An apparatus, buffer solutions and a method are provided for pH control of in vitro dissolution tests used to monitor the drug release rate from solid unit dosage forms which are used to predict their in vivo effects or for quality control purposes. A method of preparing a continuous condition and a clear bicarbonate ion based solution for in vitro dissolution testing of pharmaceutical products is also provided.

An enclosure device is also provided for use in the provision of pH control and stabilization to a bicarbonate based solution used in the in vitro dissolution testing of pharmaceutical products.

A bag assembly for use with a heat exchanger includes a flexible bag having of one or more sheets of polymeric material, the bag having a first end that bounds a first compartment and an opposing second end that bounds a second compartment, a support structure being disposed between the first compartment and the second compartment so that the first compartment is separated and isolated from the second compartment. A first inlet port, a first outlet port, and a first drain port are coupled with the flexible bag so as to communicate with the first compartment. A second inlet port, a second outlet port, and a second drain port are coupled with the flexible bag so as to communicate with the second compartment.

A container assembly includes a flexible bag having an interior surface bounding a chamber and an opposing exterior surface. The bag has a bottom end wall that includes a first sparger and a second sparger. The first sparger and the second sparger each have a flexible first sheet overlying a flexible second sheet, the first sheet and the second sheet being secured together so as to form a sparging area bounded between the first sheet and the second sheet, at least a portion of the first sheet overlying the sparging area being gas permeable so that gas can pass from the sparging area, through the first sheet, and into the chamber.

A system and method for aerating and mixing wastewater that includes fine bubble diffusers located at least partially below a large bubble mixer. At least a portion of the gas discharged from the fine bubble diffusers is captured by the large bubble mixer and is reused by the large bubble mixer to form and release intermittent large bubbles. Prior to being captured by the large bubble mixer, the gas discharged by the fine bubble diffusers can aerate the wastewater. The large bubble mixer includes an accumulator that, upon becoming filled with gas, generates and releases a large bubble. Upon discharge from the large bubble mixer, the large bubbles generated therein may separate into a plurality of coarse bubbles for providing additional oxygen transfer and mixing of the wastewater. The system may include supply lines for supplying gas only to the fine bubble diffuser.

A treatment plant and method for controlling a treatment plant suitable for treatment of wastewater. The treatment plant includes a circulation channel housing liquid, a submersible flow generating machine arranged in the circulation channel and generating a liquid flow along the circulation channel, and a control unit that is operatively connected to the flow generating machine. The flow generating machine is driven in operation by the control unit. The method includes the steps of: driving the flow generating machine at a nominal speed, decreasing the rotational speed of the flow generating machine from the set nominal speed, detecting the rotational speed at which the torque of the flow generating machine is equal to a predetermined threshold, and determining the flow velocity of the liquid at the flow generating machine based on a predetermined relationship between the rotational speed of the flow generating machine and the flow velocity of the liquid.

Embodiments disclosed herein provide systems and methods for water aeration in a tank or other body of water that a specialized coupling assembly and flexible hose connectors rather than the commonly used rigid connector elements. The coupling assembly and flexible hose connectors utilized in the aeration grid system provide a more cost effective and flexible system that allows almost limitless configurations of the diffuser elements, depending on the intended application. Further, the coupling assembly and flexible hose connectors enable use with a wide variety of air supply pipe diameters without the necessity of providing a fitting or adapter for each pipe opening. The capability of the aeration system to be readily adapted to different sizes of treatment tanks or ponds, for example, allows the installation and use of a more flexible, prefabricated, or modular, and ultimately more efficient aeration system.

An elongate diffuser (10) comprises a diffuser body (30), and a membrane (20) attached so that introduction of gas at a working pressure into the diffuser displaces part of the membrane (20) from contact with the diffuser body (10) providing an elongate sealed compartment (50) between the membrane (20) and a surface (32) of the diffuser body (30). The gas can pass from the compartment (50) through the membrane (20) for aeration of fluid in which the diffuser (10) is immersed. The diffuser body surface (32) which bounds the compartment (50) is recessed away from the membrane (20) in use, to contribute to the lateral cross sectional area of the compartment (50) and facilitate distribution of gas along the diffuser by the compartment (50). An automatic purge valve for purging water from a gas feed pipe of a diffuser is also disclosed.

A device for bubbling a gas into a liquid is disclosed. The device comprises a first bubbling apparatus nested inside a second bubbling apparatus. The first bubbling apparatus comprises a gas inlet for receiving the gas and a plurality of first openings for releasing the gas. The second bubbling apparatus at least partially encloses the plurality of first openings of the first bubbling apparatus. The second bubbling apparatus receives the gas from the plurality of first openings. The second bubbling apparatus comprises a plurality of second openings for bubbling the gas into the liquid.

A method for filtering a gas includes passing a gas into a compartment of a casing that includes a polymeric film, the casing having: a first sleeve having a first outlet opening, a first filter being at least partially disposed within the first sleeve so that gas passing through the first sleeve must pass through the first filter; and a second sleeve having an second outlet opening, a second filter being at least partially disposed within the second sleeve so that gas passing through the second sleeve must pass through the second filter, the second sleeve being closed so that the gas passing into the compartment of the casing passes through the first sleeve and the first filter and directly contacts at least a portion of the first sleeve comprised of the polymeric film but does not pass through the second sleeve. Opening the second sleeve when a predetermined condition is met so that the gas passes through the second sleeve and the second filter.

A fine bubble generating apparatus has a storage tank, a liquid feeding unit suctioning and feeding liquid stored in the storage tank, a gas discharge unit discharging gas into the liquid which is being fed by the liquid feeding unit, and a storage tank. The gas discharge unit includes a gas discharge member with pores having pore diameters of 1.5 m or less, and a base member having a groove formed in a surface contacting the gas discharge surface of the gas discharge member. The liquid feeding unit moves the liquid along the gas discharge surface of the gas discharge member by causing the liquid to flow in a flow channel enclosed by the gas discharge surface of the gas discharge member and the groove of the base member such that a velocity relative to the gas discharge member is not less than 1 msec.