Equilibrium, kinetics and thermodynamic studies: adsorption of Remazol Black 5 on the palm kernel shell activated carbon (PKS-AC)

The removal of Remazol Black 5 from the synthetic wastewater using palm kernel shell activated carbon was investigated in terms of initial pH, initial concentration, contact time and temperature. The optimum pH was found at acidic range, pH 2. For equilibrium studies, two isotherm models were used in this study, which is Freundlich and Langmuir, for different temperatures and it is found that Freundlich fitted experimental data very well. In the kinetics study, pseudo-first order and pseudo-second order were tested; the latter equation showed the best represent the experimental data. The change in entropy and enthalpy for an adsorption of the dye were estimated -24.26j/mol K and -9.246kJ/mol respectively

Utilization of MATLAB to Simulate Kinetics of Transesterification of Palm Oil-Based Methyl Esters with Trimethylolpropane for Biodegradable Synthetic Lubricant Synthesis

This paper presents the simulation work on kinetic study for the transesterification reaction between palm oil-based methyl ester with trimethylolpropane to produce biodegradable lubricant base oil. The reaction mechanism involves three stepwise reversible series-parallel elementary reactions. New kinetic modeling approach is needed in this field due to the limitation of the earlier kinetic models developed for this reaction. The earlier kinetic study made use of many assumptions in order to simplify the solutions. In this work, new rate equations were derived from the actual reaction mechanism, and MATLAB was used to obtain the simultaneous solutions of the rate equations. The results obtained were compared with the experimental data used in the earlier study. The new simulation approach was found to describe the experimental values satisfactorily

Removal of glyphosate from water: applying coupled Sequencing Batch Reactor (SBR)-adsorption method

Wastewater discharged from Glyphosate manufacturing is a major environmental concern due to its complicated treatment process. In this study, the performance of a sequencing batch reactor (MSBR)-adsorption process treating Glyphosate wastewater was investigated. Operation results from SBR process showed that effluent's chemical oxygen demand (COD) removal efficiency, total suspended solids (TSS) and total phosphorus (TP) were 40 %, 105 mgL-1 and 55 mgL-1, respectively. However, the result of TP concentration did not meet the discharge limitation. The SBR effluent was then undergone an adsorption process using palm kernel shell-based activated carbon (PKS-AC). Minimum adsorbent dosage of 7 gL-1 was needed to further reduce TP concentration to discharge limitation of 2 mgL-1

Optimization of flocculation process for cut-stone wastewater: effect of rapid mix parameters

Wastewater produced from stone industry of Iran causes serious environmental problems associated with slurry disposal. In traditional method, many ponds are required for clarifying. The use of filtration and addition of chemicals enhance the efficiency of operation as well as saving laborer cost. The polymer bridging mechanism is responsible for flocculation of suspended particles. It was found that the increase of rapid mix velocity reduced the residual turbidity substantially except for the dosage of 0.2 mg of polymer. The addition of polymer was able to enhance flocs strength. For higher dosages of polymer, a direct relationship between increasing rapid mix velocity and reduction of turbidity was observed. The values of aggregation rate constant Kapp were calculated to evaluate the effects of rapid mix velocity and dosage of polymer on residual turbidity. The maximum value of Kapp = 7.2 x 10-3 was obtained for the rapid mix velocity 200 rpm and dosage of polymer 1 mg/l

Kinetic and isotherm studies for lead adsorption from aqueous phase on carbon coated monolith

Adsorption of lead [Pb(II)] ions on two different types of carbon coated monoliths (CCM 600 and CCM 8000) was investigated with variations in the parameters such as agitation speed, pH, contact time, and Pb(II) initial concentration. Optimum Pb(II) adsorption was observed at pH: 5. The observed equilibration time on CCM 600 and CCM 8000 was 470 min and 350 min, respectively while, the equilibrium adsorption capacities were 14.2 mg/g and 15.2 mg/g at 50 mg/L initial Pb(II) concentration. The adsorption capacities on CCM 600 and CCM 8000 increased to 48 mg/g and 53.5 mg/g at 250 mg/L initial Pb(II) concentration. Linear and non-linear isotherm studies showed that equilibrium data better fitted to Freundlich isotherm model. Kinetic studies showed better applicability of pseudo-second order kinetics model. It was concluded that CCM 8000 showed better performance for Pb(II) ions removal compared to CCM 600

Modelling of single and binary adsorptions of heavy metals onto activated carbon - equilibrium studies

A series of batch laboratory studies were conducted to investigate the suitability of activated carbon SA2 for the removal of cadmium ions and zinc ions from their aqueous solutions. The single component equilibrium data were analyzed using the Langmuir and Freundlich isotherms. Overall, the Langmuir isotherm showed a better fitting for all adsorptions under investigation in terms of correlation coefficient and error analysis (SSE only 18.2 for Cd2+ and 47.95 for Zn2+). As the binary adsorption is competitive, extended Langmuir models could not predict the binary component isotherm well. The modified extended Langmuir models were used to fit the binary system equilibrium data. The binary isotherm data could be described reasonably well by the modified extended Langmuir model, as indicated in the error analysis

Prediction of the effects of cone tip diameter on the cyclone performance

This technical note presents a computational fluid dynamics (CFD) calculation to predict and to evaluate the effects of cone tip diameter on the collection efficiency and pressure drop of gas cyclones. The simulation was realised using a Reynolds stress model (RSM) for turbulent modelling and discrete phase model (DPM) for particle trajectories calculation. A refined mesh on the cyclone cone was also applied to ensure a better prediction on the effect of cone tip diameter to the collection efficiency and pressure drop. It was found that CFD simulations excellently predict the collection efficiency and pressure drop of a cyclone of different cone dimensions with a maximum deviation of 5.5% from the presented experimental data. The physical mechanism for reduced cyclone tip diameter has also been successfully elucidated. The results obtained from the computer modelling exercise have demonstrated that CFD with the RSM turbulence is an effective method for modelling the effect of cyclone cone tip diameter on its performance

Adsorption of nickel on electric arc furnace slag: batch and column studies

The ability of electric arc furnace slag (EAFS), a by-product of the steel industry to adsorb nickel [Ni(II)] from an aqueous solution, was investigated by both batch and column operations. The characterization studies showed the mesoporous nature of EAFS with dominance of acidic sites. The adsorption was found to be dependent on the adsorbent dosage, contact time, the pH, and initial metal ion concentration. Optimum Ni(II) uptake was 160.92 mg/g at 1000 mg/L initial concentration with equilibration time 216 h. Adsorption follows the pseudo-second-order kinetics model. Linear and non-linear isotherm models revealed the applicability of the Langmuir model confirming monolayer adsorption. Both the column bed capacity and the exhaustion time increased with increase in bed height. The saturation time was found to increase from 42 to 46 h with a decrease in the flow rate from 15 to 5 mL/min. The bed depth saturation time and Thomas models were evaluated. The experimental breakthrough curves agreed well with the predicted model

Computer modelling of phase change materials using the orthogonal collocation method

A computer program had been developed for aone-dimensional, orthogonal collocation model of a packed bed heat storage system. The system comprised of a cylindrical storage tank filled with phase change material (PCM) encapsulated in spherical containers. This paper also presented the thermal performance simulation of packed bed heat storage system using PCM during charging and discharging process. Paraffin wax was chosen as PCM, and air was chosen as heat transfer fluid (HTF).The enthalpy method was used in the model to accommodate the phase change behaviour of PCM over a range of temperature. It was shown that the governing equations were two energy conservation equations written for HTF and PCM. Both governing equations were numerically solved by applying orthogonal collocation approach implemented using MATLAB. The results obtained by solving the model using the orthogonal collocation method were initially validated with experimental results in the literature. The model covered through-flow conditions for charging and discharging the thermal heat storage within the air. In this paper, the complete computational model was simplified and efficient enough to interface with a larger program simulating a heat storage system. The simulations were conducted in order to derive the temperature profiles of HTF and PCM as well as to estimate the time required to complete charging and discharging of PCM

Synthesis of Jatropha curcas-based methyl ester and ethyl ester as biodiesel feedstocks

Research on the use of Jatropha curcas triglycerides as biodiesel feedstock has received worldwide attention due to its inherent characteristics. Unlike palm oil, J. curcas oil is not edible, and thus, it will not disturb the food supply. However, to the researcher's experiences with the synthesis of J. curcas, oil-based biodiesel has shown that the fuel characteristics depend largely on the type of alcohol used as the excess reactants. Transesterification reaction is chosen for this process with sodium methoxide as the catalyst. Comparison studies on the yield of esters using methanol and ethanol, as well as the impacts on the reaction rate are discussed. The effects of reaction time and molar ratio on the reaction conversion are also examined. The determination of reaction yield is based on the conversion of triglycerides into alkyl esters as the main product. The findings are described as follows: the highest percentage yield of product is attained at 96% for methanol as an excess reactant, and this is 90% when ethanol is used. The optimum conditions of parameters are achieved at 6:1 molar ratio of alcohol to triglycerides, 50 min of reaction time and reaction temperature of 65°C for methanol and 75°C for ethanol. The biodiesel properties of both ester fuels were determined according to the existing standards for biodiesel and compared to the characteristics of diesel fuel