[Study on toxicity of phenol to anaerobic granular sludge]

To understand the toxicity of phenol to anaerobic granular sludge, the changes of specific methanogenic activity (SMA), extracellular polymeric substance (EPS) constituents and coenzyme F420 concentration of anaerobic granular sludge at various phenol concentrations were investigated. Meanwhile, Fourier transform infrared spectrometry was used to analyze the structure of EPS. The results show that the phenol has little effect on anaerobic granular sludge when the concentration of phenol is less than 100 mg/L. When the phenol concentration increases from 100 mg/L to 400 mg/L, the special methanogenic activity (SMA) decreases from 173.4 mL/(g x d) to 57.6 mL/(g x d), coenzyme F420 concentration decreases from 0.14 micromol/g to 0.08 micromol/g, and EPS concentration, which is represented by TOC, decreases from 33.1 mg/g to 15.0 mg/g, when the SMA and the concentration of coenzyme F420 and EPS in the blank test are 259.6 mL/(g x d), 0.154 micromol/g and 38.5 mg/g respectively. The analysis of molecular structure of EPS with Fourier transform infrared spectrometry shows that it has big effect on molecular structure of EPS when the phenol concentration is 800 mg/L.