Technically Speaking: Grit Removal
Grit entering the process stream of a wastewater treatment works has always posed a threat by raising operating costs and impacting on energy efficiency. But the heavy burden in energy, materials, time and money is widely tolerated in UK water companies because it is accepted as unavoidable.
Whether a primary tank or digester needs cleaning out, a sludge pump stripping down, or aerators need unclogging, it is accepted as something that has to be done.
Until now, most wastewater treatment operators in the UK have lived with a compromise, a “one size fits all” approach to keeping their grit nuisance at bay at the inlet works. By accepting this norm, many simply do not know how much grit they are missing.
Now, our attitudes to grit are changing and the realisation of the true cost of grit – especially finer grit- has started to undermine this stance. Utilities are considering the total cost of capital and operating expenditure (total expenditure, or TOTEX) in their investment decisions, so asset managers, operations staff and maintenance engineers no longer have to put up with grit.
Read Keith Hutchings' full article Technically Speaking: Grit removal at wwtonline.co.uk.