MONITORING OF PAHs IN REFINERY EFFLUENTS (original) (raw)
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Environmental Science and Pollution Research, 2009
Background, aim, and scope Polycyclic aromatic hydrocarbons (PAHs) are often found in oily wastewaters. Their presence is usually the result of human activities and has a negative effect on the environment. One important step in addressing this problem is to evaluate the effectiveness of PAH removal by biological processes since these are the most cost-effective treatments known today. Many techniques are presently available for PAH determination in wastewaters. Solid phase microextracion (SPME) is known to be one of the most effective techniques for this purpose. When analyzing complex matrices with substances such as natural organic matter (NOM) and non-aqueous phase liquids (NAPL), it is important to differentiate the free dissolved PAH from matrix-bonded PAH. PAHs associated with the bonded fraction are less susceptible to biological treatment. The present study concerns the development of a simple and suitable methodology for the determination of the freely dissolved and the total fraction of PAHs present in oily wastewaters. The methodology was then applied to an oily wastewater from a fuel station retention basin. Material and methods Headspace SPME was used for analyzing PAH since the presence of a complex or dirty matrix in direct contact with the fiber may damage it. Four model PAHs—anthracene, fluorene, phenanthrene, and pyrene—were analyzed by GC-MS. Negligible depletion SPME technique was used to determine the free fraction. Total PAH was determined by enhancing the mass transfer from the bonded phase to the freely dissolved phase by temperature optimization and the use of the method of standard additions. The PAH absorption kinetics were determined in order to define the optimal sampling conditions for this method. The fitting of the experimental data to a mathematical model was accomplished using Berkeley Madonna software. Humic acid and silicon oil were used as model NOM and NAPL, respectively, to study the effect of these compounds on the decrease of SPME response. Then, the method was evaluated with wastewater from a fuel station spill retention basin. Results The SPME kinetic parameters—k 1 (uptake rate), k 2 (desorption rate), and K SPME (partition coefficient)—were determined from experimental data modeling. The determination of the free fraction required 15-min sampling to ensure that PAH depletion from sample was below 1%. For total PAH, a 30-min extraction at 100°C ensured the maximum signal response in the GC-MS. For the determination of free and total PAHs, extractions were performed before reaching the SPME equilibrium. The wastewater used in this study had no free fraction of the analyzed PAHs. However, the four studied PAHs were found when the method for total PAH was used. Discussion The addition of NOM and NAPL dramatically decreased the efficiency of the SPME. This decrease was the result of a greater partition of the PAHs to the NAPL and NOM phases. This fact was also observed in the analysis of the fuel station spill retention basin, where no free PAH was measured. However, using the method of standard addition for the determination of total PAH, it was possible to quantify all four PAHs. Conclusions The method developed in the present study was found to be adequate to differentiate between free and total PAH present in oily wastewater. It was determined that the presence of NOM and NAPL had a negative effect on SPME efficiency. Recommendations and perspectives The presence of binding substances had a great influence on SPME kinetics. Therefore, it is of extreme importance to determine their degree of interference when analyzing oily wastewaters or results can otherwise be erroneous. Other factors influencing the total PAH determinations should be considered in further studies.
Method Validation for SPE Applied to Determination of PAH in Petroliferous Industry Effluent Water
American Journal of Analytical Chemistry, 2011
The presence of polycyclic aromatic hydrocarbons (PAH) in produced water is of environmental concern due to their toxic properties. PAH analysis in complex samples requires pre-treatment to enrich the fraction containing analytes, and eliminate matrix interferences. The objective of this work was to develop and validate an analytical methodology for determination of PAH in produced water, using solid phase extraction (SPE) and analysis by gas chromatography with flame ionization detection (GC-FID). Average recoveries of PAH from produced water enriched at two concentration levels varied from 30.9% for naphthalene to 119.1% for chrysene (RSD between 3.8% and 22.2%). The linear range was between 0.5 and 50.0 µg·mL -1 , with regression coefficients better than 0.998. Detection limits were between 0.01 and 0.04 µg·L -1 , and quantitation limits were between 0.05 and 0.16 µg·L -1 . The validated method was applied to samples of produced water treated for disposal, in which concentrations varied from 3.5 µg·L -1 for phenanthrene to 44.3 µg·L -1 for naphthalene ( = 177.7 μg·L -1 ). The method was also applied to seawater samples, in which 13 PAH compounds were detected ( PAH PAH = 60.27 μg·L -1 ), probably derived from pyrogenic sources.
Foods
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental and processing contaminants generated by both spontaneous and anthropogenic incomplete combustion processes of organic matter. Contamination of PAHs in vegetable oils can result from several factors and processes, including environmental contamination, oil processing, and migration from food contact materials. The determination of PAHs in edible oil presents a challenge because of the complexity of the matrix. Since PAHs are present at lower levels than triglycerides, it is necessary to isolate the compounds of interest from the rest of the matrix. To this purpose, a new purification approach based on a double solid-phase extraction (SPE) step followed by high performance liquid chromatography–fluorometric detector (HPLC-FLD) analysis was developed. The method involves a first purification step by using a 5 g silica SPE cartridge, previously washed with dichloromethane (20 mL), dried completely, and then conditione...
Soil & Sediment Contamination, 2011
Petroleum products are one of the major sources of energy for industry and daily life. Growth of the petroleum industry and shipping of petroleum products has resulted in the pollution. Populations living in the vicinity of oil refinery waste sites may be at greater risk of potential exposure to polycyclic aromatic hydrocarbons (PAH) through inhalation, ingestion, and direct contact with contaminated media. PAH have often been found to coexist with environmental pollutants including heavy metals due to similar pollution sources. The levels and distribution patterns of Σ16 PAH (sum of the 16 PAH) and heavy metals (lead, copper, nickel, cobalt, and chromium) were determined in soil and sediment in the vicinity (5 km radius) of an oil refinery in India. Concentrations of Σ16 PAH in the soils and sediments were found to be 60.36 and 241.23 ppm, respectively. Higher amount of PAH in sediments as compared to soil is due to low water solubility of PAH, settled in the bottom of aquatic bodies. The levels of lead, copper, nickel, cobalt, and chromium (total) in soil were 12.52, 13.52, 18.78, 4.84, and 8.29 ppm, while the concentrations of these metals in sediments were 16.38, 47.88, 50.15, 7.07, and 13.25 ppm, respectively. Molecular diagnostics indices of PAH (Ratio of Phenanthrene/Anthracene, Fluranthene/Pyrene) calculated for soil and sediment samples indicate that the oil refinery environment is contaminated with PAH from petrogenic as well as pyrolytic origin and heavy vehicular traffic on the Agra- Delhi National highway. Sixteen PAH priority pollutants were detected in the United States in entire samples collected near oil refinery areas and concentrations of Σ16 PAH in soil was found to be 1.20 times higher than the threshold value for PAH in soil by ICRCL (Inter-Departmental Committee on the Redevelopment of Contaminated Land). This concentration could lead to disastrous consequences for the biotic and abiotic components of the ecosystem and may affect the soil quality, thus impairing plant growth and its bioaccumulation in food chain.
2015
Polycyclic Aromatic Hydrocarbons (PAHs), which arise from incomplete combustion during engine operation, escape the combustion chamber, leading to lubricant contamination. PAHs have been declared highly detrimental to living organisms, and thus, PAH regulation in the environment is crucial because used engine oil accumulates PAHs in high levels. Engine oil samples were collected at different car maintenance workshops around Johannesburg, where the analysis of 5 target PAHs was carried out in both fresh and used engine oil samples (different oil bands), and then subjected to Gas Chromatography-Mass Spectrometry (GC/MS) and High Performance Liquid Chromatography (HPLC). In contrast to preliminary studies reporting higher PAH values of 300+ in used engine oil, the PAH value has decreased significantly, with PAH content being 70 and 7 times more in used engine oil by HPLC and GCMS respectively due to the different capabilities of the two instruments. Fourier Transform Infrared (FTIR) revealed evidence showing the formation of PAHs, which was corroborated by the presence of a band at 1600 cm-1 , which is associated with a CC stretch in a ring. In comparison to fresh oil, used oil quantitative proton Nuclear Magnetic Resonance (NMR) revealed a new intense peak at the aromatic region between 7-7.5 ppm, which may have arisen due to PAH formation. It was also observed that the PAH content was considerably lower compared to other constituents found in the oil sample. This drastic reduction in PAH concentration, may be due to the significant improvements made in lubricating (engine) oil formulations, refining processes, and engine designs. iii DEDICATION In memory of the fallen soldiers belonging to squad: Shakoane, Khumalo, Monareng and Mashego I would also like to extend my gratitude to the Chemical Industries Education and Training Authority (CHIETA) for funding both my research and coursework, the School of Chemistry and School of Chemical and Metallurgical engineering for their support and permission to use their facilities for analysis. I would also like to thank the personnel that took part to see through this study namely
Statistical investigations on PAH concentrations at industrial sampling site
2011
Human exposure to combustion emissions including the associated airborne fine particles and mutagenic constituents have been studied in populations in different countries. PAH compounds are generated by combustion of organic matter in mobile sources as well as in stationary sources; they play a major role in defining the overall toxicity of atmospheric particulate matter (PM) although they are negligible in the total mass of the PM. The aim of this work was to apply statistical investigations on PAH concentrations measured at industrial sampling site in Taranto (Apulia Region, South of Italy) from
SPE Annual Caspian Technical Conference and Exhibition, 2014
Indicator ratios of the concentrations of polycyclic aromatic hydrocarbons (PAH) are wide used to determine the sources of the hydrocarbon pollutions. These estimations are used for identification of sources of PAH itself as well as of the pollutions that satellites they are (products of every combustion processes and oil pollutions). The necessity of assessments is connected with the problems of identification of the causes of the environmental damages as a result of pollution of the environments. The indicator ratios of PAH are considered as a "geochemical markers" that are used to determine the sources of the pollutants. This research is based on the multiple literature data about the PAH concentrations in natural and man-made objects. The main purpose of this research is to analyze the accuracy of the received assessments and the assessment of the possibility to use the identified of the foreign researches. Critical values of the indicator ratios in the natural conditi...
Microchemical Journal, 2018
A gas chromatographic coupled to a triple quadrupole tandem mass spectrometric (GC-MS/MS) method was optimized in order to measure the levels of polycyclic aromatic hydrocarbons (PAHs) in different non industrial indoor environments using active (filter + XAD-2) and passive (polyurethane, PUF) samplers. Ultrasonic and soxhlet extractions were used for active and passive samplers, respectively. The precision and accuracy of the analytical methods used were tested by spiking PUF, filters and XAD-2 with different working standards containing all analyzed PAH compounds. The proposed methods were applied to the analysis of real samples collected in the urban area of Ciudad Real, Spain. Nineteen PAHs were investigated in homes and workplaces such as petrol station stores (PSS), an underground parking office and the office of a periodic technical inspection of vehicles (PTI). The range of individual concentrations of PAH collected with the active sampler was from non detected to 144 ng m −3 at home, from < LOD to 595 ng m −3 at PSS, from 0.08 to 492 ng m −3 at parking office and from non detected to 93 ng m −3 at PTI office. Passive samplers were only employed at homes and the concentration range of PAH was from non detected to 5.1 ng m −3. Naphthalene was the most abundant PAH in all samples using active samplers while phenanthrene was the most abundant at homes using passive samplers. Total concentrations of measured PAH (ΣPAH) were as follow: 283 ng m −3 (home), 217-911 ng m −3 (PSS), 732 ng m −3 (parking office) and 216 ng m −3 (PTI office). Three components were extracted from the application of PCA to the petrol stations stores accounting for 97.2% of the total variance. A procedure to estimate the measurement uncertainty of PAH collected with active samplers has also been developed as it is an important issue in order to achieve accurate measurement results. The relative uncertainties were found to be in the range of 16-45% except for Acenaphthene whose uncertainty was around 54%.