JOURNAL OF ENVIRONMENT AND WATER ENGINEERING
Year:2018 | Volume:4 | Issue:1 |Papers Count:8

Many financial and living expenses are caused annually due to the destruction of bridges in the flood events. Studies show that changes in bridges' geometry can lead to changes in the time to reach maximum scouring. The purpose of this study was to investigate the time variation of scour depth at the bridge pier. For this purpose, a laboratory flume with a length of 14 meters, a width of 1. 5 meters and a height of 0. 7 meters was used. Four different forms of the slot were created on the rectangular pier including two rectangular (vertical and horizontal), square and diamond slots. Experiments were carried out at three levels: above the bed, on the bed and under the bed at four flow rates of 21. 2, 25. 6, 29 and 32 l/s in sediments with a mean diameter of 0. 5 mm. The results of this study showed that the scour rate is higher in the first minutes of the start of the test. Over time, the intensity of changes is reduced. increasing the depth and volume of the scour hole, decreases the intensity of the changes. Moreover, there is a delay between Approaching the dimensionless scour number to a certain degree and next changes in this parameter, which indicates that in a flood event, performing emergency measures could be effective. In addition, at a given time, placing slot at the top of bed increased the scouring dimensionless number by twice rather than placing under the bed.

Organic hydrocarbons as a result of carcinogenesis and mutation caused many concerns. In this research, straw and chalk absorber was used as an organic adsorbent to remove oil pollution from wastewater. The adsorption experiments were performed discontinuously using oil-containing laboratory solutions. Optimum adsorption conditions were obtained by changing the factors affecting adsorption including pH, initial concentration of contaminant, contact time and adsorbent amount on adsorption at different levels, the oil absorption was determined by weighting method. Ultimately, the use of adsorbent for laboratory wastewater was studied. The highest absorbent efficiency at the time of equilibrium was observed for absorbing oil in 15 minutes a bout 28. 85% absorbance, which did not have a significant difference with other contact times, which could be due to low contact time and the lowest value was observed with a significant difference of 3 minutes about 17. 82% absorption, with the absorption rate being most significant in relation to the time of low, due to increased absorption time Increases. The highest rate of straw absorption was observed in pH = 7, which did not have a significant difference with other pH about36. 95% absorption and the lowest percentage of adsorption was observed at pH = 9, which had no significant difference with other pHs (19. 09% absorption; P <0. 05). The effect of straw absorbent values in 2 g/L was significantly higher than other amount of adsorbents about 61. 05% absorption and the lowest percentage of adsorption was significantly different from other values in 0. 25 and 0. 5 grams per liter about 25. 92%. Therefore, it can be concluded that the straw absorbent, in the form of adding more contact time, has a high efficiency in absorbing oil from wastewater and can be used in the treatment of industrial wastewater.

Textile pollutants, especially dyes are toxic compared to other pollutants and their presence is more sense in the environment. Reactive dye due to its high molecular weight and aromatic structure is more dangerous than other dyes. These dyes are highly soluble in water and are not easily removed by common treatment methods. Among the methods of wastewater treatment, application of membrane filtration via nanofibers can be more effective, since these membranes are very porous and their pores are interconnected; moreover, they can easily be functionalized. This research aimed at removal of reactive blue 19 dye from the simulated dyeing effluent using adsorbent through a membrane produced by electrospinning of the PVA solution. In this regard, the influence of different parameters on the fiber production conditions such as polymer concentration, applied voltage intensity, distance of nozzle to collector and feeding rate were investigated. In addition, effects of environmental factors including pH and temperature, contact time and nanofiber mass on the dye removal efficiency were studied. The very fine nanofiber was produced by 1. 7% wt PVA at 15 kV with 1. 0 ml/h feeding rate from 13 cm. The research found 91% dye removal efficiency using prepared nanofibers at pH 2. 1, 35˚ C and 20 mg/l nanofibers. The results indicate that the process of dye adsorption on the nanofiber mass is endothermic.

It is essential to remove dye products from wastewater. The main aim of the present study was to investigate the efficiency of marble powder as an adsorbent for removal of BR 46 dye from aqueous solution. This study was performed experimentally at laboratory scale and in a batch system. In this research, the effect of initial dye concentration, absorbent dosage, contact time and pH on efficiency of dye removal were investigated. SEM, XRD and FT-IR were used to characterize the marble powder. Langmuir and Freundlich adsorption isotherms were selected to explicate the interaction of the dye and adsorbent. Two kinetic models (the pseudo-first-order and the pseudo-second-order) were used to calculate the adsorption rate constants. The results showed that the efficiency of dye removal was increased with increasing adsorbent dosage and by increasing adsorbent dose from 0. 05 to 2 g/l, dye removal efficiency was increased from 82. 91 to 87. 55%. The highest dye removal efficiency (56. 9%) was obtained in pH= 9. By decreasing initial dye concentration from 30 to 250 mg/l, dye removal efficiency was increased from 90. 84 to 56. 7%. The appropriate time period to get the maximum of dye adsorption and equilibrium state was 90 min. The results also showed that the adsorption of Basic Red 46 followed the Langmuir isotherm model (r2= 0. 89). Moreover, results indicated that the adsorption kinetics of the dye followed pseudo-second-order model. Compared to the other expensive dye removal methods, the marble powder can be considered as a non-expensive adsorbent for the removal of BR 46 from aqueous solution.

Temperature is one of the major parameters of plant growth and influences the amount of water requirement. Therefore, in this paper, the future temperature trend in the Abhar area was studied under the influence of climate change during the future time periods and compared with the observation period. In this way, the observation period of 1986-2010, the horizon near 2045-2011, the middle horizon of 2046-2070, and the far horizon of 2080-2100 was considered. The LARS-WG software was used in order to downscale, scenario file generation and general circulation atmospheric model simulation. In order to simulate the climate was used, the HadCM3 model by A2 scenario. In generating a scenario file, the numbers of both series (GCM PREDICTIONS and LARS-WG PARAMETERS) were considered, and the scenario file was generated for each of the three horizons future near, middle and far. The results of this study show the increasing trend of minimum, average and maximum temperature parameters over the next horizons. The amounts of the increase of the parameters studied during the mentioned horizons, respectively, in the parameter of the minimum annual temperature of 0. 63, 1. 64 and 3. 34° C, the mean annual temperature was 0. 26, 0. 72 and 1. 46 ° C and maximum temperature parameter will be 0. 32, 0. 55 and 0. 81° C.

Azo dyes have different applications in industry. Several chemical and physicalmethods have been proposed in removing of these dyestuffs. Alternatively, biological treatment is recognized as economical and environmentally friendly method for decolorization of dyestuff wastewaters. In the current research the capacity of the removal of Remazol Black-B and Remazol Red-B by Streptomyces hygroscopicus PTCC1132 in static condition was investigated. An OA layout was constructed with four factors: temperature (28-35° C), pH (6-8), salt concentration (0. 5%-2%) and dye concentration (500-10000 mg/l) at four levels for the experimental design. The design and analysis of Taguchi experiments was performed by Qualitek-4 software. We showed that the Remazol Black-B decolorization can be significantly improved by Optimization of the factors involved in Remazol Black-B decolorization by S. hygroscopicus. The optimal conditions were pH 9, temperature 33oC, salt concentration 1% and dye concentration 5000 ppm. Under optimum conditions. Thus, this straine, under the achived effective condition az a result of exprements analysis i. e, temperature 33oC, pH=8, and salt concentration as 1% up to 100% of azo dyes(RR-B) with the density of (10000 ppm) will be removed aqueous medium. employing this type of bactria in biological treatment of wastwater with industrial dyes can be of great help in treatment and re-use wastewater.

Microplastics as emerging and unfamiliar contaminants have been considered by researchers during the last decades. These small particles and fragments, typically have a size less than 5 mm and could penetrate into the marine environments by different ways, threatening the environment and animal health. Therefore, in this study, according to the studies by different researchers, this pollutant is introduced and some of its effects are mentioned in marine environments. One impacts of microplastics on marine organisms, such as marine vertebrates and invertebrates, arise from direct ingestion of plastic fragmentS by the marine biota leading into internal injuries. They also can have negative effects on the distribution of certain species of marine organisms, which they oviposit on the surface of these contaminants. Chemical adsorption is the most important impact of microplastics in marine environments, which not only transfers pollution, but also increases environmental resistance of these contaminants. Recent research works on the effects of microplastics pollution in the marine environment emphesis that permanent and continous monitoring of these materials and discovery of the pollution hotspots is crucial in environmental issues.

The unavoidable requirement to avoid the undesirable consequences of tourism and to achieve optimal pattern of tourism development is land planning and ecological capability assessment. The purpose of this study was to identify and locate the appropriate ecotourism zones on the route of the Gheshlagh tourism in Sanandaj, Kurdistan, Iran. The research method was descriptive-analytic, library and field studies, as well as the use of GIS geographic information system. For this purpose, required layers of information including altitude, gradient, slope, vegetation and water resources were prepared. In the next step, variables were evaluated using the AHP model and experts’ opnion. Then, using spatial analyzers in the GIS environment, the outputs were derived from the reference maps, and the overlay of these maps in the GIS environment using the algebraic aggregation operator was the final output of the tourism spatial zonation. The results were calculated in five classes of utility and showed that about 20% of the region is suitable for development of tourism and about 20% of the region has the ability to develop moderately with ecological aspects. About 33% of the total area showed prohibited tourism development. The results of this research can be used as an indicator for the development of appropriate and optimal applications within the framework of economic projects in the region.