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Metal clusters oxide were embedded in an N-doped carbon and used as catalysts for the activation of peroxydisulfate or peroxymonosulfate in the selective oxidation of benzyl alcohol. Quenching tests were done to investigate the reaction mechanism.

Made available in DSpace on 2022-05-01T08:44:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Cellophane film production generates cellulosic residues from scraps, edges, and low-quality films. In this work, cellophane was used as a raw material to produce cellulose acetate (CA). CA was produced through the homogeneous route for 6 to 24 hours producing materials with a degree of substitution (DS) between 2.6 and 2.9. The CA materials were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and viscosity-average molecular weight. DS values (DS > 2.6) indicate the preferential formation of cellulose triacetate, and the reaction time leads to materials with different molecular weight from 32,000 to 121,000 g mol- 1 The TGA and DSC curves allowed obtaining information that, together with other techniques, confirm the formation of cellulose triacetate and the production of a material with a heterogeneous structure. The CA membrane was prepared with CA produced with 14 hours of the reaction intended to control the release rates of acetaminophen (ACP). A dense, seemingly pore-free membrane has been produced, as seen by SEM images, which allows the release of small amounts of ACP. The results were promising in the development of CA membranes for the controlled release of drugs from the chemical modification of cellophane residues. Federal Institute of Education Science and Technology of the Triangulo Mineiro (IFTM) School of Pharmaceutical Science São Paulo State University Department of Biotechnology Araraquara University (UNIARA) Pontal Institute of Exact and Natural Science Federal University of Uberlandia (UFU) Institute of Chemistry Federal University of Uberlândia (UFU) São Paulo State University (UNESP) Institute of Chemistry School of Pharmaceutical Science São Paulo State University São Paulo State University (UNESP) Institute of Chemistry

Semivolatile oxygenated organic compounds (SV-OVOCs) are important atmospheric species, in particular for the production and chemistry of atmospheric particulate matter and related impacts on air quality and climate. In this study, SV-OVOCs were collected in the horizontal plane of the roughness layer over the tropical forest in the central Amazon during the wet season of 2018. A sampler mounted to a copter-type, hovering unmanned aerial vehicle was used. Underlying the collection region, a plateau forest transitioned into a slope forest across several hundred meters. The concentrations of pinonic and pinic acids, which are monoterpene oxidation products, had no statistical difference over the two forests. By comparison, across the study period, differences in the concentration of 2-methyltetrols, which are products of isoprene oxidation, ranged from −70% to +480% over the two forests. The chemical lifetime of 2-methyltetrols in the atmosphere is sufficiently long that heterogeneity in the isoprene emission rate from the two forests followed by atmospheric oxidation does not explain the concentration heterogeneity of 2-methyltetrols. Standing waves and local meteorology also cannot account for the heterogeneity. Of the possibilities considered, the most plausible explanation is the direct emission from the forest of 2-methyltetrols produced through biological processes within the plants. Under this explanation, the rate of direct SV-OVOC emissions should be modulated by forest type and related environmental stressors. Direct emissions of SV-OVOCs should be more broadly considered for constraining and improving models of atmospheric composition, transport, and chemistry over tropical forests.

A general strategy to synthesize mesoporous and macroporous carbon and N-doped mesoporous carbon is presented. The immobilization of cobalt catalysts with dispersed subnanometer particles in mesopo...

Palladium nanoparticles of similar size were deposited on different supports, layers of carbon materials (with and without nitrogen doping) on the surface of a MCF (mesocellular foam) silica. For the generation of the N-doped carbon coatings, three different N sources were used to also investigate a possible influence of the N-doped carbon precursor and thus the structure of the N-doped carbons on their performance as catalyst support. These catalysts were tested for the Suzuki coupling and hydrogenation reactions. For the Suzuki reaction, the carbon coatings showed to increase dramatically the stability of the MCF material. Furthermore, when N-doped carbon coatings were applied, strong improvement of the stability of the catalysts was observed due to an enhanced interaction between metal nanoparticles and the support, preventing metal particle growth. In hydrogenation reactions, the presence of the N-doped carbon coating on the silica support increases the adsorption of aromatic compounds causing an enhancement of the catalytic activity of Pd NPs when compared to the non-doped supports.

This article discusses the possibility of using ultrasonic pulse velocity (UPV) as a performance parameter for concrete design. Experimental values of UPV were determined for 68 mix design of concrete with different types of binders. Portland cements with fly ash, blast furnace and silica fume were investigated. All samples had UPV between 4700 and 5400 m/s. The UPV decreases when the w/b ratio increases, although this behaviour is less evident for concrete with silica fume. Also, the UPV is greater at 91 days for all types of binders, when compared with results at 28 days. This is explained due to the formation of more hydrated products inside the concrete over time and because UPV is more difficult to propagate in the void space. It was possible to correlate the compressive strength with the UPV at 28 days, except for the concrete with silica fume. However, the results of these two tests are difficult to correlate at 91 days for all types of binders. This article has shown that it is possible to include UPV in dosage diagrams for some types of binders. The paper proposes empirical models obtained through numerically analysing the dosage diagrams by means of non-linear regressions for estimating the UPV of concrete. The parameters used in these models are usually present in concrete dosing, such as the quantity of aggregates, water-to-binder ratio, compressive strength, and cement content. The correlation coefficient (R2) between the experimental and the calculated UPV was greater than 0.88. Therefore, the inclusion of a non-destructive testing during the concrete design is encouraged. The UPV monitoring can be performed as many times as necessary without causing damage to the structure.

This article evaluated the possibility of using electrical resistivity as a performance parameter for concrete design. Electrical resistivity calculated by theoretical methods based on laws of Archie, Powers and Mills were compared with experimental values for 33 mix design of concrete with different types of cement. Porosity and tortuosity of samples were measured by means of the test of mercury intrusion porosimetry and values found were consistent with the ones proposed by literature. Good correlations between calculated and experimental resistivity were found, with mean differences below 10%. Results indicate that it is possible to elaborate dosage diagrams including resistivity, resulting in an important advancement for the inclusion of the durability in engineering projects. The paper proposes empirical models for calculating electrical resistivity from parameters usually used in the concrete dosing, such as quantity of aggregates, water/binder ratio, compressive strength and cement content.

The presence of dyes in wastewater streams poses a great challenge for sustainability and brings the need to develop technologies to treat effluent streams. Here, we propose a mixture of high superficial area carbon-based nanomaterial strategy to improve the removal of basic blue 26 (BB26) by blending porous carbon nitride (CN) and graphene oxide (GO). We prepared CN and GO pristine materials, as well the nanocomposites with mass/ratio 30/70, 50/50, and 70/30, and applied them into BB26 uptake. Nanocomposite 50/50 CN/GO was found to be the better adsorbent, and the optimization of the adsorption revealed a fast equilibrium time of 30 min, after sonication for 2 min, nanocomposite 50/50, and BB26 dye loading of 0.1 g/L and 100 mg/L, respectively. The pH variation had great influence on BB26 uptake, and at ultrapure water pH, the dye removal capacity by the composite reached 917.78 mg/g. At pH 2, a remarkable removal efficiency of 3510.10 mg/g was obtained, probably due to electrostatic interactions among protonated amine groups of the dye and negatively charged CN/GO nanocomposite. The results obtained were best fitted to the pseudo-second-order kinetic model and the Dubinin–Radushkevich isotherm. The adsorption process was thermodynamically spontaneous, and physisorption was the main mechanism, which is based on weak electrostatic and π–π interactions. The dye attached to the CN/GO nanocomposite could be removed by washing with ethyl alcohol, and the adsorbent was reused for five consecutive cycles with high BB26 uptake efficiency. The CN/GO nanocomposite ability to remove the BB26 dye was 21 times higher than those reported in the literature, indicating CN/GO composites as potential filtering materials to basic dyes.

In this study, the concentrations of 16 Polycyclic Aromatic Hydrocarbon (PAH), considered priority by US EPA (US Environmental Protection Agency), in fine particulate matter (PM2.5), were determined in a forest reserve and in an urban area in the city of Rio de Janeiro. The PM2.5 samples were collected in the Tijuca Forest (TF) and on the Maracana campus of the State University of Rio de Janeiro (UERJ), using PM2.5 high-volume air samplers, from November 2015 to April 2016. The organic matter was extracted, separated by liquid chromatography, and analyzed by gas chromatography-mass spectrometry (GC-MS). The mean total PAH (excluding naphthalene, acenaphthene, and acenaphthylene) concentrations were 0.46 ± 0.61 ng m−3 and 1.12 ± 0.71 ng m−3 in PM2.5 collected at TF and UERJ, respectively. The diagnostic ratios suggested vehicular sources for both sites with no clear distinction between light and heavy vehicular sources. Cluster and principal component analyses were also used to clarify the possible PAH sources. Simulations of air mass trajectories confirmed the transport of pollutants from the city to the forest. Mutagenicity tests revealed that the PM collected in the UERJ presented mutagenic positive activity, likely for nitro-PAH and amino-PAH, which may be related to vehicular emissions. For the TF, although the forest was impacted by the pollutants, no positive activity was detected. Correlation and cluster analyses showed different PAH distributions for the TF and UERJ sites, which indicates that the TF receives the air masses from the city but is also impacted by local emissions.

The presence of surfactants in aquatic environment is a major public health concern. Recently, several methods have been developed to remove these compounds, among these are the adsorption processes. The great challenge of this technology is to achieve high removal capacities, fast adsorption and efficient adsorbent recoveries. The aim of our study was to synthesize GO and rGO and use them for non-ionic surfactant (TX-100) adsorption in consecutive cycles. Both nanomaterials were synthesized and characterized by several analyses including BET method for superficial area, XRD, Raman Spectroscopy, CP/MAS 13C NMR, TGA, FT-IR, XPS, SEM and TEM microscopies. The optimization of the adsorption process was performed by varying many parameters, including the experiment time, nanomaterials/surfactant ratio, temperature, pH and ultrasound irradiation. GO and rGO showed fast TX-100 adsorption, about 30 min to reach equilibrium. The experiments showed that the pH variation affects the removal efficiency for both nanomaterials with pH 6 being the optimized condition. The pseudo-second order kinetic model showed the best fit to the experimental data for both nanomaterials. The equilibrium data for GO and rGO were fitted to the Fowler-Guggenheim and the Langmuir models, respectively. The rGO was verified as the best adsorbent for TX-100 removal, suggesting that hydrophobic and π-stacking interactions are dominant in the process. Besides the superior adsorption efficiency, rGO formed larger aggregates after TX-100 removal than GO, facilitating its separation from solution. Under optimized conditions, GO and rGO revealed superior removal capacities when compared to others adsorbents (1203 and 1683 mg/g, respectively).

Volatile organic compounds (VOCs) play a central role in atmospheric chemistry. In this work, VOCs in the Botanical Garden of Rio de Janeiro were determined using the TO-15 Method. The park occupies 1,370,000 m2 in the southern area of the city and is next to the Tijuca Forest, which is considered the largest secondary urban forest in the world. The total VOC concentrations ranged from 43.52 to 168.75 µg m−3, depending on the sampling site and dates. In terms of concentration isoprene represented 4 %–14 % of the total VOC masses. The results suggested that the differences in biomass, distance from the street and activities within the park affected the concentrations of VOCs. The ratios of isoprene/aromatic compounds were higher than those determined in other areas of the city, confirming that the atmosphere of this green area has the contribution of other sources. Kinetic and mechanistic reactivities were also evaluated.

In this work, transparent organic–inorganic nanocomposites membranes have been prepared by casting process using carboxymethylcellulose (CMC) as organic matrix and synthetic clay (laponite) as reinforcement inorganic filler. Pristine CMC and CMC-laponite nanocomposites films were prepared using different clay-to-polymer ratios and all the obtained membranes are optically transparent on the UV–vis range. Field emission scanning electron microscopy (FE-SEM) images of the nanocomposite films evidenced a homogeneous dispersion of clay in the polymer matrix. As result, mechanical properties of the membranes are deeply affected by the presence of clay, increasing the Young’s modulus and tensile strength values when clay content is increased. On the other hand, maximum strain values decrease when clay concentration is over 10 wt% in comparison to pristine CMC membrane. Thermal properties of CMC films are also influenced by the presence of clay platelets. The main weight loss step of the nanocomposites is shifted toward higher temperatures when compared to pristine CMC membrane, indicating that laponite particles are capable of protecting the polymer chains from thermal and oxidative decomposition. Water vapor permeability (Pw) trend also reveals a decrease in these values for the nanocomposites when clay concentration is high, achieving its minimum permeability at 17 wt% of clay content (which corresponds a decrease of 42% on Pw value in comparison to pristine CMC membrane).

Made available in DSpace on 2018-12-11T16:46:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-06-01 Eusko Jaurlaritza In this study fabrication and characterization of transparent nanostructured composite films based on cellulose triacetate (CTA) and poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (EPE) triblock copolymer were presented. The effect of the addition of EPE triblock copolymer on the thermal stability, morphology, and mechanical properties of cellulose triacetate films was investigated. The triblock EPE was chosen since PEO blocks interact favorably with CTA, whereas, PPO blocks remain immiscible which provokes a microphase separation. This allows to obtain EPE/CTA composite films with ordered microphase-separated structures where PPO spherical microdomains are well-dispersed in PEO/CTA matrix by simple solvent-evaporation process. During this process, PEO block chains selectively interact with CTA by strong interpolymer hydrogen-bonding while PPO block microseparated. The addition even 40 wt% of EPE leads to nanostructured EPE/CTA composite. The cytotoxicity assay of CTA and EPE/CTA composite films confirm non-toxic character of designed transparent nanostructured composites based on sustainable matrices. ‘Materials + Technologies’ Group (GMT) Department of Chemical and Environmental Engineering Faculty of Engineering University of the Basque Country (UPV/EHU), Plaza Europa 1 Faculty of Engineering Vitoria-Gasteiz University of the Basque Country (UPV/EHU), C/Nieves Cano Laboratory of Photonic Materials Institute of Chemistry Sao Paulo State University (UNESP) Medicinal Chemistry and Regenerative Medicine (QUIMMERA) University Center of Araraquara (UNIARA) Laboratory of Photonic Materials Institute of Chemistry Sao Paulo State University (UNESP)

The aim of this study was to characterize the PM2.5-bound polycyclic aromatic hydrocarbon (PAH) concentrations and their diagnostic ratios in an area impacted by light-duty vehicles fueled by neat ethanol and ethanol-blended gasoline. Samples were collected using a high-volume sampler, extracted, and analyzed for all 16 EPA-priority PAHs using gas chromatography/mass spectrometry (GC/MS) following the EPA 3550B Method. The most abundant PAHs were benzo[g,h,i]perylene, benzo[b]fluoranthene, benzo[a]pyrene and indeno[1,2,3-c,d]pyrene. The total mean concentration was 3.80 ± 2.88 ng m−3, and the contribution of carcinogenic species was 58 ± 16 % of the total PAHs. The cumulative health hazard from the PAH mixture was determined, and the carcinogenic equivalents and mutagenic equivalents were 0.80 ± 0.82 and 1.17 ± 1.04 ng m−3, respectively. Diagnostic ratios and normalized ratios were calculated for the individual samples.

The efficiency of U.S.EPA TO-15 Method was evaluated under typical conditions of an urban environment with natural and anthropic emission sources. The performance criteria which should be met for a system to qualify, were fulfilled: a detection limit of ≤0.2 ng for all target compounds, replicate precision for a calibration standard and ambient samples within 20%. The stability of the target compounds during storage of sampled air in canisters was also evaluated at atmospheric pressure and relative humidity of 50%. Results show that, in the sampling conditions, compounds are not stable for more than a week. For validation experiments, samples were collected at the entrance of Tijuca National Park, located at the city of Rio de Janeiro. Isoprene was selected as a marker of biogenic emissions, and aromatic compounds were selected as markers of anthropogenic emissions, primarily vehicular emissions. Then, samples were collected in Saens Peña Square, a central area in the Tijuca District, in the northern part of the city, approximately 10 km from the entrance of Tijuca National Park. Volatile organic compounds were determined and the results were compared with previous data obtained in the same local using other methods.

Air samples were collected in the days before and during the 2014 FIFA World Cup at the major landmarks of Rio de Janeiro, Brazil. Samples were collected and analysed following Method TO-15 (US-EPA). Isoprene was selected as a marker of biogenic emissions, and benzene and toluene were selected as markers of anthropogenic emissions, primarily vehicular emissions. The isoprene, benzene, and toluene concentrations ranged from 0.39 to 2.32 µg m–3, 2.27 to 10.16 µg m–3, and 5.21 to 21.83 µg m–3, respectively. The kinetic and mechanistic reactivities of these compounds were also calculated to estimate the actual contribution of these compounds to atmospheric oxidant formation. The benzene and toluene concentrations indicated that greener areas of the city are strongly affected by urban emissions. Levels of isoprene were similar to those previously determined in other areas with vegetation.

The present work describes a more efficient methodology for the chlorination of water containing disperse dyes, where the chlorinated byproducts identified by mass spectra are compared. For this investigation, we tested the degradation of CI Disperse Blue 291 dye, 2-[(2-Bromo-4,6-dinitrophenyl)azo]-5-(diethylamino)-4-methoxyacetanilide) a commercial azo dye with mutagenic properties. The present work evaluates the photoelectrocatalytic efficiency of removing the CI Disperse Blue 291 dye from a wastewater of the textile industry. We employed NaCl as a supporting electrolyte. It should be noted that photoelectrocatalytic techniques are non-conventional method of generating chlorine radicals. The by-products formed in this process were analyzed using spectrophotometry, liquid chromatography, dissolved organic carbon, mass spectral analysis and mutagenicity assays. The process efficiency was compared with the conventional chlorination process adopted during sewage and effluents treatment processes. This conventional chlorination process is less efficient in removing color, total organic carbon than the photoelectrochemistry technique. Furthermore, we shall demonstrate that the mutagenicity of the generated by-products obtained using photoelectrocatalysis is completely different from that obtained by the conventional oxidation of chloride ions in the drinking water treatment process.

In this study, microcrystalline cellulose (MCC) was prepared from the acid hydrolysis of bacterial cellulose (BC) produced in culture medium of static Acetobacter xylinum. The MCC-BC produced an average particle size between 70 and 90 μm and a degree of polymerization (DP) of 250. The characterization of samples was performed by thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy (SEM). The MCC shows a lower thermal stability than the pristine cellulose, which was expected due to the decrease in the DP during the hydrolysis process. In addition, from X-ray diffractograms, we observed a change in the crystalline structure. The images of SEM for the BC and MCC show clear differences with modifications of BC fiber structure and production of particles with characteristics similar to commercial MCC.

The immobilization of gold nanoparticles (Au NPs) on silica is made possible by the functionalization of the silica surfaces with organosilanes. Au NPs could only be stabilized and firmly attached to silica-support surfaces that were previously modified with amino groups. Au NPs could not be stabilized on bare silica surfaces and most of the NPs were then found in the solution. The metal-support interactions before and after the Au NP formation, observed by X-ray absorption fine structure spectroscopy (XAFS), indicate a stronger interaction of gold(III) ions with amino-modified silica surfaces than with the silanol groups in bare silica. An amino-modified, silica-based, magnetic support was used to prepare an active Au NP catalyst for the chemoselective oxidation of alcohols, a reaction of great interest for the fine chemical industry.

We present the magnetic separation approach to facilitate the recovery of gold nanoparticle (AuNP) catalysts. The use of magnetically recoverable supports for the immobilization of AuNPs instead of traditional oxides, polymers or carbon based solids guarantees facile, clean, fast and efficient separation of the catalyst at the end of the reaction cycle. Magnetic separation can be considered an environmentally benign separation approach, since it minimizes the use of auxiliary substances and energy for achieving catalyst recovery. The catalyst preparation is based on the immobilization of Au3+ on the surface of core–shell silica-coated magnetite nanoparticles, followed by metal reduction using two different methods. AuNPs were prepared by thermal reduction in air and by hydrogen reduction at mild temperature. Interestingly, the mean particle size of the supported AuNPs was similar (ca. 5.9 nm), but the polydispersity of the samples is quite different. The catalytic activity of both catalysts in the aerobic oxidation of alcohols was investigated and a distinct selectivity for benzyl alcohol oxidation was observed.

Made available in DSpace on 2018-12-11T17:25:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-01. Added 1 bitstream(s) on 2021-07-15T15:03:47Z : No. of bitstreams: 1 S0103-50532015000901861.pdf: 835839 bytes, checksum: ff2a35b139836a0848c2a81a36398f7f (MD5) In this work, methylcellulose (MC) was produced from bacterial cellulose (BC), using dimethyl sulfate in a 3 h (MC3h) or 5 h (MC5h) reaction under heterogeneous conditions, with reagent substitution at each hour. MC3h showed a degree of substitution (DS) of 2.26 ± 0.13 and MC5h showed a DS of 2.33 ± 0.05. The two samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), differential thermal analysis (DTA), thermal gravimetric analysis (TGA), 13C nuclear magnetic ressonance (NMR) and 1H NMR techniques. The FTIR spectra of the BC and MC samples present significant differences in the regions from 3750 to 2750 cm-1 and from 1500 to 750 cm-1, which evidence the methylation of the samples. Solid state NMR spectroscopy of the MC samples was used to identify the 13C NMR signals of substitution at sites C-2, C-3 or C-6 in the glucopyranose units. The modification of bacterial cellulose produced a material with a high DS, determined by three different techniques (chemically and using the liquid 1H and solid 13C NMR spectra). These samples also demonstrate high crystallinity and thermal stability. With the MC samples synthesized in this work, transparent and resistant films were prepared and also a highly porous sponge like material. Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP) Instituto de Química, Universidade Federal de Uberlândia Faculdade de Ciências Integradas, Universidade Federal de Uberlândia Instituto de Química, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP)

The aim of this study was to determine the potential impact of a highly industrialized area on its urbanized surroundings. The area studied is home to a refinery, a thermoelectric plant and several petrochemical facilities industries. The concentrations of twelve elements were determined in PM10 and PM2.5 samples collected along a busy highway and near the petrochemical complex. Significantly higher concentrations of Ca, Mg, Mn, Fe, Cu and Al were observed in the petrochemical zone, but principal component analysis revealed similar patterns for both the highway site and a site approximately 1.5 km from the petrochemical complex, suggesting that the main pollution source in the area is vehicular flux. Higher concentrations in the industrial area may be attributed to intense diesel-powered truck and bus traffic movement, mainly due to the transport of supplies, fuel and gas. The observed concentrations of the elements Cr, Co, Ni, Cd and Pb were always lower than the detection limits of the technique used.

Methyl esters were prepared by the clean, one-step catalytic esterification of primary alcohols using molecular oxygen as a green oxidant and a newly developed SiO2-supported gold nanoparticle catalyst. The catalyst was highly active and selective in a broad range of pressure and temperature. At 3 atm O2 and 130 °C benzyl alcohol was converted to methyl benzoate with 100% conversion and 100% selectivity in 4 h of reaction. This catalytic process is much “greener” than the conventional reaction routes because it avoids the use of stoichiometric environmentally unfriendly oxidants, usually required for alcohol oxidation, and the use of strong acids or excess of reactants or constant removal of products required to shift the equilibrium to the desired esterification product.

The Petrochemical Complex of Duque de Caxias, Rio de Janeiro, is situated on a coastal strip between Guanabara Bay and a mountainous region covered with tropical forest. The complex comprises a refinery, a thermal power plant and several petrochemical industries. Higher rates of particulate–matter emissions are found in the region, mainly due to diesel emissions and the industrial activities of this area. In 2009 and 2010, samples were collected in three sites, and the 16 polycyclic aromatic hydrocarbons (PAHs) that are designated as priority pollutants by the US Environmental Protection Agency were determined. The sites are located in the vicinity of the Petrochemical Complex, one of them is on a roadside and the others are urban areas around the industrial complex. Multivariate analyses and diagnostic ratios show that the three studied areas were different, and the emissions seemed to be due to both gasoline and diesel vehicles. The carcinogenic PAHs represented the main fraction of the total PAHs determined in the particulate matter, and because the region is densely populated, these values may represent a health concern. The results indicate that regarding PAHs, the principal impact of the petrochemical complex is the high increase in the traffic of diesel vehicles and related tailpipe emissions.