Abstract
The current research project focuses on the feasibility of recycling and reusing utilized osmosis membranes from the Beni Saf water seawater desalination station in the province of Ain Temouchent. The composite Reverse Osmosis (RO) membrane, which is referenced BW30-400-FR and manufactured by Dow Filmtec TM, is used for all the tests. Three solvents are tested: potassium permanganate (KMnO4), sodium hydroxide (NaOH), hydrogen peroxide (H2O2), and the mixture of NaOH with KMnO4 for the degradation of the active layer of the RO membrane. A frontal filtration of wastewater using these modified membranes was carried out. An analysis of the physicochemical properties of the filtrate was performed using a spectrophotometer. The results of the frontal filtration performed under perpendicular pressure using a filtration ramp show that the membranes immersed in the NaOH and KMnO4 mixture for 24 hours produced a higher hydraulic flux compared to those immersed in NaOH and H2O2. At the end of the proposed treatment, the samples are analyzed by scanning electron microscopy (SEM) in addition to analyzing the clogging powder by EDX. The obtained results show the effectiveness of the proposed treatment for the degradation of the active layer in order to transform it into microfiltration and/or ultrafiltration.
Key Words
membrane; membrane filtration; pollutants; reverse osmosis; wastewater treatment
Address
Khadidja Benyahia: Department of Process and Materials Engineering, National Polytechnic School, Oran, Algeria/ Physics-Chemistry Laboratory of Catalysis and Environment Materials, USTO, Algeria
Mouhssin Khiari and Mourad Berrabah: Department of Process and Materials Engineering, National Polytechnic School, Oran, Algeria
Abstract
Asymmetric flat sheet poly(vinylidene fluoride) (PVDF) membranes were fabricated using the phase inversion technique, employing four distinct solvents with varying solubility power: N, N-dimethylacetamide (DMAc), N, N- dimethylformamide (DMF), Dimethyl sulfoxide (DMSO), and N-Methyl-2-pyrrolidone (NMP). The influence of these solvents on the crystalline properties of the polymers was investigated using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) to elucidate their role in PVDF polymorphism during membrane formation. Our findings revealed significant variations in membrane crystalline phase due to the dissolution of PVDF in different solvents, with α-polymerization predominant in membranes cast with NMP and DMSO, while DMF and DMAc solvents favored β-type polymerization. Further, various additives including PEG-400, TiO2, LiCl, LiBr, acetone, ethanol, propanol, and water were employed to evaluate their impact on membrane morphology and properties. Scanning electron microscopy (SEM) and Ultimate testing machine (UTM) were utilized to analyze membrane morphology, while the tensile strength, contact angle, pore size, and porosity were estimated using the sessile drop method, imageJ, and gravimetric method, respectively. Our results demonstrated that all additives exerted influence on membrane morphology and properties depending on their characteristics and interactions with solvents and polymers. Notably, acetone, being volatile, facilitated the formation of a thin PVDF layer on the membrane surface, resulting in a reduced average pore size (0.18µm). Conversely, LiCl and LiBr acted as pore-forming additives, yielding membranes with distinct pore characteristics and porosity. Moreover, water as a non-solvent additive induced pregelation during the nonsolvent-induced phase separation (NIPS) process, thereby promoting pore formation (53% porosity) and enhancing membrane hydrophobicity (104° contact angle). To evaluate the quality of synthesized membranes, permeate flux ranging from 16.2 L/m2.hr to 27.9 L/m2.hr with a salt rejection rate of 98 %, was evaluated using Vacuum Membrane Distillation (VMD).
Address
Meenakshi Yadav, Sushant Upadhyaya and Kailash Singh: Department of Chemical Engineering, Malaviya National Institute of Technology Jaipur-302017, India
Abstract
The following paper outlines the strange juncture of scientific principles and artistic expression by showing how studies of water force and dynamics of pipes can influence or inspire contemporary fine art. The radial force exerted by the internal viscous fluid is calculated using the Navier–Stokes equation. This work ascertains the fluid mechanics and structural behavior that pipes undergo due to water forces and can be translated into the medium of painting and sculpture. This paper will analyze the dynamic interactions between water and pipes reinforced with nanoparticles, while at the same time searching for new forms of representation concerning motion, flux, and structure within art. Results indicate that an increase in nanoparticle content leads to a reduction in transient deflection. The work includes case studies of artworks that incorporate these scientific aspects and also provides a theoretical framework to understand how technical phenomena can be transformed into visual and conceptual forms in art.
Key Words
dynamics; fine art; fluid and flow; pipes; water force
Address
Luchen Sun, A.: School of Foreign Languages & Physical Education, Shenyang Pharmaceutical University, Liaoning Province,110016, China
Zamani Nouri: Department of Civil Engineering, Shar-e-Qods Branch, Islamic Azad University, Tehran, Iran
A. Yvaz: World-class research center "Advanced Digital Technologies", State Marine Technical University, Saint Petersburg, 190121 Russia
Abstract
Paldang Lake is a reservoir that formed behind Paldang Dam on the Han River, and it is the largest water resource in South Korea. Thus, managing its water quality is important to secure a supply of clean drinking water. However, the amount of nonbiodegradable organic matter in Paldang Lake has been increasing. In this study, the objective was to quantitatively and qualitatively evaluate the levels of nonbiodegradable organic matter at different points along two rivers flowing into the lake. Multiple water quality indicators were measured including the total organic carbon (TOC), dissolved organic carbon (DOC), and refractory TOC and refractory DOC. The results were used to clarify how pollution patterns in the two watersheds have affected the water quality of Paldang Lake, and they are expected to help guide efforts to protect and manage this resource.
Key Words
DOC; regional analysis; R-DOC; R-TOC; stream; TOC
Address
Bogyeon Lee, Chaewon Kang and Kyungik Gil: Department of Civil Engineering, Seoul National University of Science and Technology, 232, Gongneung-ro, Nowon-gu, Seoul, South Korea, 01811
Abstract
It has been reported that rare earth elements (REEs) are considerably present in coal ash. In this study, an ecofriendly sequential extraction method was developed for the effective REE recovery from coal ash and leaching wastewaters. Citrate, a weak and environmentally benign solvent that replaces acetate employed in the existing sequential extraction methods (e.g., European community bureau of reference (BCR) and Tessier methods), was found to be highly effective in leaching REEs from coal ash. Microwave-assisted thermal digestion improved the REE extraction efficiency even further, with an overall leaching rate of 70%, which is 2.54 and 3.76 times higher than the values achieved by the conventional BCR and Tessier methods, respectively. It was also confirmed that the majority of REEs was strongly bound to CaO, Al2O3, Fe2O3, and P2O5, not to SiO2. The sequential extraction method developed in this study is expected to be used as an effective and simple recovery procedure for REEs from coal ash and remaining leaching wastewaters.
Key Words
coal ash and leaching waters; environmentally benign solvent; microwave-assisted thermal digestion; rare earth element; sequential extraction
Address
Siyu Chen and Han S. Kim: Civil and Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
Jae Wan Choe: Department of Civil Engineering, Gwangju University, 277 Hyodeok-ro, Nam-gu, Gwangju 61743
