极北海带对氮、磷吸收和砷、镉、铅吸附的研究

极北海带(Laminaria hyperborea)分布于大西洋东北海域,有很高的经济和生态价值,有望成为我国海藻资源增值的对象。本研究通过分析极北海带在不同温度下对N、P营养盐的吸收,以及对不同重金属离子的吸附,研究其对富营养化和重金属的去除能力。结果显示,1)温度为9℃~13℃时,极北海带对N、P的吸收率均最高,其中72 h后其对P的吸收率达到了95%~98%,对氨氮的吸收率为96%,对硝酸氮的吸收率约为42%,表明其对N、P有显著的去除作用。2)极北海带对As5+的富集量为168.33 mg/kg,藻体表面和内部As5+含量无显著差异,分别占藻体As5+总量的55%和45%,As5+处理6 d后极北海带的相对生长速率为–0.92%/d,极北海带生长不正常。极北海带对Cd2+的吸附量为15 mg/kg,且91%的Cd2+位于藻体表面,仅9%的Cd2+位于藻体内部,相对生长速率为5.78%/d,说明其对极北海带生长有抑制。极北海带对Pb2+的吸附量为320 mg/kg,其中96.5%的Pb2+被吸附于藻体表面,3.5%的Pb2+位于藻体内部,其相对生长速率为6.73%/d,表明Pb2+对极北海带的生长无显著影响。

Study on the Assimilation of Nitrogen and Phosphorus and on the Sorption of Heavy Metals in Laminaria hyperborea

Laminaria hyperborea is an economically and ecologically important kelp.It can grow lushly in the subtidal zone and from the seaweed forest,playing a significant ecological function.In this study,the absorption rates of nitrogen and phosphorus of L.hyperborea was determined at different temperatures(5℃,9℃,13℃,17℃),as well as relative growth rate(RGR)and accumulation of selected heavy metal ions(arsenic ions As5+,cadmium ions Cd2+,lead ions Pb2+),aiming to evaluate whether L.hyperborea is a potentially feasible candidate species for marine bioremediation.The main results are as follows:(1)the experimental specimens illustrated maximum absorption rates of nitrogen and phosphorus at 9℃~13℃after 72 h.The maximum absorption rates of phosphorus,ammonia nitrogen and nitrogen nitrate were 95%~98%,96%and 42%respectively,indicating that the removal of nitrogen nitrate,ammonia nitrogen,and phosphorus by L.hyperborea from seawater is significant.(2)The total arsenic ions content accumulated in the L.hyperborea was 168.33 mg/kg,there was no significant difference between the surface(55%)and inner(45%)of the algae;the relative growth rate was–0.92%/d when L.hyperborea were treated with arsenic ions for 6 days.The total cadmium ions content accumulated in L.hyperborea was 15 mg/kg,and the surface content(91%)was significantly higher compared to the inner content(9%);the relative growth rate of those individuals who were treated with Cd2+enriched solution for 6 days was 5.78%/d(lower than the control).The total lead ion content accumulated in the L.hyperborea was 320 mg/kg.The surface concentration(96.5%)was significantly higher compared to that of the inner concentration(3.5%)of the algae;the relative growth rate of those individuals who were treated in Pb2+enriched solution for 6 days was 6.73%/d,which had no significant difference with control condition.The results suggested L.hyperborea could be an ideal candidate in marine bioremediation.