混盐条件下藻类生长特性及磷营养盐动力学分析

Analysis for growth characteristics and phosphorus nutrient dynamics of algae in mesohalinous water

选择天津滨海地区混盐水体,研究不同盐度下藻类演替及生长规律,并探究混盐条件下磷营养盐对藻类生长的影响,以Monod方程为理论基础,构建混盐条件下藻类生长—磷营养盐动力学模型,为混盐水体水华防治提供依据。结果表明:在盐度(以质量浓度计)<10 000mg/L的情况下,卵囊藻(Oocystissp)和铜绿微囊藻(Microcystis aeruginosa)为优势种;当盐度≥10 000mg/L时,铜绿微囊藻为优势种。盐度为10 000~20 000mg/L时,藻类适宜生长繁殖;当盐度<10 000mg/L或盐度>20 000mg/L时,藻类生长繁殖受到不同程度的抑制。当盐度为15 000mg/L的条件下,适宜藻类生长的磷营养盐(以磷计)为0.20~1.50mg/L;当磷营养盐为1.50mg/L时,比生长率最大。通过藻类生长—磷营养盐动力学分析,确定混盐条件下藻类最大比生长率为0.877d-1,半饱和常数为0.914mg/L。

Aiming at the mesohalinous water bodies in coastal region of Tianjin,the growth characteristics of algae in different salinities and phosphorus nutrient concentration were studied,and a dynamic model of algae growthphosphorus nutrient for mesohalinous water based on the theory of Monod equation was built.The research results showed that：when the salinity（calculated at mass concentration）was〈 10 000 mg/L,Oocystissp and Microcystis aeruginosa were predominant algae;when the salinity was≥10 000mg/L,Microcystus aeruginosa occupied absolutely dominant position.Algae growth was always active in condition of the salinity range from 10 000mg/L to 20 000mg/L.When the salinity was less than 10 000 mg/L or more than 20 000 mg/L,the algae growth was inhibited to some extent.The phosphorus nutrient concentration ranged from 0.20 mg/L to 1.50 mg/L was suitable for algae growth with salinity of 15 000mg/L.Algae growth reached the maximum while the phosphorus nutrient concentration（calculated by phosphorus）was 1.50 mg/L.Through the analysis of the dynamic model,the maximum specific growth rate of algae was 0.877d-1,and the semi-saturation constant was 0.914mg/L.