Due to many uses of zinc oxide nanoparticles (ZnO NPs) in various industries, the release of these particles in the environment and their effects on living organisms is inevitable. In this study, the role of salicylic acid (SA) pretreatments in modulating the toxicity of ZnO NPs was investigated using a hydroponic system. After pretreatment with different concentrations of SA (0, 25, 75, and 150 μM), Chenopodium murale plants were exposed to ZnO NPs (50 mg L⁻¹). The results showed that exogenous SA increased the length, weight, chlorophyll, proline, starch, and soluble sugars in the plants. Besides, SA pretreatments improved water status in the plants treated with ZnO NPs. In SA-pretreated plants, increased activity of catalase (CAT), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) was associated with a decline in electrolyte leakage (EL %) and membrane peroxidation. Under NPs stress, SA pretreatments increased the content of phenolic compounds by increasing the activity of phenylalanine ammonia-lyase (PAL). Exogenous SA reduced the translocation of larger amounts of Zn to the shoots, with more accumulation in the roots. This result can be used to produce healthy food from plants grown in environments contaminated with nanoparticles. It seems that all concentrations of SA reduced the symptoms of ZnO NPs toxicity in the plant by strengthening the function of the antioxidant system and increasing the content of some metabolites. Findings also suggest that SA pretreatment can compensate for the growth reduction caused by ZnO NPs.

The construction projects and activities generate waste materials, which impose negative impacts on the environment and contribute towards environmental degradation. In this regard, the implementation of environmental practices (EPs) can play a vital role in reducing the environmental risks associated with waste materials from construction projects. Based on this hypothesis, the present survey study was conducted to assess the effectiveness of different EPs in reducing environmental risks associated with waste materials from construction firms (n = 159) operating in Pakistan. Organizational and government support, regulatory pressure, and economic and environmental performance were among the main determinants of EPs studied in the present study. The partial least squares technique was used for the data collection, assessment, and prediction of the results based on the hypothesis testing for a range of determinants. Compose reliability analysis of determinants showed that all items gave a value of 0.7, which is a clear indication of the reliability of each determinant in the formation of the hypothesis. From all eight hypotheses, H₁ (0.475), H₄ (0.217), H₆ (0.114), H₇ (0.210), and H₈ (0.149) hypotheses with size effect in parentheses were acceptable due to their positive construction with EPs, while H₂, H₃, and H₅ hypothesis did not show the significant effect with size effect values lower than 0.1. The study demonstrated that current environmental regulations and governing bodies in Pakistan are not sufficiently effective and strict to implement environmental regulations. In this regard, regulatory pressure is necessary to promote EPs along with increasing stakeholders’ awareness. Overall, the implementation of EPs not only prepares construction firms to deal with the pressure exerted by regulations and customers but also enhances the environmental and economic performance of construction firms.

Karenia selliformis is a marine dinoflagellate responsible for fish-kill events. Its presence has been reported along the Tunisian coasts (south-eastern Mediterranean Sea) since the 1990s. In the present study, a quantitative-PCR assay, based on the internal transcribed spacer (ITS) molecular marker, was developed to detect and quantify K. selliformis in environmental bivalve mollusk samples and in seawater samples. The assay was optimized, and its specificity was confirmed using cross-reactivity experiments against microalgal species commonly found on the Tunisian coasts and/or closely related to K. selliformis. Calibration curves were performed by tenfold dilutions of plasmid DNA harboring target sequence and genomic DNA, attaining a limit of detection of around 5 copies of target DNA per reaction, far below one K. selliformis cell per reaction. The field application of the developed assay showed a powerful detection capability. Thus, the designed assay could contribute to the deployment of in-field diagnostic tools for K. selliformis blooms monitoring.

Octafluorocyclobutane (C₄F₈) with a GWP₁₀₀ (global warming potential) of 10,000 times of CO₂ is listed as potent greenhouse gas. Therefore, development of effective control technologies for reducing C₄F₈ emissions has become an emerging issue to be addressed. In this study, decomposition of C₄F₈ was investigated via three systems including catalytic hydrolysis, non-thermal plasma, and plasma catalysis, respectively. Decomposition of C₄F₈ achieved with catalytic hydrolysis reaches the highest efficiency of 20.1%, being obtained with γ-Al₂O₃ as catalyst in the presence of 10% H₂O₍g₎ and operating temperature of 800 °C. For plasma-based system, the highest C₄F₈ conversion obtained with non-thermal plasma is 62% at a voltage of 23 kV. As for the plasma catalysis system, 100% C₄F₈ conversion efficiency can be achieved at an applied voltage of 22–23 kV. The effects of various parameters such as gas flow rate and C₄F₈ concentration on plasma-based system show that the plasma catalysis also has better resistivity for the high gas flow rate. The highest energy efficiency of 0.75 g/kWh is obtained for the gas flow rate of 500 mL/min, with the C₄F₈ conversion of 41%. The highest conversion 89% was achieved with the O₂ content of 0.5%. Addition of Ar improves the performance of plasma-based system. When Ar is controlled at 20%, C₄F₈ conversions obtained with plasma catalysis reach 100% at applied voltage of 22–23 kV even in the presence of 5% O₂. The main products of the C₄F₈ conversion include CO₂, NOₓ, and COF₂ when O₂ is added into the system. As water vapor is added, HF is also formed. This study has confirmed that combined non-thermal plasma with catalyst system to convert C₄F₈ is indeed feasible and has good potential for further development.

Proper disposal of the millions of tons of eggshell waste generated around the world every year is a significant environmental challenge. However, eggshell waste can be converted into new materials that may be useful for a wide range of applications. In this study, four methods, including the conventional subcritical hydrothermal method (CSHM), microwave-assisted subcritical hydrothermal method (MSHM), conventional low-temperature hydrothermal method (CLHM), and ultrasonic-assisted low-temperature hydrothermal method (ULHM) were used to convert eggshell waste into hydroxyapatite (HAP). For each hydrothermal method, increasing the reaction temperature increased production efficiency and improved the degree of crystallinity of HAP. X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the preferred eggshell-derived HAP, which was produced by the MSHM at 180 °C in a period of only 1 h. For the MSHM, the HAP yield was 75.3%, the degree of HAP crystallinity was as high as 0.78, and pure, rod-like, nano-sized HAP particles with high specific surface area were produced. For the preferred HAP produced by the MSHM, the adsorption capacity of Pb²⁺and pH were positively related in the range of pH 1–6. Consequently, the HAP produced by the MSHM showed relatively high maximum adsorption (qₘ= 505.05 mg/g) of Pb²⁺ in aqueous solution. The adsorption process followed a pseudo-second-order reaction model, and the equilibrium adsorption was well fit by the Langmuir model.

Air pollution these days could cause severe effects on human health. As human health is crumbled with serious respiratory or other lung diseases, it is prominent to study air pollution. One of the ways to address this issue is by applying clustering techniques. The two main important problems that are faced in the clustering algorithm are, firstly, the exact shape of the cluster and the number of clusters that input data can produce. Secondly, choosing an appropriate algorithm for a particular problem is not clearly known. Finally, multiple replications of the same algorithm lead to alternative solutions due to the fact such as random initialization of cluster heads. Ensembling algorithms can handle these problems and overcome bias and variance in the traditional clustering process. An adequate study has not been carried out in the ensembling approach mainly for clustering. In this paper, we use an enhanced ensemble clustering method to cluster the pollution data levels. This study helps to take preventive measures that are needed to control further contamination, reduce the alarming levels, and analyze the results to find healthy and unhealthy regions in a given area. This ensemble technique also explains about uncertain objects that are found in clustering. The distinct advantage of this algorithm is that there is no requirement of prior information about the data. This experiment shows that the implemented ensemble consensus clustering has demonstrated improved performance when compared with basic clustering algorithms.

An innovative method for utilizing synthetic calcium fluoride (CaF₂), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H₂SO₄) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via reaction of synthetic CaF₂ and waste H₂SO₄. The impact of four factors, including H₂SO₄ concentration, total volume (H₂SO₄ + H₂O)/CaF₂ ratio, drying temperature of synthetic CaF₂, and reaction carried out under different temperature, on HF productivity was investigated in this study. HF yield increased with increasing H₂SO₄ concentration and total volume/CaF₂ ratio under room temperature. Generally, reactions carried out under low-temperature (< 100 °C) had a positive impact on HF yield. The higher temperature led to an increase in absorbed-HF but a decrease in total-HF. The reaction of commercial CaF₂ and 70% H₂SO₄ had a higher absorbed-HF yield of 61.7% than synthetic CaF₂ and 70% waste H₂SO₄, which had a yield of 36%. This was due to the higher purity of the commercial CaF₂ and fewer interference ions in H₂SO₄. HF productivity was lowered by CaSO₄, which hindered the reaction of reactants and also the generation of fluorosulfuric acid.

Plastic debris sized from 0.33 to 5 mm or so-called microplastic is an abundant environmental pollutant found worldwide in various ecosystems. The contamination has been threatening animals such as fish, wild birds, domesticated poultry, and waterfowls. This preliminary research aimed to reveal the evidence of microplastic contamination in domesticated duck to prove that plastic contamination has spread massively and depicts how far the local duck ingests microplastic. Total 25 duck samples were collected from local duck intensive husbandry in five cities, i.e., Semarang and Pati (coastal area), Salatiga (lowland area), and Temanggung and Magelang (highland area). Duck intestinal tract samples were collected and were further digested using 10 N KOH at 60–80 °C for 24 h. The mixture was then collected into vial tubes and was centrifuged to get the pellet. The microplastic identification was conducted using a stereo microscope based on its size and shape. Based on the observation result, microplastic debris in the form of the filament was 49, 39, and 27 per individual in the duck sample from Salatiga, Semarang, and Magelang, respectively. The ingestion of plastic may come from duck feed, such as rough fish (mainly were obtained from the Java Sea) and water. This finding is essential to disseminate since microplastic contamination can be transferred from animals to humans and threaten health. Also, this result can contribute to policymakers deciding on plastic reduction.

This study aimed to investigate the concentration of 33 pesticide residues in 60 black tea samples collected from Iran, determine their transfer rate, and assess their health risk during brewing. Pesticide extraction and analysis were performed by using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and gas chromatography/tandem mass spectrometry (GC-MS/MS), respectively. The limits of detection (LOD) and the limits of quantification (LOQ) of pesticides were ranged 0.1–7.26 and 0.8–24 μg/kg for dried tea leaves and 0.03–3.1 and 0.09–10 μg/L for the tea infusion, respectively. The levels of pesticide residue in 52 (86.67%) out of 60 tea samples were above the LOD (0.1–7.26 μg/kg). Twenty four (40%) of the samples contained pesticides in a concentration higher than the maximum residue limit (MRL) set by the European Commission (EC). Seven out of 33 validated pesticides were detected in dried tea leaf samples that only four of seven, including buprofezin, chlorpyrifos, hexaconazole, and triflumizole, were transferred into tea infusion, demonstrating that the concentrations of pesticides in infusion were raised during brewing. The risk assessment study for detected pesticides in the tea infusion samples indicated that this beverage consumption was safe for consumers, while the mean residue of some pesticides in positive samples was higher than the MRL; therefore, periodic control of these pesticides should be regularly implemented.

Cultivation of desert cyanobacteria in wastewater can lead to the optimal redistribution of regional resources and is likely to solve two global problems, i.e., wastewater pollution and desertification. However, the potential of using wastewater instead of traditional artificial culture media to cultivate sand-consolidating cyanobacteria for desert management is not well understood. This study compares undistilled and distilled wastewater with an artificial culture medium (BG11₀) to explore the potential of wastewater as a replacement culture medium for Scytonema javanicum. The results show that the photosynthetic activity (Fᵥ/Fₘ) of S. javanicum was inhibited in the undistilled wastewater and was lower than that in distilled water and the culture medium. The lowest Chl-a concentration and the highest concentration in BG11₀ were found in distilled wastewater. However, there was no difference in the biomass (dry weight) between the undistilled wastewater and BG11₀ at the end of the experiment. After long-term dry storage of the biomass collected after cultivation, there was no difference in the photosynthetic recovery between S. javanicum cultivated in undistilled wastewater and that cultivated in BG11₀. Accordingly, although wastewater depressed the Chl-a content, it did not affect the biomass accumulation and subsequent photosynthetic recovery after long-term storage. The results reveal the significant potential of cultivating sand-consolidating cyanobacterium in wastewater and using this technology as a new nutrient redistribution method in human settlements and desert areas.