Membrane treatment of water containing spent cooling fluids

Abstract

© 2020, "Ore and Metals" Publishing house. All rights reserved. The possibility for purification of spent emulsions of cooling fluids (coolant) formed during the processing of steels from alloyed and ferrous steels using membrane methods has been investigated. The main physicochemical and chemical methods for treatment of spent coolant are briefly reviewed: coagulation and flocculation, flotation, adsorption, oxidation using various oxidizing agents. The model emulsion based on I-20A oil was cleaned using polyacrylonitrile membranes (PAN) with a pore size of 2; 5 and 10 nm. Graphical dependences of productivity on the process time and pore size of PAN membranes are given and the values of chemical oxygen consumption (COD) are determined. Based on experiments with model emulsions, studies were conducted on the membrane separation of spent Inkam-1 brand coolant used in the metalworking process at PJSC KAMAZ using ultrafiltration and reverse osmosis processes. It was shown that during membrane purification of the spent coolant emulsion solution, reverse osmosis filtrate meets the regulatory requirements for water to be discharged into the sewage system. It was determined that in addition to the organic component in the spent coolant, heavy metal ions and ani-ons are effectively retained during reverse osmosis. It was revealed that the selectivity of reverse osmosis for various ions mainly coincides with a range of increasing in their hydration energy: and with an increase in the metal ion charge. The use of a concentrate of spent coolant emulsion as a basis for creating an inhibitory composition designed to inhibit corrosion of 20 steel against the action of formation waters generated during oil production was proposed.