Granular Activated Carbon Sequencing Batch Biofilm Reactor to Treat Problematic Wastewaters

Experiments were conducted to study the performance of a reactor packed with granular activated carbon, and operated in a sequencing fill and draw mode. The reactor was inoculated with micro-organisms, loaded with a solution of 3-chlorobenzoate and thioglycolic acid. Oxygen was transfered to the microorganisms by means of silicon rubber tubings embedded in the activated carbon bed. Comparative studies were conducted with a continuous flow activated carbon filter and with a reactor packed with sand instead of granular activated carbon. Periodic operation of the granular activated carbon reactor provided superior results. High substrate removal efficiency was achieved as was high process stability under shock loading conditions, the latter mainly as a result of intermediate adsorption and subsequent decrease of toxic effects. After a period of 14 months of continuous operation the activated carbon had maintained about 90 per cent of its adsorptive capacity.