Biodegradable fluids

Polyglycols were the first basestocks to be formulated into biodegradable fluids and they are still used widely as fire-resistant lubricants and also in food processing. However, polyglycols lack the required biodegradability performance and are potentially toxic in water when mixed with lubricating additives. 

Vegetable and seed oils as well as some synthetic base stocks present a new class of biodegradable base stocks. These fluids (10) have excellent biodegradation properties as measured by criteria developed by the Environmental Protection Agency (EPA) or Organization of Economic Cooperation and Development (OECD). OECD 301 and EPA 560/6-82-003 measure the biodegradation of lubricants. These tests were developed to measure the degradation of oil, especially two-cycle ok, on waterways. Aquatic toxicity criteria toward fish is also found to be acceptable for this class of fluids as measured by EPA 560/6-82-002 and OECD 203 1-12. 

When antifreeze becomes unsuitable for use, either because of depletion of inhibitors, presence of corrosion products or corrosive ions, or degradation of the fluid, recycling and reuse of the antifreeze, rather than disposal, may be considered. Although ethylene glycol is readily biodegraded in typical municipal waste treatment faciHties, antifreeze disposal becomes problematic because the coolant may contain hazardous quantities of heavy metals picked up from the cooling system. Recycling may be economically preferred over coolant disposal and reduces the concern for environmental impact. 

Bilayer rigidity is a parameter which influences biodistribution and biodegradation of liposomes. In vitro a hydrophilic marker molecule (carboxyfluorescein) leaked much faster from the vesicles with bilayers in a fluid state than from bilayers in a gel state (Crommelin and Van Bommel, 1984). An indication of the bilayer rigidity can... 

Biodegradable drilling fluid formulations have been suggested. These are formulations of a polysaccharide in a concentration insufficient to permit a contaminating bacterial proliferation, namely a high-viscosity carboxymethyl-cellulose sensitive to bacterial enzymes produced by the degradation of the polysaccharide [1419]. 

Alkylpolyglucosides (APGs) are highly biodegradable surfactants [1344]. The addition of APGs, even at very low concentrations, to a polymer mud can drastically reduce the fluid loss even at high temperatures. Moreover, both fluid rheology and temperature resistance are improved. 

Fatty Acid Esters. Defoamers that are more environmentally acceptable than convential products are based on fatty acid esters of hydroxy alcohols, such as sorbitan monooleate [1908] or sorbitan monolaurate in combination with diethylene glycol monobutyl ether as a cosolvent [451]. These defoamer compositions are as effective as conventional materials, for example, those based on acetylenic alcohols are less toxic, especially to marine organisms, and are readily biodegradable. The defoamer compositions are used in water-based hydrocarbon well fluids during oil/gas well drilling, completion, and workover, especially in marine conditions. 

L. F. Nicora and W. M. McGregor. Biodegradable surfactants for cosmetics find application in drilling fluids. In Proceedings Volume, pages 723-730. lADC/SPE Drilling Conf (Dallas, TX, 3/3-3Z6), 1998. 

Propylene glycol, i.e., 1,2-propanediol (1,2-PDO), is an important commodity chemical. It is used as biodegradable functional fluids and as precursors for the syntheses of unsaturated polyester resins and pharmaceuticals (9-10). Propylene glycol is currently produced from petroleum-derived propylene via oxidation to propylene oxide and subsequent hydrolysis (9, 11). However, the rising cost of propylene provides an incentive to find a substitute to propylene for this... 

This technique was developed by In-Situ Fixation Company for increasing the efficiency and rate of biodegradation in deep contaminated soils using a dual-auger system. Mixtures of microorganism and required nutrients are injected into the contaminated soils without any excavation. The injection and mixing effectively break down fluid and soil strata barriers and eliminate pockets of... 

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