Study on Biodegradability of Acrylic Retanning Agent DT-R521

Abstract

The methods of respiratory curve and COD₃₀ were adopted to evaluate the biodegradability of acrylic retanning agent DT-R521, which was used as the substrate of microorganism. The main results obtained by the method of respiratory curves were as follows: When the concentration of substrate was 0 3000mg/L, the respiratory curves of the substrate were under the curve of endogenous, which showed that the substrate has inhabiting effect on microorganism. When the concentration of the substrate was 1500mg/L, the utilization of the substrate by microorganism was the most. The main results obtained by the method of COD₃₀ were as follows: when sludge concentration was 1000mg/L and pH was 7, the biodegradation rate of 500mg/L DT-R521 was 26.21%. Under above condition, the biodegradation rates of DT-R521 with other concentrations were much smaller. Moreover, as indicated in the respiratory curves, the effect of sludge concentration, salinity and co-metabolism on the biodegradability of the substrate was obvious. Under the experimental conditions, when the concentration of the substrate was 1500mg/L, the sludge concentration was 3000mg/L and salinity was 0.7%, the biodegradability of the substrate was the best. The glucose was as co-metabolism substrate and when its concentration was 300mg/L, the biodegradability of the substrate was obviously increased.