As more and more governing bodies and authorities are coming up with stringent discharge standards related to nutrient and organic pollution from municipal as well as industrial wastewater treatment plants, there have been an increased demand in upgradation of existing wastewater treatment plant for meeting these new standards as most of the plants are basically designed for the removal of organic pollution only.
Traditionally, existing Conventional Activated Sludge (CAS) system can be upgraded for higher flows and Nutrient removal configuration by adding additional volume of aeration tanks and clarifiers to the treatment train. However, due to scarcity of land availability in urban areas and also due to financial restrictions, this traditional solution might not help a lot to achieve treatment goals.
One of the economical and efficient solution would be to convert the existing CAS in to Integrated Fixed Film Activated Sludge (IFAS) system which requires addition of fixed or floating media within aeration basins. The addition of media allows for growth of immobilized biomass in the system and thus increase the MCRT of the hybrid system providing more treatment capacity for BOD removal as well as for nitrification of nitrogenous pollutants.
Converting existing CAS to IFAS has many benefits which includes:
- No additional land required
- Process flow sheet of the plant remain same and thus major hydraulic as well as civil reshuffle could be avoided.
- Solids loading to clarifier is not increased with increased treatment capacity and thus same clarifier could be utilized for higher capacity.
- Improved solids removal due to improvement in the SVI values because of hybrid biomass growth.
- Simultaneous Nitrification and Denitrification also feasible allowing for lower nitrate recycle ratios for achieving lower Total Nitrogen (TN) concentration in the final treated effluent.
- Most of the existing infrastructure can be employed without putting excessive burden on the total cost of upgrading existing plant.
- Not much major shift in the operational practices and thus operators can be trained effectively to handle new system.
LEVAPOR Carriers are first synthetically modified PU foam based carriers impregnated with activated carbon to provide optimal properties required in a carrier media for microbial cell immobilization. Using Levapor carriers existing CAS can be upgraded for higher flows, better COD reduction for reuse and recycle and Nitrogen removal. Due to their specific properties LEVAPOR carriers offer many advantages over conventional plastic and fixed in place media based IFAS systems:
- Lower degree of reactor filling (12-15%)
- Faster colonization and rapid process start up and stabilization
- lower energy consumption for fluidization and mixing
- Simultaneous Nitrification and Denitrification reducing Nitrate recycle requirement to much economical levels.
Our 20 MLD NINGAN, China installation is an example of upgradation of existing 10 MLD Oxidation Ditch Pond designed for BOD removal only to achieve Chinese Class 1 criteria of BOD/TSS/TN < 15 ppm . The plant is under operation since 2010 and consistently meeting above standards.
We provide complete process design , basic engineering and pilot testing services to our clients for their existing wastewater treatment plant upgradation requirement.
Contact us for more information.