The present invention relates to a filtering device for a water treatment system comprising a biological treatment device adapted to provide a sludge from wastewater or filtrated wastewater, and/or the biological treatment device being fluidic connectable to or in fluidic connection with the filtering device for receiving filtrated wastewater from the filtering device and for delivering sludge to the filtering device. The filtering device is a cake filtration device comprising a fluid penetrable support structure and the support structure is provided as one or more tubular elements having a filtration cake provided on the inside of the fluid penetrable support structure. The filtering has device an inlet being connectable to receive liquid to be filtered so that the flux of liquid to be filtered is from the inside of the support structure, through the filtration cake and to the outside of the support structure thereby providing a filtrate, an outlet for outletting liquid from the interior of the tubular element, and a filtrate outlet for outletting filtrate from the filtering device. The filtration cake is being provided by deposition of solids from the sludge formed in the biological treatment device.

Described is a method of treating wastewater. The method includes receiving the wastewater at a ballasted activated sludge secondary treatment aeration basin. The method also includes adding a ballast material to the wastewater, treating the wastewater in the ballasted activated sludge secondary treatment aeration basin to produce a ballasted mixed liquor effluent, receiving the ballasted mixed liquor effluent at a high-rate heavy solids removal zone that includes one or more high-rate heavy solids removal units, and removing ballasted heavy solids from the ballasted mixed liquor effluent using the one or more high-rate heavy solids removal units to produce a concentrated ballasted heavy solids effluent and a clarified liquid effluent. Also described is a system for treating wastewater including a ballasted activated sludge secondary treatment aeration basin and a high-rate heavy solids removal zone for treating a ballasted mixed liquor effluent.

Provided is a process comprising receiving overflow of wastewater influent from a clarifier basin in a clarifier effluent collection trough; receiving inflow of wastewater influent from the clarifier effluent collection trough in a filter influent flow inlet distribution channel; maintaining substantially constant liquid level in the filter influent inlet distribution channel; applying hydrostatic pressure to push wastewater influent from the filter influent flow inlet distribution channel into an upflow backwash filter contusing denitrifying biomass or deammonification biomass; backwashing the backwash filter with a gas lift backwash flow; returning filter reject backwash wastewater from rejection compartment of the filter through denitrifying bacteria or deammonification biomass recycle return line to a location upstream of the filter; and recycling denitrifying bacteria or deammonification biomass from denitrifying bacteria or deammonification biomass recycle return line to at least one of the clarifier effluent collection trough, filter influent flocculation tank, or filter influent flow distribution channel.

A wastewater treatment system including an aeration unit, a contact tank, a dissolved air flotation unit, and a biological treatment unit is disclosed. A method of retrofitting a wastewater treatment system by providing an aeration unit and fluidly connecting the aeration unit to the wastewater treatment system is also disclosed. A method of treating wastewater including aerating wastewater with oxygen, combining the aerated wastewater with activated sludge, floating biosolids from the activated wastewater, and biologically treating the effluent is also disclosed. The method optionally includes combining the floated biosolids with the aerated wastewater and/or activated wastewater. A method of facilitating treatment of high solids content wastewater is also disclosed.

A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. A series of biological process zones lead to a secondary clarifier. Mixed liquor sludge, preferably from an aerobic zone, goes through a classifier or separator processing flow from the aerobic zone, to the secondary clarifier. In a sidestream process that can be included a portion of sludge preferably from an aerobic zone goes through a classifier or separator to selectively produce a granular-rich effluent, and the clarifier may also have a separator to further concentrate granular biomass, most of which is cycled back to an initial multi-stage anaerobic process zone. The anaerobic zone is structured and operated to encourage growth of granules in subsequent process zones.

An organic wastewater treatment device includes a biological treatment tank in which biological treatment units are connected in series along a flow of organic wastewater. Each biological treatment unit has a pair of an anoxic tank disposed on an upstream side, and an aerobic tank disposed on a downstream side in which a membrane separation device is immersed in activated sludge. The activated sludge returns from a most downstream-side aerobic tank to a most upstream-side anoxic tank through a sludge return path. Whether to stop an operating membrane separation device and whether to start a stopped membrane separation device are determined for each biological treatment unit based on at least one of an inflow amount of the organic wastewater, a tank water level, a transmembrane pressure difference of each membrane separation device, a T-N concentration of the treated water, and an NH3-N concentration of the treated water as an index.

A method for treating a sludge derived from sewage or wastewater, the method comprising subjecting the sludge to a treatment step at a pH of 8.9 or greater and a free ammonia (FA) content of 100 mg NH.sub.3N/L or greater. The treated sludge may be fed to a bioreactor to produce methane.

A process for the treatment of wastewater is disclosed, which comprises (a) contacting the wastewater with fast settling sludge from step (c) in an anaerobic zone, obtaining a mixture of wastewater and sludge; (b) subjecting the mixture from step (a) and slow settling sludge from step (c) to an aerobic zone, obtaining a water and sludge mixture; (c) subjecting a first part of the mixture from step (b) to a sludge selection step, wherein sludge is selected based on settling velocity and a first portion containing slow settling sludge and a second portion containing fast settling sludge are collected, wherein average settling velocity of the fast settling sludge is greater than that of the slow settling sludge, and wherein the first portion is returned to step (b) and the second portion is returned to step (a); and (d) separating sludge from a second part of the mixture from step (b).

A wastewater treatment process elicits microorganisms to convert a waste stream/organic resource to intracellular biopolymer polyhydroxyalkanoate (PHA). The process includes (i) waste stream/organic resource composition feed criteria, (ii) configuration coupled with operational parameters, and (iii) PHA-laden biomass separation and stabilization. A waste stream/organic resource capable of producing enhanced levels of PHA may be selected based on a combination of criteria, which may include short chain fatty acid concentration, protein concentration, polysaccharides concentration, and total suspended solids concentration. The waste stream is introduced into an aeration basin or sequencing batch reactor upon a specific configuration and operated under various parameter combinations for selecting/enriching microorganisms capable of producing PHA. The PHA-laden biomass is separated and stabilized for downstream PHA related product beneficial uses. The present process achieves concurrent wastewater treatment and PHA production, where PHA level (of more than 10% on a cell-weight basis) otherwise could not be obtained.

A wastewater treatment system includes a first sub-system having a biological treatment unit and a second sub-system having a dissolved air flotation unit. A method of treating wastewater includes directing a first stream of wastewater to a biological treatment unit and directing an overflow stream of wastewater to a dissolved air flotation unit. A method of facilitating treatment of overflow wastewater in a biological treatment system includes connecting an overflow treatment system in a parallel configuration with the biological treatment system, the overflow treatment system having a dissolved air flotation unit, and directing a fraction of activated sludge from the biological treatment system to the overflow treatment system.