Waste Water Applications

Wastewater

The Proteus is the ideal sensor platform for monitoring organic loading in the sewerage network and at all stages of the waste water treatment process. Using robust and rigorously tested algorithms the Proteus provides accurate, real-time, quantification of BOD and COD concentration. The sensor platform is reagent free and maintenance requirements are minimal due to the automatic wiper and low drift, digital sensors. Whether you require on-line BOD monitoring of final effluent to ensure compliance or are seeking to improve efficiency of the treatment process using feedback and control loops for settlement and aeration, the Proteus is the instrument for the job.

BOD - why is it important?

Biochemical Oxygen Demand is a very important water quality parameter within the wastewater industry and in particular the WWTW. BOD is the measurement of the ammount of dissolved oxygen that is used by aerobic micro-organisms to decompose the organic matter in water. A typical healthy river will have 100% saturation of oxygen (8-10mg/l), hence lots of oxygen for micro-organisms to cosume organic matter. However, incoming wastewater to a WWTW is likely to have less than 10-20% saturation or 1-2mg/l of dissolved oxygen. This reduced amount of oxygen is not enough to feed the bugs to decompose the organic matter. As such the dissolved oxygen levels must be increased dramatically by the use of aerators for the bugs to do their job.

BOD5 - shouldn’t we move on?

The BOD5 (5-Day Biochemical Oxygen Demand) test is widely accepted as not being a precise quantitative test. The lack of technological advancement has meant that this 100-year old test is still used today even though it is not very accurate. BOD5 is typically used to enforce compliance limits on discharges from WWTWs in most countries. Water companies and industrial effluent dischargers must always operate below their discharge consent limit or risk prosecution. We regularly hear or read in the news about pollution events from WWTWs, Combined Sewer Overflows (CSOs) and industrial companies but to date there has been no real-time BOD sensor available. This has meant that organisations have to rely on less reliable surrogate parameters or rely on the occasional spot sample which is sent off to an accredited laboratory. Regulations for BOD vary across the world but typically discharges have to be below 15mg/l. The maximum BOD discharge into sewer systems varies between 200-300mg/l.

Ensuring Compliance...

If a result comes back over compliance it is simply too late and the damage to the environment is done. If the rate of DO consumption by bacteria in the receiving waters exceeds the supply of DO from the aquatic plants, algal photosynthesis or from natural aeration then stress is applied to the aquatic environment. Excessive stress can decimate aquatic ecosystems.
If an organisation or water company has exceeded their consent limit this ultimately means that the upstream treatment processes are not working effectively. The Proteus is the ideal sensor platform for monitoring organic loading in the sewerage network and at all stages of the waste water treatment process. Using robust and rigorously tested algorithms the Proteus provides accurate, real-time, quantification of BOD and COD concentration. The sensor platform is reagent free, requires minimal maintenance due to its automatic wiper, low signal drift and digital sensors. Whether you require on-line BOD monitoring of final effluent to ensure compliance or are seeking to improve efficiency of the treatment process using feedback and control loops for settlement and aeration, the Proteus is the instrument for the job.

Proteus - precise monitoring & control

The Proteus can be utilised at various stages in the WWTW process; it can be used to measure initial load post screen; it can be deployed after the primary settlement tanks (PSTs); it can be deployed prio to aeration lanes to provide precise aeration control; and it can be used to ensure compliance at the discharge point. A typical WWTW has very little control but with the use of the Proteus it is now possible to instill some intelligence into the WWTW process and additionally guarantee environmental compliance.