The present study aims to provide baseline information on the temporal characteristics of PM2.5 and PM10 concentration time series variations, mainly on the cross-correlation between PM2.5 and PM10, using the improved mathematical and nonlinear methods. Firstly, the fractal theory such as fractal dimension is used to detect the pollution level in PM2.5 and PM10 time series. Secondly, the Multifractal Detrending Moving-Average Analysis (MFDMA) is used to analyze the multifractal characteristics of PM2.5 and PM10 concentrations. Thirdly, Multifractal Detrending Moving-Average cross-correlation Analysis (MFXDMA) is used to study the cross-correlation between PM2.5 and PM10 concentrations measured from January 1 to December 31, 2020, along the Boulevard de la Marina, one of the major roads in Cotonou. The results have indicated that: (1) PM10 and PM2.5 concentration time series are characterized by a fractal dimension, which can permit to detect the pollution levels and to analyze the differences in emissions sources; (2) there is a significant multifractal structure in the PM2.5 and PM10 concentration data and their fluctuations are long-range correlated, however, the multifractal properties and self-memory characteristics change with the months; (3) generally, the multifractal degree and the complexity of PM10 are much stronger than those of PM2.5. However, they present a similar multifractality degree in some months of the year; (4) except, in February, the cross-correlation between PM2.5 and PM10 time series in the months of the year presents multifractal characteristics with positive persistence; (5) the cross-correlation multifractal features show monthly variation. This paper provides the inter-relationship between air PM2.5 and PM10 time series which may help taking steps in controlling the air quality and management of the Cotonou port area environment.

In this study, the concentrations of heavy metals were studied using atomic absorption spectroscopy of samples from the sediments of the Tigris River within the boundaries of the city of Mosul, northern Iraq, and the environmental parameters of heavy metals were calculated. The results showed that the average concentrations of Co, Cu, Cd, Pb, Zn, and Ni in (ppm) were (8.78, 30.42, 0.179, 12.04, 75.53, and 144.75), respectively, where these results were higher than the international accepted average. It indicates that the main factor in the high concentrations of heavy metals in the environment of the Tigris River in the city of Mosul is the pollution caused by human activities. The results of the environmental treatments for the studied heavy metals showed that the values of the enrichment factor (EF) were moderately contaminated with Cu, Cd, Ni, and Zn and not contaminated with Co and Pb. The value of the contamination factor (CF) for the sediments of the Tigris River in the studied areas showed that the sediments of those areas are moderately polluted with Co, Ni, and Zn metals. The degree of contamination (Cdeg) for the sediments of the study area in general ranges from low - medium pollution, the pollution load index (PLI) average of (1.03) showed that the sediments of the study area were contaminated with heavy metals. Therefore, we conclude that the environment of the Tigris River is polluted with heavy metals, but it is not at the level that causes concern at present.

Benin’s waterways are affected by several forms of pollution that are linked in particular to anthropic activities. This study aims to detect the presence of antibiotic residues, the frequency of antibiotic resistant bacteria and the levels of heavy metals in Benin’s waterways. 160 surface water samples from streams in Benin were collected. They were filtered by the membrane filtration method, then incubated on different media. The isolated bacterial species were identified by API 20E gallery and specific biochemical tests. After detection of the resistance profile of the latter, the antibiotic residues were quantified in the samples by the ELISA technique on plate and the physicochemical analyses were performed by Multi 3630 IDS SET KS2 multimeter. Finally, heavy metal levels were detected by the MERCK test kit method specific to each metal. The bacterial species mostly identified were Klebsiella pneumoniae (56.59%), Klebsiella spp. (18.68%), Enterobacter spp. (12.63%). The most abundant resistance of bacterial strains was to amoxicillin + clavulanic acid (92%), followed by metronidazole (86%). Metronidazole was the antibiotic with the highest residue concentration in the samples (6.578 to 6.829 µg/L), followed by ciprofloxacin (2.142 to 9.299 µg/L). Benin streams contain heavy metals such as mercury (0.454±0.129 µg/L), lead (0.040±0.50 mg/L), zinc (6.120±16.017 mg/L), nickel (0.155±0.233 mg/L) and cadmium (0.154±0.132 mg/L). The analysis of the physico-chemical parameters showed that, apart from electrical conductivity, all parameters comply with Beninese and World Health Organization standards. Actions must be taken to clean up these rivers to preserve the integrity of aquatic ecosystems in Benin.

BTEX is one of the common compounds in the breathing air of gas station workers, which can cause high carcinogenic and health risks. The present study was conducted to assess the carcinogenic and health risks of occupational exposure to BTEX compounds in gasoline fuel distribution stations in Karaj. This descriptive and cross-sectional study was conducted to assess the carcinogenic and health risks caused by exposure to BTEX compounds in 2021 during the summer and winter in six fuel distribution stations in Karaj. Occupational exposure to BTEX was measured according to the NIOSH 1501 method. Cancer and non-cancer risk assessment were performed according to the United States Environmental Protection Agency (USEPA) method. Data were analyzed in SPSS software version 26. The average occupational exposure to benzene, toluene, ethyl benzene, and xylene during a work shift among all participants in summer and winter were 83.33 - 89.33, 202 - 210.66, 126.55 - 136.83, and 168.81 - 174.83 µg.m-3, respectively. The highest concentration of BTEX compounds was observed in Gas station in the center of the city. The mean carcinogenic risk value of benzene and ethylbenzene were 139×10-2 and 27×10-2, respectively. The highest carcinogenic risk value due to exposure to benzene and ethyl benzene was observed in Gas station in the center of the city. The mean non-carcinogenic and health risks of occupational exposure to benzene, toluene, ethyl benzene, and xylene were 173.79, 14.19, 3.61, and 12.87, respectively.  The findings demonstrated the values of carcinogenic and non-carcinogenic risk in the majority of participants were within the definitive and unacceptable risk levels. Therefore, corrective measures are necessary to protect the employees from the non-cancer and cancer risks.

Using ethanol in gasoline is considered one of the most significant goals in the 2030 agenda, which has been set a 15-year plan in order to achieve it since 2015. Appropriately, this project was planned for predicting the value of the most important engine parameters such as the equivalence air-fuel ratio (φ), fuel consumption (ṁf), and brake thermal efficiency nb. th, and brake-specific fuel consumption (BSFC) by regression models. According to the protocol of this project, first, the determined percentages of ethanol were added (0, 20, 40, 60, and 80%) to gasoline at different engine speeds (850, 1000, 2000, 3000, and 4000 rpm and the New European Driving Cycle test). After testing, calculating, mathematical programming, and fitting the regression models for the two SI-engine (TU5 and EF7) with different properties of engine design,12 regression equations have been determined for each of the ‘ (positive linear model), (ṁf) (negative linear model), nb.th (negative second-order polynomial model), and BSFC (positive second-order polynomial model), respectively. Clearly, these 48 regression equations with different line slopes will be able to predict the exact value of the ‘, (ṁf), nb.th, and BSFC for each concentration of ethanol at different engine speeds in order to help automotive industries for trend predicting them in other similar engines.

Persistent pollution of surface waters by hydrocarbon compounds is one of the foremost threats to limited global freshwater resources. This study analyzed the abundance, diversity and degradative capacities of hydrocarbon-utilizing bacteria in chronically polluted Kono River in the Nigerian Niger Delta in order to establish the bacterial drivers of ecological regeneration of the river after an oil spill. The study further aimed to develop a specialized bacterial consortium for application in bioremediation interventions. Bacillus, Pseudomonas and Enterobacter spp. were predominant out of the 82 isolates obtained. Klebsiella pneumoniae and two species of Enterobacter cloacae were identified as the most efficient hydrocarbon utilizers. The isolates were also confirmed as biosurfactant producers and possessed the alkB1 and nahAc genes for degradation of aliphatics and aromatics. E. cloacae-K11, K. pneumoniae-K05, E. cloacae-K12 and their consortium were able to degrade the total petroleum hydrocarbons and polycyclic aromatic hydrocarbons in batch systems by 59.37% – 96.06% and 68.40% – 92.46% respectively. K. pneumoniae-K05 showed the greatest petroleum degradation capacity of the three isolates but hydrocarbon degradation was most efficient with the bacterial consortium. The results obtained showed no significant differences at p≤0.05 between the degradation capacities of K. pneumoniae-K05 and the consortium for PAHs but a significant difference (p≤0.05) was seen with TPH degradation. A viable hydrocarbon degrading bacterial consortium was developed at the end of the study and it was concluded that the polluted river water displayed inherent potential for effective natural attenuation.

Four regions of the Farahzad River Valley with different topography were selected to fully survey it and study the effects of morphology on local climate. then one of the hot days of the month of June 2021 (June 6th) was selected because the wind speeds increase in spring. According to the comparison of the simulation results with the existing site plans, the temperature in area 3 was the highest, 39.60 degrees, and the wind speed was 3.57 m/s. On the other hand, the study and analysis of the maps showed that the temperature of the roads in regions 3 and 4 were higher than the other two regions with a temperature range of 37.69-38.40, so the presence of impervious asphalt surfaces on the roads is very effective in increasing the air temperature in these areas.  Comparisons also showed that tall buildings and vegetation create shaded areas and increase wind speed. Based on this, two scenarios were designed. In the first scenario, doubling the height of buildings increased wind speed in Region 3 by 3.42 m/s and decreased temperatures by 1.59 degrees. In the second scenario, when tall trees were planted at certain distances around the streets, the temperature in Region 3 decreased by 1.68 degrees and the wind speed increased by 1.68 m/s. The results show that the differences in the topography of urban valleys cause ventilation of the environment and that the effect of this feature in other environments is more effective through planting than through buildings.

The applicability of Polyetheretherketone/Polyvinylalcohol Nanocomposite Modified with Zinc Oxide Nanoparticles synthesized for eliminating humic acid rapidly from industrial wastewater. Identical techniques, including BET, FTIR, XRD, and SEM have been utilized to characterize this novel material. Also, the impacts of variables including initial humic acids (HAs) concentration (X1), pH (X2), adsorbent dosage (X3), and sonication time (X4) came under scrutiny using central composite design (CCD) under response surface methodology (RSM). The values of 10 mgL-1, 6.0, 0.025 g, and 5.0 min were investigated through batch experiments, considered as the ideal values for humic acids (HAs) concentration, pH, adsorbent dosage, and contact time, respectively. Adsorption equilibrium and kinetic data were fitted with the Langmuir monolayer isotherm model and pseudo-second-order kinetics (R2: 0.999) with maximum adsorption capacity (102.0 mgg-1), respectively.  The overall results confirmed that Polyetheretherketone/Polyvinylalcohol Nanocomposite Modified with Zinc Oxide Nanoparticles could be a promising adsorbent material for humic acids (HAs) removal from industrial wastewater.

cadmium usually enter the environment and water resources through wastewater, released by various industries, and may have adverse effects. The current study employs surface of bentonite clay available locally in order to remove cadmium In solutions contaminated with this type of ions, in order to research on a surface with a high ability to adsorption of cadmium (II) ions, study Some factors affect the adsorption process on bentonite clay, such as contact time, pH the solution, Adsorbent particle size, Initial concentration of solutions and temperature of the solution were examined in the a batch process mode. The amount of adsorbed Cd (II) increased with height temperature, the optimum adsorption pH was about 6.5. Under this condition, the percent removal was 95.17%. The adsorption  isotherms were studied and  the results of adsorption processes were more fitted with Friendlich model rather than Langmuir adsorption model. Thermodynamic study showed that,  ΔH was endothermic, ΔG is found to be negative That is, the process is automatic and  ΔS was found to be positive. The current study also involves  practical application using bentonite to get rid of Cd(II) ions  to  from wastewater of Hamdan's station of the Basra- iraq, The results indicate high affinity (97.84%) removal of Cd(II) ions.

Radiology and photography films are mainly made of silver halides, which are very sensitive to light. The developer-fixing solution reduces silver salt crystals and turns them into black metallic silver on film and a stable and clear image appears on the film. After several uses of the fixing solution, its efficiency is reduced due to the decrease in the concentration of sodium thiosulfate and finally, it cannot be used since there is not enough awareness regarding its harm, so it enters the environment through wastewater. In this study, the recovery of fixing solution waste has been investigated. The recovery of the solution waste, silver extraction, and direct synthesis of nanoparticles have been performed by chemical reduction method from the waste. The obtained samples were analyzed and studied by EDX, XRD, and SEM techniques. The results showed that the fixing solution waste and silver metal were recovered properly with a purity of 99.81%. Also, AgNPs were synthesized by chemical reduction. Recovery of the fixing solution waste -for the first time- and metallic silver, as well as the synthesis of AgNPs by chemical reduction method, is an economical method and free of any contamination.