Implementation of Zero Liquid Discharge Systems in Russian Industry

The article focuses on the implementation of zero liquid discharge (ZLD) systems precluding the pollutant release to the environment at metallurgical, machine-building and metalworking enterprises. The need to change over to such systems is due to two main factors: 1. Significant savings in fresh water used in production; 2. A decrease in the number of all kinds of pollutants reaching the environment with various discharges (purified, insufficiently purified and completely untreated). The main feature of ZLD systems at industrial enterprises is the presence of tailing management facilities, e. g. concentrated wastewater treatment facilities; industrial wastewater sludge treatment facilities; non-recyclable oily wastewater and sludge incineration facilities; reclaimed (recycled) industrial wastewater treatment facilities etc. The development stages of ZLD systems in Russia are presented. In 1973, for the first time in the world’s practice, in the Verkh-Isetsky Metallurgical Plant in the city of Sverdlovsk (now Yekaterinburg), the ZLD developed by Prof. V. I. Aksenov and his colleagues was launched and has successfully operated in the cold rolled transformer steel workshop. As an example of wastewater treatment facility as part of a ZLD system, some technical installation solutions are described in order to treat chemically contaminated acid ferrous-containing wastewater generated in pickling carbon steel. The focus is on the feasibility of implementing local ZLD systems instead of central ZLD systems. The advantages of such local systems are: possible regenerating exhausted process solutions at the place of their formation, obtaining demineralized water, the local treatment of chemically polluted wastewater, lower investment and operating costs.