THE APPLICATIONS OF REAL TIME MONITORING AND MODELLING TECHNIQUES TO IMPROVE ENERGY EFFICIENCY IN WASTE-WATER TREATMENT
Pearce, M., Envitech Ltd., Cardiff, UK
(free)
Commercial pressures, together with CO2 emission legislation and tighter consents have
forced operators to seek ways of reducing energy use. Over 50% of energy consumption for
waste treatment may be attributed to ASP aeration. Tighter consents for BOD, NH3, NO3
and PO4, require the use of activated sludge and its variants to achieve the required effluent
quality. Hence it has become imperative to optimize operation of ASP’s. Great strides have
been made over the last thirty years, including progression from batch to continuous
process, surface aeration to diffused air, ceramic to membrane diffusers, in situ DO
measurement and control, low cost plc controllers and many others. More recent additions
are the development of reliable, low maintenance in situ instrumentation and their
application to minimising running costs. This paper concentrates on the application of a
variety of instruments including DO, NH3/NH4, NO3, organic strength, solids and settleability,
with a view to demonstrating how real time data from these machines may be used to
reduce energy consumption. The latest developments in linking real time data with a
dedicated real time modeling package are also described, and its advantages for further
cost savings demonstrated. Case studies of actual savings are detailed.
KEY WORDS
Energy Saving, activated sludge, Nitrification, denitrification, control systems, feedback,
feed forward, insitu instrumentation, dissolved oxygen, Ammonia, real time modeling,
optimization, load management, aeration capacity, Plug flow, complete mix, Sequencing
Batch Reactors, CO2 emission legislation
