A common method to reduce TTHM and HAA formation is to utilize chloramines in lieu of free chlorine for secondary disinfection. Chloramines react less with dissolved organic carbon (DOC) and generally form less THMs and HAAs. However, Chloramines often create many unintended consequences due to nitrification. Chloramines are formed by adding ammonia with chlorine, thus adding nitrogenous microbial food that promotes bio-growth in water storage and distribution lines. Control of this “bio-reactor” process involves significant flushing to manage water age and periodic free chlorine “burn-outs” to reduce the microbial growth. The method to revert a water utility to free chlorine is to maximize DOC removal in the purification process. This is accomplished through Ultra-Coagulation, which is performed by a novel continuous ultrafiltration process utilizing ceramic membranes. The Ultra-coagulation process achieves significantly greater DOC and THM/HAA precursor removal versus traditional coagulation processes and allows water utilities that rely on chloramination to achieve DBP compliance to convert to much easier managed free chlorine.
This presentation is available to AMTA Members only.
- Steven Walden
- Purifics Water Inc.
- AMTA/AWWA Membrane Technology Conference, Las Vegas
- AMTA/AWWA Membrane Technology Conference
- DBP, Chlorine, Ceramic Membranes