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Oil biodegradation in sea water
, Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 25, Issue 1 , 2001 , Pages 87-92 ; 03601307 (ISSN) ; Vossoughi, M ; Sharif University of Technology
2001
Abstract
Biodegradation of petroleum hydrocarbons in salt medium (SM) containing sea water by Pseudomanas sp. was investigated. Different oil hydrocarbons such as n-decane, benzene, naphthalene, paraffin, paraffin + vaseline, paraffin + kerosene, and fuel oil were used as carbon sources. Cell growth (OD) and COD were measured for evaluation of oil biodegradability. The effect of inorganic and organic nitrogen sources on COD removal revealed a 95% and 75% reduction of COD for inorganic and organic nitrogen sources, respectively
An Efficient Simulation-Optimization Model for Coastal Groundwater Management
, Ph.D. Dissertation Sharif University of Technology ; Ataie-Ashtiani, Behzad (Supervisor)
Abstract
Groundwater in coastal aquifers is one of the essential resources of freshwater in coastal regions, where are heavily populated or industrialized areas, and have critical ecosystems.The management of these resources is a priority to preserve groundwater from serious natural and human-induced threats such as salinization caused by seawater intrusion. The combined simulation-optimization techniques can be used for this purpose in determining optimal planning and management strategies. The implementation of such techniques for complex real-world and large -scale problems has major difficulties in terms of both computational efficiency (solution quality and required computational time) and...
Effect of Sea Level Rise and Aquifer Characteristics on Seawater Intrusion in Coastal Aquifers
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
Approximately, 60 percent of the world's populations are living at the distance of 60 kilometers of the coasts. In coastal zones, coastal aquifers are the most important resources of the available freshwater while expected that the short-term or long-term impacts of the climate changes threat such aquifers. In general, it is predicted that climate changes e.g. sea-level rise (SLR) cause to increase seawater intrusion (SWI) in the coastal aquifers. In this study, both continental and island coastal aquifers are considered. The objective of this research is the investigation of SWI behavior occurred in the coastal aquifers due to climatic change parameters and aquifer properties. For...
Conceptual models for Seawater Intrusion Simulation
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
Ground water resources are the main source of water supply in many regions. During last decades ground water quality has been deteriorated due to many sources of contamination. Seawater intrusion in coastal aquifers is one of these sources. With development of different numerical models, simulation of seawater intrusion in coastal and island aquifers has been used greatly in analyzing the condition of these aquifers. The first step in performing a numerical modeling is determination of a suitable conceptual model. Considering the complexity of a real problem, a proper conceptual model should show the true condition of the problem as well as lead to a cost and time effective simulation. In...
Cathodic Protection of Concrete by Zinc Sacrificial Anode in Persian Gulf Sea Water
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Many of the major structure over coastal waters in the Kish Island due to the aggressive condition are showing signs of reinforcement corrosion. Recent advances in the development of anodes make it practical to use zinc galvanic cathodic protection to protect this structure in this area. Five anode systems were tested on several samples as, (1) zinc metal spray applied by arc-spraying on the concrete, (2) a zinc foil with conductive adhesive backing, (3) a system of zinc mesh and grout jacket, (4) a system of zinc mesh and compression panels, and (5) a bulk zinc. These anodes are set up to comparison the effects of potential and current over the zinc galvanic cathodic protection during 4...
Uncertainty Analysis and Inverse Modeling of Seawater Intrusion in Coastal Aquifers
, Ph.D. Dissertation Sharif University of Technology ; Ataei Ashtiani, Behzad (Supervisor)
Abstract
Groundwater is the primary source of freshwater in many coastal areas and small islands around the world. The most important hazard to groundwater quality in coastal aquifers is seawater intrusion (SWI) resulting from over pumping, prolonged drought conditions and sea level rise due to climate change impacts. Numerical models of SWI are an important tool in the management of coastal aquifers. However, numerical modeling of SWI is one of the most challenging problems in groundwater hydrology. One of the reasons for the challenging nature of SWI numerical modeling is the relatively large level of uncertainty associated with the estimation of the model input parameters. This study focused on...
Obtaining a Semi-analytical Solution for Contaminant Transport in Coastal Aquifers: Fourier-galerkin Method
, M.Sc. Thesis Sharif University of Technology ; Ataie-Ashtiani, Behzad (Supervisor) ; Jamali, Mirmosaddegh (Co-Advisor)
Abstract
Existing closed form solutions of contaminant transport problems are limited by the mathematically convenient assumption of uniform flow. These solutions cannot be applied for coastal aquifers where seawater intrusion induces a variable velocity field. The Fourier series method is adapted to obtain a semi-analytical solution for contaminant transport in confined coastal aquifer in which the saltwater wedge is in equilibrium with a freshwater discharge flow. The developed method can be applied for different scenarios of contamination. Two scenarios dealing with, respectively, contaminant leakage from a source at the aquifer top surface and aquifer contamination from the landward boundary are...
Numerical Models with Discrete Approach for Simulating Seawater Intrusion in Fractured and Karst Coastal Aquifers
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
In many countries of the world, especially dry and semi-arid areas, coastal aquifers are used to provide fresh water. Many of these areas have also become urbanaized, which has made the need for freshwater more important. Seawater Intrusion (SWI) is the greatest limitation that influences the exploitation of groundwater in coastal aquifers, where with SWI, the amount of freshwater supply and other existing pumping wells are not used. The present study attempts to model SWI in karst and fractured coastal aquifers. For this purpose, two models with Discrete Fracture/Conduit Network approach in Fortran and also in COMSOL Multiphysics software have been developed to study the density-variable...
Three Dimensional Numerical Simulation of Fresh Water Lens in Small Islands (Case Study: Kish Island)
, M.Sc. Thesis Sharif University of Technology ; Ataei Ashtiani, Behzad (Supervisor)
Abstract
Sensitive ecosystem and scarcity of freshwater are the main characteristics of small islands. These islands have small catchments and usually lack tangible surface water resources. As a result these islands are dependent almost entirely on groundwater. Groundwater on small islands usually occurs in the form of a freshwater lens floating on the more dense saline water. The freshwater lens is highly sensitive to various stresses such as drought, pumping, sea tide, etc. Due to the importance of freshwater lens in islands, proper and optimal use of this vital resource should be studied. Kish island`s freshwater lens was three dimensionally simulated using the numerical model SUTRA. The aim was...
Environmental Impacts Assessment of Desalination Plants Operating in the kish Island and Outlines Improvements
, M.Sc. Thesis Sharif University of Technology ; Hashemian, S.Jamal (Supervisor)
Abstract
The subject of this thesis to assessment environmental impacts of active desalination plants in Kish Island, which explains the problems derived from concentrate discharges in to the sea, sewage network, absorbing wells and ground surface.
It also studies its impacts on land and marine ecosystem and underground aquifers that are strategic resources in Kish Island. In addition, the environmental studies done in other countries, the existing regulations and by laws in the field of environmental impacts of desalination plants and concentrate discharges are re-mentioned. Concentrates contain chemicals, which are used in pre-filtration of MED and Ro systems, which are dangerous for marine...
It also studies its impacts on land and marine ecosystem and underground aquifers that are strategic resources in Kish Island. In addition, the environmental studies done in other countries, the existing regulations and by laws in the field of environmental impacts of desalination plants and concentrate discharges are re-mentioned. Concentrates contain chemicals, which are used in pre-filtration of MED and Ro systems, which are dangerous for marine...
Gorgan Bay Water Salinity Modeling under the Scenario of Water Transfer from Caspian Sea by Pipeline
, M.Sc. Thesis Sharif University of Technology ; Raie, Mohamad (Supervisor)
Abstract
Gorgan Bay and Miankaleh Wetland have been exposed to various environmental risks in the past years due to the decrease in the Caspian water level and the subsequent decrease in the water level of these water bodies. 2 channels, Chapgoli and Ashuradeh, are the only ways connecting the Gulf with the Caspian Sea. If the water level of the Caspian Sea and the Gulf continue to decrease, these 2 channels will be completely blocked and the connection between the Gulf and the sea will be completely closed. Due to the low depth of the bay and high evaporation on this water body, the blockage of these 2 channels will eventually lead to drying up of the bay or changing the flora and fauna of the area....
Investigation of Optical-Electrochemical Properties of Tungsten/Tungsten Trioxide Nanosheets with Layered Double Hydroxides Catalysts for Seawater Spilitting
, M.Sc. Thesis Sharif University of Technology ; Simuchi, Abdolreza (Supervisor) ; Mushfeq, Alireza (Supervisor)
Abstract
Decomposition of seawater with the help of sunlight is one of the most promising ways to produce hydrogen as a clean and acceptable fuel in the future. Tungsten photoelectrode is a suitable option for seawater decomposition due to its medium bandwidth, excellent load transfer properties, good chemical stability in acidic and neutral environments, abundance and cost-effectiveness. On the other hand, intermediate metal catalysts (Fe, Ni, Co) are very important due to their abundance in the earth's crust and their stability in alkaline and neutral environments instead of oxides of precious metals (RuO2, IrO2). In this study, tungsten plate (WO3) nanostructures were grown on the surface of a...
Quantifying the Relative Share of Factors in Drying Gorgan Bay and Miankaleh Peninsula by Studying Long-Term Water Balance
, M.Sc. Thesis Sharif University of Technology ; Danesh Yazdi, Mohammad (Supervisor)
Abstract
GB and Miankale Wetland are one of the most valuable water areas in the country from an ecological perspective, providing a habitat for a wide range of aquatic species and birds as well as providing a platform for fishing and tourism for locals. Recently, this wildlife refuge has experienced a crisis of reduced water levels and degraded water quality. Past studies have examined how fluctuations in the Caspian Sea water level affect GB's water quantity and quality. Due to the critical situation of Gorgan Bay, other factors affecting its water balance and upstream basin need to be examined, such as ground water flow and consumption, precipitation, and evaporation, and how they all affect the...
Experimental investigation of inorganic scale deposition during smart water injection - A formation damage point of view
, Article IOR NORWAY 2017 - 19th European Symposium on Improved Oil Recovery: Sustainable IOR in a Low Oil Price World, 24 April 2017 through 27 April 2017 ; 2017 ; 9789462822092 (ISBN) ; Mokhtari, R ; Ayatollahi, S ; Riahi, S ; Malekzade, E ; Sharif University of Technology
Abstract
Smart water injection is determined as an effective EOR process to change the wettability and interfacial tension for better micro/macro sweep efficiencies. This water contains reactive ions such as Mg ∧(2+), Ca ∧(2+) and SO-4 ∧(2-) which can act as potential determining ions and change the surface charge of calcite rocks. One of the major concerns in the execution of an effective waterflood, especially in tight carbonate reservoirs, is the incompatibility between the formation brine and the injecting water. This research work aims to investigate the most important challenge of waterflooding process related to the possible formation damage because of inorganic scale deposition during...
Oppositely charged MXene fibers as a highly efficient osmotic power generator from sea and river water
, Article Journal of Materials Chemistry A ; Volume 10, Issue 46 , 2022 , Pages 24915-24926 ; 20507488 (ISSN) ; Esfandiar, A ; Sharif University of Technology
Royal Society of Chemistry
2022
Abstract
Ion-exchange membrane-based reverse electrodialysis (RED) shows great potential for harvesting osmotic energy from seawater and converting it to electricity. However, their low energy conversion efficiency and huge ionic resistance hinder their application on large scales. The implementation of nanofluidic channels in RED devices can significantly improve the performance of osmotic power generators due to their selective and fast ion transport. However, technical challenges in scalable processing at the nanoscale and ion-selective membranes restrict their development in economically viable generators. Here, we report fibrous-based channels as positively and negatively charged MXene fibers...
Impacts of Water Level Rise and Fall of a Hypersaline Lake on Seawater Intrusion: Case of Lake Urmia, Iran
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
Lake Urmia located in the NW of Iran, has lost 96 percent of its volume in 20 years and become a national crisis. During this shrinkage, the lake level has fallen by 8 m, and its concentration has increased up to 380 g/l. Regarding the vast area Lake Urmia basin is covered, the hydrological characteristics of the basin varies a lot, which affects the aquifers response to the seawater intrusion. In order to study the seawater intrusion in the lake’s aquifer, 18 cases with different hydraulic gradients, hydraulic conductivities and bathymetries were defined. All of these cases were run under three different scenarios in sequence. First, steady state scenario is preformed, then the lake level...
Performance of sea water dilution on the surface free energies of the crude oils in water-flooded carbonate rock
, Article Journal of Adhesion Science and Technology ; 2017 , Pages 1-10 ; 01694243 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Abstract
Although several investigations have studied the low-salinity water injection (LSWI) performance during the past decades, the effect of crude oil type on the interfacial tension (IFT) and wettability alteration is still in dark. In this regard, this study is aimed to obtain the thermodynamic energies including adhesion, cohesion and spreading coefficient during LSWI. To achieve this goal, IFT and static contact angle values of three different crude oils (i.e. light, medium and heavy) are measured as a function of sea water salinity. The obtained results revealed that the dilution of sea water can change the wettability of reservoir rock from oil wet state towards water wet state, while crude...
Performance of sea water dilution on the surface free energies of the crude oils in water-flooded carbonate rock
, Article Journal of Adhesion Science and Technology ; Volume 32, Issue 12 , 2018 , Pages 1359-1368 ; 01694243 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
Although several investigations have studied the low-salinity water injection (LSWI) performance during the past decades, the effect of crude oil type on the interfacial tension (IFT) and wettability alteration is still in dark. In this regard, this study is aimed to obtain the thermodynamic energies including adhesion, cohesion and spreading coefficient during LSWI. To achieve this goal, IFT and static contact angle values of three different crude oils (i.e. light, medium and heavy) are measured as a function of sea water salinity. The obtained results revealed that the dilution of sea water can change the wettability of reservoir rock from oil wet state towards water wet state, while crude...
Selective withdrawal optimization in a multipurpose water use reservoir
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 10 , 2019 , Pages 5559-5568 ; 17351472 (ISSN) ; Moridi, A ; Mirbagheri, A ; Abbaspour, M ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2019
Abstract
Dam construction in arid and semiarid regions is generally related to the risk of increased salinity, due to water passage in contact with salty formations. Hence, it is important to take reservoir thermal and salinity stratification into account in operational rules. In the present study, a simulation–optimization model was developed to determine the amount of water release from various outlets to discharge the brine from hypolimnion layer considering the downstream water quality limitations. The most appropriate time, rate, and concentration to release brine were determined based on water consumption conditions and downstream water demand and river ecology characteristics. The proposed...
Implementing a superhydrophobic substrate in immersed solvent–supported microextraction as a novel strategy for determination of organic pollutants in water samples
, Article Ecotoxicology and Environmental Safety ; Volume 163 , 2018 , Pages 104-110 ; 01476513 (ISSN) ; Asem Yousefi, A ; Bagheri, H ; Sharif University of Technology
Academic Press
2018
Abstract
In this research, a new approach for extraction and determination of polycyclic aromatic hydrocarbons from sea and rain water samples was developed by implementing a superhydrophobic substrate and consuming the least amount of solvent. This version of solvent–supported microextraction enabled us to perform the procedure in the immersion mode with the slightest troubles arising from water leakage into the gas chromatography. The superhydrophobic property leads to the fixation of extracting solvent on the substrate surface during water sampling. To prepare a superhydrophobic substrate, a piece of melamine foam was coated by tannic acid and silica nanoparticles using methyltrimethoxysilane and...