Adsorption Properties of Methyl Orange in Water by Sheep Manure Biochar

Sheep manure was used to prepare biochar under pyrolysis temperature of 600 degrees C. The structural features of biochar were characterized by elemental analysis, BET analysis and scanning electron microscopy. The effects of pH, biochar dosage, adsorption time, temperature on adsorption of methyl orange (MO) in water by sheep manure biochar, as well as its adsorption mechanism, were investigated via batch experiments. The results showed that the sheep manure biochar had large specific surface area, abundant hole structure and high aromaticity and polarity. When temperature was 25 degrees C, MO concentration was 20 mg/L, initial pH was 4.0, and biochar dosage was 0.6 g/L, the adsorption achieved balance at about 250min, and the MO removal rate reached to 92.55%. Pseudo second-order kinetic model and Langmuir model could more accurately describe the adsorption behavior of MO onto sheep manure biochar, and the theoretical maximum adsorption capacity was 42.513 to 45.563 mg/g. Besides, the process is a favorable adsorption. Thermodynamic studies showed that the adsorption was a spontaneous, endothermic and entropy-increasing process. Sheep manure biochar could be used as a good adsorption material for MO in water, which achieved the goal of controlling waste by waste.