Groundwaters are normally consumed without previous treatment and therefore the monitoring of contaminants in order to guarantee its safety is necessary. Thus, we aimed to evaluate the groundwater contamination by metals and emerging contaminants, seeking to understand the relationship between their presence in the groundwater and the use and land cover profile of Itaporã and Caarapó. In addition, the contaminant concentrations observed were compared with maximum permitted values (MPV) and/or with calculated water quality criteria (WQC) for human consumption to investigate possible human health risks due to the groundwater intake. We collected one groundwater sample from each of the 12 wells located in Itaporã and 11 wells located in Caarapó. The metals were analyzed using ICP-OES and the emerging contaminants using LC-MS/MS. At least 1 of the 9 metals analyzed was found in each of the samples. In 12 samples, the metal concentrations verified exceeded the MPV or calculated WQC. A risk to human health has been observed for metals Co, Mn, Cr, and Ni. The emerging contaminant concentrations found in some samples were low (ng/L) and probably did not pose health risks, but their presence in the groundwater showed the impact of agriculture and the inadequate disposal of domestic sewage in the wells of both cities.

Developing of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and 2D molecular descriptor calculations. Based on the intensities of two characteristic MS peaks, namely, [M] and [M-35], two classification criterions were proposed. According to criterion I, class 1 comprises [M] signals with the intensity higher than 800 NIST units, while class 2 consists of signals with the intensity lower or equal than 800. According to criterion II, class 1 consists of [M-35] signals with the intensity higher than 100, while signals with the intensity lower or equal than 100 belong to class 2. As a result of ANNs learning stage, five models for both classification criterions were generated. The external model validation showed that all ANNs are characterized by high predicting power; however, criterion I-based ANNs are much more accurate and therefore are more suitable for analytical purposes. In order to obtain another confirmation, selected ANNs were tested against additional dataset comprising popular sunscreen agents disinfection by-products reported in previous works.

Mosses can be used as biomonitors to monitor radionuclide deposition and heavy metal pollution in cities, forests, and grasslands. The aims of this work were to determine the activity concentrations of natural (²¹⁰Po, ²¹⁰Pb or ²¹⁰Pbₑₓ (excess ²¹⁰Pb is defined as the activity of ²¹⁰Pb minus the activity of ²²⁶Ra), ⁷Be, ⁴⁰K, ²²⁶Ra, ²³⁸U, and ²³²Th) and anthropogenic radionuclides (¹³⁷Cs) in moss body profiles and in situ underlying soils of moss samples and to assess/determine the distribution features and accumulation of these radionuclides. Activity concentrations of radionuclides in the samples were measured using a low-background gamma spectrometer and a low-background alpha spectrometer. Consistent with their source, the studied radionuclides in the moss samples and underlying soils were divided according to the principal component analysis (PCA) results into an airborne group (²¹⁰Po, ²¹⁰Pb (²¹⁰Pbₑₓ), ⁷Be, and ¹³⁷Cs) and a terrestrial group (⁴⁰K, ²³⁸U, ²²⁶Ra, and ²³²Th). The activity concentrations of ²¹⁰Po and ²¹⁰Pbₑₓ in moss body profiles were mainly concentrated in the stems–rhizoid parts, in which we measured some of the highest ²¹⁰Po and ²¹⁰Pbₑₓ levels compared to the results in the literature. ⁷Be mainly accumulated in the leaves–stem parts. Different positive correlations were observed between ²¹⁰Po and ²¹⁰Pb and between ⁷Be and ²¹⁰Pb, which indicated that the uptake mechanisms of ²¹⁰Po, ²¹⁰Pb, and ⁷Be by moss plants were different, to some extent. ¹³⁷Cs was detected only in some moss samples, and the fraction of ¹³⁷Cs in the underlying soils was much lower than that in the moss, suggesting that mosses were protecting the underlying soils from further pollution. Except for ⁴⁰K, the terrestrial radionuclide (²³⁸U, ²²⁶Ra, and ²³²Th) content in mosses was predominantly at low levels, which indicated not only the inability of mosses to use those elements for metabolic purposes but also the rather poor capability of mosses to directly mobilize, absorb, and transport elements (U, Ra, or Th) not dissolved in water.

Secondary aluminum smelting industry, as an important source of polychlorinated naphthalene (PCN) in environment, has been concerned in recent years. To figure out the emission characteristics of PCNs and the potential influence on surrounding environment, two typical secondary aluminum smelting plants were selected and PCNs were determined in flue gas, fly ash, aluminum slag, soil, and air samples collected at and around the plants by GC-MS coupled with DFS. PCN emission factors from the flue gas of the two plants (mean 0.006 ng toxic equivalents/t) were found obviously decreased compared with similar smelting process detected in 2010. The stage of feeding material was still the major PCNs discharge period during the whole smelting process. The total PCN concentrations in air were found to be ranked as following: workshops (290–1917 pg/m³), the area near the workshops (62.3–697 pg/m³), and the surrounding areas (29.9–164 pg/m³, mean 64.5 pg/m³). Similar high concentrations of PCNs were found in soil from by the workshop door (983 ng/g dry weight). Soil-air exchange calculations indicated that mono-CN to tetra-CN would volatilize but hepta-CN and octa-CN would be deposited to the soil. Exposure of plant workers and local inhabitants to PCNs through inhalation was found to be acceptable but higher (especially for workers in the workshops) than living areas. The workshop and the nearby area are potential PCNs polluted areas and should be paid attention during the practical operation.

To optimize the simultaneous removal of NOₓ and Hg⁰, a series of CuₐCebZrcO₃/γ-Al₂O₃ catalysts prepared by the impregnation method were explored and their physical and chemical properties were analyzed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), NH₃-temperature-programmed desorption (NH₃-TPD), H₂-temperature-programmed reduction (H₂-TPR), in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFT), and Fourier transform infrared spectroscopy (FT-IR). The results showed that 15% Cu₁.₄Ce₀.₅₅Zr₀.₂₅O₃/γ-Al₂O₃ resulted in the highest conversion efficiency for the simultaneous removal of NOₓ (93%) and Hg⁰ (85%) at low temperatures (200 to 300 °C). Meanwhile, 15% Cu₁.₄Ce₀.₅₅Zr₀.₂₅O₃/γ-Al₂O₃ showed good stability and resistance to SO₂ and H₂O, which is due to its low crystallinity, good textural performance, and strong redox ability. According to the TPD, TPR, and XPS results, the strong acidic character of 15% Cu₁.₄Ce₀.₅₅Zr₀.₂₅O₃/γ-Al₂O₃ promoted the removal of NOₓ and Hg⁰. The synergistic effect between CuO and CeO₂ in 15% Cu₁.₄Ce₀.₅₅Zr₀.₂₅O₃/γ-Al₂O₃ can increase the mobility of chemically adsorbed oxygen and activates lattice oxygen, leading to an excellent performance. The DRIFT results showed that NH₃, NH₄⁺, nitrate, and nitrite participated in the selective catalytic reduction (SCR) reaction. On the basis of our experimental results, Hg⁰ and NOₓ removal mechanisms were proposed as Hg (ad) + O* → HgO (ad) and 2NH₃/NH₄⁺ (ad) + NO₂/NO₃⁻ (ad) + NO→2N₂ + 3H₂O/2H⁺, respectively.

This study explores the climate impacts of on-road tourist transportation with alternate mitigation strategies. To this end, greenhouse gas (GHG) emissions for 2016 and emissions under four “what-if” scenarios were estimated for a popular tourist site in Pakistan, i.e., Murree Hills, using the international vehicle emissions model. Alternate scenarios included occupancy optimization, bus transit system, and Euro II and Euro IV implementation. The emissions were further decomposed using the log mean Divisia index method to study the drivers of global warming potential (GWP) mitigation. As per the results, the total 20-year GWP for 2016 was equal to 51,262 tons CO₂ equivalent, and maximum reduction was achieved under the bus transit system scenario having a 20-year GWP of 25,736 tons CO₂ equivalent, i.e., 49.8% reduction. Relative to the base year, GWP reductions were also quite significant for Euro IV (46.8%), Euro II (45.8%), and occupancy optimization (32.3%) scenarios. For the base year, CO₂ held a share of 87.3% in total emissions; however, its share in the 20-year GWP was 39.7% indicating its reduced impact on total GWP as compared to N₂O, CO, NOx, VOC, and CH₄. Based on the decomposition results for alternate scenarios, GWP mitigation was mainly driven by CO, CH₄, NOx, VOCs, and partially by CO₂, while N₂O negatively affected GWP mitigation. These results provide several policy-level instruments for developing countries to design a transition to an eco-friendly tourist transport management system. The policy implications from this study can be used to promote an eco-tourism industry.

This study explores the zero-valent iron (ZVI) dechlorination of pentachlorophenol (PCP) and its dependence on the dissolved oxygen (O₂), presence/formation of iron oxides, and presence of nickel metal on the ZVI surface. Compared to the anoxic system, PCP dechlorination was slower in the presence of O₂, which is a potential competitive electron acceptor. Despite O₂ presence, Ni⁰ deposited on the ZVI surfaces catalyzed the hydrogenation reactions and enhanced the PCP dechlorination by Ni-coated ZVI bimetal (Nic/Fe). The presence of O₂ led to the formation of passivating oxides (maghemite, hematite, lepidocrocite, ferrihydrite) on the ZVI and Nic/Fe bimetallic surfaces. These passive oxides resulted in greater PCP incorporation (sorption, co-precipitation, and/or physical entrapment with the oxides) and decreased PCP dechlorination in the oxic systems compared to the anoxic systems. As received ZVI comprised of a wustite film, and in the presence of O₂, only ≈ 17% PCP dechlorination observed after 25 days of exposure with tetrachlorophenol being detected as the end product. Wustite remained as the predominant oxide on as received ZVI during the 25 days of reaction with PCP under oxic and anoxic conditions. ZVI acid-pretreatment resulted in the replacement of wustite with magnetite and enhanced PCP degradation (e.g. ≈ 52% of the initial PCP dechlorinated after 25 days under oxic condition) with accumulation of mixtures of tetra-, tri-, and dichlorophenols. When the acid-washed ZVI was rinsed in NiSO₄/H₂SO₄ solution, Ni⁰ deposited on the ZVI surface and all the wustite were replaced with magnetite. After 25 days of exposure to the Nic/Fe, ≈ 78% and 97% PCP dechlorination occurred under oxic and anoxic conditions, respectively, producing predominantly phenol. Wustite and magnetite are respectively electrically insulating and conducting oxides and influenced the dechlorination and H₂ production. In conclusion, this study clearly demonstrates that the dissolved oxygen present in the aqueous solution decreases the PCP dechlorination and increases the PCP incorporation when using ZVI and Nic/Fe bimetallic systems. The findings provide novel insights towards deciphering and optimizing the performance of complex ZVI and bimetallic systems for PCP dechlorination in the presence of O₂.

A magnesia–pullulan (MgOP) composite has been developed to remove phosphate from a synthetic solution. In the present study, the removal of phosphate by MgOP was evaluated in both a batch and dynamic system. The batch experiments investigated the initial pH effect on the phosphate removal efficiency from pH 3 to 12 and the effect of co-existing anions. In addition, the adsorption isotherms, thermodynamics, and kinetics were also investigated. The results from the batch experiments indicate that MgOP has encouraging performance for the adsorption of phosphate, while the initial pH value (3–12) had a negligible influence on the phosphate removal efficiency. Analysis of the adsorption thermodynamics demonstrated that the phosphate removal process was endothermic and spontaneous. Investigations into the dynamics of the phosphate removal process were carried out using a fixed bed of MgOP, and the resulting breakthrough curves were used to describe the column phosphate adsorption process at various bed masses, volumetric flow rates, influent phosphate concentrations, reaction temperatures, and inlet pH values. The results suggest that the adsorption of phosphate on MgOP was improved using an increased bed mass, while the reaction temperature did not significantly affect the performance of the MgOP bed during the phosphate removal process. Furthermore, higher influent phosphate concentrations were beneficial towards increasing the column adsorption capacity for phosphate. Several mathematic models, including the Adams–Bohart, Wolboska, Yoon–Nelson, and Thomas models, were employed to fit the fixed-bed data. In addition, the effluent concentration of magnesium ions was measured and the regeneration of MgOP investigated.

Annually, over 5.5 trillion cigarettes are produced worldwide, and it is estimated that 4.5 trillion cigarette butts (CBs) are still being littered in the world. The dispersal of the CBs has caused this hazardous waste to be considered as one of the most important litters and environmental risks all over the world. This systematic study with the search protocol definition and keyword identification was developed to find the CBs control and recycling methods by searching in five scientific databases. Founded articles were monitored and finally, 35 related articles were selected and studied by the authors. The results of this study showed that CBs recycling methods have been tested in 10 specific categories all over the world. The CBs have been applied without any pre-processing methods in the bricks and asphalt production. However, other applications of the CBs such as the absorbent material production, vector control, and use as a biofilm carrier in wastewater treatment need various processing methods. The researchers also presented models and suggestions such as taxes, penalties, and public education for the control of CBs littering. Despite the innovative methods applied for the CBs recycling in previous studies, CBs have not received much attention in terms of pollutant control and environmental issues in recycling processes.

Road traffic accidents (RTAs) are among the life-threatening issues facing rural as well as sub-/urban communities. Several factors contribute to RTAs ranging from human to technical and natural/environmental impacts. Anthropogenic air pollution and corresponding environmental factors also increase the probability of RTAs. Current study reports the relationship of the weather conditions to RTAs. The study establishes the relevancy of different weather conditions like rainfall, temperature, fog, and wind storm with the incidences of RTAs in rural and urban settings of Vehari, Punjab—Pakistan. The results of the study showed that rainfall, severe coldness, fog, and heat conditions were directly related with the occurrence of RTAs. The percentage of RTAs which occurred due to fog, rainfall, temperature, and other weather-related factors was 34, 25, 21, and 20%, respectively. The age of the driver significantly correlated (R² = 0.60) with RTAs; the drivers in the age group 40–60 years caused the least RTAs during their drive. Since the smaller vehicles were involved in maximum RTAs, it relates negatively (R² = 0.82) to vehicles power. Among different vehicles motor bikes were involved in most (42%) of the reported RTAs. Therefore, during severe weather conditions, vehicles with smaller size and young drivers must be dealt with carefully while interacting (crossing, overtaking, and maneuvering) on the roads regardless of rural or urban conditions. Factors including civic sense, traffic education, vehicle size, drivers’ maturity, road conditions, and environmental impacts may be considered while designing traffic rules and traffic aware campaigns specific for developing countries such as Pakistan.