An underdrain system for a media pressure vessel has a set of removable pipe sections located between an external header and the bottom of a vessel. Septa extend upwards from the removable pipe sections into the vessel by up to 16 inches. The septa may have diameters of 6 inches or more. The header is attached to the bottoms of the removable pipe sections. Each pipe section, and its associated septum, may be removed individually. To clean the vessel. after media is removed from the vessel the pipe sections are removed sequentially while the header remains otherwise attached to the vessel. While a pipe section is removed. its associated septum is removed so that solids can be removed from the annulus between the septum and the vessel. In this way. media can be cleaned from the annuli without moving the external header or entering the vessel.

A cleaning method including an alkaline cleaning step followed by an acid cleaning step is used, for example, to treat a newly constructed ultrapure water distribution piping system (using PVDF piping system). The inherent inorganic and organic contaminants in the piping material as well as contaminants deposited (if any) during the construction phase can be removed efficiently. Therefore, the commissioning time of a newly constructed ultrapure water distribution system to meet the specified quality of contaminants can be shortened from several weeks to approximately one week.

A composition for treating a water system or membrane fluid system, such as a reverse osmosis system, to remove scale, microorganisms and biofilm, and corrosion by-products. The composition comprises chelating agents and a surfactant. The composition may be a solid dissolved by water or solvent in the system being treated or may be a pre-mixed foam or aerosol. A method for using such a treatment composition comprises contacting the treatment composition with substantially all parts of the water system and draining the treatment composition from the system before resuming normal operations. For certain systems, the method also comprises draining some existing water in the water system to remove prior treatment compositions and filling or rinsing the system with fresh water prior to adding the treatment composition.

Methods for cleaning or disinfecting water delivery systems, self-cleaning or self-disinfecting water delivery systems, and inserts for use in cleaning or disinfecting water delivery systems utilize cationic steroidal antimicrobial (CSA) molecules to kill microbes and/or break up biofilms within water delivery systems. The methods and systems involve adding CSA molecules to water to form an aqueous CSA composition and passing the aqueous CSA composition through the water delivery system, such as a water storage vessel and/or water delivery line to clean or disinfect the water delivery system. CSA molecules can be added to a water storage vessel, water delivery line, or well, such as by a solid or liquid CSA composition. A CSA-eluting composition may provide CSA molecules to water to form an aqueous CSA composition that passes through or is stored within the water delivery system. CSA molecules provided to agricultural animals in drinking water may improve animal health.

A stormwater vault and a process for servicing the stormwater vault speeds the process of cleaning a stormwater vault. The stormwater vault has a built in liquefaction system for liquefying settled debris in the vault which works together with a sloped or angled floor in the vault. The settled debris is flushed toward the inlet to a vacuum removal line inserted into the vault through an access opening for removing the settled debris from the vault.

A washing device for a water treatment apparatus is provided. The washing device includes circulation members connected to passages of the water treatment apparatus to circulate wash water through the passages of the water treatment apparatus, a circulation module connected to the circulation members for circulating the wash water through the passages of the water treatment apparatus, with the circulation members thereby washing the passages of the water treatment apparatus, a drainpipe connected to the circulation members, a passage switching unit connected to a portion where the circulation members are coupled to the drainpipe to switch passage of the wash water, and a circulation pump connected to the circulation members to selectively circulate the wash water in the connection pipes through the drainpipe or the passages of the water treatment apparatus.

A vacuum nozzle for a vacuum pump or truck, the vacuum nozzle comprising: a vacuum conduit configured to be connected to a vacuum source; a primary inlet fluidically connected to the vacuum conduit for receiving flow under suction; and a secondary inlet fluidically connected to the vacuum conduit for receiving flow under suction, the secondary inlet being positioned upstream of the primary inlet so as to allow flow to bypass the primary inlet, thereby preventing the primary inlet from sealing against a surface under suction.

This application discloses novel vacuum break devices useful in automatic vacuum flushing systems. The vacuum break devices are capable of rapidly breaking the vacuum in a storage tank of a sewer line, thus enabling efficient flushing of sediments and cleaning of the sewer system. The invention also provides automatic vacuum flushing systems comprising these novel rapid vacuum break devices and methods thereof for sewer or storage tank sediment cleaning in urban drainage systems.

A modified tank for use in microgravity environments is provided. The modified tank includes a membrane defining an interior and including an inlet leading to the interior and first and second outlets from the interior. The modified tank further includes first and second filters for the first and second outlets, respectively, and an outlet wiping pair. The outlet wiping pair includes a wiper in the interior and a wiping boss at an exterior of the membrane. The wiping boss is operably coupled to the wiper whereby operation of the wiping boss causes the wiper to wipe at least one of the first and second filters.