不同填料载体生物膜对微囊藻毒素的去除效果

Removal effect of microcystins by biofilm formed in different kinds of fillers

利用自行设计的生物膜培养装置,通过对4种不同填料载体进行连续曝气循环培养生物膜,对湖水中的溶解态微囊藻毒素(MCs)的去除作用进行了研究。结果表明,填料载体上生物膜从形成到稳定大约需要3周;生物膜形成后对MCs的去除效率由高到低的顺序是:颗粒活性炭柱>多密孔球型滤料柱>塑料悬浮填料柱>陶瓷滤球柱。在实验水质条件下,当水力停留时间(HRT)=5 h,进水MCs浓度为21.5～47.25μg/L时,颗粒活性炭、多密孔球型滤料柱对MCs的去除率最高可达100%,塑料悬浮填料柱对MC-LR和MC-RR的去除率分别为70%和88%。当HRT=2.5 h时,塑料悬浮填料柱对MC-RR的去除率为MC-LR的2倍。生物膜对MCs的降解效果随温度(5～20℃)和溶解氧的升高而增加。塑料悬浮填料作为合适的生物膜挂膜填料载体对水源水的生物预处理具有良好的应用前景。

The removal efficiency of dissolved microcystins（MCs） in lake water by biofilm with four differ- ent carriers was investigated. The results indicated that approximately three weeks were required for the develop- ment of biofilm to reach a steady-state. The removal efficiencies of MCs from high to low by the bioreactors with different carriers were as follows： granule activated carbon carrier 〉 porous sphere carrier 〉 plastic suspended carrier 〉 ceramics carrier. Under the experimental conditions of water quality and a hydraulic retention time （HRT） of 5 h, MCs from the influent （21.5-47.25μg/L） could be completely removed with granule activated carbon carrier and porous sphere carriers, while the removal rates of microcystin-LR and RR were 70% and 88% by suspension plastic carrier, respectively. When HRT was 2.5 h, the removal rate of microcystin-RR was 2 times higher than that of microcystin-LR by the plastic suspended carriers. The biodegradation rate of MCs was enhanced with increase of tempreture （from 5 to 20℃ ） and dissolve oxygen. The plastic suspended carriers can be used as appropriate biofilm carrier and will have a good application prospect in the pretreatment of source water.