Provided herein are methods and compositions for water disinfection. The methods and compositions, which can include a peracid and a source of copper ions, are useful for treatment of water contaminated with recalcitrant microbes.

A method and system is provided for treating waste generated from manufacturing operations including at least one of Printed Circuit Boards Fabrication (PCB FAB), General Metal Finishing (GMF), semiconductors manufacturing, chemical milling, and Physical Vapour Deposition (PVD). The method and system are used to create zero liquid discharge recycling.

There are provided methods for treating a gas having an undesirable odor. The methods comprise contacting the gas with an acidic aqueous oxidizing composition having a pH of about 2.0 to about 3.0 and comprising at least one cation of a metal; a sequestering agent; and H.sub.2O.sub.2 and submitting the gas and the composition to UV radiation when the gas and the composition are contacting each other, wherein the treatment permits to reduce by at least 60% intensity of the undesirable odor.

The disclosure provides a repairing material for emergency treatment of a black and odorous surface water environment and its preparation method, belonging to the fields of environmental science and engineering technology. The preparation method of the disclosure specifically includes the following steps: (1) uniformly stirring activated carbon, calcium chloride, ammonia water solution, polyethylene glycol and water in a stirrer, then dropwise adding hydrogen peroxide, and after the completion of the dropwise adding, obtaining a calcium peroxide repairing material solution; (2) adding a sodium hydroxide solution to the calcium peroxide repairing material solution obtained in step (1) until a pH reaches 11.5, thereby obtaining a suspension; (3) centrifuging the suspension in step (2) to obtain a solid; and (4) washing the solid in step (3) with distilled water until a final pH of residual water reaches 8.4, and then drying the obtained precipitate to obtain the repairing material. The repairing material of the disclosure has good treatment effect and high efficiency.

A composite nanomaterial of ZnO impregnated by, e.g., a green copper phthalocyanine compound (CuPc) can be an efficient solar light photocatalyst for water remediation. The composite may include hollow shell microspheres and hollow nanospheres of CuPc-ZnO. CuPc may function as a templating and/or structure modifying agent, e.g., for forming hollow microspheres and/or nanospheres of ZnO particles. The composite can photocatalyze the degradation of organic pollutants such as crystal violet (CV) and 2,4-dichlorophenoxyacetic acid as well as microbes in water under solar light irradiation. The ZnO—CuPc composite can be stable and recyclable under solar irradiation.

The present invention is directed to a composition in solution (often, an aqueous solution) which comprises a combination of molecular iodine (I.sub.2) and an acceptable source of iodate (IO.sub.3), and an acid (inorganic or organic), wherein iodide and iodate are present in the composition at a molar ratio of about 0.1 to about 25, the concentration of uncomplexed molecular iodine is a disinfectant, biocidal and/or antimicrobial (depending upon the end use of the composition) effective amount the concentration of acid in the composition is effective to provide a buffering pH in the composition ranging from about 1.5 to about 6.5. Compositions according to the present invention are storage stable for unexpectedly long periods of time (up to about 5 years), and find use as disinfecting solutions, as germicides and/or biocides (e.g. antiviral, antibacterial, antifungal, antispore etc.) for various surfaces and solutions including living and inanimate surfaces and are particularly useful because of their low cost, their reduced use of iodine, their activity (because of the high concentration of free molecular iodine in solution), their reduced environmental impact, their long term storage stability and their reduced toxicity. They also have particular utility in treating food surfaces to retard spoilage, increase useful shelf-life and minimize the human and economic cost of food waste. The compositions inactivate viruses, bacteria (both gram negative and positive), spores and fungi. Compositions according to the present invention may be used and stored in a variety of materials, given the substantial absence of corrosion (non-corrosive) these compositions display. Dental compositions (e.g. preprocedure rinses and other compositions) and methods related thereto are also disclosed.

Provided are a method of treating spent caustic occurring in a refinery process, a petrochemical process, and an environmental facility, and an apparatus thereof, wherein the spent caustic may be economically treated by a Fenton-like oxidation reaction at room temperature and atmospheric pressure in a reactor in which catalyst structures are stacked as compared to conventional methods of treating spent caustic.

A method of degrading 1,4-dioxane in the wastewater produced during the manufacture of alkyl ether sulfates is disclosed. The method includes the steps of (a) mixing from 100 to 10,000 ppm, preferably 1,000 to 4,000 ppm of ozone with the wastewater; (b) introducing H.sub.2O.sub.2 into the wastewater in an amount of 0.01 to 10, preferably 0.1 to 0.5 molar equivalents of H.sub.2O.sub.2 to ozone, and (c) mixing the ozone, H.sub.2O.sub.2, and wastewater to generate hydroxyl radicals reactive with the 1,4-dioxane, without the addition of a metal catalyst. The hydroxyl radicals react with the 1,4-dioxane and degrade it into carbon dioxide, water and/or carbonate. The method is effective to reduce a concentration of 1,4-dioxane in the wastewater from a range of about 10 ppm to about 1000 ppm of dioxane down to less than 5 ppb of 1,4-dioxane after treatment. The method is also effective for removing hydrocarbon species that may be present in the wastewater.

A method of purifying a produced water comprising contacting a produced water stream with a composition comprising a (i) a chelant; (ii) an oxidizing agent; and (iii) a surfactant under conditions suitable for the formation of a purified produced water. A composition for purifying produced water comprising (i) a biochelant in an amount of from about 1 wt. % to about 10 wt. %: (ii) an oxidizing agent in an amount of from about 3 wt. % to about 50 wt. %; (iii) a surfactant in an amount of from about 0.1 wt. % to about 70 wt. % wherein the weight percentage is based on the total weight of the composition; and (iv) a solvent.

A method for removing silica from an aqueous solution is provided. The method includes steps of flowing the aqueous solution into an electro-Fenton reactor, wherein the reactor comprises one or more electrodes in a bipolar arrangement positioned between a monopolar iron anode and a monopolar cathode; applying an electric current to the aqueous solution such that silica aggregates form on ferric hydroxide; and removing the silica aggregates from the aqueous solution.