Bioreactors for the rapid determination of biodegradable dissolved organic carbon (BDOC) in drinking water: Feed mode impact

Bioreactors performing at a stable temperature of 20 degrees C were used to achieve a rapid determination of the amount of biodegradable dissolved organic carbon (BDOC) present in ozonated water. Two feed modes, continuous feed and batch feed,were compared and evaluated. Bioreactors fed from holding tanks filled weekly with water passed through 1 and 75 mu m filters were found to perform better in the short term (7 months after start-up) than those fed continuously with water filtered on 75 mu m, in terms of the reduction in the amount of DOC between the intake and outflow points of the bioreactors, or BDOC (biodegradable dissolved organic carbon). It is believed that the difference in performance of batch-fed and continuously-fed bioreactors can be attributed to the more rapid bacterial colonization of batch-fed bioreactors. Moreover, it was observed that biological growth in the prefilter had an important role in the overall removal of BDOC through the continuously-fed bioreactor system.