移动床生物膜反应器用聚乙烯填料的改性研究

Modification of Polyethylene Biocarrier for Moving-Bed Biofilm Reactor

采用液相化学氧化和明胶表面接枝的改性方法对普通聚乙烯填料进行改性,利用正交实验找出最优的改性条件,并研究改性前后填料的表面特性、挂膜和废水处理等性能。结果表明,液相化学氧化最优的改性条件是80℃,4 h,n(HNO3)∶n(H2SO4)为1∶18,明胶接枝改性的最优条件是60℃,24 h,明胶质量浓度5 g/L。经过两种方法改性后填料表面的粗糙度及亲水性基团占比提高,液相氧化和明胶接枝改性的填料的挂膜时间分别缩短了26.92%和61.54%,挂膜量分别提高了55.18%和90.75%,两种改性填料对COD的去除率分别提高了13.92%和17.01%。因此填料的表面改性能显著提高其挂膜和水处理效果,其中明胶接枝改性填料表面有更为丰富的微生物群落,水处理效果更稳定。

In this work,polyethylene biocarriers were modified by chemical liquid-oxidation and gelatin graft treatments.The optimal modification condition was obtained by orthogonal experiments.The surface property,film hanging and wastewater treatment performance of the biocarriers before and after the modification were studied.Our results showed that the optimal modification condition for chemical liquid-oxidation was 80℃,4 h,and HNO 3∶H 2SO 4 molar ratio 1∶18,while the optimal condition by the gelatin graft treatment was 60℃,24 h,and gelatin concentration 5 g/L.The surface roughness and hydrophilic group proportion of the biocarriers both increased after the modification by the two methods.The biofilm-forming time of the biocarriers modified by chemical liquid-oxidation and gelatin graft treatments decreased by 26.92%and 61.54%,respectively,and the biofilm amount increased by 55.18%and 90.75%,respectively.The COD removal rates of the two modified biocarriers increased by 13.92%and 17.01%,respectively.Based on these results,we found that the surface modification of the filler could significantly improve the film-adhesion and water treatment performance,whereas the surface of gelatin-grafted biocarriers hosted more abundant microbial communities with more stable water treatment performance.