Within this study the mediated detoxification of spent sulphite liquor via laccase from Trametes versicolor was analysed and optimised using an in-situ NMR-spectroscopy method. The enzymatic degradation kinetic was optimised using the degradation rate of aromatic compounds as indirect parameter. Via response surface methodology the impact of the temperature, the pH and the enzyme concentration was analysed and the conditions were optimised focusing on optimal detoxification. The results of the statistical calculation revealed a valid statistical model for the optimal impact on the aromatic degradation with a temperature of 31 °C, a pH of 6 and a laccase concentrations of 179 U g^-1 dry matter of spent sulphite liquor. By using these conditions 88.73 % of aromatic compounds could be degraded.