Areca catechu fronds show higher capability for removal of color and COD and were utilized as an adsorbent for adsorption
process. Areca catechu fronds activated carbon (AC) undergoes activation process after carbonization under purified
carbon dioxide and turned as activated carbon. Three variables were chosen for the preparation optimization which
consists of temperature, activation time and impregnation ratio in order to study the effect toward the removal of color
and COD from cotton textile mill wastewater. For this study, the response surface methodology (RSM) was employed.
Quadratic model were develop based on three variables and responses of color and COD. High values of the coefficient
determination, R2
were obtained from analysis of variance (ANOVA) for both responses. The optimum Areca catechu
fronds activated carbon (AC) preparation condition was established at temperature 797 °C for 1.57 hour of activation
time and 2.75 impregnation ratios, corresponding to the removal of color and COD with 78.83 and 62.41%, respectively.
In this study, the photocatalytic degradation of batik wastewater in the presence of zinc oxide (ZnO) as photocatalyst was
investigated. The effect of various operating parameters, such as pH of batik wastewater, catalyst dosage and aeration
on the photocatalytic degradation process, was examined. The mineralization of batik wastewater was also evaluated
through chemical oxygen demand analysis. The decolorization of batik wastewater was enhanced at acidic conditions
(pH3) which was 88.2% after 10 h irradiated under solar light, meanwhile its mineralization was 286 mg/L after 12 h
irradiation time. The data obtained for photocatalytic degradation of batik wastewater was well fitted with the LangmuirHinshelwood
kinetic model. It can be concluded that batik wastewater could be decolorized and mineralized under solar
light irradiation with presence of ZnO.