Distribution and partitioning of polycyclic aromatic hydrocarbons (PAHs) in different size fractions in sediments from Boston Harbor, United States.

The concentrations of 16 US EPA priority pollutant polycyclic aromatic hydrocarbons (PAHs) were analyzed in four size fractions (< 62, 62-125, 125-250, and > 250 microm) in three contaminated Boston Harbor sediments. Total PAH concentrations ranged from 7.3 to 358 microg/g dry wt. and varied largely among the different size fractions in these sediments. For all three sites, the highest PAH concentrations were associated with the large size (> 250 microm) fractions while the fine silt and clay fractions (< 62 microm) contained relatively low PAHs. Despite the great concentration differences, the composition of PAHs in the four size fractions of these sediments showed similar patterns dominated by PAHs with three or more rings. By examining the distribution patterns of selected alkyl homologs to parent compounds, the results indicate that the major PAHs contributing to the high contamination in the inner harbor sediments were from pyrogenic sources. A positive correlation between PAHs and sedimentary organic carbon exists for all size fractions in the sediments. Calculated organic carbon normalized partition coefficients (log K(oc)) for selected major PAHs indicate near-equilibrium partitioning of PAHs among the different size fractions despite their large concentration variations. Sedimentary organic matter associated with different size fractions was the controlling factor for the observed distribution differences of PAHs among the size fractions. Our results also suggest that sedimentary organic matter with different origins and maturities may have somewhat different PAH sorption characteristics. Particulate organic matter of charcoal, plant detritus and Capitella fecal pellets in the sediments appear to sorb PAHs more strongly than organic matter associated with clay minerals. The strong association of PAHs with these organic particles in sediments will have a great influence not only on their distribution but also on long-term environmental impact.     

Depth-related influences on biodegradation rates of phenanthrene in polluted marine sediments of Puget Sound, WA

A whole-core injection method was used to determine depth-related rates of microbial mineralization of (14)C-phenanthrene added to both contaminated and clean marine sediments of Puget Sound, WA. For 26-day incubations under micro-aerobic conditions, conversions of (14)C-phenanthrene to (14)CO(2) in heavily PAH-contaminated sediments from two sites in Eagle Harbor were much higher (up to 30%) than those in clean sediments from nearby Blakely Harbor (<3%). The averaged (14)C-phenanthrene degradation rates in the surface sediment horizons (0-3 cm) were more rapid (2-3 times) than in the deeper sediment horizons examined (>6 cm), especially in the most PAH polluted EH9 site. Differences in mineralization were associated with properties of the sediments as a function of sediment depth, including grain-size distribution, PAH concentration, total organic matter and total bacterial abundance. When strictly anaerobic incubations (in N(2)/H(2)/CO(2) atmosphere) were used, the phenanthrene biodegradation rates at all sediment depths were two times slower than under micro-aerobic conditions, with methanogenesis observed after 24 days. The main rate-limiting factor for phenanthrene degradation under anaerobic conditions appeared to be the availability of suitable electron acceptors. Addition of calcium sulfate enhanced the first order rate coefficient (k(1) increased from 0.003 to 0.006 day(-1)), whereas addition of soluble nitrate, even at very low concentration (<0.5 mM), inhibited mineralization. Long-term storage of heavily polluted Eagle Harbor sediment as intact cores under micro-aerobic conditions also appeared to enhance anaerobic biodegradation rates (k(1) up to 0.11 day(-1)).     

Vertical distribution of organic compounds in the bottom sediments of two steppe lakes in Southern Siberia

New data on the distribution of organic compounds at different horizons (0–10, 30–40, and 70–80 cm) of bottom sediments of the fresh Fyrkal Lake (Republic of Khakaßsia) and the salt Lake Mormyshanskoe (Altai Territory) have been collected. The compositions of organic compounds in the sediments in the examined lakes has been found to differ considerably, though some parameters in their composition show changes in the same direction. The concentrations of triterpenoids of the groups of lupane, oleanane, and hopane in the sediments decrease with depth. An increase in the share of saturated compounds in the composition of steroids is accompanied by a decrease in the ratio of their isomers (5β/5α). Terrestrial vegetation dominates among organic matter sources, while, in Lake Fyrkal, the contributions of terrestrial plants and macrophytes are similar. The presence of thermally transformed steroids and triterpenoids throughout the vertical profile of sediments in Lake Mormyshanskoe may be an indication to a slight oil pollution of the water body.     

A novel ATR‐FTIR technique for identifying colloid composition in natural waters

Although understanding colloid composition has been frequently cited as essential to predicting contaminant transport in natural waters, most current methods to collect and identify colloid composition chemically alter the colloids prior to analysis and fail to identify colloid mineralogy and organic components. This paper presents a new, low‐cost method employing attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR) to identify colloids including organic material in concentrated suspensions. The concentration method employing tangential ultrafiltration at a steady temperature prevents redistribution of dissolved phase and suspended sediments into the colloidal fraction through post‐sampling reactions. ATR‐FTIR allows for direct analysis of concentrated suspensions rather than requiring drying that may alter composition in the colloidal phase, for example, by precipitating carbonates in samples from karst waters. The ability of this technique to monitor variation in colloidal composition is demonstrated through the examination of colloids under two different flow conditions in a karst aquifer and the West Branch of the Susquehanna River in Central Pennsylvania. Copyright © 2014 John Wiley & Sons, Ltd.     

Contamination of polychlorinated biphenyls (PCBs) in sediments from Kyeonggi Bay and nearby areas, Korea

To elucidate the characteristic distribution and contamination of polychlorinated biphenyls (PCBs) in sediments, 63 sediments and five benthic organisms from Kyeonggi Bay, Namyang Bay and Lake Shihwa, West coast of Korea, were analysed. Characterization of PCBs distribution in sediments was conducted by correlation between PCBs concentrations and environmental parameters, comparison of contamination level and composition of PCBs homologs between Kanechlor mixture (KC-mix) and sediments. The residues of PCBs in sediments were correlated with total organic carbon (TOC) and particulate organic carbon (POC) contents, not with mud contents and grain size distributions. Elevated concentrations of T-PCBs were found in sediments from Incheon North Harbor (INH) in Kyeonggi Bay. T-PCBs concentrations were decreased with distance increase from inner site of INH. The residues of T-PCBs in sediments from Namyang Bay were either non-detectable or near to detection limit. The contamination by PCBs in sediments from Lake Shihwa was also low. The PCBs congener profiles in INH were similar to those of KC-mix, while those in less contaminated sites showed relatively high percentage of lower chlorinated biphenyls. Sites K18 (580 ng/g or 48 ug/g-OC dry wt) and K19 (330 ng/g or 38 ug/g-OC dry wt) within INH exceeded the sediment quality criteria (SQC) (16 micrograms/g-OC as a KC-mix) derived from equilibrium partitioning (EqP) approach.     

Water quality of a port in NW Mexico and its rehabilitation with swell energy

Ensenada Harbor is one of the most important ports of Mexico. Anthropogenic activities have affected the area over several decades, leading to the accumulation of contaminants in its sediments, which eventually are re-suspended into the water column. In spite of water treatment of the tributaries that discharge into the Ensenada Harbor, the water circulation patterns of the harbor, which consist of closed eddies in the northern and southeastern sector, favor the accumulation of those contaminants and hinder exchange with adjacent seawater. Samples collected in October of 2005 registered 63 μM total inorganic nitrogen and 280 mg/L of COD, confirming that this is a highly contaminated environment when compared with other water bodies of North America. Such concentrations can be lowered up to 80% by using a wave energy pumping system that demonstrates the possibility to gradually dilute these contaminants and rehabilitate the Ensenada Harbor.     

Levels of estrogenic compounds in Xiamen Bay sediment, China

Concentrations of seven estrogenic compounds, i.e., estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol(EE2), diethylstilbestrol (DES), nonylphenol (NP), octylphenol (OP) and bisphenol A (BPA), were determined in sediments and pore water from Xiamen Bay in China, and their distributions and potential risks in the Bay were assessed. Total estrogenic compounds concentrations varied from 49.20 to 1230.69 ng/g dw in sediments and from 102.33 to 4376.60 ng/L in pore water. The highest levels of these compounds were found at Yundang Lagoon. The results showed that estrogenic compounds in Xiamen Bay originated mainly from municipal wastewaters. Compared with other areas, Xiamen Bay was contaminated with high levels of estrogen hormones. This contamination poses a potential threat to benthic organisms. Although a good relationship (r = 0.94) was observed between the estrogenic compounds concentrations and total organic carbon (TOC) contents in sediments, which did not indicate that the sediment organic matter favors the accumulation of the detected estrogenic compounds.     

Potentially Bioavailable Natural Organic Carbon and Hydrolyzable Amino Acids in Aquifer Sediments

This study evaluated the relationship between concentrations of operationally defined potentially bioavailable organic ‐carbon (PBOC) and hydrolyzable amino acids (HAAs) in sediments collected from a diverse range of chloroethene‐‐contaminated sites. Concentrations of PBOC and HAA were measured using aquifer sediment samples collected at six selected study sites. Average concentrations of total HAA and PBOC ranged from 1.96 ± 1.53 to 20.1 ± 25.6 mg/kg and 4.72 ± 0.72 to 443 ± 65.4 mg/kg, respectively. Results demonstrated a statistically significant positive relationship between concentrations of PBOC and total HAA present in the aquifer sediment (p < 0.05). Higher levels of HAA were consistently observed at sites with greater levels of PBOC and first‐order decay rates. Because amino acids are known to be readily biodegradable carbon compounds, this relationship suggests that the sequential chemical extraction procedure used to measure PBOC is a useful indicator of bioavailable carbon in aquifer sediments. This, in turn, is consistent with the interpretation that PBOC measurements can be used for estimating the amount of natural organic carbon available for driving the reductive dechlorination of chloroethenes in groundwater systems.     

Remediation of the Wells G & H Superfund Site,Woburn, Massachusetts

Remediation of ground water and soil contamination at the Wells G & H Superfund Site, Woburn, Massachusetts, uses technologies that reflect differences in hydrogeologic settings, concentrations of volatile organic compounds (VOCs), and costs of treatment. The poorly permeable glacial materials that overlie fractured bedrock at the W.R. Grace property necessitate use of closely spaced recovery wells. Contaminated ground water is treated with hydrogen peroxide and ultraviolet (UV) oxidation. At UniFirst, a deep well completed in fractured bedrock removes contaminated ground water, which is treated by hydrogen peroxide, UV oxidation, and granular activated carbon (GAC). The remediation system at Wildwood integrates air sparging, soil-vapor extraction, and ground water pumping. Air stripping and GAC are used to treat contaminated water; GAC is used to treat contaminated air. New England Plastics (NEP) uses air sparging and soil-vapor extraction to remove VOCs from the unsaturated zone and shallow ground water. Contaminated air and water are treated using separate GAC systems. After nine years of operation at W.R. Grace and UniFirst, 30 and 786 kg, respectively, of VOCs have been removed. In three years of operation, 866 kg of VOCs have been removed at Wildwood. In 15 months of operation, 36 kg of VOCs were removed at NEP. Characterization work continues at the Olympia Nominee Trust, Whitney Barrel, Murphy Waste Oil, and Aberjona Auto Parts properties. Risk assessments are being finalized that address heavy metals in the floodplain sediments along the Aberjona River that are mobilized from the Industri-Plex Superfund Site located a few miles upstream.     

沉水植物苦草(Vallisneria natans)对多环芳烃污染沉积物的修复作用

沉水植物是浅水湖泊生态系统的关键种群,对水环境质量及水生生态系统结构有重要影响.以东太湖大水港和湖湾区2个典型的具有不同污染程度的沉水植物苦草(Vallisneria natans)生长区域为研究对象,考察苦草对多环芳烃(PAHs)的修复效果.结果表明,经过34 d植物修复试验,重度污染的东太湖大水港沉积物中PAHs的去除率为62%,沉积物中PAHs降解速率为0.024 d-1;而中度污染的东太湖湖湾区沉积物的PAHs去除率为42%,其降解速率为0.015 d~(-1).种植苦草的沉积物中PAHs的降解速率是未种植苦草的降解速率的2~3倍.苦草对沉积物中高分子量PAHs的修复效果尤为显著.因此,苦草可以有效地用于PAHs污染沉积物的修复,尤其是在重污染和高分子量PAHs污染沉积物中,苦草的修复作用更加明显.     

Effect of phosphatation and calcination on the environmental behaviour of sediments

Dredging operations produce considerable quantities of materials, to be managed and this opens an opportunity for valorization in civil engineering. However, the contamination of the dredged sediments has become a major problem to solve. The major contaminants are heavy metals and organic compounds. This study focuses on the use of phosphoric acid (H3PO4) to stabilize heavy metals from sediments and destroy organic matter by calcination at 650 °C with a goal of using sediments in roadworks. Several studies have been conducted in this eld. The stabilized materials obtained have been used in civil engineering. The main purpose of this work is to discuss the environmental behavior of marine sediment treated by phosphatation and calcination. Two types of phosphoric acids were used. The pH dependence leaching test has been used as the basic characterization to evaluate the effect of the type of phosphoric acid on the metals behavior in a valorization scenario. The standard leaching test and the Toxicity Characteristic Leaching Procedure (TCLP) were conducted as compliance tests. In regards of the obtained results, the environmental assessment has also shown a reduction in the availability of targeted heavy metals in alkaline environment whatever the type of acid used for treatment. This opens opportunities for co-valorization.     

Petrowatch: Petroleum hydrocarbons,synthetic organic compounds,and heavy metals in mussels from the Monterey Bay area of central California

Mussel Watch techniques were used to measure the concentrations of petroleum hydrocarbons, synthetic organic hydrocarbons, and trace metals in a preliminary study of the Monterey Bay area in central California. Resident mussels were found to have higher-than-expected petroleum hydrocarbon body burdens in Carmel Bay, an area thought to be relatively contaminant free. A ‘hot spot’ of PCB 1254 and pp′DDE was measured at Año Nueuvo Island, a site previously recognized because of elevated levels of mercury in mussels. PCB 1254 concentrations at Año Nuevo Island were high in relation to the remainder of coastal United States and Baja California, reflecting entrainment of this compound at a biologically active area. The Monterey Harbor Jetty location showed the highest contamination levels for zinc and lead. In fact, this location has the second highest lead concentrations in mussels for the California coast. Biological cycling of certain compounds (PCB, DDT and mercury) in remote locations such as Año Nuevo Island, is hypothesized as a mechanism for these elevated concentrations in mussels. Levels of other synthetic organic hydrocarbons were generally low, with chlordanes showing higher concentrations in the more urbanized locations of the study area, i.e. the Monterey Harbor Jetty.     

Sedimentary processes in the inner New York Bight: Evidence from excess210Pb and239,240Pu

Particle-reactive radionuclides were determined in sediments from the inner New York Bight to trace transport and storage of fine-grained sediments and associated reactive materials. Seven sediment ? cores 20–50 cm in length were analyzed for water content, loss on ignition (LOI) and excess²¹⁰Pb; three of these were also analyzed for^239,240Pu. Excepting some depth horizons in a core from a dredge-spoil dumpsite, every sample analyzed contained excess²¹⁰Pb. Variations in the concentration of excess²¹⁰Pb with depth in the sediment at all stations correlated strongly with LOI, which apparently traces that fraction of the sediment which is active in removing reactive elements from the water column. In the cores analyzed for^239,240Pu, every sample contained finite Pu, and Pu concentrations correlated strongly with excess²¹⁰Pb.The radionuclide distributions may be simply viewed as products of steady-state sediment accumulation or of mixing. Geochemically reasonable accumulation rates are very high (0.5–2.6 g/cm² y) and could probably only be sustained by offshore transport of dumped materials. At the other extreme the relationships between excess²¹⁰Pb and LOI are compatible with rapid mixing of a²¹⁰Pb carrier phase (traced by LOI) into the pre-existing substrate with little or no actual accumulation. Other non-steady-state processes, such as sediment gravity flow, could also explain the observed distributions.Measured sediment inventories (dpm/cm²) of excess²¹⁰Pb and Pu at these stations are greatly in excess of those supportable by direct atmospheric deposition: lateral supply is required. Incorporation of sedimentary fines into the sand substrate could make the inner New York Bight an important repository of reactive materials.     

Correlation assessment and monitoring of the potential pollutants in the surface sediments of Pyeongchang River, Korea

The study provides a baseline for the assessment of the organic and inorganic pollution specially, heavy metal contamination in the surface sediments of Pyeongchang River,South Korea.The assessment of the study areas was done with respect to metal pollution load,ecological risk and geoaccumulated risk.Based upon the used indices,a priority index(P_index) was used to rank the utmost contaminated sites.Though the concentrations of mercury in all sediments were below the guideline, the significant enriched contamination was observed by all applied indices.As expected,the values of pollution load index（PLI）,ecological risk index（RI） and geoaccumulation risk index(I_geo) demonstrated lower heavy metal contamination in upstream areas compared to the downstream. Admittedly,sediments were unpolluted to slightly-polluted according to PLI while high to extremely high ecological risks were observed in several sediment samples.Furthermore,all the samples were uncontaminated as per I_geo.After simplification of I_geo,the P_index,showed the utmost contaminated sediments with a value of 2.537.Notably,protective measures should be taken to the highly contaminated areas which are prioritized by P_index Admittedly,the maximum concentrations of total organic carbon,total nitrogen,inorganic nitrogen,total phosphorous,inorganic phosphorous,calcium, magnesium,sodium and potassium were significantly observed as 7.8×10⁴,3,185,36,1,032,3.7, 1,5163,2,881,669 and 4,076mg/kg accordingly.     

Polybrominated diphenyl ether congeners in the young-of-the-year bluefish,Pomatomus saltatrix,from several nursery habitats along the US Atlantic coastline

Spatial trends of polybrominated diphenyl ether (PBDE) congeners were examined by using high resolution gas chromatography – low resolution electron impact mass spectrometry (GC-EIMS) in 414 samples of young-of-the-year (YOY) bluefish (Pomatomus saltatrix) collected from a total of 29 nursery habitats along the US Atlantic coastline from Massachusetts to Florida. Of the 26 target PBDE congeners, BDE-47 (4 Br), BDE-100 (5 Br), BDE-49 (4 Br), BDE-99 (5 Br), and BDE-154 (6 Br) were the five most frequently detected congeners in the order of decreasing importance. The sum of the concentrations of five major PBDE congeners, referred to as ΣPBDEs, varied between estuaries and also among samples from a given estuary. ΣPBDEs were lowest in YOY bluefish from Vineyard Sound, Nantucket Sound, Great Bay, Delaware Bay, Lynnhaven Bay, Cape Lookout, and Crescent Beach, with maximum ΣPBDE concentrations below 10 ng/g wet weight. ΣPBDEs in three bluefish samples from Stamford Harbor were detected at relatively high to unusually high concentrations of 69.1, 205, and 561 ng/g wet weight. ΣPBDE values for other Stamford Harbor bluefish were generally low. Highest PBDE concentrations were detected in the vicinity of industrial and urban locations within the New York – New Jersey metropolitan complex. Among them, bluefish from Newark Bay were generally the most contaminated with an average ΣPBDE value of 56.6 ± 30.8 ng/g wet weight. ΣPBDEs in bluefish from Newark Bay were numerically greater than ΣPBDEs in bluefish from all locations, however these differences were not statistically significant. Modest to good correlations between ΣPBDEs and lipids were observed for YOY bluefish from Buzzards Bay, Upper New Bedford Harbor, Lower New Bedford Harbor, Outer New Bedford Harbor, Providence Harbor, Housatonic River, Norwalk Harbor, Little Neck Bay, Newark Bay, Sandy Hook Bay, Great Bay, Delaware Bay, Patuxent River and Crescent Beach. Poor correlations between ΣPBDE and lipids were observed for bluefish from other estuaries. ΣPBDEs were not always correlated with fish length or weight. ΣPBDEs in YOY bluefish along the US Atlantic coastline modestly paralleled ΣPBDEs in mussels and oysters, from not exact but geographically loosely similar locations, reported in the NOAA Mussel Watch Program. A number of researchers who used the high resolution mass spectrometry reported additional PBDE congeners. Although PBDE congeners we report do appear to be the prominent congeners in these studies, it is likely that the comparisons will be skewed in certain instances.     

Vertical changes of POC flux and indicators of early degradation of organic matter in the South China Sea

Tie-series sediment trap materials at different water depths and surface sediments in northern and central South China Sea (SCS) were analyzed for organic carbon, amino acids, amino sugars and carbohydrates. Results show that particulate organic carbon (POC) is mainly derived from marine plankton, only 1.4%–1.6% of primary production sinks into deep SCS water column and less than 0.22 % of primary production ultimately reaches the sediments. The ranineralization and dissolution of organic matter as well as the compositional alterations of organic matter mixtures may mainly take place in the upper few hundred meters of water column, deep carbonate (opal) lysocline zones, and interface layers between sediments and water column, rather than in mid-waters. The organic geochemical parameters such as (T ^aa +T ^sug )OC%, AA/AS, Gluam/Galam, Arom. AA/non-prot. AA, ASP/b-ALA, Glu/g-ABA decrease from living marine plankton (or planktonic shells), to settling particulate matter and to sediments suggesting that they appear to be gad early degraded indicators of organic matter. Project supported by the National Natural Science Foundation of China (Grant No. 49776297). Cruises financially supported by State Oceanic Administration and German Federal Ministry of Research and Technology.     

湖泊沉积有机碳同位素与环境变化的研究进展

湖泊沉积有机质稳定碳同位素（δ^13Corg)在区域气候与环境变化方面的应用近年来发展迅速,成果令人瞩目,保存在各类湖泊岩芯中的δ^13Corg记录揭示了晚更新世以来大气CO2浓度的变化、湖泊水位波动、湖区生态与植被的变迁以及气温变化等重要环境信息,由于造成δ^13Corg值变化的影响因素较多,确定个湖与环境变化有关的主导因素时常有赖于其它证据的帮助,诸如地球化学、古湖沼学、孢粉学、分子同位素地层学等等,前人通过研究来自不同类型湖泊、具不同曲线形态特征的δ^13Corg记录,提出了多种环境解释模型,本文对此作了归纳和评述。鉴别和澄清湖泊沉积有机质的源物质以及有机物源随环境变化而发生过的变化,是研究δ^13Corg记录环境意义至关重要的基础性工作,由于有机质含量、碳氮比值、氢指数、生物残留物鉴别等常能提供有关有关湖泊有机质来源、产率、成岩作用等方面的有用信息,这方面的研究结果应该尽可能一并提供,以利于恰当地应用现有的环境解释模型,或者建立个湖新模型,单体生物标志化合物鉴别通常也能为区分湖积有机质中陆生、水生、细菌生等不同碳的来源提供有用信息,特定化合物同位素分析技术近年来成功地应用于建立单体生物标志化合物碳同位素地层学,为湖积有机碳同位素在生态环境演变研究方面的应用提供了思路,我国许多湖泊的湖底沉积岩芯尚未钻取,那些对过去全球变化研究有价值的δ^13Corg记录有待我们去获取和研究。     

Molecular evidence for life in the 3.5 billion year old Warrawoona chert

The biological origin of organic matter in the oldest siliceous sediments (cherts) is still debated. To address this issue, the insoluble organic matter (kerogen) was isolated from a chert of the Warrawoona group. The chemical structure of the kerogen was investigated through a combination of analytical techniques including solid-state ¹³C nuclear magnetic resonance and pyrolysis. Although dominated by aromatic hydrocarbons, the pyrolysate comprises a homologous series of long chain aliphatic hydrocarbons characterized by odd-over-even carbon number predominance. This distribution is only consistent with a biological origin. As kerogen must be contemporaneous of the solidification of the chert, this observation should be regarded as an evidence for the presence of life on Earth, 3.5 By ago.     

Fourier transform infrared microspectroscopic characterization of Neoproterozoic organic microfossils from the Fifteenmile Group in Yukon,Canada

Conventional and synchrotron radiation‐based (SR) Fourier transform infrared microspectroscopies (micro‐FTIR) were applied to four types of ~ 810 Ma organic‐walled microfossils together with diffuse organic matter (OM) and one irregularly shaped structure from the Fifteenmile Group, in Yukon, Canada, for their chemical characterization. The microfossils comprised one filamentous type and three coccoidal types. Micro‐FTIR mapping analysis revealed the micrometer‐scale, spatial distribution of organic components (aliphatic C‐H bonds) and carbonate in the microfossils. Based on comparisons of CH₃/CH₂ peak height ratios (R_3/2) and morphologies of the microfossils (without the diffuse OM) to those of previously described Proterozoic microfossils, possible affinities of the microfossils are suggested, as follows. Palaeolyngbya? and Glenobotrydion belong to bacteria. Myxococcoides is not clearly characterized due to the significant mixing with diffuse OM containing abundant aliphatic C‐H groups. The irregularly shaped structure may represent a eukaryote. The diffuse OM may represent a mixture of decomposed microbial cells and extracellular polymeric substances (EPS). SR micro‐FTIR measurements of two coccoid types (Glenobotrydion and Unnamed Coccoid Form D) revealed that the R_3/2 values of the internal spots with wall structures are similar to those without wall structures in Glenobotrydion: those values from Unnamed Coccoid Form D were different. The results suggest that these two coccoids are different chemically as well as morphologically. Micro‐FTIR characterization of the organic‐walled microfossils together with morphological analysis provides new insight into their biological affinities.     

Study of the Interaction Mechanism in the Biosorption of Copper(II) Ions onto Posidonia oceanica and Peat

A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption–desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4–6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q_max) at pH 6 of 85.78 and 49.69 mg g^?1, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO₃)₂, and EDTA was applied to copper‐saturated biosorbents. Around 65–70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH₂, and CH₃ in aliphatic structures, COO^? and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si? O groups on the surface of peat. The results of SEM‐EDX and FTIR analysis of copper‐saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption–desorption processes affected the thermal stability of the biosorbents.