A method for remediating wastewater formed by water and per- and poly-fluoroalkyl substances (PFAS) using a wastewater treatment system that includes a collecting unit, a dewatering unit, a drying unit, and a baking unit. Wastewater provided to the collecting unit is dosed by adding a compound to the wastewater in an amount that is sufficient to cause the PFAS to separate from the water and to form a sludge. The sludge is dewatered with the dewatering from a first dryness level a second dryness level. The dewatered sludge is then dried in the drying unit from the first dryness level to a third dryness level. The dried sludge is then baked at a sufficiently high enough temperature that chemical bonds of at least a portion of the PFAS is destroyed.

A preparation method and application of a zero-valent aluminum/iron-bearing clay composite for catalyzing a persulfate to oxidize organics are provided, which belongs to the field of water environmental treatment. A novel catalyst is prepared by an iron-bearing clay and a zero-valent aluminum through a simple ball milling method, for achieving the effect of activating a persulfate to efficiently oxidize and degrade refractory organics in water. The preparation method and operation process thereof are simple. Compared with a chemical synthesis method, the method of the present disclosure brings about less secondary pollution, and has a shorter synthesis time, higher yield and lower cost. The modified material is the natural iron-bearing clay, which is widely available, non-toxic and stable as a heterogeneous catalyst.

A system for treating a source of water contaminated with PFAS is disclosed. The system includes a PFAS separation stage having an inlet fluidly connectable to the source of water contaminated with PFAS, a diluate outlet, and a concentrate outlet and a PFAS elimination stage positioned downstream of the PFAS separation stage and having an inlet fluidly connected to an outlet of the PFAS separation stage, the elimination of the PFAS occurring onsite with respect to the source of water contaminated with PFAS, with the system maintaining an elimination rate of PFAS greater than about 99%. A method of treating water contaminated with PFAS is also disclosed. The method includes introducing contaminated water from a source of water contaminated with a first concentration of PFAS to an inlet of a

PFAS separation stage, treating the contaminated water in the PFAS separation stage to produce a product water substantially free of PFAS and a PFAS concentrate having a second PFAS concentration greater than the first PFAS concentration, introducing the PFAS concentrate to an inlet of a PFAS elimination stage; and activating the PFAS elimination stage to eliminate the PFAS in the PFAS concentrate. A method of retrofitting a water treatment system as described herein is also disclosed. The method includes providing a PFAS elimination module as described herein and fluidly connecting the PFAS elimination module downstream of a PFAS separation stage.

A reactor system for decomposing at least one of a per- or polyfluoroalkyl substance (PFAS) is provided. The system includes a material having an interior surface that defines a compartment; a subaqueous liquid in the compartment; and an electron donor in the subaqueous liquid, the electron donor configured to release a hydrated electron upon ultraviolet (UV) irradiation. The reactor system is configured so that when the electron donor releases a hydrated electron into the subaqueous liquid, the hydrated electron has a longer lifespan relative to an electron released in normal bulk phase water, and when a PFAS is present within the subaqueous liquid, the hydrated electron is capable of reductively defluorinating the PFAS and to generate fluoride ions (F). A method of operating the system to decompose PFAS is also provided.

A process for preparing a granular composite adsorbent, that includes combining poly (diallyl dimethyl ammonium halide) and a clay mineral in water, maintaining the mixture under stirring, recovering a wet mass, forming the wet mass into granules and drying the granules to obtain the granular adsorbent having surface layer with positive zeta potential. The granular material and methods using the granular material in water treatment are also disclosed.

The disclosure is a method for recovering groundwater contaminated with organic phenols. The method includes the step of injecting a remediation agent into the groundwater extracted from the stratum to be rehabilitated or ex-situ extracted, followed by the step of injecting manganese-based oxidant. By adding a suitable proportion of soluble silicon to the water to be treated as a remediation agent, the efficiency of manganese-based oxidant in the treatment of phenolic pollutants is enhanced based on interface properties and stability of various manganese oxides in the regulating and recovering process. The method for recovering groundwater contaminated with organic phenols provided by the disclosure has a simple process and is convenient to operate, the adopted chemicals are inexpensive and easy to obtain, cause little corrosion to the injection equipment, and has a wide range of applications in practice. The adopted oxidant will not produce halogenated toxic by-products during the treatment process.

The invention relates to a process for working up water containing 4,4′-dichlorodiphenyl sulfoxide and/or 4,4′-dichlorodiphenyl sulfone as impurities, comprising: (a) mixing the water containing 4,4′-dichlorodiphenyl sulfoxide and/or 4,4′-dichlorodiphenyl sulfone as impurities with an organic solvent in which 4,4′-dichlorodiphenyl sulfoxide and/or 4,4′-dichlorodiphenyl sulfone have a solubility of at least 0.5 wt % based on the amount of 4,4′-dichlorodiphenyl sulfoxide and/or 4, 4′-dichlorodiphenyl sulfone and organic solvent at 20° C., which forms a two-phase system with water and which can be stripped from water with a stripping gas and subsequently separating the obtained mixture into an aqueous phase and an organic phase, and (b) stripping the organic solvent from the aqueous phase with a stripping gas.

The present disclosure provides methods, electrodes, and systems for electrochemical oxidation of polyfluoroalkyl and perfluroalkyl (PFAS) contaminants using Magnéli phase titanium suboxide ceramic electrodes/membranes. Magneli phase titanium suboxide ceramic electrodes/membranes can be porous and can be included in reactive electrochemical membrane filtration systems for filtration, concentration, and oxidation of PFASs and other contaminants.

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.

The presently disclosed subject matter is generally directed to a system and method of reducing, reacting, and/or removing an oxidant or unwanted chemical species from a chemical stream. Particularly, the system and method include the use of one or more reductants that react with the undesired chemical species. The reductant and the chemical stream are added to a reactor and allowed to react for a desired amount of time. The reductant will reduce, react with, and/or remove the chemical species from the stream. The excess reductant and reaction products are then removed from the reactor, as described in more detail herein below.