Advanced oxidation in combination with carbonaceous materials for the treatment of waste water

Abstract

Water is considered to be a fundamental part for our entire and sole presence. However, the source is further getting limited due to extreme water pollution, which is caused by the human activities and rapid growth of industrialization. Although, industrialization is making our life better but on the other hand generating tremendous amounts of wastes, adulterating nearby water bodies. These toxic and carcinogenic wastes are easily not recoverable. In this study Fenton’s process was discussed and investigated as an Advanced oxidation process (AOP) using Fenton’s reagent for decontamination of cationic dye from wastewater. Cationic dye used in this process are malachite green. Different parameters which affect the reaction such as the initial Fe2+ concentration, solution pH, initial H2O2 concentration, reaction temperature and concentration of target dye had been studied. For eliminating MG from aqueous solutions, the experimental Fenton's reaction has shown to be highly effective. For the Fenton oxidation of MG, the variations of parameters for [H2O2]0, [Fe2+]0, [MG]0, pH, and temperature were 0.1 ml/L to 0.2 ml/L, 25 ppm to 100 ppm, 10 mg/L to 50 mg/L, 2 to 10, and 25°C to 40°C respectively. The optimal conditions for oxidative degradation of malachite green were found to be pH at 4, hydrogen peroxide (H2O2) concentration at 0.2 ml/L, initial ferrous concentration at 50 ppm for 10 ppm of malachite green dye concentration at 30°C. Under these optimal reaction conditions, removal of malachite green dye was experimentally found to be 99% after completion of 90 minute of reaction. Methodology involved in the treatment of raw rice husk, activated rice husk and chemically treated activated rice husk as an efficient adsorbent to remove cationic and anionic dyes from contaminated water were investigated. Parameters such as solution pH, concentration of target organic pollutants, reaction time, adsorbent dose and reaction temperature were also studied to improve adsorption process. The adsorption kinetics and thermodynamic studies were calculated of all the adsorbents to find out the nature of the reaction. Data obtained from kinetics study were fitted in pseudo second order model and data obtained from thermodynamics study indicates the reaction was exothermic in nature. For the Adsorption process of MG, the variations of parameters for adsorbent dose, [MG]0, pH, and temperature were 0.5 g/L to 2 g/L, 10 mg/L to 50 mg/L, 2 to 10, and 25°C to 40°C respectively. Under all these parameters which affect the reaction rate, 99% removal of malachite green dye was removed in this study. Comparative study on the removal of dye using thermally synthesized biochar and Fenton’s process and its Batch and Optimization studies were done to determine the suitable and novel techniques for decontamination of emerging organic pollutants from wastewater.