Adsorption of phenol by sugarcane biochar@bentonite

Abstract

Phenol is a hazardous organic chemical that is introduced into the environment by industrial and pharmaceutical discharges. Bentonite can remove harmful substances in the environment and is widely used in the field of environmental geotechnical engineering. However, the adsorption effect of bentonite on organic pollutants is poor. At the same time, its permeability and expansion characteristics are easily affected by saline solutions and acid aqueous solutions. Biochar, as a simple and low-cost adsorbent, can effectively remove inorganic and organic pollutants. The purpose of this study is to prepare a composite material including biochar and bentonite and improve the removal efficiency of phenol and the impermeability of bentonite in saline and acidic aqueous solutions. The adsorbents were characterised by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller nitrogen (N2) method. The permeability coefficients of bentonite and sugarcane biochar@bentonite (SuBC@Ben) were determined. The effects of bentonite, SuBC@Ben and sugarcane biochar on the removal of phenol under different contact times, concentrations, pH values and temperatures were studied. The results show that the change range of the SuBC@Ben permeability coefficient is not obvious with the increase in saline solution concentration, indicating that SuBC@Ben has good impermeability in saline solution.