TY JOUR TI PRINCIPLES OF CIRCULAR ECONOMY IN CREATING CLOSED CYCLES FOR PROCESSING SEWAGE SLUDGE INTO ORGANIC FERTILIZER KW circular economy KW use of secondary resources KW sewage sludge recycling KW organic fertilizer KW SWOT analysis KW efficiency JO Actual directions of scientific researches of the XXI century: theory and practice AU Momot, R.V. AU Nebesnaya, A.Y. PY 2024 IS 12 PB FSBE Institution of Higher Education Voronezh State University of Forestry and Technologies named after G.F. Morozov