Major Organic Constituents Research Articles

Chrysophyllum Albidum extract as a new and green protective agent for metal

ABSTRACT Gravimetric measurements and potentiodynamic polarization techniques were employed to investigate the protective performance of the metal in 1 M HCl and 0.5 M H2SO4 solutions by the C. albidum leaf extract at different concentrations (400-1600 mg/L) and time periods (1-4 days). The results showed the highest protection ability of over 96-97%, with inhibition increasing with higher extract concentrations. Polarization studies indicated a mixed inhibition mechanism, reducing both anodic dissolution and cathodic hydrogen evolution rates. Gas chromatography–mass spectrometry (GC–MS) analysis identified major organic constituents in the extract. Thermodynamic data fit the Langmuir isotherm model, suggesting chemisorptive adsorption of inhibitor molecules on the mild steel surface. Computational methods, including density functional theory (DFT), molecular dynamics simulations, and quantum chemical calculations, provided insight into inhibitor-metal interactions and adsorption behaviour at the molecular level. Overall, the study establishes C. albidum leaf extract as an effective, sustainable alternative to commonly used toxic chromate and phosphate inhibitors. It performs competitively even at low concentrations and in environments. The promising green inhibition properties, combined with the extract's nontoxicity and abundance from a natural source, suggest its potential as a cost-effective corrosion protection solution, especially for applications in developing economies.

Optimization of bio-crude yield and its calorific value from hydrothermal liquefaction of bagasse using methanol as co-solvent

Hydrothermal liquefaction is a promising resource recovery technique to valorize wet lignocellulosic agro residues. In this study, hydrothermal liquefaction of bagasse was performed at different temperatures (280, 300, 320 °C), reaction times (15, 30, 45 min), and amount of KOH catalyst (5, 7.5, 10 wt%) in the presence of methanol as a co-solvent. The process conditions were optimized using response surface methodology to maximize the yield of bio-crude and its higher heating value (HHV). Maximum bio-crude yield of 36.3 wt% was obtained at 320 °C, 15 min and 10 wt% KOH. The bio-crude yield was found to depend on temperature, amount of KOH, and the interaction of reaction time and amount of KOH. Maximum HHV of bio-crude (34.6 MJ kg−1) was recorded at 320 °C, 45 min and 10 wt% KOH, and this condition corresponded to highest deoxygenation achieved in the bio-crude. The major organic constituents in the bio-crude were cyclo-oxygenates, phenolics, and esters, and their combined selectivity was 78–83%. Maximum energy recovery of 56% was obtained. The energy content of the solid residue was high (∼23 MJ kg−1) at the center point corresponding to 300 °C, 30 min and 7.5 wt% KOH. The process exhibited positive energy gain with favorable sustainability metrics.

Antifungal activity and volatile organic compounds analysis of essential oils from Cymbopogon species using solid-phase microextraction-gas chromatography-mass spectrometry

Abstract The essential oils extracted from Cymbopogon flexuosus, Cymbopogon winterianus, Cymbopogon martini were analyzed by trapping the volatile organic compounds using solid-phase microextraction-gas chromatography-mass spectrometry and evaluated their antifungal activity against plant fungal pathogens like Fusarium oxysporum f. sp. cepa (Hypocreales: Nectriaceae) and Sclerotium oryzae Cattan (Magnaporthales: Magnaporthaceae). The major volatile organic constituents of C. flexuosus-citral (22.94%), neral (19.88%), camphene (8.37%), cyclohexene, 1-methyl-5-(1-methylethenyl-(R) (5.75%); C. winterianus-citronellal (42.47%), D-limonene (10.86%), geraniol (9.44%), citronellol (6.25%); C. martini-geraniol (43.80%), a-ocimene (10.75%), geranyl acetate (6.35%), 2,6-octadienal, 3,7-dimethyl-(E) (5.83%), were found in concentrations higher than 5.0% (calculated as % peak area of GC-MS analysis using a nonpolar column). In addition, the antifungal tests were also demonstrated that the essential oil of C. flexuosus C. winterianus and C. martini have excellent inhibitory effect against S. oryzae and F. oxysporum. The IC50 values of essential oils from C. flexuosus, C. winterianus and C. martini against at S. oryzae and F. oxysporum were 0.42, 0.41, 1.99 and 0.73, 2.02, 2.01 μL/plate respectively. The significant aroma may be the results of combined 30 volatile organic compounds from essential oils of Cymbopogon species which could be used as safe biocontrol agents to prevent stored product commodities from fungal pathogens.

Distribution of protein fractions in tofu whey wastewater and its potential influence on anaerobic digestion

Wastewater from tofu (soybean curd) production contains a high organic concentration that might pollute the environment if it is not treated properly. Among the major organic constituents of tofu wastewater are proteins. Degradation of proteins generates ammonia and H2S gases, and if this occurs in an anaerobic digester might hamper the digester’s performance. On the other hand, proteins can potentially be recovered as value-added products. This research aimed to identify protein amounts in different fractions of tofu wastewater, as a basis of designing a process to recover the proteins. Furthermore, the influence of a lower protein concentration to anaerobic digestion of tofu wastewater was calculated. Tofu wastewater was fractionated by gravity settlement and filtration into settleable, suspended, and dissolved fractions. Subsequently, total solids, protein, and COD concentrations of each fraction were analysed. Our results show that tofu wastewater contained 2.9 g-protein/L, equivalent to 4 g-COD/L. While most of the proteins were dissolved, 9% of the proteins were settleable. This might be recovered via a settling chamber. Using the protein-separated wastewater in anaerobic digestion might reduce NH3 and H2S by 10% while only reduce biogas production by 2%.

Effects of fuel content and density on the smoldering characteristics of cellulose and hemicellulose

Smoldering combustion in wildland fires poses hazards for both ecosystems and humans by destroying biomass, transitioning to flaming combustion, and releasing significant quantities of pollution. Understanding the parameters that control smoldering is necessary to help predict and potentially mitigate these hazards. A challenge in identifying these parameters is the wide variety of biomasses which occur in nature. The objective of this study is to identify the effects of density and fuel concentration on the smoldering characteristics of cellulose and hemicellulose mixtures. These fuels were considered because they are some of the major organic constituents within biomass. To this end, downward smoldering propagation velocities were measured for 50%, 75%, and 100% cellulose content at densities varying from 170 to 400 kg/m3. The horizontal smoldering propagation velocities and temperature distributions were also determined for loosely packed samples ranging from 100% to 0% cellulose (with residual hemicellulose). Additionally, horizontal smoldering propagation velocities were determined for systematically varied ratios of cellulose (50–100%) and densities (200–400 kg/m3). The fuel was burned in an insulated reactor box. An infrared camera measured the horizontal propagation velocity, and thermocouples measured the downward propagation. A one-dimensional reactive porous media model with reduced chemistry was used to identify key processes causing the observed sensitivities. At constant packing density, the propagation velocity increased as cellulose content decreased because of decreased heat release with increased cellulose content and the earlier onset of hemicellulose pyrolysis. The propagation velocity decreased with respect to packing density when the fuel content was constant because of reduced oxygen diffusion. The propagation velocity increased with cellulose content when the fuel was loosely packed because of the decreasing density.

Non-Collagen Protein in the Dentin Tissue – The Role in the Process of Dentinogenesis

Collagen forms the major organic constituent of human tooth dentin with non-collagen proteins and proteoglycans contributing for minor fragment. Studies involving the nature of non–collagen proteins are comparatively rarer than the other dentinal components. With this background the authors conducted the present study. To identify the specific and unspecific non-collagen proteins in the dentin. Samples of teeth tissue prepared using guanine hydrochloride in natrium acetate and then subjected to polyacrylamide gel electrophoresis. The samples were visualized using Coomassie Blue coloring technique. The pattern of electrophoresis of dentin fraction indicated large protein component. The mass spectrometric analysis results of the two gel parts confirmed the presence of dentin sialoprotein and bone sialoprotein in the dentin fraction. Difference in the molecular mass was evident between the two protien fractions. The authors suggest that since dentin sialoprotein is specific to dentin and not identified in any other tissue, it may be a unique constituent and may play a critical role in formation of dentin.

Particulate and gaseous emissions from charcoal combustion in barbecue grills

The use of charcoal for cooking and heating can be a major source of air pollution and lead to a wide range of health outcomes. The aim of this study was to experimentally quantify and characterise the gaseous and particulate matter (PM2.5) emissions from charcoal combustion in a typical brick barbecue grill. The gaseous emission factors were 219 ± 44.8 g kg−1 for carbon monoxide (CO), 3.01 ± 0.698 g kg−1 for nitrogen oxides (NOx expressed as NO2), and 4.33 ± 1.53 gC kg−1 for total organic carbon (TOC). Particle emissions (7.38 ± 0.353 g kg−1 of dry charcoal burned) were of the same order of magnitude as those from traditional residential wood burning appliances. About 50% of the PM2.5 emitted had a carbonaceous nature while water soluble ions accounted, on average, for 17% of the particulate mass. Alkanes (C11–C16 and C23), hopanes, steranes and alkyl-PAHs accounted for small mass fractions of PM2.5. Phenolic compounds and saccharides represented the major particle-bond organic constituents. The high proportion of either resin acids or syringyl and vanillyl compounds is consistent with emissions from charred coniferous wood. The ratios between anhydrosugars for charcoal are much lower than the values reported for lignite combustion, but overlap those from other biomass burning sources.

Mild steel green inhibition by Ficus carica leaves extract under practical field conditions

Various electrochemical techniques were employed to study the effectiveness of aqueous Ficus carica (Fig. tree) leaves extract as green corrosion inhibitor for mild steel under field conditions containing 3.5% sodium chloride solution saturated with carbon dioxide. Optimum inhibition efficiency of 90% was obtained using 50 mg/L of inhibitor in the temperature range of 25–40 °C. The mode of action of Ficus carica leave extract as revealed by Polarization studies was shown to act as a mixed inhibitor. The adsorption isotherm of the adsorption of Ficus carica leaves extract on the steel surface was found to follow Langmuir adsorption isotherm. In order to assess the individual contribution of the different constituents of the extract theoretically, the adsorption of the four major organic constituents of Ficus carica leave extract on mild steel were modelled using density functional theory and quench molecular dynamic simulations. Among the four major Ficus carica leaves extract constituent investigated, Caffeoylmalic acid was found to make the most contribution to the overall inhibition action of Ficus carica leaves extract.

Anode macrostructures influence electricity generation in microbial fuel cells for wastewater treatment

Microbial fuel cells (MFCs) are devices that exploit microbes for generating electricity from organic substrates, including waste biomass and wastewater pollutants. MFCs have the potential to treat wastewater and simultaneously generate electricity. The present study examined how anode macrostructure influences wastewater treatment, electricity generation and microbial communities in MFCs. Cassette-electrode MFCs were equipped with graphite-felt anodes with three different macrostructures, flat-plate (FP), vertical-fin (VF), and horizontal-fin (HF) structures (these were composed of a same amount of graphite felt), and were continuously supplied with artificial wastewater containing starch as the major organic constituent. Polarization analyses revealed that MFCs equipped with VF and HF anodes generated 33% and 21% higher volumetric power densities, respectively, than that of MFCs equipped with FP anodes. Organics were also more efficiently removed from wastewater in MFCs with VF and HF anodes compared to reactors containing FP anodes. In addition, pyrosequencing of PCR-amplified 16S rRNA gene fragments from microbial samples collected from the anodes showed that the presence of fins also affected the bacterial compositions in anode biofilms. Taken together, the findings presented here suggest that the modification of anodes with fins improves organics removal and electricity generation in MFCs. The optimization of anode macrostructure therefore appears to be a promising strategy for improving MFC performance without additional material costs.

MBR处理电镀废水出水中DOM的特征分析

利用XAD-8/XAD-4树脂对膜生物反应器(MBR)处理电镀废水出水中的溶解性有机物(DOM)进行了组分分离，将DOM分为过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)、疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)和亲水性有机物(HPI)五个组分，并对重金属冲击前后各组分的溶解性有机碳(DOC)、紫外–可见光谱和多糖的变化情况进行对比分析.结果表明，HPI、HPO-A和HPO-N是电镀废水中主要的有机成分，共占总DOC的87.5%，MBR的生物降解作用更适合去除疏水性物质含量较高的有机废水.电镀废水中的芳香性有机物主要来自HPO-N，多糖主要分布在HPO-A、HPO-N和TPI-N中。MBR对中性有机物的去除效果较好，重金属冲击前TPI-N和HPO-N中多糖的去除率分别达到73.3%和99.1%。 Using XAD-8/XAD-4 resins, dissolved organic matter (DOM) in the effluent of membrane bioreactor (MBR) used for electroplating wastewater treatment was fractionated into five fractions: transphilic acid (TPI-A), transphilic neutral (TPI-N), hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), and hydrophilic fraction (HPI). Thereafter, the changes of dissolved organic carbon (DOC), ultraviolet visible spectroscopy and polysaccharide of each fraction before and after metal impact were analyzed. HPI, HPO-A and HPO-N are the major organic constituents in electroplating wastewater, accounted for 87.5% of total DOC, biodegradation of MBR is more suitable for the removal of organic wastewater with high content of hydrophobic substances. Aromatic compounds in electroplating wastewater mainly from HPO-N, polysaccharide mainly distributed in HPO-A, HPO-N and TPI-N, TPI-N and HPO-N. The effect of MBR on the removal of neutral compounds is better. Before the impact of heavy metals, the removal rates of TPI-N and HPO-N were 73.3% and 99.1%, respectively.

Confirming anthropogenic influences on the major organic and inorganic constituents of rainwater in an urban area

Abstract. Recently, rainwater composition affected by atmospheric pollutants has been the topic of intense study in East Asia because of its adverse environmental and human health effects. In the present study, the chemical composition and organic compounds of rainwater were investigated from June to December 2012 at Gwangju in Korea. The aim of this study is to determine the seasonal variation of rainwater chemical composition and to identify possible sources of inorganic and organic compounds. The volume-weighted mean of pH ranged from 3.83 to 8.90 with an average of 5.78. Of rainwater samples, 50 % had pH values below 5.6. The volume-weighted mean concentration (VWMC) of major ions followed the order Cl− > SO42− > NH4+ > Na+ > NO3− > Ca2+ > Mg2+ > K+. The VWMC of trace metals decreased in the order Zn > Al > Fe > Mn > Pb > Cu > Ni > Cd > Cr. The VWMCs of major ions and trace metals were higher in winter than in summer. The high enrichment factors indicate that Zn, Pb, Cu, and Cd originated predominantly from anthropogenic sources. Factor analysis (principal component analysis) indicates the influence of anthropogenic pollutants, sea salt, and crustal materials on the chemical compositions of rainwater. Benzoic acids, 1H-isoindole-1,3(2H)-dione, phthalic anhydride, benzene, acetic acids, 1,2-benzenedicarboxylic acids, benzonitrile, acetaldehyde, and acetamide were the most prominent pyrolysis fragments for rainwater organic compounds identified by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The results indicate that anthropogenic sources are the most important factors affecting the organic composition of rainwater in an urban area.

Evaluation of source rock potential, matrix effect and applicability of gas oil ratio potential factor in Paleocene–Eocene bituminous shales of Çamalan Formation, Nallıhan – Turkey

In order to improve the reliability and accuracy of source rock evaluation, a total of 102 shale samples of Çamalan Formation were collected, analyzed and re-characterized with taking matrix retention effect into account. Results from Rock-Eval and visual kerogen analyses indicate: 1. an excellent source rock with an average TOC of 6.39 wt.%. 2. An assemblage of amorphous (i.e., alginite, type I) organic matter as a major organic constituent with an excellent potential for generating oil. 3. Shale samples from Çamalan Formation are in immature/early–intermediate stage of maturity based on Tmax (Avg. ∼440 °C) and spore color index (SCI ∼2.5–4). Also no amount of Çamalan generated oils are migrated out of shale based on S1 vs. TOC plot. (i.e., Transformation ratio (TR ∼0)). Samples of this study show a significant mineral matrix effect. After correction of mineral matrix effect the average hydrogen index (HI) of the Çamalan Formation increased by more than 60 mg HC/g TOC and reached to an average of 811 mg HC/g TOC. Gas oil ratio potential (GORP) factor were used in order to split up the TOC and S2 into oil-prone and gas-prone and also to investigate the level of consistency between the results of GORP factor and those of visual kerogen studies. Based on obtained GORP factor more than 90% of TOC(live) is composed from oil-prone materials which is in acceptable agreement with petrographic assessments.

Chemical characterization of sub-micrometer aerosol particles in the tropical Atlantic Ocean: marine and biomass burning influences

Sub-micron marine aerosol particles (PM1) were collected over the period 22 June–21 July 2011 during the RV MARIA S. MERIAN cruise MSM 18/3, which travelled from the Cape Verdean island of Sao Vicente to Gabon, in the process crossing the tropical Atlantic Ocean with its equatorial upwelling regime. According to air mass origin and the chemical composition of the sampled aerosol particles, three main regimes could be established. Aerosol particles in the first part of the cruise were mainly of marine origin (Region I). In the second part of the cruise, marine influences mixed with increasing influence from biomass burning (Region II). In the final part of the cruise, which approached the African mainland, the biomass burning influence became dominant (Region III). Generally, aerosol particles were dominated by sulfate (caverage = 2.0 μg m−3) and ammonium ions (caverage = 0.7 μg m−3), which were well-correlated and increased slightly over the duration of the cruise. High concentrations of water-insoluble organic carbon (WISOC; caverage = 0.4 μg m−3) were found, most likely as a result of the high oceanic productivity in this region. Water-soluble organic carbon (WSOC) concentrations increased from 0.26 μg m−3 in Region I to 2.3 μg m−3 in Region III, most likely as a result of biomass burning influences. The major organic aerosol constituents were oxalic acid, methanesulfonic acid (MSA), and aliphatic amines. MSA concentrations were quite constant during the cruise (caverage = 42 ng m−3). Aliphatic amines were most abundant in Region I, with concentrations of ~ 20 ng m−3. Oxalic acid showed the opposite trend, with average concentrations of 12 ng m−3 in Region I and 158 ng m−3 in Region III. The α-dicarbonyl compounds glyoxal and methylglyoxal were detected in the aerosol particles in the low ng m−3 range and were closely correlated with oxalic acid. MSA and aliphatic amines arise from biogenic marine sources, whereas oxalic acid and the α-dicarbonyl compounds were attributed to biomass burning. Concentrations of n-alkanes increased from 0.8 to 4.7 ng m−3 over the duration of the cruise. PAHs and hopanes were abundant only in Region III (caverage of PAHs = 0.13 ng m−3; caverage of hopanes = 0.19 ng m−3). Levoglucosan was identified in several samples obtained in Region III, with caverage = 1.9 ng m−3, which points to (aged) biomass burning influences. The organic compounds quantified in this study could explain 8.3 % of WSOC in Regions I, where aliphatic amines and MSA dominated, 3.7 % of WSOC in Region II and 2.5 % of WSOC in Region III, where oxalic acid dominated.

Physiological studies in pteridophytes of Lohgad area, Pune, India

The present study mainly focuses on the physiological importance of pteridophytic floras present in the Lohgad area of Maharashtra state, India. Adiantum, Pteris, Chelanthus farinose, Nephrolepsis cordifolia & Pleopeltis rostrata were commonly found and selected in the present research. Photosynthetic pigments like total chlorophylls, carotenes, Polyphenol, major organic and inorganic constituents like Na, K, Ca, Cu and Mn are reduced in the all pteridophytes studied. Carotenes, Polyphenol content was seen to be maximum in fern, Pleopeltis and Pteris as compared to others. Mg content has maximum in all pteridophytes. In case of Pleopeltis there is maximum concentration of all major inorganic constituents was observed.

Geochemical and petrographic characterization of the Upper Ordovician Utica Shale, southern Quebec, Canada

The Utica Shale is a potential unconventional tight gas reservoir from southern Quebec. The Utica Shale is a calcareous shale with intervals of fine-grained siltstone with total organic content of 1.2wt.% (median, n=408). The major organic matter constituents are migrabitumen and zooclasts (chitinozoan and graptolite) macerals. The primary kerogen is characterized as marine due to the presence of chitinozoan and marine-derived prasinophyte algae such as Tasmanites. A significant portion of the bulk organic matter is dominated by migrabitumen. The present hydrocarbon potential (S2, mgHC/g Rock) of the Utica Shale is largely controlled by distribution of solid migrabitumen throughout the unit. Hydrogen Index (HI) declines with increasing maturity, which is controlled by greater burial from shallow to deep sections. Oxygen Index (OI) remains low in most samples, which is attributed to lack of terrestrial input. However, organic lean intervals show significantly inflated OI due to interference of mineral carbon (possibly siderite).Random reflectance measurements on matrix/solid bitumen and chitinozoans are robust indicators of thermal maturity. The maturity ranges from the late oil window in the shallow Utica to the wet and dry gas windows in the intermediate and deep Utica, respectively.The results suggest that matrix bitumen formed during migration and dissemination of hydrocarbon into the clay fraction of the rock. This is associated with significant bacterial sulfate reduction possibly in the early stages of generation and migration of oil. It appears that the porous siltstone facies in the deeply buried section of the Utica Shale acts as a reservoir for the migrated bitumen from organic-rich strata within the section and/or possibly overlying source rock.

Chemical investigation of the medicinal and ornamental plant Angelonia angustifolia Benth. reveals therapeutic quantities of lupeol

Angelonia angustifolia Benth. is a small herbaceous plant with documented use as an anti-inflammatory remedy by indigenous cultures in Latin America. It has subsequently been developed as an ornamental annual widely available in nurseries in the United States. Chemical investigation led to the discovery that lupeol is the major organic soluble constituent in the roots, and is present in large quantities in the aerial structures of the plant. Lupeol was identified by 1D and 2D NMR spectroscopic techniques and quantified by HPLC-MS. The concentration of lupeol (9.14mg/g in roots) in A. angustifolia is approximately 3 times higher than any previously reported sources. Therefore, the amount of lupeol in the roots of a single individual of A. angustifolia greatly exceeds the previously determined topical threshold for significant reduction of inflammation. The presence of topically therapeutic levels of lupeol in A. angustifolia provides chemical rationale for its indigenous use. In addition, the established cultivation of A. angustifolia could allow this plant to be used as a source of the important bioactive molecule lupeol, or to be developed as a nutraceutical without damaging wild populations.

남극 로스해 퇴적물로부터 분리된 세균의 다양성 및 생리학적 특성

남극 로스해의 퇴적물로부터 배양을 통해 분리한 균주의 분류 및 생리학적 특성 분석을 수행하였다. 분리 세균 63균주의 16S rRNA 유전자 염기서열을 이용한 계통분류학적 분석 결과, 이들은 Actinobacteria, Bacteroidetes, Alphaproteobacteria 및 Gammaproteobacteria 내의 21개의 파일로타입(phylotypes)에 속하였다. 98.65% 염기서열 유사도를 기준으로, 약 49%의 균주가 잠재적으로 신종 또는 신속 후보인 것으로 나타났다. 분리된 균주 중, 각각 46%, 25% 및 32%의 균주가 세포외 단백질분해효소, 지질분해효소 및 외부다당체 생성에 대한 활성을 나타냈다. 43개의 균주는 최소 1개의 세포외 분비 물질을 생산하였고, 이들 중 21개 균주는 최소 2개의 세포외 단백질분해효소, 지질분해효소 또는/및 세포외다당체를 생성하였다. 이러한 결과는 남극 로스해 퇴적물 내의 배양된 세균 군집이 해당 환경에서 탄소와 질소와 관련된 유기물질의 가수분해에 영향을 미치고 있다는 것을 시사한다. The affiliations and physiological characteristics of culturable bacteria isolated from the sediments of Ross Sea, Antarctica were investigated. Sixty-three isolates obtained by cultivation were grouped into 21 phylotypes affiliated with the phyla Actinobacteria and Bacteroidetes and with the classes Alphaproteobacteria and Gammaproteobacteria by phylogenetic analysis of 16S rRNA gene sequences. Based on phylogenetic analysis (<98.65% sequence similarity), approximately 49% of total isolates represented potentially novel species or genus. Among them, extracellular protease, lipase, and exopolysaccharide activities at <TEX>$10^{\circ}C$</TEX> or <TEX>$20^{\circ}C$</TEX> were detected in approximately 46%, 25%, and 32% of the strains, respectively. Forty-three isolates produced at least one type of extracellular material and 21 of them produced at least two extracellular protease, lipase, and/or exopolysaccharides. Our findings indicate that culturable bacterial diversity present within the marine sediments of Ross Sea, Antarctica may contribute to the hydrolysis of the major organic constituents which is closely related with carbon and nitrogen cycling in this environment.

A rapid phenol toxicity test based on photosynthesis and movement of the freshwater flagellate, Euglena agilis Carter

Phenol, a monosubstituted aromatic hydrocarbon with various commercial uses, is a major organic constituent in industrial wastewaters. The ecotoxic action of phenol for aquatic environment is well known. In this study, rapid phenol toxicity tests (1h) were developed based on chlorophyll a (Chl a) fluorescence and the movement parameters of the freshwater flagellate, Euglena agilis Carter. Phenol significantly reduced the maximum quantum yield (Fv/Fm) of photosystem II (PS II) and the maximum photosynthetic electron transport rate (rETRmax) with median effective concentration (EC50) values of 8.94 and 4.67mM, respectively. Phenol reduced the motility and triggered change in the swimming velocity of the test organism. Among the parameters tested, velocity was the most sensitive biomarker with an EC50 of 3.17mM. The EC50 values for Fv/Fm, motility, and velocity appear to overlap the permitted levels of phenol. In conclusion, the photosynthesis and movement of E. agilis can be fast and sensitive risk assessment parameters for the evaluation of phenol toxicity in municipal and industrial effluents.

Classification of clouds sampled at the puy de Dôme (France) based on 10 yr of monitoring of their physicochemical properties

Abstract. Long-term monitoring of the chemical composition of clouds (73 cloud events representing 199 individual samples) sampled at the puy de Dôme (pdD) station (France) was performed between 2001 and 2011. Physicochemical parameters, as well as the concentrations of the major organic and inorganic constituents, were measured and analyzed by multicomponent statistical analysis. Along with the corresponding back-trajectory plots, this allowed for distinguishing four different categories of air masses reaching the summit of the pdD: polluted, continental, marine and highly marine. The statistical analysis led to the determination of criteria (concentrations of inorganic compounds, pH) that differentiate each category of air masses. Highly marine clouds exhibited high concentrations of Na+ and Cl−; the marine category presented lower concentration of ions but more elevated pH. Finally, the two remaining clusters were classified as "continental" and "polluted"; these clusters had the second-highest and highest levels of NH4+, NO3−, and SO24−, respectively. This unique data set of cloud chemical composition is then discussed as a function of this classification. Total organic carbon (TOC) is significantly higher in polluted air masses than in the other categories, which suggests additional anthropogenic sources. Concentrations of carboxylic acids and carbonyls represent around 10% of the organic matter in all categories of air masses and are studied for their relative importance. Iron concentrations are significantly higher for polluted air masses and iron is mainly present in its oxidation state (+II) in all categories of air masses. Finally, H2O2 concentrations are much more varied in marine and highly marine clouds than in polluted clouds, which are characterized by the lowest average concentration of H2O2. This data set provides concentration ranges of main inorganic and organic compounds for modeling purposes on multiphase cloud chemistry.

Foliar Application of Humic Acid on Plant Height in Canola

Humic acid is a principal component of humic substances, which are the major organic constituents of soil. In order to the foliar application of humic acid on plant height in canola spring cultivar (RGS-003 cul.), this experiment was conducted in 2012 at Islamic Azad University Shahr-e-Qods Branch in Tehran by a completely randomized design with four replications. The factors studied included foliar application of humic acid (Control, 0.5, 1, 1.5 and 2%) that sprayed in three stages (stem elongation, flowering stage and silique formation stage). The results showed that foliar application of humic acid significantly affected plant height and highest this parameter was achieved under 2% foliar application of humic acid and the lowest plant height was obtained under control conditions. Also, means comparison showed that plant height under 0.5% foliar application of humic acid and 1% foliar application of humic acid were in a similar statistical group. The results showed that foliar application of humic acid decreased nitrogen application in soil, that can be the most important for the non-pollution of soil by nitrogenous fertilizers.