Sharif Digital Repository

Due to the increasing number of Advanced Oxidation Processes (AOPs) that are exploited to eliminate emerging and recalcitrant contaminants from water supplies, photocatalytic degradation of Reactive Blue 21 dye using Zinc Oxide nanoparticles is investigated in both a slurry phase and an immobilized photoreactor. The structural and optical properties of the prepared ZnO nanoparticles were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and UV-Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The effects of photocatalyst concentration, calcination temperature, pH and UV lamps were optimized in the slurry phase photoreactor. It was shown that 250 ppm of ZnO that was... 

Nowadays, water pollution and water sources decreasion, is one of the important issues of our world. Treatment of polluted water and wastewater and recycling of those to industries and common uses, is very necessary. Dyes, is one of the biggest parts of water pollutants, especially, in textile plants. There are some ways for dye removal, in the industries; including biological, chemical and physical methods. Among of these methods, physical removal of dyes through adsorption (with Activated Carbon or other adsorbents), is very popular. Hydrogels are three-dimensional hydrophilic polymer networks, introducing very good swelling rate, mechanical properties and pollutants adsorption. In this... 

In this thesis, a novel graphene oxide (GO)/sodium alginate (SA)/polyacrylamide (PAM) ternary nanocomposite hydrogel with excellent mechanical performance has been fabricated through freeradical polymerization of acrylamide (AAm) and SA in the presence of GO in an aqueous system followed with ionically crosslinking of calcium ions. Physical and chemical characteristics of the composite were investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling behaviors of the composite hydrogels were investigated under varying conditions of time and pH. The optimized swelling capacity in standard conditions was found to be 1711% per gram of the hydrogel. The... 

In recent years, because of the increase in population and more accessibility of health facilities for people, an increase has occurred in water resources consumption. Recycling water has become so much valuable as the freshwater of the world is limited. Besides the advantages of treated water has for people, discharging the untreated wastewater to the rivers could cause many problems for human health. Many kinds of pollutions, such as textile effluent, are not easy to be treated by traditional methods because of their resistance to them. As these types of wastewater have severe negative effects on living things (both humans and animals), new treatment technologies should be considered. The... 

In the present study, the electrochemical oxidation process was introduced as a green process for complete degradation and removal of non-biodegradable pollutants from aquatic environments and effluents of various industries without the need to use chemicals and toxins. Research stages include comprehensive preliminary studies in the field of electrochemistry and wastewater treatment, software design of electro-oxidation reactor using titanium mesh anode and stainless steel cathode mesh inside a body made of polypropylene, designed cell construction and then evaluation of device performance in polluting environment Are different. In software simulation using COMSOL MULTIPHYSICS software, it... 

Population growth and community development has a large role in the demand for fresh water for a variety of uses. In recent decades, over-harvesting and abusing of water resources has led to water crisis. On the other hand, the increase in various pollutants, in addition to environmental hazards, is a threat to groundwater pollution and the existence of valuable fresh water. Due to the potential hazards of emerging pollutants, new treatment technologies such as advanced oxidation and photocatalytic methods are being developed. One of the contaminants resistant to traditional treatment methods is textile contaminants. In this research, by designing and constructing a photocatalytic reactor,... 

The best method for stabilizing sludge is anaerobic digestion, In addition to reducing the amount of volatile solids; it produces biogas, which can be considered as a sustainable energy source for wastewater treatment plants. However, the most important factor limiting the process of digestion is the sludge hydrolysis, the best way to increase the speed of hydrolysis is to pre-treatment the sludge before entering the digester; One of the most effective pretreatment methods is pre-treatment by ozone gas, This gas, which is highly unstable, quickly reacts with the wall of the bacterial cell and oxidizes it due to its high oxidizing properties And accelerates the process of sludge hydrolysis.... 

Biological layers are one of the main problems related to water transfer with pipe lines which are formed through time in the inner surface of the pipes by the water nutrients. Hence, the inner surfaces in the pipe lines and water refineries should be made in order not to let these biological layers to be made. The reason is that when the biofilm is formed on these surfaces, the traversing water is polluted. Dredging of these pipes is not only necessary in most of the countries in the world and needs huge amounts of water but is also very complex and expensive.In this research, nanomaterials, namely ZnO, T〖iO〗_2،S〖iO〗_2 have been used to cover the surface of concrete and steel pipes (The... 

One of the Advanced Oxidation Process (AOP) is Photocatalyst method. Structure of this method is according to three foundation: 1. Catalyst, 2. Source of energy, 3. Wastewater. Progress of human activity around variety of fields such as pharmaceutical, plastic industry, and medical science has produced some micro pollutants such as Bisphenol A (BPA) that has aroused the public concerns in recent years. The half-life of this components in water, air and soil is too long, so typical methods such as biological method, activated sludge and carbon adsorption are inefficient in removing BPA. This work describes a visible light responsive Carbon Quantum Dots(CQDs) embedded on TiO_2 nanoparticles... 

With decreasing fresh water availability and growing demand for clean water, alternative water sources are used in many parts of the world. At the same time, the increasing environmental pollution with a variety of manmade chemicals with known or unknown effects on the aquatic wildlife and human health is an uncontested reality. These emerging pollutants include pharmaceuticals and personal care products, pesticides and hormones. Due to the high sensitivity of color pollutants and many concerns about this issue, in this study, by designing and optimizing a falling film reactor, the removal of Basic red 46 dye from water by advanced oxidation method is investigated. The photocatalytic...