Abstract  A valid assessment of selective aerobic degradation on organic matter (OM) and its impact on OM-based proxies is vital to produce accurate environmental reconstructions. However, most studies investigating these effects suffer from inherent environmental heterogeneities. In this study, we used surface samples collected along two meter-scale transects and one longer transect in the northeastern Arabian Sea to constrain initial OM heterogeneity, in order to evaluate selective aerobic degradation on temperature, productivity and alteration indices at the sediment-water interface. All of the studied alteration indices, the higher plant alkane index, alcohol preservation index, and diol oxidation index, demonstrated that they are sensitive indicators for changes in the oxygen regime. Several export production indices, a cholesterol-based stanol/stenol index and dinoflagellate lipid- and cyst-based ratios, showed significant (more than 20%) change only over the lateral oxygen gradients. Therefore, these compounds do not exclusively reflect surface water productivity, but are significantly altered after deposition. Two of the proxies, glycerol dibiphytanyl glycerol tetraether-based TEX86 sea surface temperature indices and indices based on phytol, phytane and pristane, did not show any trends related to oxygen. Nevertheless, unrealistic sea surface temperatures were obtained after application of the TEX86, TEX86L, and TEX86H proxies. The phytol-based ratios were likely affected by the sedimentary production of pristane. Our results demonstrate the selective impact of aerobic organic matter degradation on the lipid and palynomorph composition of surface sediments along a short lateral oxygen gradient and suggest that some of the investigated proxies may be useful tracers of changing redox conditions at the sediment-water interface.

Abstract  Absorption spectra in the terahertz (THz) region between 10 and 400 cm(-1) were measured for fatty acids and their analogues at room temperature. Saturated fatty acids such as palmitic and stearic acids had some sharp peaks, while unsaturated fatty acids such as oleic, linoleic and linolenic acids had two distinct peaks at 247 and 328 cm(-1). These peaks apparently derived from the carboxylic group because oleyl alcohol had no distinct peak. The THz absorption spectra of fatty acids may be affected by the crystalline as well as the chemical structure. The THz absorption spectra of oleic acid esters depended on ester types, although all oleic acid esters had some peaks due to the ester group. THz absorbance of fatty acids positively correlated with concentration. Based on these results, THz spectrometry may be a good analytical method for the non-destructive qualitative and quantitative evaluation of fatty acids and their analogues.

Abstract  Alcohol ethoxylates (AEs) are an important group of nonionic surfactants. Commercial AEs consist of a mixture of several homologues of varying carbon chain length (Cx) and degree of ethoxylation (EOy). The major disposal route of AE is down the drain to municipal wastewater treatment plants that discharge into receiving surface waters. Sorption of AE homologues onto activated sludge and river water solids is an important factor in assessing exposure of AE in the environment. This study presents the experimental determination of sorption coefficients for a wide array of AE homologues including five alcohols under environmentally relevant conditions and combines these data with literature data to generate a predictive model for the sorption of AEs in the environment. These results demonstrate that sorption can be effectively modeled using a log Kd vs. Cx and EOy predictive equation having the form log Kd = 0.331C - 0.00897EO - 1.126(R2 = 0.64).

Abstract  The sterol distributions in the steryl chlorin esters (SCEs) from three marine and two lacustrine sediments have been compared with the free sterols and known water column sterol distributions. The comparison provides further evidence that the SCE sterol distributions are more representative of the original phytoplanktonic sterol distribution than are the free sterol distributions. This is most clearly seen in the relative abundance of C-26 sterols and 4-methyl sterols, and in the stanol/stenol ratios. It appears that in general the SCE sterols are less susceptible to selective biodegradation than the free sterols. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

Abstract  Industrially, the most important alcohols are methanol, ethanol, 1‐propanol, 1‐butanol, 2‐methyl‐1‐propanol (isobutyl alcohol), the plasticizer alcohols (C6–C11), and the fatty alcohols (C12–C18), used for detergents. They are prepared mainly from synthesis gas alone (methanol), from olefins via the oxo synthesis, or by the Ziegler process. Apart from the applications mentioned above, alcohols are used as solvents and diluents for paints (mainly C1–C6 alcohols) 1, as intermediates in the manufacture of esters and a whole range of organic compounds, as flotation agents, as lubricants, and as fuel or fuel additives, e.g., methanol, ethanol, tert‐butyl alcohol. For industrial purposes, isomeric mixtures often are preferred because the pure alcohols are too expensive. Moreover, mixtures of alcohols with differing numbers of carbon atoms can be advantageous for certain purposes. Therefore, the amounts of alcohol mixtures available on the market are similar to the quantities of the pure, individual alcohols.

Abstract  Repeat applications of an artificial monolayer to the interfacial boundary layer of large agricultural water storages during periods of high evaporative demand remains the most commercially feasible water conservation strategy. However, the interfacial boundary layer (or microlayer) is ecologically distinct from subsurface water, and repeat monolayer applications may adversely affect microlayer processes. In this study, the natural cleansing mechanisms operating within the microlayer were investigated to compare the biodegradability of two fatty alcohol (C16OH and C18OH) and one glycol ether (C18E1) monolayer compound. The C16OH and C18OH compounds were more susceptible to microbial degradation, but the C18E1 compound was most susceptible to indirect photodegradation. On clean water the surface pressure and evaporation reduction achieved with a compressed C18E1 monolayer was superior to the C18OH monolayer, but on brown water the surface pressure dropped rapidly. These results suggest artificial monolayers are readily degraded by the synergy between photo and microbial degradation. The residence time of C18OH and C18E1 monolayers on clear water is sufficient for cost-effective water conservation. However, the susceptibility of C18E1 to photodegradation indicates the application of this monolayer to brown water may not be cost-effective.

Abstract  Near surface sediments from an abyssal northeast Atlantic site were sectioned using a newly designed Precision Core Extruder (PCE). Downcore profiles of excess Pb-210 and sterols showed pronounced millimeter-scale variability reflecting specific degradation and bioturbation processes. Excess Pb-210 and sterol concentrations decreased sharply in the uppermost 5 mm, and pronounced subsurface maxima were present. Stanol/stenol ratios, and the relative abundance of cholesterol, increased below 10 mm, indicating biodegradation involving Delta(5) double bond hydrogenation, C-24 dealkylation and/or de novo synthesis. Sterol profiles indicate that early diagenesis of labile compounds is dominated by processes operating near the sediment/water interface, and that the penetration of labile material into oxic sediments is largely controlled by advective processes, associated with infaunal feeding rather than diffusive-like mixing.

Abstract  SIDS INITIAL ASSESSMENT: There is need for further work. SHORT SUMMARY OF THE REASONS WHICH SUPPORT THE RECOMMENDATION: The substance is firmly bound to sediments, and therefore anaerobic biodegradation can be an important factor. A 21-day test in daphnids indicated that the substance may be toxic at a range of between 1 and 3mg/l. FURTHER WORK RECOMMENDED: Determination of anaerobic biodegradability. Depending on the results of this test, it may be considered whether or not long-term fish toxicity testing is required.

Abstract  The examination of a number of potential and currently used carrier fluids for invert emulsion drilling fluids in the ECETOC screening test revealed clear differences with respect to their easy anaerobic biodegradability. Fatty acid- and alcohol-based ester oils exhibited excellent anaerobic degradation to the gaseous final end products of the methanogenic degradation pathway, methane and carbon dioxide. Mineral oils, dialkyl ethers, alpha-olefins, polyalphaolefins, linear alkylbenzenes and an acetal-derivative were not or only slowly degraded. Although the poor degradation results obtained in the stringent ECETOC screening test may not be regarded as final proof of anaerobic recalcitrance, nevertheless, these results were found to be in line with the present understanding of the structural requirements for anaerobic biodegradability of chemicals. The validity of the conclusions drawn is corroborated by published results on the anaerobic biodegradation behaviour of ester oils, mineral oils and alkylbenzenes in marine sediments.

Abstract  We investigated the influence of biological and physical seabed disturbance on the degradation of bulk organic matter and source specific lipid biomarker compounds by measuring downcore changes in bulk elemental composition, bulk stable isotopic (delta(13)C and delta(15)N) signatures, and lipid biomarker compounds in sediment cores collected from two sites in the York River, a subestuary of the Chesapeake Bay, USA. One site (LY) is influenced by biological mixing (bioturbation), restricted to the upper 15-20 cm, while the other site (POD) experiences intense, episodic physical mixing events that penetrate 50-100 cm into the sediment. We utilized a suite of auxiliary measurements to constrain the sources of organic matter, depositional environments, and general ages of the cores. Diagenetic modeling of total organic carbon and total nitrogen in sediments yielded higher apparent rate constants for POD than LY suggesting that the physical mixing regime promotes enhanced degradation of bulk organic matter. Apparent rate constants for select lipids representing distinct sources of organic matter were also higher at POD than LY for all but the most labile (i.e., diatom-derived fatty acids) biomarkers. Differences in stanol/stenol ratios also supported enhanced diagenesis of stenols at POD. The source-specific biomarkers, while useful in qualitatively identifying the sources of sedimentary organic matter, likely do not represent the full spectrum of its reactivity. However, based on our results, we hypothesize that the intense sediment disturbance at POD promotes degradation of more recalcitrant organic material, due to prolonged exposure to oxygen and other electron acceptors (e.g., NO3-, Mn and Fe oxides). In contrast, the degradation of more labile constituents is equally facilitated by biological and physical disturbance. Copyright (C) 2004 Elsevier Ltd.

Abstract  A standardized, feasible test system for assessing the environmental behavior of chemicals in ecotoxicological terms and for setting up priority lists was described earlier. 14C chemicals were used in environmentally relevant concentrations. The bioaccumulation potential of chemicals was determined from tests with algae and fish; mammalian retention and elimination were investigated in a test with rats. Information about biodegradability, metabolism, accumulation, and bound residues was provided by the activated sludge test, while the possibility of photomineralization of the organic compounds was studied by irradiation with uv light of wavelength above 290 nm. The presentation of the data is by ranking in tables: they are either ranked in order of decreasing accumulation in the algae, fish, rat, and activated sludge tests (lipophilic substances such as hexachlorobenzene, chlorinated biphenyls, aldrin, etc., displaying the highest accumulation, are on top of the lists); or they are ranked in order of increasing degradability in the activated sludge and photomineralization tests (the most persistent chemicals thus again are on the top of the list). The data obtained from the accumulation tests are correlated with respective physicochemical properties of the chemicals and the results of the tests are compared with one another for ecotoxicological profile assessment.

Abstract  A test system is described for assessing the mineralization of 14C-radiolabeled compounds to carbon dioxide (CO2) and methane (CH4) under anaerobic conditions. Environmentally realistic concentrations of test chemicals were incubated with anaerobic digester sludge in sealed vessels at 35 °C. The headspace of these vessels was continuously purged with nitrogen, which was passed through a series of potassium hydroxide (KOH) scrubbers to trap 14CO2. This effluent gas was mixed with oxygen and passed through a combustion tube containing cupric oxide at 800 °C to convert 14CH4 to 14CO2, which was subsequently trapped in a second series of KOH traps. Trapping efficiency was 97.1 ± 5% for 14CO2 and 108 ± 13% for 14CH4. The system was used to evaluate the mineralization of several organic chemicals including glucose, palmitic acid, hexadecanol, and two surfactants, alkyl ethoxylate sulfate (AES) and alkyl sulfate (AS), in anaerobic digester sludge. Total yields of 14CH4 and 14CO2 from these compounds exceeded 80%, and the total mass balances generally exceeded 95%. Mineralization of hexadecanol was described by a simple first-order production equation, while that of the other compounds was best described by a three-half-order model. This system provided excellent recovery of radioactive gases and consequently excellent mass balances. Given the reproduction of in situ condition and the realistic ratio of test material to biomass, the test system also generated relevant kinetic data. It, therefore, has application for demonstrating the significance of biodegradation as a removal mechanism during anaerobic digestion as well as determining the completeness of anaerobic biodegradation.

Abstract  SIDS dossiers already existed for 1-Dodecanol (CAS 112-53-8) and 1-Octadecanol (CAS 112-92-5) (published in 1998 and 1995 respectively); the present document updates and extends the earlier ones; brings in new information, and therefore replaces it. No conclusions drawn in the earlier review are amended. Available data for these substances are compiled in SIDS dossiers related to each CAS number. The reliability of each data point has been considered during this period of review, in accordance with the guidance of the Fraunhofer Institut für Toxikologie und Aerosolforschung. The following standard reliability codes, defined by Klimisch et al. (1997)1, apply, in accordance with the SIDS guidance: (1) Valid without restriction (2) Valid with restrictions (3) Invalid (4) Not assignable. Results considered to be Invalid are not used in the discussions or conclusions in this report. However, results which are of Non-assignable reliability may be fully valid, although insufficient details were available to be sure of this; therefore reliability (4) results are used in this report. The reliability code of each data point is given. Key studies are flagged in the SIDS dossiers. These are studies with the highest reliability/adequacy. If several studies showed comparable reliability/ adequacy, the study with the lowest LC/LD/EC50 or NOEC/ NOAEL has been indicated as the key study. For some endpoints, fully reliable results are not available and it has been necessary to use a weight of evidence including results of studies of non-assignable reliability. In such cases the results are identified as key studies as they are of high importance to the data set. For transparency, some study summaries in the SIDS dossier have been transferred from the previously published version of IUCLID or from the previous SIDS submission. In some cases, it has not been possible to retrieve the original literature/study reports using the reported citation or as a result of literature searching. In some cases, change of business ownership meant that internal study reports cited in previous summaries could not be accessed. In some other cases, e.g. certain non-SIDS endpoints, and in areas where a very large amount of literature has been published, it was not considered necessary to pursue all individual published sources due to weight of evidence of more reliable results. In all cases, reliability (4) applies, because the original documentation has not been reviewed in the development of the dossier. Such results are clearly identified in the SIDS dossier and more details are given therein.

Abstract  Fatty alcohols and their derivatives are popular additives in shampoos, cosmetics, paints, lubricants and other functional fluids, whose films are exposed to the environment. Often these films degrade due to oxidative, thermal, catalytic and other stress factors, producing volatile emissions. Decomposition of fatty materials is rarely viewed as a significant contributor to vapour losses, however, it cannot be assumed that fatty alcohols are completely non-volatile. In this study, oxidative degradation of thin films of oleyl and stearyl alcohols was investigated on the steel surface. Tests at 90 degrees C showed that within several hours significant portions of these alcohols were lost to volatile emissions. Initially the absolute evaporation rates did not depend on the film thickness and appeared quite similar for both alcohols. In later stages, the evaporation rate of thinner films went down due to the formation of oxidative polymers and functional group oxidation. Acidity of oleyl alcohol increased much more rapidly than that of stearyl. After long-term degradation oleyl alcohol produced gel-like solids, while films of stearyl alcohol began to retain a liquid state at room temperature. Since the volatile emissions amounted to more than 60%, the decomposition products in final applications should be investigated in more detail when stearyl or oleyl alcohols are used as major constituents in commercial liquids.

Abstract  The recently developed technique of aerosol chemical ionization mass spectrometry is used to study the reaction of ozone with particles consisting of unsaturated organic molecules, including oleic acid, linoleic acid, oleyl alcohol, and 1-octadecene. The reactive uptake coefficients, gamma, for polydisperse aerosols with mean diameters of 800 nm are determined from the rates of loss of the particle species to be (7.5 +/- 1.2) x 10(-4) for oleic acid, (1.1 +/- 0.2) x 10(-3) for linoleic acid, (7.5 +/- 1.3) x 10(-4) for oleyl alcohol, and (2.4 +/- 0.4) x 10(-4) for 1-octadecene. The ozonolysis products of oleic acid particles are studied in detail with simultaneous detection of the four primary products: nonanal, nonanoic acid, 9-oxononanoic acid, and azelaic acid. All four products are found to exist in the reacted particles, though nonanal is also detected in the gas phase indicating that it partially evaporates. The yield of azelaic acid is determined to be 0.12 +/- 0.04, and the yields of nonanal and 9-oxononanoic acid are found to be larger than the yields of the other products suggesting the existence of secondary reactions involving the Criegee intermediates. A fifth product, 9-oxooctadecanoic acid, is detected with a small yield (similar to0.02) and is believed to result from different secondary reactions. Implications of these results for the alteration of chemical and physical properties of aerosols as they are aged in the atmosphere are discussed.

Abstract  Fatty alcohols are aliphatic alcohols with chain lengths between C6 and C22: CH3(CH2)NCH2OH(n= 4-20) They are predominantly linear and monohydric, and can be saturated or have one or more double bonds. Alcohols with a carbon chain lengthabove C22 are referred to as wax alcohols. Diols whose chain length exceeds C8 are regarded as substituted fatty alcohols. The character of the fatty alcohols (primary or secondary, linear or branched-chain, saturated or unsaturated) is determined by the manufacturing process and the raw materials used. Natural products, such as fats, oils, and waxes, and the Ziegler alcohol process provide linear, primary, and even-numbered alcohols; those obtained from natural sources may be unsaturated. In contrast, the oxo process yields 20 – 60 % branched fatty alcohols, and also some odd-numbered ones. Guerbet dimerization results in a-branched, primary alcohols, whereas Bashkirov oxidation yields secondary alcohols. Depending on the raw materials used, fatty alcohols are classified as natural or synthetic. Natural fatty alcohols are based on renewable resources such as fats, oils, and waxes of plant or animal origin, whereas synthetic fatty alcohols are produced from petrochemicals such as olefins and paraffins. Up to 1930, when catalytic highpressure hydrogenation was developed ADKINS and FOLKER [7], NORMAN [8], SCHRAUTH [9], and SCHMIDT [10], the manufacture of fatty alcohols was based almost exclusively on the splitting of sperm oil. By 1962, the world production capacity from natural raw materials had grown to ca. 200 000 t/a. New processes utilizing petrochemical raw materials, e.g., the Ziegler alcohol process, the SHOP process, the oxo process, and the construction of additional plants for highpressure hydrogenation of natural raw materials, allowed a further increase. In 2005, the world nameplate production capacity of fatty alcohols was estimated to be 2.5 106 t/a, being nearly equally based on natural and petrochemical feedstocks. This ratio will change because 600 000 – 700 000 t/a of additional production capacity based on natural feedstocks will come on stream by 2008. Production and consumption were estimated to amount to only 80 % or less of capacity. Fatty alcohols and their derivatives are used in polymers, surfactants, oil additives, and cosmetics and have many specialty uses.

Abstract  Absorption of hydrophobic volatile organic compounds (VOCs): dimethylsulfide (DMS), dimethyldisulfide (DMDS) and toluene, in organic solvents: di-(2-ethyl)hexyladipate (DEHA), n-hexadecane, oleyl alcohol and PEG 400, was studied. In order to characterise the absorption capacity of various VOC/solvent systems, the Henry's constant (H) was determined. DMS was found to be the least absorbable in all the selected solvents. Amongst these solvents, DEHA was found to be the most efficient to absorb the considered VOCs. The effect of water addition to the considered solvents (emulsions) on the Henry's constants was examined and confirmed a decreasing VOC absorption for an increasing amount of water in solvent. Finally, to quantify the process rapidity, the absorption rate (N) and the overall liquid mass transfer coefficient (KLa) were measured for some selected couples VOC/solvent and revealed a superior efficiency of DEHA compared to other solvents in trapping DMS, DMDS and toluene.

Abstract  To study the mechanism of non-glyceride lipids transport and metabolism in fish, the fate of dietary fatty alcohols and wax esters were investigated by force-feeding [1-14C] oleyl alcohol and [1-4C] oleyl pahmitate to carp. When [1-14C] oleyl alcohol was fed, the total radioactivities in plasma lipoproteins increased gradually, the maximum being around 28h. When [1-14C] oleyl palmitate was given, it was hydrolyzed largely in the intestinal lumen and the total radioactivities in plasma lipoproteins increased with the maximum being around 12h. In both cases, almost all the radioactivities were found in HDL fraction as the forms of mainly triglyceride (TG) and phosphatidylcholine (PC). After 72h of feeding, the radioactivities from [1-14C] oleyl alcohol and [1-14C] oleyl palmitate were found mostly in muscle, intestine, hepatopancreas and gill as mainly in the forms of TG or PC. Tn either cases, a little amount of radioactivity was detected in the class of wax ester or fatty alcohol in each tissue. The dietary fatty alcohol and alcohol moiety of wax ester were largely oxidized to the corresponding acids in the intestinal tissue, which then behaved as in the case of dietary acid, and some were reesterified to form wax esters. Then, most of them were transported as TG and PC with HDL in plasma. Finally, it is suggested that the fatty alcohol in various tissues of carp, which seems to be a substrate of acyl CoA: alcohol acyltransferase, is one of the most important key precursor to form wax esters. Moreover the circulating lecithin: alcohol acyltransferase (LAAT) in plasma also seems to relate to wax ester synthesis.

Abstract  The wastewater from a small speciality chemicals manufacturing plant located on the Pawtuxet River (Rhode Island, USA) has contaminated the water and sediment of that river, the Pawtuxet Cove, the Providence River, and (to a lesser extent) the Narragansett Bay. Since the compounds found in this system cover a wide range of functionalities, polarities, and water solubilities, a detailed study of this system has allowed us to assess the environmental behavior of several compound types in one aquatic system. We find that the aqueous concentrations of the various compounds follow the rules of simple dilution and that those compounds with the highest octanol-water partition coefficients (log P) are strongly associated with the particulate matter in the water and are found in the sediment at the greatest distance from the plant. The sediment concentrations (C) of a given compound can be predicted from its log P value and from its concentration in the wastewater (Co) by log (Cq/C) = bo + h2(dist/log P) where dist is the distance of the sediment sample from the plant and b0 and t>2 are constants fitted to the data.