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Determination of permissible industrial pollution load at a municipal wastewater treatment plant
Mikosz, J.
Abstract
Industrial wastewater discharged to a municipal
sewage system may often be a source of valuable organic
substrate for biological processes at a municipal wastewater
treatment plant (WWTP). In such situations, the pretreatment
of wastewater at an industrial plant should be
minimized, in order to maintain the favourable structure of
organic material in influent to a WWTP. A frequent
problem is how to determine the maximum industrial
pollution load that can be discharged, without compromising
the treatment capability of a WWTP. This article
presents a method based on computer simulation that can
be used for this purpose. As a result, the method produced
the permissible industrial pollution load that could be discharged
safely, and the relationship between chemical
oxygen demand (COD) load and required biomass concentration
as a function of process temperature. The
method was tested at a fruit-processing plant and municipal
WWTP, located in Poland. The results of this study have
shown that the bioreactor should be operated at a biomass
concentration varying between 3,600 and 5,400 g m-3 in
function of the process temperature. Under such operational
conditions, the WWTP would be able to accept the
permissible industrial COD load of above 9,000 kg
COD d-1 for a wide range of temperatures, namely
14–19 °C. If the WWTP was operated at a constant biomass
concentration, its permissible industrial COD load
would be reduced to 7,500–9,000 kg COD d-1. The
method can be applied to other municipal WWTPs with
activated sludge that receive industrial effluents.
Keywords
Industrial wastewater; Wastewater treatment plant; Activated sludge; Nutrient removal; Modelling; Computer simulation
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