A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

The present technology relates to control systems for use with fluid treatment systems. In one embodiment, for example, a fluid treatment system includes a vessel configured to receive a fluid having one or more constituents and to separate one or more constituents from the fluid. The system can also include a tube extending along at least a portion of the vessel and a sensor. The tube can be in fluid communication with a pressurized air source, and the sensor can be configured to obtain a measurement of an operating parameter. The system can also include a controller in communication with the sensor and pressurized air source. The controller can execute one or more algorithms to determine a filter parameter based on the measurement of the operating parameter, compare the filter parameter to a threshold, and, based on the comparison, activate or deactivate the pressurized air source.

Systems and methods for treating wastewater are disclosed. Zero valent iron media may be used in a moving packed bed reactor. A media recovery system may return media to the reactor.

An upflow continuous backwash deep bed sand filter (UCBF) having a recycle line for returning carbonaceous denitrifying bacteria attached to biomass to the influent of the UCBF. The recycle line returns the biomass to the treatment process at a location upstream of the upflow continuous backwash filter. Further, a liquid level control unit is provided that reduces fluctuations and significant drop in the liquid level upstream of the upflow continuous backwash filter, thereby avoiding or minimizing flow turbulences, air induction, and undesirable wastewater aeration resulting in the need to dose excessive carbon source to remove dissolved oxygen in the aerated wastewater.

The invention provides an apparatus and method for purification of a fluid, the apparatus comprising: a vessel (1) for receiving, in operation, a filter bed (2) with granular filter material; a transport system (8) configured to, during operation, transport filter material from a cavity (5) underneath the filter bed (2) to a location (17) above the filter bed; a fluid inlet (14) for introducing fluid to be purified into the apparatus; a mixing section (3) adapted to, in operation, provide a mixture of fluid from the fluid inlet and granular filter material from the filter bed in a part of the vessel beneath the mixing section; and a plurality of gas lift injectors (4), wherein each gas lift injector (4) is configured to, in operation, transport the mixture of fluid from the fluid inlet (14) and granular filter material from the filter bed (2) to the cavity (5).

Exemplary systems and methods relating to washboxes are described.

Exemplary systems and methods relating to washboxes are described.

Exemplary systems and methods relating to washboxes are described.

The present technology relates to control systems for use with fluid treatment systems. In one embodiment, for example, a fluid treatment system includes a vessel configured to receive a fluid having one or more constituents and to separate one or more constituents from the fluid. The system can also include a tube extending along at least a portion of the vessel and a sensor. The tube can be in fluid communication with a pressurized air source, and the sensor can be configured to obtain a measurement of an operating parameter. The system can also include a controller in communication with the sensor and pressurized air source. The controller can execute one or more algorithms to determine a filter parameter based on the measurement of the operating parameter, compare the filter parameter to a threshold, and, based on the comparison, activate or deactivate the pressurized air source.

Provided is a continuous circulation sand filter including a filtering barrel filled with a sand filtering layer, an inflow tube for introducing raw water into the filtering barrel, a treated water discharge part for discharging treated water purified by passing the raw water through the sand filtering layer from a lower end of the sand filtering layer to an upper end thereof, an air lift tube for transferring contaminated sand, located in the lower end of the sand filtering layer, from a lower part of the filtering barrel to an upper part thereof, a transfer water discharge filter contacting the air lift tube to discharge transfer water moved upward together with sand through the air lift tube and trap the sand and a foreign substance, a descent guide tube downwardly moving the sand and the foreign substance moved to the upper part of the filtering barrel through the air lift tube, and a foreign substance separation tube suctioning the downwardly moving foreign substance to remove the foreign substance from the downwardly moving sand, and discharging the foreign substance.