Described herein is a method of using hollow fiber filter cartridge. The method includes: providing a hollow fiber filter cartridge inside or outside an environmental cleaning equipment; allowing a wastewater to enter the hollow fiber filter cartridge from an outside of the hollow fiber filter under no water pressure or low water pressure (such as under 30 gw/cm.sup.2); allowing the wastewater to cross a plurality of nanopores of the hollow fiber filter cartridge under no water pressure or low water pressure (such as under 30 gw/cm.sup.2) to produce a clean water; and allowing the environmental cleaning equipment to filter wastewater to produce clean water continuously, thereby improving cleaning efficiency and reducing water consumption.

A feed of at least one of (a) a source liquid including a solvent with a dissolved impurity and (b) a retentate of the source liquid is pumped in a substantially closed loop through a liquid-separation module. The liquid-separation module includes a membrane that passes at least partially purified solvent to a permeate side of the membrane while diverting the impurity in a retentate on the retentate side of the membrane. The purified solvent is extracted from the permeate side of the membrane; and the retentate from the liquid-separation module is pumped to or through a pressurized reservoir with a variable volume for the feed component and recirculated as a component of the feed. Over time, the volume for the feed is reduced and the pressure applied to the feed in the reservoir is increased to balance against an increasing difference in osmotic pressure across the membrane.

A system for a carbon neutral cycle of gas production includes a molten salt reactor configured to generate zero carbon dioxide (CO.sub.2) emissions electricity. The system includes a desalination unit configured to receive the zero-CO.sub.2 emissions electricity from the molten salt reactor and produce a desalinated water. The system includes an electrolysis unit configured to be powered by the zero-CO.sub.2 emissions electricity generated by the molten salt reactor and generate hydrogen (H.sub.2) and oxygen (O.sub.2) from the desalinated water. The system includes an oxy-combustion unit configured to receive and combust a hydrocarbon fuel with the O.sub.2 from the electrolysis unit to produce electricity and CO.sub.2. The system includes a CO.sub.2 capture system adapted to capture the CO.sub.2 produced by the oxy-combustion unit and a catalytic hydrogenation unit configured to receive and convert H.sub.2 from the electrolysis unit and CO.sub.2 from the CO.sub.2 capture system to produce the hydrocarbon fuel.

Methods, systems, and techniques for removal of PFAS contaminants from contaminated soil or sediment are provided. Example embodiments provide a water-based ex-situ method and system at a site that utilizes particle size and particle density segregation; deagglomeration, attrition, and retention time and sequential contacts with purified water; a recirculating water system with continual water treatment, and additional modules for destructive treatment of concentrated PFAS. In an example embodiment, the water treatment system of an example PFAS contaminant removal system and process includes ion exchange resin filtration component to remove PFAS effectively.

A nanofiltration membrane with a high flux for selectively removing hydrophobic endocrine disrupting chemicals and a preparation method thereof are provided. The method includes the following steps: immersing a porous support layer into a first solution, removing excess droplets from a surface of the support layer after taking the support layer out of the first solution, and then immersing the support layer attached with the first solution into a second solution for an interfacial polymerization reaction, followed by washing after completion of the reaction to obtain the subject nanofiltration membrane. The first solution is an aqueous solution containing a polyamine monomer and an acid binding agent, and the second solution is an organic solution containing an acid chloride monomer and a metal-organic framework.

A method for selectively optimizing water chemistry within a wellbore may include positioning a system tubing in the wellbore. The system tubing may include an electrochemical cell, a first chamber, and a second chamber. The method may also include injecting a fluid into the electrochemical cell and directing an electrical current into the electrochemical cell wherein the fluid separates by charge into a first fluid and a second fluid. The method may also include passing the first fluid into the first chamber and the second fluid into the second chamber. Also, the method may include rotating the system tubing, wherein the first fluid flows from the first chamber to the wellbore though a first radial conduit and the second fluid flows from the second chamber to the wellbore through a second radial conduit.

An integrated utility system, comprising: at least one heat pump which includes a compressor for processing water mist from an evaporator and providing the water mist to a condenser; a thermal reservoir configured to contain water and operatively connected to the condenser; a heat management system configured to receive and process excess heat generated between the thermal reservoir and condenser. The heat management system comprises: a plurality of sensors for measuring water pressure, temperature and flow; at least one control valve for controlling movement of a thermal energy from thermal sources; at least one thermal sink; a thermal storage; a plurality of heat exchangers fluidly connected to the thermal sources, to the at least one thermal sinks, to the thermal reservoir and to a plurality of pumps configured to circulate a heat exchange fluid between the thermal sources, thermal reservoir and the at least one thermal sink.

A high salinity feed water such as seawater is treated to produce a reverse osmosis (RO) concentrate and an RO permeate. Optionally, some or all of the RO concentrate may be filtered to produce a nanofiltration (NF) permeate. Optionally, some feed water can also be filtered to produce NF permeate without first being concentrated by RO treatment. The NF permeate, or a blend of the RO permeate and NF permeate, may be used to produce a product water for injection into an oil-bearing reservoir to enhance oil recovery. Optionally, the product water may have salinity greater than the feedwater, or at least 30 g/L. The product water may have hardness of less than 20 mg/L.

A system for separating competing anions from per- and polyfluoroalkyl substances (PFAS) in a flow of water contaminated with PFAS and elevated levels of competing anions that includes a separation subsystem which receives the flow of water contaminated with PFAS and elevated levels of competing anions and separates competing anions from the PFAS and concentrates the PFAS to produce a treated flow of water having separated competing anions therein and a flow of water having a majority of PFAS therein. At least one anion exchange vessel having an anion exchange resin therein receives the flow of water having a majority of PFAS therein and removes PFAS from the water to produce a flow of treated water having a majority of the PFAS removed. The separation of competing anions by the separation subsystem increases the treatment capacity of the anion exchange resin to remove PFAS from the contaminated water.

The system for harvesting minerals from desalination brine includes a desalination module for receiving a stream of saltwater and producing a stream of purified water and a stream of desalination brine. A separator receives a first portion of the stream of desalination brine and separates monovalent ions from multivalent ions in the stream of desalination brine. The separator outputs a reject stream including the multivalent ions and a permeate stream including the monovalent ions. A membrane brine concentrator receives the permeate stream and produces a stream of lower concentration saltwater and a stream of higher concentration salt brine. The stream of lower concentration saltwater is mixed with the stream of saltwater received by the desalination module. A crystallizer receives the stream of higher concentration salt brine and produces a crystallized mineral product and a stream of bitterns.