Carbon coated monolith, a mesoporous material for the removal of methyl orange from aqueous phase: adsorption and desorption studies

The cordierite monolith was successfully modified to carbonaceous material termed as carbon coated monolith (CCM). Surface studies showed about 65% of the total pore volume falls in mesopore range with acidic functionality dominating over the surface. Batch adsorption experiments were carried out to study the applicability of CCM for the removal of methyl orange (MO) from aqueous solution. Different parameters such as effect of MO concentration, contact time, initial pH, regeneration and desorption potential of CCM were studied. Optimum adsorption of MO on CCM was observed at pH 6 (27.2 mg/g). The increase in initial MO concentration from 50 to 500 mg/L leads to increase in adsorption capacity from 15.99 to 88.5 mg/g. The observed equilibration time ranged in between 5000 and 5800 min. Linear and non-linear isotherm studies showed better applicability of Freundlich model. Kinetics studies showed better fitting for pseudo-second-order model. The Weber and Morris model showed multi-linearity indicating two or more steps were involved to describe the adsorption process. Desorption studies showed maximum recovery of MO when alkaline NaOH solution was used as an eluent. The regeneration studies showed decrease in adsorption capacity from 47.93 to 23.76 mg/g after three cycles

Removal of Ni (II) from aqueous solution by an electric arc furnace slag using artificial neural network approach

An artificial neural network (ANN) was built to model the adsorption of nickel on electric arc furnace slag (EAFS). The effect of operating parameters such as pH, the initial metal ion concentration, particle size, and adsorbent dosage were investigated to optimize the sorption process. The operating variables were used as the input for a neural network, which predicted the nickel (II) ion uptake at any time point as the output. The adsorbent was characterized by SEM and BET measurements. From the experimental results the adsorption capacity of 45% was obtained at pH of 8, also as when the adsorbent dosage increases from 0.1 to 1 g/l there is an increase in the percentage removal of Ni(II) ion from 25% to 37% respectively. Further more from the particle size analysis result, it revealed that as the particle size increases from 0.5µm to 3mm the percentage removal of Ni(II) ion decrease from 52% to 33%. Finally by increasing the initial concentration of Ni(II) ion from 50 to 1000 mg L-1, the adsorption capacity also increase from 24% to 43%. The ANN models present high correlation coefficient (R²=1) was found to perform excellently in predicting the adsorption behaviour of nickel in aqueous solutions onto EAFS

Preparation, characterization and methylene blue adsorption of surfactant-templated mesoporous carbon coated monolith

This thesis work brings the preparation and characterization of mesoporous carbon coated monolith (MCCM) by using nonionic surfactant as template and its application on adsorption of methylene blue. MCCM with high surface area and pore volume was synthesized and characterized in detail. The preparation of mesoporous carbon coated monoliths consisted of polymerization, dip-coating,solidification and carbonization. MCCM have been prepared by dip-coating cordierite monoliths in a polymer solution consists of furfuryl alcohol (carbon source), F127 (template), pyrrole (binder) and nitric acid (polymerization catalyst). After solidification of the polymer, the coating was carbonized at temperature of 700 oC to obtain MCCM. The influence of concentration of the surfactant template in MCCM was investigated. It was found that by increasing the concentration of surfactant, adsorption capacity of MCCM increases from 100 to 200 mg/g. The mesoporous carbon coated monoliths are characterized by nitrogen adsorptiondesorption,thermogeravimetric analysis, scanning electron microscopy and Fourier transform infrared. The characterization study shows that the MCCM prepared in this work possesses a higher surface area (842 m2/g), pore volume (0.3 m3/g) and mesoporosity (97%) compare to previous study (MCCM by PEG). The potential of mesoporous carbon coated monolith on the adsorption of methylene blue dye was investigated. Batch adsorption experiments were carried out to find out the effects of pH (2-11), salt, contact times (4480 min), initial dye concentrations (50-400 ppm) and temperature (25, 35 and 45 oC) on the adsorption of the dye. pH was found to be the most significant factor and pH 10 was favorable for MB adsorption. Furthermore, kinetic study showed that the adsorption could be better represented by the pseudo-second-order model. Equilibrium adsorption data were predicted by two isotherms, i.e. the Langmuir and the Freundlich isotherms. The best fit to the data was obtained with the Langmuir isotherm with maximum monolayer adsorption capacity of 388 mg/g. Adsorption of MB is favourably influenced by an increase in the temperature of the operation from 388 to 440 mg/g. By associated thermodynamic parameters, the adsorption was found to be spontaneous and endothermic. Desorption study indicates that 0.1N hydrochloric acid exhibits higher elution efficiency and a quantitative recovery of MB (around 82%) can be achieved

Method and composition for making mesoporous carbon coated monolith

A method for fabricating a mesoporous carbon coated material includes the steps of mixing a precursor composition to form a polymer solution, coating a substrate in the polymer solution and heating the polymer solution and the substrate at a carbonizing temperature for sufficient time under nitrogen gas to form a mesoporous carbon coated monolith. The precursor composition includes a carbon precursor, a template, a cross-linking agent, a solvent and a catalyst. The mesoporous carbon coated monolith is characterized by a large pore volume for adsorbing multiple molecules

ORIGINAL ARTICLE Corresponding Author Removal of Ni (II) from aqueous solution by an electric arc furnace slag using artificial neural network approach

; Removal of Ni (II) from aqueous solution by an electric arc furnace slag using artificial neural network approach ABSTRACT An artificial neural network (ANN) was built to model the adsorption of nickel on electric arc furnace slag (EAFS). The effect of operating parameters such as pH, the initial metal ion concentration, particle size, and adsorbent dosage were investigated to optimize the sorption process. The operating variables were used as the input for a neural network, which predicted the nickel (II) ion uptake at any time point as the output. The adsorbent was characterized by SEM and BET measurements. From the experimental results the adsorption capacity of 45% was obtained at pH of 8, also as when the adsorbent dosage increases from 0.1 to 1 g/l there is an increase in the percentage removal of Ni(II) ion from 25% to 37% respectively. Further more from the particle size analysis result, it revealed that as the particle size increases from 0.5µm to 3mm the percentage removal of Ni(II) ion decrease from 52% to 33%. Finally by increasing the initial concentration of Ni(II) ion from 50 to 1000 mg L -1 , the adsorption capacity also increase from 24% to 43%. The ANN models present high correlation coefficient (R 2 =1) was found to perform excellently in predicting the adsorption behaviour of nickel in aqueous solutions onto EAFS

Biosorption of azoimide on almond integument: Kinetics, isotherm and thermodynamics studies

Hospital effluents are a serious problem in waterways due to azoimide that provides physical and health hazards. The removal of azoimide using powdered almond integument was studied in batch mode. Hydroxyl, carbonyl and carboxyl on the biosorbent surface were measured by titration method. The biosorption of azoimide was found to depend on the initial concentrations, pH and contact time. The equilibrium data was analyzed by using a non-linear form of Langmuir, Freundlich, Toth and Redlich-Peterson isotherm models. The fitness of data was evaluated using three error functions and correlation coefficient value (R 2). The error analysis showed three parameters models described the best biosorption in comparison of two parameters models such as Langmuir and Freundlich. The pseudo-first order, pseudo-second order and Elovich kinetic models were applied to study the kinetic behavior, and revealed applicability of the pseudo-second order model. The evaluation of thermodynamic parameters showed that biosorption process was endothermic and spontaneous. © 2013 Elsevier Ltd. All rights reserved.info:eu-repo/semantics/publishe

Optimization the process of chemically modified carbon nanofiber coated monolith via response surface methodology for CO2 capture

In the present study, a sequence of experiments was performed to assess the influence of the key process parameters on the formation of a carbon nanofiber-coated monolith (CNFCM), using a four-level factorial design in response surface methodology (RSM). The effect of reaction temperature, hydrocarbon flow rate, catalyst and catalyst promoter were examined using RSM to enhance the formation yield of CNFs on a monolith substrate. To calculate carbon yield, a quadratic polynomial model was modified through multiple regression analysis and the best possible reaction conditions were found as follows: a reaction temperature of 800 °C, furfuryl alcohol flow of 0.08525 mL/min, ferrocene catalyst concentration of 2.21 g. According to the characterization study, the synthesized CNFs showed a high graphitization which were uniformly distributed on a monolith substrate. Besides this, the feasibility of carbon dioxide (CO2) adsorption from the gaseous mixture (N2/CO2) under a range of experimental conditions was investigated at monolithic column. To get the most out of the CO2 capture, an as-prepared sample was post-modified using ammonia. Furthermore, a deactivation model (DM) was introduced for the purpose of studying the breakthrough curves. The CO2 adsorption onto CNFCM was experimentally examined under following operating conditions: a temperature of 30–50 °C, pressure of 1–2 bar, flow rate of 50–90 mL/min, and CO2 feed amount of 10–40 vol.%. A lower adsorption capacity and shorter breakthrough time were detected by escalating the temperature. On the other hand, the capacity for CO2 adsorption increased by raising the CO2 feed amount, feed flow rate, and operating pressure. The comparative evaluation of CO2 uptake over unmodified and modified CNFCM adsorbents confirmed that the introduced modification procedure caused a substantial improvement in CO2 adsorption