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.

Disclosed are methods of treating wastewater using a membrane bioreactor and achieving a target phosphorus concentration for the membrane permeate stream. These methods include the steps of dosing a wastewater stream with a rare earth clarifying agent and passing the dosed wastewater stream through the membrane to obtain a membrane permeate stream with a permeate concentration that is less than the phosphorus concentration of the influent stream. This permeate concentration also can be equal to or less than a target phosphorus concentration. In the methods as disclosed herein, the rare earth clarifying agent can be chloride salts of one or more rare earth elements and in certain embodiments, the rare earth clarifying agent can be CeCl.sub.3 and LaCl.sub.3.

A sewage treatment apparatus comprises an external box body internally being provided with an anaerobic zone, an aerobic zone, a settling zone, a sewage reduction zone and an apparatus zone separated from each other, wherein the anaerobic zone, the aerobic zone, the settling zone and the sewage reduction zone communicate in sequence, the anaerobic zone communicates with a septic tank, the aerobic zone communicates with the anaerobic zone to reflux a part of mixed liquid to the anaerobic zone, the settling zone communicates with the anaerobic zone to reflux a part of active sludge to the anaerobic zone, and the sludge reduction zone communicates with the anaerobic zone or the septic tank; and the apparatus zone is internally provided with a detection unit for detecting various parameters during a sewage treatment process and a controller for controlling working states according to a detection result of the detection unit.

A method for treating wastewater by using a coagulant that aggregates a phosphorus-containing substance. The method includes executing a reaction phase having a biological treatment phase and a subsequent chemical treatment phase. The chemical treatment phase includes the first substep of mixing the wastewater while injecting a predetermined dose of the coagulant into the basin in order for the coagulant to contact and coagulate the phosphorus-containing substances. The injection of the dose of the binding compound into the basin is performed during a time period equal to or more than a time period required to accomplish two mixing turnovers of the wastewater and equal to or less than a time period required to accomplish seven mixing turnovers of the wastewater. The second substep includes mixing the wastewater in order to flocculate the coagulated substance.

A method for managing a wastewater treatment process. The method includes at least the steps of measuring an amount of at least one nitrogen-containing substance in the influent wastewater (CN, influent), and determining an amount of phosphorous to be removed from the influent wastewater (CP, influent) based on the measured amount of at least one nitrogen-containing substance in the influent wastewater (CN, influent).

An economical method for recovering phosphate or phosphate and nitrogen from liquid streams. A liquid containing phosphate is introduced into a culture of autotrophic microorganisms in the presence of natural or artificial light, thereby producing a liquid effluent with elevated pH and reduced alkalinity. The alkalinity is reduced through the consumption of bicarbonate/carbonate by the autotrophic microorganisms. The effluent is then chemically treated with low-cost chemicals to provide Ca.sup.++ or Mg.sup.++ ions necessary to form a phosphate precipitate such as calcium phosphate or magnesium-ammonium-phosphate (MAP). The autotrophic microorganisms can be cultivated in ponds, lagoons, or photobioreactors. The pH of the culture is adjustable within a preferred range of 7.5 to 10.5 by adjusting the photobioreactor operation. The process includes an economical flotation separator for solid, liquid, gas separation and a means of concentrating ammonia nitrogen that may also be removed during the process of phosphate reclamation.

Disclosed is a facility for treating waste water of municipal or industrial origin, in particular a facility for primary treatment of the water, including a biological contact tank equipped with biological rotating discs, which is connected upstream of a ballasted-floc physiochemical decanter, the decanter being at least made up of a coagulation zone, a flocculation zone, a lamellar decanting zone and a thickening zone and an external circuit allowing the recirculation of the sludge thickened in the thickening zone to the flocculation zone and the biological contact tank.

A method for removal and recovery of phosphorus includes a precipitation step for precipitating phosphorus from a liquid stream comprising at most 30 mg of phosphorus per litre and at most than 50 mg of suspended solids per litre, using a precipitation agent, to form a precipitate, to form a precipitate; a first separation step for separating the precipitate from the liquid stream; a dissolution step for dissolving the precipitate in phosphoric acid to obtain a first solution; and a second separation step for separating the phosphoric acid and the precipitation agent.

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.

A method for removing biologically recalcitrant soluble organic compounds from wastewater simultaneously in an activated sludge process comprising an aeration tank and a solid-liquid separation unit, in which method at least one Al and/or Fe based inorganic metal coagulant is added to the wastewater in the activated sludge process and/or prior to conveying wastewater to an activated sludge process.