Monitoring Nitrification Understanding the biological event Monitoring Nitrification

What is nitrification Biological process by which free ammonia is converted to nitrite and then nitrate. Free ammonia NH3 is converted to nitrite NO2 Nitrite NO2 is converted to nitrate NO3 These compounds are actually primary drinking water contaminates but at the Point of Entry (POE) of the system only Nitrite 1 ppm Nitrate 10 ppm

Why are we concerned with nitrification Creates unwanted byproducts Nitrite Nitrate Source of taste and odor complaints Consumption of disinfection Problems with Total coliform compliance Lead and copper Rule Compliance Microbial Induced Corrosion

Nitrification Precursors Food--- Ammonia Biology AOB or Ammonia oxidizing bacteria Nitrosomonas NOB or nitrite oxidizing bacteria Nitrobacter Disinfection or, more to the point Lack of disinfection

Where does the ammonia come from? Naturally occurring in ground water Run off in surface water Added to form chloramines Released from the chloramine in the system as a result of either biological demand for disinfection or decay of the chloramine molecule due to water age.

Source of AOB and NOB Nature Exists in biofilm in distribution lines Total coliform tests gives no direct read of AOB or NOB

What are we going to monitor? Total chlorine Monochloramine Free Chlorine ATP Biological indicator Nitrite Nitrate Free Ammonia Alkalinity ORP

How will the parameters move? At the beginning of the event Total and mono chlorine will start down Free ammonia can actually start to rise ATP will start up Free chlorine will remain very low Alkalinity and ORP will start to drop

As we go along Total and mono will continue to drop ATP will continue to rise Nitrite will start to appear Free ammonia will begin to drop Alkalinity and ORP will continue down

Full blown event Free, Total and Mono chloramine all but gone ATP can actually peak out and start to fall Free ammonia will fall Nitrite will continue to rise, peak out and then start to fall Nitrate will appear and start to rise Alkalinity and ORP an continue to drop

All generally speaking of course

Remember! We are monitoring a biological event If you depend on the residual drop, the event may have already started! If you depend on the appearance of the by products, the event is well advanced in it’s progress If you wait for the nitrate to appear……..well…..to late

Relevance of each parameter Any single parameter, used alone, is useless! Free and total chlorine are the easiest to run. Nitrite, free ammonia and monochloramine tend to get a little more time consuming depending on the method. Alkalinity and ORP are new tools in my arsenal

Biological Tools- Plate Counts Heterotrophic or other plate counts Traditional and been around a long time Time consuming. Several days to get results that have meaning Like coliform, are pretty much only going to find what they are looking for

ATP-Adenosine Tri Phosphate ATP is the energy carrying molecule in every cell By extracting and measuring the amount of ATP in a given sample you can quantify the level of total biological activity. This can be done in a matter of minutes either in the field or laboratory environment ATP technology is referenced in AWWA Manual M 56 as a protocol that is receiving increasing acceptance I use Luminltra Technologies, Fredericton, New Brunswick, Canada 2nd Generation ATP technology

All Parameters Considered Relying on the movement of any one parameter cannot tell you where you are in the event The whole process is biological. Thru ATP testing you can get an idea early on the trouble is coming and you can tell when you have recovered. Monitor a biological event with biological testing

Thank You Bill Travis btravis@tmbwater.com 985.974.0090