Environmental degradations are mainly caused by the use of different energy resources for economic growth. This research examined the influence of energy consumption (coal consumption, oil consumption, and gas consumption) and economic growth on environmental degradation in Pakistan. This research used newly developed method dynamic ARDL simulations to scrutinize the actual influence of positive and negative change in the use of coal consumption, oil consumption, and gas consumption for energy and economic growth on environmental degradation in Pakistan. The examined results of dynamic ARDL indicate that economic growth, coal consumption, oil consumption, and natural gas consumption have positive impact on the environmental degradations in Pakistan both in short run and long run. It is suggested that environmental degradations can be reduced by promoting renewable energy sources for energy.

Ozone (O₃) is an adverse environmental factor posing damage to ornamental plants. Thus, it is important to seek an effective way of enhancing plant tolerance to O₃-induced damage. Methyl jasmonate (MJ) and melatonin (MT) are plant growth regulators (PGRs) involved in plant abiotic stress responses. In this study, compared with the control group of plants without ozone, the influence of exogenous MJ (0, 10, 50, 100, and 150 μM) and MT (0, 0.1, 0.5, 2.5, and 12.5 μM) on the resistance of Malus crabapple ‘Hong Jiu’ was evaluated under O₃ stress (100 ± 10 nL/L for 3 h). Our data revealed that levels of MDA were significantly enhanced following O₃ treatment compared with plants without O₃. O₃ induced the activities of antioxidant enzymes and the accumulation of non-enzymatic antioxidants. While lower malondialdehyde (MDA) content, greater activities of antioxidant enzymes, and higher levels of soluble protein and non-enzymatic antioxidants were observed in PGRs-pretreated plants than in non-PGRs-pretreated plants under O₃ stress. Based on the above results and air pollution tolerance index (APTI), an exogenous supply of MJ and MT to Malus crabapple ‘Hong Jiu’ seedlings was protective for O₃-induced toxicity. The present study provides new insights into the mechanisms of MJ and MT amelioration of O₃-induced oxidative stress damages in Malus crabapple ‘Hong Jiu.’

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.

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.

The low-low temperature electrostatic precipitator (LLT-ESP), a combination of a traditional temperature electrostatic precipitator (ESP) and a non-leakage media gas-gas exchange (MGGH), could reduce the inlet flue gas temperature below the dew point and improved the performance of the ESP. Particulate matter (PM) from the stationary sources contains filterable particulate matter (FPM) and condensable particulate matter (CPM). In this study, coal with a high ash content (coal-HA) was burned, and the emission characteristics and removal efficiencies of the particulate matter in an LLT-ESP were investigated. The standards used to test filterable and condensable PM were ISO standard 23210-2009 and U.S. EPA Method 202, respectively. The LLT-ESP was efficient in removing filterable PM, with a total filterable PM removal efficiency as high as 99.6%. The removal efficiency of filterable PM increased with increasing particulate size and decreasing imported flue gas temperature. The LLT-ESP also provided excellent removal of condensable PM with a condensable PM removal efficiency exceeding 77%. Upstream of the LLT-ESP, the concentrations of filterable PM were much higher than those of condensable PM. Downstream of the LLT-ESP, the relationship between the quantities of condensable and filterable PM reversed. To reduce the emissions of PM from coal-fired power plants, more attention should be paid to controlling condensable PM. The temperature of the flue gas upstream of the LLT-ESP played an important role in eliminating condensable PM. At lower imported flue gas temperature operation conditions, the removal efficiency of the LLT-ESP for the condensable PM and the escaping mass concentration of condensable PM increased. Among the organic fraction of the condensable PM, hydrocarbons and esters were dominant. Meanwhile, SO₄²⁻ was the primary component, followed by Cl⁻ in anions. Na⁺, Ca²⁺, and Fe³⁺ were the main components in metal ions. Particles with diameters ≥ 10 μm, which contained most of the Si and Al, were dominant in the fly ash collected from sections 1 and 2 of the LLT-ESP. The main particles in sections 3 and 4 were PM₁₀, which contained the highest concentrations of Ca and Fe.

Modern farming practice features extensive overuse of additives in animal feed. Subsequent use of manure as a fertilizer has resulted in significant heavy metal accumulation in agricultural soil, which is particularly apparent in areas of intensive farming. Here, samples of dairy feed, manure, water, and soil were collected from four intensive dairy farms in China and analyzed to assess selected heavy metal concentrations (Cu, Zn, Cr, Ni, Pb, and Cd). Results revealed that all feed samples contained the selected heavy metals, attesting to the wide use of additives during intensive dairy farming. The average Cr and Pb concentrations were 6.1 to 17.1 times greater than their recommended guidelines. Overall, average heavy metal concentrations in manure decreased in the following order: Zn > Cu > Cr > Ni > Pb > Cd. Using data obtained from the sequential extraction procedure, proposed by the Community Bureau of Reference (BCR), metal bioavailability also decreased according to the following order: Pb (69.4%) > Cr (63.7%) > Ni (60.8%) > Cu (53.4%) > Zn (50.0%) > Cd (34.5%). Heavy metal levels in sampled wastewater were also relatively high; however, surface and well water levels were relatively low. Although use of manure in dairy farming has not resulted in serious pollution until now, Zn, Cu, and Cd are all known to pose significant risk to soil quality. Finally, principal component analysis (PCA) results indicated that heavy metal levels in soil originated predominantly from parent soil materials and were then enhanced by anthropogenic sources.

Climate change adversely affects food security all over the world, especially in developing countries where the increasing population is confronting food insecurity and malnutrition. Crop models can assist stakeholders for assessment of climate change in current and future agricultural production systems. The aim of this study was to use of system analysis approach through CSM-CERES-Millet model to quantify climate change and its impact on pearl millet under arid and semi-arid climatic conditions of Punjab, Pakistan. Calibration and evaluation of CERES-Millet were performed with the field observations for pearl millet hybrid 86M86. Mid-century (2040–2069) climate change scenarios for representative concentration pathway (RCP) 4.5 and RCP 8.5 were generated based on an ensemble of selected five general circulation models (GCMs). The model was calibrated with optimum treatment (15-cm plant spacing and 200 kg N ha⁻¹) using field observations on phenology, growth and grain yield. Thereafter, pearl millet cultivar was evaluated with remaining treatments of plant spacing and nitrogen during 2015 and 2016 in Faisalabad and Layyah. The CERES-Millet model was calibrated very well and predicted the grain yield with 1.14% error. Model valuation results showed that there was a close agreement between the observed and simulated values of grain yield with RMSE ranging from 172 to 193 kg ha⁻¹. The results of future climate scenarios revealed that there would be an increase in Tₘᵢₙ (2.8 °C and 2.9 °C, respectively, for the semi-arid and arid environment) and Tₘₐₓ (2.5 °C and 2.7 °C, respectively, for the semi-arid and arid environment) under RCP4.5. For RCP8.5, there would be an increase of 4 °C in Tₘᵢₙ for the semi-arid and arid environment and an increase of 3.7 °C and 3.9 °C in Tₘₐₓ, respectively, for the semi-arid and arid environment. The impacts of climate changes showed that pearl millet yield would be reduced by 7 to 10% under RCPs 4.5 and 8.5 in Faisalabad and 10 to 13% in Layyah under RCP 4.5 and 8.5 for mid-century. So, CSM-CERES-Millet is a useful tool in assessing the climate change impacts.

The overdosage use of pesticide was harmful to the environment and human health, which was mainly caused by the low utilization rate of the pesticide. However, the pesticide microcapsule with sustained-release and stimulating response properties could effectively solve this problem. Preparation of carboxymethyl cellulose grafting dimethyldiallylammonium chloride (CMC-g-PDMDAAC) through grafting polymerization and trapping as well as encapsulation of avermectin (AVM) via electrostatic interactions resulted in the formation of AVM/CMC-g-PDMDAAC microcapsules. The results showed that the particle size was 200~300 nm. The encapsulation efficiency was as high as 72.06%. Furthermore, the remaining rate of encapsulated AVM increased from 50.0 to 81.60% after UV irradiation for 359 min. The microcapsules exhibited significant enzyme and pH stimuli responsiveness. Finally, CMC-g-PDMDAAC had no significant difference effect on the toxicity of AVM, AVM could be found, and DMDAAC featured a synergistic effect on the toxicological effects of AVM. Graphical abstract

To improve crop yielding, a large amount of fungicides is continuously applied during the agricultural management, while the effects of fungicides residues on microbial processing of N in soil need further study. In the present study, two broad spectrum fungicides, chlorothalonil and carbendazim, were applied at the rates of 5, 10, and 50 mg of active ingredient (A.I.) per kg of dry soil combined with urea with 200 mg of N per kg of dry soil under laboratory conditions. The results showed that chlorothalonil obviously retarded the hydrolysis of urea, whereas carbendazim accelerated it in 4 days after the treatments (P < 0.05). Chlorothalonil reduced denitrification, nitrification, and N₂O production (P < 0.05), but not for carbendazim. Further analysis on N-associated microbial communities showed chlorothalonil reduced nitrosomonas populations at the rates of 10 and 50 mg of A.I. per kg and autotrophic nitrifying bacterial populations at three application rates (P < 0.05), but Carbendazim decreased nitrosomonas populations only at the rate of 50 mg of A.I. per kg and also autotrophic nitrifying bacterial populations at three rates and heterotrophic nitrifying bacterial populations at the rates of 10 and 50 mg of A.I. per kg. The reasons for this difference were ascribed to arrest urea hydrolysis and impediment of denitrification and nitrification processes by chlorothalonil. In conclusion, to improve crop yielding, chlorothalonil might be more beneficial to conserve soil N by improving soil N fertility, compared with carbendazim.