이원권 배우근 박대원 2024-01-21T07:01:17Z 2024-01-21T07:01:17Z 2022-01-10 2004-06 https://pubs.kist.re.kr/handle/201004/137501 Pilot-scale investigation of two-step biofiltration for municipal wastewater treatment Article 3 Environmental Engineering Research, v.9, no.3, pp.113 - 118 Environmental Engineering Research 9 3 113 118 biofilter two-step biofiltration pre-denitrification municipal wastewater nitrogen removal