Sharif Digital Repository

Water is one of the world’s most valuable resources, yet it is under constant threat due to climate change, explosive population growth, and waste. One of the most promising efforts to stem the global water crisis is river contaminated, water reclamation and reuse. This study was carried out to investigate in the water quality “S. H. C.” using treatment techniques. Research project was to check out which method give maximum removal of TOC, COD and coliform, fecal coliform and TSS where this parameters exceeded the permissible limits and therefore “S. H. C.” water was contaminated by these parameters. After carrying out the study more from 8 month on water treatment "S. H. C." we get the... 

Fresh water has always been one of the basic needs of human. Thus using different methods for water purification becomes more important in recent years. In classic methods such as distillation chamber and thermal method, water flux was always low and salt rejection wasn’t satisfactory. So investigating new methods such as nanofiltration becomes more important. This method has high efficiency and good water flux in compare with old methods. One of the useful materials in nanofiltration is grapheme oxide (GO). GO sheets make an array of nanochannels and this membrane improves filtration and water flux. Different parameters affect water flux and salt rejection in this membrane. Restructuring... 

In Iran, the technical issues are not considered when changing or replacing the bed of filter. In this regard, less attention is paid for the properties of the materials (e.g. shape, aggregation, effective size and uniform coefficient of grains, etc.) used in the replaced bed of filter. Therefore, the performance of the replaced filter is not good from treated water quality, water production, and backwash interval points of view. In this project, Light Expanded Clay Aggregate, LECA, was chosen as a suitable material to be used in the bed of filter because of its favorable grain shape. The performance of LECA has been examined in both “Single- Media Filter” and “Dual-Media Filter” for... 

In this study three type of nanofiltration membranes were prepared from PVC for water softening; (i) asymmetric PVC nanofiltration membrane, and two different thin film composite (TFC) membranes: (ii) polyamide (PA)/PVC composite membrane (iii) poly vinyl alcohol (PVA)/PVC composite membrane. Asymmetric nanofiltration membranes were prepared by phase inversion. The effect of PVC concentration, solvent (THF) and additive (PVP) on morphology and performance were studied by scanning electron microscopy (SEM) and measuring pure water flux and salt rejection. Increasing PVC concentration decreased pure water flux and increased salt rejection. Adding tetrahydrofuran(THF) decreased the pure water... 

Herein, cupric oxide (CuO)/graphitic carbon nitride (g-C3N4) is synthesized under microwave irradiation for enhanced photoelectrochemical (PEC) performance and photostability. A facile, one-pot method was utilized to directly deposit the nanocomposite onto FTO from a solution containing copper precursor and urea. Possible mechanisms of CuO/g-C3N4 formation and PEC performance improvement were examined via XRD, FTIR, FESEM, XPS, UV-Vis, and PL. Controlled amounts of urea determined the morphological evolution of CuO and the formation of a protective carbon layer, while its excess quantity converted to g-C3N4 in the presence of CuO. Through heat treatment of the nanocomposite, carbon-doped... 

Membranes are one of the best water and wastewater treatment methods that could successfully replace other less-effective conventional techniques such as adsorption, coagulation, etc. Moreover, relative to other techniques, the quality of the water produced by membrane separation is very high compared to others. One of the main drawbacks of membrane treatment is fouling of the surface and internal pores of the membranes restricting its widespread application in the industry.In this study, TiO2@MIL-88A (Fe) photocatalyst and polyacrylonitrile membrane were modified with this photocatalyst to remove humic acid under visible light irradiation inside the PMR photocatalytic reactor was... 

One of the most efficient and effective methods of water and wastewater treatment is the use of membranes and can be a good alternative to traditional methods such as adsorption, chemical coagulation and .... One of the limitations of this method is membrane fouling, which limits its use in industry.In this study, ultrafiltration membrane made by phase inversion method from a combination of PVDF and SPES polymers and surface modified with hyperbranched polyethylene imine and its performance in cationic coating paint purification was investigated. Also, the performance of this membrane has been investigated by calculating the separation rate, pure water flux, contact angle and specifications... 

to achieve a stable elimination of colloidal suspended particles, polymer flocculants such as polyacrylamide and its derivative have been more used. To improve the performance of removing turbidity, reducing settling time, and better dewatering from sediments, hydrophobic styrene monomer copolymerized with acrylamide monomer. In this study the copolymer of acrylamide and styrene was synthesized by inverse emulsion polymerization, then this copolymer undergoes hydrolysis to form anionic groups on the polymer backbone. FT-IR, H NMR, and TGA analyses were carried out to investigate the structure of the copolymer. To evaluate flocculation, turbidity tests, zeta potential, and sedimentation rate... 

Nowadays capacitive deionization (CDI) has attracted a lot of attention for water treatment. CDI is an emerging water treatment technology that uses electrophoretic driving forces for desalination of water. During the CDI process, ions are adsorbed onto the surface of electrodes by applying a low voltage electric field (DC<2V). In addition, the regeneration of the electrodes contains desorption of the electrosorbed ions from the surface of the electrodes to the water in the absence of the applied electric field. In the mechanism of CDI, separation and accumulation of ions in the electric field are the main processes and no additional chemicals are required in this technology. Therein,... 

In this study, membrane distillation was used for desalination of high saline water. Recently, the synthesis of nanoparticles for the synthesis of membranes for membrane distillation has shown incredible improvement in the morphological properties, flux, and rejection. In this study, by incorporating UiO-66 functionalized with Palmitic acid into PVDF/PEG polymer solution we could improve membranes properties. Functionalization of UiO-66 with Palmitic acid was confirmed with FTIR, XRD, BET, SEM. In the membrane containing 3% Palmitic acid-UiO-66, the flux was increased by 46.5%, resulting in a flux of 12.6 LMH, and the salt rejection was improved from 99.5% to 99.9%. These results confirmed... 

Statistics show that plastic production in the world is increasing, with 335 million tonnes in 2016 reaching 367 million tonnes in 2020. Since the presence of plastics in the dimensions of micro and nano, especially in aquatic environments can have adverse effects on human health and other living organisms, it has raised major environmental concerns. Therefore, it is necessary to think of measures to remove them and develop efficient methods for eliminating and decomposing microplastics. Recently, the advanced oxidation processes have attracted much attention because of the ability to eliminate recalcitrant compounds. In this study, electrochemical techniques and Fenton-based techniques for... 

Freeze desalination as a water refining method has attracted a lot of attention due to its potential in lowering process energy consumption compared to other methods. This method is based on the fact that the dissolved salt is drained from the saline water during its freezing. The current study conducts a parametric study on freezing saline water in a cylindrical container to investigate the impact of geometric and functional factors affecting the desalination quality. This has been done by examining the aforesaid factors in the form of dimensionless parameters such as thermal Grashof number, solutal Grashof number, and Jacob number. In addition, in order to improve the desalination, a novel...