Accession Number : ADA132114

Title :   Development of Efficient Ozone Disinfection Systems.

Descriptive Note : Annual rept. no. 1, 1 Oct 78-31 Sep 79,


Personal Author(s) : Chian,Edward S K ; Chang,Ker-Chi

PDF Url : ADA132114

Report Date : Jan 1980

Pagination or Media Count : 72

Abstract : The purpose of this study was to develop an efficient ozone disinfection system based on the concept that ozone inactivation of microorganisms occurs mainly at the gas-liquid interphases. This concept has previously been confirmed on a limited extent by the author and his co-workers. A logical approach to this work was to devise systems capable of generating a larger interfacial area by either physical or chemical means. The chemical method involved the addition of surface active agents whereas the physical method involved the use of motionless in-line mixers. Up to a one log-cycle improvement in ozone inactivation of E. coli was observed with the addition of 3 ppm of surface active agents in a clean water system. The effect of surface active agent addition on ozone disinfection was confirmed with the use of a secondary effluent. The effect of enchanced inactivation was, however, not as distinct as that obtained with a clean water system. Preliminary results obtained with a mechanical system employing Lightnin and Koch motionless mixers showed that the mechanical systems were not as efficient as the ozone sparged vessel in ozone disinfection of wastewater with or without surface active agent addition. A ten-fold increase in ozone disinfection was observed by using activated carbon treated secondary effluent with the motionless mixer system.

Descriptors :   *Ozone, *Disinfection, *Microorganisms, Efficiency, Inactivation, Escherichia coli

Subject Categories : Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE