A two-stage anaerobic system for biodegrading wastewater containing terephthalic acid and high strength easily degradable pollutants.

The high strength easily biodegradable pollutants (represented by CODE) are strong inhibitors of terephthalic acid (TA) anaerobic biodegradation. At the same time, TA can inhibit easily biodegradable pollutants removal under anaerobic conditions to a limited extent. This mutual inhibition could happen and cause a low removal efficiency of both TA and CODE, when the effluent from TA workshops containing TA and easily biodegradable pollutants are treated by a single anaerobic reactor system. Based upon the treatment kinetics analysis of both TA degradation and CODE removal, a two-stage up-flow anaerobic sludge blanket and up-flow fixed film reactor(UASB-UAFF) system for dealing with this kind of wastewater was developed and run successfully at laboratory scale. An UASB reactor with the methanogenic consortium as the first stage removes the easily biodegradable pollutants(CODE). An UAFF reactor as the second stage is mainly in charge of TA degradation. At a CODE loading of 15.3 g/(L.d) and a TA loading of 1.4 g/(L.d), HRT 18.5 h, the CODE and TA removal rate of the system reached 89.2% and 71.6%, respectively.

A novel technology for quick acclimation of an anaerobic microbial consortia used for biodegrading teraphthalic acid (TA).

The seed sludge originated from a methane fermentation reactor was enriched and acclimated with TA as sole carbon source under nitrate respiration mode first for 6 week, and then can be turned to methane fermentation conditions. After 6 weeks processing, the specific rate of TA degradation under nitrate respiration mode reached 23.8 mgTA/(L.gVSS), more than two times of that under methane fermentation mode 11.4 mg TA/(L.gVSS). The TA reductive cleavers' population density increased about 6 times and 20 times after 30 days and 90 days acclimation. After a total of 90 days for the enrichment and acclimation, the fermentative bacteria which originally existed in the seed sludge nearly disappeared, and instead of them, the TA reductive and cleaving bacteria group was formed in the new consortia, which was confirmed by the MPN counts and roll tube counts. Compared with the control experiment, the acclimation period can be shortened by about 50%.