Article,
Low-voltage stimulated denitrification performance of high-salinity wastewater using halotolerant microorganisms
Affiliations
- [1] Zhejiang Gongshang University [NORA names: China; Asia, East];
- [2] Zhejiang Agriculture and Forestry University [NORA names: China; Asia, East];
- [3] Ghent University Global Campus [NORA names: South Korea; Asia, East; OECD];
- [4] Shanghai Jiao Tong University [NORA names: China; Asia, East];
- [5] Technical University of Denmark [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD]
Abstract
Nitrate is a common contaminant in high-salinity wastewater, which has adverse effects on both the environment and human health. However, conventional biological treatment exhibits poor denitrification performance due to the high-salinity shock. In this study, an innovative approach using an electrostimulating microbial reactor (EMR) was explored to address this challenge. With a low-voltage input of 1.2 V, the EMR reached nitrate removal kinetic parameter (k) of 0.0166–0.0808 h under high-salinities (1.5 %-6.5 %), which was higher than that of the microbial reactor (MR) (0.0125–0.0478 h). The mechanisms analysis revealed that low-voltage significantly enhanced microbial salt-in strategy and promoted the secretion of extracellular polymeric substances. Halotolerant denitrification microorganisms (Pseudomonas and Nitratireductor) were also enriched in EMR. Moreover, the EMR achieved a NO-N removal efficiency of 73.64 % in treating high-salinity wastewater (salinity 4.69 %) over 18-cycles, whereas the MR only reached 54.67 %. In summary, this study offers an innovative solution for denitrification of high-salinity wastewater.