This study has employed aggregate energy augmented production framework utilizing the gross domestic product (GDP), labor input, capital stock, energy, and export over the years from 1980 to 2014 on annual time series of the variables for Pakistan and South Asia panel. There is statistically insignificant association amid the variables for Pakistan while there is indication of long-run association amid the variables for panel of South Asia. The findings imply that energy conservation is efficient without hindering the economic growth and export expansion in Pakistan, albeit such kind of policy option is not much promising for the panel of four other South Asian countries. Furthermore, energy demand models must consider the role of exports expansion and its due impacts on the energy conservation of fossil fuels-based energy source and thereby on the trajectory of sustainable economic growth in the region.

Levels of amphetamine, methamphetamine, cocaine, and benzoylecgonine (BE), the metabolite of cocaine, were quantitated by solid phase extraction and liquid chromatography with tandem mass spectrometry (LC/MS/MS) in Forester Creek in San Diego County, CA, and in raw wastewater from the region’s sewage treatment plant. Drug residues in these surface waters were detected with 100% frequency. Mean concentrations were 0.022 ± 0.016, 0.450 ± 0.398, 0.024 ± 0.014, and 0.019 ± 0.012 μg/L for amphetamine, methamphetamine, BE, and cocaine respectively. Nonparametric testing by Spearman rank correlation showed significant (p < 0.05) positive correlations between the illicit drugs and traditional chemical markers (caffeine and sucralose) of sewage, with the exception of cocaine and sucralose. Because BE is a metabolite unique to human excretion, its presence in both wet and dry weather stream flows suggests a chronic and continuous condition of human sewage contamination in this urban southern California stream. Wastewater-based analysis also provided a direct way of measuring drug use within the population. Back-calculations of per-capita community drug consumption rates yielded values for amphetamine, methamphetamine and cocaine at 591, 5397, and 751 mg/d/1000 people, respectively. Notably, methamphetamine per-capita consumption rates determined in the present study for this southern California community were among the highest rates ever reported for the U.S. or Europe, and serve to confirm that methamphetamine use is surging in this area of southern California close to the USA-Mexico border.

A sensitive, specific, precise, accurate, and fast method Swas suitably developed for the determination of selected heavy metals including Cd, Cu, Fe, Pb, and Zn in tap water samples by inductivity coupled plasma-optical emission spectrometry (ICP-OES) after pre-concentration using Chelex-100 ion exchange resin. This method is based on studying several parameters including pH, weight of Chelex-100, HNO₃ concentration, flow rate, and column diameter. It was found that the suitable conditions used for pH, weight of Chelex-100, HNO₃ concentration, flow rate, and column diameter were 6, 4 g, 2 M, 1 mL/min, and 1 cm, respectively. Under these conditions, high recoveries were achieved with values of 95%, 106%, 77%, and 91% for Cu, Fe, Pb, and Zn, respectively. A total of 90 tap water samples were collected from five sampling zones of Irbid City, North Jordan, including (A: Barha zone; B: West and Zabda zone, C: South zone, D: East and city center zone, and E: North zone), and analyzed for Cd, Cu, Fe, Pb, and Zn; also the pH and electric conductivity (EC) values were measured. Moreover, the correlations between metals’ concentrations and type of tanks (iron, plastic, or semantic), type of pipes (iron or plastic), age of tanks, and age of pipes were evaluated. The mean concentrations of tested metals in tap water samples collected from zone A, zone B, zone C, zone D, and zone E, respectively, were the following: Cu (9.9 μg/L, 56.2 μg/L, 139.3 μg/L, 139.5 μg/L, and ND μg/L), Fe (463.6 μg/L, 237.8 μg/L, 55.4 μg/L, 142.5 μg/L, and 359.4 μg/L), Pb (60.6 μg/L, 25.6 μg/L, ND, 7.7 μg/L, and 40.3 μg/L), and Zn (189.4 μg/L, 275.8 μg/L, 265.6 μg/L, 307.1 μg/L, and 147.6 μg/L), whereas Cd levels in all zones were below the detection limit. In addition, results indicated that Pb and Fe had the same trend that is exceeding the permissible limit set by WHO, EPA, and Jordanian guidelines. A high positive correlation (r = 0.93) was found between Pb and Fe. Also, the altitude had a positive correlation between Pb and Fe concentrations, that is, as the altitude increases the concentration of Pb and Fe increases.

All processes in agro-industries consume water and generate large volumes of nutrient-rich effluents. To recycle effluents from a sugar–alcohol industry in the Northeastern Brazil (Coruripe, Alagoas), the effect of a daily application of a microbial formulation (containing five indigenous bacteria and two fungi), at the entrance of the two first facultative ponds (D, E) of its treatment plant formed by seven ponds (A–G), was evaluated in the sugarcane harvests of 2014/2015 and 2015/2016. Fortnightly, the values of 11 physicochemical parameters were checked and statistically compared (one and two-way ANOVA) in untreated (sedimentation pond A) and post-treated effluent (last facultative pond G), during both harvests. The treated effluent presented statistically significant improvements (p > 0.05), even between harvests, with averages of removal of organic matter of ca. 79.21% and 90.62%, and increases of the dissolved oxygen (DO) of ca. 72% and 74%, as well as the average increase of pH was ca. 42% and 50%. This better quality residue generally satisfied the class III level of the Brazilian Resolution 357/2005 (National Council for the Environment (CONAMA)), for water reuse in sugarcane irrigation on the yellow clay latosol soil, since it still is a light source of organic matter, nitrites and phosphorus, reducing the need of fertilizers for maintaining the productivity with low risk of salinization. According to Pearson’s bivariate correlation coefficient, while the DO and pH have positive correlation, they both have general inverse relation with the other physicochemical parameters evaluated and vice versa.

In less than two decades, the global tourism industry has overtaken the construction industry as one of the biggest polluters, accounting for up to 8% of global greenhouse gas emissions as reported by the United National World Trade Organization (UNWTO 2018). This position resonates the consensus of the United Nations Framework Convention on Climate Change (UNFCCC). Consequently, research into the causal link between emissions and the tourism industry has increased significantly focusing extensively on top earners from the industry. However, few studies have thoroughly assessed this relationship for small island economies that are highly dependent on tourism. Hence, this study assessed the causal relationship between CO₂ emissions, real GDP per capita (RGDP) and the tourism industry. The analysis is conducted for seven tourism-dependent countries for the period 1995 to 2014 using panel VAR approach, with support from fully modified ordinary least square and pooled mean group–autoregressive distributed lag models. Unit root tests confirm that all variables are stationary at first difference. Our VAR Granger causality/block exogeneity Wald test results show a unidirectional causality flowing from tourism to CO₂ emission, RGDP and energy consumption, but a bi-directional causality exists between tourism and urbanization. This implies that in countries that depend on tourism, the behaviour of CO₂ emission, RGDP and energy consumption can be predicted by the volume of tourist arrivals, but not the other way around. The impulse response analysis also shows that the responses of tourism to shocks in CO₂ appear negative within the 1st year, positive within the 2nd and 3rd years but revert to equilibrium in the fourth year. Finally, the reaction of tourism to shocks in energy consumption is similar to its reaction to shocks in RGDP. Tourism responds positively to shocks in urbanization throughout the periods. These outcomes were resonated by the Dumitrescu and Hurlin causality analysis where the growth-induced tourism hypothesis is validated as well as feedback causality observed between tourism and pollutant emission and urbanization and pollutant emission in the blocks over the sampled period. Consequently, this study draws pertinent energy and tourism policy implications for sustainable tourism on the panel over their growth trajectory without compromise for green environment.

In this work, hierarchical structure TiO₂/hemp stem biochar carbon (HSBC) and C₃N₄-TiO₂/HSBC were successfully fabricated, which were used as efficient visible-light photocatalyst degradation for ammonia nitrogen from aqueous solution. The as-prepared C₃N₄-TiO₂/HSBC hybrid catalyst showed the higher efficient photocatalytic activity for decomposition of ammonia nitrogen than those of pure TiO₂ and TiO₂/HSBC, suggesting suppressed recombination of photogenerated charges and promoted mass transfer due to synergistic effect, and thus increased photocatalytic degradation activity. The degradation of ammonia follows a pseudo-first-order kinetics. All prepared catalysts demonstrated extremely photocatalytic efficiency under visible-light and UV light illumination; the ammonia nitrogen photocatalytic degradation activity of C₃N₄-TiO₂/HSBC can reach 90.3% under UV light while the degradation activity achieved about 50.7% under visible-light irradiation. The results revealed that the h⁺ was dominantly active intermediates in the process of photocatalytic degradation. The prepared catalysts are promising for the degradation of ammonia nitrogen from water resource.

Strict environmental laws have been put in place around the world to reduce the amount of sulfur in the fuel to reduce the emissions of harmful gases from fuel combustion and improve air quality. Therefore, extensive researches have been undertaken to devise effective processes or to improve the desulfurization processes. Among the desulfurization processes, the oxidative desulfurization (ODS) process is a promising method to achieve very low and near-zero sulfur content of the fuel. In this process, sulfur compounds are converted to the corresponding sulfone by a catalyst and in the presence of an oxidant. The obtained compounds by polar solvents or adsorbents are removed from the fuel. In recent decades, extensive studies have been carried out on the catalysts used in the oxidative desulfurization process. In this review, a comprehensive survey has been performed on heterogeneous catalysts used in the oxidative desulfurization process. According to the reported researches, the heterogeneous catalysts used can be divided into five groups: ionic liquids, carbon materials, polyoxometalates, transition metal oxides stabilized on porous solid substrates, and metal–organic frameworks. The proposed mechanisms with different catalysts have also been studied in this work.

A quick, easy, cheap, effective, rugged, and safe pretreatment method using dispersive solid-phase extraction was developed to quantify kasugamycin in Chinese cabbage samples by using ultra-performance liquid chromatography/tandem mass spectrometry. A pretreatment method involving precolumn transformation was utilized to determine the residue of saisentong in Chinese cabbage through high-performance liquid chromatography/ultraviolet detection. These methods were successfully applied through field trials to determine the contents of kasugamycin and saisentong in Chinese cabbage. The dissipation of kasugamycin and saisentong in Chinese cabbage followed first-order kinetics with a linear correlation coefficient of 0.9066–0.9731 at the 95% confidence level. The half-lives of kasugamycin and saisentong in Chinese cabbage were 1.8–2.0 and 2.2–3.8 days, respectively. Terminal residual levels of kasugamycin in Chinese cabbage were not detected 14 days after application. The dietary risk assessment of kasugamycin and saisentong in Chinese cabbage showed that their risk quotients were 0.93 and 2.58%, respectively, in the preharvest interval (PHI) of 14 days. Kasugamycin and saisentong in Chinese cabbage did not pose potential health hazards at PHI of 14 days. The maximum residue limits of kasugamycin and saisentong in Chinese cabbage were 0.02 and 0.36 mg/kg, respectively, and 14 days was the safe PHI.

Trade openness is one of the main channels of globalization and technological transfers. In environmental economic literature, the implications of trade openness remain controversial and still could be potential drivers of carbon dioxide emissions. This study therefore explores the effect of trade openness in developed countries using EU-18 economies. We employed an econometric approach that accounts for cross-section dependence among study variables. The panel CIPS and CADF unit root show that the variables are stationary and the long-run relationship was confirmed in Westerlund cointegration tests. The mean group (MG) and augmented mean group (AMG) results show that trade openness increases CO₂-emissions in EU-18. Again, energy consumption and urbanization escalate emissions. The study confirmed the environmental Kuznets curve. Finally, pollution halo and pollution haven hypothesis were confirmed at both estimation methods. The Dumetriscu-Hurlin Granger causality test results confirmed bidirectional causality between trade openness and energy consumption and between trade openness and economic growth. Again, unidirectional Granger causality is running from trade openness and CO₂ emissions. Policy recommendations are further proposed.

Aerosol acidity (pH), one of key properties of fine-mode particulate (PM₂.₅), depends largely on nitrate and sulfate in particle. The mass contribution of nitrate relative to sulfate in PM₂.₅ has tended to increase in many regions globally, but how this change affects aerosol pH remains in debate. In this way, we measured PM₂.₅ ionic species and oxygen isotopic composition of nitrate in the eastern China, and predicted aerosol pH using the ISORROPIA-II model. When nitrate to sulfate molar ratio increases and thus PM₂.₅ is gradually enriched in ammonium nitrate (NH₄NO₃), aerosol pH tends to increase. The oxidation of nitrogen dioxide (NO₂) by hydroxyl radical is responsible for most of nitrate formation (generally above 60%). These indicate that nitrate formation through gas-to-particle conversion involving ammonia and nitric acid results in increasing aerosol pH with increasing molar ratio of nitrate to sulfate. Conversely, aerosol pH is expected to decrease with increasing relative abundance of nitrate as ammonia emissions are lowered. Our research concludes that it should be considered to reduce aerosol NH₄NO₃ by reducing the precursors of nitric oxide and ammonia emissions, to substantially improve the air quality (i.e., reduce PM₂.₅ levels and potential nitrate deposition) in China.