Chromium-containing wastewater treatment by means of using galvanocoagulators

Abstract

In this study, a galvanocoagulator was used for the treatment of chromium-containing wastewater. Its principle of operation is based on the use of processes for reducing Cr(VI) ions to the Cr(III) state using a galvanic pair “copper-iron” without applying an external electric field. In this case, the reduction of hexavalent chromium ions to trivalent occurs due to the oxidation of iron ions, which, when dissolved, pass into the solution. To speed up the process of iron dissolution, compressed air is supplied to the galvanocoagulator. The conversion of Cr(VI) and Cr(III) into insoluble compounds is performed by adding alkali solutions. The resulting suspension is removed from the water by settling and filtering methods. As a result of research, the possibility of effective treatment of chromium-containing wastewater using the method of galvanocoagulation was established; the technological parameters of the galvanocoagulator were determined. The hydraulic size of the suspension formed after processing of chromium-containing effluents in a galvanocoagulator is determined, which allows designing treatment facilities for the removal of heavy metal hydroxides by settling.

Use of higher aquatic vegetation for post-treatment of wastewater

“…The main task of cleaning the Lower Kaban Lake will be taken over by plants that will purify the water from suspension, mixtures, phenols and phosphates, heavy metals, from harmful substances of galvanic production and a number of other harmful substances. Wastewater from galvanic production can be treated using galvanic coagulators [23]. Methods for purifying water from surface sources from suspended matter are detailed in the article [24].…”

Treatment of oil-containing wastewater of machine-building enterprises using pressure hydrocyclones

“…Kazan State University of Architecture and Engineering (KSUAE) has developed devices that combine the treatment of oil-containing wastewater in pressure hydrocyclones, succeeded by purification from petroleum products and suspended substances by sedimentation. These installations are called the «hydrocyclone -sump block» (HSB) [10,11]. Coalescing nozzles made of granular materials are used to intensify the deposition of oily wastewater [12].…”

Study of the processes of the purification of water from surface sources from petroleum products

“…Since petroleum products are often used in various sectors of the national economy, they, together with industrial wastewater, enter surface sources, polluting natural waters [1][2][3].…”

“…Large drops of petroleum products that are suspended in natural water (emulsions of the «oil in water» type are well removed by mechanical methods. To separate the particles of petroleum products from water in the gravitational field, sedimentation tanks of various designs are used [2,4,5]. Filters with granular loading are also used to purify natural waters from petroleum products [2,6,7].…”

“…Kazan State University of Architecture and Engineering (KSUAE) has created devices of the «hydro cyclone-sump block» type for the removal of petroleum products with a sufficiently high content from water. These installations consist of batteries, elementary hydro cyclones, and settling tanks with various devices [2,3].…”