Can we Minimize Biosolids Production in Activated Slduge Systems by Process Manipulations-Process Sustainability and Nutrient Removal

Urbanization and industrialization have led to increase in the number of wastewater treatment plants and the quantity of wastewater to be treated. Activated sludge process is the most widely used treatment technology to remove biodegradable organic compounds in municipal wastewater treatment plants. Excess biomass generated in the activated sludge is one of the main drawbacks using biological treatment processes (Goel and Noguera, 2006; Novak et al., 2007; Datta et al., 2009). These efforts have shown a reduction in the biomass by applying a feasting and fasting concept with synthetic wastewater. A recent study (Datta et al., 2009) reported the possibility of nutrient removal in activated sludge process when it was operated under a fasting and feasting mode. However, almost all of the aforementioned efforts used synthetic wastewater to demonstrate proof of concept. In this manuscript, we report the response of a sludge minimizing laboratory scale reactor when the operation is switched from synthetic feed to the real primary effluent collected from a local wastewater treatment plant. This is the first study to show how nutrient removal and sludge minimization efficiencies are affected by changing feeding solution from synthetic to the wastewater primary effluent using a sequencing batch reactor (SBR) operated in simultaneous sludge minimization and nutrient removal mode. The results showmore than 80% PO43-P removal and 98% NH3-N removal efficiency and 38% biomass reduction when operated at 100 % real primary effluent in comparison to a similar control SBR operated in conventional activated sludge more.