The sunlight active composite photocatalyst for water purification includes ZnO (zinc oxide) and Co.sub.3O.sub.4 (cobalt II, III oxide). The composite photocatalyst may, in the presence of natural sunlight, achieve complete mineralization of chemical and biological contaminants in water without leaving any hazardous by-products. The composite photocatalyst may be synthesized by a sol gel route or process.

A method for treating contaminant within contaminated soil and groundwater, especially deep aquifers, through in situ oxidative remediation of the contaminant by sparging, wherein the method includes multiple injection wells, injecting an oxidizing multi gas comprised of high concentration ozone gas (10-20% ozone by wt., 75-85% oxygen) at pressures up to 500 psi (34.5 bar) to reach well depths in excess of 1100 feet (335 meters) and when necessary compressed ambient air at pressures up to 500 psi (34.5 bar).

A system for treatment of a polluted effluent, includes an outer chamber configured to treat the polluted effluent in mixture with a purification slurry including particles of one or more catalysts and/or organoclays, or a mixture thereof. The outer chamber includes (i) a stirring unit consisting of an engine and a stirrer, configured to mix the polluted effluent and the purification slurry to prevent the particles from sinking without causing a turbulence, (ii) a membrane located at the top of the outer chamber through which a treated effluent passes, while preventing the particles of one or more catalysts and/or organoclays from exiting the outer chamber together with the treated effluent, (iii) a membrane cleaning system configured to remove and collect the particles of one or more catalysts and/or organoclays accumulated on the membrane, and re-introducing the particles back to the bottom of the outer chamber.

A system for treatment of a polluted effluent, includes an outer chamber configured to treat the polluted effluent in mixture with a purification slurry including particles of one or more catalysts and/or organoclays, or a mixture thereof. The outer chamber includes (i) a stirring unit consisting of an engine and a stirrer, configured to mix the polluted effluent and the purification slurry to prevent the particles from sinking without causing a turbulence, (ii) a membrane located at the top of the outer chamber through which a treated effluent passes, while preventing the particles of one or more catalysts and/or organoclays from exiting the outer chamber together with the treated effluent, (iii) a membrane cleaning system configured to remove and collect the particles of one or more catalysts and/or organoclays accumulated on the membrane, and re-introducing the particles back to the bottom of the outer chamber.

The present disclosure provides systems and methods for increasing the oxygen concentration of a water supply. The systems generally include a water supply and an electrolyzer module that generates oxygen to be added to the water supply. The methods generally include generating oxygen using an electrolyzer module and adding the generated oxygen to a water supply.

An indirect heat transfer supercritical water oxidation system includes a supercritical water oxidation reactant system and an intermediate medium circuit. A control method thereof includes controlling two-process pressure and temperature increase, controlling pressure and temperature decrease and controlling normal operation. The present invention focuses on automatic control strategy of engineering practice of the indirect heat transfer supercritical water oxidation system. The system heating process adopts the idea of circulating heating, which effectively reduces the investment of the heating equipment avoids the mismatch between the working pressure of the two processes, and ensures effectiveness of the heat transfer between supercritical pressure fluid in the inner tube and the outer tube of the preheater/heat exchanger during subsequent heating process. The effective control of a reaction temperature and overpressure protection of critical equipment ensure a process effect and system safety.

A method of remediating groundwater by injection a first aqueous solution and then a second aqueous solution into a well situated within the area of the groundwater to be remediated. The first aqueous solution comprises an iron ligand while the second aqueous solution comprises an oxidizing agent. It is envisioned that the ppm ratio of the iron ligand to oxidizing agent ranges from about 0.0005 to about 0.1.

A method of treating wastewater can include introducing wastewater into a wastewater treatment apparatus through a wastewater inlet. The wastewater can be compressed and decompressed via a mechanical pressurizing element and subsequently discharged from the wastewater treatment apparatus via a treated water outlet. The pressure cycling wastewater treatment apparatus can include a confined chamber which encloses an interior volume. The confined chamber can have a wastewater inlet through which wastewater can flow into the confined chamber. In addition, an expansion fluid inlet can receive an expansion fluid into the confined chamber. A treated water outlet can allow treated water to flow out of the confined chamber. Within the interior volume of the confined chamber, a mechanical pressurizing element can be configured to move in a cyclical pattern. Motion of the mechanical pressurizing element can cyclically compress and decompress a mixture of wastewater and expansion fluid inside the confined chamber for a desired number of cycles.

A method of treating wastewater can include introducing wastewater into a wastewater treatment apparatus through a wastewater inlet. The wastewater can be compressed and decompressed via a mechanical pressurizing element and subsequently discharged from the wastewater treatment apparatus via a treated water outlet. The pressure cycling wastewater treatment apparatus can include a confined chamber which encloses an interior volume. The confined chamber can have a wastewater inlet through which wastewater can flow into the confined chamber. In addition, an expansion fluid inlet can receive an expansion fluid into the confined chamber. A treated water outlet can allow treated water to flow out of the confined chamber. Within the interior volume of the confined chamber, a mechanical pressurizing element can be configured to move in a cyclical pattern. Motion of the mechanical pressurizing element can cyclically compress and decompress a mixture of wastewater and expansion fluid inside the confined chamber for a desired number of cycles.

A photocatalytic composition is disclosed that includes a silver halide in combination with one or more rare earth elements. The composition may be used for the photocatalytic degradation of pollutants.