The present disclosure relates to methods of synthesizing slurries comprising ferrihydrite nanoparticles, and systems and methods employing the same. The method may include the steps of preparing an aqueous solution having ferric iron cations, halide anions, and a two-line iron promoter, and precipitating the ferrihydrite nanoparticles in the aqueous solution, thereby producing a ferrihydrite slurry. The ferrihydrite slurries may be useful in treating a polluted fluid having sulfur contaminants therein.

Methods for making a plurality of nanoparticles are provided. The method may include flowing a first component of the core into a reaction chamber; flowing a polymeric material into the reaction chamber; and flowing a second component of the core into the reaction chamber such that the first component reacts with the second component to form a core. The polymeric material forms a polymeric shell around the core.

There is provided a composite material comprising a porous silica particle, a plurality of metal particles disposed within the pores of said silica particle and a polymeric coating that at least partially encapsulates said silica particle. There is also provided a method of preparing a composite material, comprising the step of mixing a solution containing a plurality of activated metal and silica particles with a polymer solution to thereby form said composite material, wherein said composite material comprises a porous silica particle, a plurality of metal particles disposed within the pores of said silica particle and a polymeric coating that at least partially encapsulates said silica particle.

A filter media for the filtration of potable water; specifically, for the removal of arsenic from potable water using iron-impregnated activated carbon enhanced with titanium oxide, such as the titanium oxide mixture used in the commercial product Metsorb®. The activated carbon is subjected to a wet impregnation process using an iron salt solution of approximately 6% of iron(III) chloride FeCl.sub.3 solution and 1.25% of NaOH solution.

A system is provided for removing arsenic from water to safe levels at or below the EPA standards. The system is a hybrid spouted vessel/fixed bed filter system that significantly enhances/improves arsenic removal for drinking water using zero-valent iron (ZVI) particles. Movement of the circulating, iron-containing particles in a dense moving bed that forms on the spouted vessel bottom creates an abrasive “self-polishing” action among them that continuously generates colloidal iron corrosion products. This material then circulates with the water in the vessel and is removed and concentrated in a fixed bed filter. The colloidal material captured and immobilized in the filter has been shown to remove arsenic from contaminated water at very rapid rates.

A biodegradable iron-crosslinked alginate is useful as a remediation agent for environmental contaminants such as phosphate. When charged with phosphate, or other nutrients, the iron-functionalized alginate can be used as an agricultural fertilizer.

Industrial waste derived adsorbents were obtained by pyrolysis of sewage sludge, metal sludge, waste oil sludge and tobacco waste in some combination. The materials were used as media to remove hydrogen sulfide at room temperature in the presence of moisture. The initial and exhausted adsorbents after the breakthrough tests were characterized using sorption of nitrogen, thermal analysis, XRD, ICP, and surface pH measurements. Mixing tobacco and sludges result in a strong synergy enhancing the catalytic properties of adsorbents. During pyrolysis new mineral phases are formed as a result of solid state reaction between the components of the sludges. High temperature of pyrolysis is beneficial for the adsorbents due to the enhanced activation of carbonaceous phase and chemical stabilization of inorganic phase. Samples obtained at low temperature are sensitive to water, which deactivates their catalytic centers.

Disclosed is a novel adsorbent having excellent adsorption durability and high adsorption efficiency while having improved durability, thereby improving a carbon dioxide (CO2) separation process. A mesoporous cellular foam impregnated with an iron (Fe)-substituted heteropolyacid includes a mesoporous cellular foam support and an Fe-substituted heteropolyacid, and the mesoporous cellular foam impregnated with an Fe-substituted heteropolyacid has superior CO2 adsorption performance and exhibits excellent reproduction performance even after CO2 adsorption and desorption are performed several times through temperature changes, thereby enabling efficient and economical CO2 separation.

A process for producing black powder oxygen carriers for use in a chemical looping combustion unit includes the steps of: (a) removing and collecting the black powder waste material that was formed in a gas pipeline; (b) pre-treating the collected black powder to adjust its spherical shape to avoid attrition and fines production; and (c) activating the black powder to increase its reactivity rate and produce the black powder oxygen carrier that is suitable for use in the chemical looping combustion process as an oxygen carrier.

A liquid concentrate composition for remediation of groundwater, said composition consisting of powdered iron in the amount of 30 to 70% zero-valent iron powder, such as 40 wt, 1 to 15 wt % of water, 0.1 to 1.5% of surfactant and 40 to 70 wt % of the organic carrier, wherein the organic carrier is added to the 100 wt % and optionally, organic electron donor solution and/or remediation chemical, wherein organic electron donor solution and/or remediation chemical is not exceeding 10 wt % of the liquid concentrate.