Methods of treating a water sample containing both free fluoride and fluorinated organic compounds are described. The methods are effective at removing high amounts of the free fluoride while retaining high amounts of the fluorinated organic compounds. The methods include combining the water sample with a hexaalkyldisiloxane, a strong acid and a compatibilizing solvent; reacting the free fluoride with the disiloxane; and removing the fluorinated reaction product.

A method of treating a waste liquid: an aluminum dissolution step of dissolving aluminum in an acidic waste liquid and performing separation into a first treated water and a reduced heavy metal precipitate; a gypsum recovery step of adding a calcium compound to the first treated water at a pH of 4 or less, and performing separation into a second treated water and gypsum; a heavy metal coprecipitation step of adding a ferric compound to the second treated water and performing separation into a third treated water and a heavy metal coprecipitate; an aluminum and fluorine removal step of adding an alkali to the third treated water and performing separation into a fourth treated water and a precipitate containing aluminum and fluorine; and a neutralization step of adding an alkali to the fourth treated water and performing separation into an alkali neutralization treated water and a neutralized heavy metal hydroxide.

Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

A composition for treating water including an organic soil amendment and having ions bound thereto is beneficial to aid in the removal of aqueous contaminants, such as phosphate, other phosphorus containing compounds, arsenic, arsenic containing compounds, fluorides, and PFAS from water. In these compositions the ions include rare earth cations, iron cations, and mixtures thereof. There are also methods for making these soil amendment compositions, as well as methods for using these compositions to effectively remove contaminants from water.

A sewage treatment device includes a fluidized bed body, a reflux device and a chemical feeding device. The fluidized bed body is sequentially provided with a sedimentation zone, a transition zone and a fluidization zone from top to bottom. The reflux device is connected to the fluidized bed body through a reflux pipe. The reflux pipe extends into the fluidized bed body from the sedimentation zone, and the granularity of a crystal product can be controlled by changing the height of a reflux inlet at the bottom end of the reflux pipe in the fluidized bed body. By controlling the position of the reflux inlet of the reflux pipe in the fluidized bed body, combining product granularity requirements, and adjusting an insertion depth of the reflux pipe, the granularity of a final product can be flexibly regulated and controlled, and meanwhile, a product recovery rate is improved.

Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

A process for rendering excavation material inert for the purpose of their analysis, of their storage and/or of their valorisation. The process for inerting the excavation material includes adding an organic acid, of a complexing agent or of a diaminotetracarboxylic acid to the excavation material, the complexing agent being chosen from a sugar alcohol, a cationic surface-active agent and their mixtures. Also, a method of determining the concentration by weight of a polluting inorganic element included in an excavated material, a method of storage of the inert excavation material, and a method of valorising the inerted material.

A device for selectively removing a perfluorinated compound may include an adsorption electrooxidation tank including a reaction unit having a plurality of electrodes and granular activated carbon configured to oxidize and decompose a perfluorinated compound in raw water through adsorption and electrooxidation, a power supply device configured to supply power to the adsorption electrooxidation tank, and a head adjustment pipe unit configured to maintain a water level within the reaction unit at a height greater than or equal to a reaction height of the electrode.

The disclosure provides a porous polymeric membrane having ionizable nitrogen functional groups at least at its surface, wherein such groups are associated with a hydroxide anion. The membranes are useful in the purification of polar solvents such as water and alcohols and are capable of removing trace amounts of anionic contaminants such as halides, phosphates, nitrates, nitrites, sulfites, and sulfates.

A SCWO reactor fouling prevention and mitigation system that includes at least one feedstock tee which provides a feedstock to the SCWO reactor, at least one feedstock tee pressure sensor, such that each of the at least one feedstock tee has one of the at least one feedstock tee pressure sensor, at least one pressure sensor proximate a SCWO reactor inlet, and at least one pressure sensor proximate a SCWO reactor outlet. Also included is a controller which triggers a Clean In Place (CIP) procedure when there is a pressure difference between any two of the following, the SCWO reactor inlet, the at least one feedstock tee, and the SCWO reactor outlet. The CIP procedure includes washing a portion of the SCWO reactor with a fluid supplied through the at least one feedstock tee.