Abstract:
A wastewater feed containing an ultimate BOD/COD ratio >0.6 is well-suited for especially acclimated thermophilic and/or caldo-active living micro-organisms ("hot cells") which thrive in an autothermal aerobic (ATA) reaction zone having an ATA bioreactor ("ATAB") operating at substantially ambient atmospheric pressure in combination with a MF or UF membrane filtration device from which a solids-free permeate may be withdrawn. This combination, of ATAB and membrane device is a "membrane bioreactor" (ATA MBR), which operates autothermally with a feed containing biodegradable organic materials having a BOD of at least 5,000 mg/L, preferably at least 10,000 mg/L (10 g/L) with a minor portion of "municipal" wastewater or domestic sewage. Operation of the ATAB, preferably in the thermophilic range from 45.degree. C.-75.degree. C., with constant HRT from 1 to 12 days, is contingent upon maintaining a stable population of live hot cells. Such cells enhance the biokinetics of degradation and allow operation of the ATAB at higher COD loading and a lower concentration of TSS, than would be possible at a lower temperature. A surprisingly high membrane productivity allows production of much less sludge to be disposed of outside the system, than would have to be disposed of with a conventional mesophilic reactor in normal operation with a HRT of less than 24 hr. A combination of an MP MBR with an ATA MBR is highly effective when the MPB produces high BOD concentration mixed liquor for destruction by the ATAB.
Abstract:
A system is provided to treat wastewater from a metal-working facility, such as an automotive manufacturing plant in a bioreactor using live microorganisms. Such wastewater contains waste fluids which are a mixture of relatively easily biodegradable fats and oils, much less easily biodegradable synthetic fluids, oils and greases, and nonbiodegradable material including inorganic finely divided solids such as metal and silicon carbide particles. Such waste fluids require a hydraulic retention time (HRT) and a solids retention time (SRT) which is 10 times greater than for sewage. High quality water is separated from suspended solids which are removed from the reactor at an essentially constant rate and fed to an ultrafiltration membrane. Concentrate is recycled to the reactor, except for a bleed stream to remove solids periodically. The membranes acquire a long and effective life despite large variations in membrane flux, because of a permeate recycle which permits operation of the bioreactor at constant volume; permits flow of feed wastewater to the reactor at constant flow rate; and allows operation of the membrane modules at a relatively low pressure in a narrow range which does not damage the membranes. Such operation of the bioreactor allows one to use a reactor which is one-half the size (volume) than one which would be required with a system without a permeate recycle. Effective and long-lived operation of the membranes is obtained by filtering out (through a 140 mesh screen) all solids greater in diameter than about 106 .mu.m. Pilot plant tests conducted with wastewater from automobile manufacturing plants over a period of more than a year provide evidence of the surprising effectiveness of the system over a prolonged period.
Abstract:
A process for recovering used lubricating oils, and oils recovered using the process. In a first embodiment (for used industrial oils), the used lubricating oil is mixed with clay in a reactor. The mixture is preferably heated to between 80 and 200 degrees Celsius. The temperature should not be too great, to avoid “cracking” the oil (i.e., breaking molecular chains in the oil). After a certain period of time, the mixture is pumped through filters. Cakes of clay and contaminants remain in the filters, while the oil emerges without the contaminants. A second embodiment (for removing ash or soot, very fine carbon particles and other organic compounds from used motor oils) is the same as the first embodiment, except that before the mixture is passed through the filters, a centrifuge is used to remove most of the clay contaminated with soot, so that it will not block the filters.
Abstract:
A method suitable for treating used oil to remove ash and metal contaminants therefrom with minimum oxidation of the oil, the metal including at least one of the components of iron, lead, copper, zinc, sodium, magnesium, and calcium, to provide a highly purified oil product having less than 10 ppm of at least one of the contaminants and less than 0.15 wt. % of ash content. The method comprises providing a body of oil to be purified and chemically treating the oil to condition ash and metals contained therein to facilitate removal of ash and metal during membrane purification of the oil. A porous inorganic membrane module having a high pressure side and a low pressure side is provided and the chemically treated oil is introduced to the high pressure side of the membrane module to provide an oil permeate on the low pressure side and an ash and metal-rich concentrate on the high pressure side thereby separating ash and metals from the oil to provide the highly purified oil product at an improved level of throughput of the membrane compared to feed oil not chemically treated.
Abstract:
A method for the molecular filtration of predominantly aliphatic hydrocarbon liquids (e.g. spent diesel lubrication oil, crude oil or pipeline blend crude oils and heavy oils, and bitumen), wherein, at a viscosity less than 600 centipoise, the predominantly aliphatic hydrocarbon liquid is passed through a membrane, having at least a swelled outer layer on the high pressure side comprising a microporous, membrane of an aliphatic hydrocarbon liquid swellable, polysulfone compound, at a pressure differential in the range 1 to 100 atmospheres oil. The microporous membrane having been swelled in the aliphatic hydrocarbon liquid from having a molecular weight cut off less of than 20,000 when measured in an aqueous medium to, after adsorption of hydrocarbon liquid and having been swelled thereby, a molecular weight cut off less than 4,000 when measured in hydrocarbon liquid, so that oil depleted in the substance to be filtered therefrom permeates the membrane. The viscosity of the crude oil may be reduced by heating or adding a solvent to it. The invention is useful for separating, for example, nitrogen, sulphur, aluminum, chromium, copper, nickel, vanadium and asphaltenes from fossil derived, predominantly aliphatic hydrocarbon liquids.
Abstract:
Disclosed is a system for separating impurities from a hydrogen-free fluorinated lubricant. The lubricant is passed through a filter apparatus containing an adsorbing material. The lubricant is then passed into a degasser unit to remove volatile impurities from the lubricant. The degassing unit has an area of closed suction. A pressure measuring device measures the pressure in the closed area and, based on this measurement, a control apparatus controls the degassing unit. A monitoring unit monitors the quality of the filtered lubricant.
Abstract:
A portion of the oil-in-water emulsion used as a lubricant/coolant in the shaping of metal articles such as containers is subjected to a reverse osmosis or ultrafiltration process to concentrate the oil portion and separate a water permeate. The oil concentrate is reincorporated in the remaining portion of the coolant and the permeate is used as rinse water to remove oil residues retained on the article from the metal shaping operation. The coolant is then reconstituted with the oil residue rinsed from the article.
Abstract:
Used lubricating oils are first heated to 200.degree.-500.degree. C, optionally with added steam, and then filtered through a membrane such as an ultra-filtration membrane. The latter has preferably a cut range of from 5,000 to 300,000.
Abstract:
A process and system for recovering gel-mass from a gel-mass-containing waste material. The process comprises retrieving the gel-mass-containing waste material from an encapsulation process; melting the retrieved waste material to provide an oil phase and a non-oil phase; retrieving the non-oil phase to produce a recovered gel-mass; and recycling the recovered gel-mass for combination with fresh encapsulating material to provide a combined encapsulating material for use in encapsulating a same lot of the same product which was being encapsulated in the step that produced the gel-mass-containing waste material from which the gel-mass was obtained. The system comprises a heated accumulator for receiving and melting the gel-mass-containing waste material to provide an oil phase and a non-oil phase; a pumping system; an optional mixer; and a control system.
Abstract:
The present invention proposes a new formulation for the making of a cellulose acetate hollow fiber membrane for ultrafiltration with high water permeability, capable of oil and water separation with minimal energy consumption and low fouling tendencies.