Liquid Oxygen Specification for Ozone Generation

摘要

Ozone is increasingly used in water treatment due to its unique ability to treat a wide range of water qualities. One of the largest operating expenses is liquid oxygen (LOX). In order to control costs, it is important that municipalities take advantage of the most economical LOX supply, but many municipalities are potentially limiting their choices by the way that they are specifying their LOX. Recently, AWWA revised B304-08 "Standard for Liquid Oxygen for Ozone Generation for Water, Wastewater, and Reclaimed Water Systems," which should help rectify this situation. In particular, the revision increases the acceptable level of Total Hydrocarbon (THC) from 25ppm to 40ppm. In many cases, however, this standard has yet to be adopted. This paper describes why THC level is important for ozone generation, what levels different municipalities are currently specifying, and why different air separation plants make LOX with different THC levels. It concludes by making recommendations for municipalities to ensure that they are getting LOX at the lowest cost that meets the quality required for reliable ozone generation.