S-containing Organic Compounds Research Articles

Different impacts of natural and anthropogenic factors on dissolved organic matter chemistry in coastal rivers: Implications for water management

The chemical composition of dissolved organic matter (DOM) exerts significant influence on aquatic energy dynamics, pollutant transportation, and carbon storage, thereby playing pivotal roles in the local water quality and regional-global biogeochemical cycling. However, the effects of natural climate change and local human activities on watershed characteristics and in-river processes have led to uncertainties regarding their contributions to DOM chemistry in coastal rivers, creating challenges for effective water management and the study of organic matter cycling. In this investigation, we employed a combination of stable isotopic analysis, optical techniques, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) to elucidate the sources, optical properties, and molecular composition of DOM in three South China coastal rivers. Our results suggest that terrestrial DOM entering the three rivers through natural or anthropogenic pathways is gradually diluted by in situ primary production as it moves downstream, ultimately being influenced by seawater intrusion near the estuary. Additionally, terrestrial processes influenced by temperature likely govern DOC concentration, while seawater intrusion promotes the natural production of S-containing organic compounds. In contrast, human-altered landcover significantly impacts DOM molecular composition. Increased water areas lead to the enrichment of lignins with high disinfection byproduct formation potential, and agricultural residue burning appears to be the dominant source of pyrogenic DOM in these coastal rivers. Our distinct results suggest that the development of specific water management plans that consider the combined effects of temperature, seawater intrusion, landcover changes, and agricultural practices will be essential to ensure sustainable water resource.

Release and evolution mechanism of oxygen-containing compounds and aromatics during the co-pyrolysis of waste tire and bamboo sawdust/rice husk by Py-GC/MS

Using the measurement technique pyrolysis gas-chromatography/mass spectrometry, the release characteristics of oxygen-containing compounds and aromatics during the pyrolysis of waste tire (WT) and the co-pyrolysis of WT and bamboo sawdust (BS)/rice hull (RH) were analyzed at low temperature (350 °C), medium temperature (550 °C) and high temperature (750 °C). The oxygen-containing compounds from the WT pyrolysis contained acids, phenols, alcohols, esters, peroxides and oxygen-containing heterocycles. Especially, the acids such as palmitic acid and stearic acid presented the highest proportion of 8.68% at 350 °C. The oxygen-containing compounds proportion showed a sharply decreasing trend with the increase of temperature. The aromatics proportion was extremely low at 350 °C and 550 °C, while aromatics proportion was as high as 44.64%, including benzene, alkyl substituted benzene, indene, naphthalene and alkyl substituted naphthalene at 750 °C. The proportion of benzene, toluene and xylene was 17.05%, and that of naphthalene and its derivatives was 7.86%. After adding BS or RH, the aromatics proportion increased at 550 °C. The aromatics proportion decreased by more than 16% with the addition of BS, while the aromatics proportion increased with the addition of RH, such as benzene, indene and naphthalene derivatives. It was also found that the relative oxygen-containing components and aromatics proportion showed an opposite trend along the temperature. At 750 °C, oxygen-containing compounds could be converted into aromatics through a series of free radical reactions. For the WT pyrolysis, N-containing organic compounds proportion in gas product as the temperature increased. While the S-containing organic compounds were released into gas phase only at 550 °C. Adding BS could reduce the formation of N- and S- containing organic compounds. However, adding RH inhabited the N-containing organic compounds formation only at 350 °C. Adding RH also inhabited the formation of S-containing organic compounds formation, while this while this positive effect was weaker than that of adding BS. Finally, according to the obtained results from Py-GC/MS at different temperatures, it was found that the active oxygen-containing free radicals released from BS could promote the chain breaking of rubber components and release hydrogen free radicals. With the aggravation of hydrogen transfer reaction, the oxygen-containing organic compounds were continuously transformed into hydrocarbon products. Co-pyrolysis promoted decarboxylation and decarbonylation reaction, resulting in the formation of H2 and free radicals, thus promoting the generation of alicyclic hydrocarbons, aliphatic chain hydrocarbons and benzene. This work provided the in-depth comparison and investigation the waste tire pyrolysis and products evolution.

You Exude What You Eat: How Carbon-, Nitrogen-, and Sulfur-Rich Organic Substrates Shape Microbial Community Composition and the Dissolved Organic Matter Pool.

Phytoplankton is the major source of labile organic matter in the sunlit ocean, and they are therefore key players in most biogeochemical cycles. However, studies examining the heterotrophic bacterial cycling of specific phytoplankton-derived nitrogen (N)- and sulfur (S)-containing organic compounds are currently lacking at the molecular level. Therefore, the present study investigated how the addition of N-containing (glycine betaine [GBT]) and S-containing (dimethylsulfoniopropionate [DMSP]) organic compounds, as well as glucose, influenced the microbial production of new organic molecules and the microbial community composition. The chemical composition of microbial-produced dissolved organic matter (DOM) was analyzed by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) demonstrating that CHO-, CHON-, and CHOS-containing molecules were enriched in the glucose, GBT, and DMSP experiments, respectively. High-throughput sequencing showed that Alteromonadales was the dominant group in the glucose, while Rhodobacterales was the most abundant group in both the GBT and DMSP experiments. Cooccurrence network analysis furthermore indicated more complex linkages between the microbial community and organic molecules in the GBT compared with the other two experiments. Our results shed light on how different microbial communities respond to distinct organic compounds and mediate the cycling of ecologically relevant compounds. IMPORTANCE Nitrogen (N)- and sulfur (S)-containing compounds are normally considered part of the labile organic matter pool that fuels heterotrophic bacterial activity in the ocean. Both glycine betaine (GBT) and dimethylsulfoniopropionate (DMSP) are representative N- and S-containing organic compounds, respectively, that are important phytoplankton cellular compounds. The present study therefore examined how the microbial community and the organic matter they produce are influenced by the addition of carbohydrate-containing (glucose), N-containing (GBT), and S-containing (DMSP) organic compounds. The results demonstrate that when these carbon-, N-, and S-rich compounds are added separately, the organic molecules produced by the bacteria growing on them are enriched in the same elements. Similarly, the microbial community composition was also distinct when different compounds were added as the substrate. Overall, this study demonstrates how the microbial communities metabolize and transform different substrates thereby, expanding our understanding of the complexity of links between microbes and substrates in the ocean.

Need for Determining the Effects of Sulphur Fertilization on the Amounts of Organic Sulphur Compounds in Plant Foods

A large number of field trials are being conducted in India and across the globe on the yield response and uptake of sulphur (S) in a number of crops and most results show a good yield response. However, none of the studies bring out the effect of S fertilization on S containing amino acids viz. cysteine, methionine and vitamin like Thiamine, which are essential for human life and are to be obtained only from plant foods. It is due to lack of awareness and also poor infrastructures in terms of biochemical analysis of the agricultural produce in most of the developing countries including India. Therefore, there is an urgent need to establish food quality analysis laboratories in the leading institutes of the country for initiating analysis of plant foods for S-containing organic compounds

Sorbents based on transition metal salts for the retention of low molecular weight N-, O- and S-containing organic compounds from the air flow

Regularities for the retention of low molecular weight N-, O- and S-containing organic compounds from the air flow have been established for the sorbents based on transition metal (NiII, CoII, and CuII) chlorides. The performance of developed sorbents was compared with that of some commercially available materials.

Cu(I)-Catalyzed Acetylene Hydration Using S-Containing Organic Compounds as Ligands

Several S-containing organic compounds were used as ligands for Cu(I)-catalyzed acetylene hydration under mercury free condition. The results show that the minimum selectivity for acetaldehyde is significantly improved from 3.61 to 87.56%, while the minimum conversion of C2H2 is also enhanced from 14.45 to 34.92%, owing to the addition of mercaptosuccinic acid. The possible reasons for the improvement in acetaldehyde selectivity were studied by the density functional theory calculations. The results show that the addition of S-containing organic compounds improves the coordinating ability of Cu complex I with C2H2.

New insight into the chemical structures of Huadian kerogen with supercritical ethanolysis: Cleavage of weak bonds to small molecular compounds

Oil shale is a potential alternative fossil energy source. The chemical structure of oil shale kerogen is the basis of its application, presently for retorting to yield shale oil and gas. Supercritical ethanolysis is a kind of chemical extraction which can effectively depolymerize organic matter like coal and lignin through breaking some weak bonds. In this work, new insights into weak bonds (including O-containing, N-containing and S-containing functional groups) of the chemical structures of Huadian kerogen (HDK) were obtained with supercritical ethanolysis, and the resulted products, small molecular compounds (SMCs), were identified. It was found that, after ethanolysis at 375 °C, 87.4% of HDK was converted by breaking the weak bonds to SMCs, including aliphatic acid esters, aliphatic acids, alkanes, alcohols, aromatics, N-containing organic compounds (NCOs), and S-containing organic compounds (SCOs). In the SMCs, there are 52.0% aliphatic acid esters and aliphatic acids with carbon numbers from 4 to 26, 11.4% alkanes with carbon numbers from 14 to 22, 19.1% aromatic compounds with single-ring and double-ring aromatic clusters, 5.4% alcohols, 5.0% NOCs, 1.9% SCOs, and 5.4% biomarkers. FTIR and 13C NMR were used to characterize the changes of HDK and its residues, which further demonstrate that the SMCs are present and connected with weak bonds to solid aromatic clusters insoluble in ethanol. During the pyrolysis of oil shale, these weak bonds are first broken and the above SMCs are produced in molecular or radical states, which are the most compounds from the primary reactions and readily undergo the second reactions to yield oil and gas.

Depth rather than microrelief controls microbial biomass and kinetics of C-, N-, P- and S-cycle enzymes in peatland

The formation of microrelief forms in peatlands - elevated and dry hummocks, depressed wet hollows and intermediate lawns - is controlled by the interaction of water table, nutrient availability and dominant plant communities. This affects the composition and activity of various functional groups of microorganisms. With depth, the change in peat quality from less to more highly processed organic material additionally regulates microbial activity. We hypothesized that microbial biomass and enzyme activities are driven by aeration and by peat quality and therefore (i) they increase from hollows (water saturated/anaerobic) through lawns (intermediate) to hummocks (aerobic) in the top peat and ii) they decrease with depth due to increasing distance from fresh plant-derived inputs and lower oxygen availability. These hypotheses were tested for enzymes catalysing the decomposition of C-, N-, P- and S-containing organic compounds in peat of the three microform types at three depths (15, 50 and 200 cm). Microbial biomass and peat chemical characteristics were compared with enzyme kinetic parameters, i.e. maximal potential activity (Vmax) and the Michaelis constant (Km).Microbial biomass carbon (MBC) and Vmax of β-glucosidase and N-acetyl glucosaminidase increased by 30–70% from hummocks and lawns to hollows in the top 15 cm, contradicting the hypothesis. Similarly, Km and the catalytic efficiency of enzymes (Ka = Vmax/Km) were best related to MBC distribution and not to the aeration gradient. With depth, Vmax of β-glucosidase, xylosidase and leucine aminopeptidase followed the hypothesized pattern in hollows. In contrast, MBC was 1.3–4 times higher at 50 cm, followed by successively lower contents at 15 and 200 cm in all microforms. The same depth pattern characterized the Vmax distribution of 6 out of 8 enzymes. Phosphatase activity decreased from drier hummock to wetter hollows and the higher activity throughout the peat profile suggested a high microbial demand for P. Enzyme activities and catalytic efficiency in peat were closely linked to the distribution of microbial biomass with depth, which in turn was best explained by P content. From the ecological perspective, these results clearly show that peat decomposition will be accelerated when microbial activity is stimulated e.g. by increased P availability.

Rapid screening of pharmaceutical substances for the total content of F-, Cl-, Br-, and S-containing organic compounds

A fast direct method for determination of the total content of F-, Cl-, Br-, and S-containing organic compounds in pharmaceutical substances is developed. The method is based on direct oxidative hightemperature conversion and analysis of the whole absorbate volume by ion chromatography. Detection limits are 2 × 10–6–4 × 10–6% depending on the element at a sample mass of 1 mg.

The tribological behaviors of disulfide-type triazine derivatives as additives in biodegradable lithium grease

Two novel disulfide-type triazine derivatives, 6,6'-disulfanediylbis(4-(dibutylamino)-1,3,5-triazine-2-thiol) (coded DTBT) and 6,6'-disulfanediylbis(4-(bis(2-ethylhexyl)amino)-1,3,5-triazine-2-thiol) (coded DTOT), were prepared. A four-ball tester was used to evaluate their tribological performances as anti-wear and extreme-pressure additives in biodegradable lithium grease. The results show that the disulfide-type triazine derivatives possess good friction-reducing properties and excellent anti-wear, extreme-pressure capacities. For further understanding of their tribological behaviors, X-ray photoelectron spectroscopy and scanning electron microscopy are adopted to analyze the tribofilms generated from these additives in biodegradable lithium grease. The results of X-ray photoelectron spectroscopy analysis illustrate that the prepared compounds as additives in biodegradable lithium grease forms a protective film containing FeS, FeS2 (or S-containing organic compounds), Fe2(SO4)3, FeSO4, FeO (or Fe3O4), and N-containing organic compounds on the metal surface during the sliding process.

Antiwear Properties and Tribochemical Action Mechanisms of Three S-Containing Triazine Derivatives as Additives in Rapeseed Oil

The antiwear properties of three S-containing triazine derivatives with different active groups, referred to as HOT, HOMA, and TOMA, as additives in rapeseed oil (RSO) were evaluated using a four-ball friction and wear tester. The morphologies of the worn surfaces of the steel balls were observed using a scanning electron microscope (SEM). The tribochemical action mechanisms of the S-containing triazine derivatives in rapeseed oil were investigated by means of X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure spectroscopy (XANES). It was found that all three S-containing triazine compounds added in the rapeseed oil at a proper concentration showed rather good antiwear behavior. XPS and XANES analytical results showed that the tribofilms from the worn surfaces of the steel balls lubricated with RSO-1.2 wt% HOMA and the discs lubricated with RSO-3.0 wt% HOMA were mainly composed of some adsorbed N-, O-, and S-containing organic compounds, along with appreciable oxidized S products such as sulphite and sulphate. In contrast, the films from RSO-1.2 wt% TOMA showed a large concentration of FeS and FeS2, with a smaller amount of oxidized S products. The large difference in the chemical compositions of the tribofilms of RSO-HOMA and RSO-TOMA could be closely related to the differences in their active element content and bond types.

New heterogeneous catalysts for mild oxidation of S-containing organic compounds

Abstract Titanosilicate (1.5 wt.% Ti) with very well-ordered MCM-48 mesostructure was synthesized using fumed silica and titanium isopropoxide as silicon and titanium sources, respectively. It was successfully used as a new catalyst for the mild oxidation of S-containing organic compounds with H2O2. Recent results obtained by our group in the sulfoxidation reaction using W-, V- and Mo-containing layered double hydroxides as catalysts are also reviewed in this paper. The catalytic materials were characterized by appropriate techniques such as X-ray diffraction, N2 adsorption, thermal gravimetric analysis, diffuse reflectance ultraviolet spectroscopy in order to evaluate their textural properties and the nature of the metal species.

Bacterial DMSP metabolism during the senescence of the spring diatom bloom in the Northwest Atlantic

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 369:1-11 (2008) - DOI: https://doi.org/10.3354/meps07664 FEATURE ARTICLE Bacterial DMSP metabolism during the senescence of the spring diatom bloom in the Northwest Atlantic Anissa Merzouk1,*, Maurice Levasseur2, Michael Scarratt3, Sonia Michaud3, Martine Lizotte2, Richard B. Rivkin4, Ronald P. Kiene5 1University of British Columbia, Earth and Ocean Sciences/Oceanography, 1461-6270 University Boulevard, Vancouver, British Columbia V6T 1Z4, Canada 2Université Laval, Département de biologie (Québec-Océan), Pavillon Alexandre-Vachon, Quebec, Quebec G1K 7P4, Canada 3Fisheries and Oceans Canada, Maurice Lamontagne Institute, 850 Route de la mer, Mont-Joli, Quebec G5H 3Z4, Canada 4Ocean Sciences Centre, Memorial University of Newfoundland, St. John’s, Newfoundland A1C 5S7, Canada 5University of South Alabama, Department of Marine Sciences, Mobile, Alabama 36688, USA *Email: amerzouk@eos.ubc.ca ABSTRACT: The impact of the decline of the vernal bloom on the bacterial metabolism of dimethylsulfoniopropionate (DMSP), the precursor of dimethylsulfide (DMS), was investigated during a 7 d Lagrangian study conducted in the Northwest Atlantic in spring 2003. Daily variations in bacterial leucine incorporation, dissolved DMSP (DMSPd) uptake and DMS production rates were measured in the surface mixed layer (SML) and in the deep chlorophyll a maximum (DCM) that formed as the bloom collapsed. Seawater samples were amended with 35S-DMSPd, and the products of bacterial DMSPd degradation were measured during 3 h on-board incubations. The gradual decrease in phytoplankton biomass and diatom abundance measured in the SML was accompanied by a sharp doubling of the bacterial abundance and a peak in leucine incorporation rate on Day 2, suggesting that bacteria responded to a transient pulse in dissolved organic matter. Bacterial DMSPd uptake and DMS production were highest on Days 1 and 2 (1.2 and 0.10 nmol l-1 h-1, respectively), but rapidly decreased by Day 3, suggesting that DMSPd was becoming a less important substrate for the growing bacterial assemblage as other substrates became available. Bacterial DMSPd uptake and DMS production rates were also low in the DCM despite very high DMS yields (40 to 50%), showing that neither the decline of the diatom spring bloom in the SML nor the accumulation of cells in the DCM resulted in a stimulation of bacterial DMSP metabolism or accumulation of DMS. The present study provides new field evidence for the potential uncoupling between bacterial production and DMS dynamics likely due to variations in the availability of other S-containing organic compounds released during the decay of phytoplankton blooms. KEY WORDS: DMSP cycling · Bacterial metabolism · Bloom senescence · Northwest Atlantic Ocean Full text in pdf format Information about this Feature Article NextCite this article as: Merzouk A, Levasseur M, Scarratt M, Michaud S, Lizotte M, Rivkin RB, Kiene RP (2008) Bacterial DMSP metabolism during the senescence of the spring diatom bloom in the Northwest Atlantic. Mar Ecol Prog Ser 369:1-11. https://doi.org/10.3354/meps07664Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 369. Online publication date: October 13, 2008 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2008 Inter-Research.

Tribological behaviour of three S-containing triazine derivatives and their synergetic effect with zinc dialkyldithiophosphate as additives

The antiwear properties of three S-containing triazine derivatives with different active groups, referred to as TOSS, HOT, and HOMA, as additives in mineral oil, were evaluated using a four-ball friction and wear tester. Their thermal stabilities were investigated and the results suggest that all the synthesized compounds have good thermal stability. It was found that all the three S-containing triazine compounds added to the mineral oil showed rather good tribological behaviour, and the synergism between HOMA and zinc dialkyldithiophosphate (ZDDP) is better than that between ZDDP and HOT/TOSS. The worn surfaces of the steel balls were observed using X-ray photoelectron spectroscope. It is supposed that the synthetic additives adsorb and react with the steel surface during the process and thus generate a surface protective film composed of sulphate, iron oxide, and N-, O-, and S-containing organic compounds, which accounts for the better tribological behaviours of the base stock containing the synthetic additives when compared with the base stock alone.

Wet oxidation of TNT red water and bacterial toxicity of treated waste

This laboratory study determined the composition of the off-gas after wet oxidation (WO) of trinitrotoluene (TNT) red water, and monitored bacterial toxicity of treated waste. The amount of sulfate concentration in the treated sample is much higher than the sum of the measured inorganic sulfate and the organic sulfur associated with the dinitrotoluene sulfonates initially present in the raw red water. This indicates the presence of other unidentified S-containing organic compounds in red water. The nitrogen analyses indicate a significant NH4+ concentration (32 mg N/l) in treated waste and a high N2 concentration (14.6%; net increase of 4.6%) in the off-gas. The toxicity results indicate that the WO-treated red water exerts toxic effects on Acinetobacter and Nitrosomonas growth, but has less impact on activated sludge. Furthermore, treated samples at 340°C appear to exhibit a more inhibitory effect on both Acinetobacter and Nitrosomonas than those treated at 260°C.

Determination of total particulate sulfur at Whiteface mountain, New York, by pyrolysis microcoulometry

Total paniculate sulfur (TPS) in air samples can be determined by a technique based on thermal volatilization at 1000°C, followed by controlled oxidation of sulfur compounds to SO 2 and coulometric titration of SO 2 with iodine. Calibration curves are linear within 5% from 0.1 to 10 μgS, the detection limit is 0.10μg S (equivalent to 20ng Sm −3 when ~ 1800m 3 of air are filtered), and the relative standard deviations ( n = 10) are 48 and 5.1% at the 0.10 and 4.0 μgS levels. Recoveries for 20 organic and inorganic compounds, including refractory sulfates, elemental sulfur, sulfides, sulfites, sulfonates and sulfones, vary from 79 to 88%. No interferences are observed for a number of non-sulfur-containing compounds, including nitrates, benzene, acetone, glucose, cellulose, silicates and carbonates. The technique was also used to determine the presence of non-sulfates and of non-water-soluble sulfates. Both TPS, using this technique, and water-soluble sulfate (WSS), using the methyl thymol blue method, were determined in daily air particulate samples collected at Whiteface Mountain, NY during both winter and summer. Comparision of TPS and WSS values showed that WSS could usually account for all of the sulfur present in the samples. The TPS concentrations ranged from 0.1 to 9.7μg Sm −3 and the contribution from acid-soluble sulfites and sulfides, elemental sulfur and volatile, S-containing organic compounds was negligible ( < 0.05 μgS m −3).

Improved Technique for Gas Chromatographic Analysis of S-Containing Organic Compounds Using the Flame Photometric Detector

Improved Technique for Gas Chromatographic Analysis of S-Containing Organic Compounds Using the Flame Photometric Detector