摘要
为评估水产养殖中小球藻在调控水体氨氮(NH_(4)^(+)-N)和亚硝酸盐氮(NO_(2)^(-)-N)的应用前景,实验以普通小球藻为对象,饲料废水为培养液,首先检测了曝气、光照、光照+曝气条件下普通小球藻细胞密度及水体中NH_(4)^(+)-N和NO_(2)^(-)-N的时间变化规律,其次分析了时间(X1)、光照强度(X2)或初始藻密度(X3)对2种氮盐去除率(Y)的影响,最后评估了普通小球藻去除水体中NH_(4)^(+)-N、NO_(2)^(-)-N和NO_(3)^(-)-N的效果,并解析了普通小球藻同化水体NO_(2)^(-)-N的潜在途径。结果显示,普通小球藻在适宜的光照条件下具有极佳的氮盐去除能力,其在18000 lx时对NH_(4)^(+)-N去除率高达96.23%,在9000 lx时对NO_(2)^(-)-N去除率高达99.19%;初始藻密度在2.5×105个/mL时对NH_(4)^(+)-N、NO_(2)^(-)-N去除率最高,分别为94.92%和99.05%。氮盐去除率与处理时间和光照强度的回归方程:YNH_(4)^(+)-N=1.189X1+5.79×10-4X2+24.158(R^(2)=0.664),YNO_(2)^(-)-N=1.562X1+1.909×10-3X2-26.078(R^(2)=0.762);氮盐去除率与处理时间和初始藻密度的回归方程为:YNH_(4)^(+)-N=0.888X1+1.02×10-5X3+32.555(R^(2)=0.408),YNO_(2)^(-)-N=1.746X1+1.64×10-5X3-17.250(R^(2)=0.613)。普通小球藻去除氮盐顺序为NH_(4)^(+)-N>NO_(3)^(-)-N>NO_(2)^(-)-N;NH_(4)^(+)-N同化阶段普通小球藻亚硝酸盐还原酶活性显著低于NO_(2)^(-)-N同化阶段。研究表明,普通小球藻能显著降低水体NH_(4)^(+)-N与NO_(2)^(-)-N含量,NO_(2)^(-)-N可能是由藻细胞内亚硝酸盐还原酶还原成NH_(4)^(+)-N而被普通小球藻同化吸收。该研究结果可为养殖水体原位生物修复提供科学依据。
Since the non-ionic ammonia and ionic ammonia can be converted into each other,in aquaculture,ammonia nitrogen(NH_(4)^(+)-N)and nitrite nitrogen(NO_(2)^(−)-N)are the key factors that affect the growth and development of aquatic animals.Therefore,the removal of NH_(4)^(+)-N and NO_(2)^(−)-N in aquaculture water is of great significance to ensure the health of aquaculture animals.As we all know,microorganisms and algae play important roles in maintaining the ecological balance of aquaculture ponds.It has been proved that Chlorella had the ability of purifying aquaculture water,with different Chlorella species different removal efficiency on NH_(4)^(+)-N and NO_(2)^(−)-N.Chlorella vulgaris is widely used in aquaculture,however,we know little about the removal effect on nitrogen nutrient especially NO_(2)^(−)-N by C.vulgaris.Given the shortage of effective ecological control measures in aquaculture,it is of great significance to illustrate the removal effect of NH_(4)^(+)-N and NO_(2)^(−)-N by C.vulgaris and related influencing factors.Aiming to evaluate the application prospect of C.vulgaris in purifying NH_(4)^(+)-N and NO_(2)^(−)-N in water,in the present study,C.vulgaris was taken as the research object and feed wastewater was taken as the culture medium.We firstly detected the cell density of C.vulgaris and the temporal variations of NH_(4)^(+)-N and NO_(2)^(−)-N in water under aeration,light,combined light and aeration conditions.Then we analyzed the effects of time(X1),light intensity(X2)or initial C.vulgaris density(X3)on the removal rates of NH_(4)^(+)-N and NO_(2)^(−)-N(Y).Finally,we evaluated the removal efficiency of NH_(4)^(+)-N,NO_(2)^(−)-N and NO_(3)^(−)-N from water by C.vulgaris,and we analyzed the potential pathway of NO_(2)^(−)-N assimilation by C.vulgaris.The results showed that C.vulgaris could remove NH_(4)^(+)-N,NO_(2)^(−)-N and NO_(3)^(−)-N significantly under suitable light conditions.The NH_(4)^(+)-N removal rate reached up to at 18000 lx(96.23%),and NO_(2)^(−)-N removal rate reached up to 99.19%at 9000 lx.The initial density of C.vulgaris at 2.5×105 cells/mL had the highest removal rates for NH_(4)^(+)-N and NO_(2)^(−)-N,accounting 94.92%and 99.05%,respectively.The regression equation of NH_(4)^(+)-N and NO_(2)^(−)-N removal rates with treatment time and light intensity was as follows:YNH_(4)^(+)-N=1.189X1+5.79×10−4X2+24.158(R^(2)=0.664),YNO_(2)^(−)-N=1.562X1+1.909×10−3X2−26.078(R^(2)=0.762).The regression equation of NH_(4)^(+)-N and NO_(2)^(−)-N removal rates with treatment time and initial C.vulgaris density was as follows:YNH_(4)^(+)-N=0.888X1+1.02×10−5X3+32.555(R^(2)=0.408),YNO_(2)^(−)-N=1.746X1+1.64×10−5X3−17.250(R^(2)=0.613).The order of nitrogen removal by C.vulgaris was NH_(4)^(+)-N>NO_(3)^(−)-N>NO_(2)^(−)-N,and the activity of nitrite reductase in C.vulgaris at NH_(4)^(+)-N decline stage was significantly lower than that at NO_(2)^(−)-N decline stage.In conclusion,C.vulgaris can significantly reduce the contents of NH_(4)^(+)-N and NO_(2)^(−)-N in water,and NO_(2)^(−)-N may be reduced to NH_(4)^(+)-N by intracellular nitrite reductase and assimilated by C.vulgaris.These results provide scientific basis for in-situ bioremediation of aquaculture waters.
作者
沈雷
高建操
聂志娟
郑兆伟
胡佳雯
邵乃麟
孙毅
徐钢春
SHEN Lei;GAO Jiancao;NIE Zhijuan;ZHENG Zhaowei;HU Jiawen;SHAO Nailin;SUN Yi;XU Gangchun(College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China;Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi 214081,China;Wuxi Fishery College,Nanjing Agricultural University,Wuxi 214081,China)
出处
《水产学报》
CAS
CSCD
北大核心
2024年第2期92-105,共14页
Journal of Fisheries of China
基金
国家重点研发计划(2019YFD0900301)
中国水产科学研究院基本科研业务费(2021XT0701)。
关键词
普通小球藻
氨氮
亚硝酸盐氮
同化途径
亚硝酸盐还原酶
Chlorella vulgaris
ammonia nitrogen
nitrite nitrogen
assimilation pathway
nitrite reductase
