Heterotrophic nitrification and biomineralization potential of Pseudomonas sp. HXF1 for the simultaneous removal of ammonia nitrogen and fluoride from groundwater

Abstract

Pseudomonas sp. HXF1, a strain capable of heterotrophic nitrification, aerobic denitrification (HNAD), and biomineralization was identified and employed for the simultaneous removal of ammonia nitrogen (NH4+-N) and fluoride (F−). It removed 99.2% of NH4+-N without accumulation of nitrous nitrogen (NO2−-N) and nitrate nitrogen (NO3−-N), while removed 87.3% of F−. Response surface methodology (RSM) was used to study the best removal conditions for NH4+-N and F−. The results of nitrogen balance experiments with NH4Cl, NaNO2, and NaNO3 as single nitrogen sources and amplification experiments of denitrification genes proved that the bacterial strains may remove NH4+-N through HNAD. The experimental results of Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer (XRD) indicated that the way of F− removal may be adsorption and co-precipitation. The results demonstrated that the strain HXF1 has great potential in the biological denitrification and F− removal of groundwater.