TY - JOUR
T1 - Nitrogen removal in response to plants harvesting in two kinds of enhanced hydroponic root mats treating secondary effluent
AU - Sun, Shanshan
AU - Gao, Lei
AU - He, Shengbing
AU - Huang, Jungchen
AU - Zhou, Weili
N1 - Funding Information:
The study was supported by the National Natural Science Foundation of China Under Grant (No. 51678356 ); the Science and Technology Project of Zhejiang Province (No. 2015C03016 ); the Program for Chinese National Key Projects of Water Pollution Control and Reclamation ( 2017ZX07205003 ).
Publisher Copyright:
© 2019
PY - 2019/6/20
Y1 - 2019/6/20
N2 - Hydroponic root mats (HRMs) are a green technology for various wastewaters purification. However, plants wilting will inevitably reduce the purification efficiency of HRMs. Harvesting as an important way of plant management for a better understanding of sustainability of HRMs has always been highly controversial. The goal of this study was to investigate the impacts and sustainability of harvesting on nitrogen removal and greenhouse gases (CH 4 , N 2 O) emissions of the two kinds of enhanced hydroponic root mats: autotrophic hydroponic root mat (AHRM) and heterotrophic hydroponic root mat (HHRM) for treating secondary effluent. The results showed that harvesting temporarily decreased nitrogen removal efficiency of the two systems, and removal efficiency recovered quickly because of the existence of external electron donors. The effects of harvesting are ordered as: HHRM > AHRM, NO 3 − -N > NH 4 + -N. Increasing C/N, S/N would reduce the impact of temperature on harvesting systems. Harvesting also increased the emission of greenhouse gases, and increasing C/N(=6), S/N(=1.1) could significantly reduce greenhouse gases emission of the harvesting systems at low temperature. In addition, composition analysis of the shoots of the harvested plants was also conducted, and the results showed that N contents of growing shoots were significantly higher than that of withered shoots. In order to make the hydroponic root mats sustainable, harvesting before the plants wilt is more effective in removing nitrogen from the system permanently and maintain a sustainable system.
AB - Hydroponic root mats (HRMs) are a green technology for various wastewaters purification. However, plants wilting will inevitably reduce the purification efficiency of HRMs. Harvesting as an important way of plant management for a better understanding of sustainability of HRMs has always been highly controversial. The goal of this study was to investigate the impacts and sustainability of harvesting on nitrogen removal and greenhouse gases (CH 4 , N 2 O) emissions of the two kinds of enhanced hydroponic root mats: autotrophic hydroponic root mat (AHRM) and heterotrophic hydroponic root mat (HHRM) for treating secondary effluent. The results showed that harvesting temporarily decreased nitrogen removal efficiency of the two systems, and removal efficiency recovered quickly because of the existence of external electron donors. The effects of harvesting are ordered as: HHRM > AHRM, NO 3 − -N > NH 4 + -N. Increasing C/N, S/N would reduce the impact of temperature on harvesting systems. Harvesting also increased the emission of greenhouse gases, and increasing C/N(=6), S/N(=1.1) could significantly reduce greenhouse gases emission of the harvesting systems at low temperature. In addition, composition analysis of the shoots of the harvested plants was also conducted, and the results showed that N contents of growing shoots were significantly higher than that of withered shoots. In order to make the hydroponic root mats sustainable, harvesting before the plants wilt is more effective in removing nitrogen from the system permanently and maintain a sustainable system.
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U2 - 10.1016/j.scitotenv.2019.03.182
DO - 10.1016/j.scitotenv.2019.03.182
M3 - Article
C2 - 30903893
AN - SCOPUS:85063108034
VL - 670
SP - 200
EP - 209
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
ER -