A method for treatment of mixed electroplating wastewater without a cyanide and a phosphorus-containing reductant without a cyanide and a phosphorus-containing reductant. A ferrous chloride solution is added into electroplating wastewater without a cyanide and a phosphorus-containing reductant. The pH of wastewater is adjusted to 10.5-12. Pollutants such as sodium cyanide and hydroxyl-containing organic amine complexants are oxidized with sodium hypochlorite. Carboxyl-containing organic acid complexants are precipitated. Hexavalent chromium is reduced to trivalent chromium to form chromium hydroxide precipitate. Precipitate is removed by filtering and wastewater is adjusted to pH 4.5-5.5. Heavy metal ions are precipitated with sodium dimethyldithiocarbamate or sodium diethyldithiocarbamate. Precipitate and heavy metal capturing agents are adsorbed with activated carbon followed by removal of precipitate. Wastewater is adjusted to pH 6-8. Aliphatic polyamine complexants are destroyed using an available biological degradation technique to reduce chemical oxygen demand.

A hybrid activated iron-biological treatment system and method for treating wastewater. The treatment system includes a combination of zero valent iron, ferrous iron, an iron oxide, and a denitrification microorganism.

A water treatment apparatus including: discharge treatment units each including a ground electrode and a discharge electrode opposing the ground electrode, and water to be treated is treated by forming a discharge between the ground electrode and the discharge electrode, and generating ozone by the discharge, and moreover causing the water to be treated to contact the discharge; a water reservoir portion that collects, in the interior of the treatment tank, the water to be treated having been subject to water treatment by one of the discharge treatment units; and an ozone supply section that supplies the ozone in the treatment tank to the water to be treated in the water reservoir portion are provided, and wherein the water to be treated passes through the plurality of discharge treatment units as a continuous flow.

An aquaculture system is provided. The aquaculture system includes a cultivation pond, a water circulation unit, a water quality detector, and a water processing module. The cultivation pond for storing the cultivation water has a recirculation inlet and recirculation outlet. The water circulation unit is in fluid communication with the cultivation pond to allow the cultivation water in the cultivation pond to circulate through the water circulation unit. The water quality detector is used to detect the quality of the water to obtain water quality information. The water processing module includes an electrolytic gas generator and a control unit to improve the quality of water. The control unit receives the water quality information and adjusts the applied voltage on the electrolytic gas generator according to the water quality information to control the gas species and a ratio of the gases generated by the electrolytic gas generator.

The object is to provide an activated sludge treatment method whereby production of excess sludge is brought substantially to zero; and a method for upgrading existing waste water treatment equipment, employing this method. The method includes a step (1) in which sludge 1 produced in a bioreactor is supplied to a waste water aeration-conditioning tank for activated sludge treatment; a step (2) in which waste water into which the sludge 1 has been mixed is subjected to aeration-conditioning to bring the oxidation-reduction potential to a positive value, and the conditioning treated waste water 1 supplied to the bioreactor; a step (3) in which released water from the bioreactor is considered to release water.

The inventive control system can be built using different measurement units and control units. What units are used for building the control system depends on the wastewater treatment plant. This kind of system structure makes it possible to construct a control system that suits for a specific wastewater treatment plant. Therefore, the invention makes it possible to build a control system for different wastewater treatment plants, in such a way that the wastewater plant operates more efficiently.

Water treatment compositions are provided that are effective for mitigating corrosion or fouling of surfaces in contact with aqueous systems. The water treatment compositions can include one or more azole compounds, one or more transition metals, and one or more dispersants, in addition to various other additives. The water treatment compositions can exclude phosphorus and still be effective. Methods for mitigating corrosion or fouling of a surface in an aqueous system are also provided.

The present application provides a waste water preconditioning system for limiting mercury concentrations in a waste water stream resulting from treatment of a flue gas. The waste water preconditioning system may include a wet flue gas desulfurization system for treating the flue gas with an aqueous alkaline slurry, a sulfite detector to determine the concentration of sulfite in the aqueous alkaline slurry, and to produce the waste water stream with a mercury concentration of less than about five micrograms per liter. The waste water preconditioning system also may include a waste water treatment system downstream of the wet flue gas desulfurization system.

A SCWO reactor fouling prevention and mitigation system that includes at least one feedstock tee which provides a feedstock to the SCWO reactor, at least one feedstock tee pressure sensor, such that each of the at least one feedstock tee has one of the at least one feedstock tee pressure sensor, at least one pressure sensor proximate a SCWO reactor inlet, and at least one pressure sensor proximate a SCWO reactor outlet. Also included is a controller which triggers a Clean In Place (CIP) procedure when there is a pressure difference between any two of the following, the SCWO reactor inlet, the at least one feedstock tee, and the SCWO reactor outlet. The CIP procedure includes washing a portion of the SCWO reactor with a fluid supplied through the at least one feedstock tee.

A recirculating aquaculture system (RAS) is disclosed, which includes a main tank, in which fish or shellfish are farmed; a first reactor fluidically connected to the main tank, wherein the first reactor is a batch reactor that operates under anoxic conditions; a second reactor fluidically connected to the main tank, wherein the second reactor is a moving bed biofilm reactor (MBBR);a feed stream fluidically connected to the main tank; and a data-driven controller operably connected to the first reactor, the second reactor, and the feed stream, wherein the data-driven controller is configured to bring and maintain the system (RAS) at a desired state.