Optimizing the mechanism and conditions of adsorption: the role of sludge biochar in the disposal of rhodamine b in water

Using residual sludge from wastewater treatment plants as raw material, raw sludge biochar (RCF) and Fenton conditioned biochar (FNB) were prepared respectively through pyrolysis of raw sludge and Fenton conditioned sludge. They were used for the removal of Rhodamine B pollutants from wastewater. The performance of RCF and FNB were compared, and the mechanisms of Rhodamine B removal by RCF and FNB were explored through characterization tests (SEM, BET and XRD). The dosage of FNB and the initial pH of the solution were further studied. The adsorption process of FNB on Rhodamine B was studied through kinetic model and isothermal adsorption model. The results showed that when the initial concentration of Rhodamine B was 60mg/L, FNB dosage was 0.2g/L, pH was 8, adsorption time was 240min, and temperature was 24°C, the removal rate of Rhodamine B in the solution could reach 95.6%. Microscopic analysis showed that iron compounds were formed on the surface of FNB particles, roughness and specific surface area increased, and the adsorption performance of FNB was enhanced. The adsorption kinetics showed that the process of FNB adsorbing Rhodamine B is mainly physical adsorption.