790 absence of (Table I).
ANALYTICAL CHEMISTRY polyoxyethylene
or
polyoxypropylene
groups
LITERATURE CITED
(1) Flanagan, T. L., Jr., Drennen, T. J., and Goetchius, G. R., Soap Sunit. Chemicals, 24, No. 4, 163 (1948). (2) Gnamm, H., “Die Losungs und Weichmachungsmittel,” p. 330, Stuttgart, 1941. (3) Haakh, H., v. Candie, D., and Mobus, m7., MelLiand TestiZber., 32,699 (1951).
(4) Newburger,
(5) (6) (7) (8) (9)
S. H., J . Assoc. Ofic. A v . Chemists, 34, 109 (1951). Rosen, M. J., ANAL.CHEM.,27, 111 (1955). . Proc., 1950. Shiraeff, D. A., Chem. Specialties M ~ T sAssoc. Simon, L., Compt. rend., 125, 536 (1897). Ibid.vP.1105. Wurzschmitt, B., 2. anal. Chem., 130, 105 (1950).
RECEIVEDfor review October 2 5 , 1954. Accepted December 20, 1954. Presented before the Division of Polymer Chemistry a t the 126th Meeting of the AMERICAN C H E M I C A L SOCIETY, New York.
Identification of Petroleum Refinery Wastes in Surface Waters A. A. ROSEN and F. M. MIDDLETON Robert A. Taft Sanitary Engineering Center, U. S.
Public Health Service, Cincinnati,
Because the most significant pollution effect of petroleum refinery wastes is the production of tastes and odors in receiving waters, there is a need for nonsubjective methods of identification with sensitivity comparable to odor judgments. The aliphatic and aromatic hydrocarbon fractions separated from the wastes of five refineries showed corresponding infrared spectral patterns sufficiently characteristic to suggest their use in identification. The organic materials in three samples of surface waters containing varying amounts of refinery wastes were concentrated with active carbon. Hydrocarbon fractions, separated by chemical and chromatographic procedures, were identified by the resemblance of their infrared spectra to the spectral patterns of refinery waste hydrocarbons. This method provides chemical evidence, independent of odor evaluations, of the presence of low concentrations of petroleum refinery wastes in surface waters.
B
ECAUSE of their large volumes and high odor intensities (6, 7 , 17), the most significant pollution effect of petroleum refinery process water effluents is the production of tastes and odors in receiving waters (1, 6, 6, 15). Indicative of the nature of this problem is the active current research on pollution abatement and the development of necessary analytical procedures (8). The major organic component of petroleum refinery wastes is the neutral group, consisting of hydrocarbons and closely related compounds which do not form salts with acids or bases. il large proportion of the odorous organic components is contained in the neutral group ( 1 7 ) . Such compounds are resistant to biological and chemical action (1, 5 ) ; consequently, the odor effects persist beyond the immediate vicinity of the waste discharge. Even in instances where the petroleum odor in water is recognizable, it is seldom possible by nonsubjective methods to establish the presence of petroleum products. Gross pollution has been detected by the presence of an oil film on the incoming water basins ( 1 ) and by paper chromatography of oil recovered from harbor slicks (9,18). Melpolder, Warfield, and Headington ( I S ) have recently published a very sensitive procedure for the identification and determination of volatile hydrocarbons in Tvater. The method is limited to hydrocarbons boiling up to 400” F. and requires the use of a mass spectrometer. Descriptions have been published ( 2 , 1 7 ) of the use in this laboratory of active carbon filters for the recovery and characterization of organic materials present in very low concentrations in surface waters. An application of these procedures ( 1 4 ) has been partially successful in demonstrating the presence of refinery wastes in water supplies drawn from a lake in the vicinity of the dis-
Ohio
charge points of a number of refineries. In this method, organic substances were recovered from the water by adsorption on activated carbon and subsequent elution, then were compared with a sample of refinery waste materials on the basis of elemental analysis, physical and chemical properties, and infrared spectra. The presence of oxygenated compounds, arising both from oxidation of the petroleum waste and from the presence of other types of pollutants, obscured the hydrocarbon properties serving as a basis for identification, particularly the infrared spectral characteristics. Petroleum hydrocarbons, consequently, were not clearly recognizable. To minimize this interference, the method described in this paper utilizes adsorption chromatography on silica gel to remove oxygenated substances. In addition, the hydrocarbons are separated into an aliphatic and an aromatic fraction. Infrared spectra of corresponding hydrocarbon fractions of five refinery wastes showed a remarkable degree of similarity, suitable for use in identification. Similar infrared spectra were shown by the corresponding chromatographic fractions of organic compounds recovered from surface waters polluted n-ith refinery wastes. DEVELOPMENT OF METHOD
Chromatography. Adsorption chromatography is regularly applied to petroleum products, but its application to undistilled materials has been less frequent (4,10-12). Redgewood and Cooper ( 1 9 ) have detected polynuclear hydrocarbons in gas works waste by a combination pf chromatography and ultraviolet spectroscopy. I n developing the present procedure, preliminary experiments to evaluate adsorbents and operating conditions were performed. -4 sample containing equal weights of n-octadecane, 1-methylnaphthalene, and methyl stearate was chromatographed on five adsorbents: silica gel (Davison Codes 912,923, and 950), alumina (Fisher A541/2), and carbon (Nuchar C-190 unground). Effluent portions of constant volume were collected separately, the quantity of residue in each fraction wag estimated after evaporation of the solvent, and the composition of each residue was estimated from its infrared spectrum. Silica was the best adsorbent. The three silica gels were nearly equivalent in separation efficiencv, but on the basis of flow characteristics, minimum discoloration, and economy, the Code 950 gel was slightly preferahle. Separation was also improved by wetting the adsorbent with the first solvent before adsorption of the sample. Optimum volumes of eluting solvents 11-ere determined in similar experiments. Recovery of Chromatographic Fractions. The quantitative recovery of petroleum materials from solution in volatile solvents is generally recognized to be a complex problem (8). The conditions finally adopted resulted in complete removal of solvent (as %vasshown by infrared spectra) with the attainment of con-
79 1
V O L U M E 27, NO. 5, M A Y 1 9 5 5
gel was 18 grams. The adsorbent was wetted with the first solvent, 2,2,4trimethylpentane (iso-octane); the required volume was 17 ml. Five times this volume, 85 ml., of each solvent was used in the subsequent elutions. A sample not exceeding 1.5 grams of the neutral fraction of the carbon filter extract, disPROCEDURE solved in 4 ml. of iso-octane, was adsorbed on the top of the adsorbent column, then the remainder of the 85 ml. of solvent The methods employed in obtaining samples of the organic was percolated through the column. The effluent, containing the aliphatic hydrocarbon fraction, was collected in a tared flask. components of surface waters and refinery wastes and of isolating Similarly, the aromatic hydrocarbon fraction was eluted with the neutral fractions from the samples have been described (2,171. benzene and the oxy (polar) fraction with a mixture of equal volumes of chloroform and methanol. Silica gel (Davison Code 950) was tamped to a height of 10 The neutral fraction of the organic substances obtained from cm. in a glass column 19 mm. in diameter. The weight of silica some surface water samples contained a l a r g e p r o p o r t i o n of WAVE NUMBERS IN cb@ material insoluble in iso-octane. In suchinstances, the sample was dissolved in benzene and chromatographed with the same solvent, yielding a fraction containing both aliphatic and aromatic hydrocarbons. This fraction was then further separated by the usual chrom a t o g r a p h i c procedure. Each effluent fraction Lras concentrated to about 5 ml. by distillation or evaporation, then residual solWAVE LENOW IN MICRONS vent was removed by evacuating to 30 to 50 Figure 1. Refinery waste neutral fractions mm. of mercury pressure a t 50' C. for 1.5 h o u r s . E b y (3) h a s WAVE NUMBERS IN C M ' published a similar pro100 1w bt5 15W 1100 1100 12W 1100 Im , 900 2ca cedure for the chromaI I I I I tographic separation of high boiling petroleum products into the same three kinds of fractions. Infrared spectra of the solvent-free aliphatic and aromatic fractions were obtained by useof a Bairddoublebeam recording instrument with sodium chloride prism and windows, using a 0.10-mm. m j c r o c e l l a t normal scanning speed (about 1 micron per minute). Infrared ppectra of the oxy fractions were not WAVE LH6W IN MICRONS useful for identification purposes. Figure 2. Aliphatic fractions of refinery wastes
stant weight of high boiling residues, such as those in motor oil. Partial loss of volatile solutes, such a$ n-decane, could not be avoided.
WAVE NUMBERS IN CM' I
WAVE W6lH IN MICRONS
Figure 3.
Aromatic fractions of refinery wastes
CHARACTERISTICS OF REFIIVERY WASTES
Samples of the organic materials in the waste effluents of five petroleum refineries were recovered by adsorption on activated carbon filters, in connection with a previous investigation of odor components. The samples described in this paper areidentified as .4-2, B-3, C-1, D-1, and E-1 in Table I1 of the earlier publica-
792
ANALYTICAL CHEMISTRY
tion (17), which also describes in detail the sample collection procedure. Recoveries of organic m a t e r i a l s ranged from 7.5 to 87 p.p.m. of the waste; the neutral fractions comprised 58 to 88% of the recovered material. Odor intensities of the total extracts and the neutral fractions showed little difference between refineries. The physical Figure 4. Aliphatic fraction from canal water properties of the neut r a l f r a c t ions-Le., density, refractive index, and boiling range -were too variable to serve as a means of identification. Figure 1 depicts the infrared spectra of all the neutral fractions, recorded on the same chart and using the same cell and instrument gain setting. T h e r e s u l t s demonstrate a general pattern; however, in the 9 10 I1 I3 15 I2 WAVE LENGTH IN MICRONS “fingerprint” region between 9 and 15 miAromatic fraction from canal water crons the variations are sufficient to minimize the value of these spectra for recognition of refinery wastes. T h r a glass filter, 3 inches in diameter and 15 inches long, filled with infrared spectra of all the aliphatic hydrocarbon fractions obunground active carbon, Nuchar C-190 (Industrial Chemical tained by chromatography of the neutral fractions are contained Sales Division, West Virginia Pulp and Paper Co., S e w York, in Figure 2. I t is evident that a characteristic pattern is preX. Y.). The sand was discarded and the dried carbon was sented by these spectra. A similarly characteristic pattern is reexhaustively extracted with chloroform, yielding 1.38 p.p.m. of a vealed by the infrared spectra of the aromatic hydrocarbon fracdark oil with characteristic petroleum odor, together vith 0.06 tions (Figure 3). Although the corresponding fractions of the p.p.m. of free sulfur in solid form. Group separation results wastes from the five refineries varied slightly in their spectra, were: 66’% neutral compounds, 2% bases, 2% acids, 8% phenols, these variations were with few exceptions in the strength rather and 22% loss. The loss was attributed to compounds with unthan the position of the absorption hands, representing differing favorable partition between ether and water. By chromatogproportions of common components. raphy, the neutral group separated into 33% aliphatics, 31% The proportions of the three chromatographic fractions rearomatics, and 13% oxy compounds. Figures 4 and 5 are the covered from the wastes of the five refineries varied much more infrared spectra of the aliphatic and aromatic fractions. Figure than did the infrared spectra of the fractions. The recoveries are 4 fits within the limits of Figure 2, and Figure 5 matches Figure 3 presented in Table I. Losses encountered xere primarily due to closely. The results are considered to confirm the presence of evaporation of more volatile components during removal of the refinery wastes in the canal water. eluting solvents. The characteristic petroleum odor was present principally in the aromatic fraction. The oxy fraction resembled asphalt in appearance and odor. Table I. Recovery of Chronlatographic Fractions Sulfur was determined in the aliphatic and aromatic hydrofrom Neutral Fraction carbon fractions of the neutral components of wastes collected Aliphatics, Aromatics, Oxy Compounds, Not Recovered , at three of the refineries. The results, shown in Table 11, indicate Refinery % % % % that sulfur compounds, probably cyclic sulfides and substituted 18 17 benzothiophenes (16‘)) are regularly present in the chromato13 33 graphed hydrocarbon fractions. Similar values for sulfur con3 tent have been reported for similar chromatographic fractions of crude oil (11). The values in Table 11, however, appear to be Table 11. Sulfur Content of Refinery Waste Hydrocarbon Fractions too variable to offer a means of identification of refinery wastes. Refinery
APPLICATION O F METHOD
A total of 2480 gallons of canal water was pumped through a sand prefilter and then into Canal Bordering R e k e r y Area.
B C E
rlliphatics, % 0.4 1.6 0.4
Aromatics, % 5.4
4.3
1.3
V O L U M E 27, NO. 5, M A Y 1 9 5 5
793
Lake Water Near Refinery Outfalls. A domestic water supply is drawn from a large lake a t this point. Problems involving
these two samples resembled those of refinery wastes, but they were obscured by the presence of oxygenated compounds. petroleumlike taste and odor in this supply have been encounChromatography of the neutral group yielded 42% aliphatics, tered. Organic materials were recovered by pumping 20,160 26% aromatics, and 18% ouy compounds. The infrared spectra gallons of raw xater through a sand prefilter and then through a of the aliphatic and aromatic fractions are shown in Figures 6 carbon filter consisting of a %foot length of iron pipe 4 inches in and 7. In this euample, chromatography did not completely diameter, filled with 4-10 mesh Cliff char granular active carbon remove the oxygen compounds, as demonstrated by the 5.8(Cliffs Dow Chemical Co., Marquette, Mich.). The recovery of micron carbonyl band and the general absorption of the 8- to organic materials from the water amounted to 184 p.p.b., 45% 10-micron region. In other respects the curves match closely of which was separated as the neutral fraction. Both the carbon the spectra of the corresponding fractions obtained from refinery filter extract and the neutral fraction prepared from it had \Tastes. These results are strong evidence for the presence of strong refinerylike odors. Infrared spectral characteristics of refinery waste materials in the lake water sample Lake Water a t a Distance from R e f i n eries. Carbon filters were operated on both the rav and finished water supplies a t a city located on the lake m e n t ioried a b o v e , about 10 miles from the refineries. Water taste and odor problems a t this city have been in part attributed to refinery wastes, this conclusion being based on the qualitative odor judgments of the water plant operators. From 8120 gallons F i g u r e 6. .Aliphatic f r a c t i o n from l a k e water of the raw water, preIWO
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an 18-inch-long filter containing 20-mesh active carbon, there waa recovered 41 p.p.b. of organic material. At the same time, 9750 g a l l o n s of f i n i s h e d water passed through a similar carbon filter yielded 54 p p.b of organic extract. Each extract consisted of t \ i o lalers: a lower brown wax and an
materials The tlvo e x t r a c t s w e r e combined for group separation, yielding 34% n e u t r a l s , i %bases, 13% acids, 20% phenols (containing weak acids), and 1 5 % aldehydes The odors of the filter extracts and the neutral fraction did not resemble refinery wastes.
A N A L Y T I C A L CHEMISTRY
194 WAVE NUMBERS
IN CMI
WAVE LENGTH IN MICRONS
Figure 9.
Lake water aromatics, distant from refineries
on the properties of the hydrocarbon components. The characteristics of the hydrocarbons in other types of wastes, and consequently their possible interference in the method, have not yet been d e t e r m i n e d . Evidence provided by this method, therefore, offers p r e s u m p t i v e , not conclusive, ident i f i c a t i o n of water p o l l u t a n t s of petroleum origin. Wastes containing hydrocarbon fractions spectrally distinguishable from those described here constitute a logical field for extension of this method. ACKNOWLEDGMENT
The authors are grateful t o H a r r y Braus and John Inskeep, who prepared some of the samples of organic materials from refinery wastes a n d surface waters. hlicroanalyses were Figure 10. Aromatics distant from refineries, purified performed by Paul W. K. R o t h e m u n d , those in the original filter extracts. Chromatography of this Antioch College, and by Clark Microanalytical Laboratory, fraction yielded 32% aliphatics, 17% aromatics, and 51% oxy Urbana, Ill. compounds. The infrared spectrum of the aliphatic fraction LITERATURE CITED (Figure S), though showing slight contamination by oxygen compounds, probably esters, still revealed the usual aliphatic Besozzi, L., and Vaughn, J. C., J . Am. Water Works Assoc., 41, 1035 (1949). hydrocarbon characteristics. The aromatic fraction could not Braus, Harry, Middleton, F. M., and Walton, Graham, ANAL. be identified from its spectrum (Figure 9) as petroleum hyCHEM.,23, 1160 (1951). drocarbons because of its clearly high content of oxygen comEby, L. T., Ibid., 25,1057 (1953). pounds. Furby, N. W., Ibid., 22,876 (1950). Gibbons, M. M., Public Works, 79, 38 (1948). As it appeared probable that the contamination was caused by Giles, R. N., Sewage and Ind. Wastes,24,1495 (1952). esters, the aromatic fraction was saponified with alcoholic potasGiles, R. N., Scheineman, F. W., Nicholson, C. T., and Austin, sium hydroxide and nonsaponifiables were recovered by extracR. J., Zbid.. 23, 281 (1951). tion with ether. The recovered extract, dissolved in benzene, Headington, C. E., et at., -4h-a~. CHEY.,25, 1681 (1953). Herd, M., Analyst, 78, 383 (1953). was filtered through a 70 X 9 mm. column of silica gel (to remove Hubbard, R. L.,and Stanfield, K. E., ANAL.CHEY.,20, 460 alcohols formed in the saponification). The infrared spectrum (1948). of the recovered eluate (Figure lo), after removal of solvent, still Karr, C., Weatherford, W. D., and Capell, R. G., Ibid., 26, 252 exhibited slight characteristics of oxygen groupings. I n other (1954). Lawrence, A. S. C., and Barby, D., Discussions Faraday SOC., respects it closely matched the standard aromatic spectrum, 7, 255 (1949). Figure 3. Melpolder, F. W., Warfield, C. W.,and Headington, C . E., The spectra of the aliphatic fraction and the purified aromatic ANAL.CHEM.,25, 1453 (1953). fraction thus support the conclusion that hydrocarbons resemMiddleton, F. M., Braus, H., and Ruchhoft, C. C., unpublished data, Robert A. Taft Sanitary Engineering Center files, 1951. bling those in refinery effluents are present in the lake water a t Muller, J. F., Gas-u. Wasserfach, 93, 205 (1952). this sampling point. The hydrocarbons, however, constitute a O'Donnell, Gordon, ANAL.CHEM.,23,894 (1951). minor portion of the organic substances recovered from the water. Ruchhoft, C. C., Middleton, F. M., Braus, Harry, and Rosen, A. A,, I n d . Eng. Chem., 46, 284 (1954). DISCUSSION OF RESULTS
The method described above is probably less sensitive than a discriminating sense of odor in the detection of petroleum refinery wastes in water. The combination of operations employed, however, yields recordable information independent of the subjective nature of odor judgments. The present method is based
Schuldiner, J. A., ANAL.CHEY.,23, 1676 (1951). Wedgewood, P. and Cooper R. L., Chemistry & Industry, 1951, 1066; Analyst, 78, 170 (1953). RECEIVED for review June 18, 1954. Accepted December 3, 1954. Presented before the Diviaion of Water, Sewage, and Sanitation Chemistry a t the 125th Meeting of the ANERICAX C"ahfIcAL SOCIETY, Kansas City, Mo., 1954.
