An etching solution recycling system for a wafer etching apparatus is provided. The etching solution recycling system includes a settling tank, a seed provider, and a fluid control unit. The settling tank is connected to an etching tank of the wafer etching apparatus and configured to receive an etching solution from the etching tank. The seed provider is configured to provide at least one seed crystal into the settling tank to reduce the silicate concentration in the etching solution in the settling tank. The fluid control unit is configured to deliver the etching solution in the settling tank back into the etching tank.

A frac sand separator system includes a sand separator having an inlet fluidly connected to a well for receiving a fracking return mixture from the well. The sand separator is configured to separate water of the fracking return mixture from particulate matter of the fracking return mixture. The sand separator includes an outlet. The frac sand separator system includes a collection container fluidly connected to the outlet of the sand separator for receiving the particulate matter from the sand separator. At least one outlet valve is fluidly connected between the outlet of the sand separator and the collection container. The frac sand separator system includes a computing device operatively connected to the at least one outlet valve. The computing device includes a processor configured to automatically open the at least one outlet valve such that the particulate matter is released from the sand separator into the collection container.

This sampling device for a coagulation treatment device (1) comprises at least: a sealed-type coagulation reaction tank to which is introduced water to be treated to which a flocculant has been added; and a solid-liquid separation tank to which is introduced the water to be treated that has been drawn from the coagulation reaction tank, the sampling device comprising a sampling tank, a coagulation sensor installed inside the sampling tank, and a water sending pipe (43) which sends, from the coagulation reaction tank of the coagulation treatment device to the sampling tank, a part of the water to be treated inside the coagulation reaction tank.

This sampling device for a coagulation treatment device (1) comprises at least: a sealed-type coagulation reaction tank to which is introduced water to be treated to which a flocculant has been added; and a solid-liquid separation tank to which is introduced the water to be treated that has been drawn from the coagulation reaction tank, the sampling device comprising a sampling tank, a coagulation sensor installed inside the sampling tank, and a water sending pipe (43) which sends, from the coagulation reaction tank of the coagulation treatment device to the sampling tank, a part of the water to be treated inside the coagulation reaction tank.

An arrangement and a method for controlling a dewatering process including measuring values representing operating parameters of the gravitational sedimentation device and using the values as input values for a predictive multivariable model for predicting an operating state of the gravitational sedimentation device. The disclosure further relates to obtaining reference values for the operating parameters, determining at least one predicted output for an operating parameter of the gravitational sedimentation device, and comparing the predicted output to at the reference values to determine control values that will affect changes in operation of the gravitational sedimentation device.

An arrangement and a method for controlling a dewatering process including measuring values representing operating parameters of the gravitational sedimentation device and using the values as input values for a predictive multivariable model for predicting an operating state of the gravitational sedimentation device. The disclosure further relates to obtaining reference values for the operating parameters, determining at least one predicted output for an operating parameter of the gravitational sedimentation device, and comparing the predicted output to at the reference values to determine control values that will affect changes in operation of the gravitational sedimentation device.

A method is disclosed for monitoring and controlling treatment of a waste water stream. The method includes measuring UV absorbance of a waste water influent and/or waste water effluent, measuring turbidity of the waste water influent and/or waste water effluent, and determining the concentration of dissolved organics in the waste water influent and/or waste water effluent based on the measured UV absorbance. The method includes controlling the dosing of at least one coagulant to the waste water influent based on the measured UV absorbance and/or the determined concentration of the dissolved organics, and optionally based on the measured turbidity, and optionally controlling the dosing of at least one flocculant to the waste water influent based on the measured turbidity.

A system for separating solids from a fluid includes a containment vessel having a V-shaped tank in fluid communication with an agitated overflow tank. Baffles within the V-shaped tank provide a series of zones where the fluid is deposited for processing. A shaftless auger at the bottom of the V-shaped tank transfers solids to an area where they are pumped to a first hydrocyclone assembly associated with a first shaker. Overflow from the hydrocyclone assembly and underflow from the first shaker is further processed by a second hydrocyclone assembly associated with a second shaker. Overflow from the second hydrocyclone assembly and underflow from the second shaker are deposited into overflow tank which contains the cleaned fluid.

A thickener/clarifier system includes a thickener/clarifier and one or more sensors measuring respective process or operating parameters of the thickener/clarifier(s) during operation thereof. The sensors are operatively coupled via hard-wired connections and possibly via 4-20 mA converters to one or more wireless transmitters. At least one wireless receiver receives the wireless signal(s) from the transmitter(s). At least one display is hard-wire coupled to the receiver(s) for displaying a magnitude of each process or operating parameter measured.

An apparatus for reducing the water content of waste water sludge includes a column for receiving waste water sludge, an outlet at a lower end of the column, a first closure for closing the outlet of the column, a controller for controlling the opening and closing of the closure. The controller is adapted to open and close the first closure to periodically discharge amounts of settled fines from the lower end of the column. A water outlet is adapted to receive water overflowing from an upper end of the column.