Abstract:
The aim of the study was to evaluate the anoxic-oxic reactor performance in synthetic textile
wastewater treatment and its effluents application for irrigation purposes. The anoxic-oxic
reactors were inoculated with 10% microbial consortium and raw simulated textile
wastewater was allowed to flow under controlled conditions. When the OLR, dye
concentration and HRTs were 0.7 Kg/m3
d, 200 mg/L and 48 h, respectively the system
performed maximum removal of 98.83% dye, 97.42 % BOD, 96.30% COD, 77.51% TN and
76.19% TPO4. At the higher OLR (0.7 kg/m3
d) and HRT (48 h) conditions, maximum RR dye
removal efficiency of 81.16% was achieved by anoxic than oxic (8.99%) reactor which might
be due to the biomass adaptations to use the cleaved dye bonds as an electron acceptor. The
lower oxic performance was resulted from the higher DO (average 3.70 mg/L) in the reactor
in which the biomass utilizes more organic matter rather the dye molecules. Unlike dye
removal, the removal efficiencies of COD and BOD in the oxic reactor are higher (83.16 and
88.54%, respectively) than anoxic (78.10 and 77.46%) since the microbes use the available
DO as a final electron acceptor in degrading the organic waste. An attempt was made to
isolate and characterize the anoxic-oxic activated sludge and the result revealed that the type
and number of biodegrading organisms were higher in anoxic than oxic reactor. In the
present study, the effluent was evaluated for their relative toxicity by irrigating commercially
edible crops. Both influent and effluent irrigation significantly affected the germination rate
of evaluated crop seeds. Furthermore, the effluent irrigation has showed alterations in
morphological and biochemical characteristics of experimental crops. Finally, it was
depicted that a system was found to be valuable to scale up at pilot level.
