A wastewater treatment system comprises a fluid conveyance, one or more filtration vessels, one-way valves, and a backwash collection conduits. The filtration vessels each have a vessel inlet and a vessel outlet. Filtration media is positioned between the respective vessel inlet and the respective vessel outlet. Each respective vessel inlet communicates with the fluid conveyance. Each one-way valve is located at the inlet of the respective filtration vessel to regulate a flow of fluid from the fluid conveyance into the respective filtration vessel and to prevent the fluid from exiting the respective filtration vessels through the one-way valves. Each backwash collection conduit communicates with each filtration vessel by a drain conduit, the drain conduit having an outlet that is above a top of a fluid volume in the backwash collection conduit so as to provide an air gap.

A gasification system according to an aspect includes a scrubber device to transfer contaminant contained in a flammable gas to cleaning water and discharge the cleaning water containing the contaminant as scrubber wastewater, a heat exchange device to heat the scrubber wastewater to vaporize the contaminant contained in the scrubber wastewater; and a combustion furnace to incinerate the vaporized contaminant, wherein the heat exchange device heats the scrubber wastewater by using heat generated by the combustion furnace.

A gasification system according to an aspect includes a scrubber device to transfer contaminant contained in a flammable gas to cleaning water and discharge the cleaning water containing the contaminant as scrubber wastewater, a heat exchange device to heat the scrubber wastewater to vaporize the contaminant contained in the scrubber wastewater; and a combustion furnace to incinerate the vaporized contaminant, wherein the heat exchange device heats the scrubber wastewater by using heat generated by the combustion furnace.

Disclosed herein are systems and processes for treating a Waste Stream comprising biosolids, the Waste Stream provided at varying flow rates and solids concentrations so as to achieve an SOUR of 1.5 mg O.sub.2/g/hr or less and an ORP of at least +300 mV. The system includes a biosolids manipulation device to adjust the volume of suspended solids as a percent of the total volume of the Waste Stream to five (5) percent or less; a chemical oxidant feed device to dose the Waste Stream with an oxidant such as chlorine dioxide, ozone, or similar oxidant, and a treatment vessel associated with said chemical oxidant feed device through which said Waste Stream flows, wherein said chemical oxidant feed device and said treatment device are configured so as to achieve a dose rate between 25 and 200 parts per million of the Waste Stream and substantially complete mixing of the oxidant within 30 seconds of dose delivery in the treatment vessel.

Disclosed herein are systems and processes for treating a Waste Stream comprising biosolids, the Waste Stream provided at varying flow rates and solids concentrations so as to achieve an SOUR of 1.5 mg O.sub.2/g/hr or less and an ORP of at least +300 mV. The system includes a biosolids manipulation device to adjust the volume of suspended solids as a percent of the total volume of the Waste Stream to five (5) percent or less; a chemical oxidant feed device to dose the Waste Stream with an oxidant such as chlorine dioxide, ozone, or similar oxidant, and a treatment vessel associated with said chemical oxidant feed device through which said Waste Stream flows, wherein said chemical oxidant feed device and said treatment device are configured so as to achieve a dose rate between 25 and 200 parts per million of the Waste Stream and substantially complete mixing of the oxidant within 30 seconds of dose delivery in the treatment vessel.

A mixing aerator is disclosed that includes a housing defining a chamber having a bottom end and a top end, the housing having at least one inlet and at least one outlet; and a longitudinally extending diffuser disposed within the chamber and configured to deliver air bubbles into the chamber when the chamber is filled with liquid. The diffuser includes (a) a tubular elastomeric membrane having a plurality of perforations and, within the tubular elastomeric membrane, (b) an air pipe having a plurality of openings, the openings being larger and fewer than the perforations, and the tubular membrane having upper and lower ends that are sealed against an outer surface of the air pipe.

A system for recovering fat, oil and grease (FOG) from wastewater has multiple annular flotation zones in a concentric configuration surrounding a central column to create progressively increasing surface areas for FOG and solid particles flotation, and thereby enhance FOG recovery and removal. Each flotation zone is equipped with an independent pressurized micro air and ozone bubbles distribution system. A controlled amount of ozone can be injected into the wastewater along with recirculated effluent and micro-size air bubbles. Upon the release of pressurized air-ozone-water mixture, micro-size bubbles are generated and distributed in each flotation zone to effectively float up FOG and solid particles in the wastewater stream.

A system for recovering fat, oil and grease (FOG) from wastewater has multiple annular flotation zones in a concentric configuration surrounding a central column to create progressively increasing surface areas for FOG and solid particles flotation, and thereby enhance FOG recovery and removal. Each flotation zone is equipped with an independent pressurized micro air and ozone bubbles distribution system. A controlled amount of ozone can be injected into the wastewater along with recirculated effluent and micro-size air bubbles. Upon the release of pressurized air-ozone-water mixture, micro-size bubbles are generated and distributed in each flotation zone to effectively float up FOG and solid particles in the wastewater stream.

A system for creating an oxidation reduction potential (ORP) in water employs a plurality of ozone supply units housed in separate enclosures. The ozone supply units feed into a manifold that contains a plurality of fluid paths and has one or more ozone intake ports. The ozone intake ports are fluidically coupled to one or more ozone output ports of each ozone supply unit. The manifold includes a plurality of flow switches configured to transmit control signals to one or more controllers of each ozone supply unit in response to sensing a flow of water through the fluid paths in order to cause the ozone supply units to generate ozone. The manifold also includes a plurality of fluid mixers that are fluidically coupled to the ozone intake ports and configured to introduce the ozone generated by the ozone supply units into the water flowing through the fluid paths.

A system for creating an oxidation reduction potential (ORP) in water employs a plurality of ozone supply units housed in separate enclosures. The ozone supply units feed into a manifold that contains a plurality of fluid paths and has one or more ozone intake ports. The ozone intake ports are fluidically coupled to one or more ozone output ports of each ozone supply unit. The manifold includes a plurality of flow switches configured to transmit control signals to one or more controllers of each ozone supply unit in response to sensing a flow of water through the fluid paths in order to cause the ozone supply units to generate ozone. The manifold also includes a plurality of fluid mixers that are fluidically coupled to the ozone intake ports and configured to introduce the ozone generated by the ozone supply units into the water flowing through the fluid paths.