Polycyclic Aromatic Hydrocarbons In Wastewater Research Articles

Nanoscale zero-valent iron (NZVI) intercalated MXene (Ti3C2Tx) for removal of polycyclic aromatic hydrocarbons in wastewater

MXenes are promising candidates for the removal of pollutants from aqueous solutions. Their application, however, is restricted by the lack of surface-active sites. This study examined the effect of NZVI intercalated MXene on the removal of polycyclic aromatic hydrocarbons from wastewater. XPS spectra, FTIR analysis, SEM images, and N2 adsorption-desorption isotherms characterizations indicated that the functional groups on the MXene surface aided in the introduction and stabilization of NZVI into the inter-layer and surface of MXene. The adsorption parameters (pH, dosage and contact time) were optimized using response surface methodology (RSM) in design expert software. The optimum operating conditions for the removal of naphthalene, fluorene and phenanthrene using NZVI intercalated MXene (named N-MXene-3) were pH of 3, dosage of 101.5 mg/L and contact time of 40.5 min. The use of synthesized N-MXene-3 to extract naphthalene, fluorene, and phenanthrene from oil and gas industry wastewater samples validates the usefulness of the proposed method in testing actual wastewater samples. Over 80% of the three polycyclic aromatic hydrocarbons in wastewater were removed by the adsorbent. N-MXene-3 was shown to be an effective, and promising material for wastewater treatment.

Monitoring of polycyclic aromatic hydrocarbons in wastewater of industrial city, Riyadh region, Saudi Arabia

Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons with more than two benzene rings in their molecules and are a class of harmful organic pollutants widely distributed in nature. This research aims to determine the Polycyclic Aromatic Hydrocarbons (PAHs (Naphthalene, Anthracene, and Chrysene (2, 3, and 4 Rings respectively) in different sources of treated and untreated wastewater collected from different sources during the years of 2021 and 2022. Eleven wastewater sources were collected from different industrial treated wastewater, farms, main treatment plants, tanning factory treated wastewater, tanning factory non-treated wastewater, Carton factories, Factories Lake, and Grease refining plants. PAHs were extracted by QuEChERS methodology and Analyzed by GCMSMS/TQD. The results of PAHs concertation in wastewater ranged from 19.55 -278.29 µg/l for Naphthalene, 21.09 -223.69 µg/l for Anthracene, and 14.05-123.11 for Chrysene. Tanning factory non-treated wastewater had the highest concentration of examined 3 PAHs. Results showed also the highest PAHs concentrations was in tanning factory non-treated wastewater, followed by carton factories, tanning factory treated wastewater, Grease refining plants, Factories Lake, and then the main treatment plant. These outcomes of this study can be used to deliver significant guidelines concerning habitants of the area for possible measures for controlling PAHs contamination in Riyadh industrial city to protect human health and ensure environmental and wastewater sustainability.

Assessment of Total Petroleum Hydrocarbons and Polycyclic Aromatic Hydrocarbons in Wastewater from Selected Flow Stations in Agbada II, Rivers State

Aims: This study evaluates total petroleum hydrocarbon (TPH) and polycyclic hydrocarbons (PAHs) concentrations in wastewaters from three locations of the oil-producing flow station in Rivers State.
 Study Design: By experiment and the results obtained by analytical means.
 Place and Duration of Study: This work was conducted at the Department of Industrial Chemistry/Petrochemical Technology, School of Science and Laboratory Technology, University of Port Harcourt, Choba, Rivers State, Nigeria between February and August, 2021.
 Methodology: The evaluation was done using gas chromatography-Flame Ionization Detector (GC-FID), and Gas Chromatography-Mass Spectrometer Detector (GC-MSD).
 Results: Results obtained showed low levels of total petroleum hydrocarbons ranging from 0.051, 0.119, and 0.07 mg/l and 0.01, 0.06, and < 0.01 mg/l for polycyclic aromatic hydrocarbons for the three locations, respectively. The results also revealed that the concentrations of the total petroleum hydrocarbons of the samples from the three locations were highest at carbon atom 17 suggesting a biogenic contribution of organic matter. The chromatographs obtained gave evidence that the nature of the contamination was minimally crude oil, because crude oil normally distributes in broad range, as observed in the locations samples as against the narrower carbon range of C8 to C40 characteristics of refined products. The pristane/phytane ratios, which were 0.925, 0.891 and 0.372 for the three samples, depicted an oxygenated environment. The C17/pristane ratios (39.53, 38.93, and 31.48) for all three locations revealed that the wastewaters were slightly weathered. The low concentrations as well as absence of high molecular weight polycyclic aromatic hydrocarbons and higher concentrations of low molecular weight polycyclic aromatic hydrocarbons support the petrogenity of the wastewaters. 
 The phenanthrene/anthracene ratios (1.26, 0, and 0) for the three samples confirm the nature of the wastewaters. In addition, the absence of benzo(a)anthracene to chrysene ratio for all three samples point to proper treatment of the wastewaters.
 Conclusion: From this study, the level of total petroleum hydrocarbons (TPH) and polycyclic hydrocarbons (PAHs) obtained from all the samples were lower than the maximum recommended levels by the Department of Petroleum Resources (DPR). This study recommends constant monitoring in the total petroleum hydrocarbons and polycyclic hydrocarbons concentrations because even at its low concentrations can be injurious to health of the people residing within the facility and beyond.

The influence of UV irradiation on PAHs in wastewater

Studies were carried out on the impact of UV radiation contact time and UV/chlorination processes on changes in polycyclic aromatic hydrocarbons (PAHs) content in treated wastewater in order to obtain environmentally safe water. The research showed that the optimal time of UV irradiation for both processes was 30 min. After irradiation, the total concentration of PAH decreased by 66%, and after the UV/chlorination process by 78%. Following UV irradiation, the reduction ranged from 74% to 81% for 3-ring PAHs, 4-ring benzo(a)anthracene and 5-ring dibenzo(a,h)anthracene. Using the UV/chlorination process, the greatest changes were observed for acenaphthene (93 ± 4%), anthracene (90 ± 4%), pyrene (87% ± 3) and acenaphthylene (83 ± 4%). Due to limited information on the mechanisms which can be responsible for the observed decrease in PAH content in wastewater after the UV and UV/chlorination processes, it cannot be clearly stated to what extent the methods used affect the actual reduction of the concentration, therefore further research is required.

Chemical industrial kilns used for co-processing of hazardous waste: Low environmental risks of polycyclic aromatic hydrocarbons (PAHs)

Chemical industrial kilns were found to be used for waste treatment, however it is still in the research stage. In our study, field tests were conducted to find the emission and distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) during co-processing of hazardous waste in an industrial scale coal-water slurry gasifier (CWSG), which is applied to ammonia production. Changes of temperature, pressure and gas production of CWSG were recorded under both blank condition (i.e., regular production) and test condition (i.e., feedstock mixed with hazardous waste). Concentration of PAHs in all the solid waste, waste water, and exhaust gas under two conditions were analyzed. Results showed that co-processing of hazardous waste has little impact on the operation stability of CWSG, the temperature were ranged at 1330–1350 ℃ in CWSG, the pressure and gas production were stabled at 1.0–1.3 MPa and 12,000–14,000 Nm3/h respectively. Low environmental risks of PAHs in regular production and weren’t increased by the addition of hazardous waste. Distribution trends of PAHs with different molecular weights in solid-liquid-gas three phases were basically the same under both two conditions. 92.96 %−93.68 % low molecular weights (LMW, 2–3rings) PAHs distributed in exhaust gas, 50.84 %−71.66 % middle molecular weights (MMW, 4 rings) PAHs distributed in solid waste, and 85.3 %−86.77 % high molecular weight (HMW, 5–6 rings) PAHs distributed in solid waste, while the content of PAHs in waste water was generally low.

Graphene/sepiolite mixtures as dispersive solid-phase extraction sorbents for the anaysis of polycyclic aromatic hydrocarbons in wastewater using surfactant aqueous solutions for desorption

Different graphene/sepiolite (G/Sep) solid mixtures have been prepared and tested as nanometric sorbents for the analysis of polycyclic aromatic hydrocarbons (PAHs) using dispersive solid phase extraction (dSPE) and aqueous solutions of surfactants as environmentally friendly agents for desorption. Quantification of the PAHs was carried out by reversed-phase liquid chromatography (RP-HPLC) with fluorescence detection. The adsorption of four PAHs with increasing number of benzene rings into a G/Sep mixture (2/98, w/w) was investigated. A 100% retention was attained for phenanthrene (Phe), pyrene (Pyr) and benzo(a)pyrene (BaP), while for naphthalene (Nap) the maximum retention was close to 75%. The G/Sep mixtures can be used to remove the PAHs from wastewater. The desorption step was carried out using an aqueous surfactant solution: 100 mM non-ionic polyoxiethylen-23-lauryl eter (Brij L23). Considering the whole extraction process, the highest PAH recoveries (50, 92, 83 and 76% for Nap, Phe, Pyr and BaP, respectively) were obtained using 100 mM Brij L23. The developed method shows very high sensitivity, robustness and precision, as well as low limits of detection and quantification, and has been successfully applied to the analysis of PAHs in wastewater samples.

The fate and enhanced removal of polycyclic aromatic hydrocarbons in wastewater and sludge treatment system: A review

As wastewater treatment plant (WWTP) is considered as an important discharge source of polycyclic aromatic hydrocarbons (PAHs) into the environment, many investigations have been carried out to study the behaviors of PAHs in WWTPs. This review focuses on the fate and enhanced removal of PAHs in wastewater and sludge treatment and disposal processes. Firstly, it is found that the occurrence of PAHs in wastewater and sludge depends on the local industrialization and standard. Low-molecular-weight (LMW) PAHs are dominant in wastewater while high-molecular-weight (HMW) ones are dominant in sludge. Then, the fate of PAHs in different treatment processes are discussed in detail. LMW PAHs can be biodegraded by microorganisms while HMW ones are transferred from wastewater to sludge by adsorption. Among sludge treatment techniques, only anaerobic digestion can remove part of PAHs. Compost results in PAHs migratation to other systems, and incineration produces PAHs for incomplete combustion. Also, the enhanced removal strategies of PAHs are reviewed. PAHs removal can be enhanced by increasing their solubility and the activity of microbes, and PAHs generation can be reduced by using Ca-based additives and co-fuel. Finally, the key points for future investigation on PAHs fate and removal in wastewater and sludge treatment are proposed.

Development of a single format membrane assisted solvent extraction-molecularly imprinted polymer technique for extraction of polycyclic aromatic hydrocarbons in wastewater followed by gas chromatography mass spectrometry determination

A technique that combines membrane assisted solvent extraction and molecularly imprinted polymer into a single step format has been successfully developed and evaluated for the extraction of the 16 US-EPA priority polycyclic aromatic hydrocarbons in wastewater samples followed by determination using gas chromatography coupled with time of flight mass spectrometry. The technique involves placing the polymer particles into a hydrophobic polypropylene membrane bag which is in contact with an aqueous donor phase. The technique was optimized for various parameters that include presence of an organic modifier in the donor phase, stirring rate and extraction time. The optimum conditions were 25% of dimethyl sulfoxide as an organic modifier and stirring at 1000 rpm for 120 min. The limits of detection using the technique were in the 0.01–0.45 ng mL−1 range. Linearity values determined in the 10–1 000 ng mL−1 calibration range were all above 0.9972. Extraction efficiencies of the sixt analytes calculated as averages for three spiking concentrations ranged from 62.8 to 96.8% (RSD = 3.1–12.3%). The optimized method was tested for the extraction of polycyclic aromatic hydrocarbons in wastewater samples in the presence of surrogate standards. The developed method showed great reproducibility with inter day repeatability values ranging from 0.6 to 24.9%. The analytes were quantified in the nanogram level showing that the developed technique is a viable alternative in the analysis of trace organic compounds in complex aqueous samples.

Removal of PAHs from coking wastewater during photodegradation process

The results of investigations on the efficiency of the removal of polycyclic aromatic hydrocarbons (PAHs) from wastewater exposed to UV radiation are presented. The investigations were carried out using wastewater originating from an industrial treatment plant. Samples of wastewater were exposed to UV rays for 30, 60, and 90 s. After exposition to UV rays, PAHs concentration was determined in the samples. Extraction of PAHs from samples was made with the mixture of: cyclohexane and dichloromethane. The quantitative analysis of PAHs by high performance liquid chromatography with a fluorimetric detector was carried out. After exposition to ultraviolet rays, a decrease in PAHs concentration in the samples was observed. Exposure of wastewater to UV-rays resulted in a decrease in the concentration of PAHs in wastewater from an industrial wastewater treatment plant up to 50%. The efficiency of the removal for individual hydrocarbons was varied as it was in the range of 5–67%. The half-life time of hydrocarbons (without naphthalene) was in the range of 64–123 s under exposition to UV rays.

Determination of Polycyclic Aromatic Hydrocarbons in Wastewater by Single-Drop Microextraction Coupled to Capillary Gas Chromatography

This study describes an analytical method employing capillary gas chromatography (GC) using flame ionization detection (FID) that has been developed for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) in wastewater, including naphthalene, 1-naphthol, 2-naphthol and anthracene. For this purpose, single-drop microextraction (SDME) was applied as a sample preparation technique. The SDME parameters such as types of extractants, volume of the microdroplet size, extraction time, stir rate and immersion depth of needle point were investigated and optimized. The method was linear in the ranges from 2.3 ×10-3to 70.0 μg·mL-1for naphthalene, 1-naphthol and anthracene, and 2.2 ×10-3to 50.0 μg·mL-1for 2-naphthol withR2≥ 0.9990. The SDME procedure allowed efficient recovery of the investigated PAHs ranging between 94 % and 104 % with a relative standard deviation (RSD) ≤4.2 for actual wastewater sampes spiked with 5, 10 and 20 μg·mL-1of PAHs, respectively. These results showed the potential of this technique for PAHs monitoring in wastewater samples. Furthermore, the investigated methods are simple, reliable, reproducible, and not expensive.

Polycyclic aromatic hydrocarbons in wastewater, WWTPs effluents and in the recipient waters of Beijing, China

In this study, surface water samples from the Wenyu River and the North Canal, effluent from major wastewater treatment plants (WWTPs) in Beijing, and wastewater from open sewers that discharge directly into the river system were collected and analyzed for 16 priority USEPA polycyclic aromatic hydrocarbons (PAHs). Concentrations of these 16 PAHs ranged from 193 to 1790 ng/L in river surface waters, 245 to 404 ng/L in WWTP effluents, and 431 to 2860 ng/L in the wastewater from the small sewers. The WWTP effluent was the main contributor of dissolved PAHs to the river, while wastewater from the small sewers contributed both dissolved and suspended particulate matter-associated PAH to the river as indicated by the high dissolved organic carbon and suspended particulate matter contents in the wastewater. Although the flow from each open sewer was small, a PAH discharge as high as 44 kg/year could occur into the river from these types of sewers. This amount was equivalent to about 22 % of the PAH loads discharged into the North Canal downstream from Beijing, whereas the remainder was mainly released by the major WWTPs in Beijing.

PAHs in wastewater: removal efficiency in a conventional wastewater treatment plant and comparison with model predictions

Polycyclic aromatic hydrocarbons (PAHs) are very hazardous compounds and, owing to their lipophilicity, they can easily cross biological membranes and accumulate inside organisms, causing damage to the genetic material. The scientific interest in PAHs is related to their demonstrated or supposed genotoxicity (cancer-causing characteristics of B[α ]Py and dB[α, h] first suspected in the 1930s). This study tried to detect the presence of PAHs in wastewater and to estimate their removal efficiency in a conventional wastewater treatment plant (Varese Olona). The PAHs’ presence in municipal wastewater sewage system and in the WWTP effluent was determined by a specific analytical campaign, and afterwards a comparison between observed removal efficiency and FATE model (US-EPA) predictions was carried out.

Source apportionment of elevated PAH concentrations in sediments near deep marine outfalls in Esquimalt and Victoria, BC, Canada: Is coal from an 1891 shipwreck the source?

Previous studies have suggested that coal from the 1891 shipwreck of a collier off Victoria, BC, Canada is responsible for elevated parent (unsubstituted) PAH concentrations in sediments near deep marine outfalls from Esquimalt and Victoria in the Strait of Juan de Fuca. To resolve this question, we analysed a comprehensive suite of resolved and unresolved complex mixture (UCM) alkanes, tricyclic terpane, hopane and sterane biomarkers, and parent and alkyl polycyclic aromatic hydrocarbons (PAHs) in samples of coal, wastewater and sediments. Composition patterns, principal components analysis (PCA) models and PAH and biomarker ratios all indicate that coal from the collier does not make a dominant contribution to any sediment sample. Mass balance calculations based on the n-C24 content and 24/4 tetracyclic terpane to 26/3R tricyclic terpane ratio in coal provide a particularly good match between predicted and observed alkyl PAH concentrations for sediments with high alkyl naphthalenes and phenanthrene/anthracenes and low UCM, but the predicted coal contribution substantially underestimates the measured parent PAHs for all sediment samples. Methylbenz[a]anthracene/chrysene profiles for sediments with a dominance of parent PAHs are very close to coal tar, with a marked predominance of methylbenz[a]anthracenes and the possible 10-methylbenz[a]anthracene as a major constituent, while the methylchrysenes predominate in coal. Hence, coal from the collier could account for most alkyl PAHs in the sediments, but dredged sediment containing pyrolised coal waste from a former coal gas plant in Victoria Harbour is a more likely source for the samples with elevated parent PAHs. PAH ratios indicate that these sources are superimposed on combustion PAHs introduced by a combination of atmospheric deposition and delivery via stormwater and the outfalls. Parent PAH distributions also suggest that PAHs in wastewater that originate from oils and soot in liquid fossil fuel combustion are dispersed and degraded, while the larger wood char particles (containing PAHs more protected from degradation) settle closer to the outfalls. Overall, results suggest that PAHs have predominant sources in wood combustion, coal and possibly coke, with a likelihood of much lower bioavailability than would be expected from wastewater dominated by oils and soot from vehicle combustion.

High performance liquid chromatography–tandem mass spectrometry for rapid and sensitive analysis of six polycyclic aromatic hydrocarbons in wastewater

A sensitive and fast method was developed to quantitatively analyse the six polycyclic aromatic hydrocarbons (fluoranthene (FLT), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a] pyrene (Bap), benzo[ghi]perylene (BghiP) and indeno[1,2,3-cd]pyrene (INPY)) by high performance liquid chromatography (UPLC) coupling with tandem mass spectrometry (MS/MS). Chromatographic separation was performed on a Waters Acquity UPLC BEHC18 column (1.7 microm, 2.1 mm x 50 mm). A 0.2 microm precolumn filter was used to protect the analytical column. Mobile phase Awas acetonitrile containing 0.5% toluene. Mobile phase B was water. Linearity of detection was in the range of 1-100 microg L(-1); LOD of 5 PAHs were lower than 0.1 microg L(-1); LOQ were 0.2 microg L(-1) except for benzo[k]fluoranthene. The LOD and the LOQ of benzo[k]fluoranthene were respectively 0.1 microg L(-1) and 0.8 microg L(-1). Wastewater samples collected from two wastewater treatment plants were determined using this method respectively. Recovery of all compounds varied from 67.8 +/- 10.6% to 113.2 +/- 7.2%. In comparison with the existing methods, this rapid method saves time and solvent and improves instrument sample throughput by 2-5 fold.

Partitioning and sources of PAHs in wastewater receiving streams of Tianjin, China

Polycyclic aromatic hydrocarbons (PAHs) partitioning among dissolved phase, suspended particulate matter, pore water, and sediment was studied in one moderately contaminated river (Yongding New River) and two highly contaminated drainage canals (South Drainage Canal and North Drainage Canal) of Tianjin, China. PAHs concentrations in sediment (ranged from 0.2 to 195μg/g) showed positive relations with both total organic carbon contents (ranged from 0.7% to 31.1%, dw) and black carbon contents (ranged from 0.1% to 2.1%, dw) in the sediments. Moreover, most of the measured organic carbon normalized partition coefficients of PAHs in the three streams were 0.76 to 1.54 log units higher than the predicted values. These indicated that strong and nonlinear sorption of PAHs by carbonaceous geosorbents such as black carbon (BC) existed in the streams, and BC was an important part of the carbonaceous particles controlling the partitioning of PAHs in the sediments of this study. PAH component ratio analyses suggested that PAHs in the three streams, effluent samples from wastewater treatment plants, and soil samples by the riverbank had similar main sources, which is coal/petroleum combustion. We suggested the transportation and transformation of both carbonaceous particles and PAHs during wastewater treatment process, surface runoff, etc, should be studied further in order to make decisions on PAHs controlling measures.

Comprehensive analysis of polycyclic aromatic hydrocarbons in wastewater using stir bar sorptive extraction and gas chromatography coupled to tandem mass spectrometry

The objective of this study was the optimization and comparison of two extraction methods for the determination of polycyclic aromatic hydrocarbons (PAHs) in wastewater (WW). A distribution study of the target compounds between the aqueous phase and the suspended particulate matter (SPM) has been performed in order to establish whether the analysis of both phases is necessary. In this sense, the feasibility of stir bar sorptive extraction (SBSE) and solid-phase extraction (SPE) for the determination of 24 PAHs in WW samples has been evaluated. The results demonstrated the suitability of SBSE to perform a comprehensive analysis of liquid samples containing high amounts of SPM, such as in the determination of PAHs in WWs. A gas chromatography triple quadrupole mass spectrometry (GC–QqQ-MS/MS) method has been also optimized for the separation and detection of the target compounds, avoiding the co-elution of some groups of isomers, such as benzo[ b], [ j] and [ k] fluoranthenes and indene[1,2,3- cd]pyrene/dibenz[ a, h]anthracene. For that purpose, a specific capillary column developed for PAH determination was used. The SBSE procedure was validated and adequate parameters (such as recovery, linearity, precision, limits of detection and quantification) were obtained. Finally, the validated method was applied to the analysis of real samples collected from an experimental WW treatment plant, detecting some PAHs at concentrations in the range 0.007–0.022 μg L −1.

Occurrence and distribution of polycyclic aromatic hydrocarbons in the Egyptian aquatic environment

Persistent organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs) are of great concern due to their persistence, bioaccumulation and toxic effects. In this study, water samples were collected during 2007–2008 from two catchment areas that represent two different models of the aquatic environment in Egypt (Rosetta branch as fresh water and El-Moheet drain as untreated/treated waste water). The distribution of 16 PAHs included in the US Environmental Protection Agency's (EPA) priority pollutant list was analyzed by gas chromatography/mass spectrometry (GC/MS). Total PAH concentrations varied from 242 to 732 ng/L in fresh water from the Rosetta branch with a mean value of 408 ng/L; and for waste water the concentrations were in the range 894 to 1979 ng/L with a mean value of 1476 ng/L. The PAH profiles were dominated by low molecular weight PAHs (two- and three-ring components) in all collected water samples. The origin of PAHs in both waste water and fresh water in these study areas may be from oil or sewage contamination. The total PAHs concentrations of untreated waste water decreased along the treatment process by about 30% at the Zenein waste water treatment plant. The levels of PAHs in waste water are relatively high, although lower than locations with known problems.

Determination of priority carcinogenic polycyclic aromatic hydrocarbons in wastewater and surface water by coacervative extraction and liquid chromatography–fluorimetry

The US Environmental Protection Agency (EPA) and the European Union (EU) have set restrictive limits for priority carcinogenic polycyclic aromatic hydrocarbons (CPAHs) in surface waters (EPA 3.8 ng L −1and EU 2–100 ng L −1) in order to protect aquatic life and human health. Currently, methods meeting these sensitivity criteria are not suitable for routine analysis of CPAHs. Here, we present a simple, rapid and low-cost method for the routine monitorization of these pollutants in aquatic environments based on their extraction with coacervates of decanoic acid reverse micelles in the nano- and microscale, and determination by liquid chromatography–fluorimetry (LC–FL). The method involves the stirring of filtered aqueous samples (36 mL) with 4 mL of THF containing 70 mg of decanoic acid for 5 min, its centrifugation for 10 min and the analysis of 20 μL of the resulting coacervate containing the CPAHs by LC/FL. The method is robust, the extractions being independent on salt concentration (up to 1 M), temperature (up to 60 °C) and pH (below 4). Besides, the coacervate prevents the CPAHs from adsorption onto the surface of containers during sample storage. No clean-up steps are necessary and the method is matrix-independent. The quantification and detection limits of the method ranged between 0.4 and 3.5 ng L −1 and 0.1 and 1 ng L −1, respectively, for the seven priority CPAHs. The method has been successfully applied to the determination of these pollutants in raw and treated sewage from three mechanical–biological treatment plants, two rivers and a reservoir with frequent motorized recreational craft activities, all of them located in the South of Spain. Recoveries for spiked samples in the range 2–30 ng L −1 were between 88 and 95% with relative standard deviations from 1 to 7%. CPAHs were present in wastewater influents at concentrations in the range 3.9–37 ng L −1, while the treatment at the WWTPs studied reduced their concentration in their respective effluents in a percentage near 100%. Three CPAHs were present at quantifiable levels in Guadajoz river (1.8–6.6 ng L −1) and six in La Breña reservoir (1.39–4.8 ng L −1).

Determination of polycyclic aromatic hydrocarbons in aqueous samples by microwave assisted headspace solid-phase microextraction and gas chromatography/flame ionization detection

The novel pretreatment technique, microwave-assisted heating coupled to headspace solid-phase microextraction (MA-HS-SPME) has been studied for one-step in situ sample preparation for polycyclic aromatic hydrocarbons (PAHs) in aqueous samples before gas chromatography/flame ionization detection (GC/FID). The PAHs evaporated into headspace with the water by microwave irradiation, and absorbed directly on a SPME fiber in the headspace. After being desorbed from the SPME fiber in the GC injection port, PAHs were analyzed by GC/FID. Parameters affecting extraction efficiency, such as SPME fiber coating, adsorption temperature, microwave power and irradiation time, and desorption conditions were investigated. Experimental results indicated that extraction of 20 mL aqueous sample containing PAHs at optional pH, by microwave irradiation with effective power 145 W for 30 min (the same as the extraction time), and collection with a 65 μm PDMS/DVB fiber at 20 °C circular cooling water to control sampling temperature, resulted in the best extraction efficiency. Optimum desorption of PAHs from the SPME fiber in the GC hot injection port was achieved at 290 °C for 5 min. The method was developed using spiked water sample such as field water with a range of 0.1–200 μg/L PAHs. Detection limits varied from 0.03 to 1.0 μg/L for different PAHs based on S/N = 3 and the relative standard deviations for repeatability were <13%. A real sample was collected from the scrubber water of an incineration system. PAHs of two to three rings were measured with concentrations varied from 0.35 to 7.53 μg/L. Recovery was more than 88% and R.S.D. was less than 17%. The proposed method is a simple, rapid, and organic solvent-free procedure for determination of PAHs in wastewater.

Determination of Polycyclic Aromatic Hydrocarbons in Wastewater, Sediments, Sludge and Plants in Karak Province, Jordan

Analysis for sixteen types of Polycyclic Aromatic hydrocarbons (PAHs)from samples of raw and treated wastewater, sediments, sludge andplants growing along treated wastewater way was performed inOctober 1997. The collection sites represent two wastewatertreatment plants (WWTP) receiving different types of wastewaterand one site from disposal of raw wastewater in the city ofKarak in southern Jordan.Wastewater treatment efficiency showed removal of PAHs throughsettling tanks and adsorption on sediments after treatment. Theremoval percentage ranged from 44–100% for individual PAH.PAHs were widely distributed at various levels in rawwastewater, treated wastewater, sludge, sediments and plants.The highest concentration was observed in sludge and the lowestin plants. There was a variation in PAHs concentration betweenthe three investigated sites which was attributed to theefficiency of treatment, period of contact with the wastewater,and the nature of activities. The WWTPs were capable or reducingPAHs contamination in water, up to 40% of the total PAHs byadsorption on sludge and sediments.