固定化硝化菌在养鱼废水处理中的应用

为研究海水养殖系统中关键性的硝化过程,在60L的水族缸富集驯化海洋硝化细菌,并通过固定化对海水循环养殖系统的废水进行生物脱氮.模拟养殖水体环境条件,通过不断提高氨氮质量浓度对海洋硝化细菌直接进行富集驯化,46d后,氨氧化速率和亚硝酸氧化速率均在8mg/(L·d)以上.以聚乙烯醇(PVA)大球、小球及颗粒活性炭为载体,对驯化好的硝化细菌进行15d的吸附挂膜,采取固定床生物反应器连续运行,进行养殖废水的生物脱氮试验.停留时间为1h,进水氨氮质量浓度小于0.6mg/L时,氨氮降解效率可达100%.进水氨氮质量浓度为0.5mg/L,停留时间在10～90min时,最佳停留时间的测定结果表明:活性炭柱、PVA小球柱、PVA大球柱最佳停留时间分别为15min、18min和22min左右,此时氨氮去除速率依次为70g/(m3·d)、58g/(m3·d)和48g/(m3·d).该研究成果有利于封闭式循环水养殖系统的发展.

Removal of ammonium-N from marine recirculating aquaculture by immobilized nitrifiers

Marine nitrobacters were enrichmented,acclimated and used to denitrificate of marine recirculating aquaculture by immobilization in an aquarium of 60 L.After 46 d,the ammonia oxidation rate and the nitrite oxidation rate were both over 8 mg/(L·d) by adjusting the ammonium concentration in appropriate condition.An adsorption experiment was carried out for 15 d with two kinds of PVA beads and the activated carbon beads filled in three plastic columns respectively.And experiments to evaluate the efficiency nitrification of three fixed packed bed column were conducted.Results show that with a hydraulic retention(HRT) of 1 h and the influent ammonia concentration less than 0.6 mg/L,all the three reactors can achieve the efficiency of 100%.When HRT is set in the range of 10-90 min,the highest ammonia-N removal rates of 70 g/(m3· d) ,58 g/(m3·d) ,and 48 g/(m3·d) are figured out for the activated carbon,the PVA beads(2 mm) and the PVA beads(4 mm) reactors respectively with the optimal HRT of 15 min,18 min,and 22 min.