作 者：
温珊珊;张寒野;何文辉;张饮江;徐姗楠;何培民
单 位：
上海海洋大学水产与生命学院;中国水产科学研究院东海水产研究所
摘 要：
以真江蓠(Gracilaria asiatica)为实验材料,在实验室水平上测定了真江蓠培养密度对NH4-N去除效率和吸收速率的影响,比较了真江蓠在氮半饥饿和氮饱和状态下的氨氮吸收动力学特征以及不同起始浓度NH4-N对其吸收速率的影响。结果表明:真江蓠密度为2~24g.L-1时,5h内随着藻体密度增大和实验时间延长,真江蓠去氨氮能力也增强。当藻体密度为24g.L-1时,真江蓠在5h内去除氨氮效率最高,达到99.77%。各种藻体密度在起始阶段保持较高吸收速率(30~41μmol.g-1.h-1),随后藻体密度与吸收速率呈反比关系,其最低藻体密度组(2g.L-1)在3h和5h吸收速率最大,分别为28.33μmol.g-1.h-1和18.85μmol.g-1.h-1。在起始浓度梯度实验中,氮半饥饿和氮饱和真江蓠吸收氨氮的最大吸收速率和半饱和常数在1h均达到最高值,分别为116.47、159.40μmol.g-1.h-1和439.70、913.61μmol.L-1。之后随着培养时间的延长而降低。氮半饥饿和氮饱和真江蓠对NH4-N的吸收差别不显著;当氨氮浓度为300~500μmol.L-1时,氮半饥饿的真江蓠在起始1h内有一个快速吸收阶段(40.7~102.1μmol.g-1.h-1),吸收速率与NH4-N浓度几乎成正比,此时不符合米氏动力学饱和方程,而在低N浓度下(100~200μmol.L-1),藻体对NH4-N的吸收则没有出现这种现象;随着培养时间延长,直到NH4-N浓度达到一定限度时,吸收速率可达到一极大值而符合米氏动力学饱和方程。该研究结果为大规模栽培真江蓠净化水体和生态修复提供了理论依据。
译 名：
Study on NH4-N removing efficiency and kinetics in Gracilaria asiatica
作 者：
WEN Shan-shan1, ZHANG Han-ye2,HE Wen-hui1,ZHANG Yin-jiang1,XU Shan-nan1,HE Pei-min1(1.College of Fisheries and Life,Shanghai Ocean University,Shanghai 200090,China; 2.East China Sea Fisheries Institute,Chinese Academy of Fishery Sciences,Shanghai 200090,China)
关键词：
Gracilaria asiatica;NH4-N;uptake kinetics;bioremediation
摘 要：
Eutrophication caused by mariculture has become a serious environmental problem.Seaweeds would play an important role for decreasing marine eutrophication due to the cost saving,low sensitivity to environmental and impurity factors,the possible contaminant recovery from the biomaterial and its elevated adsorption capacity.Seaweeds are able to Absorb large quantities of nitrogen,phosphorus and carbon dioxide,produce large quantities of oxygen,and have excellent effect on decreasing eutrophication.In this paper,ammonium nitrogen removing efficiency and Absorption rate by Gracilaria asiatica with different culture densities were determined,and dynamics character of ammonium nitrogen uptaking at N-limited and the N-replete situation and the effect of different initial concentration of ammonium nitrogen on Absorption rate were studied.Gracilaria asiatica was collected at Xiangshan harbor,Zhejiang province,southern China,and cultivated in the laboratory.Samples of the alga were maintained in a flask with 250 mL seawater of 21 salinity.The alga were cultured in culture boxes at(20±1) ℃,under 60 μmol·m-2·s-1 illumination,and on 12 h∶12 h light/dark cycle.The result showed that the ability of ammonium nitrogen removing was enhanced by seaweed culture density(in 2-24 g·L-1) and experiment time(in 5 hours) increasing.The highest efficiency of ammonium nitrogen removing with highest density(24 g·L-1) of G.asiatica was up to 99.77% after 5 hours.Ammonium nitrogen concentration declined from 300 μmol·L-1 to zero.The ammonium nitrogen removing efficiency with lowest density(2 g·L-1) was only 20%.Higher ammonium nitrogen Absorption rate(30-41 μmol·g-1·h-1) was kept in different density groups during initial culture period,especially in 16 g·L-1 density group,then decreased with density increase.The maximum uptake rates reached as high as 28.33 μmol·g-1·h-1 and 18.85 μmol·g-1·h-1 at 3 h and 5 h,respectively,in 2 g·L-1 minimum density group.The lowest ammonium nitrogen uptake rate of 11.70 μmol·g-1·h-1 and 1.90 μmol·g-1·h-1 were obtained at 3 h and 5 h with the highest density group(24 g·L-1).In initial concentration experiment,maximum uptake rates(Vmax) and half-saturation constant(Km) of G.asiatica at N-limited and the N-replete situation reached the highest value,116.47,159.40 μmol·g-1·h-1 and 439.70,913.61 μmol·L-1 in the first hour,then they declined from 24.29,23.22 μmol·g-1·h-1 and 166.87,255.30 μmol·L-1 with culture prolonging from 1 h to 5 h.In initial concentration experiment,ammonium nitrogen removing efficiency were increased with initial concentration reduced in the range of 100-300 μmol·L-1,especially with lowest ammonium nitrogen concentration(100 μmol·L-1).Ammonium nitrogen removing efficiency kept in 56.7%-67.4% with 300-500 μmol·L-1 of ammonium nitrogen concentration.There was no difference for ammonium nitrogen Absorption of G.asiatica at between N-limited and the N-replete situation.Within 300-500 μmol·L-1 of ammonium nitrogen concentration,a fast Absorption rate of G.asiatica at N-half hungry situation presented in the first stage(40.7-102.1 μmol·g-1·h-1),and almost had a positive relation with concentration,which was not fit the Micheal dynamics saturation equations.But,within 100-200 μmol·L-1 of ammonium nitrogen concentration,the uptake rates of G.asiatica were as low as 17.8-40.8 μmol·g-1·h-1.When the concentration decreased in some limited range,the Absorption rate reached the maximum and fit the Micheal dynamics saturation equations.It would provide important theory data for cleaning water and bioremediation by cultivating G.asiatica,and large-scale cultivation of G.asiatica could be a good solution to the problem of eutrophication due to their capability of removing nutrients.
