Aliphatic hydrocarbons wastewater

In a method described by Ryzhova et al. [30] for the determination of aliphatic hydrocarbons in wastewater sludges the hydrocarbons were extracted from sludge using a mixture of pentane and hexane. Metal salts... 

Anaerobic-aerobic processes have a high potential for the treatment of pulp mill wastewater containing xenobiotic compounds. The pulp and paper industry is under great pressure to remove chlorophenols, chlorinated aliphatic hydrocarbons, and chlorinated dioxins and furans from wastewater. The Canadian government requires that pulp mill effluent contain no measurable level of dioxins or furans (Murray Richardson, 1993)- Such regulations require novel wastewater treatment technologies for the complete removal of target compounds. 

Transport of solutes through the LM occurs by either passive transport or by carrier-facilitated transport. Phenol, for example, is soluble in both phases, and treatment of an aqueous phenol solution with an emulsion results in a lowering of the external concentration of phenol as it passively diffuses through the hydrocarbon (HC) layer and into the internal aqueous phase. Equilibrium is reached when the concentrations of phenol in both aqueous solutions are equal (assuming no other conditions are present which would alter the distribution between the aqueous and HC phases). One way to alter this equilibrium is to trap phenol inside with a sodium hydroxide solution. Phenol ionizes at high pH, and the phenolate ion cannot permeate a HC layer trace amounts of phenol have been completely removed from wastewaters by this system (10, 11). This exclusion of charged molecules by the aliphatic hydrocarbon LM layer is desirable in some applications, but to employ LM enzyme reactors and/or separation systems with amino acids, it is necessary to incorporate carriers into the HC phase. 

LABs. Despite of their potential as anionic surfactants indicators , there is little information on then-recovery from the dissolved phase of wastewaters. According to onr results, LLE is an efficient extraction technique for wastewaters (Table 1), but for large sample volumes open porous PUF can still be nsed. LABs coelute with aliphatic hydrocarbons in the fractionation procednre used, thus their quantitation shonld be performed by HRG-EI MS, unless further fractionation is carried out for GC FID analysis ". 

Table 3.3. Industrial products and processes that yield aliphatic hydrocarbons in untreated wastewater. 

Uses Defoamer for aq. systems, metalworking fluids, cleaner fonnulations, paints/ coatings, paper processing, paperboard, wastewater treatmenL textiles Features Alkali resistant exc. foam knock down, persistence Properties Tan liq., mild odor sol. in aliphatic hydrocarbon soivs. insol. in water sp.gr. 0.8 dens. 7.0 Ib/gal low vapor pressure b.p. 480 F flash pt. (PMCC) > 93 C 100% act. 

Characterization of Volatile Fraction. Volatile organic compounds found in oily wastewaters consist primarily of lower-molecular-weight aliphatic and aromatic hydrocarbons. Because of its relatively high vapor pressure, this fraction is quite often lost during analysis of oily wastes. For this reason a separate procedural step was incorporated into the overall scheme for analysis of the volatile fraction. An unfiltered sample of oily waste is used in this determination. The volatile fraction is separated from water by means of nitrogen sparging and collected in an activated carbon absorption column. The collected compounds are desorbed into carbon disulfide and analyzed by GC. 

Naphthenic acid are most significant environmental contaminants. They are comprised of a large collection of saturated aliphatic and alicyclic carboxylic acids found in hydrocarbon deposits (petroleum, oil sands bitumen, and crude oils). Moreover, they are toxic components in refinery wastewaters and in oil sands extraction waters. In addition, there are many industrial uses for naphthenic acids, so there is a potential for their release to the environment from a variety of activities. Studies have shown that naphthenic adds are susceptible to biodegradation, which decreases their concentration and reduces toxidty. 

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