A reverse osmosis prefilter system includes a recirculation chamber for accommodating one or more prefilter cartridges. The recirculation chamber is communicably interconnected to an inline water source and an RO filtration membrane. The recirculation chamber has a recirculation outlet and inlet which are communicably interconnected by an offline pump that recirculates prefiltered water repeatedly through the recirculation chamber and prefilter cartridges to remove particulates from the source water prior to delivery to the reverse osmosis filter membrane.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

A biological reactor system treats concentrated contaminated water with a combination of upflow and downflow bioreactors that are downstream from a reverse osmosis or other concentrator. The system may have a fail safe configuration where flush water may be introduced to the reactors in the event of a power failure or when taking the reactors offline. Many reverse osmosis systems introduce antiscalant treatments upstream so that the reverse osmosis filters do not scale. However, such treatments result in superconcentrated conditions of the antiscalants in the contaminated water processed by the bioreactors. A flushing system may deconcentrate the bioreactors to prevent the antiscalants from precipitating and fouling the bioreactors.

A desalination system (100) having an intake unit (110) providing seawater to a pre-treatment unit (120) connected to a reverse osmosis (RO) desalination unit (130) and a post treatment unit (150). The desalination system (100) is configured to operate without any external addition of chemicals to simplify logistics and regulation concerns. The units of the system are configured to prevent biofouling, scaling and corrosion by mechanical and biological means including high flow speeds, biological flocculation of colloids, and making the water entering the RO units inhospitable to bacteria and other organisms that cause biofouling, hence preventing their settlement and removing them with the brine. Recovery rate is lowered and energy is recovered to increase the energetic efficiency and minerals that are added to the product water are taken from the brine.

A desalination system (100) having an intake unit (110) providing seawater to a pre-treatment unit (120) connected to a reverse osmosis (RO) desalination unit (130) and a post treatment unit (150). The desalination system (100) is configured to operate without any external addition of chemicals to simplify logistics and regulation concerns. The units of the system are configured to prevent biofouling, scaling and corrosion by mechanical and biological means including high flow speeds, biological flocculation of colloids, and making the water entering the RO units inhospitable to bacteria and other organisms that cause biofouling, hence preventing their settlement and removing them with the brine. Recovery rate is lowered and energy is recovered to increase the energetic efficiency and minerals that are added to the product water are taken from the brine.

Provided is a method for treating a hexavalent chromium-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps of: adding catalyst particles to the aqueous solution; reducing hexavalent chromium by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

Provided is a method for treating a hexavalent chromium-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps of: adding catalyst particles to the aqueous solution; reducing hexavalent chromium by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.

The present invention provides for a method for separating starch from processing solutions containing starch containing plants or roots such as potatoes, sweet potatoes, wheat, corn, tapioca, yams, cassaya, sago, rice, pea, broad bean, horse bean, sorghum, konjac, rye, buckwheat and barley to provide commercially acceptable starch while reducing disposal of solid or liquid waste matter into landfills or water treatment facilities.

The present invention provides for a method for separating starch from processing solutions containing starch containing plants or roots such as potatoes, sweet potatoes, wheat, corn, tapioca, yams, cassaya, sago, rice, pea, broad bean, horse bean, sorghum, konjac, rye, buckwheat and barley to provide commercially acceptable starch while reducing disposal of solid or liquid waste matter into landfills or water treatment facilities.

A drinking water vending dispenser for dispensing purified water comprising a coarse mechanical filter, an RO purification unit, an ozone purification unit, a UV purification unit, an active carbon filter, a chemical base purification unit and a fine mechanical filter.