Various embodiments may include systems, methods, and devices in which acid produced by a reactor, such as an electrochemical reactor or other type acid producing reactor, is used to produce carbon dioxide (CO.sub.2) from a carbonate and the produced CO.sub.2 is used, or made available for use, for one or more purposes. In some embodiments, the electrochemical reactor may be powered by a renewable energy source.

Various embodiments include cementitious compositions with low levels of embodied greenhouse gas emissions, in particular carbon dioxide, as a result of its production and/or use compared to conventional cementitious materials, such as portland cement. Various embodiments include any cementitious material or materials with low embodied carbon, as well as any material produced using this cement.

A method for stepwise extraction of silica and hydroxide from silicate substances. The silicate substances are leached by chlorine-containing inorganic acids, and the hydroxides are extracted step by step from the leaching liquor by electrochemical deposition method; The raw material of the powder is put in the reactor, inorganic acids, water-soluble alcohol and water are added as the leaching liquor, heated and reacted under the condition of 0.1 MPa or more, and the acidic multi-ion mixed solution and filter residue are obtained by filtration. The acidic multi-ion mixed solution is heated and boiled, and the silicon-containing volatile components are collected, decomposed and deposited in the collector; The deposited volatile components is dried to obtain high purity silica powder; The filter residue is washed and dried to obtain silica; The hydroxides are extracted from the acidic multi-ion mixed solution by electrochemical deposition method.

A method for stepwise extraction of silica and hydroxide from silicate substances. The silicate substances are leached by chlorine-containing inorganic acids, and the hydroxides are extracted step by step from the leaching liquor by electrochemical deposition method; The raw material of the powder is put in the reactor, inorganic acids, water-soluble alcohol and water are added as the leaching liquor, heated and reacted under the condition of 0.1 MPa or more, and the acidic multi-ion mixed solution and filter residue are obtained by filtration. The acidic multi-ion mixed solution is heated and boiled, and the silicon-containing volatile components are collected, decomposed and deposited in the collector; The deposited volatile components is dried to obtain high purity silica powder; The filter residue is washed and dried to obtain silica; The hydroxides are extracted from the acidic multi-ion mixed solution by electrochemical deposition method.

Various embodiments relate to an electrochemical cell for removal of materials from water and methods of using the same. A method of removing phosphorus from water includes immersing an electrochemical cell in water including phosphorus to form treated water including a salt that includes the phosphorus. The electrochemical cell includes an anode including Mg, Al, Fe, Zn, or a combination thereof, a cathode including Cu, Ni, Fe, or a combination thereof. The method includes separating the salt including the phosphorus from the treated water, to form separated water having a lower phosphorus concentration than the water including phosphorus.

Various embodiments relate to an electrochemical cell for removal of materials from water and methods of using the same. A method of removing phosphorus from water includes immersing an electrochemical cell in water including phosphorus to form treated water including a salt that includes the phosphorus. The electrochemical cell includes an anode including Mg, Al, Fe, Zn, or a combination thereof, a cathode including Cu, Ni, Fe, or a combination thereof. The method includes separating the salt including the phosphorus from the treated water, to form separated water having a lower phosphorus concentration than the water including phosphorus.

The chamber frame element of the present invention, which has a smaller amount of voltage drop, consumes less reactive power than the prior art, and exhibits no metal corrosion, is a chamber frame element (14) for an electrolyzer or an electrodialysis cell. The chamber frame element (14) includes: a bag body (141); a frame (142) housed in an interior space of the bag body (141); and an inlet (143) and an outlet (144) to which piping can be attached, which are formed on the outer side of a region where the frame is housed in the bag body (141).

Various embodiments relate to methods and systems for removing phosphorus and/or nitrogen from water. A method of removing phosphorus and nitrogen from water includes passing starting material water including nitrogen and phosphorus through an elevated pH phosphorus removal stage. The method includes passing the water through an electrolytic nitrogen removal stage. The method includes passing the water through a galvanic phosphorus removal stage. The water produced by the method has a lower phosphorus concentration and a lower nitrogen concentration than the starting material water.

Various embodiments relate to methods and systems for removing phosphorus and/or nitrogen from water. A method of removing phosphorus and nitrogen from water includes passing starting material water including nitrogen and phosphorus through an elevated pH phosphorus removal stage. The method includes passing the water through an electrolytic nitrogen removal stage. The method includes passing the water through a galvanic phosphorus removal stage. The water produced by the method has a lower phosphorus concentration and a lower nitrogen concentration than the starting material water.

Various embodiments relate to an electrochemical cell for removal of materials from water and methods of using the same. A method of removing phosphorus from water includes immersing an electrochemical cell in water including phosphorus to form treated water including a salt that includes the phosphorus. The electrochemical cell includes an anode including Mg, Al, Fe, Zn, or a combination thereof, a cathode including Cu, Ni, Fe, or a combination thereof. The method includes separating the salt including the phosphorus from the treated water, to form separated water having a lower phosphorus concentration than the water including phosphorus.