Biological Denitrification Using Slow-Release Carbon Source Composite Materials as Solid Carbon Source and Biofilm Carrier

Abstract

As lack of organic carbon source is a key problem for biological denitrification, hemp fiber, PBS, PLA and PE were selected as raw materials, then four kinds of slow-release carbon source composite materials were prepared by 35A-double-screw extruder and used for biological denitrification. Their performan- ces were detected through static and continuous experiments. The results showed that in the static experiments, release carbon abilities of HB20 and HB40 were both not good, their CODMnwere 5.42 and 12.83mg/L respectively; In the continuous experiments, NO3-N removal rate of HLE decreased from 57.9% to 13.1% within 30 days. HBE could cause a continuous release of dissolved organic compound. In the operation of 66 days, above 96.0% NO3-N was removed and NO2-N level was below 0.02mg/L when influent NO3-N =30.0mg/L and HRT=24h. HBE was the most suitable carbon source carrier material for biological denitrification.