DEVELOPMENT OF WATERMELON RIND ACTIVATED CARBON FOR REMOVAL OF BENZENE AND TOLUENE FROM OIL WASTEWATER

Abstract

This study focused on developed activated carbon from watermelon rind for the removal of benzene and toluene from oil-spilled wastewater in real-time environments. The activated carbon was developed from biochar, which was developed from watermelon rind. The activated carbon was developed via chemical activation using two different reagents (sulphuric acid and zinc chloride). The influence of process parameters like time, temperature, and impregnation ratio (IR) was investigated during the preparation of activated carbon. The adsorbent was characterized with Fourier Transform Infra-Red Spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) analysis and Scanning Electron Microscopy (SEM). The activated carbon was used in batch adsorption on oil wastewater. The effect of contact time, adsorbent dosage, and temperature on the adsorption process was studied and optimized using response surface methodology. Studies on adsorption isotherms, kinetics, and thermodynamics were carried out. It was discovered that at higher temperature and time, fixed carbon was lowered. The results showed that optimum temperature, time and IR for activated carbon was at 500oC, 2.165 hrs and 2/1 respectively, with fixed carbon of 60%. The activated carbon produced with sulphuric acid showed a better result than zinc chloride, with the BET results showing a surface area of 900.361 m2/g. FT-IR showed the presence of hydroxyl and carboxyl groups, which have affinity for benzene and toluene and SEM showed that the morphology of the watermelon rind had changed. The effect of temperature, time, and adsorbent dosage on showed an increase in removal efficiency up until equilibrium and thereafter a downward spiral with the optimum temperature, time and adsorption dosage at 32.5oC, 120 mins and 0.7g. Langmuir best fits the benzene adsorption process. The pseudosecond- order kinetics had a better fit during the kinetic studies. The thermodynamic studies showed that the process was exothermic, spontaneous, feasible, and favorable.