复合微生态制剂对循环水养殖系统老化生物滤池的在线修复作用

Online remediation of aged biofilters in a recirculating aquaculture system by compound probitics

为解决海水循环水养殖系统(recirculating aquaculture system,RAS)内老化生物滤池的在线修复问题,选用一种复合微生态制剂连续15 d向养殖池及其老化的生物滤池泼洒,以正常生物滤池作为对照,通过监测生物滤池入水口和出水口的水质理化指标及异养菌和弧菌数量变化情况,判断老化生物滤池的修复效果。结果表明:添加微生态制剂6 d后,老化生物滤池净化能力开始修复,15 d时对亚硝酸盐、氨氮去除率分别从修复前的28.34%、27.28%提高至47.24%、46.07%,且比对照组去除率略有提高,化学需氧量COD Mn(5.75 mg/L)较修复前(7.28 mg/L)显著降低21.70%(P<0.05),且显著低于对照组(P<0.05);修复后整个养殖水体中,亚硝酸盐、氨氮、COD Mn水平下降明显(P<0.05),水体中异养菌数量增多,弧菌数量下降,弧菌占总菌比例显著下降(P<0.05)。研究表明,利用复合微生态制剂可实现对老化生物滤池的在线修复,使生物滤池的水质净化能力快速得到恢复。

In order to solve the problem of on-line remediation of aged biofilters within a mariculture recirculating system(RAS),compound probiotics were splashed into the culture tank and aged biofilters periodically to judge the remediation effect on the aged biofilter according to the recovery of removal efficiency of nitrite,ammonia nitrogen and the recovery of microorganisms in the biofilter through monitoring the physicochemical indices of enter&effluent water and the changes in the numbers of heterotrophic bacteria and Vibrios.The results showed that the purification capacity of aged biofilters began to be reconstituted 6 days after addition of compound probiotics,and the removal efficiency of nitrite and ammonia nitrogen was found to be increased from 28.34%and 27.28%to 47.24%and 46.07%,respectively,15 days after administration,and 10%-20%lower than those in the control.The COD Mn of recovered biofilter was 21.70%lower than that of aged biofilter and that in the control(P<0.05),and the levels of nitrite,ammonia and COD Mn in the whole culture system were decreased significantly(P<0.05).The abundance of heterotrophic bacteria was shown to be increased and that of Vibrio to be decreased in the whole system,with decrease in the proportion of Vibrios(P<0.05).The findings prove that on-line remediation of aged biofilters can be performed by using compound probiotics,ad that the water quality purification capacity of the biofilters can be quickly recovered,which provides a technical guarantee for the high-efficiency operation of mariculture systems and also plays a driving role for the application of compound probiotics in mariculture systems and the green health development of the mariculture industries.