SUBSTRATE REMOVAL IN LONG SEWER LINES

Wastewaters generated from large dwelling areas are collected and disp osed of by means of long sewer trunk lines. The wastewater treatment p otential of sewers is not a novel phenomenon, however, it has not been thoroughly investigated in the past. In this study, possible treatmen t efficiencies are estimated in the presence of sufficient oxygen. Sus pended and attached growth kinetics are studied to explore the signifi cance of aeration in sewer trunks. Although there are several existing models describing consumption mechanisms of soluble substrates and re action rates, a new method is investigated in this paper for shortenin g the parameters used in biological rate equations. Soluble substrate consumptions of suspended growth microorganisms are taken into conside ration by means of an experimental approach and they are estimated by using respiration rates. Relationships between respiration rate, subst rate utilization rate and biodegradable organic matter concentrations are observed during the experimental program. An empirical relationshi p which provides the utilization rate in correspondence with diminishi ng substrate concentrations along a sewer line is developed based upon the experimental results. Expected treatment efficiencies are determi ned considering utilization rates of attached and suspended growth mic roorganisms.