Keywords: bioaugmentation, industrial wastewater, nitrification, soil nitrifying enrichment cultures, Nitrosomonas, wastewater treatment, nitrogen removal, desert soils, toxicity, salt-tolerant nitrifiers, biofilm
Enhanced nitrification in industrial wastewater after augmentation by soil nitrifying enrichments
Nitrification (the oxidation of ammonia to nitrate) is a key process in the removal of nitrogen from wastewater, a crucial step in wastewater purification before reuse or discharge to the environment. In this research, we examined a new strategy for ensuring significant nitrification in toxic industrial wastewater by using stress-tolerant nitrifying enrichment cultures harvested from desert soils. Plastic beads covered with biofilm of high salt-tolerant nitrifiers were used in bioaugmentation experiments of wastewater from different sources. The results showed that bead-attached nitrifiers were more active than suspended ones, and significant full nitrification was achieved in industrial wastewater that has no nitrifying activity at all. Our results indicate that using sludge from treatment plants or isolated strains is not always the right practice to enhance nitrification in wastewater. Specific environments can be the source of nitrifying consortia suitable for the treatment of wastewater with distinct properties.