Potential Use of Biochar from Sugarcane Bagasse for Treatment of Textile Wastewater

Abstract

The use of activated carbon for the treatment of wastewater from textile industries is integral to the production of reusable water. Despite its abundance in countries where textiles are produced and the apparent suitability of sugarcane bagasse (SCB) as a feedstock for the production of activated carbon, this material is not used commercially as it is uneconomic to produce when compared to other biomass sources. This chapter reports on the chemical pretreatment of SCB as a means to increase the production of biochar from SCB. The thermal degradation kinetics of bagasse was examined by thermal gravimetric analysis (TGA). Furthermore, Fourier transfer infrared (FTIR) spectroscopy of evolved gases was recorded to better understand the mechanism by which the treatment process affects the degradation of the SCB during pyrolysis. Two chemicals were used as chemical additives-ammonium sulphate (AS) and diammonium phosphate (DAP). These were added to bagasse as solutions at different concentrations ranging from 0.01 to 1 M prior to pyrolysis. It was generally found that the bagasse treated with additives caused mass degradation at lesser temperatures and formed considerably greater yields of biochar than untreated raw bagasse. Greater concentrations of additives improved the char yield significantly but passed through an optimum additive concentration for char yield. It was reasoned that the optimum was caused by a change in reaction mechanism when additive concentrations became high as evidenced by the FTIR spectrum measured-although this mechanism varies with the different additives. The addition of chemical additives to SCB so as to improve char yield may provide a route by which the SCB may be an economically attractive source of biochar.