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Effect of aeration and hydraulic loading rate on nitrogen removal by subsurface infiltration systems
Author(s) -
Zheng Fanping,
Huang Linli,
Pan Jing,
Qi Shiyue,
Tan Chaoquan,
Xiao Lu
Publication year - 2019
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.1002/wer.1030
Subject(s) - aeration , anoxic waters , nitrogen , chemical oxygen demand , chemistry , infiltration (hvac) , organic matter , hydraulic retention time , anaerobic exercise , environmental chemistry , environmental engineering , denitrification , dissolved organic carbon , oxygen , pulp and paper industry , environmental science , wastewater , materials science , biology , physiology , organic chemistry , engineering , composite material
This study investigated the effect of hydraulic loading rate ( HLR ) on matrix dissolved oxygen ( DO ), organic matter removal, nitrogen removal, N 2 O emissions, and the abundances of functional genes participating in nitrogen removal in intermittent aerated mode ( IAM ) and nonaerated mode ( NAM ) subsurface infiltration systems ( SIS s). In contrast to NAM SIS s, IAM SIS s were able to create aerobic conditions in the upper matrix (above 50 cm depth) and anoxic or anaerobic conditions in the lower matrix (below 80 cm depth). Subsequently, this enhanced the abundance of functional genes related to nitrogen removal. Chemical oxygen demand ( COD ) and nitrogen removal performance were significantly higher under IAM SIS s than with NAM SIS s. Under a HLR of 0.3 m 3 /(m 2 d), the IAM SIS was able to achieve low N 2 O emissions (12.6 mg/[m 2 d]) along with removal efficiencies of 90.5%, 91.4%, and 85.7% for COD , ammonia nitrogen ( NH 4 + ‐N), and total nitrogen ( TN ), respectively. Practitioner points Intermittent aeration successfully realized sequential aerobic and anaerobic conditions at 50 cm depth and at 80 and 110 cm depths of a subsurface infiltration system. Intermittent aeration reduced N 2 O emissions and improved hydraulic loading rate and organic matter, nitrogen removal efficiencies. Intermittent aeration enhanced the abundances of amoA, nxrA, napA, narG, nirS, nirK, qnorB, and nosZ.