6433results about "Water/sewage treatment by flotation" patented technology

The invention discloses a method for comprehensive treatment of oilfield waste, which is characterized by comprising the process steps of cleaning and separation, ultrasonic separation, tempering and destabilization, oil-water separation, centrifugal separation, mixed curing, air floatation separation, adsorption filtration, flocculating settling, oxidization electrolysis, deep purification and permeable filtration. Thus, the oilfield waste is treated and utilized in a classified manner, so that sump oil is recovered, the solid phase achieves the discharge standard of oilfield sludge treatment design specifications (SY / T6851-2012) or is reutilized for construction material manufacturing, and the liquid phase achieves the sewage comprehensive discharge standard (GB8978-1996) after being subjected to water treatment.

A treatment system to efficiently remove lead from dust contained in extracted cement kiln combustion gas while reducing facility and running costs. A treatment system 1 comprising: a probe 3 for extracting a part of combustion gas, while cooling it, from a kiln exhaust gas passage, which runs from an inlet end of a cement kiln to a bottom cyclone; a classifier 5 for separating coarse powder from dust contained in the combustion gas extracted by the probe 3; a wet dust collector 6 for collecting dust from the extracted gas containing fine powder discharged from the classifier 5; and devices 12, 13 for feeding sulfurizing agent for sulfurizing lead contained in the kiln exhaust gas to the wet dust collector 6, and others. From the sulfurizing-agent feeders 12, 13 are preferably added the sulfurizing agents to a circulation liquid tank 7 or a pump 9 for circulating slurry. The slurry obtained by the wet dust collector 6 is separated into froth including lead and tail side slurry including gypsum by a flotation facility 14, 17, 18.

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.

In a vertical shaft bioreactor, improved devices and methods are provided for enhanced secondary and / or tertiary treatment of wastewater, including residential, municipal and industrial wastewater. The devices and methods of the invention are useful for enhanced secondary wastewater treatment, including BOD and TSS removal. Tertiary treatment can alternately or additionally be achieved in the bioreactor with nitrification of ammonia, with nitrification and denitrification, and with nitrification, denitrification, and chemical phosphorus removal. A vertical shaft bioreactor is also provided which achieves thermophilic aerobic digestion and pasteurization of sewage sludges, optionally to produce class A biosolids.

An electrocoagulation process for removing organic and metal contaminants from a pressurized waste fluid is disclosed in which a clarified waste fluid is produced when the pressure is released.