贝、藻耦合对集约化养殖尾水的净化效果研究

Study on purification effect of shellfish and algae coupling on intensive aquaculture tailwater

为探讨贝、藻偶合方式对集约化养殖尾水的净化作用,研究分析了香港牡蛎(Crassostrea hongkongensis)和钝顶螺旋藻(Spirulina platensis)耦合对富含氮(N)、磷(P)营养盐的生物絮团养殖尾水的处理效果。实验共设置5组,小规格组(S)、中规格组(M)和大规格组(L)添加的牡蛎个体均质量分别为(50.99±7.01)、(100.25±8.87)和(148.81±15.61)g,阴性对照组(NC)只添加螺旋藻,空白对照组(BC)不添加牡蛎和螺旋藻,实验组中螺旋藻密度约为8×10^(5)个·mL^(−1),牡蛎生物量为3 kg·m^(−3)。记录牡蛎的成活率及生长情况,显微镜计数螺旋藻密度,测定水体氨氮(NH_(4)^(+)N)、亚硝酸盐(NO_(2)^(-)-N)、硝酸盐(NO_(3)^(-)-N)、活性磷酸盐(PO_(4)^(3-)-P)、总无机氮(TIN)、总氮(TN)、总磷(TP)、总悬浮物(TSS)等的浓度。结果显示,成活率S组>M组>L组,M组体质量增长率最高;NC组的螺旋藻密度最高[(1.30±0.25)×10^(7)个·mL^(−1)];M组能去除30.61%的TSS;NC组的TIN和PO_(4)^(3-)-P去除率最高,分别为89.29%和98.93%;M组的TN和TP去除率最高,分别为38.91%和55.10%。研究表明螺旋藻净化无机氮、无机磷效果明显,牡蛎能有效摄食水体中的螺旋藻,将个体均质量(100.25±8.87)g的牡蛎与螺旋藻耦合,对去除养殖尾水中TN、TP和TSS的效果最佳。

To explore the purification effect of shellfish and algae coupling on intensive aquaculture tailwater,we analyzed the coupling effects of oyster(Crassostrea hongkongensis)and microalgae(Spirulina platensis)on tailwater treatment of biological flocs which are rich in nitrogen and phosphorus nutrients.A total of five groups were set up.The average mass of oysters added to the small(S),medium(M)and large(L)size groups was(50.99±7.01),(100.25±8.87)and(148.81±15.61)g,respectively.The negative control group(NC)was only added with spirulina,and the blank control group(BC)was not added with oysters and spirulina.The density of spirulina was about 8×10^(5)cell·mL^(−1)and oyster biomass was 3 kg·m^(−3).The survival rate and growth of oysters were recorded,and the cell density of spirulina in water was counted under a microscope.The concentrations of NH_(4)^(+)-N,NO_(2)^(-)-N,NO_(3)^(-)-N,PO_(4)^(3-)-P,TIN,TN,TP and TSS in water were detected.The results show that the survival rate of oysters in the experimental group followed a descending order of S>M>L.The highest rate of weight gain was observed in Group M.The highest density of spirulina was(1.30±0.25)×10^(7)cells·mL^(−1)in Group NC.The highest TSS removal rate in Group M was 30.61%.The NC group had the highest TIN and PO_(4)^(3-)-P removal rates of 89.29%and 98.93%,respectively.Group M had the highest TN and TP removal rates of 38.91%and 55.10%,respectively.The results suggest that spirulina has a significant effect on purifying inorganic nitrogen and phosphorus.Oysters can feed on spirulina in water effectively.Coupling oysters of average mass of(100.25±8.87)g with spirulina has the best effect on removing TN,TP and TSS from aquaculture tail water.