Journal of Hydrosciences and Environment
Volume:2 Issue: 3, Feb 2018

Waste recycling is one of the favorable methods in waste management. Since huge amount of hazardous and non-hazardous wastes are produced in petrochemical industry, it is essential to characterize generated wastes and evaluate their recovery potential. Marun petrochemical complex (MPC) is located in Petrochemical Especial Economic Zone (PEEZ) on the northern coastline of the Persian Gulf. Waste management in MPC is quite complex due to diversity and their hazards to the environment and human health. In this study, different ypes of waste including processing and non-processing wastes were investigated. The recoverable wastes were estimated and effect of recycling on present waste management was assessed. Proper management of waste needs waste characterization including quantity, type, and composition. Therefore, questionnaires were used to collect data. During five units of production process, 6199 ton of solid, liquid, and hazardous wastes were generated in MPC annually. Classification of industrial establishments was made based on a comparative synthesis and analysis of recent nationwide surveys and studies pertaining to petrochemical waste anagement.  Results showed that the major parts of waste were catalysts, metallic materials, plastic barrel, 3.78% paper, wood, oil and glass respectively. In the view of physical properties, 80.1% of wastes were solid and remain was liquid. Serious problems were observed in the present management of these wastes such as in-situ dumping of wastes and low recycling. It is estimated that about 5000 ton of waste had optional of recovery. Therefore, waste recycling was recommended in MPC among other techniques of waste management.

The relationship between the accumulation of nitrate in the soil and its concentration in groundwater and in various plant systems is still not fully understood, but it indicates a high correlation between nitrate leaching and environmental and managerial factors. In this study, nitrate uptake by sugarcanes was simulated by the NLEAP model for different months during the simulation period and a new fertilization scenario was defined. According to the statistical analysis, the NLEAP model provided us with a good estimation in simulations and simulated nitrate volatilization and leaching more accurately. Also, it was revealed that N uptake rate was the highest in the scenario I1N3 due to lower water and higher N and that it was the lowest in the scenario I3N1 due to higher water and lower N.

There are many cases in open channel flows where the steady flow of water passes through a cluster of vertical cylinders. As a fluid flow is encountered with several obstacles, an overlapping of opposite forces is resulted by vortex shedding, and shear layers in the wake area takes place and transverse waves are formed along the width of the channel. The present study focused on this phenomenon and the effects of obstacle diameters on suspended sediment concentration based on laboratory tests in a rectangular flume. Wooden obstacles were used in an in-line arrangement only in the half part of a channel width divided by putting a plexi glass sheet. Firstly, in the similar condition of discharge, transverse and perpendicular obstacles distances, hydraulic conditions in maximum wave amplitude for different obstacle diameters were determined. Then, the  transportation of suspended sediment from upstream to downstream of obstacles and no-obstacle zone for wave modes 1 and 2 was compared to normal flow condition. Along with this, the suspended sediment concentration variations at downstream of obstacles zone were compared to no-obstacle zone. The results showed that transverse waves had a significant impact on reducing the suspended sediment concentration at downstream of obstacles zone rather than no obstacle zone and the maximum of reduced concentration percentages at downstream of obstacles zone versus the condition with no-obstacle zone, for wave modes 1 and 2 was about 11.2% and 8.3%, respectively. Therefore, wave mode 1 had more effect on the reduction of suspended sediment transportation than wave mode 2. In addition, an increase in obstacle diameters cause to increase the maximum values of the dimensionless displacement (A/H) by about 26% and 37% for wave modes 1 and 2, respectively. However, reduced concentration percentages at downstream of obstacles for wave mode 1 and 2 was decreased about 8%.

Supplying sea water with proper quality is the main concern for the desalination intake system, especially in RO desalination plant. The presented paper is focused on the seawater intake alternatives for desalination plants with the main aim to introduce the best selection at shores with a low slope. Supplying feed water and selecting the proper intake system at site locations with low costal gradient are very important due to providing required water quality and capacity, minimum environmental impact, geotechnical limitation's prolongation of intake route and increasing dredging volumes. By attention to the hydrography and topography conditions of each site, it is necessary to investigate all the intake alternatives. The various seawater intake methods are introduced in this paper and for a case study in Bandar Abbas city, according to their special site condition, six alternatives, independent pipeline, existing break water plus pipeline, piled jetty, existing breakwater plus piled jetty, beach wells and tidal sea water, are chosen to future investigation and selection the best lternative. These alternatives are evaluated and compared from the technical, construction, environmental and capital cost aspects, finally by grading and ranking of each alternative, the best intake method, existing break water plus pipeline, is the system that achieved higher scores.

Stable modelling in water resources management, on one hand, requires recognizing the relations between the different applications of water and their long-term results and on the other hand taking into account the current and future access to water resources and demands for them. In recent years, the basin of Kabudarahang plain has been identified as one of the critical groundwater areas in Hamedan province. In this plain, the groundwater level has been decreased remarkably due to lack of the proper water usage management. The purpose of this study is to provide a model to maximize the net benefit of farmers considering the stability of the groundwater reservoir. Since the effect of the groundwater discharge is accumulated over time, time is taken as an essential variable in solving water optimization problems. Accordingly, applying dynamic models such as the optimal control method is appropriate for this purpose. The optimal path for water extraction from groundwater resources can be determined using the optimal control model. In this model, the additional cost of water extraction due to the further exploitation has been considered as a constraint in the modeling process and the effect of the cost internalization are determined by the optimal path of the extraction and the price. Considering the optimal use of water and maximum welfare of the farmers, the results show that it will take about 38 years to increase the water level from 1716 meters to the optimal level of 1749 meters. During this period, the price of water will decrease from 1820 to 1180 Riyals per cubic meter and the annual harvest from the groundwater resources will reduce to the level of 1.7 million cubic meters. Therefore, the observation of the specified limit not only results in stable groundwater resources, but also leads to a sustainable agricultural development and the increase of farmers’ income in this area.

Tehran generates 7000 tons of municipal solid waste (MSW) daily with 70% of organic component which causes leachate and greenhouse gases generation. Anaerobic digestion (AD), as a natural process, can be a solution. On this basis, the aim of this research is to compare AD and sanitary landfilling as two scenarios environmentally and economically. So, capital cost, operational cost, environmental costs of greenhouse gases GHG emission, Benefits from GHG reduction and selling outputs has been considered and their time value has been calculated for the life span of 20 years. Although landfilling has much lower cost, AD has been selected as the best scenario due to engineering economy parameters. The benefit cost ratio and economical balance of landfilling and AD has been calculated 1.2 and 73.28 respectively. While, these figure are obtained -19.25 and 0.08 for landfilling, respectively. Finally, SWOT analysis has been done for the selected scenario.

Duckbill weirs do not have a straight crest in the direction perpendicular to the flow. The plan view of the weir consists of multiple and broken linear crests that increase its effective length. The advantages of this type of weirs are their higher discharge capacity, easy aeration as well as low fluctuations of water surface at the weir upstream. In this study, discharge coefficient of the duckbill weir is investigated numerically. Numerical modeling is carried out by Fluent v. 6.2. The simulated velocity and pressure field are coupled by using "Piso" method. Reynolds governing equations, turbulence k –ε model, and the Volume of Fluid (VOF) model are numerically solved to define pressure and velocity. Also a few equations are proposed to define the relationship of discharge coefficients with some dimensionless hydraulic Parameters. Results showed that as the height of weir is increased, the discharge coefficient increases and the value of discharge coefficient is constant after H/P = 0.3 and is fixed on 0.47. Also the increase in weir height has a significant effect on the increase in the duckbill weir on discharge coefficient, which is an important factor in designing these weirs. Equation 8, with error value of 0.01695, is presented as the best equation to estimate the discharge coefficient over duckbill weirs.