No abstract

In recent years, toxic pollutants in industrial wastewater are seriously considered as one of the environmental problems due to the heavy metals present in it. Currently, biosorption has been strongly recommended by researchers as an efficient and economical technique to reduce the amount of heavy metals in the different industrial wastewater sources. Chitosan and sugar bagasse ash are the well-known biosorbents due to their low cost, available and effective in adsorption process. In this study, the composite biosorbent was prepared by mixing chitosan and sugar bagasse ash prepared by microwaving at a ratio of 1:5 (ASB-CBs) in acid condition. Adsorbents were characterized by SEM analysis method and FTIR infrared spectra. The parameters affecting the Pb(II) and Cd (II) adsorption such as pH, adsorption time, dose of adsorbent was studied by running the batch experiments. Research data show that the optimal pH for the biosorption process is 5.0. Experimental data is described by the Freundlich equation. Thermodynamic process is also studied in which the negative free Gibbs energy indicated the metal ions adsorption on the ASB-CBs was spontaneous and endothermic nature.

The synthesis of TiO2-chitosan-glycerol (TiCsG) beads was prepared to determine the optimum condition for dye removal under natural sunlight. By using the orthogonal array design with five parameters (ratio of TiO2/Chitosan, initial concentration of dyes, pH of solution, irradiation time, dose of TiCsG) to analyze their interaction such as well as optimizing the photocatalytic process. The significant parameters influent in the removal of Acid Blue 193, MO, NWY dyes were irradiation time (p = 0.011) and the ratio of TiO2/chitosan (p = 0.025), while the initial concentration of dyes, pH of dye solution and dose of TiCsG were unimportant factors with p > 0.05. The optimum of factors based on the ratio of signal per noise to attain the highest dye removal ability of TiCsG was the percentage of TiO2/chitosan = 2 % w/w (level 2), initial concentration of dye at level 5 (10 mg/L of AB 193, 5 mg/L for MO and 100 mg/L for NWY), pH =4.5 (level 2), irradiation time =1.5 h (level 5) and dose of TiCsG =0.2 g/mL (level 4).