Nitrate removal performances of a new aerobic denitrifier, Acinetobacter haemolyticus ZYL, isolated from domestic wastew
- PDF / 2,849,038 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 69 Downloads / 196 Views
RESEARCH PAPER
Nitrate removal performances of a new aerobic denitrifier, Acinetobacter haemolyticus ZYL, isolated from domestic wastewater Ying Wang1 · Yu‑Lan Zou1 · Hu Chen2 · Yong‑Kang Lv1,2 Received: 1 July 2020 / Accepted: 14 September 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract A new aerobic denitrifying bacterium ZYL was isolated from domestic wastewater sludge and identified as Acinetobacter haemolyticus (similarity 99%) by the 16S rDNA sequencing analysis. The strain could use nitrate, nitrite and ammonium as the sole N-source for growth with a final product of N2, demonstrating its good abilities for aerobic denitrification and heterotrophic nitrification. Single-factor experiment results showed that the effective removal of nitrate by strain ZYL occurred with carbon source sodium succinate, C/N 16–24, pH 5–9, temperature 20–40 °C, DO ≥ 4.84 mg/L. Ammonium was preferentially used by strain ZYL with nitrate and ammonium as the mixed nitrogen sources. According to nitrogen utilization, nitrogen balance analysis, enzyme assay and denitrifying gene amplification, nitrate was assimilated directly by the isolate for cell synthesis and also converted into N 2 through aerobic denitrification. All these make strain ZYL an ideal choice for treating nitrogen-containing wastewater. Keywords Acinetobacter haemolyticus · Aerobic denitrification · Denitrifying pathway
Introduction Due to the over-consumption of nitrogen fertilizers and the intensive development of industry activities, nitrogen pollution that can cause eutrophication of water bodies and affect human health has become more and more serious [1, 2]. Thus, the nitrogen removal from wastewater has become one of the most important problems in water pollution control. Biological methods are widely used for nitrogen removal due to their merits such as no secondary pollution, high-efficiency and cost benefit [3]. Traditionally, nitrogen removal process involves aerobic nitrification by autotrophic nitrifiers and anoxic denitrification by anoxic denitrifiers [4]. Obviously, the key to high-efficiency nitrogen removal is the * Ying Wang [email protected] * Hu Chen [email protected] 1
Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
Innovation Institute of Environmental Industry, College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China
2
successive exposure of wastewater under aerobic and anoxic conditions, but this is difficult to assure a strict anoxic environment by completely removing dissolved oxygen (DO) from wastewater. Therefore, the denitrifying performance of most denitrifiers is inhibited by the insufficient anoxic condition, leading to the decrease in removal efficiency of nitrogen. Aerobic denitrification is first reported by isolated Paracoccus denitrificans, which is able to reduce nitrate or nitrite to N2 under aerobic culture condition [5
Data Loading...
