A new traiazole derivative (4-amino-5-(((5-methyl-1H-benzo[d]imidazol-2-yl)thio)methyl)-2,4-dihydro-3H-1,2,4-triazole-3-thiol, (L), was employed as a chelating ligand to form a dibutyltin chloride complex and improve the poly(vinyl chloride) (PVC) properties. The doped PVC films were characterized via FT-IR, UV-Vis spectrum, elemental analyses (C, H, N, and M (metallic)), and magnetic susceptibility and conductivity measurements. These characterizations were conducted at room temperature, and it was disclosed that the chelating ligand rules as a bidentate chelate. The photostabilization examination of plain and L-doped PVC films was conducted in the presence of ambient air using the accelerating weather tester, where the doping ratio was fixed to 0.5 wt.%. The photostabilization performance of the additive was evaluated by tracking the indexes of carbonyl (ICO), polyene (IPO), and hydroxyl (IOH), and weight loss relationship with irradiation time. It was noticed that the values of ICO, Ipo, and IOH enhanced with the irradiation time, where this improvement relied on the presence of the Bu2SnL complex.

This study was conducted in order to assess the level of heavy metals in the water, soil, and tissues of Pomacea canaliculata from Lake Dakong Napo, Esperanza, Philippines as well as identify the histopathological alterations in the gonads and muscles of the snail. Heavy metals were detected using Atomic Absorption Spectrometry and slides for histological studies were prepared using histological routine procedure. Results revealed that in sediments Cr (174.67±62 mg/L) and Ni (269.33±17.56 mg/L) were above from the recommended safe limits of the international standards, US EPA (≤25) and FAO (≤50) while concentrations of Pb (16.35± 0.58 mg/L), Cd (5±1.42 mg/L), and Cr (1±0 mg/L) in water were above from the recommended safe limits of the national standards, DAO (≤0.05; ≤0.01; ≤0.05). These heavy metals were below the permissible limits in the gonads and muscles of P. canaliculata however, alterations in the tissues of the snail are evident suggesting that these heavy metals and other environmental stressors are negatively affecting the organisms inhabiting the lake.

Microplastics pollution has become a matter of global concern because of its effects on aquatic life and the ecosystem. This study investigated the abundance and types of microplastics found in an urban canal of Thailand. Water quality and the relationship between microplastics pollutants and the physicochemical properties of water quality were also analyzed to provide evidence for this study. The mean abundance of microplastics was 370 ± 140 particle(p)/m3. The highest number and concentration of microplastics were found on surface water corelated with urbanization. Transparent brown and transparent colors in the form of film and fiber/lines were the predominant morphology. Polypropylene (PP) and polyethylene (PE) were the most abundant polymer type in all surface water samples. Furthermore, water quality was related with microplastic pollution. The physicochemical properties of turbidity (0.99), conductivity (0.97), total solid (0.95) and biological oxygen demand (0.84) were accounted for greatest influences on microplastics distribution. The estimated equation of microplastics was also closely corelated with water quality. These results demonstrate that microplastic pollution has progressed more in poor water quality than good water quality, indicating that the inflow process and sources of microplastics are similar to those of other pollutants. Therefore, this study is expected to encourage and enforce solid waste and wastewater management policies that prevent microplastics pollution in the environment.

In developing countries, wastewater treatment is confined to secondary systems. Hence even after treatment, wastewater effluent has a high level of nutrients which causes eutrophication and has destructive impacts on receiving bodies. Literature reveals that phycoremediation can be the best solution to address the problem faced but is time-consuming, ranging from days to weeks. Hence, the present study aimed to determine an optimum detention time for the microalgal system to treat domestic wastewater. The retention time for treatment in the study was divided into an aeration and settling periods. During the study, aeration time varied from 2 hours to 24 hours, followed by 1-hour settling period for each aeration time. Optimum detention time for microalgal treatment was obtained at 11 hours of detention time (10 hours aeration and 1-hour settling). Parameters analyzed during the study were pH, EC, TS, TSS, TDS, nitrate, phosphate, ammonia, COD and DO. However, the main focus was on nutrients (phosphate and ammonia) and organics (COD) removal while determining the optimum detention time. Maximum removal efficiency obtained for COD, ammonia and phosphate for non-filtered effluent was 75.61%, 90.63% and 83.29%, respectively. However, removal efficiency further increased for filtered effluents to 86.34%, 100% and 91.12% for COD, ammonia and phosphate, respectively. Algal treatment offers an ecologically safe and more affordable system for nutrient removal and eliminates the need for tertiary treatment.

The time series model has been exploited to estimate the relationship between meteorological variables and air in Mashhad with respiratory mortality. For this purpose, data on respiratory mortality was based on data recorded on March 2014 to 2015. In order to investigate the effect of meteorological variables and air pollution values on respiratory mortality, the Box- Jenkins time series model has been utilized. Moreover, the effect of age and seasons on the number of respiratory deaths was assessed by the linear regression and ANOVA test. The fit of the final model to determining the monthly relationship between meteorological variables and air pollutants with the number of respiratory mortalities is a (1,0,2) ARIMA. In the monthly survey, temperature and rainfall have the inverse relationship and pressure has the direct relationship with the average of 7.4, 3.2, and 17.42 on the respiratory mortality. It was also found direct relationship between the mortality from respiratory diseases and CO and O3 and inverse relationship with SO2, NO2 and PM2.5 pollutants with an average of 67.40, 17.42, 17.89, 6.83, and 0.68, respectively. Also, the results of this study indicate that older people are more likely to be affected by the inappropriate status of air quality by 0.37%. The results showed a significant difference between respiratory mortality in different seasons of the year, and the highest number of deaths occurred in the winter.

Severodvinsk city is the largest industrial center for the construction and repair of naval vessels in the NW Russia. The purpose of the presented study was to identify the main sources of pollution of the Severodvinsk industrial region and assess the ecological situation based on analysis of toxic metals in water and snow. Heavy metals content in water, melt snow filtrate and solid residue was measured using ICP-MS. On the urban area, there were high concentrations of Fe (up to 2843 MPC) in soluble form of snow, Al (up to 4680 MPC), Fe (up to 2807 MPC), Ni (up to 66.5 MPC), Pb (up to 44.7 MPC), Cd (up to 43.3 MPC), Cr (up to 43.2 MPC), Mn (up to 13.3 MPC), Co (up to 7.3 MPC), and As (up to 3.4 MPC) in insoluble form of snow, Fe (up to 56213 MPC) in water from wells. There were high values of mineralization (598 mg/L) and low pH values (to 5.21) in sites most susceptible to anthropogenic pollution. Statistical analysis showed that most of the metals in snow cover were linked with each other by strong correlation (r>0.9). Calculation of toxicological indices HMEI, HMPI, HMTL, HI and CR showed extremely high and dangerous for public health level of heavy metal pollution in the Severodvinsk industrial district. Studied radiation parameters of water from wells were within acceptable limits. Results obtained indicate the need to change the type of fuel in thermal power plant and reduce toxic emissions from the shipbuilding enterprises.

Microplastics are widely used to manufacture diverse products such as textiles, skin care products, and household products such as detergents and soaps. However, microplastic pollution and its potential health risks are raising concerns worldwide. This study characterized and determined the safety of microplastics in water and sediments obtained from three locations, namely Ibeshe, Amuwo Odofin, and Ojo along Badagry lagoon, Lagos, Nigeria. The samples of the lagoon's surface water and sediments were treated and analyzed for the abundance of microplastics, as well as their shapes, sizes, and types of polymers. The risk index of the polymers in the microplastics was also estimated. Microplastics were found to be more abundant (p ≤ 0.05) in the sediments (283–315 particles/kg) than in the surface water (108–199 particles/L). In both the water and sediments at all the locations, the dominant shapes were fibers (52%–90%), followed by fragments (3%–32%) and films (1%–25%). In order of significance, the microplastic size range of 0-100µm and 100-500µm dominated the surface water, while the size range of 1000-5000µm and 500-1000µm dominated the sediments at all the locations. The dominant polymers in both the water and sediments at all the locations were polyethylene, polypropylene, and polyamide, while the least was polystyrene. In both the water and sediments at all the locations, the dominant risk score among the polymers is III (moderate risk). The results obtained suggest that microplastic pollution poses environmental and health risks to the lagoon, aquatic organisms, and humans. As such, the lagoon required microplastic remediation and control.

This study aimed at quantifying the heavy metal levels in soils and vegetables sampled from five suburban regions of Nairobi, Kenya. Using inductively coupled plasma- mass spectrometry (ICP-MS) the metals were quantified from the samples. The assayed heavy metals including Cd, Cr, Co. Cu, Fe, Hg, Mn, Ni, Pb, Zn and the metalloid arsenic were elevated beyond the reference values in both soils and vegetables. High pollutant levels in soils were affiliated to use of industrial and domestic wastewater for irrigation, application of heavy metal containing agrochemicals and geogenic sources of the pollutants. In collard leaves, the uptake of contaminated water via the roots and subsequent accumulation in the leaves was attributable to the observed results. The total hazard quotient (THQ) and hazard index (HI) as a result of arsenic and Hg was >1 in all sampled sites and >10, respectively for both indices and heavy metals. Similarly, the cancer risk (CR) and target cancer risk (TCR) from consumption of collard was greater than the recommended levels of 10-6 and 10-4, respectively with exception of Pb. The indices were indicative of negative non-carcinogenic and carcinogenic effects of consuming the vegetables to the community of the study area. The results of the study, though preliminary, suggest the need to safeguard the health of communities in the study area to ensure that they do not consume heavy metal contaminated vegetables due to the established health effects of such pollutants.

This research aims at developing a new relation to estimate the urban runoffwater quality through urban land use. According to the first phase of this research, sixurban characteristics and land use indices have been defined concerning all parameterswith either direct or indirect impacts on urban water quality: Population, land use type,meteorological factors, local physiographical parameters, urban patterns etc. have beenconsidered when developing the new indices. Three study areas, including different urbanland uses, have been selected in Tehran Metropolitan and urban drains maps andstructures have gone under study to determine the sampling points. Multi-statisticalanalysis, discriminate analysis, and multi-linear regression analysis have been applied forall water quality results and urban indices in each site, with the results revealing verystrong relations between urban land use and water quality variation. Temporarypopulation especially in downtown site has proved to be an effective temporal factor onhow even public transport could not have any significant effects, in case populationdensity has no significant influence on water quality, as all sanitary waste water inselected sites is collected through urban wastewater systems separately. General slop is asignificant factor in hydrocarbons and heavy metals, once they are not alongside thestreets route. All told, this paper recommends reusing urban drained runoff locally beforejoining other regions’ collectors. Here in urban drainage system, collection andaggregation of water could not be an appropriate factor in water quality managementunlike river systems. The model could be employed in urban local water consumptionmanagement in irrigation and public recovery.

In the present investigation, coagulation-flocculation and fenton process in conjunction with phytoremediation by water hyacinth (Eicchornia crassipes) were applied to treat the most frequently occurred contaminants in textile wastewater. The mean values of EC, TDS, turbidity, pH, DO, BOD, COD and TOC in the raw effluents were 2300 μSCm-1, 1260 mgL-1, 48.28 FTU, 10.5, 1.2 mgL-1, 265 mgL-1, 522 mgL-1 and 12.8 mgL-1, respectively whereas the average concentration of Cr, Pb, Mg, Cu, Ni and Zn was 0.86, 1.21, 10.97, 0.47, 2.85 and 0.52 mg/L, correspondingly which evidently indicated that the effluents were highly contaminated compared to Bangladeshi standard. The results demonstrated that the values of EC, TDS, turbidity, pH, BOD, COD and TOC reduced significantly compared to raw effluents by both coagulation-flocculation and fenton processes and meet the standards set by BDS-ECR except BOD and DO. After being treated the COD value reduced to 70 mg/L (86.56%) and 188 mg/L (63.985%) from its initial concentration by coagulation-flocculation and fenton process, respectively on the other hand TOC removal efficiency by coagulation- flocculation process was 97.8125%, significantly greater than fenton methods where removal efficiency was 63.9%. However, the BOD removal efficiency by both treatment processes was ~50% which was not satisfactory compared to local standard. Interestingly, the concentration of DO increased substantially by both coagulation-flocculation (1.2 to 4.4 mg/L) and fenton process (1.2 to 3.85 mg/L). In case of trace elements removal, the combination of coagulation-flocculation-water hyacinth and fenton-water hyacinth show promising results where the removal efficiency of coagulation-flocculation-water hyacinth and fenton-water hyacinth was 24%-76% and 17%-76.36%, respectively. Therefore, it can be concluded that coagulation-flocculation-water hyacinth combination is better than fenton-water hyacinth combination in terms of trace metals removal. Textile effluents treatment and management is considered as one of the most significant issues in Bangladesh herein based on the this study, combination of chemical and phytoremediation technologies could be a promising sustainable low cost alternative for Bangladesh’s textile industrial sector.