Response of Completely Mixed Systems to Hydraulic Shock Loads

Responses of completely mixed, once-through continuous culture systems of heterogeneous microbial populations of sewage origin were systematically examined under two conditions of hydraulic shock loading. Eight experiments were conducted with constant concentration of inflowing feed carbon source, and eight under conditions of constant daily organic loading rate. Biochemical response was assessed primarily by measurements of biological solids concentration and effluent concentration of carbon source. It was found that under conditions of constant feed concentration, increases in flow rate were most detrimental and an increase of up to 100% could be accommodated without serious disruption of biochemical efficiency. Under constant organic loading conditions, decreases in flow rate were more detrimental and a decrease of 100% could be accommodated without serious transient disruption.