Abstract
The present study evaluated the effectiveness and durability of TDR for biofilm development and related long term usage in fixed biofilm reactors for wastewater treatment. TDR incubated (30±2ºC) with activated sludge showed comparatively higher biofilm development (0.51g) under aerobic than under anaerobic (0. 42g) conditions after 7 weeks. During biofilm succession, a significant shift in bacterial community was observed from pathogenic to autotrophic after 4 weeks. The decreasing bacterial count (MPN index) ( 80%) (E .coli and feacal coliforms) and COD, and BOD (70% approx.) depicted diminishing organic load in sludge. While, changes in pH and nutrients like NO2-, NO3-, PO43-and SO32- indicated presence of other key-bacterial species with efficient nutrient consuming abilities in biofilm. Scanning Electron Microscopy showed few aberration and rich bacterial growth on treated TDR. Furthermore, detailed analysis through FTIR spectroscopy confirmed minor transformation in TDR under anaerobic conditions. TDR proved to be considerably durable and cost effective support material that can be used in aerobic fixed biofilm reactors for wastewater treatment. However, operational conditions of the reactor should be optimized to keep the biofilm structure intact and for achieving desired wastewater treatment efficiency.