Очистка нефтесодержащих вод окислением на композиционном угольном сорбенте

Abstract

Wastewater, treated at sewage treatment plants, contains oil products at low concentrations predominantly in a dissolved state and the use of sorption or destructive methods will be the most effective. The present paper proposes to combine the advantages of both methods. Activated carbon, among others, is widely used for the deep removal of oil and petroleum products from wastewater. MnO₂ proved to be a good oxidizer for the removal of organic pollutants. The composite sorbent was synthesized based on activated carbon Filtrasorb 300. It has high adsorption capacity and a large number of transport pores and is designed to remove organic compounds from water. The oxidizer MnO₂ was precipitated in the pores of the carbon as a result of treatment with a KMnO₄ solution. The process of MnO₂ precipitation on the carbon surface was studied depending on the initial concentration of KMnO₄ from 1 to 52 g/dm³. With contact 24 h, the mass fraction of MnO₂ in the carbon was almost independent of the concentration of the permanganate solution and reached up to 39.7 %. MnO₂ forms nanoparticles that gradually fill in the pores of the carbon sorbent. Obtained material will have a greater oxidizing ability and a longer operating time without regeneration. On the other hand, too much MnO₂ significantly reduces the contact area of the adsorbent with the solution, so the oxidation rate slows down. A sufficient duration of modification of coal is considered 15 minutes at a concentration of KMnO₄ solution 1 g/dm³. The synthesized composite sorbent contained 0.5% MnO₂. The number of acidic surface sites after carbon modification doubled from 0.55 to 1.1 mmol-eq/g. The specific sorption capacity of the initial carbon after 24 h contact time was 68 mg/g, while for the synthesized composite sorbent it was 122 mg/g and continued to increase.