Synthesis and characterization of textile sludge biochar for oil adsorption

Abstract

Oil contamination such as oily waste from industries is considered as one of the major problems to the sea and also public watercourse. It is also detrimental to marine life and the overall aquatic ecosystem. Thus, this study focuses on the oily wastewater treatment by adsorption process and investigated the potential of textile sludge waste from textile factory which is considered to be abundant in landfills as precursor for biochars. Textile sludge biochars (TSB) was prepared by carbonization in the laboratory tube furnace at a high temperature of 700 °C and held for 60 minutes, with 10 °C/min heating rate and 0.2 L/min of N2 gas flow. Biochar yields and moisture content had been reduced while ash and carbon content had been increased after carbonization. Then, TSB was characterized using Fourier transform infrared (FTIR), field emission scanning electron microscopy (FE-SEM), Carbon Hydrogen Nitrogen Oxygen (CHNO), pH zero point charge and Brunauer-Emmet- Teller (BET) surface area. The effects of adsorbent type, pH, initial concentration of simulated oily wastewater, contact time, adsorbent dosage, and temperature towards adsorption capacity of simulated oily wastewater were investigated. The optimal adsorption process condition obtained was at pH 7.4±2, 200 ppm initial concentration of simulated oily wastewater, 60 minutes contact time, 1 mg/ml dosage of biochar 700 °C (BC700), and temperature of 313K with maximum adsorption capacity of 173.4± 0.589 mg/g. The BET study showed that the BC700 has a surface area of 195 m2/g and has a rough surface from the results of FE-SEM which shows that BC700 has the ability to attract oil. The kinetics of adsorption is well described by pseudo-second order while the adsorption equilibrium is well represented by Langmuir isotherm. A regeneration study was carried out and it shows that TSB has the potential for oily wastewater treatment and can be regenerated until five cycles. The findings provided an alternative for low cost and effective adsorbent for oily wastewater treatment.