Kinetic Approach to Estimate the Biodegradability of Different Types of Dyestuffs Using Respirometry

초록

Bio-kinetic constants such as maximum specific growth rate (μmax) and half saturation constant (Ks) were determined using a respirometer for the artificially formulate dying wastewater containing different dyes and auxiliaries to estimate the biodegradability of the dying wastewater. After activated sludge was acclimated to the artificial dying wastewater and cultivated, it was innoculated to respirometer and bio-kinetic constants were determined. Maximum specific growth rate (μmax) was 0.06 1/hr, which is 3 to 15 times smaller than that of the typical activated sludge for sewage treatment. The half saturation constant (Ks) was 210 mg/L, which is three times greater than that of the normal sludge. Considering that the biodegradability increases as μmax is higher and Ks is lower, the dying wastewater seemed to be relatively refractory and not to bio-degrade well. Bio-kinetic constants were also obtained for reactive, acid and disperse dyestuffs and compared with those for enzyme. Using the bio-kinetic data, the engineering parameter such as HRT and the ratio of returned sludge (α) can be corrested to optimize the plant.