Water industry embraces process optimisation

Tighter discharge consents are forcing the water industry to make further investments in wastewater treatment and this will increase costs and CO2 emissions. One of the main tools with which the industry can offset this effect is process optimisation, and Andy Thornton, a wastewater treatment specialist at Hach Lange, reports outstanding levels of success from plants across Britain that have implemented the company’s real-time monitoring and control system; W.T.O.S. (Wastewater Treatment Optimisation Solution).

Under the W.T.O.S. umbrella, the company has developed a range of Real Time Control (RTC) modules that can be applied to many of the most common treatment techniques. These currently include nitrification control in activated sludge, denitrification control, BAFF process control and cell management, sludge age control, chemical dosing control for phosphate removal, sludge thickening/polymer dosing control and dewatering control.

Each RTC is implemented on an industrial PC which communicates with a controller (sc1000) network and the local PLC. The W.T.O.S. RTC modules continuously deliver set points to the PLC, which applies them to the process and ensures that response to changing conditions is immediate.

Several of the initial W.T.O.S. systems have been operational for over two years and Andrew Thornton says “All of them are reporting very significant savings – 25% reduction in energy (electricity) consumption is not uncommon. This represents an enormous cost saving, whilst also helping to meet tighter consents and lower the plants’ carbon footprint.”