College of Life and Environmental Science, Wenzhou University, Wenzhou, 325035, Zhejiang, People's Republic of China.
National & Local Joint Engineering Research Center for Ecological Treatment Technology of Urban Water Pollution, Wenzhou University, Wenzhou, People's Republic of China.
Environ Sci Pollut Res Int. 2022 Jul;29(32):48748-48758. doi: 10.1007/s11356-021-18439-6. Epub 2022 Feb 24.
The nutrient ratio in wastewater discharge has a variety of ecological impacts on aquatic ecosystems. Plant species richness and identity (the presence of certain species in the community) affected the nitrogen (N), phosphorus (P), and potassium (K) removal efficiencies in constructed wetlands (CWs). However, the effects on the ratios of N/P/K are still unknown. This study conducted microcosms simulating floating CWs to explore the effects on these nutrient removal efficiencies and ratios. Results showed that (1) the presence of Canna indica decreased but the presence of Arundo donax increased effluent P and K concentrations, plant richness had no effect on effluent nutrients concentrations; (2) plant species richness only decreased the effluent P:K ratio but no effect on other effluent nutrient ratios; (3) the presence of C. indica increased but the presence of A. donax decreased effluent N:P and N:K ratios; (4) the presence of C. indica increased plant N, P, K pools through increasing plant biomass but the presence of A. donax decreased plant N, P, K pools through decreasing plant biomass. Overall, species identity surpassed species richness in affecting effluent nutrient concentrations and ratios. Assembling proper species composition could decrease effluent P and K concentrations and regulate effluent N/P/K ratios.
废水中的养分比例对水生生态系统有多种生态影响。植物物种丰富度和身份（群落中某些物种的存在）影响人工湿地（CWs）中的氮（N）、磷（P）和钾（K）去除效率。然而，对于 N/P/K 比例的影响尚不清楚。本研究通过微宇宙模拟浮床 CWs 来探索这些养分去除效率和比例的影响。结果表明：（1）美人蕉的存在降低了但芦竹的存在增加了出水 P 和 K 浓度，植物丰富度对出水养分浓度没有影响；（2）植物物种丰富度仅降低了出水 P:K 比，但对其他出水养分比没有影响；（3）美人蕉的存在增加了，但芦竹的存在降低了出水 N:P 和 N:K 比；（4）美人蕉通过增加植物生物量增加了植物 N、P、K 库，但芦竹通过减少植物生物量降低了植物 N、P、K 库。总的来说，物种身份比物种丰富度更能影响出水养分浓度和比例。组装适当的物种组成可以降低出水 P 和 K 浓度并调节出水 N/P/K 比。
