Biological wastewater treatment is an economical means of removing both organic and inorganic contaminants from wastewater. While it is commonly used for the treatment of domestic sanitary wastewater, it is also effective for industrial wastes. Biological treatment systems can be aerobic, anoxic, anaerobic, or a combination depending on the application and treatment goals. Technologies are further classified as attached growth biological processes, such as rotating biological contactors and SeHAWK®, or suspended growth such as, the ADI Sequencing Batch Reactor.
The first step in a wastewater treatment process utilizes primary or mechanical systems to remove large suspended and floating solids from raw sewage. In the next step, called secondary or biological wastewater treatment, high concentrations of naturally occurring bacteria are confined in treatment tankage and combined with protozoa and other microbes to form activated sludge. The activated sludge bacteria break down organic molecules into inert substances creating effluent water suitable for discharge to rivers, lakes or streams.
As effluent water quality regulations become more stringent, the demand for high quality wastewater treatment solutions continues to grow along with methods for reducing energy consumption and expanding capacity in existing plant footprints. Evoqua responds to evolving wastewater treatment standards with solutions that include biological oxygen demand (BOD) reduction, aeration, clarification, phosphorous and nitrogen removal. We also offer key innovations for simultaneous nitrification denitrification, magnetite ballasted treatment, and biological treatment for trace contaminants such as selenium and heavy metals.
In addition, when plant treatment equipment reaches the end of their useful life, Evoqua can help turn what you have into what you need, to increase performance, reduce maintenance and extend lifetime to keep treatment plants up and running.  Increased performance, water reuse and energy savings contribute to sustainability, which is why biological wastewater treatment is part of our renewable energy portfolio. Click here to learn more.
