RFICs

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  • infowater-pro
    InfoWater Pro

    Engineers use Autodesk InfoWater® Pro software to model water distribution systems in an easy-to-use GIS interface.

  • teledyne
    HiRel Semiconductors Releases Wideband 50 GHz RF Switch

    Teledyne HiRel Semiconductors has announced the release of the TDSW050A2T, a high-performance, rad-tolerant RF switch designed for demanding aerospace and defense applications.

  • pSemi - CMOS switch
    UltraCMOS SP4T RF Switch: PE42447

    The PE42447 is an SP4T RF switch that supports a frequency range from 10 MHz to 8 GHz. It delivers extremely low insertion loss and high linearity with high input power handling.

  • GettyImages-1327977866-cell-culture-sample-laboratory
    Development Solutions For Biologics CHO CLD Platforms

    Aragen offers choice of CLD platforms, efficient Upstream and Downstream process development

  • Cityworks-Screenshot_Water-Online-450x300_42224
    Trimble Cityworks

    Deliver cost-effective, reliable public infrastructure—from permitting and construction to operation, maintenance and replacement. From the office to the field, Trimble Cityworks helps you improve service to your community while increasing safety, efficiency and performance.

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About Nutrient Removal

Nutrient removal from wastewater consists of treating wastewater to remove nitrogen and phosphorus before it reenters natural waterways. High levels of nitrogen and phosphorus in wastewater cause eutrophication, a process where excess nutrients stimulate excessive plant growth such as algal blooms and cyanobacteria. The decomposition of the algae by bacteria uses up the oxygen in the water causing other organisms to die. This creates more organic matter for the bacteria to decompose. In addition, some algal blooms can produce toxins that contaminate drinking water supplies.

As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program regulates point sources, such as municipal wastewater treatment plants, that discharge pollutants as effluent into the waters of the United States. In recent years, many of the States’ environmental bodies have lowered nutrient limits to arrest eutrophication. Maryland’s effort to protect the Chesapeake Bay and its tidal tributaries is perhaps the most notable example of nutrient removal in the US. Nutrient removal continues to be a growing area of focus for wastewater treatment throughout the world.   

The removal of nitrogen and phosphorus require different nutrient removal processes. To remove nitrogen, the nitrogen is oxidized from ammonia to become nitrate through a process called nitrification. This process is then followed by denitrification where the nitrate is reduced to nitrogen gas which is released to the atmosphere and removed from the wastewater.

Nitrification is a two-step aerobic process which typically takes place in aeration tanks. Denitrification requires anoxic conditions to encourage the appropriate biological conditions to form. The activated sludge process is often used to reduce nitrate to nitrogen gas in anoxic or denitrification tanks.

Phosphorus can be removed biologically using polyphosphate accumulating organisms (PAOs) which accumulate large quantities of phosphorus within their cells and separate it from treated water. Phosphorus removal can also be achieved by chemical removal. Once removed as sludge, phosphorus may be stored in a land fill. However, many municipalities and treatment facilities are looking to resell the biosolids for use in fertilizer.