Influence of cerium oxide nanoparticles on dairy effluent nitrate and phosphate bioremediation

This study investigated, for the first time, the role of cerium oxide nanoparticles (CeO(2) NPs) on dairy effluent nitrate and phosphate bioremediation using different inoculum sources. Two inoculum sources (wastewater and sludge) were obtained from the dairy wastewater treatment plant unit. A culture was prepared to be tested in the treatment of nitrate and phosphate effluent, and the role of CeO(2) NPs was checked to be completely efficient after 5 days of incubation. The reduction efficiency of nitrate using sludge as inoculum source was improved up to 89.01% and 68.12% for phosphate compared to control. In the case of using wastewater as an inoculum source, the nitrate reduction was improved up to 83.30% and 87.75% for phosphate compared to control. The bacterial richness showed a significant variance (higher richness) between control and other samples. The optimal concentration of CeO(2) NPs for inoculum richness and nitrate and phosphate reduction was (sludge: 1 × 10(−10) ppm) and (wastewater: 1 × 10(−12) ppm). The results revealed that CeO(2) NPs could enhance the microbial growth of different inoculum sources that have a key role in dairy effluent nitrate and phosphate bioremediation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10661-022-10003-0.