This disclosure relates to a method of fabricating a multivalent iron bio-inhibitor from waste bauxite residue and methods of controlling reservoir souring using the multivalent iron bio-inhibitor.

A nano zero valent iron biological coupling device for organic wastewater includes a continuous flow stirred reactor, a flocculation sedimentation device and a membrane bioreactor arranged in series. A nano zero valent iron feeding device is arranged in the continuous flow stirred reactor, a flocculant and a coagulant aid are arranged in the flocculation sedimentation device, and a microbial reaction liquid is arranged in the membrane bioreactor. A nano iron biological coupling process includes: S1, placing the organic wastewater in the continuous flow stirred reactor, adding the nano zero valent iron, stirring and mixing; S2, placing the organic wastewater treated after S1 in the flocculation sedimentation device; S3, placing the organic wastewater treated after S2 in the membrane bioreactor and interacting with the microbial reaction liquid; S4, performing a membrane separation on the organic wastewater treated after S3 in the membrane bioreactor to obtain purified organic wastewater.

The invention relates to a method for removing Cr(VI) ions from an aqueous electrolyte solution, particularly an electrolyte solution for electrochemical metal machining, which comprises the reduction of Cr(VI) to Cr(III) with Fe(II) ions. The Fe(II) ions are added to the electrolyte solution in the form of an aqueous salt solution which has been brought into contact with an ion exchange resin loaded with Fe(II) ions. The invention further relates to a device (1) for electrochemical machining of a workpiece (2) by means of an aqueous electrolyte solution (6), which has an ion exchanger (11) which has been loaded with an ion exchange resin charged with Fe(II) ions.

System and process for the treatment of water using a ferrate-based reduction-oxidation (redox) reactor, a clarifier, and a two-stage filtration system. Three treatment substrates can be used to treat water in the water treatment system and process, namely, a ferric compound(s), an acidic oxidant, and a flocculant-adsorbent.

Proposed are a photocatalyst, including titanium dioxide particles including titanium dioxide (TiO.sub.2), a carbon material located on all or part of the surface of the titanium dioxide particles and including at least one selected from the group consisting of graphene, reduced graphene oxide (rGO), and carbon nanotubes (CNTs), and bimetallic nanoparticles supported on the carbon material and including first metal nanoparticles and second metal nanoparticles, and a water treatment method using the same. In the photocatalyst and the water treatment method using the same, the photocatalyst including bimetallic nanoparticles and graphene oxide is prepared, thereby exhibiting high reduction efficiency and high selectivity to nitrogen gas even without the use of an external electron donor.

A method of generating hydrogen gas includes providing a colony of sulfur-reducing bacteria and a colony of sulfur-oxidizing bacteria. The colonies can be submerged in a body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid. The sulfuric acid can react with manganese to produce hydrogen gas and manganese sulfate.

A method of separating oxygen from a body of water includes providing a colony of denitrifying bacteria submerged in the body of water. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides present in the body of water to nitrogen gas. The method can also include collecting the nitrogen gas and bubbling the nitrogen gas through a portion of water from the body of water to remove dissolved oxygen from the portion of water. This can form a mixture of the nitrogen gas and oxygen gas.

Disclosed herein are a method for treating a water stream in a zero liquid discharge (ZLD) system and a ZLD system. The method includes contacting the water stream with a metal agent that reduces a nitrate contained therein to a nitrite, and introducing an amide into the water stream that reduces the nitrite to nitrogen to provide a treated water stream having a reduced nitrate concentration. The ZLD system includes a mix tank, an amide tank including an amide, and a crystallizer. The mix tank includes an inlet for receiving a water stream within the mix tank, and a container including a metal agent. The container is designed to allow the water stream to contact the metal agent. The amide tank is designed to direct the amide into the water stream, and the crystallizer is designed to receive the water stream from the mix tank.

A process for treating water contaminated with refractory organic matter, such as per- and polyfluoroalkyl substances (PFASs), comprising the following steps: (a) lowering the pH of the water for hydrolysis of organic matter; (b) subjecting the water with lowered pH to catalytic reduction by zero valent iron for organic matter degradation; (c) optionally aerating the water to oxidise the iron to ferric hydroxide; (d) optionally clarifying the water; and (e) optionally a catalytic advanced oxidation step. A system for conducting the process is also disclosed.

A riser bracket for supporting a riser board and a computer card inserted into the riser board is disclosed. The riser bracket includes a first riser bracket piece, a first latch, a second riser bracket piece, and a second latch. The computer card and the riser board are positioned on a motherboard. The first riser bracket piece is configured to be coupled to the riser board. The first latch is configured to the first riser bracket piece to a first mounting point of the motherboard, and to move between a latched position and an unlatched position. The second riser bracket piece is coupled to the first riser bracket piece. The second latch is configured to couple the second riser bracket piece to a second mounting point of the motherboard, and move between a latched position and an unlatched position.