Mathematical Description of the Increase in Selectivity of an Anion-Exchange Membrane due to Its Modification with a Perfluorosulfonated Ionomer

Ion-exchange membranes (IEMs) are widely used in desalination, waste water treatment, food, energy production and other applications. There is a strong demand for cost-effective IEMs characterized by high selective transport of ions of a certain sign of charge. In this paper, we simulate the experimental results of V. Sarapulova et al. (IJMS 2021) on the modification of an inexpensive anion-exchange membrane (CJMA-7, Hefei Chemjoy Polymer Materials Co. Ltd., China) with a perfluorosulfonated ionomer (PFSI). The modification was made in several stages including keeping the membrane at a low temperature, applying a PFSI solution on its surface, and subsequent drying it at an elevated temperature. We apply the known microheterogeneous model with some new amendments to simulate each stage of the membrane modification. It has been shown that the PFSI film formed on the membrane-substrate does not affect significantly its properties due to the small thickness of the film (4 m) and similar properties of the film and substrate. The main effect is caused by the fact that PFSI material “clogs” the macropores of the CJMA-7 membrane, thereby blocking the transport of coions through the membrane. In this case, the membrane microporous gel phase, which has a high selectivity to counterions, remains the primary pathway for both counterions and coions. Due to the above modification of the CJMA-7 membrane, the coion (Na+) transport number in the membrane equilibrated with 1 M NaCl solution decreased from 0.11 to 0.03. Thus, the modified membrane becomes comparable in its transport characteristics with more expensive IEMs available on the market.

THE ROLE OF GIS IN ADDRESSING ENVIRONMENTAL, SOCIAL AND TOURISTIC CHALLENGES IN MOHAMMEDIA CITY, MOROCCO

During the last years, Morocco’s Environmental, Social and Touristic perspectives has improved significantly, but it remains one of the biggest challenges for Mohammedia city. The purpose of this study is to locate an optimal site for the construction of a new Waste Water Treatment Plant (WWTP) in order to help the environment, to select an appropriate site for the construction of a new School that will benefit the social needs of the city and to create a suitable tour plan of touristic sites for tourism. It was carried out by using Geographic Information System (GIS), Remote Sensing (RS), Global Positioning System (GPS) devices, Digital cameras and Multi- criteria Decision Analysis (MCDA).Throughout the process, the used data for both WWTP and School selection include the remote sensing data of multi spectral satellite imageries and the digital elevation model combined with vector data of land use (LU) layers, and for Tour creation the used data include collected photographs and GPS data from the site. According to MCDA, the results presents an optimal site with an area of 48283,02 m2 for a new WWTP, a suitable area with an area of 3200 m² for a new School and a city tour for tourists with a distance of 27 km.

A holistic overview on corn cob biochar: A mini-review

Corn cob is one of the agricultural waste materials subjected to improper burning, which creates pollution. It can be used for the production of green technologies for further applications. Carbonisation or slow pyrolysis could be promising alternative to burning. It has many applications, such as soil ameliorant, waste water treatment, carbon sequestration, composting, supercapacitor, fuel cell and biocomposites material. It motivated to investigate the suitability of corn cob as a potential material for biochar production and its application. The advanced form of analysis, such as thermogravimetric, scanning electron microscopy, surface area, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and Raman spectroscopy, is elaborated for in-depth knowledge of characteristics. The hypothesis is that if the available corn cob is used for biochar production, it will reduce the carbon dioxide (CO2) emission. On a global level, conversion of available corn cob into biochar is expected to reduce CO2 emission by 0.13 Gt per year. The reduction in CO2 emission also favours economy. If 1 tonne of biomass per year is converted into biochar, 0.82 tonnes of CO2 can be reduced per year and by considering the emission cost of Rs 1800 per tonne, the cost saving would be Rs 1476 per year. The presented mini-review article provides an outline of the state-of-art information on corn cob biochar and its novel application. It will be helpful to scientific domain to find new opportunities in biochar research and also the humanity will be benefitted due to reduction in greenhouse gases.

Integrated Water Balance and Water Quality Management Under Future Climate Change and Population Growth: A Case Study of Upper Litani Basin, Lebanon

The impacts of the growing population at Lebanon including Lebanese, Palestinian and Syrian refugees, associated with the changing climate parameters such that the precipitation are putting the Bekaa Valley’s water resources in a stymie situation. The water resources are under significant stress limiting the water availability and deteriorating the water quality at the Upper Litani River Basin (ULRB) within the Bekaa Valley region. These impacts are assessed by Water Evaluation And Planning model to assure the water balance and quality at baseline scenario in 2013, and future scenarios reaching 2095, serving by the Watershed Modeling System to get the flow throughout the Litani River’s ungauged zones. Moreover, a General Circulation Model is used to predict the future climate up to 2100 under several emissions scenarios which shows a critical situation at the high emission scenario where the precipitation will be reduced about 87 mm from 2013 to 2095. The aim of this research is to reduce the water pollution that limits the availability of usable water, and to minimize the gap between the demand and supply of water within the ULRB in order to maintain water resources sustainability, and preserves its quality, even after 80 years. In particular, this may be achieved by removing encroachments on the river, by adding waste water treatment plants, by reducing the amount of lost water in damaged water network, and by avoiding the overconsumption of groundwater.

Dissolved organic matter signatures in urban surface waters: spatio-temporal patterns and drivers

Advances in analytical chemistry have facilitated the characterization of dissolved organic matter (DOM), which has improved understanding of DOM sources and transformations in surface waters. For urban waters, however, where DOM diversity is likely high, the interpretation of DOM signatures is hampered by a lack of basic information. Here we explored the spatiotemporal variation of DOM composition in contrasting urban water bodies, based on spectrophometry and fluorometry, size-exclusion chromatography and ultrahigh-resolution mass spectrometry, to identify linkages between DOM signatures and potential drivers. The highly diverse DOM we observed distinguished lakes and ponds characterized by a high proportion of autochthonous DOM from rivers and streams with more allochthonous DOM. Seasonal variation was apparent in all types of water bodies, driven by the interaction between phenology and urban influences. Specifically, nutrient supply, the percentage of green space adjacent to the water bodies and point source pollution emerged as major urban drivers of DOM composition. Optical DOM properties also revealed the influence of effluents from waste water treatment plants, suggesting their use in water-quality assessment and monitoring. Furthermore, optical measurements inform about processes both within water bodies and in their surroundings, which could improve the assessment of ecosystem functioning and integrity.