Design Loading of the AdvanTex® Packed Bed Reactor
Biochemical Oxygen Demand
Among other factors, the treatment performance of the AdvanTex® packed-bed reactor is a function of the biological and hydraulic loading rates applied to the textile medium per m². This has been confirmed by third party ANSI (American National Standards Institute) and NSF (National Sanitation Foundation) testing. This loading rate is based on a 30-day average flow rate. The filter can accommodate a peak flow rate (sustained for short periods) double the average flow, corresponding to a loading rate of around 2,000 mm per day and still achieve this treatment performance.
For biological mass loading of the system, the AdvanTex® is sized on a mass loading of 1.81 kg BOD/AX100/Day for average flows and is capable of twice the mass loading for short periods (i.e. 3.62 kg BOD) to achieve an effluent quality of 10 mg/l BOD5. The short periods would include peak periods of 4 to 6 weeks without adversely affecting effluent quality. For design purposes, we use a value of 200 mg/l BOD discharging from the interceptor tanks. This considered conservative since the effluent BOD used for these calculations is relatively high for a STEP scheme. Empirically the value is closer to 130 mg/l BOD5.