Bauman Moscow State Technical University, Moscow, Russia:

B. S. Ksenofontov, Professor at the Department of Ecology and Industrial Safety, Doctor of Technical Science, e-mail: ksenofontov@bmstu.ru
A. S. Kozodaev, Associate Professor at the Department of Ecology and Industrial Safety, Candidate of Technical Sciences
R. A. Taranov, Associate Professor at the Department of Ecology and Industrial Safety, Candidate of Technical Sciences
M. S. Vinogradov, Assistant Lecturer at the Department of Ecology and Industrial Safety

This paper considers the problem of removing metals from waste waters. Various waste water treatment techniques have been analysed, and the most innovative solutions have been identified, which may be implemented to improve the treatment facilities of instrument makers. An experimental study has been carried out that looked at a number of process schemes. Four different purification processes have been investigated. The proposed process makes use of all the equipment available at local treatment plants, but it also involves some additional stages – in particular, reagent treatment (lime in the form of fine-dispersed suspension, coagulant and flocculant solutions), post-treatment in a flotation unit with reagents, filtering and final pH correction. The new process scheme encompasses the following stages: equalization; pH correction; galvanic coagulation; lime treatment; settling with the help of the Aqua-Aurat coagulant and a flocculant; treatment in a flotation unit equipped with an intermediate tank, with coagulant, flocculant and lime milk added to the flotation unit; post-treatment with the help of two filters arranged as a sequence, with aluminum silicate and coal used as the filtering materials; and final pH correction. Purified waste water is collected in a clean water tank, and from the tank it is discharged into a monitoring well.

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