The Practical Application of Fine Time Increment, Diurnal, Nitrate Analyses Using Portable In Situ UV Spectrometers in an Effluent Dominated Urban Stream

0
- By:

Courtesy of Water Environment Federation (WEF)

 ABSTRACT

Many wastewater facilities use a nitrifying biological process to eliminate or reduce ammonia concentrations which are toxic to fauna in their receiving water. One byproduct of this process is nitrate. Nitrate is generally non-toxic to fauna in receiving streams at levels produced by a nitrification process. However, chronic exposures of 10mg/L NO3-N, or greater, may produce toxic responses in human infants. As a result, nitrate concentrations are regulated in waters that may impact drinking water sources. Some wastewater facilities are now being required to add an additional biological process to de-nitrify effluent. While there are a number of traditional methods for measuring nitrate in water, they are not suitable for on-going, rapid analysis of wastewater or environmental waters.

Because nitrate (and nitrite) in water absorbs UV light at a specific wavelength that has little interference, it can be used to estimate nitrate concentrations. I will discuss the principles of nitrate measurement using UV spectroscopy and the various instruments that are available in the market. I will also discuss the selection, modification and application of a small portable UV spectrometer. This instrument can be placed inconspicuously in any water body, without connection to the shore. The instrument typically measures nitrate every five minutes and can save a week’s worth of data for later analysis. Vital information is currently being collected on daily nitrate variation and patterns downstream from a wastewater plant; this information will be used to measure changes from baseline conditions when a major de-nitrification facility begins operation and can also provide an assessment of natural de-nitrification in a river system. The
instrument(s) can also be used by a wastewater treatment facility to evaluate the de-nitrification process at various stages.

KEYWORDS

Nitrate, UV, Denver, South Platte River, Analyses

Customer comments

No comments were found for The Practical Application of Fine Time Increment, Diurnal, Nitrate Analyses Using Portable In Situ UV Spectrometers in an Effluent Dominated Urban Stream. Be the first to comment!