Study on the aerobic biodegradation of lignin by activated sludge reactor

The aerobic biodegradation of lignin was studied by running an activated sludge reactor in laboratory. The results show that the pH of the effluent changes little between 7.2 and 7.6, and the aerobic biodegradation ratio of lignin is more than 40%. The sludge characters are improved apparently as the reactor runs with time. In conclusion, the aerobic microbe groups which can decompose lignin have been cultivated in the reactor. Besides, cometabolic substrate has great influence on the aerobic biodegradation of lignin. When the mass proportion of glucose occupies 5% in the influent, lignin decomposition efficiency reaches the highest value of 49%. However, lignin can't be completely biodegraded by these aerobic microbe groups because the chemical groups which have a strong absorbance at ultraviolet 276nm can't be damaged easily by these microorganisms.