Dangerous, toxic, and/or radioactive volatiles are produced from nuclear fission, nuclear decay, and/or as a byproduct from vitrification of radioactive wastes. Such volatiles are treated during and after vitrification of the radioactive waste, to be converted into fixed-chemicals, that are retained in, on, and/or proximate to a cold-cap located vertically above vitrified melt. The cold-cap may have one or more volatile fixing additives (VFAs) for retaining the fixed-chemicals. The VFAs are located in and/or the cold-cap. The vitrification may occur within at least one human-made cavern. The human-made cavern may be located within a deep geologic rock formation. The deep geologic rock formation may be located at least 2,000 feet below a terrestrial surface of the Earth. The human-made cavern may be formed by first drilling a wellbore from the terrestrial surface to the deep geologic rock formation and then underreaming the wellbore into the deep geologic rock formation.

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.

Dry processes, apparatus, compositions and systems are provided for reducing emissions of sulfur oxides, and sulfur dioxide in particular, and/or HCl and/or Hg in a process employing a combination of a lime-based sorbent, in particular hydrated lime and/or dolomitic hydrated lime, and a sorbent doping agent administered to achieve coverage of a three-dimensional cross section of a passage carrying SO.sub.x and/or HCl and/or Hg-containing gases with a short but effective residence time at a temperature effective to provide significant sulfur dioxide and/or HCl and/or Hg reductions with high rates of reaction and sorbent utilization. The once-through, dry process can advantageously introduce the sorbent and sorbent doping agent dry or preferably as a slurry to enable uniform treatment. Preferred sorbent doping agents include water-soluble or water-dispersible copper and/or iron compositions which can be heated to an active form in situ by the flue gases being treated.

A material for moisture removal and/or water harvesting from air may include a hydrophilic material containing micropores and a low water activity material confined within the micropores of the hydrophilic material. Apparatuses containing such materials and methods for moisture removal and/or water harvesting from air by using such materials are also described.

A lactic acid adsorbent includes a layered double hydroxide that contains multiple metal hydroxide layers and also contains anions and water molecules held between the metal hydroxide layers. The anions include (i) an amino acid such as glutamine, (ii) a dipeptide constituted by one or two kinds of amino acids such as glutamine, (iii) a vitamin such as ascorbic acid 2-phosphate, (iv) a pH buffer such as MES, (v) a glucose metabolite such as pyruvic acid, or (vi) inorganic ions selected from a group including NO.sub.3.sup.− and Cl.sup.−.

An article for removing undesired chemical ions or compounds from gas and fluid streams where the article is a porous polymeric matrix with a sorption particle, the sorption particle is capable of removing the undesired chemical ion or compound.

An atmospheric water harvesting material includes a deliquescent salt, a photothermal agent, and a polymeric hydrogel matrix containing the deliquescent salt and photothermal agent.

Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

A method for preparing an anion adsorbent may be provided, which comprises the steps of: mixing at least two metal salts with each other, thereby forming a stack structure in which cationic compound layers and anionic compound layers containing anions and water of crystallization are alternately stacked on one another; performing a first heat treatment on the stack structure to expand between the cationic compound layers, thereby preparing a preliminary anion adsorbent; and performing a second heat treatment on the preliminary anion adsorbent to remove the anions and the water of crystallization from the anionic compound layers while allowing at least one of the anions to remain, thereby preparing the anion adsorbent.