The salt obtained from salt sources has a low purity level and contains contaminants. The primary contaminants in the brines were eliminated in this investigation by using analytical separation (titration) techniques. Following the purification method, sodium hydroxide (NaOH) was added to magnesium chloride (MgCl2) to make magnesium hydroxide (Mg(OH)2) coagulate in pH control. This was done by PID and Self-Tuning PID (STPID) Control. Using STPID Control, hydrochloric acid (HCl) at a rate of 20% was employed as an effective acid current, MgCl2 as a coagulant, and NaOH at a rate of 10% as a neutralization base throughout the process. The coagulation technique was carried out with pH values of 7, 9, and 11, respectively. The pH of the medium was adjusted using the PID and STPID algorithms, as well as an on-line computer control system. As the system model, ARMAX was employed. As a forcing function, a pseudo-random binary sequence (PRBS) was used to identify the dynamics of the process to be controlled, and the system output was measured. The Bierman algorithm was used to evaluate the model parameters. The STPID controller's tuning parameters were calculated. Following the coagulation method, an analytical titration procedure was used to find out if there are any trace amounts of Mg(OH)2 in the current environment, and a settlement percentage of 90% to 95% was found. To get the best coagulation, a pH value of 11 was chosen as the optimal value based on the performed calculations.

The impact of atrazine and nitrate, the most used pesticide and fertilizer, on the health of Sclerophrys regularis was investigated in this study. We exposed the tadpole of Sclerophrys regularis to atrazine and nitrates to assess abnormalities and genotoxicity as biomarkers for environmental impacts. The proportional malformed toads were shown to be high when treated with nitrate alone (17%) or in combination (13%) or even treated with atrazine alone (the minimal, 5%), limbs and tail deformities are the most observed. Also, abnormal activity and movement were detected at all treated groups. In addition, Genotoxicity was measured by micronucleus test (MN) in detection of nuclear abnormalities in given species. The results indicate that individuals exposed to atrazine or nitrate or that exposed to both, exhibited a significantly higher degree (p < 0.01) of nuclear lesions. These results constitute key assessment of developing abnormalities and MN test in this species in Egypt and suggest that developing abnormalities and /or MN test and the degree of nuclear lesions of RBCs can be a useful indicator of the degree of environmental stress and ecosystem disrupting experienced by amphibian populations.

This study derives an analytical solution of a one-dimensional (1-D) Advection-Dispersion Equation (ADE) for solute transport with two contaminant sources incorporating the source term. Groundwater velocity is considered as a linear function of space while the dispersion as a nth power of velocity and analytical solutions are obtained for , and . The solution is derived using the Generalized Integral Transform Technique (GITT) with a new regular Sturm-Liouville Problem (SLP). Analytical solutions are compared with numerical solutions obtained in MATLAB pedpe solver and are found to be in good agreement. The obtained solutions are illustrated for linear combination of exponential input distribution and its particular cases. The dispersion coefficient and temporal variation of the source term on the solute distribution are demonstrated graphically for the set of input data based on similar data available in the literature. As an illustration, model predictions are used to estimate the time histories of the radiological doses of uranium at different distances from the sources boundary in order to understand the potential radiological impact on the general public for such problem.

The article presents the results of a study of heavy metals in snow and groundwater within the industrially developed Arkhangelsk agglomeration, which is the largest among urban formations in the Arctic zone of Russia. This article describes the results of research on the territories of three suburban community garden plots used by residents of the cities of the Arkhangelsk, Severodvinsk and Novodvinsk agglomeration for recreation, growing fruits and vegetables, picking wild berries and mushrooms, and short-term residence. In groundwater samples taken from wells, the average concentrations of heavy metals decrease in the following order: Fe > Mn > Zn > Cr > Ni > Cu > Ti > V > Pb > U > As > Co > Mo > Sb > Cd. A comparison of metal concentrations in groundwater with WHO and SanPiN standards showed that only Fe and Mn exceeded the permissible limits, for the rest of the studied metals, the concentrations were significantly below the permissible limits. The study of heavy metals in the snow showed a similar order of decrease in concentrations to groundwater and total concentrations of soluble metal fractions. This fact indicates the migration of heavy metals into groundwater after the spring snowmelt and the fact the main source of groundwater pollution is the atmospheric channel. According to the values of the total areal pollution of the snow cover with heavy metals, the most polluted are suburban garden plots in the area of the Arkhangelsk city – 216.91 mg/m2. The results of the principal component analysis showed that the main sources of snow cover pollution with heavy metals in the suburban areas of the Arkhangelsk agglomeration were thermal power plants, machine-building and metallurgical plants, a solid waste landfill, and vehicles. The calculation of the heavy metal pollution index for water did not reveal a significant anthropogenic impact. However, the indices assessing the amount of metals (heavy metal evaluation index), toxicity (heavy metal toxicity load), non-carcinogenic risk (hazard index), and carcinogenic risk indicate a high level of heavy metal pollution of the studied waters, as well as the unsuitability of groundwater and melted snow as drinking water. Metals such as Fe, Mn, Ni, Cu, and Pb make the greatest contribution to the quality indices of the studied waters.

Air pollution is a significant concern for both managers and disaster decision-makers in megacities. Considering the importance of having access to correct and up to date spatial data, it goes without saying that designing and implementing an environmental alerting and monitoring system is quite necessary. A standard infrastructure is needed to utilize sensor observations so as to be ready in case of critical conditions. The use of sensor web is regarded a fundamental solution to control and manage air quality in megacities. The proposed system uses the SWE framework of OGC, the reference authority in spatial data, to integrate both sensors and their observations, while utilizing them in the spatial data infrastructure. The developed system provides the capability to collect, transfer, share, and process the sensor observations, calculate the air quality condition, and report real-time critical conditions. For this purpose, a four-tier architectural structure, including sensor, web service, logical, and presentation layer, has been designed. Using defined routines and subsystems, the system applies web sensor data to a set of web services to produce alerting information. The developed system, which is assessed through sensor observation, measures the concentration of carbon monoxide, ozone, and sulfur dioxide in 20 stations in Tehran. In this way, the real-time air quality index is calculated, and critical conditions are sent through email to those users, who have been registered in the system. In addition, interpolation maps of the observations along with time diagrams of sensors’ observations can be obtained through a series of processes, carried out by the process service.

The present study simulates the frontal dust storm by means of WRF-Chem model and AFWA emission scheme between April 23 and 24, 2019. It then applies reanalysis data (ERA5) to analyze this case from a synoptic perspective. The simulation results show that the model have been accurately characterized first by the onset of dust from the south-east of the country in Kerman Province and then via its transmission to large areas of the east and south-east. The model output also fits well with satellite images. A quantitative comparison of PM10 concentration of the model with actual values shows that the PM10 model estimates are larger than actual values, though it predicts the trend of concentration changes well. Examining the synoptic maps, the isobars’ curve, wind direction change, and temperature advection in the area reveals the presence of atmospheric fronts within a strong dynamic low-pressure system. This causes high temperature and pressure gradients, in turn speeding up the wind within the region. Results from the synoptic analysis show that by passing the frontal system and behind the cold front, a dust mass is formed, which gradually spreads in eastern and the southeastern regions of Iran. In this case, extreme pressure gradient, cold front passage, low-level jet, wind gust on dry areas of dry Hamoon wetland, and cold air advection over flat area of the Lut Desert are important factors in storm formation and emission, east of the country.

Because of the pinch of air pollution on human health and its environment, it has become necessary to monitor and map out the peaks and lows threat places of air pollution in different land use across a city. In this regard, air pollution exposure mapping of Kano metropolis based on land use classifications namely industrial, residential, commercial and institutional was carried out for interpretive and assessment of health hazard associated with the selected pollutants. The observations for ambient air quality parameters (CO, SO2, H2S, NO2, and PM10) monitored with portable digital air pollution detecting devices for creation of data. Geographic Information Systems (GIS) technique was applied to create spatial distribution maps of urban air quality of the metropolitan area. The results of pollution index map of ArcGIS extrapolation indicated that neighbourhoods in the vicinity of Bompai and Sabon Gari industrial and commercial zones, respectively were found to be highly exposed and liable to ailments associated with air pollution, while places nearby Dorawa and School of Technology were air pollution-ease zones but could experience bioaccumulation over long exposure time. Therefore, the study reveals that variability of air quality was strongly related to predominant land use in particular areas within the metropolis and could help in estimate and valuation of likely health challenges associated with poor air quality due to air pollution. Besides, the observed spatial variation for air quality could serve as hot spot identifier and as an informant for rational decision on air quality control strategies for environmental management.

This study investigated the evolutionary history of the Late glacial in number of wetlands in south part of Lake Urmia. Twenty-six cores with a maximum depth of 12 m, average 8 m and total depth of about 190 m were collected from sediments under the southern and southwestern wetlands using a handi auger. Sedimentary facies were identified and separated based on sediments texture and structure, composition of evaporite minerals and organic materials, also color and other macroscopic elements. The results indicated the presence of eight distinct sedimentary facies belonging to the lacustrine, wetland and fluvial (river) sedimentary environments. In the last 20 cal ka BP, the two dominant dry periods, about 4 cal ka BP and 13 cal ka BP, have been associated with the transgression of dry (alluvial) facies towards the lake and the regression of Lake facies. The dry period 4 cal ka BP affected the southern part of Lake Urmia and marginal wetlands, while the dry period 13000 years ago was more intense and longer and lasted at least 3 cal ka BP.In the last 2cal ka BP, the two dominant dry periods, about 4 cal ka BP and 13 cal ka BP, have been associated with the transgression of dry (alluvial) facies towards the lake and the regression of Lake facies. The dry period 4 cal ka BP affected the southern part of Lake Urmia and marginal wetlands, while the dry period 13000 years ago was more intense and longer and lasted at least 3 cal ka BP.

Manufactured nanoparticles (NP) have caused extreme concern about their ecotoxicological effects on the marine systems. In this study, we investigated the biological effects (oxidative stress and genotoxic response) of TiO2-NP at predicted environmental relevant concentrations (0.2 mg/l and 1 mg/l) on marine mussel Mytilus trossulus a dominant member of the far eastern coastal community. The results of the experiment revealed that TiO2-NP when suspended in seawater, formed agglomerates ranging from 400 nm to several μm in diameter. However, TiO2-NP caused obviously oxidative damage on the mussel as evidenced by the significant elevated levels of malondialdehyde (MDA) in the gill and digestive gland. The genotoxic potential of TiO2-NP was assessed by comet assay, which detect primary DNA damage. The gill and digestive gland cells showed significantly enhanced DNA damage for both concentrations of TiO2-NP compared to the control group. These results propose that the TiO2-NP are entering the marine coastal waters can cause genotoxic effect on mollusks and comet assay can be successfully applied as an effective tool for risk assessment of NP on the marine invertebrates. The findings of this study demonstrate that the aggregation of TiO2-NP does not reduced of NP ecotoxicity, but only changes the biological responses.

The Indoor Air Quality (IAQ) of a hospital is very important to properly protect both patients and the staff against hospital infections. The present study aims at evaluating the efficiency of photocatalytic filters as well as the impact of important factors such as the type of UV wavelength (UVC, UVA) with different intensities and loading rates of TiO2 in HEPA Filters on reducing airborne microorganisms. For so doing, it has prepared photocatalytic filters by dipping them into 2% and 4% titanium dioxide suspensions as low and high loading, respectively. The experiments have been carried out on four species’ microorganisms, namely Epidermidis, Subtilis, Niger, and Penicillium. Fungi and bacteria suspensions have been prepared with concentrations of 106, 107 CFU/m3, respectively. In terms of microorganism removal, the efficiency of HEPA filters in both types of TiO2 loading and UVC and UVA radiations with two intensities at three times intervals (60, 90, and 120 min) have been investigated. Results show that lower penetration microorganism belong to PCO (TiO2 + UV), compared to photolysis (UV alone) at all intervals of UV radiation. TiO2 loading has no significant effect on percentage removal in all microorganisms. The percentage penetration of microorganisms under UVC radiation is lower than UVA radiation. Also, increasing the radiation intensity in both types of UV shows that it has higher effectiveness for removing bacteria and fungi. Therefore, the use of photocatalytic HEPA filters with UVC radiation can play an influential role in reduction of the microorganisms in different places such as hospitals, cleanrooms, etc.