280 results about "Dissolved air flotation" patented technology

A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation ” technology such as magnetic separation, dissolved air flotation, vortex separation, or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used. The invention improves metal removal, lowers cost because fewer chemicals are used, produces less sludge, and reduces the discharge of toxic metals and metal precipitants to the environment. Magnetic separation is preferred for the separation of particles precipitated in the second stage. Similar methods can be employed for separation of other particulates from water. Particulates can also be removed by causing them to adhere to particles of expanded plastic, forming a floc lighter than water, so that the floc can be removed by flotation.

A clarification system for fluids in which particles are separated from the fluid by flotation and in which the buoyant media inducing the flotation is recycled. Flotation can be assisted by a flotation assistance device, such as dissolved air flotation.

A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation” technology such as magnetic separation, dissolved air flotation, vortex separation or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used. The invention improves metal removal, lowers cost because fewer chemicals are used, produces less sludge, and reduces the discharge of toxic metals and metal precipitants to the environment.

An apparatus for separating water from oil-based drilling fluid includes an separation tank, a chemical treatment apparatus having one or more de-oiling polymer preparation tanks, and a dissolved air flotation unit. Slop mud is directed into the separation tank where surfactant is added to separate the drilling fluid from oily water. The drilling fluid is drained for further processing. The oily water is removed by an outlet arrangement from the separation tank and directed to an initial treatment line. One or more de-oiling polymers are added to the oily water in the initial treatment line and mixed therewith. The mixture may then be directed to the dissolved air flotation unit where dissolved air is released into the bottom of the mixture. The dissolved air adheres to suspended solids in the mixture and lifts them to the top surface as a froth. The froth is skimmed from the top surface of the mixture and collected. The de-frothed water is reused or directed to a filtration system where it is prepared for discharge. A clarifying tank may be included after the de-oiling polymers are added to further separate the oil and water. The oil is removed from the top surface by a weir while the water is directed to the filtration system and discharged.

The present invention discloses an anaerobic biological wastewater treatment system for treating wastewater containing organic contaminants, which includes an anaerobic sludge bed reactor and a dissolved-air flotation tank. The anaerobic sludge bed reactor is used to decompose organic contaminants by way of an anaerobic biological treatment. The dissolved-air flotation tank is used to carry out liquid-solid separation on effluent from the anaerobic sludge bed reactor, so that anaerobic microorganisms entrained in the effluent can be recovered and recycled to the anaerobic sludge bed reactor, thereby enhancing the hydraulic loading of the anaerobic sludge bed reactor.

Methods for removing arsenic from water by addition of inexpensive and commonly available magnesium oxide, magnesium hydroxide, calcium oxide, or calcium hydroxide to the water. The hydroxide has a strong chemical affinity for arsenic and rapidly adsorbs arsenic, even in the presence of carbonate in the water. Simple and commercially available mechanical methods for removal of magnesium hydroxide particles with adsorbed arsenic from drinking water can be used, including filtration, dissolved air flotation, vortex separation, or centrifugal separation. A method for continuous removal of arsenic from water is provided. Also provided is a method for concentrating arsenic in a water sample to facilitate quantification of arsenic, by means of magnesium or calcium hydroxide adsorption.

The invention discloses a method for treating backflow fracturing fluid. The method is characterized by comprising steps of carrying out electric flocculation on the guar gum backflow fracturing fluid; carrying out air flotation sedimentation on waste fluid obtained after electric flocculation is carried out; carrying out electrochemical advanced oxidation treatment on supernatant fluid obtained after air flotation sedimentation is carried out; carrying out filtration treatment on waste fluid obtained after electrochemical advanced oxidation treatment is carried out and draining the waste fluid backwardly or externally. The method has the advantages that chemical flocculation and chemical oxidation are replaced by electric flocculation and electrochemical oxidation, dissolved air flotation and filtration are carried out, accordingly, introduction and dosage of new chemical agents can be effectively reduced, secondary intervention of chemically soluble interference ions in wastewater can be relieved, and the method is beneficial to reducing secondary pollution risks and the costs; the treated backflow fracturing fluid can be recycled for preparing fracturing fluid or being injected to strata again.

Methods of deoiling oily water such as SAGD and frac produce water. The oily water is treated with a natural coagulant selected from tannins and chitosan. A cationic and/or anionic flocculant may also be added to the treated oily water. The thus treated oily water may be subjected to conventional mechanical oil separation techniques such as hydrocyclonic separation, dissolved air flotation, entrapped air flotation, induced gas flotation, gravity filters, reverse osmosis filters, API, or Voraxial® bulk separators and the like.

The invention relates to a treatment method for waste water from processing acid-containing crude oil, and the method is used in the treatment of waste water containing naphthenic acid from the refining process of acid-containing crude oil. The method adopts a combined process including demulsification, cyclone oil removal, dissolved air flotation, ozone oxidation, MBBR and filtering to treat the wastewater containing naphthenic acid discharged from an electric desalting device in the crude oil refining process, and the outlet water after treatment reaches discharge standards. The method can prevent the treatment process of other waste water, such as oil-containing sewage and salt-containing waste water from the influence from naphthenic acid, and benefit the stable operation of oil separation, flotation, biochemical treatment and depth treatment units in final sewage works, so as to solve the problems of unqualified waste water from processing acid-containing crude oil and foaming of biochemical treatment, and provide a good basis for waste water reuse.

Disclosed herein is a water treatment system for connection to a water treatment plant (e.g. a dissolved air flotation device). The plant may have an inlet for the receipt of feed water (e.g. waste water) and an outlet for the discharge of treated water. The treatment system may comprise a first sensor disposed such that it is in fluidity communication with the feed water, and a second sensor disposed such that it is in fluidity communication with the treated water. The first and second sensors may be configured to sense parameters of the feed and treated water. The system may further comprise a first applicator (e.g. a pump) that is configured to discharge a treatment source (e.g. a chemical source) to the plant to treat the feed water. The disclosed system may be used to treat waste water (e.g. the treatment of effluent from oil refineries, petrochemical and chemical plants, natural gas processing plants, paper mills and general water treatment). The system has analogous applications in other processing methods that also use DAF, or very similar, systems, such as the processing of mineral ores and other such solid extraction processing methods.

The invention relates to a multi-phase flow pump reflux dissolved air flotation device, which is used for the treatment of oil-containing, papermaking and other industrial waste water and urban sewage. The device includes a water inlet pump, a multiphase flow dissolved air pump, an inlet water swirl distribution head, a backflow dissolved air swirl distribution head, a clear water collection pipe, a slag scraper, and a slag collection tank. Because the device adopts multi-phase flow pump to dissolve air and dynamic swirl to distribute water, it saves air compressors, dissolved air tanks and other equipment, and has the characteristics of simple structure, small footprint, energy saving and high removal efficiency.

The invention relates to a method for processing landfill leachate. The method comprises the following steps: carrying out efficient dissolved air flotation after collecting landfill leachate; adding slaked lime to the landfill leachate after air flotation treatment to carry out alkali adjustment; carrying out ammonia-nitrogen molecular sieve separation on the landfill leachate after alkali adjustment, and adding an acid to form an ammonium salt to recover ammonia nitrogen; carrying out biochemical treatment on the landfill leachate after ammonia nitrogen recovery; removing an organic matter, nitrogen and phosphorus in the landfill leachate; discharging up to the standard after multi-stage reflux adsorption on the landfill leachate after biochemical treatment. The landfill leachate is processed by using the technique disclosed by the invention, toxic and harmful substances such as high-strength ammonia nitrogen, non-biodegradable organic pollutants, heavy metal and the like in the landfill leachate are thoroughly removed, recycling of ammonia nitrogen resources is achieved, and the landfill leachate is discharged up to the standard.

A machine and methods using electro-chemical treatments, sedimentation processes and dissolved air flotation technologies for clarification of several kind of wastewater produced in industries, sewages, ponds, lakes, canals etc. The machine comprises of, feeding lines with multiple feeding point, a tank and further a collection tank. The wastewater is passed into the feeding line which may comprises of several feeding points for coagulants, flocculants, and other chemicals dosing into the flow of wastewater and may also comprises of a static mixer for mixing the coagulants, flocculants, and other chemicals with wastewater to agglomerate any solid particles and to accelerate separation of the solid particles in the tank. Once the solid are formed, they can go up or down, therefore to remove the suspended solids the outlet are rearranged depending on the suspended solids. Further, the machine is used for treatment of wastewater utilising multi pass concept to produce clean water.

The invention relates to an advanced treatment and recycling technique of cold rolling wastewater; wherein, a pretreatment step is carried out by combining conciliated aeration regulation, two-stage pH value regulation, dissolved air flotation and two-stage cooling. Firstly, the cold rolling wastewater enters a conciliated aeration regulation pool, water quality and water amount after conciliation are promoted to a first-stage pH valve regulation jar, then passes through a second-stage pH valve regulation jar, and the pH value of the wastewater is controlled to be between 6 and 9; the wastewater after regulation flows automatically into the dissolved air flotation, and oil contained in the wastewater and part suspended matters are removed; and dissolved air floats up from water and is subjected to two stages of cooling. A biochemical secondary treatment step adopts the technique of combing biological contact oxidation with a membrane bioreactor. An electrical adsorption desalting treatment step adopts an electrical adsorption desalting device to carry out deep desalting treatment. The technique has stable treatment effect, thus effectively removing pollutants such as the organic matters, the suspended matters, the oil and the salts, and the like contained in the cold rolling wastewater, and causing the cold rolling wastewater to be recycled so as to achieve energy saving and discharge reduction.

The invention discloses a pressure dissolved air flotation system, which includes an interconnected processing facility, a mixed reactor, a flotation device and a pressure dissolved air device. The process comprises adding wastewater in the mixed reactor and forming separable flocculation with the pharmaceutical added by dosing device, placing the wastewater treated by the mixed reactor in the flotation device and mixing it with dissolved air solution provided by the two dissolved air system pressure devices to make the bubble released from dissolved air solution adhere on the flocculation, and separating and discharging through the deslagging mouth of the flotation device. Through the pressure of dissolved air flotation device and the flotation device improved, it will reduce the volume of pressure dissolved gas cylinder, shorten the time required for dissolving air, prevent the plugging, and has compact structure and reasonable process.

The invention relates to a high-efficiency dissolved air flotation system which comprises an air flotation tank, a slag scraper, a slag discharge device, a water outlet device and an air-liquid mixing pump water inlet pipe, wherein the slag scraper, the slag discharge device and the water outlet device are arranged in the air flotation tank; the air-liquid mixing pump water inlet pipe is led out from the tail end of the air flotation tank, the air-liquid mixing pump water inlet pipe is provided with an air inlet pipe and connected with an air-liquid mixing pump and a microbubble generator through an air-liquid mixing pipe; a high-pressure saturated dissolved air water pipe led out from the microbubble generator and an external sewage inlet pipe are communicated with a dissolved air releaser positioned on the tail end of the water inlet pipe of the air floatation tank through a T-shaped mixer. Compared with the prior art, the high-efficiency dissolved air flotation system has the beneficial effects that dissolved air generated through the system is good in water stability and high in bubble density, microbubbles with grain diameters of about 5 micrometers and generated through the system are more easily adhered to suspended substances and oil droplets which are contained in sewage and a better removing effect can be achieved because the dissolved air ratio of dissolved air water inside the system can achieve 30%-35% and is simple in structure, easy to debug, stable in operation, stable and reliable in operation, conserved in energy, reduced in consumption and high in automation degree.