The present paper aims at investigating the applicability of hybrid cells in the series model for pollution transport inside the layered porous media. For this purpose, four layers of rock material have fallen inside the experimental flume, with eight sensors installed longitudinally inside the media to obtain experimental BTCs. In order to measure time parameters of the model, named , two different methods of LSCF and MM have been examined. The model's sensitivity as well as its temporal equations with different parameters have been assessed. Finally, results show that at the fixed time step, the model is more sensitive to parameter (advection zone time parameter) rather than residential time parameters, to which the moment relations are more sensitive. A detailed computation of the related transport parameters has been operated and the Peclet number, crossing velocity, dispersion coefficient, time to the max, and maximum concentration have been calculated. Eventually, the model's applicability for large-scale porous media has been proven with only one unit of the cells.

With the growth and development of chemical plants, the amount of mercury released in wastewater has increased. Mercury in wastewater contains harmful compounds which are hazardous to the human health and living organisms. Therefore, its removal from wastewater is significant. There are various techniques or methods available for removing mercury from aqueous solutions. This study focused upon the removal of mercury from aqueous solution with commercial activated carbon and activated carbon from sugarcane bagasse.  Activated carbon produced from sugarcane bagasse was used as adsorbent. This adsorbent was used to remove mercury from aqueous solution. For this purpose, first, the optimal mercury solution pH for mercury removal was obtained. Effective parameters such as contact time, initial concentration of mercury, adsorbent dose and agitation speed were investigated. The mercury adsorption was increased when the mass of activated carbon was increased. Increasing the initial mercury concentration leads to decrease in mercury adsorption efficiency. The results of experiments indicated that the speed of the stirrer was not considered to be an effective factor in the mercury adsorption. Experiments were also carried out on a commercial activated carbon. Adsorption results obtained for sugarcane bagasse activated carbon were compared with commercial activated carbon.  The adsorption efficiency was increased as the contact time was increased.  Finally, the experiment was carried out on water samples released from South Pars platforms. In addition to the mercury removal, other heavy metals removal such as lead and cadmium were also carried out.

Although complexity and vulnerability assessment of mountain landscapes is increasingly taken into consideration, less attention is paid to ecophronesis-based solutions so as to reduce the fragile ecosystem vulnerability. The main propose of this study is to provide an insight of mountain complex landscape vulnerability and propose ecophronesis-based solutions in strategic planning framework for reduction of vulnerability. The study has been carried out by following five steps in Chelgard Mountain landscapes (center of Iran): First, it determines the evaluation framework on basis of rapid literature review. Second, the vulnerability is assessed, using Analytic Hierarchy Process (AHP), in accordance with experts’ opinion. In the third step, the results provide a zoning map of vulnerability. Afterwards, the study suggests a strategic plan to manage the area environmentally and, finally, the solutions are proposed, based on ecophronesis, in order to not only solve the plight but also reduce the vulnerability. Results from the vulnerability assessment indicate that anthropogenic stressors intensify the vulnerability. While local ecological wisdom is shaped over time in the area, its application faces challenges as a result of rapid and immense socio-economic changes. It seems that sustainability of mountain ecosystem needs to regenerate social structures on basis of socio-ecological capital. Main characteristics of these adopted social structures include their balance with the ecosystem and adoption with new lifestyles.

Flourene and phenanthrene are organic compounds with high hydrophobicity and toxicity. Being recalcitrant in nature they are accumulating in the environment at an alarming concentration, posing serious threat to living beings. Thus in the present study, microorganisms were screened for their ability to degrade these contaminants at high concentrations in least period of time. Two out of fifteen isolates screened showed growth in basal medium containing 25 mg/l of fluorene/phenanthrene as the only carbon source. These selected isolates were acclimatised with step wise increased concentrations of flourene/phenanthrene for 165 days in basal medium. The acclimatised strains were identified and characterised on the basis of their morphological and biochemical characteristics and 16S rRNA gene sequence analysis. Results showed close relatedness of the isolates to Pseudomonas aeruginosa sp. and Bacillus safensis sp. Biodegradation studies carried out with these acclimatised strains at optimum conditions (pH 7 and temperature 30°C) showed 62.44% degradation of fluorene and 54.21% of phenanthrene in 10 days by Pseudomonas sp. VB92, whereas, Bacillus sp. JK17 degraded 43.64% of fluorene and 59.91% of phenanthrene in 12 days, at an initial concentration of 200 mg/l, as determined by HPTLC. During fluorene degradation by Pseudomonas sp. VB92, one metabolite was identified as fluorene,1,4-dihydro. An anionic biosurfactant (emulsification index of 80%) produced by strain VB92 during growth with PAHs, improved its degradation rate. This showed strong potential of the acclimatised strains for bioremediation and reclamation of polyaromatic hydrocarbon contaminated sites.

Soil contamination by heavy metals has increased noticeably within the past years. Unlike organic compounds, metals cannot degrade; therefore effective cleanup is required to reduce its toxicity. This experiment was undertaken to investigate the comparative potential of Panicum maximum and Axonopus compressus to bioremediate zinc polluted soils, the impact of Zn on the antioxidant defense system of the plant, assaying for activities of antioxidants proteins. Zinc salts were mixed with soil at various concentrations 5 mg/kg, 10 mg/kg, 20 mg/kg and 40 mg/kg in triplicates and control was setup. After 4 months, the plants (root, shoot and leaf) and soil were analyzed for morphological, biochemical parameters and Zn concentration. The root length of P. maximum and A. compressus decreased as the concentration of zinc increased. The least shoot length inhibition of A. compressus was 6.16% (5 mg/kg) while the highest shoot length inhibition was 40.14% (40 mg/kg). The least shoot length inhibition of Panicum maximum was 6.16% exposed to 5 mg/kg and the highest shoot length inhibition was 53.13% (40 mg/kg). There was significant reduction of the heavy metals in vegetated soils for P. maximum and A. compressus at the end of the study compared to the heavy metals in the soils at the beginning of the study (p<0.05). P. maximum, is a better removal of Zn than A. compressus, however, it was not significant. Glutathione levels varied significantly (p≤ 0.05) with respect to heavy metals. A. compressus has more effects on Glutathione activities than P. maximum. Zn caused a decrease in metallothionein level in P. maximum while A. compressus metallothionein level increased.

The present study focuses on effects of initial pH on dibenzothiophene (DBT) desulfurization via 4S pathway by growing cells of Ralstonia eutropha. For so doing, temporal changes of biomass concentration, glucose as a sole carbon source, pH value, and 2-hydroxybiphenyl (2-HBP) formation have been monitored during the bioprocess. The biomass concentration has been modeled by the logistic equation and results show that the values of maximum specific growth rate (μmax) and maximum cell concentration (Xmax) have increased in line with the rise of initial pH from 6 to 9. This confirms the effect of pH on the energetics of cell growth via altering the proton gradient and manipulating ATP-related metabolic pathways. By considering the Pirt’s maintenance concept, the bioenergetic aspects of DBT desulfurization process are affected by changes in pH, where the maximum specific DBT conversion rate (0.0014 mmol/gcell.h) has been obtained at initial pH of 8. Additionally, the kinetic modeling of the 2-HBP formation through the Luedeking-Piret model indicates that the DBT desulfurization rate is linearly related to the cell growth rate, instead of biomass concentration. The growth associated and non-growth associated 2-HBP formation constants have been obtained 3.82 mg2-HBP/gcell and 0.06 mg2-HBP/gcell.h, respectively at an initial pH of 8.

The transport mechanism of contaminated groundwater has been a problematic issue for many decades, mainly due to the bad impact of the contaminants on the quality of the groundwater system. In this paper, the exact solution of two-dimensional advection-dispersion equation (ADE) is derived for a semi-infinite porous media with spatially dependent initial and uniform/flux boundary conditions. The flow velocity is considered temporally dependent in homogeneous media however, both spatially and temporally dependent is considered in heterogeneous porous media. First-order degradation term is taken into account to obtain a solution using Laplace Transformation Technique (LTT) for both the medium. The solute concentration distribution and breakthrough are depicted graphically. The effect of different transport parameters is studied through proposed analytical investigation. Advection-dispersion theory of contaminant mass transport in porous media is employed. Numerical solution is also obtained using Crank Nicholson method and compared with analytical result. Furthermore, accuracy of the result is discussed with root mean square error (RMSE) for both the medium. This study has developed a transport and prediction 2-D model that allows the early remediation and removal of possible pollutant in both the porous structures. The result may also be used as a preliminary predictive tool for groundwater resource and management.

Management of solid wastes is considered as an economic and environmental issue in the building stone industry. The current study uses raw and calcined calcareous sludge, generated in the stone cutting factories, in order to remove sulfur dioxide. Sludge characterization has been performed, using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) analyses. The removal experiments of sulfur dioxide have conducted under different humid contents and adsorbent doses. The results showed that the higher the adsorbent dosage and humidity content, the greater the SO2 adsorption.. The calcination process at temperatures of 400, 500, 600, and 700℃ revealed that with rising calcination temperature and humidity content, the adsorbent capability is enhanced considerably. This method could be developed for the management of stone sludge produced from the stone cutting industry through its conversion into an effective and low-cost adsorbent for desulfurization process.

The city of Tehran undergoes an increasing growth in population as well as industrial activities, both of which increase the concentration of air pollutants. The current research tries to turn a limited and focused system of air contamination measurement and control to an unlimited and extensive one that examines the concentration of each of the contaminants in any area of Tehran. Accordingly, information from twenty air-pollution measurement stations at certain points of the city helps measuring the concentrations of contaminants like SO2, NO2, CO, O3, PM2.5, and PM10 throughout a year on a daily basis. The index of AQI has also been used as the air quality index to determine the level of pollution in the city. Using ARC-GIS software, the AQI or the air quality index has been zoned and a comprehensive map, designed. Moreover, in order to illustrate this map, a map of the zoning has been drawn up for this purpose on December, 26, 2016, considered an unhealthy day in Tehran, the results of which show that only 27.8% of the city is unhealthy and the rest of the city does not fall in unhealthy area. However, due to the lack of a comprehensive map for determining the AQI in different parts of the city, the whole city closes down, leading in an economic loss of about $ 1 million a day for the city.

In this study, the lethal toxicity, behavioral responses and hematotoxicity of formulated chlorpyrifos on Clarias gariepinus was evaluated. C. gariepinus fingerlings were exposed to 0.2 mg/L, 0.25 mg/L, 0.3 mg/L, 0.35 mg/L and 0.4 mg/L of the active ingredient chlorpyrifos to determine the lethal concentrations and behavioral effects. C. gariepinus juveniles (38.84±7.67g) were then exposed to 0.0256 mg/L and 0.0128 mg/L for 14 days to study somatic indices and haematological effects. The 24h, 48h, 72h and 96h LC50 were estimated as 0.292 (0.210 – 0.376) mg/L, 0.275 (0.252 – 0.297) mg/L, 0.263 (0.242 – 0.282) mg/L, and 0.256 (0.235 – 0.275) mg/L respectively. Hyper activity, loss of equilibrium, erratic swimming, trembling, respiratory distress and poor startle response were observed in fingerlings in response to acute toxic stress of chlorpyrifos. Liver somatic index (LSI) of exposed juveniles increased significantly (p<0.05) compared with control, while there was no statistically significant difference in all the haematological parameters of the exposed fishes compared with the control (p<0.05). The results indicate that the chlorpyrifos formulation was highly toxic and induced behavioral changes in C gariepinus fingerlings, while sub-lethal concentrations induced inflammation in the liver but had no effect on haematological parameters of Clarias gariepinus juveniles. LSI was sensitive to the sub-lethal concentrations and could serve as indicators or exposure to organophosphate insecticides.