Studies on the Biological Treatment of Wastewater from Starch Industry for Pollution Control (PDF)

Doctoral Thesis / Dissertation from the year 2020 in the subject Biology - Miscellaneous, grade: A, National Institute Of Technology Durgapur (National Institute of Technology Durgapur), course: PhD in Biotechnology, language: English, abstract: The present research work was undertaken for the biological treatment of starch industry wastewater for pollution control. Starch industry effluent generates a large volume of wastewater with strong acidity and enormous carbon and nitrogen pollutants. In the present study, the development of low pH methanogens and anammox microorganisms were given special attention. Low pH methanogenic reactor and anammox reactor were fabricated for the biological treatment of corn starch industry effluent. In the first part of the work, low pH tolerant methanogens were isolated from peat bog of leaf debris.

It showed the presence of Gram-negative, non-spore forming, and cocci with creamish black colour colonies. The leaf debris inoculum was taken for optimum COD removal under anaerobic conditions.

Identification and isolation of anammox group of bacteria were performed using enrichment and 16S rRNA amplicon analysis. The objective of the study was to remove ammonia under the anaerobic condition from starch industry effluent. The media optimization using carbon and nitrogen source was undertaken which is required for anammox enrichment. The physical growth factors like temperature and pH were optimized. The optimized temperature and pH were 39 0C and 7.2 respectively. Some restrictive growth factors like salinity and antibiotic concentration were also studied which were found insignificant in our study.

Finally, the overall process was scaled up in the laboratory reactor. The reactor study revealed that in the anaerobic reactor 1.16 kg COD/kg VSS/d was removed producing 42-46% methane as output gas. The anammox reactor was able to reduce 82% nitrogen load from starch industry effluent at the rate of 1.5 kg/m3/d after 568 days of initiation.