Effect of Newly Synthesized Salts and Three Common Micropollutants on the Biochemical Activity of Nitrifiers

Often, different types of contaminants in wastewater are suspected adversely affecting the treatment efficiency a plant (WWTP). Therefore, it is essential to study effects newly synthesized substances on activity activated sludge microorganisms. The aim this was determine effect innovative biosurfactants, i.e., sophorolipids quaternary ammonium salts (SQAS), and three common micropollutants (MPs), diclofenac (DCP), 17α-ethynylestradiol (EE2), 4-nonylenol (4-NP), biochemical all tested more significant nitrite-oxidizing bacteria (NOB) than ammonia-oxidizing (AOB), least respiratory heterotrophic organisms (HET). SQAS inhibited nitrification even at lowest concentration (5 mg L−1) inhibition degree range 37% 78%; highest studied (160 L−1), about 45–96%. In most cases, increased when approached 80–160 L−1. MPs influenced nitrifiers lower extent SQAS. varied from 25% 75%, depending micropollutant its concentration.