35 research outputs found
A case study of Pb-scaling in a geothermal project in the West Netherlands Basin
No full textThis research was done in the framework of the RVO project on Development of a well impairment model for predicting geothermal clogging (DIMOPREC) .The importance of developing new energy sources with lower carbon emissions than conventional hydrocarbon based energy sources has been globally recognized (Andrews-Speed, 2016). Geothermal energy is a lower carbon energy source, which can be used for both electricity production and for direct heat use (Fridleifsson, 2001).However, radioactive mineral scaling can accumulate in filters and tubing of the geothermal facilities, which can be an operational hurdle as this scale needs to be removed with necessary caution. The problem is not only the riskiness of being exposed to radioactive elements, but also the rise in pressure caused by scale accumulation. This occurs at the filters resulting in more process stops. Another problem with the scaling is that it causes increasing injection pressure. Since there is a regulatory limit to this pressure, an increase in injectivity is not preferable. Here, a case of a low-enthalpy geothermal project is discussed where very limited radioactive galena, PbS, is found.This geothermal system is modelled in the geochemical software package PHREEQC. The PHREEQC model shows that a fraction (78 wt.%) of the collected galena is produced in solid phase from the reservoir, and a smaller fraction (22 wt.%) is formed after the heat exchanger. Gamma ray logs analyses and sedimentation history are presented to find potential sources of Pb and S ions. With the geological history and literature study it is found that the radioactive Pb could be originated from the Zechstein and Rotliegend where it attaches strong to the Copper shale formations. Scale and water analysis show that most of the captured galena is transported in a solid phase into the geothermal facility.In the second part we discuss the development of a SKID for scaling determination during geothermal production. It is proposed to design a new SKID with additional measurement and monitoring options, which is able to provide the requested input parameters for the PFREEQC model. Requested data acquisition for long term monitoring includes fluid pressure, flowrate, temperature and pH values. The mobile function makes it possible to sample at several surface locations along the line of the geothermal facility. The obtained and stored data can be analyzed and compared to other locations in order to find out whether or not the brine and its composition change, and if so, how it changesIn order to reduce the amount of radioactive PbS in the filters of the geothermal system, it could be considered to acidify the brine to a level where the minerals are dissolved. In addition, increasing the facility pressure and/or increasing the minimum brine temperature after the heat exchanger, could reduce the amount of galena precipitation captured in the filters of the geothermal facility.Applied Earth Science
Indentifying glacial features with sentinel-2 data
No full textThe Tibetan Plateau is a vast elevated plateau in Central and East Asia. It contains thousands of glaciers and other geographical features. Through this area rivers like the Brahmaputra is flowing and making a basin providing about millions of people a home. The last years global warming has been a focus of public and scientific debate. Not knowing what to expect and what the changes are result in ruling uncertainties which are of major concern because it could cause serious implications for water resources. During this study the area located in the Upper Brahmaputra in the South-East of the Tibetan Plateau called the Yiong Zangbu catchment will be investigated. To understand what glacial changed have occurred in the past few years data from different years were collected, processed and compared. The used datasets are ASTER GDEM, HydroSHEDS, GLIMS glacier mask and Sentinel-2 . Sentinel-2 data has been processed and different images are made like true colour and false colour images. Next to that a combination of datasets are used to see whether there is an accuracy issue and to understand what kind of features can be found on which height and what spectral reflectance belongs to it. After processing all the data of two following years differences can be seen. There are lakes that are frozen out within three months. Also glaciers which expanded downwards the hills. This can be a result of strong winters. On the higher parts there was more precipitation, which is helpful while remaining the current glaciers. <br/
Enhanced Cadmium Removal by Raw Argan Shell Adsorbent: Experimental and Theoretical Investigations for Ecological Applications
No full textThe removal of cadmium ions (Cd2+) using raw argan shells (ArS) was optimized through experimental and theoretical studies. Adsorption experiments revealed optimal conditions at an adsorbent dose of 3.5 g, an initial Cd2+ concentration of 20 mg·L−1, and a pH of 8, achieving a maximum sorption capacity of 3.92 mg·g−1. The kinetic analysis showed that the adsorption followed a pseudo-second-order model (R2 = 0.98), and the Langmuir isotherm model predicted a maximum adsorption capacity of 4 mg·g−1. Thermodynamic analysis indicated an endothermic adsorption process, with ΔG° shifting from positive to negative as temperature increased, confirming that adsorption is favored at higher temperatures. Desorption studies demonstrated that HCl was the most effective eluting agent, achieving a desorption efficiency of 90.02%, followed by HNO3 (76.65%) and CH3COOH (71.59%). The varying desorption efficiencies were attributed to differences in acid strength and ionic interactions with Cd2+. This study demonstrates the potential of raw argan shells as an efficient, reusable, and sustainable biosorbent for cadmium removal, offering a promising solution for water treatment and environmental remediation
Constructed Wetland as a Low-Energy Technique for Wastewater Treatment – Seasonal Impact, Performance and Phytomanagement
No full textThis work aims to study the seasonal impact on pollutant removal efficiency of constructed wetland (CW) units which treat domestic wastewater in the region of Rabat, Morocco. In this context, four vertical flow-constructed wetlands (VFCWs) were investigated for one year. Each CW unit has a surface area of 1m² and a depth of 60 cm. The difference between the units is the vegetation. The experiments are conducted on a laboratory scale and outdoors, to investigate also the direct effect of the climate. The purpose is to investigate the CWs performances with two different plant species (Phragmites Australis and Arundo Donax) and plant arrangements (mono-culture and poly-cultures). Since the region of Rabat has a semi-arid climate, plants behave during seasonal changes was explored. The elimination of organic matters showed a seasonal variation in the CW systems, with higher rates during the hot season and lower rates during the cold ones. Planted systems outperformed the unplanted system and the polyculture system was the most effective, reaching removal rates of 99.47%, 99.58%, and 85.64%, for, COD, BOD5, and TSS in the summer season where the temperature reaches its maximum promoting plant growth as well as microbial activity. Anyhow, results showed that the VFCWs used in this study are a successful technology for the region that is cost-effective and requires low energy
Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic) Acid in Hydrochloric Acid Solution
No full textTafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic) acid (ATMP) for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to . It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.</jats:p
Introducing Project-Based Climate Education in Moroccan Universities via a New Air Quality Monitoring Network in Rabat
No full textMorocco’s economy has recently seen an unprecedented growth, which made the country emerge into the 5th strongest economy of the African continent. As other countries at the same stage of development, Morocco is also undergoing rapid urbanization, which results in increased anthropogenic air-pollution levels. The geographical location of the country makes it vulnerable to both short and longterm impacts of climate change. Despite the elevated risk and vulnerability, the current air pollution and climate change monitoring strategy of the country needs improvement. The present paper introduces a novel strategy to improve the air quality monitoring system in the capital combined with developing a project-based climate education curriculum, and promises to raise public awareness to the risks related to air pollution and climate change. The sustainability of the project is guaranteed by the low cost of instruments and the educational aspect which ensures that future experts are well-trained for the maintenance of the system that we propose to install
Optimization of Organic Micropollutant Adsorption onto Granular Activated Carbon Using Response Surface Methodology
No full textWater pollution from pharmaceutical and textile industries urgently requires effective treatment solutions due to environmental and health risks. Effective treatment methods are desperately needed for water pollution from the textile and pharmaceutical industries because of the dangers to the environment and human health. To treat these micropollutants, the optimized granular activated carbon (OGAC) produced from olive fruit stones was utilized as an adsorbent in this study. The central composite design (CCD) of response surface methodology (RSM) was statistically used to optimize the operating factors for rhodamine B (RhB) and thiamphenicol (THI) removal efficiency on the optimized granular activated carbon. This study evaluated the influence of factors such as the solution’s pH, initial RhB and THI concentration, and OGAC dose, along with their interactions to model outcomes and determined optimal adsorption conditions on OGAC. The adsorption kinetic data will be analyzed using the intra-particle diffusion, pseudo-second-order, and pseudo-first-order models. Equilibrium data will be analyzed using the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The adsorption thermodynamics of the various systems under investigation will also be examined. Finally, a study on OGAC regeneration has been conducted. Results showed that THI and RhB removal is primarily influenced by pH, initial pollutant concentration, and dose. RSM indicated the optimal adsorption parameters for THI and RhB on OGAC as pH = 5.7, an initial concentration of C0 = 2.5 mg/L, and a dose of 6 g/L. The kinetic study revealed that THI and RhB retention on OGAC generally follows a pseudo-second-order kinetic model, indicating chemisorption as the primary mechanism controlling adsorption. The adsorption isotherm data analysis showed that chemisorption has a significant role in the THI and RhB adsorption process on OGAC. Furthermore, thermodynamic parameters suggest that THI adsorption on OGAC is exothermic, while RhB adsorption is endothermic. Activated carbon regeneration tests demonstrated its cost-effectiveness, and activated carbon was successfully regenerated over three cycles, achieving efficiencies of 62.39% for RhB and 59.6% for THI. These results demonstrate that the studied OGAC is an effective adsorbent for THI and RhB removal
Introducing Project-Based Climate Education in Moroccan Universities via a New Air Quality Monitoring Network in Rabat
No full textMorocco’s economy has recently seen an unprecedented growth, which made the country emerge into the 5th strongest economy of the African continent. As other countries at the same stage of development, Morocco is also undergoing rapid urbanization, which results in increased anthropogenic air-pollution levels. The geographical location of the country makes it vulnerable to both short and longterm impacts of climate change. Despite the elevated risk and vulnerability, the current air pollution and climate change monitoring strategy of the country needs improvement. The present paper introduces a novel strategy to improve the air quality monitoring system in the capital combined with developing a project-based climate education curriculum, and promises to raise public awareness to the risks related to air pollution and climate change. The sustainability of the project is guaranteed by the low cost of instruments and the educational aspect which ensures that future experts are well-trained for the maintenance of the system that we propose to install
Induced mutagenesis for improving water stress tolerance in durum wheat (Triticumturgidum L. subsp. durum)
No full textOver the Water deficit is considered to be one of the most important limiting factors for crop productivity worldwide. Thus, it is important to use water resources more efficiently. One of the ways to conserve water and respond to the climate change is by using appropriate crop species and cultivars, notably which have low requirements for water.Chemical mutagens have contributed immensely to the development of a wide range of genetic variability and the improvement of several crop plants, including durum wheat. This study has the aim of understanding the effect of water stress on some morpho-physiological parameters and identifying tolerant lines to water stress from an EMS-mutated population in durum wheat. The results, under moderate (T1) and severe (T2) conditions of water stress,show the positive effect of mutagenesis on the population resulting in tolerantmutated linesto water deficit. Compared to the non-mutated, 32.15% of lines have a higher specific leaf weight; 57.14% of lines have a better ability to maintain a high water content and 75% of all lines demonstrate a very high intensity of chlorophyll fluorescence .In sum, this study has revealed the improvement of water stress tolerance in some induced durum wheat mutants
Study of the Electronic, Optical, and Photovoltaic Properties of Lead-Free Double Perovskite Cs₂AgBiCl₆ Through DFT Calculations
No full textInternational audienc
