With respect to atmospheric steam generating humidifiers, the present disclosure resolves the problem of end-users not adjusting the drain interval of the humidifier by using an electronic controller to automatically choose an appropriate drain interval without requiring any user input. The electronic controller accomplishes this by receiving input data from a sensor that measures a water quality parameter, automatically determining a drain interval based on the received data, and sending an output control signal to a drain water control valve to execute a drain event in accordance with the drain interval. In some examples, the electronic controller utilizes a look-up table correlating the water quality parameter to a total dissolved solids or cycles of concentration value.

A waste stream is treated by anaerobic digestion. A process is described involves a step of separating solids from digestate, and returning separated solids to a digester. Optionally, there may be a step of solids separation in which larger solids are removed from the digester. A process and apparatus are described for treating waste sludge from a wastewater treatment plant in an anaerobic digester. Feed sludge is thickened or solids are separated from digestate and returned to the digester. Additional co-digestion waste may be added to the digester. The process and apparatus may be used in a retrofit of an existing wastewater treatment plant.

Provided herein are methods of reducing microbial concentrations in water with a peracid disinfectant. The method can include the steps of measuring the quality of the water in real-time and dosing the water with a first dose of a peracid disinfectant; measuring the peracid disinfectant demand; and adding one or more subsequent doses of the peracid disinfectant. The subsequent peracid disinfectant dose can be controlled by a processor-based controller based on peracid disinfectant demand.

An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.

Disclosed herein is a water treatment system for connection to a water treatment plant (e.g. a dissolved air flotation device). The plant may have an inlet for the receipt of feed water (e.g. waste water) and an outlet for the discharge of treated water. The treatment system may comprise a first sensor disposed such that it is in fluidity communication with the feed water, and a second sensor disposed such that it is in fluidity communication with the treated water. The first and second sensors may be configured to sense parameters of the feed and treated water. The system may further comprise a first applicator (e.g. a pump) that is configured to discharge a treatment source (e.g. a chemical source) to the plant to treat the feed water. The disclosed system may be used to treat waste water (e.g. the treatment of effluent from oil refineries, petrochemical and chemical plants, natural gas processing plants, paper mills and general water treatment). The system has analogous applications in other processing methods that also use DAF, or very similar, systems, such as the processing of mineral ores and other such solid extraction processing methods.

A desalination system includes a water tank, a water-repellent particle layer located at a lower portion of the tank and composed of water-repellent particles, and a devolatilizing layer located below the water-repellent particle layer. Liquid is introduced to the tank, the introduced liquid is heated to be evaporated into water vapor, and the water vapor passes through the water-repellent particle layer and is liquefied at the devolatilizing layer, so that fresh water is obtained from the liquid. The desalination system further includes a liquid level controller for determining a level of the liquid introduced to the tank in accordance with information on relationship between information corresponding to an amount of the liquid introduced to the tank and a surface level of the liquid in the tank, and an introduced amount controller for adjusting the amount of the liquid introduced to the tank in accordance with the determined liquid surface level.

The present invention relates to apparatus, methods, and applications for treating wastewater, and more particularly to biological processes for removing pollutants from wastewater. This invention further relates to apparatus and methods for growing microbes on-site at a wastewater treatment facility, and for economically inoculating sufficient microbes to solve various treatment problems rapidly.

Disclosed is a facility for treating waste water of municipal or industrial origin, in particular a facility for primary treatment of the water, including a biological contact tank equipped with biological rotating discs, which is connected upstream of a ballasted-floc physiochemical decanter, the decanter being at least made up of a coagulation zone, a flocculation zone, a lamellar decanting zone and a thickening zone and an external circuit allowing the recirculation of the sludge thickened in the thickening zone to the flocculation zone and the biological contact tank.

A wastewater treatment system is provided having a pretreatment tank which receives wastewater from a wastewater source, and an aeration tank which is in fluid communication with the pretreatment tank. A recirculation pump is carried in the aeration tank and returns wastewater from the aeration tank to the pretreatment tank. The recirculation pump returns the wastewater according to a recirculation ratio R:I where R is the volumetric flow rate of wastewater through the recirculation pump and I is average volumetric flow rate of wastewater entering the pretreatment tank. A control panel cycles the recirculation pump on and off according to the recirculation ratio.

The present invention relates to a water treatment method including: a filtration step of feeding water to be treated to a membrane filtration device having loaded therein a porous separation membrane and performing filtration treatment to obtain filtrate; a discharging step of discharging the water to be treated in the membrane filtration device, which has been separated and concentrated by the porous separation membrane; and a cleaning step of cleaning the porous separation membrane by at least one treatment of physical cleaning and chemical cleaning, in which a cycle including a combination of the filtration step, the discharging step and the cleaning step is repeated multiple times, thereby obtaining filtrate. In each cycle, the filtration step and the discharging step are repeated multiple times, and the cleaning step is then carried out.