Poster Presentation 1B-09

Reclamation of Petroleum-Based Wastewater by a Novel Ozone Immobilized Biological Activated Carbon Process

F. Ma¹, S.Y. Qing¹, P. Huang¹, S.N. Sin¹, N.Q. Ren¹ and H. Chua^2*

¹School of Municipal and Environmental Engineering

²Joint Research Centre for Water and Wastewater Treatment Technology

Department of Civil and Structural Engineering

Hong Kong Polytechnic University

Hong Kong, China

Wastewater reclamation in the petroleum industries in Northern China is important because shortage of water resources is a severe problem. Conventional treatment technology used in treating petroleum-based wastewater, namely the 3-phase biological process, typically removes COD, BID, grease, volatile hydrobenzenes, cyanides, sulfides and suspended solids. However, the process is often ineffective in ammonia-nitrogen removal, and thus the treated effluent often falls short for the required standards for re-use. This paper investigates a novel ozone immobilized biological activated carbon (O₃-IBAC) process for ammonia nitrogen removal from petroleum-based wastewater. Operated at a hydraulic retention time of 10 minutes, the O₃-IBAC process achieved ammonia nitrogen removal efficiency of 91 %. In addition, the removal efficiencies of COD, volatile hydrobenzenes, suspended solids, turbidity and petroleum-based micro-pollutants were all above 90 %. Competition between the autotrophs and heterotrophs was observed, which was indicated by an increase of ammonia nitrogen removal with a decrease of COD removal, and vise versa. Pollutant reduction in the IBAC process was achieved by a rapid physical adsorption on the activated carbon, which effectively retained the pollutants in the system despite the short hydraulic retention time. Nitrous acid was observed to accumulate in the nitrification process when the operational pH was increased to 8 or above, operational temperature was higher than 30^oC and the hydraulic retention time was shorter than 10 minutes.