The influence of the novel composite material LiNbO₃@Fe₃O₄ on the denitrification efficiency of bacterium Achromobacter sp. A14

ABSTRACT

The effect of the novel composite material LiNbO₃@Fe₃O₄ on the nitrate removal, and Mn²⁺ oxidation efficiency by autotrophic denitrification strain Achromobacter sp. A14 was investigated in this study. The optimum conditions were tested by using five levels of initial Mn²⁺ concentrations (40, 60, 80, 100 and 120 mg/L), initial pH (5.0, 6.0, 7.0, 8.0 and 9.0) and temperature (20, 25, 30, 35 and 40°C). A maximal nitrate removal ratio of nearly 100% and a maximal Mn²⁺ oxidation ratio of 71.59% were simultaneously achieved at pH 7.0, 80 mg/L Mn²⁺ and 30°C by bacteria A14 with 300 mg/L LiNbO₃@Fe₃O₄ as catalytic material. Biomaterial cycle testing indicated that the denitrification efficiency of bacteria A14 with LiNbO₃@Fe₃O₄ remained steady after 10 batches.

GRAPHICAL ABSTRACT

KEYWORDS:

• Denitrification
• Mn(II) oxidation
• LiNbO₃@Fe₃O₄ biomaterial
• biomaterial cycle

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research work was partly supported by the National Natural Science Foundation of China [grant numbers 51978556, 51678471]; Shaanxi Science Fund for Distinguished Young Scholars [grant number 2019JC-31]; National Key Research and Development Program of China [grant number 2016YFC0400706]; Key Scientific Technological Innovation Team Plan of Shaanxi Province [grant number 2017KCT-19-02]; Key Research and Development Plan in Shaanxi Province of China [grant number 2018ZDXM-SF-029].