ash

Problem statement: Heavy metal accumulation in waste water could affect aquatic life, human health and overall ecosystem adversely. Therefore, in recent years much emphasis has been given for the use of industrial waste material as low cost adsorbents for removal of metallic contaminants from waste water. Approach: Present study deals with the adsorption equilibrium and kinetics of Cu (II) cation using sodium hydroxide activated Oil Palm Ash (OPA). Adsorption was investigated in a batch system with respect to various parameters such as initial metal ion concentration, contact time and pH of the solution. Surface characterization of the prepared adsorbent was done by using surface area analyzer, Scanning Electron Microscope (SEM) and X-ray Fluorescence and compared with natural oil palm ash. The adsorption equilibrium data were best represented by Langmuir, Freundlich and Temkin model. Equilibrium kinetics studies were performed by Pseudo first order, Pseudo second order and Intra-particle diffusion. Results: Maximum monolayer adsorption capacity observed at 30°C was 18.86 mg g−1. Kinetic data correlated well with the pseudo second order model, suggesting that the adsorption process might be chemical sorption. The linear plots of intra particle diffusion revealed that the adsorption process was mainly governed by pore diffusion. Equilibrium uptake was increased with increase of initial concentration and contact time. Experimental data showed that about 96.03% of copper can be removed at pH 5.5. Conclusion: The research concluded that activation by alkali treatment of natural OPA would produce sufficient porosities and surface area and it has got good potential to remove Cu (II) from waste water.

Removal of Red Acid Dye from Synthetic Wastewater by Adsorption onto Low-Cost Material

Low-cost adsorbent which was burned rice husk was used in this study. The burned rice was tested with a series of packed bed in plastic bottle. The flow rate was controlled at 0.1 ml/s for all the experiment. Thomas model was used to predict the breakthrough time and all experiments were carried out at room temperature. The results indicated that the burned rice husk has a potential to be low-cost adsorbent for removal of red acid dye

Nitric acid-treated bamboo waste as low-cost adsorbent for removal of cationic dye from aqueous solution

The feasibility of nitric acid-treated bamboo waste (NBW) for the removal of methylene blue (MB) from aqueous solutions was investigated. Batch adsorption studies were conducted to study the effects of contact time (0–180 min), initial concentration (45–375 mg/L) and solution pH (2–10) on the removal of dye at 30°C. The experimental data were analyzed by using four different types of linearized Langmuir and the Freundlich isotherms. Equilibrium data fitted well with the type 1 Langmuir model, yielding maximum monolayer MB adsorption capacity of 87.719 mg/g. The kinetic data were found to conform to pseudo-second-order kinetic model with good correlation. Intraparticle diffusion model was further tested to identify the diffusion mechanism. The scanning electron micrographs showed that MB was adsorbed on the rough surface of NBW. The NBW prepared in this study was shown to be a promising low-cost material for adsorption of MB from aqueous solutions.

Assessment on the Removal of Malachite Green Using Tamarind Fruit Shell as Biosorbent

AbstractTamarind fruit shell was used as a low cost biosorbent for the removal of malachite green from aqueous solution. The various factors affecting adsorption such as agitation, pH, initial dye concentration, contact time, and temperature were investigated. It was observed that the dye adsorption capacity was strongly dependent on solution pH as well as temperature. The equilibrium data were described by the Langmuir, Freundlich, and Temkin isotherm models. The Langmuir isotherm model showed good fit to the equilibrium adsorption data and the maximum adsorption capacity obtained was 1.951 mg/g at 303 K. The kinetics of adsorption followed the pseudo‐second‐order model and the rate constant decreased with increase in temperature indicating exothermic nature of adsorption. The Arrhenius equation was used to obtain the activation energy (Ea) for the adsorption system. The activation energy was estimated to be 63.56 kJ/mol. Thermodynamic parameters such as Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) were also investigated. Results suggested that adsorption of malachite green onto tamarind fruit shell was a spontaneous and exothermic process. Present investigation suggests that tamarind fruit shell may be utilized as a low cost adsorbent for removal of malachite green from aqueous solution.