Effect of oxygen states in horizontal subsurface flow constructed wetlands on the removal of organic matter, nutrients, some metals and octylphenol

Abstract

Constructed wetland is a low cost, effective technology and it is still in the state of improvement to enhance the treatment efficiency, especially in nutrient and trace elements treatment. This study investigated the effect of aerobic and anoxic conditions in Horizontal Subsurface Flow Constructed Wetland (HSFCW) on nutrient, organic, metal and Octylphenol - OP (Endocrine disrupting chemical) treatment. Two HSFCWs were constructed: HSFCW1 with three aerobic compartments; HSFCW2 with two aerobic compartments, one anoxic compartment. The two HSFCWs had the same design parameters (fiters, plants), except oxygen conditions. The results showed that aerobic and anoxic HSFCW may increase the efficiency of Nitrogen removal by 10%, but decreased by 11% in the efficiency of OP treatment (one of the EDCs). The efficiency of treatment of pollutants, including NH4+-N, COD, TP, Mn, Fe, Al and Cu between two HSFCWs were not significantly different; the average efficiency was 99%, 84%, 97%, 96%, 96%, 72% and 73%, respectively. Therefore, the anoxic compartment of HSFCW still provided the effective removal of organic matter, Manuscript received September 29th, 2017; accepted 24th December, 2017 This study was funded by CARE RESCIF under grant number Tc-TTC-2017-05. An Truong Nguyen, Tam Minh Thi Le, Viet Quoc Tran, Trang Huyen Thi Nguyen are with the CARE, Ho Chi Minh City University of Technology, VNU-HCM, Vietnam (truongan.hcmut@gmail.com, minhtamnt2006@hcmut.edu.vn, ngthtrang@hcmut.edu.vn) Viet Ngoc Truong, Luan Thanh Nguyen, Phi Hoang Tan Nguyen are with the Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology, VNU- HCM, Vietnam (truongngocviet93@gmail.com) metals and octylphenol, but it also improved nitrogen removal efficiency by up to 92%.