Biological evaluation of different inoculums used for ready biodegradability of chemicals

The biodegradability of 2,4-dichlorophenol and biphenyl was tested by closed bottle test and manometric respirometry test with different activated sludge and secondary effluent samples from LD and DT Municipal Wastewater Treatments Plants. In closed bottle test, both rates of degradation of 2,4-dichlorophenol can reach the target by LD and DT secondary effluent samples. However, biphenyl was refractory and degradable, respectively. Compared with closed bottle test, the results of manometric respirometry test indicated that biphenyl was degradable by activated sludge of LD and DT. Moreover, 2,4-dichlorophenol was refractory and easily degradable, respectively. From the results, we can conclude that inoculums and test methods have a great effect on the degradation of chemicals. Therefore, standard test method and inoculum are necessary for degradation of chemicals.