Practical Design Aspects of an Immobilized-Cell Denitrification Process

摘要

Groundwater contaminated with high levels of nitrate represents a potential health risk when used as a drinking water source. Nitrate-bearing groundwaters are common in areas of intensive agriculture. The most common methods for removing nitrate from a drinking water source are ion exchange, reverse osmosis, and biodenitrification. Among these, biodenitrification offers a means of nitrate removal without generating a concentrated brine waste. However, biodenitrification plants employing suspended or attached growth treatment systems normally require a lengthy start-up time and are subject to operational failures because of fluctuating treatment conditions. This research elaborates an entrapped microbial denitrification process that is particularly appropriate for small systems. The technology was based on entrapping denitrifying microorganisms inside a carrier that served as a physical enclosure for cell retention. The feasibility of utilizing entrapped microbial technology was demonstrated based on experimental results of nitrate removal from groundwater supplies and regenerant or brine wastes. Design diagrams and methodologies have been developed.