Monitoring the air quality around an oil refinery through the use of diffusive sampling

Diffusive sampling has been used to study the spatial distribution of SO₂, NO₂, NO_x, NH₃ and BTX (benzene, toluene and xylenes) near an oil refinery located in Falconara, Italy, over the period from March to October 2001. Three different categories of sampling sites (roadside, residential and background) were studied. In total, 56 sites were monitored. The results were evaluated on the basis of the limit values found in the European Directives. The results of the defined study indicate that the measured concentrations were substantially lower than the ambient air quality standard with the maximum concentrations being generally found much closer to emission sources. The monitoring method described here can be used to assess integrated concentration levels over long periods of time and to identify pollution hotspots where concentrations are likely to be consistently high. Identification of these hotspots may help to assess air quality and to implement proper action plans, especially in locations where industrial and urban pollution coexist.     

Monitoring and Evolution of the Pollution by Volatile Organic Compounds (Vocs) in the Groundwaters of The Najerilla River Basin (Spain)

VOCs were detected and identified in the water of several wells in the area of Nájera (La Rioja). The past uncontrolled spills from an important painting and varnishing industry and from other smaller ones devoted to the manufacture of furniture and varnishing activities were the sources of the VOCs plume detected in this aquifer. This article shows the results obtained in the monitoring and assessment of the pollution at 18 sampling points for more than a year. It has allowed us to study the evolution of the different pollutants and the influence of a remediation process applied by the company in the main pollution source. The analytical method is based on headspace-solid-phase microextraction (SPME) using a 75-μm carboxen-polydimethylsiloxane fibre. Quantification was carried out by gas chromatography with flame ionization detection. This method has allowed us to determine the 13 VOCs identified in the polluted underground samples providing good sensitivity (LOD between 0.1 and 6.0 ng/mL) and reproducibility (r.s.d. less than 10%).     

Trace Analysis in Industrial Research

Abstract

Public concern and legislative regulations governing environmental pollution have had a dramatic effect on chemists involved in industrial research. The need to establish both the presence and amounts of trace levels of pollutants in industrial products and wastes has become imperative. Since time and cost become important considerations in such analytical determinations, it is apparent that sensitive, rapid and reliable methods of trace analysis are required. Many experimental techniques have been employed to this end and active research programs exist to develop new techniques to make such analysis more efficient.

Techniques capable of determining many elements in a single examination of a sample are of particular interest. No single 'black box' approach is, or is likely to become, feasible for all species of interest. Nonetheless, certain multielement approaches provide adequate information on some species and also provide important guidelines on the determination of other species by more specialized techniques. Problems encountered and progress achieved by the application of various spectroscopic, chromatographic, electrochemical and chemical methods to the trace analysis of industrial materials will be discussed.     

Monitoring of heavy metals in topsoils, atmospheric particles and plant leaves to identify possible contamination sources

The research reveals results of metal pollution on urban topsoil in relation to the metal content in leaves of two plant species and atmospheric particles. The content of pollutants (Ba, Cd, Cu, Fe, Mn, Ni, Pb, V and Ti) was determined by ICP-OES. Twenty-two samples of soil were collected over a six-month period from two different urban sites and one from a rural zone. Regarding the pollution level, the studied soils were found to be low. Results for enrichment (EF) and concentration (CF) factors showed that soils were enriched in Pb, Ba, Cu and Ni. However, both species of plants showed a common behavior for all elements acting as excluders. ANOVA and different multivariate statistical analyses confirmed that the main pollution source of soil was traffic and fertilizers. Cd, Fe, Mn, Ti and V elements were attributed to natural sources. Also, it was suggested that N. oleander leaf is useful as a bio-monitors of soil pollution by Cu. Similarly, a direct relationship was found between the content of Cu in soils with the Cu level in PM₁₀ atmospheric particles. The origin was attributed to dry and wet atmospheric deposition processes.     

Fingerprinting of Crude Oils for Pollution Control

Abstract

Total, demetallated porphyrins from selected “export” and “weathered” crude oils were analyzed by high performance liquid chromatography (HPLC). The aim was to study the effect, if any, of oil weathering processes on the type and distribution of these compounds and hence, assess the applicability of their HPLC fingerprints in the area of pollution control. The results revealed that petroporphyrins are not readily susceptible to natural weathering processes and that their HPLC fingerprints may be applied to crude oil classification and could supplement other techniques of identifying oil pollutants.     

Organic Compounds in Surface and Deep Antarctic Snow

Abstract

Eight surface snow samples taken during the 1987/88, 1988/89 and 1990/91 Italian Antarctic Expeditions and six samples collected at different depths from two dissimilar sites during the 1990/91 Expedition, were analyzed for the non-chlorinated organic content using the GC capillary columns technique and GC-MS. Several biogenic and anthropogenic classes of organic compounds were identified and quantitatively determined. The data obtained give a more complete picture of the pollution level in Antarctica.     

Chemometric characterization of gamma irradiated chestnuts from Turkey

Chestnut (Castanea sativa Miller) is a valuable natural resource, with high exportation levels. Due to their water content, chestnuts are susceptible to storage problems like dehydration or development of insects and microorganisms. Irradiation has been revealing interesting features to be considered as an alternative conservation technology, increasing food products shelf-life. Any conservation methodology should have a wide application range. Hence, and after evaluating Portuguese cultivars, the assessment of irradiation effects in foreign cultivars might act as an important indicator of the versatility of this technology. In this work, the effects of gamma irradiation (0.0, 0.5 and 3.0 kGy) on proximate composition, sugars, fatty acids (FA) and tocopherols composition of Turkish chestnuts stored at 4 °C for different periods (0, 15 and 30 days) were evaluated. Regarding proximate composition, the storage time (ST) had higher influence than the irradiation dose (ID), especially on fat, ash, carbohydrates and energetic value. Sucrose exhibited similar behavior in response to the assayed ST and ID. The prevalence of ST influence was also verified for FA, tocopherols and sucrose. Lauric, palmitoleic and linolenic acids were the only FA that underwent some differences with ID. Saturated, monounsaturated and polyunsaturated fatty acids levels were not affected either by storage or irradiation. α-Tocopherol was the only vitamer with significant differences among the assayed ST and ID. Overall, Turkish cultivars showed a compositional profile closely related with Portuguese cultivars, and seemed to confirm that gamma irradiation in the applied doses did not change chestnut chemical and nutritional composition.     

Overview on multicomponent ceramic composite materials used for efficient photocatalysis – An update

Water is an important item for the survival of humans, animals and plants in the planet earth. In the industrialized world, water pollution is raising every day, mainly in the textile, paper, medicine, and plastic production industries. Pollution from coloured compounds is primarily identified as being the major threat to wastewater. In the absence of any pre-treatment, substituted phenols, dyes and agricultural wastes seriously contaminate groundwater systems. For the removal of dyes from the industrial waste water, the following three traditional methods are used: chemical, physical and biological but, the cost of the methods little high. For alternation of these methods, now a days photocatalytic degradation method was used. Metal and metal oxide nanoparticles are excellent catalysts for reducing and degrading aqueous phase nitro compounds and aromatic dyes. Nanoparticles are commonly assembled into two types, i.e., organic (carbon nanoparticles) and inorganic (metal, semiconductor and magnetic nanoparticles) nanoparticles. In this review article we are mainly focused on the behaviour of different types of pure metal oxides and metal oxide@metal/metal oxide/carbon/polymer nanocomposites for the removal of various organic pollutants from water and their efficiency has been reported. As a result of their review the cerium-based metal oxides such as CdS/CeO₂, CeO₂/Y₂O₃, GQDs/CeO₂ and Ag/cellulose@CeO₂/QDs shows more degradation efficiency (above~95%) towards the organic pollutants when compared to other metal oxides.     

Vertical Mobility of Soil Contaminants: Preliminary Results of a Survey on the Herbicide Atrazine

Abstract

Atrazine is considered a potential contaminant of water bodies, where it has been repeatedly detected. Its use in Italy is almost limited to the Northern part of the country where corn monocultures are common. Northern Italy is characterized by the presence of an area with soil quite permeable and where ground waters are often present at not very deep levels. In this area well waters, which represent the main source of drinking water, have been frequently found contaminated by atrazine. A program has been started aimed at studying the role of soil nature and local factors in the process of groundwater contamination. Two atrazine application rates were used at two sites with loamy and loamy-sandy soils. Results clearly show a different mobility of atrazine in the two soil types. Since the two sites have similar organic carbon levels, the major proportion of clay to sand and the lower pH of loamy soil may explain the lower vertical mobility of atrazine in this soil. Work is in progress to study atrazine behaviour to a soil depth of 30cm and the effect of repeated atrazine applications on ground water pollution.     

Source Apportionment of Ambient PM10 in the Urban Area of Longyan City,China: a Comparative Study Based on Chemical Mass Balance Model and Factor Analysis Method

In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night amb...     

Determination of the orientational ordering of 4′-cyanophenyl-4-alkylbenzoates by 13C NMR

Abstract

The orientational ordering of three 4′-cyanophenyl-4-alkylbenzoates (with number of carbons in the alkyl chain, n = 6,7 and 8; hereafter abbreviated as n-CPBs) has been investigated by ¹³C NMR. The order parameters of different molecular segments in the nematic phase of the n-CPBs were determined by the two-dimensional technique of separated local field (SLF) spectroscopy combined with off-magic-axis, variable-angle spinning (VAS) of the sample. The carbon-13 chemical shifts for each carbon nucleus in these compounds were determined by slowly spinning the sample parallel to the applied magnetic field. The order parameters obtained from SLF/VAS studies are linearly related to the corresponding anisotropic carbon-13 chemical shifts. These results provide a convenient way to obtain the order parameters for other homologous members of this liquid crystal series by direct measurement of only their carbon-13 chemical shifts in conjunction with the observed linear relationship between order parameters and chemical shifts.     

Radiation Curing of Coatings

Abstract

Printing inks, paints, and other coatings are applied as a liquid or paste but must change to a solid and nontacky state before the painted or coated article can be used. The change is known as curing or drying. Sometimes it occurs by physical means, the evaporation of a solvent or dispersion medium for example, and sometimes by chemical changes such as polymerization and cross-linking. These chemical processes connect the many relatively small molecules of the original liquid or paste into a large molecular network or insoluble solid, which may be either rigid or rubbery in consistency depending upon the requirements of a particular application. Among traditional materials, gravure inks and many lacquers dry by solvent evaporation while paints and inks based upon linseed oil “dry” by chemical cross-linking promoted by oxygen in the air. Considerable time is usually required for curing in both methods, and the evaporation of solvents can result in air pollution and potential fire hazards. There is also a tendency of the media to dry upon presses, brushes, sprayers, and other application equipment. The long cure time requirement raises difficulties in modern production lines; the other factors have become more acute since the rapid rise of petroleum prices and the advent of air pollution legislation.     

Source apportionment of groundwater pollutants in Apulian agricultural sites using multivariate statistical analyses: case study of Foggia province

Background

Ground waters are an important resource of water supply for human health and activities. Groundwater uses and applications are often related to its composition, which is increasingly influenced by human activities.In fact the water quality of groundwater is affected by many factors including precipitation, surface runoff, groundwater flow, and the characteristics of the catchment area. During the years 2004-2007 the Agricultural and Food Authority of Apulia Region has implemented the project “Expansion of regional agro-meteorological network” in order to assess, monitor and manage of regional groundwater quality. The total wells monitored during this activity amounted to 473, and the water samples analyzed were 1021. This resulted in a huge and complex data matrix comprised of a large number of physical-chemical parameters, which are often difficult to interpret and draw meaningful conclusions. The application of different multivariate statistical techniques such as Cluster Analysis (CA), Principal Component Analysis (PCA), Absolute Principal Component Scores (APCS) for interpretation of the complex databases offers a better understanding of water quality in the study region.

Results

Form results obtained by Principal Component and Cluster Analysis applied to data set of Foggia province it’s evident that some sampling sites investigated show dissimilarities, mostly due to the location of the site, the land use and management techniques and groundwater overuse. By APCS method it’s been possible to identify three pollutant sources: Agricultural pollution 1 due to fertilizer applications, Agricultural pollution 2 due to microelements for agriculture and groundwater overuse and a third source that can be identified as soil run off and rock tracer mining.

Conclusions

Multivariate statistical methods represent a valid tool to understand complex nature of groundwater quality issues, determine priorities in the use of ground waters as irrigation water and suggest interactions between land use and irrigation water quality.

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Evaluation of VOCs Emitted from Biomass Combustion in a Small CHP Plant: Difference between Dry and Wet Poplar Woodchips

The combustion of biomass is a process that is increasingly used for the generation of heat and energy through different types of wood and agricultural waste. The emissions generated by the combustion of biomass include different kinds of macro- and micropollutants whose formation and concentration varies according to the physical and chemical characteristics of the biomass, the combustion conditions, the plants, and the operational parameters of the process. The aim of this work is to evaluate the effect of biomass moisture content on the formation of volatile organic compounds (VOCs) during the combustion process. Wet and dry poplar chips, with a moisture content of 43.30% and 15.00%, respectively, were used in a cogeneration plant based on a mobile grate furnace. Stack’s emissions were sampled through adsorbent tubes and subsequently analyzed by thermal desorption coupled with the GC/MS. The data obtained showed that, depending on the moisture content of the starting matrix, which inevitably influences the quality of combustion, there is significant variation in the production of VOCs.     

Understanding Variations in Pollution Levels of Marine Biota: The Particle Concentration Effect

Abstract

Important seasonal variations in contamination levels of marine biota by lipophile organic compounds are noted when overviewing pollution data, even when data are normalized on lipid content. We therefore tried to understand part of the observed variations in contamination levels between watermasses (different geographic areas or seasons) by studying lipophile pollutant bioconcentration at the origin of the food chain.

The uptake kinetics and bioconcentration of ¹⁴C-DDT, by five species of marine phytoplankton were investigated in laboratory experiments. An inverse relationship, representative for all species studied, was noted between the phytoplankton bioconcentration factor and the phytoplankton biomass (both normalized on organic carbon). No differences in bioconcentration factors among different phytoplankton species, with different cell sizes and biochemical characteristics, were noted, when data were standardized on organic carbon content. The importance of the Particle Concentration Effect (PCE) on the bioconcentration factor of micro-organic pollutants is, in this study, further illustrated with data on pollution of North Sea field samples. It is shown that within a specific range of organic matter, normalization of pollution data on particulate or phytoplankton biomass will account for part of the geographic and seasonal differences in organochlorine contamination levels noted for marine watermasses.     

Comparison of ESI‐MS/MS and APCI‐MS methods for the quantification of folic acid analogs in C. elegans

Folic acid (FA) plays a vital role in central metabolism, including the one carbon cycle, nucleotide, and amino acid biosynthesis. The development of sensitive, accurate analytical methods to measure FA intermediates in tissues is critical to understand their biological roles in diverse physiological and pathological contexts. Here, we developed a highly sensitive method for the simultaneous quantification of FA intermediates in the nematode Caenorhabditis elegans as a model to dissect metabolic networks. The method was further validated by analyzing the worm folate pool upon RNAi knockdown of the dihydrofolate reductase gene dhfr‐1. Comparative mass spectrometry behavior of the FA analogs using two different ion sources, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), revealed ESI‐MS/MS to be more sensitive, but APCI‐MS provided more detailed structure inferences, which can elucidate chemical investigation and synthesis of FA analogs. Finally, we report on the use of in vitro oxidation coupled with high‐resolution mass spectrometry as a tool to discover new endogenous FA derivatives in the nematode.     

An attempt to separate A → B process spectra. SEparation by MInimum overLApping Method SEMILAM

It is of particular importance to characterise spectrally each component in the chemical systems in which the reaction proceeds or when the two forms of the same compound exist in equilibrium (tautomerism, cis-trans isomerism, dissociation, etc.). Moreover, physical or chemical separation of the component that is in a smaller amount is always difficult, as well as recording its spectrum. A new simple numerical method of extraction of overlapped spectra of two components is presented. It was termed SEMILAM, which stands for ‘separation by minimum overlapping method’. This method can be applied when two spectra of the same sample consisting of two species can be recorded. These spectra have to differ in composition but total concentration has to maintain constant. In other words, the data required to apply the method comes from one sample for which the two spectra were recorded at two different points of time (the composition of the sample has to change). Knowledge of real fractions found in the crude plots is sufficient to extract quantitatively the spectra of pure components. This new simple method was successfully tested on simulated spectra and then applied to a real problem.     

Quantitative determination of sodium perborate and sodium percarbonate in detergent powders by infrared spectrometry

Sodium perborate (SPB) and sodium percarbonate (SPC) are solid compounds which act as sources of H₂O₂ in solution for stain bleaching, being considered as oxidizing agents in washing powder. This research deals with the quantitative determination of SPB and SPC by an analytical procedure based on attenuated total reflectance Fourier transform infrared spectrometry, utilizing partial least squares for data processing in the 1600-800 cm⁻¹ spectral region. The statistical parameters such as R ², standard error of prediction and relative standard deviation have been evaluated, while number of factors, number of scans and resolution were optimized. The standard deviation of method was 0.006 and 0.010 for SPC and SPB, respectively.     

Development of ANFIS technique for estimation of CO2 solubility in amino acids and study on impact of input parameters

ANFIS (Adaptive neuro fuzzy inference system) modeling of CO₂ capture using chemical absorbent was carried out in this study to correlate the solubility of CO₂ to the solvent and operational parameters. In the ANFIS model, the input parameters including temperature, pressure, and physio-chemical properties of the solvent were considered, while the loading of CO₂ in the absorbent was considered as the sole target output to be predicted by the model. Indeed, we developed a machine learning based model for predicting the CO₂ loading capacity in amino acid salt solutions as the chemical absorbent of carbon dioxide. This model uses a metaheuristic optimized ANFIS based on a wide range of amino acids. This study's novel part is the use of Differential Evolution (DE) and Firefly Algorithm (FA) metaheuristics in order to solve hyper-parameter tuning of ANFIS as an optimization problem based on differential evolution. Accordingly, the optimized ANFIS model has an R² score of 0.9520 for the test data and a score of 0.9841 for the training data. This indicates that the proposed model is both general and accurate in terms of its predictions for CO₂ loading in amino acid salt solutions. The MAPE and RMSE error rates are also 1.17E-01, respectively, while the MAPE error rate is 1.14E-01.