A desalination system (100) having an intake unit (110) providing seawater to a pre-treatment unit (120) connected to a reverse osmosis (RO) desalination unit (130) and a post treatment unit (150). The desalination system (100) is configured to operate without any external addition of chemicals to simplify logistics and regulation concerns. The units of the system are configured to prevent biofouling, scaling and corrosion by mechanical and biological means including high flow speeds, biological flocculation of colloids, and making the water entering the RO units inhospitable to bacteria and other organisms that cause biofouling, hence preventing their settlement and removing them with the brine. Recovery rate is lowered and energy is recovered to increase the energetic efficiency and minerals that are added to the product water are taken from the brine.

A process for treating sour water includes combining the sour water with an alkali or alkaline metal hydroxide to produce a sour water mixture, the sour water comprising sulfides, passing an electric current through the sour water mixture, where passing the electric current through the sour water mixture causes at least a portion of the sulfides to react to produce a treated sour water comprising sulfates and having a pH of 7.1 to 9.8, saturating the at least a portion of the sulfates in an aqueous sulfate solution, and separating at least a portion of saturated sulfates from a saturated aqueous sulfate solution.

A system and method of treating sour water, including providing sour water having hydrosulfide ions and a carbon-containing compound to an anodic chamber of an electrolyzer vessel, converting the hydrosulfide ions into sulfate ions in the anodic chamber via an oxido half-reaction of a first oxido-reduction reaction and generating carbon dioxide in the anodic chamber via an oxido half-reaction of a second oxido-reduction reaction associated with the carbon-containing compound. The technique includes reacting the carbon dioxide with hydroxide ions in the anodic chamber to generate bicarbonate ions. The technique includes discharging an anodic chamber solution having the sulfate ions and the bicarbonate ions from the electrolyzer vessel from the anodic chamber.

An electrochemical wastewater treatment system comprises a reactor tank, an electrochemical reactor and a separation device which filters the effluent stream from the reactor tank and generates a treated wastewater stream and a reject stream which is at least partially fed to the electrochemical reactor or to the reactor tank to thereby increase the concentration of selected soluble and insoluble compounds within the reactor. A portion of the reject stream or a portion of the wastewater in the reactor tank can be discharged as a blowdown stream. Flow control means are provided for adjusting the volume of the reject stream and of the blowdown stream for controlling the compounds concentration. The concentration of soluble and insoluble compounds in the reactor is therefore decoupled from the concentration of the compounds in the reactor effluent stream to achieve an improved reactor performance and a higher quality effluent.

An electrochemical wastewater treatment system comprises a reactor tank, an electrochemical reactor and a separation device which filters the effluent stream from the reactor tank and generates a treated wastewater stream and a reject stream which is at least partially fed to the electrochemical reactor or to the reactor tank to thereby increase the concentration of selected soluble and insoluble compounds within the reactor. A portion of the reject stream or a portion of the wastewater in the reactor tank can be discharged as a blowdown stream. Flow control means are provided for adjusting the volume of the reject stream and of the blowdown stream for controlling the compounds concentration. The concentration of soluble and insoluble compounds in the reactor is therefore decoupled from the concentration of the compounds in the reactor effluent stream to achieve an improved reactor performance and a higher quality effluent.

A system for electrohydromodulation of wastewater. In an embodiment, the system comprises an anode in contact with at least one anodic chamber and a cathode in contact with a cathodic chamber. Each anodic chamber and the cathodic chamber are configured to receive a flow of wastewater. A first multivalent cation exchange membrane, between each anodic chamber and the cathodic chamber, allows multivalent cations to pass therethrough while preventing monovalent ions to pass therethrough. A power source is electrically coupled to each anode and the cathode, and is configured to apply a voltage across wastewater in the anodic chamber and the cathodic chamber, to thereby cause multivalent cations in the wastewater to pass through the multivalent cation exchange membrane.

A method, system and composition is described for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method, system and composition are used to create zero liquid discharge recycling.

Disclosed are systems and processes for the removal and conversion of pollutants in water. A system includes a set of electrodes with at least one electrode having an integrated catalyst material. The system is operatable in a first, electrodialysis mode in which one or more pollutants are separated from a feedwater stream, and a second electrolysis mode in which the separated pollutant(s) are catalytically converted into benign products by way of the catalyst material of the electrode. Electrodialysis and electrolysis are therefore carried out using the same unit.

Process for upgrading effluent treatment plants for pulp and paper production processes, where salts are removed from the effluent for water reuse and chemical recovery. The process comprises a first dialysis system for salt removal, a second treatment system for recovery or re-concentration, and optionally a post-treatment of the re-concentrate preventing liquid discharges to the environment. In the first system, a reversible electrodialysis or reversible pulsed step is carried out, separating the salts from the effluent, which are sent to the second treatment system to concentrate the salts (re-concentrate) or transform them into useful chemicals for the same process (recovery). Chemical recovery is achieved by electrodialysis with bipolar membranes or metathesis, to reduce the re-concentrate stream, which cannot be reused in the same plant. Lastly, this stream may be treated by spray drying, crystallization or evaporation.

An apparatus for the treatment of acid mine drainage and selective recovery of at least one of metals, critical elements, sulphuric acid and water is disclosed. The apparatus includes at least one electrochemical reactor, at least one catholyte reservoir and at least one anolyte reservoir for containing the acid mine drainage and a buffer, respectively. The reservoirs are in fluid communication with the at least one electrochemical reactor. The apparatus also includes at least one sensor for monitoring a pH of a contents of the reactor; and a power source for supplying an electrical current to the at least one electrochemical reactor. The electrical current is supplied until a predetermined pH is reached for the selective recovery of the at least one of metals, critical elements, sulphuric acid and water. A process for the treatment of acid mine drainage is also disclosed.