不同添加量的聚-β-羟基丁酸酯作为生物絮凝缓释碳源的应用效果

The effect of different addition amounts of poly-β-hydroxybutyrate acid(PHB)as a slow-release carbon source in biological flocculation

为探究聚-β-羟基丁酸酯作为生物絮凝系统缓释碳源的适宜添加比例。分别向80 g/m^(3)(A组)、200 g/m^(3)(B组)、320 g/m^(3)(C组)3个试验组添加聚-β-羟基丁酸酯(PHB),进行为期48 d的罗非鱼养殖试验,每4 d进行一次水质监测,试验结束时检测鱼苗生长情况,取生物絮团进行营养指标检测,将PHB称重后进行扫描电镜及红外光谱检测。结果显示:随着PHB添加量的提高,各组总氨氮(TAN)峰值均逐渐降低,硝酸盐氮(NO-3-N)积累均提高;试验后期,A组可以稳定地将系统碳氮比(DOC/TN)维持在15以上的较高水平;3个试验组中不同PHB添加量对罗非鱼存活率、增重率不产生显著影响(P>0.05);饲料系数C组显著小于A组和B组(P<0.05);不同添加量的PHB作为系统碳源降解损耗差异显著(P<0.05),随着PHB添加量的提高,降解损耗量越高,降解破损程度越低。研究表明,80 g/m^(3)的PHB添加量能在养殖期间维持系统碳氮比在15以上的较高水平,可作为PHB用作生物絮凝系统缓释碳源的适宜添加比例。

In order to explore the appropriate addition ratio of poly-β-hydroxybutyrate acid(PHB)as a slow-release carbon source in biofloc systems,PHB was added to 3 trial groups respectively at the ratio of 80 g/m^(3)(group A),200 g/m^(3)(group B)and 320 g/m^(3)(group C),and a 48-day breeding experiment was conducted.Water quality monitoring was carried out every 4 days.At the end of the experiment,the growth of the fries was detected,the flocs were taken for nutrient index detection,and the PHB was weighed for scanning electron microscopy and infrared pectroscopy.The research results showed that with the increase of PHB addition,for all groups,the peak value of total ammonia nitrogen(TAN)gradually decreased,and the accumulation level of nitrate nitrogen(NO-3-N)increased.In the later stage of the experiment,group A could stably maintain the system DOC/TN at a level above 15.Different PHB additions had no significant effect on the survival rate and weight gain rate of the cultured tilapia(P>0.05),and the feed coefficient of group C was significantly lower than that of group A and group B(P<0.05).Different addition amounts of PHB as a system carbon source showed significant differences in degradation loss(P<0.05).With the increase of PHB addition,the higher the degradation loss,the lower the degree of surface degradation and damage.In summary,a PHB addition of 80 g/m^(3) could maintain a high level of system C/N above 15 during the breeding period,and could be used as a suitable addition ratio for PHB as a slow-release carbon source in biological flocculation systems.