Two-step pilot-scale anaerobic treatment of sugar-beet pulp

Sugar beet pulp is a very suitable material for anaerobic biodegradation. This work investigates anaerobic treatment of sugar beet pulp in a pilot plant. The pilot plant consisted of an acidogenic reactor (volume 5.3 m(3)) and an methanogenic reactor (volume 3.5 m(3)). It was found that designed technology was convenient for both, high degradation of beet pulp dry matter and sufficient specific biogas production. Recommended organic loading rate for the acidogenic reactor was 20 kg, COD m(-3) d(-1), hydraulic retention time 4 days, and maximum content of acidified pulp (dry matter) in this reactor - 6-7%. During the operation period, the organic loading of the methanogenic reactor achieved was 21 kg COD m(-3) d(-1). Hydraulic retention time in this reactor varied from 27 days (at the loading 3 kg m(-1) d(-1)) to 3.9 days (at the loading 21 kg m(-1) d(-1)). An average value of specific biogas production was 0.391 m(3) per kg of dried beet pulp added. The average efficiency of dried pulp matter degradation was 91.5%.