Abstract: A method and apparatus provide pulsed fluid treatment at a plurality of distinct points utilizing pulsed magnetic energy concentrated in a plurality of distinct areas along a fluid flow path. The instant invention prevents the formation and accumulation of contaminants within conduits and on equipment utilized in the transportation, delivery and processing of fluid columns. It may also be utilized to accelerate the separation of oil and water and increase the efficiency of oil/water separation equipment.

Abstract: In order to rapidly remove an organic acid dissolved in contaminated water, a coagulant capable of forming a floc with the organic acid in the contaminated water is configured to include an iron oxide bearing an inorganic acid on surface thereof, and an aqueous solution of an acidic-group-containing polymer. Upon removal of the organic acid as a floc from the contaminated water using the coagulant, the iron oxide bearing an inorganic acid on surface is initially added to the contaminated water, and then the aqueous solution of the acidic-group-containing polymer is added to precipitate a floc, and the floc is magnetically separated.

Abstract: The present invention relates to a method for purification of produced water and to a system for carrying out the inventive method. Further, the invention relates to a purified produced water product obtainable according to the invention. A unique sequence of unit operations including the addition of dissolved calcium hydroxide and the subsequent precipitation thereof enable a particularly efficient removal of contaminating substances from produced water from the petrochemical industry.

Abstract: An integrated unit operations for the treatment of a waste stream, such as spent caustic, is provided in a single vertical vessel having at least three separate zones: a mixing, a settling, and a mass transfer zone.

Abstract: Disclosed is an improved water treatment apparatus. The treatment apparatus is pressurized and operates on a continuous flow of fluids which are subjected to hydrodynamic waves, acoustic ultrasonic waves in combination with injected ozone. The treatment tank includes a tangential inlet that induces a rotating flow into the tank thereby increasing the mixing of the ozone within the effluent. The ozonated fluid is further electro chemically treated with DC current. The treatment tank provides a cost efficient and environmentally friendly process and apparatus for cleaning and recycling fluids as contaminated as frac water, used to stimulate gas production from shale formations, as well as other types of fluids having various levels of contaminants such as aerobic and anaerobic bacteria and suspended solids.

Abstract: Bubble generator devices to produce a fluid stream comprising bubbles are described. Apparatuses that include any of the described bubble generator devices to treat waste and/or frac-water are also described.

Abstract: A combination micro-filtration halogen apparatus safely delivers drinking water by metering doses of concentrated aqueous iodine into a filtered water supply contained within a chamber. Untreated water is poured into the water filter column that allows for gravity to force the water through filters and the filtered or purified water depending on the filters is stored within a lower chamber of the column for disinfection. An aqueous iodine roller metering system controls the amount of iodine dispensed from an aqueous iodine container to the filter column. Turning the roller mechanism accurately meters a selected dose of concentrated aqueous iodine from the iodine container into the lower chamber of the water column. The active residual iodine disinfectant kills microbes in the filtered or purified water making it safe to consume and prevents recontamination. The iodinated drinking water also provides for essential daily human micronutrient requirements.

Abstract: The invention relates to a device for cleaning fluid media containing particulate matter, particularly from livestock husbandry, by means of ozonization in a closed ozonization container (11) and subsequent separation of the particulate matter portions. A vertically extending hollow cylindrical fixture (17) is disposed in the closed ozonization container (11). The fixture (17) is operatively connected to a rotating agitator shaft (16), wherein agitation means (18, 19) are associated with the agitator shaft (16), and the fixture (17) is equipped with supply lines (22, 23) by means of which ozone can be fed.

Abstract: The present invention relates to a process for the treatment of liquid effluents laden with hydrocarbons, which comprises: feeding the effluents into a treatment tank; supplying the treatment tank with a reversible sorbent having a defined particle size; mixing the effluents with the reversible sorbent in the treatment tank in order to load said reversible sorbent with the hydrocarbons in the effluents; removing the hydrocarbon-laden reversible sorbent from the top of the treatment tank; extracting the treated effluents from the bottom of the treatment tank; and separating the hydrocarbons from the laden reversible sorbent from the treatment tank.

Abstract: The wastewater treatment system includes a hollow, elongate, horizontally disposed, cylindrical body made from plastic is adapted for water storage and treatment. The cylindrical body includes reinforcement ribs formed by a helically wound steel band embedded in the plastic and extending between opposite open ends of the elongate cylindrical body. A voltage source selectively energizes the steel band. A pair of bulkhead members respectively extends across and covers opposite ends of the cylindrical body. A fluid-tight wall is mounted in the cylindrical body, the first bulkhead member, the fluid-tight wall and the cylindrical body forming a fluid-tight tank defining a liquid storage chamber. The second bulkhead member and the fluid-tight wall define a dry liquid treatment equipment chamber. An inlet pipe extends into the tank for admitting the pretreatment liquid into the tank. An outlet pipe extends from the tank and discharges the treated liquid from the tank.

Abstract: An apparatus for a programmable self sanitizing water dispenser apparatus with a digital controller as well as a programmable method for generating ozone for cleaning the reservoir and the water contained within it. The apparatus includes an anti-spill receiver that houses the controller and that can contain a ozone generator.

Abstract: Reactive beads interact with a fluid to be treated in a treatment chamber that retains the beads in the chamber and provides a geometry which promotes the fluid flow agitation of the beads to enhance the treatment.

Abstract: Utilizing mobile walls, a transportable (or stationary) low cost, low carbon footprint process and apparatus with a granular filter media dry cell (for filter or bed) for dewatering particulate solids from liquid. The mobile wall structures can be made of a rigid structure constructed of new or preferred salvaged materials, assembled, with watertight joints, used, disassembled and stored for redeployment. The walls are set in a keyway utilizing whatever soil composition is available. The walls can be used in the previous Deskins filters as old wall replacement or new wall construction. The invention utilizes a generator that is not dependent upon site or local electricity thus can be operated in any location. All parts can be engineered, fabricated according to the design of the Quick-Dry Filter Dewatering Mobile Process and Apparatus, packed in shipping containers and be readily available for any immediate need.

Abstract: A blood storage container suitable for quick and efficient production of a large amount of serum while ensuring high safety, and a method of separating blood and a regenerative medical process using the same are provided. A blood component separation storage apparatus is provided for separating a plurality of blood components of blood so as to be stored therein. The blood component separation storage apparatus includes a blood reservoir for holding the blood and a component storage part connected to the blood reservoir aseptically and in an air-tight manner. The blood reservoir contains an anticoagulant which suppresses coagulation of the blood. The blood reservoir has a serum producing function to remove coagulation factors from the blood to an extent enabling use in practical applications as a serum, and the component storage part stores each blood component generated by separation of the blood in the blood reservoir.

Abstract: In a nanofiltration system for removing sulfate impurity from an aqueous brine stream and for recovering the brine, introducing a dilution stream upstream of the feed stream inlet of a nanofiltration module in the system dilutes the feed stream. This increases the amount of brine salt and water obtained in the permeate stream without substantially diluting the concentration of sulfate in the pass stream and hence results in enhanced recovery of brine while efficiently removing sulfate impurity. The system and process is especially suitable for recovering brine and removing sulfate impurity from a brine stream in a brine electrolysis plant. In a conventional system, the heat exchanger typically used to cool the feed stream can be omitted if the dilution stream is provided at a temperature suitably lower than that of the feed stream.

Abstract: Methods, systems, and compositions for clarifying drilling mud are provided. A method of clarifying drilling mud includes at least: mixing a hydrophilic solution and an effluent; the effluent comprising an oil lubricant and solid particles; binding the solid particles to the hydrophilic solution; separating the oil lubricant from the solid particles; and recovering the oil lubricant. A system includes at least: a mixing tank for mixing a hydrophilic solution and an effluent, the effluent comprising an oil lubricant and solid particles, and creating a mixture; and a centrifuge connected to the mixing tank, the centrifuge being capable of receiving the mixture and separating the hydrophilic solution, the solid particles, and the oil lubricant, and discharging the separated oil lubricant. A composition for clarifying drilling mud includes at least: a homogeneous mix of at least one hydrophilic substance.

Abstract: A wastewater treatment system is provided having a reactor, first and second bio media and an aeration system. The first bio medium is located proximate an inlet end of the reactor and extends vertically between a top water level and the reactor's floor. The second bio medium is located proximate an outlet end of the reactor and extends vertically between a bottom water level and the reactor's floor. The media are adapted for retaining solids within the reactor as clarified water is withdrawn after treatment. The first bio media is further adapted to act as a baffle thereby causing wastewater to flow generally uniformly into a primary reactor zone. The aeration system includes a plurality of diffusers, some of which may be located adjacent or underneath the bio media and are adapted for promoting the shaking the bio media when activated in order dislodge excessive biomass therefrom.

Abstract: Modular systems for extracting hydrocarbons from subterranean volumes and associated methods are generally described.

Abstract: In one embodiment, a method includes gasifying a fuel source using a first oxygen stream supplied from an air separation unit (ASU), discharging a gasifier blowdown from a gasification and scrubbing system configured to gasify the fuel source, generating a grey water from the gasifier blowdown, and biologically treating the grey water in a reactor using a second oxygen stream supplied by the ASU.

Abstract: A solid dissolver system for the treatment of waste material in a waste water collection system. The solid dissolver system includes a housing. The housing includes a cover and a platform portion for receiving the cover. A cartridge containing agents for the treatment of waste material is disposed within the cover, the cover substantially surrounding and enveloping the cartridge, the cover including an opening. A water inlet is provided into the housing, the water inlet terminating at a spray means disposed proximate to or inside the cover opening, the spray means being capable of directing water at an exposed surface of the cartridge, the platform portion being capable of collecting any effluent from the water directed at the exposed surface of the cartridge by the spray means. A water outlet for channeling the effluent into a waste water collection system is included in the platform portion.

Abstract: A system and process for frac water sonic treatment are disclosed. The process involve novel treatment in which frac water is cleaned to potable water standards using a proprietary sonic reactor. Treatment enable neutralization of toxins and may remove bacteria, oil, and/or heavy metals when contained in frac water. The novel treatment system includes portable and scalable equipment of design that may allow optimal economic operation to a plurality of industrial process using clean water.

Abstract: According to one embodiment, a copper recovery apparatus includes a precipitation tank configured to precipitate copper hydroxide grains in water, a filter aid supplier, a mixing tank configured to mix the filter aid with a water to produce a suspension, a separator provided with a filter, a line configured to supply the suspension to the separator, thereby forming a precoat layer formed of the filter aid on the filter, a separation tank configured to receive the detached matter of the precoat layer discharged together with the detaching water from the separator to magnetically separate copper hydroxide grains and filter aid, a line configure to discharge and recover the detaching water from the separation tank, and a line configured to return the separated filter aid to the filter aid supplier from the separation tank.

Abstract: A water treatment system, for example for treating grey water from domestic appliances comprises a water treatment device containing a filter media through which the water passes to remove particulates and bio-matter. The device has a lid provided with a spraying device. The spraying device may, for example, receive treated water along a line, possibly with the addition of an anti-foaming agent. Operating of the spraying device thus serves to collapse any foam generated within the water treatment device. Filter media can be cleaned periodically in a cyclone, after being drawn up through a pipe by means of a jet pump, receiving treated water along a line. Treated water is stored in a storage tank for subsequent use.

Abstract: The present invention discloses device that can generate a strong vortex in the vortex chamber which significantly enhances rate of reactions and effectiveness of waste water treatment. The present invention disclose vortex diodes with or without inserts/stabilizers as continuous flow reactors to induce cavitation to generate radicals which reduces Chemical Oxygen Demand (COD), ammoniacal nitrogen and color of waste water effectively in effluent treatments.

Abstract: The present invention relates to a system or method for the remediation of wastewater with a treatment media in tandem with an electrocoagulation system. The system and method also include cleaning elements for cleaning distribution lines within the system and for cleaning the electrocoagulation system.

Abstract: A dialysis system includes a filtration system capable of filtering a water stream, a water purification system capable of purifying said water stream in a non-batch process, a mixing system capable of producing a stream of dialysate from mixing one or more dialysate components with the water stream in a non-batch process, and a dialyzer system. The dialyzer may be a microfluidic dialyzer capable of being fluidly coupled to the stream of dialysate and a blood stream.

Abstract: The invention is directed to systems and methods of biological and chemical treatment of wastewater comprising organic nitrogen compounds. Systems may include: an aerobic reactor, a first separation module for separating liquid and solid components of the wastewater; an oxidation module for removing organic materials from the wastewater; and a post-anoxic reactor for denitrifying at least a portion of the wastewater. Systems may include a second separation module and various feedback recycle lines between the components. Methods may include: degrading by the aerobic reactor more than 95% of organic compounds to ammonia, oxidizing by the oxidation module at least a portion of the ammonia to nitrates, and degrading by the post-anoxic reactor at least a portion of the nitrates to nitrogen gas and water. Systems and methods may reduce total organic carbon of the wastewater by more than 90%, and total nitrogen of the wastewater by more than 90%.

Abstract: A countercurrent tank type supercritical water reactor with a sacrificial lining, comprising a cylinder body and a catalyst tank arranged inside, the upper part of the cylinder body is connected with a top cover, and the lower part of the cylinder body is connected with a spherical head, the inner side of the cylinder body, the inner side of the spherical head and the inner side of the top cover constitute the inner wall of the reactor, wherein the inner wall of the reactor is provided with a high temperature resistance and thermal insulation coating layer, the inner wall of the high temperature resistance and thermal insulation coating layer is provided with a sealing coating layer, and the inner wall of the sealing coating layer is provided with the sacrificial lining. The reactor is of a countercurrent tank type, which can prevent the reactor blockage caused by salt deposition.

Abstract: A method and apparatus provide fluid treatment at a plurality of distinct points utilizing magnetic energy concentrated in a plurality of distinct areas along a fluid flow path and at least one region of pulsed fluid treatment within a fluid treatment chamber. The instant invention prevents the formation and accumulation of contaminants within conduits and on equipment utilized in the transportation, delivery and processing of fluid columns. It may also be utilized to accelerate the separation of oil and water and increase the efficiency of oil/water separation equipment.

Abstract: The invention relates to a device and a method for the separation of solids from a biowaste slurry before heat treatment, and for heat treatment of the separated solids. The device comprises a chamber with a main inlet port for feeding slurry, and outlet ports. A unit for separating solids is adapted to an outlet port so, that liquid leaving the chamber has passed through the separation unit. A second outlet port is provided directly from the chamber to allow removal, following sterilization, of solids collected in the chamber. The sterilization is secured by temperature monitoring at representative locations.

Abstract: A method of treating wastewater containing peroxide and ammonia includes performing a first stage peroxide pretreatment of the wastewater with a catalyst, and performing a second stage ammonia separation of the peroxide treated wastewater by a distillation process, thereby producing a concentrated ammonium hydroxide end product that is separated from the wastewater.

Abstract: The invention is a method for treating fluid in a main fluid reservoir, e.g., a pool, spa, or water tank, etc., using ozonated air. A fluid filter is placed in an auxiliary fluid reservoir located in or next to the main fluid reservoir. An ozone generator pumps a combination of ozone and air into the auxiliary reservoir. Fluid in the auxiliary reservoir passes through a filter and back into the main reservoir without the use of any fluid pump. More specifically, a vertical lift tube is placed beneath the auxiliary fluid reservoir so that the open top of the lift tube is within the auxiliary reservoir. Fluid from the main reservoir is fed to the bottom of the lift tube. Ozone and air from the ozone generator is also piped into the lift tube near its bottom. The fluid flows through the filter due to the effect of ozone and air bubbles released by a diffuser at the bottom of the lift tube.

Abstract: Described herein are methods of separating a first soluble salt from water that contains the first soluble salt and a second soluble salt, by (a) adding a composition to a water product containing a first soluble salt and a second soluble salt, the composition comprising seed crystals composed substantially of a target insoluble salt to be formed from the first soluble salt; and (b) collecting the target insoluble salt. These methods may be used, for example, to separate strontium from water that includes at least one soluble strontium salt and a second soluble salt (such as one soluble calcium salt).

Abstract: Described herein are devices for providing drinking fluid from feed sources comprising: a first reservoir, a filter for mechanically removing particles and a second reservoir for receipt of the processed feed fluid. A continually disinfecting element is disposed in either or both reservoirs to remove additional materials from the fluid. Drinking fluid is provided in a portable device. Optional light sources are provided to interact with the disinfecting elements and/or provide an indication of the contained suitability of such disinfecting elements. A method for creating drinking fluid from a feed source is also disclosed.

Abstract: The invention relates to a device and a method for cleaning sample material, in particular nucleic acids. The cleaning process takes place by means of centrifugal microfluidics and the invention provides a simple compact construction and a simple procedure. If necessary, the sample material is easily mixed with a solvent buffer and proteases in the device. The cleaned sample material is in particular transferred directly to a container. Separate containers for the removal of excess liquid are not required.

Abstract: A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The water is treated by utilizing a free radical scavenging system and a free radical removal system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The free radical removal system can comprise use of a reducing agent. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized to regulate addition of the precursor compound, the intensity of the actinic radiation, and addition of the reducing agent to the water.

Abstract: The described implementations relate to water denitrification. One method obtains nitrate levels in influent and effluent of a moving bed media filter and determines carbon levels in the effluent. The method also doses carbon feedstock into the influent based on both the nitrate levels and the carbon levels.

Abstract: A device for sewage treatment, including: a reactor and a magnetic field generator. The reactor includes a stirrer, an aerator, an activated sludge zone, an upper end including a water inlet, a side wall including a water outlet, and a bottom including a sludge outlet. The magnetic field includes magnets and iron plates. The activated sludge zone is disposed inside the reactor. The stirrer and the aerator are disposed within the activated sludge zone. The aerator is arranged beneath the stirrer. The magnetic field generator is disposed outside the reactor. The magnets and the iron plates are symmetrically disposed on two sides of the reactor, respectively, and each of the magnets is disposed on the inner side of the corresponding iron plate. The magnets disposed on both sides of the reactor produce magnetic fields having the same direction.

Abstract: Embodiments of the present invention provide a filtration system that can be used to filter debris-laden water and to systems for cleaning the filtration system using a vacuum flush system to create a backwash flow through the filter of the filtration system. The filtration system described finds particular use on-board passenger transport vehicles that have a vacuum waste system, such as aircraft. The filtration system provides the ability to collect, treat, and reuse liquid resources in an environment with a vacuum waste system.

Abstract: A system and method for processing impure water is achieved by using ozone for the separation and removal of certain contaminants and for further purification of the water. According to one embodiment, a gas comprised of ozone and air is injected into the impure water. The gas is converted to bubbles which are used as a flotation reagent while the ozone portion of the gas provides for the disinfection and deodorization of the liquid. The impure water is constantly supplied into an upper portion of a working volume or column of fluid contained within a processing unit. At the same time the gas is supplied into the bottom part of the same fluid column through one or more diffusers. Due to their porosity the diffusers generate the bubbles of this ozone-based gas so that each bubble has a predetermined size.

Abstract: An apparatus for treating water stored in a reservoir to remove contaminants has a feed line for receiving water and a by-pass valve that controls the flow of water through the feed line. A venturi valve responds to the rate of flow of water through a flow line by creating a vacuum in a supply line from an ozone generator, the extent of the vacuum created being dependent on the rate of flow, to add ozone at a controlled rate to the water to be treated. A sensor probe measures the oxidation reduction potential of the water, to supply hydrogen peroxide to the water at a controlled rate dependent on the oxidation reduction potential level. The ozone and the hydrogen peroxide are mixed with the water in a multicyclone unit to allow a peroxone reaction to occur that treats the water, and the treated water is returned to the reservoir.

Abstract: A polymer-free method and self-draining self-cleaning apparatus for treatment of water with high total dissolved solids including optional pretreatment, precipitation/flocculation, and separation. The pH is raised by addition of caustic soda and/or soda ash. In a vertical clarifier silo, the feed is gently mixed to cause dissolved solids to precipitate and agglomerate to form suspended flocculates. The clarifier includes an internal mixer surrounded by a cylindrical tube diffuser. Rotation of the mixer provides gentle dual circulation patterns within the clarifier that allow for flocculates of a predetermined size to settle from suspension. The clarifier may also include one or more vertical recirculation lines to recirculate some of the heavier flocculates at the bottom of the vessel into the mixer chamber to enhance precipitation via the seeding effect. The suspended flocculates are stripped from the feed water in a centrifugal separator. The clarifier silo may be trailer mounted for rapid deployment.

Abstract: A chemical/mechanical sludge dewatering treatment method and apparatus injecting SO2 into wastewater inflow streams and/or conventional process liquid streams containing suspended solids at a pH and dwell time to generate sufficient sulfurous acid with free SO2, sulfites and bisulfites to disinfect and self-agglomerate the suspended solids, acid leach heavy metals contained in and on the suspended solids into solution for subsequent separation, condition the suspended solids for subsequent chemical dewatering shedding water upon separation and drying, and mechanically separating and disposing of any solids from its chemically treated liquid fraction to create a Class A biosolid drying to less than 10% by weight water content.

Abstract: The invention relates to apparatuses, systems, and methods for the treatment of contaminated fluids, in particular water. The system is generally a continuous flow system including a multi-stage cavitation device, an electrocoagulation device, and an air flotation unit. The electrocoagulation device includes a plurality of interweaved cathode and anode plates. The anode plates are coated with an oxygen generating mixed-metal oxide coating. The air flotation unit includes a cavitation aerator and electrode blocks to introduce air bubbles into the fluid. Contaminants attach to the air bubbles and float to the fluid surface where they are removed as sludge. Treated fluid is passed through a final filtration system. The methods involve the processes imparted by the various apparatuses on the fluid.

Abstract: A method and apparatus provide at least one region of pulsed fluid treatment within a fluid treatment chamber. The instant invention prevents the formation and accumulation of contaminants within conduits and on equipment utilized in the transportation, delivery and processing of fluid columns. It may also be utilized to accelerate the separation of oil and water and increase the efficiency of oil/water separation equipment.

Abstract: A continuous flow reactor, including a cylindrical coagulation crystallizer, a funnel type protective baffle for static settling, and a conical static settler. A lower end surface of the cylindrical coagulation crystallizer is connected with an upper end surface of the conical static settler, and the funnel type protective baffle for static settling is connected with an inner wall of the cylindrical coagulation crystallizer.

Abstract: A valve arrangement includes various improvements useable in the context of a fluid additive system, such as a water softener. For example, the valve assembly may include a seal assembly engaged by a reciprocating piston, in which the seal assembly includes a minimal number of parts, is easily assembled, and can be easily inserted in the bore of the valve body without jeopardizing the integrity of the seals. The valve assembly may further include a quick-disconnect system which allows a “control head” including a valve actuation system and electronic controls to be disconnected from the rest of the valve arrangement with only a partial rotation of the control head. The valve assembly may also include a venturi used for drawing regeneration fluid into the system, and an associated venturi cleaner system which allows a user to unclog the fluid-flow orifice of the venturi without any disassembly of parts of the valve arrangement.

Abstract: A method of removing contaminates from sour water is provided. The method includes producing raw sour water within a syngas production system, and removing the contaminates from the raw sour water using a chemical reaction within a treatment unit to produce treated sour water. The treatment unit is in flow communication with the syngas production system.

Abstract: An improved draft tube spout fluid bed (DTSFB) mixing, handling, conveying, and treating apparatus and systems, and methods for operating are provided. The apparatus and systems can accept particulate material and pneumatically or hydraulically conveying the material to mix and/or treat the material. In addition to conveying apparatus, a collection and separation apparatus adapted to receive the conveyed particulate material is also provided. The collection apparatus may include an impaction plate against which the conveyed material is directed to improve mixing and/or treatment. The improved apparatus are characterized by means of controlling the operation of the pneumatic or hydraulic transfer to enhance the mixing and/or reacting by controlling the flow of fluids, for example, air, into and out of the apparatus. The disclosed apparatus may be used to mix particulate material, for example, mortar; react fluids with particulate material; coat particulate material, or simply convey particulate material.

Abstract: A system for collecting, treating and disposing of waste fluid includes a station that features transfer, flushing and mixing pumps as well as a bowl that holds the waste fluid. The waste fluid is collected in a container mounted on a cart. The cart container connects to the station so that the waste fluid is transferred from the cart to the station bowl by the transfer pump. The flushing pump has an inlet that communicates with a source of water and a disinfectant dispenser. The flushing pump is used to flush both the cart container and the station bowl, the latter of which communicates with a drain system. The flushing pump also delivers disinfectant to the waste fluid in the station bowl. The inlet and outlet of the mixing pump communicate with the bowl so that it mixes the bowl contents. Buffer is provided to the circulating waste fluid until the pH level drops to a predetermined level.