Effect of sludge property on the synthesis, characterization and sorption performance of sludge-based biochar

In the present study, the effect of sludge property, including granular and flocculent structures, on the influence of biochar synthesis, characterization and application for Methylene blue (MB) wastewater treatment were investigated. The chemical and physical characteristics of prepared aerobic granular sludge-biochar (AGS-BC) and activated sludge-biochar (AS-BC) were detected by spectral approaches. Results implied that AGS-BC exhibited a much higher value of Brunauer-Emmett-Teller (BET) surface area (905.1 m2/g) than that of AS-BC (281.35 m2/g). The optimum contact time of AGS-BC and of AS-BC for MB sorption was both 180 min. The adsorption rates of MB onto two types of biochars were conformed to pseudo-second order kinetic models, while sorption equilibrium data were fitted to Langmuir adsorption model with maximum MB adsorption capacities of 377.9 and 176.5 mg/g for AGS-AC and AS-AC, respectively. It is expected that AS-BC and AGS-BC have wide applicability for dye removal from various wastewaters. © 2019 Elsevier Ltd