[Effect of pH on the biosorption behavior of 4-CP onto anaerobic granular sludge]

The effect of the initial pH value on the biosorption behavior of 4-CP onto anaerobic granular sludge was investigated in this paper. The experimental results indicated that the initial pH value was the important parameter affecting the biosorption of 4-CP, and the biosorption capacity of anaerobic granular sludge decreased with the increase of pH value. The biosorption capacity of 4-CP was 6.675 mg/g at pH 2.25, while it was only 0.260 mg/g at pH 10.27. The equilibrium isotherm of 4-CP biosorption by anaerobic granular sludge was investigated at different pH values, and the results showed that the biosorption behavior of 4-CP could be described by the Langmuir model quite well. The coefficients of the Langmuir and the Freundlich equations of 4-CP biosorption by anaerobic granular sludge at different pH values were given.