A.C. Affam
Abstract
Conventional steam activation pyrolysis of waste materials such as oil palm kernel shell for production of biochar was investigated using central composite design. Conventional steam activation was carried out via an initial carbonization of oil palm kernel shell to obtain biochar and thereafter steam ...
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Conventional steam activation pyrolysis of waste materials such as oil palm kernel shell for production of biochar was investigated using central composite design. Conventional steam activation was carried out via an initial carbonization of oil palm kernel shell to obtain biochar and thereafter steam activation of the biochar using the conventional heating to produce activated carbon. Additionally, removal of chemical oxygen demand and colour was studied alongside the production. Optimum yield was obtained at about 90 min and 725oC. Out of the time duration, 80 min was for carbonation and 10 min was for steam activation. Further extension of time was not significant whereas increasing temperature was able to increase the pores found on the biochar. Under the optimum condition, fixed carbon was 19.39%, chemical oxygen demand and colour removal were 32.02 and 61.15%, respectively at 90 min adsorption time. However, when time was extended to 120 min, chemical oxygen demand (48.2%) and colour (94.19%) removal were achieved. The Brunauer–Emmett–Teller surface area and micropore area of the oil palm kernel shell based activated carbon was 620.45 m2/g and 550.4 m2/g, respectively. The conventional steam activation is an effective method that can be employed in production of activated carbon from waste oil palm kernel shell.
B. Te; B. Wichitsathian; C. Yossapol; W. Wonglertarak
Abstract
Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design ...
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Mesoporous pellet adsorbent developed from mixing at an appropriate ratio of natural clay, iron oxide, iron powder, and rice bran was used to investigate the optimization process of batch adsorption parameters for treating aqueous solution coexisting with arsenate and arsenite. Central composite design under response surface methodology was applied for optimizing and observing both individual and interactive effects of four main influential adsorption factors such as contact time (24-72 h), initial solution pH (3-11), adsorbent dosage (0-20 g/L) and initial adsorbate concentration (0.25-4.25 mg/L). Analysis of variance suggested that experimental data were better fitted by the quadratic model with the values of regression coefficient and adjusted regression coefficient higher than 95%. The model accuracy was supported by the correlation plot of actual and predicted adsorption efficiency data and the residual plots. The Pareto analysis suggested that initial solution pH, initial adsorbate concentration, and adsorbent dosage had greater cumulative effects on the removal system by contributing the percentage effect of 47.69%, 37.07% and 14.26%, respectively. The optimum values of contact time, initial solution pH, adsorbent dosage and initial adsorbate concentration were 52 h, 7, 10 g/L and 0.5 mg/L, respectively. The adsorption efficiency of coexisting arsenate and arsenite solution onto the new developed adsorbent was over 99% under the optimized experimental condition.
