A system and method for algal harvesting and destabilization are provided. The system includes a multifunctional reactive electrochemical membrane (REM). The application of an electrical current generates reactive species at the REM surface and oxidizes algae and soluble organic compounds. This novel type of membrane filtration avoids the use of harmful chemical additives. In addition, it provides the benefits of avoiding polymer aging, membrane fouling, and high costs caused by high transmembrane pressures and frequent membrane cleaning. Traditional membrane separation that significantly suffers from membrane fouling due to either the formation of a cake layer of algal cells, or more commonly due to organic matter adsorption onto the membrane surface is significantly avoided.

The present invention relates to a water treatment method including: a filtration step of feeding water to be treated to a membrane filtration device having loaded therein a porous separation membrane and performing filtration treatment to obtain filtrate; a discharging step of discharging the water to be treated in the membrane filtration device, which has been separated and concentrated by the porous separation membrane; and a cleaning step of cleaning the porous separation membrane by at least one treatment of physical cleaning and chemical cleaning, in which a cycle including a combination of the filtration step, the discharging step and the cleaning step is repeated multiple times, thereby obtaining filtrate. In each cycle, the filtration step and the discharging step are repeated multiple times, and the cleaning step is then carried out.

Provided are reverse-osmosis-membrane device capable of treating raw water including a large amount of membrane foulants, such as MBR-treated water, with stability while preventing a reduction in the amount of permeate, and a method for operating the reverse-osmosis-membrane device. The raw water includes a high-molecular organic substance having a molecular weight of 10,000 or more at a concentration of 0.01 ppm or more. The reverse-osmosis-membrane device includes a reverse-osmosis-membrane element including a membrane unit, the membrane unit including a reverse osmosis membrane having a thickness of 0.1 mm or less, a feed spacer disposed on a surface of the reverse osmosis membrane, and a permeate spacer disposed on the other surface of the reverse osmosis membrane. The reverse-osmosis-membrane device is operated at a permeation flux of 0.6 m/d or less.

Integrated methanogenic anaerobic reactor and membrane bioreactor, and method for eliminating organic matter and nitrogen in urban or industrial wastewater, preferably with COD concentrations between 150 and 5000 mg/L and where the eliminations of total nitrogen that occur are between 15 and 50 mg/L, at temperatures above 15° C. The wastewater treatment takes place thanks to three stages of treatment: methanogenic anaerobic stage, anoxic stage with biofilms and suspended biomass and aerobic filtration stage with biofilms and suspended biomass.

A potting system comprising a potting unit having an integrated compressible seal formed from the same material that the potting unit is composed of.

A method for operating a membrane separation device includes (a) setting a flow amount M(t) of permeated water and extracting the permeated water from the membrane separation device by the set flow amount M(t), and (b) temporarily stopping the extracting the permeated water, when a water level of a first water tank in which the membrane separation device is immersed, a water level of a second water tank in communication with the first tank, or a water level of a third water tank receiving overflowing water from the first water tank becomes lower than a predetermined halt water level. M(t), which is the flow amount of the permeated water during a time period t, satisfies a equation M(t)=KQ(t−1), where K is a gain (K>1), and Q(t−1) is an amount of inflow of the water-to-be-treated during a time period t−1 immediately prior to the time period t.

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.

A separation-membrane module 1 includes an element block 2 that is formed by arranging, in parallel, a plurality of separation-membrane elements 4 that are formed by arranging a pair of separation-membranes with their respective permeate surfaces in opposition to each other and sealing the edges of the pair of the membranes; and an aeration block 3 that includes an aeration pipe 31 and that is disposed under the element block 2. In the element block 2, at least one upper spacer 8 is disposed in the upper portion of each space between the adjacent separation-membrane elements 4, and a lower spacer 9 is disposed under the upper spacer 8 in each space between the adjacent separation-membrane elements 4. And the leftmost and the rightmost separation-membrane elements 4 of the plurality of the separation-membrane elements 4 are secured to a frame 12 at the lower spacers 9.

There are provided processes for treating wastewater. The processes can comprise treating a mixture comprising the wastewater and an activated sludge, in a single reactor, with an electric current having a density of less than about 55 A/m.sup.2, by means of at least one anode and at least one cathode that define therebetween an electrical zone for treating the mixture; exposing the mixture to an intermittent ON/OFF electrical exposure mode to the electric current in which an OFF period of time is about 1 to about 10 times longer than an ON period of time; and maintaining an adequate oxidation-reduction potential in the single reactor. Such processes allow for substantial removal of carbon, nitrogen and phosphorus from the wastewater in the single reactor of various forms and for obtaining another mixture comprising a treated wastewater and solids.

Systems and methods for treating multi-component waste streams. In general, systems and methods described herein employ a first chamber and a second chamber separated by a barrier and a filtration component that is fluidically connected to the first and second chambers. A waste stream to be treated will flow into the first chamber for treatment of the carbon-containing waste, then into the filtration component for the separation of the stream into a solid waste fraction and a liquid waste fraction.