Abstract
The efficient degradation of lignin in kraft pulp wastewater by ozonolysis and microbial degradation was presented. The effects of operational conditions such as pH and temperature on the degradation of lignin aromatic ring by ozone were experimentally clarified. The lignin aromatic ring was degraded by the ozonolysis into various low-molecular weight organic acids such as muconic acid, malefic acid, and oxalic acid. In the microbial degradation of ozonolyzed wastewater using an oxalic acid degrading microorganism, strain A28, cells grew in a typical diauxic growth, i.e. the oxalic acid was degraded only after the exhaustion of acetic acid. As a result, it was found that after ozonolysis of kraft pulp wastewater microbial degradation by strain A28 was effective method for the complete degradation of lignin in it.
