Abstract
<jats:p>The treatment of industrial wastewater containing toxic impurities is a difficult environmental challenge. It can be solved by using a combination of free-floating and carrier-attached reactive sludge in reactors. Biomass carriers are often made from various synthetic materials (polyamide, polyester, polypropylene, polyurethane, polyethylene), sometimes with the addition of organic and mineral components. In this paper we substantiate the expediency of using secondary resources as a carrier of fixed biomass in the process of biological wastewater treatment. We use fine fraction of recycled PET flakes (5–10 mm), light fraction of PET bottle recycling waste (labels) and carbon-synthetic carrier based on residues after thermodesorption of oil-containing waste and low-pressure polyethylene waste. The most effective biomass fixation occurs on light fraction of PET bottles recycling waste (2.25 g/g of carrier) and carbon-synthetic carrier based on residues after thermodesorption of oil-containing waste and low-pressure polyethylene waste (3.5g/g of carrier). Application of these biomass carriers allows increasing the efficiency of oily wastewater treatment in comparison with the technology with free-floating sludge by 7 % for oil products and by 17 % for chemical oxygen demand (COD). This corresponds to a treatment efficiency of 97 % for oil products and 92 % for COD. Thus, the species diversity of free-floating microorganisms of activated sludge increases by almost 2 times as well as the number of higher trophic level microorganisms in the sludge, the sedimentation properties of activated sludge improve and transparency of treated wastewater increases as a result of application in the biological treatment of oily wastewater a biomass carriers on secondary resources base.</jats:p>