Methods and systems for removing pollutants from water include one or more filter systems and a hybrid wetland system. Hybrid wetland systems may include a first pipe transporting water from a body of water to a settling tank, a first constructed wetland connected to the settling tank via a second pipe, and a first filter system removing pollutants from water passing through the second pipe. A second filter system is positioned within the first wetland to further remove pollutants. The system also includes a second constructed wetland connected to the first constructed wetland via a third pipe and a water control chamber. Filtered water exiting the first constructed wetland flows through the water control chamber, through the third pipe, and into the second constructed wetland. A fourth pipe extends between the second constructed wetland and the body of water, returning filtered water to the body of water.

The present invention provides advanced livestock wastewater treatment systems, devices and methods for simultaneous removal of nitrate (nitrite) from treated wastewater at cathode chamber and of organics, suspended solids and malodor (caused by volatile fatty acids) from raw wastewater at anode chamber using anaerobic bioelectrochemical system (BES). The present invention provides a device comprising at least one anode chamber equipped inside with at least one anode, and at least one cathode chamber equipped inside with at least one cathode, wherein the anode chamber is attached to the cathode chamber via separator in order to transport anions or cations between the anode chamber and the cathode chamber.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

The present invention relates in part to a filter comprising a tubular housing having a proximal end, a distal end and a housing lumen therethrough; a tubular membrane having a proximal end, a distal end and a membrane lumen therethrough, wherein the tubular membrane is positioned within the housing lumen; a contaminated fluid sample inlet fluidly connected to the proximal end of the membrane, and a contaminated fluid sample outlet fluidly connected to the distal end of the membrane, thereby creating a sample flow-path from the sample inlet through the membrane lumen to the sample outlet; and a purification material inlet fluidly connected to a distal region of the housing lumen, and a purification material outlet fluidly connected to a proximal region of the housing lumen, thereby creating a purification material flow-path from the purification material inlet through the housing lumen to the purification material outlet; wherein the direction of the sample flow-path is in the opposite direction of the purification material flow-path. The invention also relates a method of purifying a contaminated fluid using said filter.

Disclosed is a rotating cored-type biological treatment device for wastewater with low carbon content and use thereof. The device includes a composite frame (1), several biological packing columns (2), a rotating tray (3), a rotating shaft, and a base (4), wherein the biological packing columns (2) are detachably mounted inside the composite frame (1); the rotating shaft is vertically arranged on the base (4) and can rotate; the rotating tray (3) is fixedly sheathed on the rotating shaft, and the composite frame (1) is disposed on the rotating tray (3); and the rotating tray rotates with the rotating shaft, which driving the composite frame (1) and the biological packing columns (2) therein to rotate. The rotating cored-type biological treatment device has the advantages of high efficiency and being renewable and environment-friendly, etc.

The invention relates to a method for nitrogen removal from aqueous medium, comprising steps of (a) converting NH.sub.4.sup.+ in the aqueous medium to NO.sub.2.sup.− by partial aerobic nitrification, (b) partially reducing the obtained NO.sub.2.sup.− to N.sub.2O in anoxic conditions, and (c) decomposing N.sub.2O to N.sub.2 with energy recovery. A mixture of ferrous sulfate and ferric sulfate is used in step (b) for reduction of NO.sub.2.sup.− to N.sub.2O.

A nitrate reduction method includes the step of reducing at least one type selected from a group of nitrates and nitrites at an active site included in a defect of graphene in a reduction reaction, wherein the graphene is a reduced product of graphene oxide, and the defect of the graphene is derived from a defect of the graphene oxide.

An organic wastewater treatment method based on a multi-element co-doping TiO.sub.2 nano photocatalytic material includes preparing a sulfur-titanium dioxide mixture, hydrothermally reacting the sulfur-titanium dioxide mixture with copper chloride, ammonia, strong alkali, a transition metal salt and the like, reacting the resulting reaction product with hydrofluoric acid, then performing temperature programming thermal treatment in air to obtain the multi-element co-doping TiO.sub.2 nano photocatalytic material, and then treating organic wastewater with the multi-element co-doping TiO.sub.2 nano photocatalytic material under the irradiation of visible light. The organic wastewater treatment method is efficient and rapid, safe and environmental-friendly, can thoroughly degrade many types of organic pollutants, ammonia nitrogen and the like, and does not cause secondary pollution; furthermore, the adopted multi-element co-doping TiO.sub.2 nano photocatalytic material can be regenerated and recycled only by simple calcination, and the cost is inexpensive.

A method of cultivating aquatic product and plant contains steps of: (A) Preparing a cultivation tank with cultivation water; (B) Aerating the cultivation water; (C) Drawing overflow water in a top of the cultivation tank and foul water in a bottom of the cultivation tank into a protein separator and a first ultrafiltration unit; (D) Collecting bubbled fluid from the protein separator and concentrated waste fluid from the first ultrafiltration unit into a collection chamber; (E) Pumping the cultivation wastewater into a second ultrafiltration unit and filtering the cultivation wastewater by using ultrafiltration films of the second ultrafiltration unit; (F) Discharging cloudy high-protein concentration fluid into a first gathering bucket; (G) Pumping filtered fluid filtered by the plurality of ultrafiltration films of the second ultrafiltration unit into a Nano-filtration unit; and (H) Flowing the recyclable water into the cultivation tank from the recycle tank.

A system and method for treating wastewater includes two or more biological reaction zones separated by chamber walls. The system and method for treating wastewater includes static recycle of a mixed liquor from a second biological reaction zone to a first biological reaction zone.