| 摘要: |
| 沉水植物光合作用形成的微环境有利于水体中钙和磷形成CaCO3-P共沉淀，从而将水体中的磷永久性去除，避免植物腐烂后的二次污染.但不同的沉水植物种类形成CaCO3-P共沉淀的能力不同.本文以沉水植物菹草（Potamogeton crispus L.）和金鱼藻（Ceratophyllum demersum L.）为实验对象，研究水体中添加钙离子（0、100 mg/L）对水体磷（磷浓度：0、0.2、2 mg/L）的去除和植物富集磷的差异，并通过植物灰分磷的组分分析，聚焦植物钙磷的变化，为生态修复中沉水植物的选择提供理论依据.结果表明：（1）菹草和金鱼藻体系中总磷（TP）和溶解性反应磷（SRP）浓度显著下降，添加钙离子使降幅升高，且菹草体系中水体TP和SRP降幅均高于金鱼藻TP和SRP降幅；（2）菹草的干重全磷在高磷低钙（2-0）水平最高，灰分总磷在高磷高钙（2-100）水平最高，而金鱼藻干重全磷在高磷高钙（2-100）水平最高，灰分总磷在中等磷低钙（0.2-0）水平最高；（3）在2 mg/L的磷浓度下，添加钙离子使菹草的钙磷（HCl-P）和水溶性磷（H2O-P）含量升高，有机磷（NaOH-P）含量降低，结果使灰分总磷含量升高，而金鱼藻NaOH-P升高，HCl-P和H2O-P含量均降低，结果使灰分总磷降低.这表明菹草通过提高吸附性磷和钙磷含量增强磷的富集，而金鱼藻则只显著升高了灰分中有机磷的含量.显然，水体富营养化背景下，相较于金鱼藻，菹草具有更强的形成CaCO3-P共沉淀的能力，具备竞争优势. |
| 关键词: 沉水植物 钙 磷 磷富集 灰分磷 钙磷 菹草 金鱼藻 |
| DOI：10.18307/2020.0210 |
| 分类号: |
| 基金项目:国家自然科学基金项目（31670367）资助. |
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| Effect of calcium addition on phosphorus enrichment capacity of two submerged plants (Potamogeton crispus L. and Ceratophyllum demersum L.)in water bodies |
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CHEN Qi, WANG Heyun
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Key Laboratory of Ecological Remediation of Lakes and Rivers and Algal Utilization of Hubei Province, School of Civil and Environment, Hubei University of Technology, Wuhan 430068, P. R. China
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| Abstract: |
| The micro-environment formed by submerged plant photosynthesis is conducive to the formation of CaCO3-P from co-precipitation of calcium and phosphorus in water, thereby permanently removing phosphorus from water and avoiding secondary pollution after plant decomposition. However, CaCO3-P co-precipitation has obvious specific differences. Two submerged species, Potamogeton crispus L. and Ceratophyllum demersum L., were chosen to study the calcium addition (0,100 mg/L) on phosphorus removal and enrichment capacity of the plants under different phosphorus concentration (0, 0.2, 2 mg/L). The phosphorus fraction of plant ashes and the change of HCl-P were analyzed in order to help to select the submerged plants for ecological restoration projects. The results revealed that:(1) Both P. crispus L. and C. demersum L. could effectively reduce the concentration of total phosphorus (TP) and soluble reactive phosphorus (SRP). The calcium addition increased the decrease amplitude and P. crispus L. showed higher decrease amplitude than C. demersum L.; (2) For P. crispus L., the plant phosphorus content (dry weight) was the highest under the condition of high phosphorus and low calcium (2-0), while ash TP was under the condition of high phosphorus and high calcium (2-100). For C. demersum L., the plant phosphorus content (dry weight) was the highest under the condition of high phosphorus and high calcium (2-100), while ash TP was under the condition of medium phosphorus and low calcium (0.2-0);(3)When the phosphorus concentration was 2 mg/L, for P. crispus L. the calcium addition increased the content of HCl-P and H2O-P, while decreased NaOH-P, resulting in the increase of the plant ash TP. For C. demersum L., the calcium addition increased the content of NaOH-P, while decreased HCl-P and H2O-P contents, resulting in the decrease of the plant ash TP. This suggests that P. crispus L. enhanced phosphorus enrichment by increasing the content of adsorptive phosphorus and calcium phosphorus, while the C. demersum L. only significantly increased the content of organic phosphorus in the ash. Obviously, P. crispus L. has a competitive advantage than C. demersum L. because of stronger ability to form co-precipitation of CaCO3-P under eutrophical water. |
| Key words: Submerged plant calcium phosphorus phosphorus enrichment ash phosphorus HCl-P Potamogeton crispus L. Ceratophyllum demersum L. |
