Regulation and microbial response mechanism of nitric oxide to copper-containing swine wastewater treated by Pistia stratiotes

• Published in: Environmental pollution (1987) Vol. 359; p. 124560
• Main Authors: Hou, Tianbao, Liu, Jiahua, Yao, Yanpo, Chen, Kecheng, Mao, Chunchun, Zhang, Jingwen, Li, Zhucheng, Zhang, Keqiang, Yang, Peng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.10.2024
• Subjects: Copper; Microorganisms; Phytoremediation; Pistia stratiotes; NO; Microorganisms; Pistia stratiotes; Copper; Phytoremediation
• ISSN: 0269-7491; 1873-6424; 1873-6424
• DOI: 10.1016/j.envpol.2024.124560

As a signaling molecule, Nitric oxide (NO) has been widely used in abiotic stress mitigation studies.Pistia stratiotes showed a good synergistic removal effect on heavy metals, nitrogen and phosphorus, but the high concentration of copper(Cu) in swine wastewater inhibited the comprehensive removal ability of Pistia stratiotes. At present, it is not clear how the addition of NO regulates the stress resistance mechanism of Pistia stratiotes to copper in swine wastewater, and the microbial response mechanism accompanying this process is not yet clear. Therefore, in the concentration range of 0.31∼4 mg·L−1Cu2+ and NO concentration of 0,0.05 and 0.1 mg L−1, the removal effect of Pistia stratiotes on copper from swine wastewater was studied. The results showed as follows: The treatment of non-available copper in groups M and H increased by 10.67% and 22.31%, respectively, compared with that in group L. The critical point of inhibiting effect of NO on growth rate was 2.03 mg·L−1Cu. By measuring three-dimensional fluorescence spectrum, combined with parallel factor analysis and principal component analysis, it was confirmed that exogenous addition of NO affected the humification degree of dissolved organic matter(DOM) and promoted the chelation of organic matter with copper. With the increase of Cu concentration, the Reyranella and Prosthecobacter with certain copper resistance gradually gained advantages. Redundancy analysis(RDA) showed that Emiticicia had a strong correlation with the removal rates of ammonia nitrogen, total phosphorus and copper in swine wastewater, while hgcI_clade had a strong correlation with the removal rates of total nitrogen. In conclusion, controlling the dosage of NO can effectively improve the tolerance and removal effect of Pistia stratiotes on copper in swine wastewater, which is of great significance for promoting the treatment and resource transformation of swine wastewater. [Display omitted] •The copper ionic concentration in water of NO treatment is lower.•Inappropriate concentration of NO affected the adsorption of Cu by water lettuce.•NO affected the degree of DOM humification to alleviate copper stress.