Upflow continuous backwash filter
OwnerJohn H. Reid, Wade Tannerinventors
Life of this patent
Estimating the term…
Abstract
An upflow continuous backwash deep bed sand filter (UCBF) having a recycle line for returning carbonaceous denitrifying bacteria attached to biomass to the influent of the UCBF. The recycle line returns the biomass to the treatment process at a location upstream of the upflow continuous backwash filter. Further, a liquid level control unit is provided that reduces fluctuations and significant drop in the liquid level upstream of the upflow continuous backwash filter, thereby avoiding or minimizing flow turbulences, air induction, and undesirable wastewater aeration resulting in the need to dose excessive carbon source to remove dissolved oxygen in the aerated wastewater.
Claims21
An upflow continuous backwash filter system, comprising:
- a clarifier basin;
- a clarifier effluent collection trough being disposed to receive an overflow of wastewater from the clarifier basin;
- optionally, a filter influent flocculation tank;
- an upflow continuous backwash filter being disposed to receive the wastewater influent from the clarifier effluent collection trough or the filter influent flocculation tank through an upflow continuous backwash filter influent distribution channel and filter influent pipeline;
- and,
- a denitrifying bacteria recycle return tank being disposed to receive a return flow from a rejection compartment of the upflow continuous backwash filter, and, optionally, to receive an influent from a mixed liquor inflow line or a return activated sludge (RAS) inflow line.
A method of operating one or more upflow continuous backwash filters, comprising:
- receiving an overflow of a wastewater influent from a clarifier basin in a clarifier effluent collection trough;
- optionally, receiving an outflow of the wastewater influent from the clarifier effluent collection trough in a filter influent flocculation tank;
- receiving an inflow of the wastewater influent from the clarifier effluent collection trough or the filter influent flocculation tank in a main filter influent flow inlet distribution channel;
- applying hydrostatic pressure to push the wastewater influent from the main filter influent flow inlet distribution channel into the one or more upflow continuous backwash filters;
- returning filter reject backwash wastewater from a rejection compartment of the one or more upflow continuous backwash filters through a denitrifying bacteria recycle return line to a location upstream of the upflow continuous backwash filter;
- and,
- optionally, returning biomass from at least one of a mixed liquor flow line and a return activated sludge (RAS) flow line to the location upstream of the upflow continuous backwash filter.
An upflow continuous backwash filter system, comprising:
- a clarifier basin;
- a clarifier effluent collection trough being disposed to receive an overflow of wastewater from the clarifier basin;
- optionally, a filter influent flocculation tank being disposed to receive an outflow of wastewater from the clarifier effluent collection trough;
- a liquid level control unit having a wastewater storage reservoir and at least one automatic filter influent positioning valve, the liquid level control unit being disposed to receive the wastewater influent from the clarifier effluent collection trough or the filter influent flocculation tank;
- and,
- a main filter influent distribution pipeline or channel being disposed to receive the wastewater influent from the liquid level control unit.
A method of operating an upflow continuous backwash filter, comprising:
- receiving an overflow of a wastewater influent from a clarifier effluent collection trough or from a filter influent flocculation tank;
- receiving an outflow of the wastewater influent into a filter influent distribution channel of a liquid level control unit having at least one automatic filter influent positioning valve;
- and,
- maintaining a liquid level of the wastewater influent in the clarifier effluent collection trough or the filter influent flocculation tank or the filter influent distribution channel within a predetermined range.
Dependencies are inferred from the claim text.