Waste biomass can be recycled to prepare biochar for soil restoration, in which process soil fertility would not be lost. In this work, biochar was prepared from waste pomelo peel, combined with ZnO, to be used to immobilize Cu(II) in contaminated soil, whose maximum adsorption capacity was up to 216.37 mg g⁻¹. Due to combination of ZnO, the BET surface area of biochar increased from 2.39 to 18.53 m² g⁻¹. Meanwhile, the surface functional groups increased, which was conducive to fixation of metal ion on the surface of biochar. Both pseudo-second-order kinetics and Langmuir isotherm model fit the experimental data well. Adsorption was easy to happen since the adsorption site on the surface of biochar/ZnO had a strong affinity with Cu(II). In addition, mechanism investigation indicated that Cu(II) was bond with biochar/ZnO mainly by non-bioavailable state (75.6%) primarily. It inferred that biochar/ZnO was an efficient and promising passivator in reducing heavy metal risk in soil.

Environmental concern related to Ag⁺ release from conventional AgNPs is expected to be prevented once contained into a magnetic core like magnetite or CoFe₂O₄. Accordingly, we obtained CoFe₂O₄ NPs by microwave-assisted synthesis, which AgNO₃ addition rendered Ag@CoFe₂O₄ NPs. NPs were characterized, and before exploring potential applications, we carried out 7-day wheat toxicity assays. Seed germination and seedling growth were used as toxicity endpoints and photosynthetic pigments and antioxidant enzymes as oxidative stress biomarkers. Total Fe, Co, and Ag determination was initial indicative of Ag@CoFe₂O₄ NPs uptake by plants. Then NPs localization in seedling tissues was sought by scanning electron microscopy (SEM) and darkfield hyperspectral imaging (DF-HSI). Not any silver ion (Ag⁺) was detected into the ferrite structure, but results only confirmed the presence of metallic silver (Ag⁰) adsorbed on the CoFe₂O₄ NPs surface. Agglomerates of Ag@CoFe₂O₄ NPs (~10 nm) were fivefold smaller than CoFe₂O₄ NPs, and ferrimagnetic properties of the CoFe₂O₄ NPs were conserved after the formation of the Ag@CoFe₂O₄ composite NPs. Seed germination was not affected by NPs, but root and shoot lengths of seedlings diminished 50% at 54.89 mg/kg and 168.18 mg/kg NPs, respectively. Nonetheless, hormesis was observed in roots of plants exposed to lower Ag@CoFe₂O₄ NPs treatments. Photosynthetic pigments and the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX) indicated oxidative damage by reactive oxygen species (ROS) generation. SEM suggested NPs presence in shoots and roots, whereas DF-HSI confirmed some Ag@CoFe₂O₄ NPs contained in shoots of wheat plants.

Freezing-thawing and saline-alkaline are the major abiotic stress for the pasture in most high-latitude areas, which are serious threats to the yield of pasture. In this study, the osmotic adjustment substances, membrane lipid peroxidation, and antioxidant enzymes activities of rye (Secale cereale L., cv. Dongmu-70) seedlings under different treatments: CK (no treatment), SC (Na₂CO₃ treatment), FT (freezing-thawing treatment), and FT+SC (combined Na₂CO₃ and freezing-thawing treatments), were investigated. At the freezing stage, the content of MDA and proline, the activity of APX, SOD, and POD increased with the decrease of the temperature in the leaves of rye seedlings in FT and FT+SC treatments and reached the maximum value at − 5 °C. In addition, the content of protein and H₂O₂, CAT activity reached the maximum value at 0 °C; the damage is larger under low temperature stress at 0 °C and − 5 °C in rye seedling. At the thawing stage, the content of MDA and H₂O₂ in seedling leaves decreased in FT and FT + SC treatments. These results demonstrated that proline content and antioxidant enzymes activities could play an important role in protecting cytomembrane and scavenging ROS respectively in rye under alkaline salt stress and freezing-thawing stress. The result also indicated rye seedlings were subjected to a freezing-thawing stress which resulted in a reversible (recoverable) injury.

Iron mining residue was evaluated as a potential catalyst for heterogeneous Fenton/photo-Fenton degradation of sulfonamide antibiotics. The residue contained 25% Fe₂O₃ and 8% CeO₂, as determined by X-ray fluorescence spectroscopy, as well as other minor phases such as P₂O₅, SiO₂, and TiO₂. X-ray photoelectron spectroscopy analysis revealed a lower content of iron oxides on the surface, which restricted interaction of the residue with H₂O₂. Despite this limitation and the relatively low specific surface area (26 m² g⁻¹) of the crude iron mining residue (without any pretreatment), the material presented high catalytic activity for Fenton degradation of sulfonamide antibiotics. The degradation was strongly dependent on the initial pH, showing the highest efficiency at pH 2.5. For this condition, a concentration of sulfathiazole below the detection limit was obtained within 30 min, under black light irradiation and using 0.3 g L⁻¹ residue, with low H₂O₂ consumption (0.2 mmol L⁻¹). The residue also provided highly efficient sulfathiazole degradation in the dark, with the concentration of the antibiotic decreasing to an undetectable level after 45 min. Simultaneous degradation of two sulfonamide antibiotics revealed higher recalcitrance of sulfamethazine, compared to sulfathiazole, but the levels of both antibiotics decreased to below the detection limit after 45 min. The residue was very stable, since no significant concentration of soluble iron was detected after the degradation process. Furthermore, high catalytic activity was maintained during up to five cycles, showing the potential of this material for use as a low-cost and environmentally compliant catalyst in Fenton processes.

This is the first nationwide survey of bisphenol A (BPA), methylparaben, ethylparaben, propylparaben, butylparaben, and o-phenylphenol, in Egypt’s water. Five hundred fifty-five water samples were collected from source water (SW, 109 samples) and drinking water (DW, 446 samples) of twenty-three Egyptian governorates. These chemicals were determined by direct ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) analysis of a filtered aliquot of samples. The impacts of the measured concentrations on the aquatic organisms and human health were evaluated as well. BPA, methylparaben, propylparaben, and butylparaben were frequently detected in SW and DW, while ethylparaben and o-phenylphenol were not detected whatsoever. The most frequently detected endocrine-disrupting chemical (EDC) was BPA in SW and methylparaben in DW. The recorded highest concentrations of BPA and methylparaben in SW and BPA and methylparaben, propylparaben, and butylparaben in DW were the highest worldwide. Of the investigated twenty-three governorates, the SW and DW of Aswan, Red Sea, Cairo, Sharqia, and Damietta were free of the studied EDCs. Contrarily, BPA, MeP, PrP, and BuP were detected in Sohag’s SW and DW. A detection ratio > 70% was recorded in SW of Faiyum, Dakahlia, and Ismailia, and > 90% in DW of Sohag, Port Said, Dakahlia, and Faiyum. The environmental risk assessment results excluded any human health risk even in the worst-case scenario and showed that BPA represents the highest risk to the aquatic organisms.

The percentage of agricultural land cover effect on water quality in Culiacan River basin is studied in this research. The basin contains only intensive cropland as primary economic activity with 60% of the total area. Mathematical relationships between percentages of cropland and total phosphorus (TP) and total nitrogen (TN) concentrations were established. Sampling sites in middle and lower basin and water quality information during 2013–2018 were considered, and percentages of cropland were obtained by geospatial methods including variable area buffers. During rainy season, coefficients of determination were less than 0.2, although quantified nutrient concentration was higher, related to point sources of pollution in the basin. During dry season, coefficients of determination were higher than 0.76 and 0.90 for TN and TP, respectively, with an exponential mathematical trend. Results suggest that intensive agriculture practices generate accelerated loss of soil consolidation, which is transported to water bodies. These soils are in continuous contact with fertilizers and pesticides, mostly organophosphates which have been transported by runoff and underground flows. Using the information generated will help to establish environmental management plans, and to improve environmental diagnosis and effect in countries where there is not enough historical cartographic information and/or water quality data.

Tramadol abuse is an increasingly alarming phenomenon among Egyptian Community especially among workers and drivers. Study profile and factors affecting tramadol abuse among industrial workers in Mid-Nile Delta Region. A cross sectional study among minibus drivers, construction and textile industries workers. From each target group 300 males were chosen randomly. The total sample size was 900 persons. Interview questionnaire was used for data collection. Diagnosis of tramadol abuse was according DSM-5 Criteria. Intake of tramadol was high among construction workers (92.3%) followed by bus drivers (53.0%) and lastly textile workers (25.3%). The main source of tramadol was friends (45.4%) followed by drug dealers (16.6%). The main reason of abuse was to improve mood (54.3%) followed by relief of pain and help to continue work (37.3%). Tramadol is prevalent among industrial workers due to different reasons related to the work load and stressful events. Ever intake of tramadol was high among construction workers followed by bus drivers and lastly textile workers. Drug testing for workers in workplace is a must to ensure community safety.

In this study, we develop a parallel heuristic search strategy based on a Bayesian approach for simultaneously recognizing groundwater contaminant sources and aquifer parameters (unknown variables) at sites contaminated with dense non-aqueous phase liquids (DNAPLs). The parallel search strategy is time-consuming because thousands of simulation models must run in order to calculate the likelihood. Various stand-alone surrogate systems for the simulation models have been established, but they also have unavoidable limitations. Thus, we develop an optimal combined surrogate system by combining Gaussian process, kernel extreme learning machine, and support vector regression methods using a differential evolution algorithm with a variable mutation rate based on the rand-to-best/1/bin strategy, thereby improving the approximation accuracy of the surrogate system to the simulation model and significantly decreasing the high computational cost. Utilizing the optimal combined surrogate system reduced the CPU time by more than 400 times. In the iterative parallel heuristic search process, each round of iteration involves determining the candidate points and state transitions. The Monte Carlo approach is used widely for selecting candidate point, but this approach does not readily converge to the posterior distribution for unknown variables when the probability density function types are complex with weak search ergodicity. In order to improve the search ergodicity, we develop a particle swarm optimization algorithm with a non-linear decreasing inertia weight and Metropolis criterion, which is more suitable for unknown variables with complex probability density functions. The recognition results are obtained simultaneously when the iterative process terminates. We assess our proposed approaches based on a hypothetical case study at a three-dimensional site contaminated with DNAPLs. The results demonstrate that the parallel heuristic search strategy is helpful for the simultaneous recognition of DNAPL contaminant sources in groundwater and aquifer parameters.

Quantitative PCR (qPCR) is the method of choice for specific detection and quantification of harmful algal bloom (HAB) species. Development of qPCR assay for simultaneous enumeration of species that frequently co-exist in HABs is required. A high sensitivity TaqMan qPCR assay, using probe and primers, located at ITS1–5.8S–ITS2 rDNA region, detecting, specifically, Karenia selliformis, K. bidigitata, and K. mikimotoi, was designed. ITS1–5.8S–ITS2 rDNA region copy numbers per Karenia cell genome were estimated to 217.697 ± 67.904, allowing cell quantification. An application of the designed methodology in field samples has been conducted, and it showed high sensitivity (detection of around 10⁻¹ cell/100 mg of bivalve mollusk tissue, equivalent to about 20 copies of the target sequence). We suggest that the optimized method could contribute to early detection of three closely related Karenia species in seafood cultivating areas to promote control quality, guarantee a fast and effective intervention, and improve public health prevention.

Political corruption is considered one of the major obstacles to achieving high-quality economic development in developed and developing countries. This study first calculates the ecological footprints of 29 provinces in China based on China’s provincial panel data from 2006 to 2015. The provinces’ ecological efficiencies were then calculated. The relationship between government corruption and ecological efficiency is researched, and the result shows that such a relationship is not linear. At different levels of ecological efficiency, government corruption has different effects on ecological efficiency. Finally, the resource misallocation index is introduced, and the spatial error model is used to further test the impact of government corruption and resource misallocation on ecological efficiency. The regression results show that high levels of government corruption and resource allocation distortion will cause a decrease in regional ecological efficiency, which adversely affects the sustainable development of the economy.