TY - JOUR
T1 - The combined effects of macrophytes (Vallisneria denseserrulata) and a lanthanum-modified bentonite on water quality of shallow eutrophic lakes
T2 - A mesocosm study
AU - Zhang, Xiumei
AU - Zhen, Wei
AU - Jensen, Henning S.
AU - Reitzel, Kasper
AU - Jeppesen, Erik
AU - Liu, Zhengwen
N1 - Funding Information:
This study was supported by Chinese National Key Research and Development Project (Grant No. 2017YFA0605201 ) and “135” Strategic Planning of Nanjing Institute of Geography and Limnology, CAS (Grant No. NIGLAS2017GH01 ). Erik Jeppesen was supported by the Centre for Water Technology ( WATEC, Aarhus University y, and the TÜBITAK outstanding researchers program 2232 (project 118C250 ). Kasper Reitzel was supported by the Poul Due Jensen/Grundfos foundation. We thank Manli Xia, Chunyu Yin, Yiming Gao, Hongkang Ji, Zifan Zhao, and Deshan Zhou for assistance in the determination of plant traits and water sample measurements, and Anne Mette Poulsen for English edition.
Publisher Copyright:
© 2021 Elsevier Ltd
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/5
Y1 - 2021/5
N2 - Establishment of submerged macrophyte beds and application of chemical phosphorus inactivation are common lake restoration methods for reducing internal phosphorus loading. The two methods operate via different mechanisms and may potentially supplement each other, especially when internal phosphorous loading is continuously high. However, their combined effects have so far not been elucidated. Here, we investigated the combined impact of the submerged macrophyte Vallisneria denseserrulata and a lanthanum-modified bentonite (Phoslock®) on water quality in a 12-week mesocosm experiment. The combined treatment led to stronger improvement of water quality and a more pronounced reduction of porewater soluble reactive phosphorus than each of the two measures. In the combined treatment, total porewater soluble reactive phosphorus in the top 10 cm sediment layers decreased by 78% compared with the control group without Phoslock® and submerged macrophytes. Besides, in the upper 0–1 cm sediment layer, mobile phosphorus was transformed into recalcitrant forms (e.g. the proportion of HCl–P increased to 64%), while in the deeper layers, (hydr)oxides-bound phosphorus species increased 17–28%. Phoslock®, however, reduced the clonal growth of V. denseserrulata by 35% of biomass (dry weight) and 27% of plant density. Our study indicated that Phoslock® and submerged macrophytes may complement each other in the early stage of lake restoration following external nutrient loading reduction in eutrophic lakes, potentially accelerating the restoration process, especially in those lakes where the internal phosphorus loading is high.
AB - Establishment of submerged macrophyte beds and application of chemical phosphorus inactivation are common lake restoration methods for reducing internal phosphorus loading. The two methods operate via different mechanisms and may potentially supplement each other, especially when internal phosphorous loading is continuously high. However, their combined effects have so far not been elucidated. Here, we investigated the combined impact of the submerged macrophyte Vallisneria denseserrulata and a lanthanum-modified bentonite (Phoslock®) on water quality in a 12-week mesocosm experiment. The combined treatment led to stronger improvement of water quality and a more pronounced reduction of porewater soluble reactive phosphorus than each of the two measures. In the combined treatment, total porewater soluble reactive phosphorus in the top 10 cm sediment layers decreased by 78% compared with the control group without Phoslock® and submerged macrophytes. Besides, in the upper 0–1 cm sediment layer, mobile phosphorus was transformed into recalcitrant forms (e.g. the proportion of HCl–P increased to 64%), while in the deeper layers, (hydr)oxides-bound phosphorus species increased 17–28%. Phoslock®, however, reduced the clonal growth of V. denseserrulata by 35% of biomass (dry weight) and 27% of plant density. Our study indicated that Phoslock® and submerged macrophytes may complement each other in the early stage of lake restoration following external nutrient loading reduction in eutrophic lakes, potentially accelerating the restoration process, especially in those lakes where the internal phosphorus loading is high.
KW - Eutrophication
KW - Phosphorus
KW - Restoration
KW - Sediments
UR - http://www.scopus.com/inward/record.url?scp=85101335518&partnerID=8YFLogxK
U2 - 10.1016/j.envpol.2021.116720
DO - 10.1016/j.envpol.2021.116720
M3 - Journal article
C2 - 33640814
AN - SCOPUS:85101335518
SN - 0269-7491
VL - 277
JO - Environmental Pollution
JF - Environmental Pollution
M1 - 116720
ER -