Opoka in coagulation of slightly polluted surface water

The coagulation of low-water with reagent purification is difficult because of the low concentration of suspended solids. The increased consumption of coagulant in this case leads to an increase in the content of residual aluminum or iron in water leaving the treatment facilities of the water supply. Clapping can be intensified by adding mineral opacifiers to the water, the particles of which play the role of additional centers of flocculation, weigh the flakes and increase the degree of water purification due to sorption processes occurring on their surface. In the paper, the efficiency of using opoka for the turbidity of slightly contaminated surface waters is investigated. The composition of this rock contains a significant amount of silicon dioxide, which determines the sorption properties of this material. The study was carried out using the jar-test experiment, using the water of the Shershni reservoir on the Miass River. It was found that the use of the opoka is expedient with a two-stage water purification scheme "sedimentation-filtration". The opoka was dosed in the form of an aqueous suspension prior to the administration of the coagulant. The reduction of the residual aluminum content in the filtrate is more effective by 40% compared to the experiment without the opoka. It is noted that in the conditions of low temperatures the effect of opoka is more pronounced. (paper)