Využití sorbentů k odstranění zbytkové koncentraci niklu v upravené odpadní vodě

Abstract

The submitted thesis deals with the possibility of using biosorbent, which is a mixture of cones from coniferous trees to remove hazardous metals contained in hazardous waste, which is disposed of in the neutralization station. Originally, attention was paid to the most problematic metal, which was a nickel, but the efficacy of the tested sorbent in removing other metals, such as zinc, copper and iron, was also monitored. Other prescribed parameters for the discharge of treated wastewater into the sewer system were also monitored. These were mainly pH, dissolved inorganic salts (RAS), suspended solids (NL) and chemical oxygen demand by the chromate method. First, the sorbent was tested in the laboratory in batch mode. Laboratory tests with real wastewater have shown that the biosorbent can be used to remove hazardous metals. Under the given conditions, 96% nickel and 19% zinc were removed after 20 min when using an activated sorbent with 0.1 mol l-1 sodium hydroxide. Using unactivated sorbent, 93% nickel and 31% zinc were removed. The sorbent tested has also proved its worth in the field tests. It was used for the pre-treatment of hazardous waste in the preparation pit, where the concentration of hazardous metals was significantly reduced. However, even after neutralization, the treated water did not meet the emission limits for discharges into sewers. The cone mixture was therefore used in a filter unit upstream of the Parshall trough. After passing through the filter unit, which was made of a mixture of cones, the concentration of all monitored parameters decreased to a minimum and the values met the prescribed emission limits. The mixture of cones from coniferous trees is usable for the treatment of a total of 10,000 litres of wastewater in order to meet the emission limits for discharges into the ZKL sewerage system. After that, its efficiency decreased, and it was necessary to replace it. However, the biosorbent used can still be used to densify the residual sludge in the waste treatment pit, which contributes to reducing the overall cost of removing residual hazardous waste, which is thus converted from liquid to solid waste.