A composition and process for reducing contaminants from water which includes use of a water-insoluble adsorbent having a surface area of at least about 10 m.sup.2/g, where the adsorbent is coated with a water-soluble metal salt.

Sensor and method for detecting, monitoring and/or removing trace amounts of heavy metal in a liquid. The sensor including magnetic nanoparticle composites of carbon nanotubes intercalated with CoFe.sub.2O.sub.4; the method including contacting a sample of liquid with the magnetic nanoparticle composites and measuring the X-ray diffraction and magnetic properties of the magnetic nanoparticle composite, where a statistical difference in the X-ray diffraction or magnetic properties of the magnetic nanoparticle composite before and after contact between said sample of said liquid and said magnetic nanoparticle composite indicates the presence of a heavy metal in said liquid.

A method of treating a waste liquid includes: 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 liquid property of a pH of 4 or less, and performing separation into a second treated water and gypsum; an aluminum and fluorine removal step of adding an alkali to the second treated water and performing separation into a third treated water and a precipitate containing aluminum and fluorine; and a neutralization step of adding an alkali to the third treated water and performing separation into an alkali neutralization treated water and a neutralized precipitate of a heavy metal hydroxide.

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.

The present invention provides a multi-stage filter system suitable for the production of drinking water from a wide variety of contaminated water sources. The modular nature of the multi-stage filter system allows for the customization of filter combinations according to the remediation requirements. The multi-stage filter system comprises a coarse filter (S1); an ultrafiltration filter (S2); a graphene-based filter (S3); and a residual nanoparticle filter (S4). The graphene-based filter cartridge comprises few-layer graphene powder; a combination of few-layer graphene powder and pellets comprising a mixture of polyethersulfone, graphene oxide (GO), and dimethylformamide; a composite comprising chitosan, GO, sodium sulfate and ferric chloride; or a combination of few-layer graphene powder, granular activated carbon and a composite comprising chitosan, GO, sodium sulfate and ferric chloride.

Methods and systems are provided for treating a contaminated environmental medium. In one example, the treatment includes adding a first jarosite-group mineral to the contaminated environmental medium to form a wet mixture under a set of conditions. The set of conditions is maintained over a duration of time to expedite precipitation of a second jarosite-group mineral, the second jarosite-group mineral incorporating contaminant cations and contaminant anions into a structure of the second jarosite-group mineral. The first jarosite-group mineral is added in situ at a contamination site.

The present subject matter illustrates a zero-valent metal suspension in non-aqueous phase. The suspension comprises 41 wt. % of a plurality of zero-valent iron particles; 0.1 wt % of a surfactant; 36 wt. % of an oil; and 23 wt. % of a thickening agent.

The present disclosure provides novel solid sorbents synthesized by the reaction of polyamines with polyaldehyde phosphorus dendrimer (P-dendrimer) compounds for metal sequestration. The sorbents are highly stable and exhibit desirable thermodynamics and reaction kinetics with a wide variety of metals including heavy metals and rare earth elements. The sorbents can be easily regenerated for repeated use to extract metals from an aqueous solution. The materials are stable to aqueous and organic media, as well as strong acid and bases. The sorbents maintain full capacity over many cycles of use.

The present disclosure relates to methods of treating water to remove contaminants, including harmful metal ions, and water treatment plants for practicing such methods. In an embodiment, the process includes adding a sulfur-containing, metal-decreasing agent; an iron (III)-containing, metalloid-decreasing agent; forming a solid precipitate from the contaminated water, wherein the solid precipitate includes a solid metal sulfide, a solid iron metalloid, a solid calcium metalloid, or a combination thereof; and separating the contaminated water from the solid precipitate to form purified water.

The present invention relates to a method for electrochemical purification of an aqueous solution comprising the steps of: providing a cathode and an anode to an aqueous solution, wherein said aqueous solution comprises soluble ions of at least one toxic heavy metal and wherein said cathode comprises an outer surface, which outer surface comprises a noble metal; applying an absolute potential to said cathode and wherein said absolute potential of said cathode drives the formation of an alloy comprising said noble metal and said at least one toxic heavy metal.