282 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.

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 invention discloses an oil removing pretreatment technology for petroleum oil refining wastewater. According to the oil removing pretreatment technology, a water collecting tank with gratings is used for separating sand and sludge; a three-phase cyclone liquid separation floating oil collecting and discharging adjusting tank is used for achieving separation of water, oil and residues; a cyclone oil coarse graining polymerization oil-water separator is used for removing fine oil grains; a dissolved air flotation device is used for demulsification and flocculation reaction, wherein air bubbles and suspended solids in wastewater make contact for adhesion and float upwards, and the standard is met through residue scraping. The technology is simple, the structure is scientific, the three-phase cyclone liquid separation floating oil collecting and discharging adjusting tank, the cyclone liquid coarse graining polymerization oil-water separator and the dissolved air flotation device jointly serve as the core treatment scheme, oily wastewater is pretreated through the density difference of oil and water based on the fluid dynamics principle, a physical method and a chemical method act jointly, and the oil content in the pretreated oily wastewater is smaller than or equal to 20 mg / L and reaches the standard. The oil removing pretreatment technology is large in daily treatment amount, high in oil removing efficiency, remarkable in oil collecting effect and considerable in economic benefit, and the water content of the recycled waste oil is 5% or lower.

The invention relates to a cold rolling waste water advanced treatment reuse system, which comprises a pretreatment process, a biological two-stage treatment process and an electric adsorption desalting treatment process. The pretreatment process comprises a uniformly-adjusting tank, a two-stage pH adjusting groove, a dissolved-air float, a middle pond, a cooling tower, a cooling pond, a plate type heat exchanger and the like. The biological two-stage treatment process comprises a biological contact oxidation pond, an inclined plate settling tank, a membrane biological reaction tank, a reactor, a cleaning box, a suction pump and the like. The electric adsorption desalting treatment process comprises an electric adsorption raw water pool, an electric adsorption moudle, a clean water tank, a reuse water pump, a regeneration pump, a sewage drain pump, an electric adsorption enriched water tank and the like. The cold rolling waste water undergoes the pre-treatment process comprising the uniform aeration adjustment, the two-stage pH adjustment and the dissolved-air flotation, the biological two-stage treatment step provided with the membrane biological reactor for contact oxidation and the electric adsorption deep desalting treatment process, thereby effectively removing pollutants in the cold rolling waste water, reutilizing the cold rolling waste water and achieving the aim of energy conservation and emission reduction.

The invention discloses a high-suspension easy-to-biochemically treated wastewater treatment method, which is applied to the treatment of various kinds of high-concentration easy-to-biochemically treated organic wastewater. The method comprises the following steps of 1, collecting wastewater, and performing advanced solid-liquid separation in a dissolved air flotation way; 2, performing anaerobic decomposition on the separated wastewater by using anaerobic and facultative tanks; 3, causing the decomposed wastewater to enter an MBR (membrane biological reactor) process system; and 4, disinfecting and sterilizing effluent obtained by an MBR process to discharge water reaching standards by using sodium hypochlorite. According to the wastewater treatment method, high-concentration easy-to-biochemically treated wastewater can be effectively treated, the construction fund can be greatly saved, a small land is occupied, and the method is stable in running, low in cost and particularly suitable for industrial production.

A system is disclosed herein for treating wastewater liquid by utilizing aerobic biological species. The contaminated wastewater stream is pretreated in a dissolved air flotation system to remove suspended solid waste, including large particles such as fats, grease, and physically emulsified oils. The purified wastewater containing dissolved waste is thereafter oxygenated and further decontaminated in a bioreactor tank. Biological species in the bioreactor tank consume oxygen and perform bodily functions that converts dissolved waste into easily removable carbon dioxide and suspend solids. Oxygen consumed by the biological species is replenished by pumping the wastewater though a liquid-oxygen mixer. A controller regulates the speed of the pump based on real-time oxygen concentration measurements provided by a corresponding oxygen probe disposed within the wastewater in the bioreactor tank.

The invention discloses a method for treating wastewater of a fibre-board plant. The method is characterized by including the combination of technical skills of the following three parts: a pretreatment system, a biochemical treatment system and an aftertreatment system; wastewater from production is respectively led into a filter and a centrifuger; after being processed by the step of slag removal, the wastewater flows into a horizontal sedimentation tank, a pre-aeration regulation tank and an iron aeration tank or a vertical sedimentation tank and then is processed by dissolved air flotation; the discharged water is respectively pumped into a turn-back flow anaerobic tank with filter materials and an oxidation tank and then flows into an inclined-tube sedimentation tank to settle; and after suspended substances in the wastewater are removed by a filtration tank, the wastewater is discharged while reaching standards. The method has the advantages that the efficiency of removing the suspended substances is high, water is circularly and repeatedly used, water consumption is reduced, the discharge amount of the wastewater can be reduced by more than 300 tons each day, the occupation of land of equipment is low, the operation is simple, and the running cost is low. Extruded wood slag and sludge can be used as energy to be led into an energy centre to combust, secondary pollution is not caused, and the treated wastewater can meet the requirement of primary standard in the Integrated Wastewater Discharge Standard GB8978-1996.

A dissolved air flotation clarifier for removing impurities from a liquid to be clarified. The dissolved air flotation clarifier includes a housing having an inlet for receiving a liquid to be clarified. The housing further includes a reaction zone, a clarification zone and an effluent channel. The reaction zone has at least one saturated water distributor and at least one dissolved air flotation nozzle operably connected to the at least one saturated water distributor to receive saturated water from the at least one saturated water distributor. The dissolved air flotation nozzle is configured to release micro-bubbles from a saturated water so that the micro-bubbles can mix with the liquid to be clarified to remove impurities from the liquid to be clarified. The clarification zone includes a flow control member for controlling the flow of the mixture of micro-bubbles and liquid in the clarification zone to ensure that the area surrounding the inlet to the effluent channel has little or no micro-bubbles to prevent or significantly reduce micro-bubbles from becoming entrained in a clarified liquid passing through the effluent channel.

A dissolved air flotation system and method for purifying fresh water. The system is self-contained within a standard shipping container, with all components disposed in-line within the shipping container. Float is removed from the flotation tank with a skimmer that drives float downstream onto a conveyor belt, and the conveyor belt conveys float away from the flotation tank, in the downstream direction, and deposits the float in a collection tank. Clean water may be drawn from the flotation tank continuously, while float may be removed periodically.