Disclosed are devices, systems and methods for operation and control of gravity-fed fluid flows in water and wastewater related systems. The disclosed flow control system uses gravity to provide a flow of a fluid from a fluid source and a motorized flow control device fluidically coupled to the fluid source to control a defined flow rate of the flow by changing a position of an internal volume of the flow control device through which the fluid flows relative to a fixed level of the fluid in the fluid source. The disclosed devices, systems and methods can be used in a wide variety of systems for environmental and low-energy demand applications such as, for example, a wastewater treatment system to control a flow of wastewater in the system.

The present application provides a method for treating and recycling organic wastewater, comprising: 1) pretreating the organic wastewater; 2) subjecting an effluent obtained after pretreatment in step 1 to a heterogeneous Fenton reaction with Hangjin clay-supported nano-Fe.sub.3O.sub.4 as a catalyst, separating the catalyst from a reaction solution after completion of the reaction, and subjecting the reaction solution to a reaction to remove COD; 3) subjecting an effluent obtained in step 2 to an anaerobic ammonia oxidation reaction to denitrify by ammonia nitrogen reacting with nitrite nitrogen; 4) subjecting an effluent obtained in step 3 to an aerobic microbial decomposition and ultrafiltration membrane separation to remove COD and ammonia nitrogen; 5) filtering an effluent obtained in step 4 to remove large particles; 6) supplying an effluent obtained in step 5 to an RO system, and using an effluent from the RO system as circulating cooling water, and subjecting concentrated water from the RO system to a softening treatment; and 7) supplying softened concentrated water obtained in step 6 to an NF system for treatment, evaporating an effluent obtained after the treatment to recover NaCl, and returning a resulting concentrated water to step 1. The present application also provides a device for implementing the method for treating and recycling an organic wastewater.

The present invention provides an ecological method for denitrification and phosphorus removal in wastewater treatment process, which relates to the field of sewage treatment technology, The present invention provides a nitrogen and phosphorus removal system, comprising a nitrogen and phosphorus removal unit and a sulfate adsorption unit. The nitrogen and phosphorus removal unit is packed with coarse sand layer, deoxidizing layer and sulfur/iron mixture layer, while the sulfate adsorption unit is filled with modified hydrotalcite. Both of the units are filled with solid material, which effectively avoid the contamination that causes by liquid carbon source feeding. The application of the present invention can realize a completely denitrification, which achieve a maximum removal rate of 100%, a phosphorus removal efficiency of about 80%. The TP concentration is below 0.5 mg/L in the treated effluent, while the average sulfate removal rate is about 50%.

A process for treating waste waters with TDS?20 g/l, possibly containing organic substances, includes the following steps: a. separating the saline wastewater or waste waters from suspended solids and heavy pollutants by physical separation, forming a saline stream free of suspended solids and heavy pollutants; b. subjecting the saline stream to reverse electro-dialysis, using a reservoir solution to reduce the saline concentration and forming a diluate and a diluted stream (waste water) with TDS not higher than 20 g/l; and c. biologically treating the diluted stream obtained in (b) forming biological sludge, or excess sludge, and clarified water.

A bacterial fuel cell including a plurality of anodes and a plurality of cathodes in liquid communication with a liquid to be purified, the plurality of anodes and the plurality of cathodes each including a metal electrical conductor arranged to be electrically coupled across a load in an electrical circuit and an electrically conductive coating at least between the metal electrical conductor and the liquid to be purified, the electrically conductive coating being operative to mutually seal the liquid and the electrical conductor from each other.

The present application provides a device for treating a black and odorous water body comprising a pre-treatment unit, a biomimetic intestine tubular purification system which imitates a digestion of small intestine, a microbial fuel cell which imitates a digestion of large intestine, and an inclined tube sedimentation tank which imitates human excretion.

A method and apparatus for reducing brine effluent from desalination plants by modifying microbial electrochemical cells are disclosed. To reduce brine generation, the contaminant salts from saline water, such as seawater or wastewater, which are to be desalinated, are accumulated in two organic solvent solutions. The generated organic solvent solutions are then mixed in a container wherein the acids and alkalis combine to produce salts which precipitate out of the organic solvent solution due to low solubility. The method may employ bipolar membranes or cation exchange membranes and anion exchanges membranes. Some embodiments of this invention can be used to desalinate brine from any available source and reduce the operational cost of brine treatment.

The present application provides a method for treating a black and odorous water body comprising the following steps: pre-treating the black and odorous water body; passing the pre-treated water body through a biomimetic intestine tubular purification system which imitates a digestion of small intestine; passing the tubular purification system-treated water body into a microbial fuel cell which imitates a digestion of large intestine to treat the water body; and pumping the microbial fuel cell-treated water body into an upward flow inclined tube sedimentation tank to treat the water body.

Provided is a microbial fuel cell including a cathode and an anode, wherein the cathode includes a waterproof gas diffusion layer including a siloxane and a catalyst layer including a binder, wherein a surface of the gas diffusion layer opposite the catalyst layer contacts air, and the anode includes electrogenic bacteria. Also provided is a method for making a microbial fuel cell, including fabricating a cathode, wherein fabricating includes disposing a siloxane solution onto a surface of a substrate, wherein the siloxane solution includes a siloxane and a solvent, drying the siloxane solution to form a waterproof gas diffusion layer, and placing the gas diffusion layer on a catalyst layer including a binder, and facing an anode with the cathode whereby the gas diffusion layer faces away from the anode and contacts air.

The present disclosure belongs to the technical field of wastewater treatment, and discloses an electrochemical nitrogen and phosphorus removal device and a method. The device includes a three-dimensional electro-catalytic oxidation unit reactor, a three-dimensional electro-biological coupling unit reactor, a light filter material filter unit reactor and a three-dimensional electro-flocculation phosphorus removal unit reactor; a main water inlet pipe, the three-dimensional electro-catalytic oxidation unit reactor, the three-dimensional electro-biological coupling unit reactor and the light filter material filter unit reactor are sequentially connected; a water outlet pipe of the light filter material filter unit reactor is connected to both a main water outlet pipe and a water inlet pipe of the three-dimensional electro-flocculation phosphorus removal unit reactor; and a water outlet pipe of the three-dimensional electro-flocculation phosphorus removal unit reactor is connected to a water inlet pipe of the light filter material filter unit reactor through a reflux pump and a check valve. An aeration pipe and a blow-down pipe are provided at bottoms of tanks of the reactors, respectively. The present disclosure can achieve the purpose of efficient sewage treatment by means of the combined action of electrochemical flocculation, electro-catalytic oxidation and electro-active microorganisms. The device and the method have the advantages of high nitrogen and phosphorus removal efficiency and the like.