A reject valve of a reverse osmosis device, which is especially suited for brackish water reverse osmosis devices, which require a low system pressure less than 15bar. The valve keeps the system pressure substantially constant in a pre-defined range of the reject volume. The size of the inflow channel is adjusted by a spring-operated cone, which never entirely closes the channel, which forms a constant throttle until the pressure of the inflow has risen to approximately three quarters of the pressure arranged by the spring and prevailing at maximum volume of the reject flow. This operation is arranged structurally such that onto the shaft of the cone is fixedly supported a transverse plate abutting the inner wall of the body, which as pressed by the compression spring is supported by the end of an element connected to the end of the body, wherein the cone is in its lowest position.

Described herein are water desalination membranes and methods of desalinating water. Sulfonated poly(arylene ether) polymers are also disclosed, including those comprising one or more sulfonate groups at various points along the polymer chain. The polymers may be used as at least a portion of a water desalination membrane. The polymers described herein are useful for preventing transport of aqueous ionic species (e.g., Na.sup.+ and Cl.sup.−) across a membrane made from the polymers while allowing water to pass. Chlorine-stable polymers are described, as well as polymers exhibiting good performance for rejecting monovalent cations in the presence of polyvalent cations.

A system for treating a tetraalkylammonium hydroxide-containing liquid having a high-pressure type reverse osmosis membrane device concentrating a liquid to be treated containing tetraalkylammonium hydroxide at a concentration side, and a line for supplying the concentrated liquid to be treated by the reverse osmosis membrane device to an evaporator further concentrating the concentrated liquid to be treated.

An automatic rainwater collection system, with a high degree of autonomy and sensitivity, which allows the collection and use of rainwater, in open spaces, areas of difficult access and/or lacking of water extraction systems, as well as in domestic spaces such as gardens or roofs, without additional adaptations for its use and which works with solar energy. The automatic rainwater collection system is conformed by: a flower-shaped obturable rainwater receiving element, which comprises: a plurality of internal petals and a plurality of external petals that can be opened or closed in an automated manner, a sensor with high sensitivity to droplet impacts and/or relative humidity, which is operatively connected to a motor to control the opening and closing of the plurality of petals of the rainwater receiving element; a support frame, which functions as a support for the obturable rainwater receiving element and as a water storage media; a modular system for filtering water, connected to said central media of water accumulation, which comprises a plurality of filtering modules, which provide different filtering options depending on the quantity and combination thereof in order to obtain different qualities of water for use in several activities; and a water storage media, which further functions as base and support of the collection system.

Biocide can be controllably added to a feed stream for a membrane. In some examples, the feed stream is separated into a primary feed stream and a secondary feed stream, for example, with the secondary feed stream having a lower flow rate than the primary feed stream. The secondary feed stream may be used to monitor and control the addition of the biocide, which is then diluted when the secondary feed stream is combined with the primary feed stream to form a combined stream for delivery to the membrane.

Water or wastewater filtration processes and systems have a plurality of membrane modules, each having filter media therein, the plurality of membrane modules arranged in parallel fluid flow, a main bottom feed conduit, a main top feed conduit, and separate feed conduits fluidly connecting the main bottom feed conduits and the main top feed conduits to respective membrane modules. A main filtrate conduit, and separate filtrate conduits fluidly connect respective membrane modules to the main filtrate conduit. A backwash conduit fluidly connects the main filtrate conduit to respective membrane modules through the main top and bottom feed conduits. A pump having a pump feed conduit and a pump discharge conduit, the pump discharge conduit fluidly connected to the main top and bottom feed conduits, and a plurality of automatically controllable valves positioned in the main top and bottom feed conduits, the main filtrate conduit, the pump discharge conduit, and the backwash conduit, with a controller configured to actuate the plurality of automatically controllable valves to control feed and backwash flows through the membrane modules using pressure developed only by the pump. The pump is preferably operated by a variable-speed prime mover.

A water treatment system includes: EDI having deionization chamber that deionizes water that contains boron and concentration chambers in which concentrated water flows; and a cooler to cool the water supplied to deionization chamber or the concentrated water supplied to concentration chambers. Alternatively, water treatment system includes EDI having deionization chamber that deionizes water that contains boron, concentration chambers in which concentrated water flows, and electrode chambers in which electrode water flows; a cooler that adjusts temperature of the water or temperature of the concentrated water supplied to concentration chamber; and a controller that controls the cooler such that the cooler adjusts the temperature of the water supplied to deionization chamber or the temperature of the concentrated water supplied to the concentration chambers within a range of 10-23° C., based on the temperature of the water, temperature of treated water of EDI, the temperature of the concentrated water, or temperature of the electrode water.

An apparatus for filtering and mineralizing a fluid. The apparatus includes an amount of contaminated fluid located in a reservoir and a cartridge that is located downstream from the reservoir and in fluid communication with it. A filter is in fluid communication with the reservoir and the cartridge. The contaminated fluid is pumped along a pathway from the reservoir to the cartridge so that the contaminated fluid moves through the filter to generate filtered fluid in the cartridge. A pre-determined amount of an additive is associated with the cartridge for adding to the filtered fluid to generate a final fluid with the amount of the additive material.

A water treatment system comprises a source of water including one or more contaminants, an electrocoagulation cell including a housing defining a fluid flow conduit, an anode disposed within the fluid flow conduit, and a cathode disposed within the fluid flow conduit, the housing including an inlet fluidly connectable to the source of water and an outlet, a solids/liquid separation system having an inlet fluidly connectable to the outlet of the housing of the electrocoagulation cell, a solids-rich outlet, and a solids-lean outlet, and a ballast feed system configured to deliver a ballast to the solids/liquid separation system.

A filter assembly comprises an outer casing, filters and a pipe member connected to first, second and third filters and comprising an inlet flow path and an outlet flow path. The inlet flow path comprises a first inlet flow path connected to the first filter, a second inlet flow path connected to the second filter, a third inlet flow path connected to the third filter, and an inflow member comprising a branch point to allow water to flow in parallel through the first inlet flow path and the second inlet flow path. The outlet flow path comprises a first outlet flow path for water to be discharged from the first filter, and a second outlet flow path for water to be discharged from the second filter. Water discharged from the first outlet flow path from the second outlet flow path is guided and introduced into the third inlet flow path.