The aim of this study is to synthesize and characterize an economical and environmentally-friendly adsorbent with high adsorption capacity. For this purpose, the walnut shells (Juglans regia L.) were chemically modified using sulfuric and citric acids, separately. After pyrolysis and synthesis of activated carbon (AC), the optimization of conditions at the preconcentration/removal step was performed using parameters such as pH and contact time for uranium in the model solutions. The measurements were carried out by inductively coupled plasma-mass spectrometry (ICP-MS). From the shapes of the BET isotherms, it may be stated that activated carbon exhibit type I. It was found that the surface area and total pore volume of the activated carbon were 696.6 m2/g and 0.35 mL/g, respectively. The adsorption capacity was found to be 220 mg/g. It was found that the optimum pH is 6.0 for preconcentration/removal using AC obtained by sulfuric acid as chemically-modifier. The optimized method was applied to determination of U at ng/mL levels in the model solutions.

The study investigates the effect of aluminium oxide nanoparticles as an additive to Madhuca Indica (mahua) methyl ester blends on performance, emission analysis of a single-cylinder direct injection diesel engine operated at a constant speed at different operating conditions. The test fuels are indicated as B10A0.2, B10A0.4, B20A0.2, B20A0.4 and diesel respectively. The results indicate that the brake thermal efficiency for aluminium oxide nanoparticles blended biodiesel increases slightly when compared to the mineral diesel. The carbon monoxide (CO), unburnt hydrocarbon (HC) and smoke emission marginally decrease as compared to mineral diesel. Oxides of nitrogen (NOx) emissions are minimum for the aluminium oxide nanoparticles blended mahua methyl esters. Higher cylinder gas pressure and heat release rate were observed for aluminium oxide nanoparticles blended mahua methyl ester. From the study, the blending of aluminium oxide nanoparticles in biodiesel blends produces a most promising results in engine performance and also reduces the harmful emission from the engines.

Air quality prediction is highly important in view of the health impacts caused by exposure to air pollutants in urban air. This work has presented a model based on support vector machine (SVM) technique to predict daily average carbon monoxide (CO) concentrations in the atmosphere of Tehran. Two types of SVM regression models, i.e. -SVM and -SVM techniques, were used to predict average daily CO concentration as a function of 12 input variables. Then, forward selection (FS) technique was applied to reduce the number of input variables. After converting 12 input variables to 7 using the FS, they were fed to SVM models (FS-(-SVM) and FS-(-SVM)). Finally, a comparison among SVM models operation and previously developed techniques, i.e. classical regression model and artificial intelligent methods such as ANN and adaptive neuro-fuzzy inference system (ANFIS) was carried out. Determination of coefficient (R2) and mean absolute error (MAE) for -SVM (-SVM) were 0.87 (0.40) and 0.87 (0.41), respectively, while they were 0.90 (0.39) and 0.91 (0.35) for ANN and ANFIS, respectively. Results of developed SVM models indicated that both FS-(-SVM) and FS-(-SVM) regression techniques were superior. Furthermore, it was founded that the performance of FS-(-SVM) and FS-(-SVM) models were generally a bit better than the best FS-ANFIS and FS-ANN solutions for short term forecasting of CO concentrations.

The main objective of this study is to evaluate heavy metals contamination of highly consumed vegetables and hazardous effects of consuming these vegetables. The study was conducted in vegetable fields in three different regions according to the level of environmental pollutions, including "Isfahan", "Flavarjan" and "Faridan, Golpayegan and Natanz". Six types of vegetables in each field with three replicates in each region were selected in the summer of 2017 by the random sampling method from vegetable fields. The level of heavy metals (Pb, Cu, Co, Cd and Cr) in vegetables has been measured for each sample. The result showed that in the Isfahan region, the highest daily intake of Pb, Cu, Co, Cd and Cr for the consumption of all the vegetables was obtained in the recipients. The highest target hazard quotient for non-cancerous diseases of contaminated vegetables was 28.9 and 21.1 in "Isfahan" for children and adults, respectively. The target hazard quotient for vegetable consumption was greater than one and at high hazard for both age groups. The principal component analysis showed that the contamination by the heavy metals in the "Isfahan" and "Falavarjan" regions overlapped and the risk of contamination of heavy metals in urban vegetables in both regions increased the hazard of non-cancerous diseases. It is highly recommended that the quality standards of foods that are imposed on the production of food crops.

Microbial fuel cell represents an emerging technology to attain electrical energy from wastewater. There are several alternative methods available for wastewater treatment; Microbial fuel cell is one of them, which generates green energy from wastewater for making a contribution to renewable sources of energy. This study states the performance of microbial fuel cell with different parameters i.e., catholyte, electrodes, and initial COD concentration. Sodium chloride was used as catholyte and graphite rods were used as both electrodes. The sodium chloride concentrations in the cathode and initial chemical oxygen demand have also been optimized. The optimum sodium chloride of 70 mM in the cathode solution generates the maximum power density of 408.98μW/m2. As the sodium chloride concentration increases in catholyte, the capacity for power production also increases. The voltage output of Microbial fuel cell increases when the initial concentration of chemical oxygen demand increases to a peak value of 1500 mg/l and if the value exceeds this limit, the performance of Microbial fuel cell (in terms of voltage) starts decreasing. The chemical oxygen demand removal efficiency of a microbial fuel cell with simple graphite electrode and graphite electrodes with coated iron were 79% and 90% respectively.

Mathematical models for pollutant transport in semi-infinite aquifers are based on the advection-dispersion equation (ADE) and its variants. This study employs the ADE incorporating time-dependent dispersion and velocity and space-time dependent source and sink, expressed by one function. The dispersion theory allows mechanical dispersion to be directly proportional to seepage velocity. Initially the aquifer is assumed contaminant free and an additional source term is considered at the inlet boundary. A flux type boundary condition is considered in the semi-infinite part of the domain. Laplace transform technique (LTT) is then applied to obtain a closed form analytical solution. The effect of source/sink term as a function in the one-dimensional advection-dispersion equation is explained through the graphical representation for the set of input data based on similar data available in hydrological literature. Matlab software is used to obtain the graphical representation of the obtained solution. The obtained analytical solution of the proposed model may be helpful in the groundwater hydrology areas.

Formaldehyde has been documented to be naturally present in many common foods. There has been a big public concern over the use of formaldehyde in the preservation of food. Also, it is commonly used as a chemical substance, usually in the life and can interact with many bio-substance in the human body. The present study target to investigate the protective effects of  Cymbopogon schoenanthus (CS) extract against the reproductive and carcinogenic effects of formaldehyde on male rats. The Albino male rats were divided into equal six groups, first group: rendered as a control group; second group: received formalin (100 mg/kg bw) and third group and forth group: were received SC extract at (50 and 100 mg) respectively; fifth group and sixth group were received formalin (100mg /kg bw) + SC extract (50mg) and formalin (100mg /kg bw)+ SC extract (100 mg) respectively. At the end of the experiment the animals were scarified and blood samples were collected for measurement all tested parameters. The results showed that the oral exposure to formaldehyde at a dose of 100 mg/kg bw resulted in significant negative effects in all tested parameters, while the CS extract at tow doses (50 and 100 mg) alone or in combination with formalin restored the negative effects to normal levels compared with the untreated group. The histopathological examination was studied on testis tissues and the histopathological pictures showed the CS extract at tow mention doses had ameliorate the adverse effects that induced by formaldehyde hazards.

The entrance of Cd (II) to aqueous environments causes a major problem to human health. The current article examines the efficiency of TiO2 and γ-Al2O3 nanoparticles in Cd (II) removal from aqueous medium as influenced by different chemical factors, such as pH, initial concentration, background electrolyte, and ionic strength, in accordance with standard experimental methods. It conducts Batch experiments, fitting various isotherm models (Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich) to the equilibrium data. Saturation indices (SI) of TiO2 and γ-Al2O3 nanosorbents indicate that adsorption is a predominant mechanism for Cd (II) removal from aqueous solution, giving maximum Cd (II) adsorption rates of 3348 and 1173 mg/kg for TiO2 and γ-Al2O3 nanoparticles, respectively, both obtained at the highest pH level (pH = 8) as well as the highest initial Cd (II) concentration (equal to 80 mg/ L). Cadmium removal efficiency with TiO2 and γ-Al2O3 nanoparticles has increased by raising pH from 6 to 8. The Freundlich adsorption isotherm model could fit the experimental equilibrium data well at different pH levels. Also, it has been revealed that cadmium adsorption drops as the ionic strength is increased. The maximum Cd (II) adsorption (1625 mg/kg) has been attained at 0.01 M ionic strength in the presence of NaCl. Thermodynamic calculations demonstrate the spontaneous nature of Cd (II) adsorption by TiO2 and γ-Al2O3 nanoparticles. The former (TiO2) have high adsorption capacities, suggesting they are probably effective metal sorbents, compared to the latter (γ-Al2O3).

In the present study, size-segregated samples of PM were collected from urban and semi-urban traffic junctions in Agra, India. PM samples were collected during the monsoon season (July to September 2015) using Grimm portable aerosol Spectrometer. The recorded mean concentration of PM10 at urban site was 137.09±61μg/m3 and at semi-urban site was 270.14±21μg/m3, which were higher than the suggested limits by WHO and NAAQS India. Mean concentrations of PM2.5 were 41.45±40μg/m3, 48.88±34μg/m3 at the urban and semi-urban site, respectively. Whereas, mean concentrations of PM1.0 were 30.35±64μg/m3, 12.64±4μg/m3 and PM0.25 were 0.06±0.05μg/m3, 0.17±0.06μg/m3 at the urban and semi-urban site, respectively. It was estimated that PM10, PM2.5 and PM0.25 values were higher at semi-urban site than urban sampling site but in case of PM1.0 concentrations were higher at urban site. The surface morphology of PM2.5 was studied using Scanning Electron Microscope (SEM). The results show flaky, branched chain like aggregates of carbon bearing spheres at the urban site while cluster, branched, spherical and fluffy particles at semi-urban site. The presences of carbonaceous particles were enhanced due to use of fuel combustion. Chemical analysis was done using ICP-AES. Concentrations of Zn and Cu were found higher while Ni was least in comparison to other metals. Elemental composition present in PM2.5 was used to calculate the health risk assessment to identify the possible health effect on human health, hazards quotient (HQ) values was found higher as Ingestion to inhalation pathways while ECR values found higher as Cr(VI)>Ni>Pb for both medium (Air and Dust).

Groundwater plays a pivotal role as the largest potable water sources in Bangladesh. As agriculture is widely practiced in Bangladesh, potential nitrate (NO3¯) pollution may occur. Besides, excess amount of arsenic (As) has already been found in groundwater in many parts of Bangladesh including the present study area. Thus, this study was conducted to assess the NO3¯ status along with some trace metals and associated human health risk in the Central Bangladesh. A total of 99 groundwater samples were analyzed to assess human health risk due to high level of NO3¯ and other trace elements i.e. arsenic (As), iron (Fe), and manganese (Mn). Concentration of NO3¯ was determined using column chromatography and inductively coupled plasma optical emission spectrometer (ICP-OES) was used to measure As, Fe and Mn concentrations. It was found that the mean concentration of NO3¯ 253.17 (mg/L) in the groundwater samples exceeds the recommended guideline value by the WHO (50 mg/L). Moreover, this study area also characterized with elevated concentration of As (19.44 μg/L), Fe (811.35 μg/L), and Mn (455.18 μg/L) in the groundwater. Non-carcinogenic human health risk was calculated by justifying HQ (Hazard Quotient) and HI (Hazard Index) and attributed potential conjunctive human health risks due to NO3¯, As, Fe and Mn in the study area. Child (9.941) is more vulnerable than adult (7.810) considering non-carcinogenic human health risk. Moreover, high carcinogenic risk was found due to As contamination in the groundwater samples and children (1.94×10-3) are more susceptible to carcinogenic risk compared to adults (9.2×10-4).