Effects of Biofilm Carriers on Start-Up and the Adaptability to the Shock Load of Bioreactors of Micro-Contamination River Water

Abstract:

In order to compare the start-up period and the adaptability to the shock load of two lab-scale bioreactors of two kinds of materials employed as biofilm carrier inoculated sediments of river，the biofilm forming rate and the efficiencies of treating polluted river water at four different hydraulic retention time（HRT） were studied. The experimental results showed the startup speed of bioreactor filled with elasticity plastic was more rapid compared to the bioreactor filled with suspend packing，reducing the start-up period for its earlier maturation in removing NH4^{+-N；In the steady running stage，the removal efficiencies of NH4+-N and CODMn in two bioreactors both reached 97% and 80% respectively；The average removal efficiency of ammonia nitrogen dropped from 98.18%，98.76% to 78.32%，87.63% respectively，the average removal efficiency of CODMn dropped from 84.52%，83.69% to 60.90%，64.71% respectively with hydraulic retention time（HRT） shortened from 14.80 h to 7.99 h；The biofilm attaching on elasticity plastic filler has higher activity at four different hydraulic retention time（HRT） and the examination showed more impacted structure within biofilm attaching on elasticity plastic than the biofilm attaching on suspend packing at hydraulic retention time of 7.99 h；which showed the startup speed of elasticity plastic was more rapid compared to suspend packing and elasticity plastic filler had a stronger resistance to impact load than suspend packing in river water treatment.}