Communications mation and orientation of the polymers due to the flow are not high enough to demonstrate the birefringence effect. AcknowledgementsThe authors would like to thank the University of Essen and the MWF for financial support throughout the course of this project. The company BASF AG, Ludwigshafen, supplied the polymer Sedipur and the company NRC GmbH, Hamburg, supplied the polymer Nordfloc used in this work. A corona discharge reactor consisting of a hollow needle cathode and a net anode was used to remove benzene, toluene, and chlorobenzene in a synthetic air stream. Two gas flow directions were adopted to examine the contributions of the separated reaction zones, a high-energy corona zone at the needle cathode tip and a relatively large zone outside it. The target gas was fed in the corona zone through the needle cathode and exhausted through the net anode. Inversely, the gas was fed in through the net anode and exhausted through the needle cathode. It was observed that the removal efficiency of these components did not depend on the gas flow directions, indicating that the spatial distribution of the reactivity was not influential on the removal efficiency of the three target gas species. This means that the high electric field zone around the needle cathode tip would overwhelm the surrounding low-energy zone. In addition, the contribution of ozone reaction was observed as insignificant. Considering a reported ozone distribution, this result also indicates that the main reactive zone is the corona zone at the cathode tip.