Sustainable Civil Engineering

Biography

Biography: Hossein Ganjidoust

Abstract

Due to the potential contamination of groundwater and surface water in the vicinity of the consumer dye industry, removal of this dyestuffrnwaste is an environmental priority. Water clarity and solubility of gases in the presence of even a small amount of dye is reduced. If there arerncolored substances toxic to lower layers light penetration in the water is low and photosynthesis of aquatic plants and the amount of dissolvedrnoxygen is so low that aquatic animals destroyed. Dyes are stable compounds that are not easily biodegradable and especially azo dyes arernconsidered carcinogenic. Removal of color via various methods of physical, chemical, biological or a combination of them is possible that can bernnoted on physical methods such as adsorption, membrane filtration and ultrasonic waves, chemical methods such as ion exchange, electrolysis,rncoagulation and flocculation, canonical and advanced oxidation and biological methods using algae, fungi and bacteria. Chemical coagulation isrna common method of waste water containing dye. High levels of dissolved solids and sludge in purified effluent is the disadvantage of chemicalrncoagulation. In recent years, electrochemical method because of the versatility and compatibility with the environment as an effective methodrnfor treating wastewater of containing dye industries is taken into consideration. In the electric coagulation, production happens in place ofrncoagulant materials that are result of dissolution metal anode (steel) by passing an electric current. If between the positive anode and negativerncathode that are plugged to electricity, put sewage, an electric field is established as a result of the electrical conductivity of the solution. Byrnelectrolysis of water, tiny bubbles of oxygen and hydrogen produced, and to move upwards and form a blanket on the surface. Bubbles bringrnsuspended particles to the surface and form sludge layer that are mechanically collected. Expected use of electric flotation process simultaneouslyrnwith electric coagulation eliminates requirement to gravity sedimentation unit for the separation the clots and resulting in the separation of bothrnemissions and reduce the cost of the filtration. Researches in the field of electrochemical dye degradation based on electric coagulation andrnflotation property of the produced bubble is rarely used. In this study, reactors designed in a manner intended to electric coagulation propertiesrnand electric flotation can be used simultaneously. In addition, in this study are used innovations such as the use of grille stainless steel electrodesrnwith horizontal arrangement. In this study, the important factors affecting the performance of the synchronized electric conclusion and electricrnflotation system at the; Including electrical conductivity of the solution and initial pH were completed checked out and the effect of thesernparameters on the removal efficiency of acid red 14 from synthetic wastewater, and energy consumption values and anode are determined andrnoptimized. The electrical conductivity 3600 μS/dm and initial pH equal 9 were selected as optimal values and under optimal conditions andrnthe duration of 25 minutes, 99% removal efficiency of dye with initial concentration 250 mg/L is reached and specific energy consumption” 9.5rnkWh/kg Dye Removed”, anode consumption “2.65 Fe /kg Dye Removed” and TSS sludge 9000 mg/L was obtained.. Advantages of this methodrninclude very low consumption of Materials and energy (according to the high rated initial concentration of the dye (250 mg/L) and a smallrnapplied intensity electric current (0.4 A) in this study) as well as low produced sludge that resulted to reduce filtration and sludge disposal costsrncan be noted. Require to simple equipment, high speed and short retention time remove pollutants, easy navigation, require to low amount ofrnchemicals and low produced sludge which has high sedimentation or floating rate with low amount of water are other advantages of this methodrncompared to other methods of dye removal. As a result, this method can be used as an suitable alternative for common filtration methods suchrnas chemical coagulation and flocculation or pre-filtration prior to supplementary filtration of industrial sewage containing dyes.