Possibilities of joint treatment of spent sugar beet pulp and waste water from a sugar factory

Abstract

The possibility of joint treatment of spent sugar beet pulp and wastewater from a sugar factory was studied in this work. Works focused on processing of spent sugar beet pulp separately or together with other substrates can be found in the literature. In the case of some sugar factories, which have spare capacity in the anaerobic reactor on an anaerobic-aerobic wastewater treatment plant, joint processing of spent sugar beet pulp and wastewater from the sugar factory might be an interesting option. The results of the operation of a pilot plant of an anaerobic reactor with a capacity of 3.5 m3 are discussed. Operation of the pilot plant confirmed the possibility of cofermentation of these materials. The organic loading rate achieved in the anaerobic reactor was higher than 6 kg/(m3·d) (COD), while more than half of the load was provided by spent sugar beet pulp. The addition of sugar beet pulp decreased the concentration of ammonia nitrogen in the anaerobic reactor and it was even necessary to add nitrogen. However, the nitrogen content in sludge water depends on the C:N ratio in the processed sugar beet pulp, therefore this knowledge cannot be generalized. About 1.5 to 2-fold biogas production can be expected from the cofermentation of wastewater with sugar beet pulp in an anaerobic reactor, compared with the biogas production from just wastewater treatment.