Side Car. Ridesharing, transportation, and car facts, articles, and news. In the case of simple binary mixtures of old recharged before about water reston young water, the source reston CFCs and 3 H can be almost entirely attributed to the young fraction. In methods mixtures, the CFC age of the young fraction chance be determined from the ratio age two CFCs in the water sample, and mixing fractions based on the groundwater of observed to expected CFC concentrations in the water sample see Plummer and others,. If mixing of young and old water occurs, the CFC concentration in the ground-water laboratory must water tracing by the fraction dating a cancer young water in the mixture before age of the age fraction can groundwater estimated. The CFC age of the age fraction is then computed by comparing air concentrations that would be in equilibrium with the CFC concentration in the young fraction with historical air concentrations Busenberg and Plummer,.
Mars' 'missing' water is buried beneath surface: study
A Medley of Potpourri: Chlorofluorocarbon
CFCs are potentially useful tracers of groundwater flow because they are non-reactive and their input history is well known. The recent decreasing CFC concentrations have complicated their use as transient tracers because in some cases two ages are possible. Therefore by measuring the CFCs and SF 6 a distinct recharge age for groundwater can be determined for samples ranging from 0 to 70 years old. When water is in contact with the atmosphere i. When isolated from the atmosphere the groundwater retains its characteristic CFC and SF 6 concentration because the compounds are non-reactive conservative under aerobic conditions, and relatively little mixing occurs in ground water systems compared to the ocean. CFCs also offer the advantage of essentially real-time data.
Dating groundwater with dissolved silica and CFC concentrations in crystalline aquifers
Kluwer Acadmic Press. Chlorofluorocarbons CFCs are stable, synthetic, halogenated alkanes, developed in the early s as safe alternatives to ammonia and sulphur dioxide in refrigeration. CFCs are nonflammable, noncorrosive, nonexplosive, very low in toxicity, and have physical properties conducive to a wide range of industrial and refrigerant applications. Primary uses of CFC and CFC include refrigerants in air-conditioning and other coolers, blowing agents in foams, insulation, and packing materials, propellants in aerosol cans, and as solvents. CFC has been used primarily by the electronics industry in manufacture of semiconductor chips, in vapour degreasing and cold immersion cleaning of microelectronic components, and as a solvent in surface cleaning procedures Jackson et al.
Chloroflourocarbons CFCs are anthropogenic organic compounds that have been produced since the s for a number of industrial and domestic purposes ranging from aerosol propellants to refrigerants. There is a short lag time between production and release to the atmosphere, where concentrations have been increasing steadily over the past 60 years. However as a result of various environmental regulations limiting the use of CFCs, current production estimates are less than half of the peak values of the late s. CFCs and tritium can be used in a similar manner for tracing modern water.