Effects of Ammonium Nitrogen at Different Concentrations on Hybrid Duckweed Growth and Its Zinc Enrichment Capability
Zhang Yan
Yan Yue
Dong Hongyun
Wang Nana
Qi Gaoxiang
Li Ying
Liu Hongyuan
Wang Yanjun
Li Xinhua
Wang Yanqin
Abstract：As a high-quality raw material of renewable energy,duckweed culture and its wastewater re-mediation capability are currently the research focus.In this study,the hybrid duckweed from the cross of Lemna minor and Lemnaturionifera was used as an experimental plant,and six treatments were set with zinc concentrations at 3 and 6 mg·L-1 and NH4-N concentrations at 0,21.5 and 43.0 mg·L-1 to study the effects of adding different concentrations of ammonium nitrogen(NH4+-N)on the growth and Zn enrichment of duck-weed under sufficient nitrogen source.The results showed that under the conditions of Zn,duckweed growth could be limited but its Zn enrichment capability could be promoted when without NH4+-N addition,while it was opposite when with NH4+-N addition.Under NH4+-N addition,the maximum relative growth rate of duck-weed under the treatment with 3.0 mg·L-1 Zn was(0.246±0.015)d-1,and that under the treatment with 6.0 mg·L-1 Zn was(0.194±0.012)d-1.Under the treatment with 6.0 mg·g-1 Zn and without NH4-N addition,the maximum enrichment amount of Zn by duckweed was(8.458±0.444)mg·g-1,but the Zn enrichment by duckweed in the other treatments decreased.The addition of NH4+-N affecting the growth and Zn enrichment capability of duckweed was further confirmed by the Scanning Electron Microscope with Energy Dispersive X-Ray Analysis(SEM-EDX).The results of this study indicated that NH4-N could alleviate the damage of Zn to duckweed growth but inhibit its Zn enrichment capability under the condition of sufficient nitrogen source.Hence,the hybrid duckweed could bioaccumulate Zn effectively in the condition of sufficient nitrogen source,however,the addition of NH4+-N could significantly affect its Zn enrichment capacity.
Keywords：DuckweedPhytoremediationZinc enrichmentAmmonium nitrogenRelative growth rateEnrichment coefficientTolerance index
Publication Date：2025-06-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：11( 100-110 )