An external micro-interface papermaking wastewater treatment system and a wastewater treatment method are proposed. The wastewater treatment system includes a grating water collection tank, a first coagulation sedimentation tank, an inclined screen and a second coagulation sedimentation tank which are connected in sequence, a heat exchanger, a preheater and a wet oxidation reactor, wherein the heat exchanger is provided with a first inlet, a first outlet, a second inlet and a second outlet. A feed inlet is disposed on a side wall of the wet oxidation reactor, an oxidation water outlet is disposed on a top of the wet oxidation reactor, the feed inlet is connected with a micro-interface generator for dispersing and breaking gas into gas bubbles, a liquid phase inlet and a gas phase inlet are disposed on the micro-interface generator, and the gas phase inlet is connected with an air compressor.

A modular liquid waste treatment system is disclosed. In accordance with some embodiments, the system includes a central distribution unit and one or more treatment fins in flow communication therewith. The distribution unit may be configured to receive liquid waste from a given source and distribute that waste, at least in part, to one or more treatment fins. In turn, bacteria present in a given treatment fin treat the liquid waste, and the resultant treated liquid may drain from the fin to the surrounding environment. In some embodiments, a given treatment fin may include porous media providing a large surface area on which bacteria may grow to facilitate treatment. The system may be installed in and/or above the ground, and in some cases may be surrounded, at least in part, with treatment sand and/or other treatment media. The system may be used in aerobic and/or anaerobic processing of liquid waste.

Sludge, for example primary sludge or waste activated sludge or both from a wastewater treatment plant, is pre-treated prior to anaerobic digestion. The pre-treatment includes an optional mechanical treatment to reduce the viscosity of the sludge and a biological hydrolysis treatment. The biological hydrolysis treatment may be performed in a series of reactors some of which are maintained at a temperature in the range of 50 to 70° C. The reactors provide a combined residence time in the range of 0.5 to 6 days. Optionally, measurements of the pH of the sludge during or after biological hydrolysis, or the production of biogas from a downstream anaerobic digester, may be considered in adjusting the temperature of one or more of the biological hydrolysis reactors.

A method for cleaning a filter membrane in which at least 2 types of cleaning water containing oxidizing agents are prepared, and the filter membrane is cleaned using the cleaning water in an ascending order of the oxidizabilities of the oxidizing agents. Moreover, an apparatus for cleaning a filter membrane of the present invention comprises a means for cleaning the filter membrane using at least 2 types of cleaning water containing oxidizing agents, and the filter membrane is cleaned using the cleaning water in an ascending order of the oxidizabilities of the oxidizing agents. The method and the apparatus for cleaning a filter membrane can efficiently remove polluting substances adhered to a filter membrane while reducing the amounts of oxidizing agents and water to be used, and can maintain the filtration performance for a long period of time.

This disclosure is directed to a mobile recovery system and methods. The system may receive a medium containing particles to be separated. The mobile system may include several modules that may remove various particles or substances from the medium and/or treat the medium to change a characteristic of the medium. The system may be located on a mobile platform. The system may be configure to perform the desired functions and methods either in a temporarily fixed location or while in motion.

A method and apparatus for removing the barium and strontium salts in water that flows back to the well head after hydrofracturing in gas well drilling. Trace levels of iron salts may also be removed from the waste frac water, followed by removal of the calcium and magnesium salts, where applicable. The barium and strontium salts are precipitated in the inert sulfate form, which renders the resulting solids mass suitable for conventional landfill or on-site disposal, and more significantly, for potential reuse and as an additive to certain well drilling processes. The calcium and magnesium salts are similarly inert and suitable for conventional disposal. The process may be managed to selectively remove barium and strontium salts to desired levels, depending upon the intended reuse or disposition. The apparatus may be provided in a highly compact portable configuration that is transportable by a highway vehicle.

The present disclosure relates to a method for separation of solid particles from a waterbody. Preferably, the present disclosure relates to a method, wherein a combination of chemicals including coagulant(s) and flocculant(s) are employed for said separation of solid particles, wherein suitable examples of solid particles are living organisms and non-living matter, wherein living organisms include autotrophs such as phototrophs, which are either microscopic or macroscopic in nature (algae). The disclosure thus particularly relates to method of chemical coagulation and flocculation for separating solid particles, preferably either algae or bacteria or both from a waterbody. The present disclosure also provides for an alternate method, wherein the aforesaid method of coagulation and flocculation is combined with electro-coagulation and/or pH modulation strategies for separation of said solid particles in any sequence.

A method to remove oil from an oily water stream includes the step of pressure controlling a release of dissolved gases from the stream as the stream passes through two or more stages of gas flotation treatment. The operating pressure of the first stage of flotation treatment is purposefully reduced relative to that of an upstream unit so that a certain controlled percent volume of dissolved gases is released. The operating pressure of the second stage of flotation treatment is then purposefully reduced relative to that of the first stage so that another controlled percent volume of dissolved gases is released. Any subsequent flotation treatment stage is at a lower operating pressure than that of the previous stage so that the subsequent treatment stage releases a controlled percent volume of dissolved gases. By controlling the operating pressure in this way, overall separation performance is improved.

Improved reverse osmosis (RO) systems include at least first and second stages wherein each stage has at least one RO membrane, each stage has a feed stream inlet, a permeate stream outlet, and a concentrate stream outlet, the feed stream inlet of the second stage is coupled to the concentrate stream outlet of the first stage, the second pressure is greater than the first pressure, and pressure exchangers associated with each of the first and second stages are configured to recover energy from the second stage concentrate stream. The systems include M reverse osmosis membranes in the first stage and N reverse osmosis membranes in the second stage, wherein M≧N. The first pressure and second pressure are configured so that spatial variance in flux of the first stage permeate stream relative to flux of the second stage permeate stream is minimized.