Qatar water challenges
Abstract Qatar has experienced rapid economic growth due to the discovery and production of fuel oil and natural gas (NG). The natural renewable water resources (rainfall and groundwater [GW]) are depleted; and are estimated as 71-m3/per year per capita in 2005. This is far below the water poverty line of 1,000-m3/yca. The GW withdrawal is excessive (compared to replenishment) and is used mainly for irrigation. A very small amount of GW is treated to become potable water and is distributed to consumers. The municipal potable water mainly contains (99%) desalted seawater (DW) and 1% GW. The consumption of DW and electric power (EP) is continuously rising due to the increase in both population and the standard of living. The population have been more than doubled from 2000 to 2010. The DW is produced in power plants generating both EP and DW, and is called Cogeneration Power Desalting Plants (CPDP). These CPDPs are using either: simple gas turbines (GT) cycle or GT combined with steam turbine (ST) to form a...
Use of DPSIR Framework to Analyze Water Resources in Qatar and Overview of Reverse Osmosis as an Environment Friendly Technology
Qatar and other countries of Gulf Cooperation Council are among the most water scarce countries in the world and are being characterized as “high‐water risk” countries by Water Resource Institute. Therefore, it is important to implement sustainable water resource management that encompass economic, societal, and environmental aspects. In this review article, the Driver‐Pressure‐State‐Impact‐Response framework was used to analyze the water resource system in Qatar in terms of drivers, pressures, change in state, impacts, and responses. It was noted that both economic and population growth together with unsustainable water consumption are major driving forces that are pressurizing the Qatar's water resources (desalinated seawater and renewable groundwater). Currently, desalination plants using Multi‐Stage Flash (MSF) techniques are predominantly being used to meet the rising water demands. However, widespread use of MSF techniques poses several environmental and economic impacts. Therefore, in addition to other management and corrective measures, reverse osmosis (RO) technique has also been suggested to be utilized in desalination industry as a “response” to mitigate those impacts. Since, the performance of RO is mainly affected by biofouling and mineral scaling, the paper also highlights the recent materials (polymers and nano‐materials) used to tackle these problems. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13081, 2019
Analysis of the stress wave effect during coal breakage by a high-pressure abrasive air jet
In view of the defects of borehole collapse, inhibition of gas desorption and migration of gas existing in hydraulic fracturing and other hydraulic permeability–increasing measures for soft coal seams with low-permeability technology is proposed for coal breakage by a high-pressure abrasive gas jet for relieving pressure and increasing permeability. The comparative analysis of gas jet flow field structure between convergent nozzle and Laval nozzle has been given by numerical simulation. For Laval nozzle, the expansion wave and compression wave alternate and move forward steadily in gas jet and vanish when potential core length reaches maximum. So, the Laval nozzle can form more stable flow filed structure of gas jet and avoid shock wave in gas jet. Furthermore, a high-speed camera is adopted to analyze the jet structure and verify the conclusion of numerical simulation. Based on thermodynamic theory, this article calculates and analyzes the critical local sound velocity and pressure generated from the stress wave during the process of coal breakage by the gas jet. Furthermore, experimental coal breakage by a high-pressure abrasive gas jet is carried out. The high-pressure abrasive gas jet impacts the coal body as a quasi-static load and a dynamic load and forms corrosion pits on the surface of the coal body. Penetrating cracks are formed within the coal in the pattern of the loaded stress wave which leads to coal breakage. The effects of porosity and permeability on the propagation of the stress wave in coal are analyzed by establishing the dispersion equation for the spread of the stress wave in coal. The results show that porosity has a significant effect on wave velocity and that the attenuation of the stress wave is intensified with an increase in porosity. Moreover, the stress wave attenuation is more obvious at high frequency. The effect of permeability on the wave velocity is not significant at low frequencies. In contrast, at high frequency and relatively low permeability, the wave velocity increases with the permeability, and the attenuation of the wave velocity initially increases and then decreases. When the permeability is greater than 10−11 m2, the wave velocity is not affected by the permeability. However, the stress wave is not attenuated.