Perfluorinated and polyfluorinated compounds in an effluent stream are destroyed by means of electro-oxidation. Although electro-oxidation can be used to directly treat effluent, a more efficient use is to pre-concentrate applicable pollutants with filters or sorbents. Concentrated perfluorinated and polyfluorinated compounds are removed from the filter or sorbent with a regenerant solution and treated by electro-oxidation. A current density of 0.5 mA/cm.sup.2 or 1 mA/cm.sup.2 effectively reduces the level of perfluorinated contaminants within 1-3 hr. using a titanium electrode. This allows both the regenerant and filter or sorbent to be reused and greatly reduces the amount of material that must be treated as hazardous waste.

A waste treatment system for separating contaminants including per-fluoroalkyl and poly-fluoroalkyl substances (PFAS) from bulk solid waste (12). A preparation module (9) having a bulk material separator separates oversize material (14) from bulk solid waste (12). A physical separation module (13), located down-stream of the preparation module (9), separates the bulk solid waste (12) based on particle size using physical and/or hydrodynamic and/or density separation techniques. An extraction/chemical separation module (19), located downstream of the physical separation module (13), adds leachate and/or extractant to separate the contaminants from a slurry output from the physical separation module (13), into a fines output and a contaminated water solution. A water circulation system (21) supplies water to the physical separation module (13) and the extraction/chemical separation module (19), the water circulation system including at least one water treatment process, the treated water being recycled and recirculated within the waste treatment system.

The disclosure relates to modified wood pulp and methods using the same for removal for per- and polyfluoroalkyl substances (collectively “PFAS”) from contaminated water. Cationic-modified wood pulp can be used to adsorb anionic PFAS contaminants from water, and anionic-modified wood pulp can be used to adsorb cationic PFAS contaminants from water. The modified wood pulp has high adsorption efficiencies, rapid adsorption kinetics, and high adsorption efficiencies for a range of different PFAS contaminants.

A predictive system for monitoring fouling of membranes of a desalination or water softening plant includes ultrafiltration (UF) membranes, reverse osmosis (RO) membranes, and/or nanofiltration (NF) membranes. In addition, the system includes one or more UF skids including a plurality of UF units. Each UF unit contains therein a plurality of UF membranes. Further, the system includes one or more RO/NF skids including one or more RO/NF arrays. Each of the one or more RO/NF arrays includes a plurality of RO units, with each RO unit containing therein a plurality of RO membranes, a plurality of NF units, with each NF unit containing therein a plurality of NF membranes, or a combination thereof. Still further, the system includes UF sensors and/or RO/NF sensors. The system also includes a controller comprising a processor in signal communication with the UF sensors and/or the RO/NF sensors.

A high salinity water purification system and process, including a forward osmosis system and a reverse osmosis or nanofiltration system. A concentrated brine of a zinc or iron complex combined with a salt or acid draws pure water across the FO membrane from the influent water. The diluted brine is pumped through a vessel holding an anionic adsorption media to remove the zinc or iron complex and the resultant brine is passed through the RO or nanofiltration system to obtain purified water and a concentrated brine stream. The adsorption media is regenerated by a rinse cycle using fresh water or water from the RO system, removing the zinc or iron complex adhered to the media. The resultant brine is stored and mixed with the output of the RO system. Charged membrane can be used as a standalone membrane in FO process or in combination with resin or resin embedded membrane.

A method includes: (1) using a chelating agent, extracting divalent ions from a brine solution as complexes of the chelating agent and the divalent ions; (2) using a weak acid, regenerating the chelating agent and producing a divalent ion salt solution; and (3) introducing carbon dioxide to the divalent ion salt solution to induce precipitation of the divalent ions as a carbonate salt. Another method includes: (1) combining water with carbon dioxide to produce a carbon dioxide solution; (2) introducing an ion exchanger to the carbon dioxide solution to induce exchange of alkali metal cations included in the ion exchanger with protons included in the carbon dioxide solution and to produce a bicarbonate salt solution of the alkali metal cations; and (3) introducing a brine solution to the bicarbonate salt solution to induce precipitation of divalent ions from the brine solution as a carbonate salt.

A filter device may include a tank, a drainage section at a lower most end of the tank, a filter medium above the drainage section and below an upper most end of the tank, and a plurality of sensors provided on the tank. A first sensor may be configured to measure a first height of the filter medium. A second sensor and third sensor may be configured to measure a second height of fluids within the tank. Additionally, air is configured to be pumped through the filter medium during an air scouring cycle. A control system may be operational coupled to the filter device, the control system may be configured to maintain the fluids at the second height at a predetermined distance of one inch above the first height during the air scouring cycle.

A compound having the following structure:

##STR00001##

wherein: R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 are independently selected from (i) hydrogen atom, (ii) hydrocarbon groups (R) containing 1-30 carbon atoms and optionally substituted with one or more fluorine atoms, (iii) —OR′ groups, (iv) —NR′.sub.2 groups, (v) —C(O)R′ groups, and (vi) halogen atoms, wherein R′ groups are independently selected from R groups and hydrogen atoms, and wherein the R group optionally includes a C(O), ether, or amino linkage; X.sup.m− is an anionic species with a magnitude of charge m, where m is an integer of at least 1; and n is a number, provided that n×m=1. Also described herein are methods for removing one or more oxyanions from a liquid source by use of the above compound or mono-pyridyl derivative thereof.

A water intake and pretreatment system (10) comprising an inlet for delivering water from a natural source to a reservoir (12); said inlet to reservoir having a net screen (16) to prevent entry of organisms above a predetermined size and including a one-way gate (30) to allow organisms to exit the reservoir; said reservoir further comprising a granular filter media for water and algae filtration; and a drainage layer for removal of filtered water from the granular filter media to a drainage outlet. A local backwashing apparatus (40) is included for localized backwashing of the granular filter media.

The invention concerns an underwater water treatment unit which has specific cleaning means which are suitable for cleaning filtration membranes in the unconventional conditions associated with use at great or very great depths, as well as a method for cleaning the membrane of the underwater water treatment unit.