In this study, a multitude of statistical tools were used to examine PM10 concentration trends and their seasonal behavior from 2015 to 2021 in Tehran. The results of the integrated analysis have led to a better understanding of current PM10 trends which may be useful for future management policies. The Kruskal – Wallis test indicated the significant impact of atmospheric phenomena on the seasonal fluctuations of PM10. The seasonal decomposition of PM10 time series was conducted for better analysis of trends and seasonal oscillations. The seasonal Mann-Kendall test illustrated the significant possibility of a monotonic seasonal trend of PM10 (p = 0.026) while showing its negative slope simultaneously (Sen = -1.496). The forecasting procedure of PM10 until 2024 comprised 15 time series models which were validated by means of 8 statistical criteria. The model validation results indicated that ARIMA (0,1,2) was the most satisfactory case for predicting the future trend of PM10. This model estimated the concentration of PM10 to reach approximately 79.04 (µg/m3) by the end of 2023 with a 95% confidence interval of 51.38 – 107.42 (µg/m3). Overall, it was concluded that the use of the aforementioned analytical tools may help decision-makers gain a better insight into future forecasts of ambient airborne particulate matter.

Today, the application of supercritical fluid extraction (SFE) has been the focus of many researchers in various industries due to suitable operating conditions, environmental friendliness (no use of organic solvents) and high efficiency. In this process, a solvent is used for separation in supercritical conditions. Pharmaceutical, oil extraction, and oil and gas industries have conducted extensive research in this field. Electronic and electric devices are constantly being upgraded and updated due to the rapid advancement of science and technology, which creates a number of issues with handling electric and electronic waste (e-waste). The most significant issue is that it is challenging to safely dispose of halogen flame retardants and refractory polymers in e-waste. Supercritical fluid (SCF) techniques provide significant environmental benefits over previous disposal methods like pyrolysis and acid leaching since they pose no dangers for air or water contamination. This study discusses and provides a summary of the basic concepts and appropriate factors of supercritical fluid extraction (SFE). SCF methods were claimed to have recovered precious metals, base metals, and other inorganic minerals from e-waste with a recovery efficiency of further 93%. This study reviews the recent advances in supercritical water (SCW) and supercritical carbon dioxide (SCCO2) extraction technologies for metal recovery from e-wastes. On the other hand, hybrid technologies are significantly improving in this field which could be considered for future studies.

As natural corridors, urban rivers are often under ecological pressures disturbing their environmental functions, and services over time and space. The landscape services (LS) has been accordingly introduced as an alternative method to evaluate such functions at the landscape scale. In this regard, public perceptions can seriously shape landscape changes, with potentially consistent or inconsistent implications for ecosystem sustainability over time and space. To shed light on this issue, the present study aimed to evaluate the LS of the Mehranrood River running through the city of Tabriz, Iran, from local users' perspective. For this purpose, approximately 365 questionnaires (with the Cronbach's alpha coefficient equal to 0.97) were developed based on the LS indicators and completed by the stakeholders. To analyze the results, structural equation modeling was applied. Afterward, the accuracy of the given model was checked by applying the root-mean-square error of approximation (RMSEA). The results showed that the service provision accounted for the largest number of factors. The cultural services were completely dependent on the presence of production/supply and regulation/maintenance services. The study results demonstrated that, the river had no efficient structures and functions from the stakeholders' perspective. They even believed that the ecological restoration of the Mehranrood River could deliver the potential ability to enhance its LS. Moreover, the respondents were willing to be in close contact with the river if it could be ecologically rehabilitated. Generally, ecological restoration could help boost urban resilience over time through the regeneration of ecological infrastructure, which required a transition from mechanical to ecological thought.

This article presents that the coagulation-flocculation process is one of the water treatment processes that mainly removes dyes from aqua solution by using chemical and natural coagulants. This research was conducted to evaluate the use of chemical coagulants (ferric chloride (FeCl3), aluminum chloride (AlCl3) and natural coagulant (okra pods) to remove Vat Green 3 (VG 3) dye from aqua solution by the coagulation-flocculation process. Various experimental parameters were studied by jar test experiments such as pH, coagulant dosages, initial VG 3 dye concentration, mixing speed, and settling time. The results showed that the maximum removal efficiency of VG 3 dye was for FeCl3 97.261%, AlCl3 94.466% and okra pods 92.572% at optimum conditions pH 6 for FeCl3 and okra pods, pH 7 for AlCl3, coagulant dosage 400 mg/L for FeCl3 and AlCl3, 200 mg/L for okra pods dosage, concentration of dye 80 mg/L, mixing speed 150 rpm, and settling time 60 min for FeCl3 and AlCl3, 70 min for okra pods at room temperature 25 ± 2 oC. The maximum volume of sludge at optimum conditions was 33 mL/L, 20 mL/L, 3 mL/L for FeCl3, AlCl3, okra pods, respectively. The kinetics of the coagulation-flocculation process was obeying pseudo first order kinetics more than pseudo second order kinetics. These results indicated that the natural coagulant (okra pods) could be an alternative to chemical coagulants for removal of VG 3 dye from textile effluent due to its low cost, biodegradable, non-polluting and lower sludge production.

This article provides an overview of the main findings of a survey on the effects of ambient temperature and humidity on vehicular emissions of criteria pollutants and greenhouse gases. The present study is focused on the emissions of Carbon Monoxide (CO), Nitrogen Oxides (NOX), Sulfur Oxides (SOX), Particulate Matters (PM), Carbon Dioxide (CO2), Nitrous Oxide (N2O), and Methane (CH4) from gasoline engine passenger cars. In this analytical research, the International Vehicle Emissions (IVE) model was operated, using long-term meteorological data to determine the effects of various ambient temperature and humidity levels on exhaust pipe pollutants and greenhouse gas emissions. The results of present study indicated that as the ambient temperature increases from -7.5 °C to 20 °C, CO, NOX, and CH4 emissions decrease by 35.8%, 6.46%, and 21.44%, respectively, while SOX, PM, CO2, and N2O emissions remain constant. In contrast, increasing the ambient temperature from 20 °C to 37.5 °C increases the emissions of all the investigated pollutants and greenhouse gases. On the other hand, the findings showed that as the ambient humidity increases from 8% to 98% CO and CH4 emissions increase by 7.3% and 2.13%, respectively; while NOX emissions decrease by 16.84%. However, humidity changes did not have noticeable impact on the emissions of SOX, PM, CO2, and N2O. This study concluded that changes in meteorological parameters over a certain period of time, not only affect global warming, but also the emissions of criteria pollutants.

Cold plasma has emerged as a powerful energy-efficient and environmentally friendly advanced oxidation technique in recent decades as a non-thermal approach in a wide range of applications. It is a form of plasma that is created at low temperatures and can be used for various applications, including water treatment This study aims to determine the influence of Cold plasma treatment on endotoxin reduction in dialysis water. A lab-scale unit was built to implement the experiments and synthetic water (feed solution) was prepared with a known level of endotoxin (0.48 EU/mL). The test for Limulus amebocyte lysate was used to assess concentrations of endotoxin in treated water. The experimental results showed reduce of endotoxins in the cold plasma treatment. This type of treatment reduced the concentration of endotoxin to 0.17 ± 0.09 EU/ml. The results of the study indicated that this could be an innovation in cold plasma jet fields, with numerous applications in dialysis fluid preparation.

Biomass extracted from different plant parts can play a role as a cheap, efficient and eco-friendly adsorbent. In this research, Lantana Camara L. Stem biomass (LSB), a low-cost and useless material, was introduced as efficient biomass for divalent zinc biosorption from aqueous environments. For achieving optimal conditions in the zinc biosorption process, the experimental design was applied by the response surface methodology (RSM) based on a Box-Behnken design (BBD) model. Based on the comparison between the measured and predicted amounts, the values of R2,Radj2, and Rpred2 in the Zn(II) biosorption model were 0.9960, 0.9887 and 0.9441. The Zn(II) uptake in the experiments, BBD model-based (p-value of Lack-of-Fit term = 0.228 > 0.05), varied from 15.19% to 81.11%. The maximum analyte uptake at a LSB-to-Zn(II) ratio of 8:1, synthetic solution pH of 6.5 and residence time of 75 min was predicted at 97.12%. The maximum Z.R.% based on the validation test performed based on the optimal predicted conditions was also obtained at 94.65%, which is 2.5% different from the model's data amount, confirming the acceptable accuracy of the quadratic model. The LSB, in optimized conditions, as a low-cost biosorbent, can be a suitable candidate with acceptable potential for heavy metals biosorption from aquatic solutions.

Environmental pollution has become and increasing concern due to growing risk to human health. Soil pollution is an aspect of environmental pollution that has received comparatively less attention than water pollution. However, considering direct effects of contaminants transmission through ingestion to the human body, it can lead to greater risks for human health. Arsenic is a highly prevalent environmental pollutant, and considerable number of people worldwide suffer from constant exposure to it. While there are several ways to manage and remediate contaminated soils, phytoremediation has been paid special attention due to its higher social acceptability and lower cost. Nevertheless, this approach faces challenges, including effectively handling significant quantities of contaminated biomass, managing it appropriately, and selecting suitable plant species for the remediation process. In this regard, numerous endeavors have been undertaken to tackle these obstacles like strategies encompass the utilization of amendments, adept management of biomass, and the implementation of hybrid remediation approaches. This study aims to review prior research on mechanisms, challenges, and enhanced phytoremediation of arsenic-contaminated soils, encompassing reduction of contaminated biomass after phytoremediation.

In the framework of a project aiming to phytoremediate contaminated soils with heavy metal Cr in Long Khanh city, Dongnai province, Southeast of Vietnam, a series of greenhouse experiments followed by field trials were performed in order to evaluate the effect of L. sphaericus on the Cr phytoextraction by S. nigrum. The results showed that L. sphaericus improved the Cr uptake efficiency of S. nigrum through changing growth parameters such as root length, height, biomass and the ability to accumulate Cr in plants. At an application rate corresponding to the T3 treatment in this experiment, L. sphaericus can stimulate the dry biomass of S. nigrum by 143%, increase the Cr concentrations in the aerial part by 70%, the content of Cr extracted in a single plant up to 293% compared to treatment without L. sphaericus.

In order to find an effective decolorization method for dye wastewaters, the present work aims at studying the treatment efficiency of an azo dye Acid Red 14 (AR14) by Electro-Fenton process using an undivided electrochemical cell containing different electrode materials. The optimal removal efficiency was obtained using carbon felt or glassy carbon (cathode) and platinum (anode) electrodes. The method is based on the reaction of electrochemically produced hydroxyl radicals leading to oxidative degradation of the AR14. To find the best conditions for treatment of AR14 dye, the effects of Fe2+ concentration, current density, the effect of pH initial, and the nature of support electrolyte were studied. The results showed 94 % removal efficiency in 30 minutes with 120 mA/cm2 of electrolysis current, 0.2 mM of Fe2+, and pH = 3. However, the decolorization efficiency measurements confirmed that the Electro-Fenton process with the platinum anode and the carbon felt cathode was more efficient.