Summary of the technology
This control system allows optimization of the activated sludge process since maintains effluent nitrogen concentration under limit values with minimum energy consumption.
The most remarkable advantages provided by this technology are:
Cost reduction of initial investment and maintenance
Easier operation than nutrient analysers
Lower time response
Lower aireation energy consumption
Lower pumping energy consumption
Description of the tech for sale
Control systems implemented on wastewater treatment plants (WWTPs) may be able not only to accomplish more rigorous effluent standards but also to minimize energy consumption associated to the process. Nowadays, control systems in WWTPs with biological nitrogen removal are mainly based on on-line nitrogen analyzers that measure ammonium and nitrate concentrations in the anoxic and oxic zones of the treatment process. This kind of instrumentation involves a significant acquisition and maintenance cost because of the complexity of necessary equipment. Furthermore, a continuous supervision from plant operators becomes necessary. Researchers from the Universitat de València and the Universitat Politècnica de València have developed a control system based on fuzzy logic for continuous WWTPs with biological nitrogen removal using low-cost sensors such as pH and ORP sensors. This control system maintains effluent nitrogen concentration under limit values with less energy than control systems based on on-line nitrogen analyzers.
The control system is composed of two independent controllers for nitrification and denitrification processes respectively: • A nitrification process controller acts over concentration of dissolved oxygen of the aerobic reactor allowing increase said concentration when necessary for ammonium removal. • A denitrification process controller acts over the internal recirculation flow from aerobic to anoxic reactor allowing increase said flow when the process has the capacity for denitrificate de nitrate from this recirculation. pH and ORP measurements give valuable information for applying fuzzy logic-based controllers. This control system let optimize the activated sludge process since maintains effluent nitrogen concentration under limit values with lower energy consumption. Moreover, with the obtained results, aeration and dumping energy consumption are optimized.
Main advantages of its use
- This technology involves lower initial investment and lower maintenance and operational costs for the control system, by replacing commonly used ammonium and nitrate sensors with low cost sensors. Besides, low cost sensors have the additional advantage of their easy usage and lower time response.
- The main application of the technology is in wastewater treatment plants, since it is a biological nitrogen removal control system that can be applied in WWTPs with continuous systems with either plug flow reactor or completely mixed reactors.