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Wastewater-based epidemiology (WBE) with advantages like complementary, cost-effective, comprehensive, and rapid tool is used for measuring and monitoring of illicit drugs in the population. Smoking cigarettes and tobacco use are common habits in nowadays community. This systematic review and meta-analysis are the first study to calculate the consumption amount of nicotine (NIC) by searching in WBE studies on a global scale. The related studies were retrieved within the international databases including Scopus and web of science up to February 2021 and 21 articles containing 87 measurements covering 275.3 million people with a total wastewater samples of 2250 were included. ​Results show that the maximum and minimum nicotine consumption rate (mg/1000 inh./day) was in Portugal (5860) and Viet Nam (1201), respectively. The global pooled amount of nicotine consumption rate was 2476 mg/1000 inh./day (95% CI (2289–2663). Risk assessment of nicotine consumption rate through WBE was calculated by the margin of exposure (MOE) approach. The MOE amounts were obtained by probabilistic Monte Carlo simulations for daily nicotine consumption. In total, 82% of nicotine consumption measurements located in the "risk" level (MOE

The magnetic nanocomposites composed of copper sulphide, iron oxide, and graphene oxide (CuS/Fe3O4/GO) were synthesized through a facile sol-gel combined with hydrothermal techniques for photodegradation of methylene blue (MB) as a model organic pollutant. The as-prepared samples were characterized by powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), differential reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray analysis (EDX) and results confirmed successful synthesis of magnetic nanocomposite. Presence of Fe3O4 and GO in nanocomposite induced a synergistic effect in CuS performance as CS88F6G6 (i.e. 88% CuS, 6% Fe3O4, and 6% GO). The photocatalytic degradation efficiency of MB reached up to 90.3% after exposure to visible light irradiation for 80 min. The composite nanosheets are photostable, reusable, and magnetically recoverable, revealing potential application in removal of organic pollutants.

Finding a facile and practical method to produce black TiO2 remains a challenge. Bismuth-vanadium co-doped black TiO2 (BVBT) was synthesized as a visible light driven photocatalyst by a simple one-pot hydrothermal method. The synthesized BVBT was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV-vis diffuse reflectance spectroscopy (UV-Vis DRS). The light absorption of the synthesized Bi-V co-coped black TiO2 nanoparticles was significantly improved in the visible and infrared regions. The XRD patterns indicated that the black TiO2 contained mixed phases of brookite, anatase, and rutile of TiO2. This was further confirmed by Raman spectroscopy. The photocatalytic activity of the sample was evaluated by reduction of hexavalent chromium (Cr(VI)) under visible light irradiation. Among investigated hole (h+) scavengers, ethylenediaminetetraacetic acid (EDTA) led to the highest reduction of Cr(VI) with a molar ratio of 1:5 (EDTA:Cr(VI)). The results indicated that the Bi-V co-coped black TiO2 nanocomposite can reduce 94% of 1 mg/L of Cr(VI) within 20 min irradiation time (pH 3 and catalyst dose of 1 g/L). Introducing a simple method to synthesize black TiO2 which has absorption in the visible and infrared region can open up new applications.

Wastewater-based epidemiology (WBE) is a complementary, well-established comprehensive, cost-effective, and rapid technique for monitoring of illicit drugs used in a general population. This systematic review and meta-analysis is the first to estimate the rank and consumption rate of illicit drugs through WBE studies. In the current study, the related investigations regarding the illicit drug consumption rate based on WBE were searched among the international databases including Scopus, PubMed, Science direct, Google scholar, and local database, Magiran from 2012 up to May 2019. The illicit drug consumption rate with 95% confidence intervals was pooled between studies by using random effect model. The heterogeneity was determined using I2 statistics. Also, subgroup analyses were conducted to examine the possible effects of year and location of studies on observed heterogeneity. Meta-analysis of 37 articles indicates that the overall rank order of illicit drugs according to their pooled consumption rate can be summarized as tetrahydrocannabinol or cannabis (7417.9 mg/day/1000 people) > cocaine (655.7 mg/day/1000 people) > morphine (384.9 mg/day/1000 people) > methamphetamine (296.2 mg/day/1000 people) > codeine (222.7 mg/day/1000 people) > methadone (200.2 mg/day/1000 people) > 3,4-methylenedioxymethamphetamine (126.3 mg/day/1000 people) > amphetamine (118.2 mg/day/1000 people) > 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (33.7 mg/day/1000 people). The pooled level rate was 190.16 mg/day/1000 people for benzoylecgonine (main urinary cocaine metabolite), 137.9 mg/day/1000 people for 11-nor-9-carboxy-delta9-tetrahydrocannabinol (main metabolite of cannabis), and 33.7 mg/day/1000 people for 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (main metabolite of methadone). The I2 values for all selected drugs were 100% (P value

The presence of excess nitrate in groundwater limits it use as a drinking water supply and its removal is critical to balance the nitrogen cycle in aquatic systems. In this study, ultra-thin 2-dimensional Ag-TiO2/γ-Al2O3/Chitosan (Ag-TiO2/Al2O3/CS) nano-composite was synthesized for the fast reduction of nitrate under UVA irradiation from aqueous solutions. As-synthesized nano-composite was well characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption isotherms, Fourier-transform infrared spectroscopy and UV–vis diffuse reflectance spectroscopy. Experimental variables including pH, nitrate concentration, photocatalyst dose and contact time were considered to demonstrate their effect on the rate of nitrate reduction. Formic acid was used as a radical scavenger at optimal concentration of 2:1 (formic acid:nitrate). The results showed that upon UVA irradiation, the synthesized nano-composite exhibited fast nitrate reduction in broad pH range (about 74% removal at pH 11 in 5 min reaction time) in diverse water chemical conditions. The Ag-doped and hybrid heterostructures can effectively utilize UV–visible-light to remove nitrate and degrade formic acid. For the 3 cycles the photocatalyst efficiency remained same and after the third cycle, its efficacy decreased gradually. This work suggests 2D Ag-TiO2/Al2O3/CS nano-composite for the fast removal of nitrate in drinking water treatment.

The consumption of marine foods such as Tilapia spp fish offers several beneficial nutrition effects, however, it can endanger the health of humans while contains a high concentration of potentially toxic elements (PTEs). In this work, the related studies regarding the concentration of PTEs in Tilapia fish were collected by searching among some databases such as the Web of Science, Scopus, PubMed, and Embase. Furthermore, the concentration of PTEs in Tilapia spp fish was meta-analyzed by the aid of the random effect model (REM). Additionally, the non-carcinogenic risk in both adults and children due to the ingestion of PTEs via consumption of Tilapia spp fish was estimated by calculating target hazard quotient (THQ) and total target hazard quotient (TTHQ). Meta-analysis of 79 articles (87 data) showed that rank order of PTEs (mg/kg) in Tilapia spp fish was Fe (9.925)>Zn (1.556)>Mn (1.065)>Cr (0.627)>Cu (0.485)>Pb (0.218)>Ni (0.217)>As (0.140)>Hg (0.113)>Cd (0.107). The rank order of PTEs based on their quota in TTHQ was As (86.21%)>Hg (4.01%)>Ni (2.96%)>Pb (2.32%)>Zn (1.38%)>Fe (1.21%)>Cu (0.95%)>Cd (0.80%)>Cr (0.10%)>Mn (0.06%). Also, the non-carcinogenic risk assessment shows that TTHQ for both adults and children consumers was lower than 1, demonstrating no considerable non-carcinogenic risk in all countries.HighlightsMeta-analysis of data from of 79 articles (87 data-reports) was conducted.The order of PTEs was Fe > Zn > Mn > Cr > Cu » Ni > As > Hg > Cd.Quota of As (86.21%) in TTHQ was higher than others PTEs.Consumers are not at the considerable non-carcinogenic risk in all countries. Meta-analysis of data from of 79 articles (87 data-reports) was conducted. The order of PTEs was Fe > Zn > Mn > Cr > Cu » Ni > As > Hg > Cd. Quota of As (86.21%) in TTHQ was higher than others PTEs. Consumers are not at the considerable non-carcinogenic risk in all countries.

Background: However, the consumption of honey offers several beneficial advantages; it can be sources of some contaminants, such as potentially toxic elements (PTEs). Scope and approach: In the current study, the related investigations regarding the concentration of PTEs in honey a global scale among the international databases including Scopus, PubMed, ISI Web of Science and Embase were collected and analyzed. Also, the health risk assessment in the children and adults due to ingestion of PTEs via consumption honey was estimated by calculating hazard quotient (HQ) and total hazard quotient (THQ) and cancer risk (CR). Key findings and conclusions: Meta-analysis of 33 articles with 45 studies indicates that the overall rank order of PTEs according to their pooled concentration PTEs can be summarized as Fe (5.657 mg-kg-DW) > Mn (3.430 mg-kg-DW) > Pb (0.555 mg-kg-DW) > Cr (0.496 mg-kg-DW) > Cu (0.330 mg-kg-DW) > Ni (0.312 mg-kg-DW) > Cd (0.049 mg-kg-DW) > As (0.026 mg-kg-DW) > Hg (0.002 mg-kg-DW). The rank order of PTEs according to HQ was defined as Pb > Cd > Mn > Fe > Ni > As > Cu > Hg > Cr. Moreover, the lowest and highest values of HQ were observed in Macedonia and Turkey, respectively. The corresponded values of HQ and THQ in all countries investigated was lower than 1 value. Therefore, consumers are not at non-carcinogenic risk. Also, CR inorganic of As in the consumers in all countries investigated was lower than

A novel application of maghemite nanoparticles embedded activated carbon (γ-Fe2O3@AC), as a mesoporous heterojunction composite, coupled with UV light was used for enhanced activation of peroxymonosulfate (PMS) for degradation of cyfluthrin insecticide. The performance of γ-Fe2O3@AC/UV/PMS system was assessed as affected by different concentrations of PMS, catalyst and pollutant, pH of aqueous media, reaction time, co-exiting water matrix components and trapping agents. A tentative mechanism was proposed for the PMS decomposition and reactive species production in both solid and liquid phases. Catalytic activity of γ-Fe2O3@AC in the PMS decomposition was enhanced significantly when it coupled with UV light. In optimal conditions (pH 4.0, PMS 4.0 mM, 0.4 g/L catalyst, C0 = 60 mg/L and time 80 min), the efficiency rates of 88.5 and 52.4% were achieved for degradation and mineralization of cyfluthrin, respectively. The degradation rate affected by matrix anions was reduced in order of HCO3− > NO3− > Cl− > SO42−. Cycling tests displayed the negligible iron leaching and high recyclability for γ-Fe2O3@AC within 5 times use. A strong synergistic effect was observed between applied techniquess in the activation of PMS. Pseudo-first-order kinetic model represented a significant correlation with the experimental data of degradation process. Among detected free radicals, SO4•− species had a conquer role in catalytic oxidative degradation process. γ-Fe2O3@AC/UV/PMS system showed an excellent performance in treatment of simulated real water and wastewater samples. Generally, coupling of γ-Fe2O3@AC and UV for improving PMS activation can be introduced as a successful and efficient approach to catalytic degradation of organic matters owing to tremendous catalytic activity, easy recovery, high stability and reusability potential and the generation of various reactive free species simultaneously.

N, S-doped TiO2 (NST), N, S-doped ZnO (NSZ) and their composite with chitosan (NST/CS, NSZ/CS) were synthesized by sol gel-hydrothermal method. The prepared samples were characterized using XRD, FTIR, TEM and BET techniques. These photocatalysts were used for the photocatalytic degradation of tetracycline under visible light irradiation. At screening test, NST/CS had the highest tetracycline degradation efficiency of 91% for duration of 20 min under visible light. The blending of chitosan with NST increases the rate of photocatalytic degradation of tetracycline about 2 times. A detail characterization including HRTEM, SEM, EDS and DRS were conducted for NST/CS, the most active photocatalyst in this study. Photocatalytic activity test was conducted by varying tetracycline concentration, irradiation time, catalyst's concentration and pH using response surface methodology to find out the optimum condition for photocatalytic activity. The reusability of as-synthesized NST/CS was assessed which due to its high recoverability can be applied as an effective catalyst for degradation of organic substances in water and wastewater especially for degradation of emerging pollutants such pharmaceutical pollutants. The results from this work show a promising material for local authorities and pharmaceutical facilities to use for the treatment of pharmaceutical pollutants and tetracycline removal in water resource.

This study was conducted to investigate the residues of pyrethroid and organophosphorus pesticide in flour and breads which were collected from local markets in Kermanshah province, Iran. Four diff...

The magnetic nanocomposites composed of copper sulphide, iron oxide, and graphene oxide (CuS/Fe

Finding a facile and practical method to produce black TiO

The sol-gel dip-coating method is a simple method to synthesize TiO2 thin film, using titanium butoxide and hydrogen peroxide. In this study in addition to TiO2 thin film, the photocatalytic activity of its intermediate products, titanium peroxide gel and ambient dried titanium peroxide film, was also evaluated. The titanium peroxide gel was used directly after gelation, ambient dried titanium peroxide film coated on glass rings was used without thermal treatment and anatase TiO2 thin film was used after thermal treatment at 500oC. These photocatalysts were characterized by different characterization techniques and their adsorption and photocatalytic activity were evaluated by using methylene blue as a model pollutant. All three photocatalysts adsorbed the selected dye model and degraded it in the presence of sunlight but with different removal rate. It was found that the gel had the highest removal rate followed by ambient dried titanium peroxide film and TiO2 thin film. However, this sequence was vice versa in the case of photocatalyst life span when the photocatalysts were reused. The photocatalytic study showed that all three photocatalysts are very effective for 100% degradation of methylene blue within 5-60 minutes under sunlight irradiation. This can be a breakthrough of using titanate based photocatalyst for the cost-effective adsorption and photocatalytic degradation of pollutants based on the climate and availability of sunlight. The energy cost analysis was performed for the catalyst based on electrical power consumption. The calculated power cost for synthesizing TiO2 thin film was approximately 0.9 $/kWh. However, the energy required for the synthesis of two other catalysts was zero, means there is no money needed to be spent on electricity.

In this study, highly visible-light photoactive nitrogen and sulfur co-doped TiO2 nanoparticles and nanosheets were synthesized via sol-gel and hydrothermal methods, respectively. The photocatalytic activity of N,S-TiO2 photocatalysts were evaluated and compared by degradation of non-steroidal anti-inflammatory drugs, ibuprofen(IBP) and naproxen (NPX), under simulated solar light. The sol-gel method developed a mesoporous structure N,S-TiO2 nanoparticle which contains both anatase and rutile phases with large BET surface area (132 m2/g). N,S-TiO2 nanosheets with pure anatase phase, with larger mesoporous structure and a smaller BET surface area (64 m2/g) was formed via hydrothermal method. NS-TiO2 nanoparticles were coated on UVC-treated polycarbonate (PC) (NS-TiO2@PC) by simple deposition method. The results showed that under identical condition, N,S-TiO2 nanoparticles can degrade 85% and 99.3% of ibuprofen and naproxen while 71.6% of IBP and 99.1% of NPX were degraded by N,S-TiO2 nanosheets. Optimization results showed that maximum degradation efficiency was achieved at the optimum conditions: irradiation intensity 8.36 mW/cm2 (for ibuprofen) and 10 mW/cm2 (for naproxen), initial drugs concentration 10 mg/L and reaction time 121 min. Under this condition, the maximum degradation efficiency of 83% and 100% were achieved for ibuprofen and naproxen, respectively. The results of this study elucidate co-doped NS-TiO2 nanoparticles prepared by sol-gel methods are photocatalytically more effective and practically easier to reproduce for the practical application, both in terms of energy saving and cost reduction. The energy cost analysis indicated that sol-gel method for synthesis of N,S-TiO2 is more cost effective.

Today, the use of bottled water has increased significantly for various reasons, such as the low quality of tap water, presence of hazardous chemicals in piped water, ease of transport, and accessibility. Therefore, considering the quality features of bottled water is of utmost importance. The present study was conducted in the two stages of questionnaire and laboratory with the aim of determining the correlation between the quality of hardness when bottled water is purchased and evaluate the calcium and magnesium contents in the laboratory. The applied questionnaire was designed based on water hardness in four sections of knowledge and attitude, and its validity and reliability were confirmed. The calcium and magnesium contents were determined using standard methods and the inductively coupled plasma mass spectrometry apparatus. The obtained results indicated that the most important indicators of purchasing bottled water were softness availability, brand, and coldness. Contrary to consumer claims, the most commonly used bottled water (60% of the brands) were observed to be those with high hardness. Therefore, it could be concluded that factors such as availability, marketing, and percentage of the consumption market are the most important influential factors in the consumption rate of bottled water.

Polycyclic aromatic hydrocarbons (PAHs) are a group of pollutants which occur in considerable amounts in the environment and food. In this study, a meta-analysis study was conducted on PAHs concent...

Photocatalysis, a green technique is widely applied in the fields of environmental remediation for the removal of many pollutant constituents. It is known that major problems related to the present photocatalytic system, which significantly limit their photocatalysis efficiency, are low-usage of visible light, fast recombination and also the low migration ability of the photo-generated electrons and holes. To solve the problem associated with conventional photocatalytic systems, recently hybrid photocatalysts containing carbon quantum dots (CQDs) have been proposed. The tunable photocatalytic characteristics of CQDs are widely mentioned. Moreover, the excellent photocatalytic activity of CQDs alone and in combination with photoactive species in the photo-degradation of organic pollutants was confirmed in the many reports. This work presents a comprehensive view of the application of CQDs to improve conventional photocatalytic systems in those studies which considered organic dyes as sample pollutants. In addition to providing detailed information regarding important roles of CQDs in photocatalytic activity enhancement, this review provides the comprehensive details about findings of the photocatalytic degradation of dyes using CQD-based photocatalysts and the best CQD-based composites photocatalysts are highlighted.

The efficacies of the sonolytic, photolytic and sonophotolytic activation of persulfate were investigated and compared for degradation of trichloroethylene in aqueous solutions. The effects of the operating variables on trichloroethylene removal efficiency were assessed and optimized by employing a response surface methodology based on central composite design. The investigated parameters include initial pH, persulfate concentration, ultrasound and ultraviolet power at initial concentration of 500 μg/L TCE. After 20 min, the sonophotolytic activation of persulfate resulted in 96.3% removal efficiency, while the corresponding removal values for the individual photolytic and sonolytic activation of persulfate were only 41.2 and 51.8%. These results indicate that the combination of sonolytic and photolytic activation of persulfate provides a synergistic effect with synergy index of 1.62. It was found that the trichloroethylene removal efficiency was enhanced with increasing persulfate concentrations, ultrasound and ultraviolet power with optimum values of 61 μmol/L, 95 and 60 W respectively, due to the formation of more reactive radicals. In addition, maximum trichloroethylene removal rate occurred at pH 5.5 and decreased when pH value was either decreased or increased from pH 5.5. At optimum condition, complete degradation of trichloroethylene was obtained at a 20-min reaction time. As indicated by the statistical analysis results, trichloroethylene removal efficiency was satisfactorily predicted using the proposed model developed with a very low probability of ˂0.0001 at a confidence level of 95%. Moreover, the quadratic model showed high correlation between the predicted and experimental data with high correlation coefficients of 0.9682 and 0.9539 for R2 and R a d j 2 , respectively. The sonophotolytic activation of persulfate for degrading trichloroethylene in an aqueous solution was proven to be an efficient technology.

The Fe(III)-doped Scoria was prepared to examine its potential use as an efficient sorbent for removal of fluoride and nitrate from water. Structure and morphology of raw scoria (RS) and Fe(III)-doped scoria (FeS) were studied by scanning electron microscopy, X-ray diffraction analysis and Fourier transform infrared spectroscopy. A four-factor central composite design combined with response surface modeling (RSM) was employed for maximizing fluoride and nitrate removal based on 30 different experimental data obtained in a batch system. At optimum condition, the maximum removal of fluoride and nitrate were 78.36% and 81.4%, respectively. The kinetic of fluoride and nitrate adsorption onto RS and FeS were followed the pseudo-first-order with high determination coefficient values (R2 > 0.997). The isotherm data of fluoride was fitted with the Freundlich model, whereas equilibrium data of nitrate are better fitted to the Langmuir isotherm model. The Langmuir maximum adsorption capacities of Fe(III)-doped scoria for fluoride and nitrate were 0.317 and 11.3 mg/g, respectively. In conclusion, Fe(III)-doped scoria is recommended as an economic and efficient sorbent for nitrate and fluoride removal from contaminated water.

The aim of this study is to survey the concentrations of air pollutants in rural and urban areas in Ahvaz city during two seasons. We used ANOVA to determine the differences between the areas. Paired t-test was used to compare the concentrations of the air pollutants in cold season and hot season. The concentration of the air pollutants in cold season was higher than warm season except for O3. Mobile vehicles represent the major source of air pollution in many areas, and the concentrations of traffic pollutants are greater near urban areas. The trend of changes in PM concentration in cold and warm seasons depends on dust storms occurrence.

Increased alcohol consumption, especially among young people, is a major concern in Turkey as it is around the world due to negative effects on public health and safety. Regarding this, it is pivotal to monitor and therefore control alcohol use in public. In this case, wastewater-based epidemiology (WBE), which is the in-depth analysis of wastewater and a relatively new method, can deliver complementary information concerning the abuse of different substances. The proven potential of the WBE approach offers new promises in the process of monitoring alcohol use, namely the monitoring of the levels of ethyl sulfate (EtS) as a urinary biomarker of alcohol consumption, and it is a powerful mean to estimate alcohol use at the community level. In this study, raw 24-h composite wastewater samples were collected from Seyhan and Yuregir wastewater treatment plants (WWTPs) in Adana Province for one week per season (October 2016–August 2017). The fast and validated analytical method was performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and therefore applied to the analysis of ethyl sulfate (EtS). Obtained concentration values were back-calculated, and regional and temporal social usage rates were determined. Higher values were calculated for both WWTPs on Sunday. Alcohol consumption in the region served by Seyhan WWTP was higher than Yuregir WWTP. The results showed that the levels of alcohol consumption during given periods in Adana ranged from 659.8 to 8998.7 mL/day/1000 per person with an average value of 4983.9 and 3924.2 mL/day/1000 inhabitant in Seyhan WWTP and Yuregir WWTP, respectively. This study shows that weekly and annual trends in alcohol consumption can be detected quickly from wastewater analysis.

Background & objectives This study investigates the role of environmental conditions, knowledge, attitudes and control measures of preventive behaviors in cutaneous leishmaniosis (CL) based on the BASNEF model in patients who referred to the health care centers of cities hit by earthquakes including Sarpol- Zahab and Qasr-Shirin in Kermanshah province, western Iran, in 2018. Method In this descriptive cross-sectional study, 128 individuals who visited rural and urban health centers in the cities under study were randomly selected. They were asked to fill in a structured questionnaire with questions about their demographic information, environmental conditions, their knowledge, attitude and preventive behavior regarding CL. Results The environmental conditions of participants (i.e. wastewater collection, solid waste disposal, drinking water and…) were at appropriate levels. Approximately 89.1% of the people used urban water supply networks while about 68% of participants had access to the wastewater collection system. About 67% of participants reported that their solid wastes were collected daily and disposed of in sanitary landfill. The most influential people in preventive behaviors (control actions) were family members (72.4%). Pearson’s correlation test showed that preventive behaviors had a meaningful correlation with understudy variables in BASNEF model (p

Exposure to potentially toxic elements (PTEs) via dust inhalation can endanger human health. In this regard, the dust samples from the streets of Kashan, Iran were collected to investigate the concentration of some PTEs such as Fe, Zn, Cu, Pb, Cr, Ni, and Cd by the aid of an inductively coupled plasma mass spectrometry (ICP-MS) while distribution and geoaccumulation analysis also were carried out. Also, the related health risk due to different exposure pathways of PTEs for the inhabitants of this city was assessed. The mean concentration of PTEs in the street dust was summarized as Fe (1.66 × 104 mg/kg)>Zn (2.37 × 102 mg/kg)>Cu (4.56 × 101 mg/kg)>Pb (4.52 × 101 mg/kg)>Cr (3.71 × 101 mg/kg)>Ni (1.36 × 101 mg/kg)>Cd (4.30 × 10−1 mg/kg). The rank order of PTEs based on mean geoaccumulation index (GAI) (Igeo) was Pb (2.77)>Zn (1.92)>Cu (1.06)>Fe (−0.64)>Cd (−0.90)>Cr (−0.97)>Ni (−1.15). Also, the rank order of target hazard quotient (THQ) for both adults and children was Fe > Pb > Cr > Zn > Cu > Ni > Cd, while the cancer risk (CR) for both adults and children was Cr > Ni > Cd. The total target hazard quotient (TTHQ) was measured as less than 1.0; therefore, residents of Kashan are not at considerable non-carcinogenic risk. Also, CR of Ni, Cd, and Cr exceeded the threshold value of 10−6; therefore, residents of Kashan are at considerable carcinogenic risk due to street dust in Kashan city. As a conclusion, approaching some controlling plans to decrease in emission of PTEs to ambient air is necessary.

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations., A high-resolution, global atlas of mortality of children under five years of age between 2000 and 2017 highlights subnational geographical inequalities in the distribution, rates and absolute counts of child deaths by age.

The presence of Legionella pneumophila (LP) in aquatic habitat is a global concern. The current study was undertaken to estimate the prevalence of LP in water systems with the aid of a systematic review and meta-analysis. The searching was performed among some international databases, including Scopus, PubMed, and Embase to retrieve the related articles between 1/January/1983 and 25/July/ 2017. Therefore, thirty-six articles (with 43 studies) out of 1,541 articles collected, were included in the meta-analysis. The overall prevalence of LP in water systems was determined as 20% (95%CI: 15-25). Also, the lowest and highest pooled prevalence of LP was observed in Poland (4% (95%CI: 0-13%)) and Kuwait (98% (95%CI: 90-100%)), respectively. The lowest and highest prevalence of LP-based on water resources subgroups was a water reservoir (15% (95%CI: 2-37%) and well (40% (95%CI: 26-50%), respectively. The number of studies that used polymerase chain reaction (PCR) for detection of LP was 16/43 (37.3%) while the culture method was 27/43 (62.7%). Generally speaking, the relatively high prevalence of LP among the investigated water systems was demonstrated, which should be reduced by performing appropriate control actions.

The presence of excess nitrate in groundwater limits it use as a drinking water supply and its removal is critical to balance the nitrogen cycle in aquatic systems. In this study, ultra-thin 2-dimensional Ag-TiO

A novel enhanced visible light absorption BiOCl/AgCl/BiVO4 heterojunction of photocatalysts could be obtained through a one-pot hydrothermal method used with two different pH solutions. There was a relationship between synthesis pH and the ratio of BiOCl to BiVO4 in XRD planes and their photocatalytic activity. The visible light photocatalytic performances of photocatalysts were evaluated via degradation of diclofenac (DCFF) as a pharmaceutical model pollutant. Furthermore, kinetic studies showed that DCF degradation followed pseudo-first-order kinetics. The photocatalytic degradation rates of BiOCl/AgCl/BiVO4 synthesized at pH = 1.2 and pH = 4 for DCF were 72% and 47%, respectively, showing the higher activity of the photocatalyst which was synthesized at a lower pH value. It was concluded that the excellent photocatalytic activity of BiOCl/AgCl/BiVO4 is due to the enhanced visible light absorption formation of a heterostructure, which increased the lifetime of photo-produced electron&ndash, hole pairs by creating a heterojunction. The influence of pH during synthesis on photocatalytic activity in order to create different phases was investigated. This work suggests that the BiOCl/AgCl/BiVO4 p-n heterojunction is more active when the ratio of BiOCl to BiVO4 is smaller, and this could be achieved simply by the pH adjustment. This is a promising method of modifying the photocatalyst for the purpose of pollutant degradation under visible light illumination.

A novel enhanced visible light absorption BiOCl/AgCl/BiVO4 heterojunction of photocatalysts could be obtained through a one-pot hydrothermal method used with two different pH solutions. There was a relationship between synthesis pH and the ratio of BiOCl to BiVO4 in XRD planes and their photocatalytic activity. The visible light photocatalytic performances of photocatalysts were evaluated via degradation of diclofenac (DCFF) as a pharmaceutical model pollutant. Furthermore, kinetic studies showed that DCF degradation followed pseudo-first-order kinetics. The photocatalytic degradation rates of BiOCl/AgCl/BiVO4 synthesized at pH = 1.2 and pH = 4 for DCF were 72% and 47%, respectively, showing the higher activity of the photocatalyst which was synthesized at a lower pH value. It was concluded that the excellent photocatalytic activity of BiOCl/AgCl/BiVO4 is due to the enhanced visible light absorption formation of a heterostructure, which increased the lifetime of photo-produced electron–hole pairs by creating a heterojunction. The influence of pH during synthesis on photocatalytic activity in order to create different phases was investigated. This work suggests that the BiOCl/AgCl/BiVO4 p-n heterojunction is more active when the ratio of BiOCl to BiVO4 is smaller, and this could be achieved simply by the pH adjustment. This is a promising method of modifying the photocatalyst for the purpose of pollutant degradation under visible light illumination.

Adsorption is one of the excellent ways for heavy metal removal from aqueous solution because of advantages like the low cost, availability, profitability, ease of operation and efficiency. In this study, adsorption potential of a low cost adsorbent Hibiscus Cannabinus kenaf was investigated for Cr(VI) removal from water using batch and continuous mode experiments. Optimum removal of Cr(VI) ions was occurred at pH 7. The kinetic results showed that the Cr(VI) removal followed intraparticle diffusion kinetics with a correlation coefficient greater than 0.94. The adsorption isotherms of Cr(VI) could be described very well by both the Langmuir and Freundlich equations (R2=0.997). The maximum Cr(VI) uptake was found to be 582 µg/g in Langmuir model. Column studies have been carried out to compare these with batch capacities. The Yoon–Nelson and Thomas models were found appropriate for description of the breakthrough curve, whereas the Bohart–Adams model was not match very well. The recovery of Cr(VI) and chemical regeneration of the spent kenaf have also been studied. The high Cr(VI) adsorption capacity and regeneration efficiency of kenaf suggests it as a promising alternative for heavy metal removal specially at near circumneutral pH.

Efficiency in the sonochemical degradation of amoxicillin using sulfate radicals as a function of initial concentration of amoxicillin, Ag2SO4, Na2S2O8 concentration and power of ultrasonic irradiation was studied. A central composite design (CCD) with response surface methodology (RSM) was used to investigate the influence of individual and interaction of operating variables on removal efficiency with the aim of recognizing the optimum operating conditions. Satisfactory prediction based on a quadratic model with very low probabilities ( 98% in a 60 min reaction time. This study effectively demonstrated the usage and advantages of response surface methodology for the modeling and prediction of process response. It was observed that the sulfate radical-based advanced oxidation process (SR-AOP) is an effective and efficient technology for the mineralization of amoxicillin in aqueous solution.

Discharging the effluents of textile wastewaters into potable water resources can endanger the ecosystem, due to their reactivity, toxicity, and chemical stability. In this research, the application of powder activated carbon modified with magnetite nanoparticles (PAC-MNPs) as an adsorbent for removal of reactive dyes (Reactive black 5 (RB5) and reactive red 120 (RR120)) was studied in a batch system. The adsorption performance was evaluated as a function of temperature, contact time and different adsorbent and adsorbate concentrations. The levels of factors were statistically optimized using Box-Behnken Design (BBD) from the response surface methodology (RSM) to maximize the efficiency of the system. The adsorption process of both dyes was fit with the pseudo-second order kinetic and Langmuir isotherm models. The identified optimum conditions of adsorption were 38.7 °C, 46.3 min, 0.8 g/L and 102 mg/L for temperature, contact time, adsorbent dose, and initial dyes concentration, respectively. According to the Langmuir isotherm, the maximum sorption capacities of 175.4 and 172.4 mg/g were obtained for RB5 and RR120, respectively. Thermodynamics studies indicated that the adsorption process of the reactive dyes was spontaneous, feasible, and endothermic. After five cycles, the adsorption efficiency was around 84 and 83% for RB5 and RR120, respectively. A high value of desorption was achieved, suggesting that the PAC-MNPs have a good potential in regeneration and reusability, and also can be effectively utilized in industrial applications. PAC-MNPs also show a good anti-interference potential for removal of reactive dyes in dye-industry wastewaters.

The nitrogen doped TiO2 (N-TiO2) was synthesized via a facile hydrothermal method using titanium (IV) butoxide as a titanium precursor and urea as a dopant source. The catalyst was characterized by transmission electron microscopy (TEM), X-ray diffractometry (XRD), surface area (BET method) and band gap energy by diffuse reflectance spectroscopy (DRS). N-TiO2 is a mesoporous nanocrystal sheet with the mean pore diameter of 14.9 nm, specific surface area of 66.3 m2/g, crystallite size of 27 nm, and band gap energy of 2.83 eV. Response surface methodology (RSM) with central composite design (CCD) was utilized for the modeling and optimization of the operational photodegradation variables such as pH, catalyst loading, initial diazinon concentration, and irradiation time. Under the optimum conditions established, the performance of 85% and 63% for degradation and mineralization of diazinon were experimentally reached, respectively. Moreover, the obtained quadratic model showed high correlation (R2 = 0.95 (degradation) and R2 = 0.928 (mineralization)) between the predicted and experimental values. It was found that all the selected variables had an important effect on diazinon removal.

An advanced, eco-efficient “waste plus waste to hydrogen” method was developed for hydrogen generation and the simultaneous treatment of two types of waste generated from magnesium and brewery-based industries via hydrolysis. The hydrolysis of Mg scraps was carried out using brewery wastewater and the reaction was accelerated with acetic acid (aa) at different concentrations (0, 12, 18, 24 and 30 wt% aa). The concentration of pollutants such as cyclortisiloxane-hexamethyle (C6H18O3Si3), which are persistent in conventional wastewater treatment, was successfully reduced. After the hydrolysis of the wastewater, 62.4% of chemical oxygen demand (COD) reduction and the complete colour removal were observed. The highest hydrogen generation, about 0.99 NL/min (>60% H2 yield in 5 min), was observed in the presence of 30 wt% aa concentration in the hydrolysis reaction. This study proposes an eco-efficient hydrogen generation and waste treatment method as it simultaneously degrades pollutants and produces hydrogen utilizing Mg scrap waste and brewery wastewater without additional energy consumption.