Mechanical Enhancement and Water Treatment Efficiency of Nanocomposite PES Membranes: A Study on Akçay Dam Water Filtration Application

© 2024 The Authors. Published by American Chemical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Polymeric membranes are widely used in water treatment because of their ease of fabrication and low cost. The flux and purification performance of membranes can be significantly improved by incorporating appropriate amounts of nanomaterials into the polymeric membrane matrices. In this study, neat poly­(ether sulfone) (PES), PES/nano copper oxide (CuO), and PES/nano zinc oxide (ZnO) membranes are fabricated via phase inversion. The pure water flux of the neat PES membrane, which is 355.14 L/m2·h, is increased significantly with the addition of nano-CuO and nano-ZnO, and the pure water fluxes of the nanocomposite membranes vary in the range of 392.65–429.74 L/m2·h. Moreover, nano CuO and nano ZnO-doped PES nanocomposite membranes exhibit higher conductivity, color, total organic carbon, boron, iron, selenium, barium, and total chromium removal efficiencies than neat PES membranes. The membrane surfaces examined by Scanning Electron Microscopy (SEM) after water filtration revealed that those containing 0.5% wt. nano CuO and nano ZnO are more resistant to fouling than the membrane surfaces containing 1% wt. nano CuO and nano ZnO. Based on the results of this study, 0.5% wt. nano ZnO-doped PES membrane is found to be the most suitable membrane for use in water treatment due to its high pure water flux (427.14 L/m2·h), high pollutant removal efficiency, and high fouling resistance. When the mechanical properties of the membranes are examined, the addition of CuO and ZnO nanoparticles increases the membrane stiffness and modulus of elasticity. The addition of 0.5% and 1% for CuO leads to an increase in the modulus of elasticity by 57.95% and 324.43%, respectively, while the addition of 0.5% and 1% for ZnO leads to an increase in the modulus of elasticity by 480.68% and 1802.43%, respectively. At the same time, the tensile strength of the membranes also increases with the addition of nanomaterials.Peer reviewe

Optimal Divisible Binary Codes from Gray-Homogeneous Images of Codes over R-k,R-m

In this work, we find a form for the homogeneous weight over the ring R-k,R-m, using the related theoretical results from the literature. We then use the first order Reed-Muller codes to find a distance-preserving map that takes codes over R-k,R-m to binary codes. By considering cyclic, constacyclic and quasicyclic codes over R-k,R-m of different lengths for different values of k and m, we construct a considerable number of optimal binary codes that are divisible with high levels of divisibility. The codes we have obtained are also quasicyclic with high indices and they are all self-orthogonal when k(m) >= 4. The results, which have been obtained by computer search are tabulated

Investigation of the catalytic reaction kinetics of Fe(III) on Fe(II) oxidation at various pH values

One of the methods of removing Fe(II) ions from drinking water is their oxidation and precipitation as ferric hydroxide Fe(OH)3. The catalytic effect of Fe(OH)3 flocs on the oxidation of Fe(II) has been investigated by several researchers [1, 2]. In this study, the catalytic effect of Fe(OH)3 slurries on the oxidation of Fe(II) was studied at three different pH values, 6.2, 6.5, and 6.7, with Fe(OH)3 concentrations ranging from 0 to 1000 mg/l using a batch reactor. The reaction rate constant (kcat) was found to increase linearly with increasing Fe(III) concentrations up to 500 - 600 mg/l decreasing again with higher concentrations. The model developed for the batch system was applied to a continuous system. The results showed that smaller reactors can be used due to the catalytic effect of Fe(OH)3 on Fe(II) oxidation

Catalytic effects of Fe(III) during oxygenation of Fe(II) in continuous flow iron removal systems

In this study, an iron removal process, which makes use of the catalytic effect of ferric iron, is proposed. For this purpose, a lab-scale continuous flow aeration/ sedimentation unit with or without recycling was built. The aim of the study was to verify the validity of the findings of batch-type oxidation experiments also for continuous flow conditions. The efficiency of oxidation was about 57-79% when the system was operated without recycling. Fe(II) removal efficiencies could be increased to 80-89%, 90-97% and 98-99.6% for the recycling ratios of 50%, 80% and 100%, respectively. The increase of Fe(II) removal was explained by an increase of ferric concentration in the aeration tank as a result of recycling. The higher the Fe(III) concentration in the aeration tank the better was the Fe(II) removal efficiency up to a Fe(III) concentration of 300 mg/l. Beyond this level, no significant increase in removal efficiency of ferrous iron was observed with increasing ferric iron concentration

Oxidation of Manganese (II) with air in water treatment

Manganese is the second most common constituent after iron of impounded water and many well waters. It causes difficulties in public supplies and in industrial supplies. In this study, the oxidation of Manganese(II) is studied in batch reactors in which the concentrations of manganese(IV) was in the range 0-300 mg/L. This study has demonstrated the catalytic effect of MN(IV) on the Mn(II) oxidation by air to the MN(IV) levels of 100 mg/L. A quadratic equation has been obtained to determine the catalytic reaction rate constant, kcat, as a function of Mn(IV)

An experimental study on iron removal with ferric sludge recycling

An iron removal process, which makes use of the catalytic effect of ferric iron, is proposed. For this purpose, the reaction kinetics derived from the data of the batch experiments was applied to the continuous flow system. Based upon this reaction kinetics, it has been theoretically demonstrated that the volumes of aeration tanks can be significantly reduced by keeping a high concentration of ferric iron in the reactor. However, in natural waters, Fe(II) is found commonly to be in the range of 0.01-10 mg/l. These ferrous iron concentrations are not high enough to maintain the high concentrations of ferric iron in the aeration tank. Therefore, similar to the activated sludge processes used in wastewater treatment, it is suggested that the required Fe(III) concentrations can be maintained by recycling Fe(OH)3 sludge back to the aeration tank. It is known that the oxygenation of ferrous iron is catalyzed by the reaction product, ferric hydroxide. Catalytic action of the ferric iron sludges on the oxidation of ferrous iron by aeration has been identified and the kinetics of this catalytic reaction has been formulated by the authors. The oxidation of Fe(II) was studied in batch reactors in which the concentration of Fe(III) was in the range of 0-600 mg/l. The oxygenation rate increased linearly with the increasing Fe(III) concentrations up to 50 mg/l and a second-order polynomial relationship was found between the reaction rate and the Fe(III) concentrations in the range of 50-600 mg/l. The required volume (V) of the aeration tank and the effluent Fe(II) concentrations were determined as a function of the Fe(III) concentration. The volume of the aeration tank required for the same Fe(II) conversion was reduced by a factor of 15 when the Fe(III) concentration was raised from 0 to 600 mg/l at pH=6.7. No incremental benefit of the increase of Fe(III) concentration was observed at Fe(III) levels beyond the 600 mg/l. This study has experimentally demonstrated that significant savings can be achieved in iron removal systems by recirculating the Fe(III) sludges back to the aeration tank. An iron removal process that makes use of the catalytic effect of ferric iron is proposed. With this process, significant savings can be achieved in iron removal systems by recirculating the Fe(III) sludges back to the aeration tank