Carbonaceous oxidation using a new vertically moving biofilm system

This laboratory study consisted of the construction and testing of a new ex perimental biofilm system for the carbonaceous oxidation of a synthetic was tewater. In the system, a biofilm cuboid module with a high surface area wa s vertically and repeatedly immersed in and lifted out of the wastewater in a reactor. The performance of two different biofilm modules were compared: one module was constructed from crossflow corrugated plastic sheets with a specific surface area of 410 m(2)m(-3) and had a calculated surface area o f 6.24 m(2) the other consisted Of honeycombed plastic with hexagonal verti cal columns and an estimated surface area of about 2.8 m(2). Filtered chemi cal oxygen demand (COD) removal rates per bull; fluid volume for the corrug ated and honeycombed modules of 7.2 kg COD m(-3) d(-1) and 7.6 kg COD m(-3) d(-1) were respectively achieved and these rates compare favourably with o ther wastewater treatment systems. The new biofilm system was simple to con struct and operate, and was very effective in removing biodegradable COD fr om the synthetic wastewater. The system offers potential for reduced reacto r volumes, energy saving, low solids production and easy solids removal.