A QUESTIONNAIRE FOR DESIGN OF SSI AERATION SYSTEM   *Name : Date : *Contact Tel : Offer needed within : *Address : Name of the project    *Type of treatment process (activated sludge, extended aeration, SBR etc)     *Type of waste water (municipal, industrial/ what industry?)     *Average daily flow (㎥/day) *Peak daily flow (㎥/day) *BOD₅ in (mg/l)  after pretreatment (wastewater to the aeration tank) *BOD₅ out (mg/l)  effluent *Aeration tank dimensions (layout sketch)   Number of tanks   Parallel or in a train   Water depth (m)   (Please note that it is water depth not tank depth)   Length and width of each tank (m) Process temperature (℃) (temperature of wastewater in an aeration tank) (Normally not more than 35℃) Altitude from the sea level (m) (no need to give if less than 100 m ) MLSS or MLVSS (mg/l) (MLVSS = 0.8xMLSS, normally MLSS = 3,000-4,000 mg/l) DO (dissolved oxygen), mg/l in aeration tank (normally 2mg/l) Nitrification? (NH₄ -H in and out), mg/l Dentrification? (Total N in effluent), mg/l Type of aeration systems needed :         Fine Bubble Disc Diffuser     Fine Bubble Tube Diffuser     Coarse Bubble Diffuser     Fixed Grid on tank bottom     Retrievable / Liftable