Figure 1. Product Model Showing Process Followed in Developing Cardiff WwTW OptimisationABSTRACT: Aeration optimisation of a 16 basin SBR plant running in ICEAS (Intermittent Cycle Extended Aeration System) mode was undertaken by changing operating parameters from the traditional design of dissolved oxygen (DO) control to a scientific approach using respirometry. Measuring the critical oxygen point (COP) for carbonaceous and nitrification bacteria and combining this with in-situ Oxygen Uptake Rate measurements forms the basis of supplying only the correct levels of oxygen for the required amount of time to break down influent BOD and ammonia levels. These measures can be used to calculate when treatment is complete and therefore tailor energy requirements of the site to suit aeration supply needs. Resultant changes have led to sustainable operational savings of over 20% of aeration energy consumption and reducing carbon emissions whilst maintaining compliance.CARDIFF, Wales, UK, Sept. 30, 2009 -- This paper discusses an overall product model that combines a number of pieces of equipment, the expertise of scientists and consultancy support to optimise the aeration process of the activated sludge treatment plants of Cardiff & Afan Wastewater Treatment Works (WwTW), and initial investigations of other top energy sites. This was achieved using an innovative, cutting edge technology saving Giga Watt hours of energy and assisting Dwr Cymru Welsh Water (DCWW) and Kelda Water Services (Wales), or KWS(W), in reducing their carbon footprint. The scientific equipment used by the project was obtained from Strathkelvin Instruments along with its consultancy support working together with the KWS(W) Operations and scientific project teams to deliver savings.
Figure 6. An Example of a Biodegradation Profile in Winter Flow Mode
Figure 11. Annual Percentage Energy and Carbon emissions