A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1988

Biocarbone Filter Process has been conducted, the two units of 15 cm diameter and 1.40 m height laboratory scales were packed with 0 .74 mm activated carbon, 2 .00 mm anthracite and 4.00 mm gravel media. The A.I.T. raw sewage was used after 1 h settling, the following characteristics were found pH 7.6, turbidity 30 NTU, 0.090 mg/l SS, 144 mg/l COD, 67 mg/l BOD5 , 0.03 mg/l N02 -N, 0.12 mg/l N0 3 -N, 10 mg/l NH 3 -N, 5 mg/l Org-N, 13 mg/l TKN and TN, 2.0 mg/l Ortho-P and 2.3 mg/l T-P respective l y . The BOD:N:P ratio was about 30:6:1. The 1 h sedimented A. I . T. raw sewage was fed to the reactor by semi-continuous feed with the hydraulic loading rate of 20-t~o m3 /m2 {u2022} d similar to the values for activated sludge and trickling filter processes. The optimum hydraulic loading rate was found at 35. 34 m3 /m2 {u2022} d. The optimum applied air flowr ate was 0. 50 l/min at STP which was equivalent to DO of 5-7 mg/l. This process consumed 10-15 minutes hydraulic detention time. The expansion portion had no effect on the reactor performance. The biocarbon media depth had effect to nitrogen content but not proportional For downflow biocarbone process using 0.74 mm activated carbon as a medium, removal of 85-90% COD and BOD5 , 65% of TKN and 40-50% of T-P was achieved respectively. The activated carbon adsorption was 0.15 mg COD/g AC. The effluent COD and BOD5 values were 10-30 mg/ 1 and 20 mg/ 1 respectively. For downflow biocarbone process using 2.00 mm anthracite media, 85% of COD and BOD5 , 65% of TKN and 40% of T-P were removed. Anthracite media was found to be more stable configuration, better color adsorption capacity and well suspension performance.