Presentation on theme: "GENERATION OF ADDITIONAL REVENUE FROM PRODUCTS OF"— Presentation transcript:
1 GENERATION OF ADDITIONAL REVENUE FROM PRODUCTS OF POTENTIAL FORGENERATION OF ADDITIONAL REVENUE FROM PRODUCTS OFWASTEWATER TREATMENTDr. Damjan Nemec (B.Sc.Chem.Eng.)
2 Wastewater treatment in general Process of removing contaminants from collected sewageHousehold sewageIndustrial sewageNature of contaminants:physical (TSS)chemical (COD)biological (BOD)Objective is to produce an environmentally-safe effluent
3 Wastewater treatment in general Basic process stepsUsually regarded as the black sheep of utility servicesHigh operating costs and rarely appreciated by the publicPreliminary(physical)ScreeningGrit removalGrease removalEfficiency:- TSS = %- COD = %- BOD = - 5%Primary(physical, chem.)SedimentationEfficiency:- TSS = %- COD = -20%- BOD = -20%Secondary(biological)AerationSedimentationEfficiency:- TSS = %- COD = -90%- BOD = -95%Tertiary(advanced)Nutrient removalFiltrationAdsorptionDisinfectionEfficiency:- TSS > %- COD > -99%- BOD > -99%
13 Expanding services Biogas plant has space for additional substrate Food waste from hotels can be collected as extra service~100 hotels, ~6.500 tourists~0,5 kg of food waste per tourist => 3,5 t/d of energy rich waste
14 Biogas production from sludge SubstrateFood wasteBiogas storageFlareCHP unitDigester #1Digester #2BiogasBiogasBiogas cleaning
15 Biogas production from Kipevu WWTP sludge Nett production of electricity= kWh/dkWh/a × 20 KSh/kWh = KSh/d (47%)Overall investment€ (~ 4,8 years of payback)37% less sludge to dispose!
17 Reuse of treated water from WWTP Can be treated further with advanced methods and reused:Urban reuse:Irrigation of public parks, landscapes and golf coursesVehicle washing and decorative water featuresConnecting to fire hydrants for fire protectionIndustrial reuse:Cooling waterBoiler make-up waterIndustrial process waterAgricultural reuseCan even be purified to potable water standards!
18 Reuse of treated water from Kizingo WWTP For irrigation of the golf course and local parksOnly filtration and disinfection requiredNutrient removal not required, their presence is beneficial!Limited extra investmentPlant is located beneath the golf course!
19 Reuse of treated water from Kipevu WWTP After treatment the water is discharged into the seam3/dFocus on cooling water requirements of the local industryUsually the largest use of reclaimed waterHigh quantities and moderate quality requiredNumerous petroleum refineries in the US that practice this
21 Reuse of treated water from Kipevu WWTP Potential treatment required for cooling water standardCorrosion concerns (filtration)Removal of dissolved solidsBiological concerns (disinfection)Removal of microbiological organisms (may deposit on surface)Removal of nutrients (may contribute to microorganism growth)Scaling concerns (chemical treatment)Removal of Calcium, Magnesium, Phosphate and Sulphate
22 Current conclusions Wastewater treatment… …is required to protect the environment (for today and tomorrow)…can be very expensive, especially if plants are under capacity…plants should be maintained regularly with skilled staffThe cost pressure can be reduced……by “exploiting” the potential of wastewater treatment productsSludge for energy (biogas)Expanding the services to collecting other energy rich waste (tipping fees)Reuse of treated water will be gaining in importance in the coming yearsConcrete results on the assessment will be made available