Keywords: nitrate removal, denitrification, groundwater, BDP, biodegradable polymers, biofilms, fixed-bed reactors
Nitrate removal from groundwater using biodegradable polymers as carbon source and biofilm support
A new kind of biodegradable polymer, PBS, was used as both carbon source and biofilm support in a fixed-bed reactor to remove nitrate from groundwater. The experimental results showed that the denitrifying bacteria can easily attach to the surface of PBS granules and adapt to use PBS as carbon source. The SEM observation indicated that the fine biofilm can develop on the surface of PBS granules within 15 days. The denitrification rate increased with temperature increase in the range of 10-35°C, the maximum denitrification rate reached 1.00 mg/g.d at 35°C. Continuous experiment results showed that nitrate (50 mg/l) can be removed effectively and nitrite did not accumulate in the effluent.