Ultrasound-assisted regeneration of powdered activated carbon (PAC) saturated with 4-chlorophenol (4-CP) was investigated in this work. The variables, i.e., acoustic frequency, density levels, regenerating solution species, spent PAC mass, and the number of repeated cycle, were optimized. The UV–Vis spectra, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), and pore structure analysis were used to characterize the regenerated PAC as compared to the virgin and spent PAC. The adsorption experiments indicated that the adsorption kinetics of 4-CP fitted well with the pseudo-second-order model, and the main chemisorption process was nonlinear and heterogeneous. The desorption results showed that the optimized regenerated conditions were identified as 40 kHz of frequency, 0.18 W/mL of sonication intensity, 0.1 M NaOH and 50% (v/v) ethyl alcohol mixture of regeneration solution, and 1 g/L of saturated PAC mass. Under this condition, the regeneration efficiency reached up to 86.81%. Hydroxylated oxidation products especially benzoquinone and hydroquinone were formed during ultrasound regeneration. Ultrasound mainly acted on surface functionalities, mesopores, and macropores of PAC through the hydroxyl radical oxidization resulted from the cavitation effect.

Vegetation is an important factor affecting nutrient enrichment ratio in runoff sediments but few studies have been examined in the effects of different vegetation scenarios on the monthly evolutions of particulate nitrogen (N) and phosphorus (P) loss. In this study, a vegetation correction coefficient was innovatively embedded in a dynamic particulate nutrient loss model to evaluate the monthly trends of particulate N and P loss in a small highly erodible watershed. Results indicate that (i) the monthly sediment yield from June to August 2013 accounted for the dominant percentage in this extreme hydrological year, which was consistent with the monthly trends of rainfall erosivity. The largest monthly sediment yield rate under four different vegetation scenarios all occurred in July with the values of 530.56, 258.09, 579.69, and 370.74 t km⁻². (ii) Particulate N and P loss from April to September changed significantly under different vegetation scenarios, and they were mainly concentrated in June and July 2013; only the N and P loss loads in July accounted for > 70% of annual load. However, the loads in January, February, March, October, November, and December were considered as zero because there was no erosive rainfall during the above 6 months. (iii) The reduction efficiency of particulate N and P loss by scenario 1 was about 1.7 times higher than scenario 3, which shows that forestland in sediment reduction was stronger than grassland and cropland in Zhifanggou Watershed. Results provide the underlying insights needed to guide vegetation reconstruction and soil conservation planning in loess hilly regions.

Sustainability of the environment has become pivotal in the modern world, and there have been enormous efforts by the world leaders and organizations to reduce the effects of hazardous production on the environment. This has led companies to implement pro-environment programs and work on sustainability to shift consumption from conventional products to green products. This study incorporates green trust, environmental concerns, and intrinsic religious orientation as a moderator into the theory of planned behavior. It aims to validate the theory of planned behavior and its extended form to predict Pakistani consumers’ eco-conscious behavior, and simultaneously assess the moderating effect of intrinsic religious orientation on consumers’ attitude towards green products. The data for the study was collected from 300 respondents through purposive sampling from Karachi, the metropolitan city of Pakistan. Structural equation model (SEM) was applied to test the proposed hypotheses. The results of SEM indicate that all paths in the model are significant, except the path from attitude towards green products to eco-conscious behavior. The results also indicate that intrinsic religious orientation has no moderating effect on the green trust and attitude towards green products. This study contributes to understand the effects of new constructs in the theory of planned behavior and their relationship with other variables in the model. It also provides theoretical and managerial implications to academics and marketing professionals for understanding and promoting eco-conscious consumer behavior.

The study emphasizes to examine the causal relationship among CO₂ emission, agricultural value added, industrial production, urbanization, nuclear energy consumption, and economic growth across the panel of 59 countries. The data is collected from World Bank database over the period of 1982–2015. For econometric estimations, we have divided the sample into different income groups: low income, lower middle income, upper middle income, and higher income. In case of higher income countries, empirical results have reported the unidirectional causality from agricultural value added to CO₂ emission, whereas, bidirectional causality between nuclear energy consumption and CO₂ emission. Upper-middle-income countries have confirmed the bidirectional causality between CO₂ emissions and agricultural added; however, unidirectional causality runs from nuclear consumption to CO₂ emission. According to Granger causality estimations, agricultural value added and nuclear energy consumption do not cause the CO₂ emission in low income and lower-middle-income countries. Long-run estimations have mentioned that higher agricultural value added leads to increase the CO2 emission, in upper middle income and higher income countries. On contrary, in case of low-income and lower-middle-income countries, agricultural value added has inverse relationship with CO₂ emission. Higher nuclear energy consumption tends to reduce the CO₂ emission, except the upper-middle-income countries.

This study was conducted to investigate the changes in leaf physiological parameters to abiotic stress induced by different levels of cement dust. On day 15, Arachis hypogaea L. plants (sowing day was considered as day 0) were divided into six groups, and cement was sprinkled over plants with the help of hand pump, twice a week at T₁ (5 g pot⁻¹), T₂ (8 g pot⁻¹), T₃ (10 g pot⁻¹), T₄ (15 g pot⁻¹), T₅ (20 g pot⁻¹), and T₀/control (0 g pot⁻¹), until fruit maturity. Morphometric parameters such as root and shoot length, leaf area, and seed weight were significantly higher in T₀, while the minimum was recorded in T₅. Physiological analyses of leaves and roots revealed a remarkable reduction (p < 0.05) in sugar, amino acid, and protein contents, while the concentration of enzymatic antioxidants was increased in cement-treated plants. The concentration of abscisic acid in leaves was significantly higher in treatment groups as compared with control, while gibberellic acid concentration was low. Strikingly, cement dust decreases the level of leaf photosynthetic pigments, reduces stomatal conductance, and adversely affects photosynthesis. Leaf histological analysis revealed confirmatory evidence of stomatal closure, cell damage, reduced cell area, and abridged leaf thickness. Salient features of the present study provide useful evidence to estimate cement dust as a critical abiotic stress factor, which has adverse effects on photosynthesis, leaf anatomical features, stomatal functioning, and productivity. Our work opens new avenues for a deep portfolio of cement-based stress mediating pathophysiology in Arachis hypogaea.

Grayanotoxin (GTX)-III is a Na-channel neurotoxin. Grayanotoxins can be found in the nectar, pollen, and other plant parts of the Rhododendron genus plants from the Ericaceae family. It is widely believed that honey produced from these plants, which are concentrated in the Black Sea region, is traditionally characterized as enhancing sexual performance. It is thought that the effective factor is dose for this compound, which has both beneficial and toxic effects reported. Therefore, it is aimed to evaluate the histological, immunohistochemical, and biochemical effects of acute and chronic impact of GTX-III in different doses on testes tissue in this study. For this purpose, 100 Sprague-Dawley male rats were divided into 5 separate groups for acute and chronic research. While dose groups were (control, 0.1, 0.2, 0.4, ve 0.8 μg/kg/bw) for experimental groups, a single dose (i.p.) was administered for acute impact whereas the same doses were administered daily for 3 weeks to assess chronic effect. At the end of the experiment, Johnsen testicular biopsy scoring was performed on testicular tissue samples, seminiferous tubule diameters were measured, and apoptotic cells were evaluated by TUNEL method. Testosterone, LH, and FSH levels were measured by ELISA method in serum and tissue specimens. It was found that Johnsen score of acute doses was significantly lower than the control group, and the diameter of the seminiferous tubules decreased significantly in acute and chronic dose-administered groups compared to the control. Hemorrhage, epithelial shedding, irregularity in seminiferous epithelium, and vacuolization were observed in acute and chronic dose-administered groups, and increase in apoptotic cells was determined. Hormone levels varied depending on the dose. In conclusion, it was found that dose-dependent acute and chronic effects of GTX-III are different, and this factor should be taken into account in studies to be carried out due to the adverse effects of high doses.

With the rapid economic development in the past decades, industrialization and urbanization in China has also rapidly developed and will continue in the next decades. However, the regional water shortage has posed great challenges for the sustainable development of big cities especially in north China. Here, we used the water ecological footprint model combined with the system dynamic model to assess the water resource carrying capacity and its sustainability in Zhangjiakou City, a typical water shortage city in north China. The calculated results showed that irrigation was the largest water consumer in Zhangjiakou. There existed a clear gap between water supply and water consumption in this city and such a gap is demonstrated by the high water resource pressure index. Our predicted results based on the water resource ecological footprint and the system dynamic model showed that although the improving water use efficiency has relieved the regional water shortage pressure, the efficiency gained would be to a large degree offset by increased water demands due to the increasing economic development. The annual average water shortage in Zhangjiakou in 2007–2050 would be up to 8.53 × 10⁸ m³, nearly half of the total local average annual water resource. To deal with the severe water shortage over the next three decades, great attention should be paid to scientific water resource managements and water pollution control. This research provides a long-term view of water resource pressure and provides recommendations for a sustainable water use under the rapid regional socioeconomic development.

Removal of the heavy metal ions in aqueous solution is an important technology for waste water treatment. The effects of using ultrasonic and microwave on synthesizing Pb²⁺, Zn²⁺, and Cu²⁺ imprinted mesoporous adsorbents (Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM) and their dynamic adsorption properties were studied. The microstructure and composition of the ion-imprinted mesoporous adsorbents were discussed in detail by TEM, FTIR, N₂ adsorption-desorption, XRD, and EDS. The pore sizes of mesoporous absorbents were improved more uniformly by using ultrasonic agitation than magnetic stirring. The elution efficiency of imprinting ions can be enhanced by microwave elution. Prepared Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM were used for dynamic adsorption study of heavy metals. The detected optimal feed rate was 20.0 mL/min and the influent concentration was 60 mg/L; the equilibrium adsorption capacities of Pb-IMA-UM, Cu-IMA-UM, and Zn-IMA-UM could reach 198 mg/g, 51.5 mg/g, and 57.3 mg/g, respectively. The dynamic regeneration performance of the adsorbent was also investigated with the Cu-IMA-UM sample. The adsorption rate remained above 89% after five dynamic regeneration experiments. At last, the actual wastewater from an electroplating industry was used as the research object. Three groups of dynamic adsorption coefficient contours of Pb-IMA-UM, Zn-IMA-UM, and Cu-IMA-UM were obtained when influents flowed into three adsorption columns separately. The experimental results showed that an ion-imprinted adsorbent had a much better adsorption capacity of imprinted ions under the various metals mixed conditions.

This work demonstrated a simple, low-cost, rapid, and effective biochemical oxygen demand (BOD) estimation system based on a packed-bed bioreactor that can be easily self-built on-site at a particular wastewater treatment plant for continuous monitoring of the influent and effluent. The use of natural microbial consortium that were collected from the target wastewater and immobilized on a cheap porous carrier simply by adhesion resulted in an acceptable accuracy of over 95%. The newly developed semi-continuous operating mode with peak-type signals was shown to be able to continuously estimate BOD at a high flow rate to overcome the flow dependence of the oxygen electrode, limit clogging issues, enhance the response time, and lower the limit of detection. The resulting packed-bed bioreactors could work continuously for 22 h with a coefficient of variance (CoV) of only 1.8% or for 13 h a day for several days with a maximum CoV of 1.4% and their response was observed to be stable over 80 consecutive measurements. They exhibited stable responses at a wide pH range of 6.5–8.5, which is also the recommended range for aerobic wastewater treatment, emphasizing the greater ease of use of natural microorganisms for BOD estimation.

The peri-urban soil is exposed to pollutants because of its proximity to the city, which may influence the quality of agricultural products. In this study, the occurrence of 16 trace elements (TEs), 16 polycyclic aromatic hydrocarbons (PAHs), and 33 contaminants of emerging concern (CECs) was analyzed in two soil sites of the peri-urban area of Barcelona (Spain) (S2 and S3) and a pristine site (S1). Levels of Pb (S2 164 and S3 150 mg kg⁻¹) are around 2.5 times higher than the guideline values. Values for Cu (178 mg kg⁻¹) in S2 are 1.8-fold higher, whereas for Zn, levels are slightly above the threshold in S2 (208 mg kg⁻¹) and S3 (217 mg kg⁻¹). The total concentrations of PAHs are significantly below the limits: 24 ng g⁻¹ dw (S1), 38 ng g⁻¹ dw (S2), 49 ng g⁻¹ dw (S3), whereas only some CECs are detected with low concentrations. We also developed a simple and rapid method to assess soil pollution. Here, we use two plant growth indexes (seed germination rate and root elongation at the initial stage) of three seeds (lettuce, tomato, and cauliflower) to assess soil chemical contamination on agriculture. In the peri-urban soil, the concentration of Pb was 2.5 times higher than the guideline values, whereas for Cu and Zn, values were slightly above their limits, while only few PAHs and CECs were detected. Results for principal component analysis suggest that root elongation is a more sensitive measurement endpoint than germination rate, especially for lettuce. The germination rate of tomato relied on the nitrate in the soil and decreased sharply in the site with pollution of Cu and As. Under the specific conditions of this study, cauliflower should not be recommended to assess environmental pollution due to its low sensitivity to pollutants. In conclusion, this is a low-cost, simple, and rapid method for evaluating the effects of chemical pollution of agriculture soils on seed growth.