Nauka ta progres transportu (Apr 2018)
WASTEWATER TREATMENT OF INDUSTRIAL ENTERPRISES BY THE NATURAL METALS
Abstract
Purpose. The paper deals with the galvanic coupling effect (time of treatment and other factors) on the removal of oil, synthetic surface active substances (SSAS), chromium, etc. from waste process solutions used in metalworking. It presents an overview of wastewater treatment technologies from heavy metal ions based on physicochemical processes. Methodology. To restore hexavalent chlorine to trivalent, authors decided to use the existing averager of acid-alkaline effluents as a kind of galvanic coagulant, for which it was filled with iron turnings and crushed coke. Findings. Authors researched wastewater of the electrotechnical industry and highlighted sorption methods for their purification with the use of coagulants, ion exchange. They considered a new galvanocoagulation method for purification from heavy metal (HM) ions (arsenic, chromium, non-ferrous metals), as well as petroleum products and organic substances dissolved in water. Permissible values of the quality indicators of wastewater and water in reservoirs are given. The classification of heavy metal groups according to the degree of toxic effect is presented. Their influence on the human body is considered. The use of the «LOTOS» reactor in the technological process of electroplatings wastes cleaning allows: to process them in a single stream, to abandon special reagents for cleaning effluents from hexavalent chromium and cyanides, to exclude the need for acidification of effluents, to reduce the use of alkaline reagents up to complete rejection of them, to reduce the equipment rate and number of production personnel (their main function is to purify solutions containing up to 1 g/dm3 of hexavalent chromium. The reactor consists of unified modules, mounted in a single frame. Originality. On the basis of experimental research work, it was established possibility in principle of treatment of all liquids under research by the galvanocoagulation method. The method consists in contacting of wastewater simultaneously with copper and steel shavings (scrap) without using an external source of electric current. Practical value. The article highlights the topical issues of wastewater treatment from salts of heavy metals, which is necessary for sanitary and ecological purposes. We propose modern energy-saving and low-energy-consuming simple methods, such as the galvanic technique. The modern plant is widely used in industry, electroplating and metalware production. The described methods have a number of positive properties in the economic and energy relations. Salts of heavy metals are dangerous pollutants for both sewage and drinking water. Therefore, water treatment is a very important problem in the field of the environment of our country and abroad. The cleaning effect is achieved within 95 ... 98%.
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