Water & Wastewater Treatment

8 | JANUARY 2015 | WWT | www.wwtonline.co.uk Comment A MP 6 is set to be the Asset Management Period where the Water Companies are challenged to make the industry run more efficiently: it is set to be the period where the capi- tal solution is not thought of as the first thing to build, but a more holistic approach is taken, and all options are considered. In short, it is the start of a big challenge to the water industry to operate differently, smarter, more efficiently than it has done in the past. There is an opportunity for instrumentation to form a part of the solution. This was the focus of the recent Sensors for Water Interest Group Work- shop on "Instrumentation for TOTEX Efficiencies in Wastewater." The subject of the presentations centred around three main themes: • Producing energy and protecting the as- sets that are part of the energy production process. • Reducing the energy that is used using instrumentation as the basis of control systems. • The use of control systems to provide better operational control of the treatment works. Where instrumentation meets TOTEX The swing towards TOTEX in AMP6 should provide the right environment for water companies to invest in instruments that can protect and optimise assets and energy use The theme around producing the energy starts with the operational control of the treatment works. For example, the workshop saw a presenta- tion about the desludging of primary tanks to get the maximum benefit from the sludge, the main indigenous energy source on site. Another covered how to protect digesters by the analysis of inhibi- tory substances, and protect the Combined Heat & Power engines by the measurement of Siloxanes. Some startling savings can be made if instru- mentation is used to either protect the process or optimise the way the industry operates. Taking a holistic approach - maximising the products that the industry can take from the wastewater treatment plants, including energy & biosolids - is going to be a fundamental growth area in the water industry. The measurement of the product, something the industry has not neces- sarily been very good at, is vital to maximising the outputs from this particular area of the business. The second theme is something that the industry has got very good at, and that has been the reduction of the energy that the industry uses. The particular presentation at the workshop was around the use of organic load control to minimise the aeration that is used in the Activated Sludge process. There are in fact many suppliers who can provide either organic load control or nitrifica- tion control, and there are gains to be made: the figure that is usually touted is between 50-70% of the wastewater power consumption. What I o"en feel is missing is sludge age control, which should come hand-in-hand with any of these energy reduction techniques, and has the additional benefit of managing sludge stocks. However, the instrumentation is present, the control systems are there, and they have been implemented by at least some of the water & sewerage companies - the economics are plain for all to see. The last theme is the use of control systems for better operational control of at least part, if not the entire, treatment works. In fact most of these systems can actually be classed as advanced process control systems, using either instrumental or multivariate techniques to imply the operational state of the treatment works. In this, not only can the economic efficiency of the consumables on the treatment works be reduced, they can also be tracked and the amount of potential "savings" or "losses" be used to highlight the implications of a way of operation. The fundamental basis for this is of course instrumentation & control. During the day, there were numerous discus- sions amongst the gathered audience about the understanding of TOTEX and the swing from capi- tal to operational solutions with the bias towards building capital solutions now disappearing and a level playing field being set. This should hopefully allow the greater use of instrumentation to inform decision making and ways of working in the water industry moving forward. Oliver Grievson is Flow Compliance & Regulatory Efficiency Manager at Anglian Water and a director of the Sensors for Water Interest Group (SWIG), a not for profit, knowledge-exchange and network- ing group with a diverse UK-wide membership. Info: www.swig.org.uk Oliver GrievsOn DIRECTOR, SENSORS FOR WATER INTEREST GROUP (SWIG)

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