Purification devices and methods remove perfluorinated compounds (PFCs) from PFC-contaminated water using temperature swing adsorption and desorption.

A water purification apparatus (300) capable of being cleaned at a point of care, and methods for cleaning the water purification apparatus (300) at the point of care. The water purification apparatus (300) and the methods provide an efficient use of a heater (302) for heat disinfection the water purification apparatus (300), e.g. by recirculating heated fluid to further heat the fluid. Several different cleaning programs are provided that may be utilized for cleaning different parts of the water purification apparatus (300).

A rare earth coated membrane is beneficial to aid in the separation of contaminants, such as anions containing phosphorous, anions containing arsenic, PFAS, and mixtures thereof. Membranes with the rare earth coating or treatment can have larger pore sizes than would be expected to remove these contaminants. Disclosed herein are methods for treating or coating the membrane to provide the rare earth coated membrane. The coated membranes can be used to remove contaminants, such as anions containing phosphorous, anions containing arsenic, and PFAS, from liquid feeds, such as water or water-based feeds.

It discloses a method for preparing a magnesium-aluminum hydrotalcite-loaded nano zero-valent iron material for specifically removing perfluorooctanoic acid in a water environment and an optimized process for removing perfluorooctanoic acid thereby, and relates to the technical field of removing persistent organic pollutants in water using adsorption method and oxidation-reduction method and, in particular, to a composite material prepared by loading a nano zero-valent iron on magnesium-aluminum hydrotalcite using liquid phase reduction method.

Per- and polyfluoroalkyl substances (PFAS) are destroyed by oxidation in supercritical conditions. PFAS in water is concentrated in a reverse osmosis step and salt from the resulting solution is removed in supercritical conditions prior to destruction of PFAS in supercritical conditions.

The invention regards a composite for environmental remediation, comprising: one or more green rust compound(s) or green rust precursor(s), andone or more biochar(s).

A water treatment system is disclosed. The water treatment system comprises a filtration module comprising one or more ultrafiltration membrane configured to remove one or more non-PFAS contaminant from a PFAS contaminated water stream to provide a partially purified water stream containing soluble PFAS contaminants. The water treatment system also comprises a sorption module comprising one or more sorption units comprising a sorbent material, the sorption module being in fluid communication with the filtration module and downstream therefrom and configured to remove substantially all PFAS contaminants from the partially purified water stream to provide purified water that is substantially free from PFAS contamination.

A method and system for removing non-aqueous phase liquids (NAPL) from geologic media below the surface of the ground, employing a flexible liner disposed down a borehole. A flexible carrier liner has an absorbent outer cover composed of a NAPL-absorbent outer layer and a NAPL-absorbent inner layer, both preferably hydrophobic. The liner with outer cover is placed down the borehole, preferably but not necessarily by eversion. Liner placement presses the absorbent outer layer against the borehole wall. NAPL in the groundwater adjacent the outer layer is absorbed into the outer layer and then wicked into the inner layer. The liner and outer cover can then be extracted from the borehole to remove from the subsurface the NAPL absorbed in the cover's absorbent layers. If portions of the liner are transparent, a down-hole camera may be deployed to monitor the degree of NAPL absorption in the absorbent inner layer.

A method is described for using basalt to selectively adsorb organic toxic materials, such as dioxins, furans, polychlorinated biphenyls (PCBs), bis(2-ethylhexyl)phthalate, arsenic, mercury, chromium, copper, nickel, zinc, cadmium, lead, and the like, from substances such as sediment, which contains water and the toxic materials. Optionally, the basalt may be in the form of a liner, a cap, or a filter that surrounds, contains, or contacts sediment contaminated with the organic toxic material(s).

A method for removing a fluorine-containing compound from discharge water, which includes bringing discharge water containing two or more fluorine-containing compounds represented by the following general formula (1) or (2) into contact with an adsorbent so as to adsorb the two or more fluorine-containing compounds:
(H(CF.sub.2).sub.mCOO).sub.pM.sup.1General Formula (1):
wherein m is 3 to 19, M.sup.1 is H, a metal atom, NR.sup.b.sub.4, where R.sup.b is the same or different and is H or an organic group having 1 to 10 carbon atoms, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and p is 1 or 2;
(H(CF.sub.2).sub.nSO.sub.3).sub.qM.sup.2General Formula (2):
wherein n is 4 to 20; M.sup.2 is H, a metal atom, NR.sup.b.sub.4, where R.sup.b is the same as above, imidazolium optionally having a substituent, pyridinium optionally having a substituent, or phosphonium optionally having a substituent; and q is 1 or 2.