water on-site and in real time is straightforward with the use of Real Tech’s nitrate analyzers. Nitrates have a characteristic absorbance curve in the UV region which makes them an excellent candidate for detection by spectrophotometry. However, organic compounds, nitrites, iron, manganese and suspended solids also absorb UV light and interfere with nitrate detection. To compensate for these potential interferences, Real Tech’s nitrate analyzers are equipped with proprietary algorithms that use absorbance information from strategically selected wavelengths of light. In addition, the Real Clean automatic cleaning system ensures that the sensor is kept free of fouling and drift. This saves time and labour as manual cleaning and calibration are not typically required, while accurate readings are maintained. One water utility, that provides groundwater to residents from hundreds of wells in a rural area, requires online monitoring to ensure that nitrate levels are maintained in compliance with drinking water regulations. Some of the wells have high nitrate concentrations in the water, while others do not. The water utility manages this situation by blending waters from clean wells with nitrate contaminated wells to ensure that the finished product water has nitrate levels well below the regulatory limit of 10 mg/L NO3 as N. Before the treated water is pumped into the distribution network, it is monitored for pH, residual chlorine and nitrates. Real time monitoring is a much needed decision-making tool for this utility as it provides the required water quality information within minutes and allows for immediate action to protect the public from exposure to high levels of nitrate in their drinking water. The utility participated in a four month study of Real Tech’s nitrate analyzer, to test accuracy and demonstrate the effect of fouling. Results showed it maintained a steady baseline close to 0 mg/L, thanks to the automatic cleaning system, and was able to accurately report nitrate events.
www.esemag.com
CONCLUSIONS Real time monitoring is an excellent tool for ensuring public safety by providing vital information in a timely manner. It provides data, both spatially and temporally, by continuously analyzing the water on-site, as opposed to laboratory testing methods which analyze small volumes that are widely spread over time. This allows for better
trend and event monitoring, optimizing the decision-making processes. Finally, real time monitoring can be used for optimizing the water blending process, saving energy and costs in water stressed regions. Kerim Kollu, PhD, is with Real Tech Water. Email: kerim@realtechwater.com
THE
SYSTEM FOR HDPE PIPE
THE FASTEST WAY TO JOIN HDPE PIPE — NO IFS, ANDS, OR BUTTS.
refuse-to-fuse.com © 2017 VICTAULIC COMPANY. ALL RIGHTS RESERVED.
February 2017 | 51