US Patent:
20140083936, Mar 27, 2014
Inventors:
- Washington DC, US
Eugenio Giraldo - Robbinsville NJ, US
Norman D. Dockett - Silver Spring MD, US
Haydee De Clippeleir - Hamme, BE
Bernhard Wett - Innsbruck, AT
Assignee:
D.C. Water & Sewer Authority - Washington DC
International Classification:
C02F 3/12
C02F 3/30
US Classification:
210605, 210194, 210623, 210173, 210174, 210 961, 210601, 210138, 2101953, 210624, 210625, 210626
Abstract:
An apparatus and method for selecting, retaining or bioaugmenting solids in an activated sludge process for improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size, compressibility or shear resistance. The screens are used to separate and select slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process. A swapping screen arrangement provides another means of selecting various particles. The exposed shear rate or time, particle compression, or SRTs can be adjusted manually and/or automatically in response to detected readings from an instrument such as a spectrophotometer or other optical approaches to optimize selection of organisms. The present disclosure may be configured as an activated sludge system operated at different solids residence times (SRT) for different solids fractions allowing slow growing organisms to get established in competition with faster growing organisms or aggregates thereof.
