Studies on Rapid Initiation of Anammox Process for Starch Industry Effluent Treatment

Abstract

Nitrogenous waste removal is a critical step in food processing industries, which is usually carried out by nitrification–denitrification pathway. Anaerobic ammonium oxidation (Anammox) is a new pathway which reduces time and cost both by utilizing nitrite as an electron donor to oxidize ammonia by specific bacteria from planctomycetes group. Several lab scales, as well as industrial reactor start-up, was carried out based on Anammox using seed from the same pilot reactor. But the technology is still unpopular, due to prominent start-up information in large scale. This work was collaboratively carried out to identify the possibility of Anammox reactor start-up, to find out seeding bacteria and possible reason of operational failure of Anammox reactor treating starch industry effluent. A wide range of natural source was screened for the presence of Anammox using synthetic media, the sludge from aeration tank of starch plant, and peat bog sample from forest land was found to be active and reducing 61.90% ammoniacal nitrogen and 99.02% nitrite anoxically. This sludge was further enriched and transferred to 5 L reactor to check the removal efficiency of actual starch industry effluent. After 150 days of operation with a food to microorganism ratio of 0.75–0.92, a removal of 89% ammoniacal nitrogen load and more than 99% nitrite load were observed. The visible cluster of red Anammox biomass was also observed insignificant number from 90 days of reactor operation. Phylogenetic characterization studies of sludge also reveal the presence of Candidatus Kuenenia stuttgartiensis and C. Brocardia fulgida in reactor and in peat bog sludge from forest land and aeration tank sample from Sukhjit Starch Industries effluent treatment plant.