不同盐度下异养氨同化对高盐废水脱氮效能的影响及其机理研究

Study on the Effect and Mechanism of Heterotrophic Ammonium Assimilation on Nitrogen Removal Efficiency in High-Salinity Wastewater under Different Salinities

摘要: 高盐废水生物脱氮是水处理领域的难点，传统硝化–反硝化工艺受盐度抑制严重。研究构建了一种基于异养氨同化(HAA)的序批式生物膜反应器(SBBR)，旨在实现高盐废水的绿色高效脱氮。通过梯度盐度驯化，系统考察了盐度(3%~7%)对脱氮性能的影响，并结合16S rRNA高通量测序分析了微生物群落结构演变。结果表明，当盐度 ≤ 5%时，系统对总氮(TN)和氨氮($N{H}_4^{+}-N$ )的去除率分别稳定在86.3%~89.6%和80%以上，COD去除率维持在89.5%~90.0%之间；盐度升至7%时，TN去除率仍达86.4%。周期实验显示，在盐度3%条件下，亚硝酸盐氮在2 h内完全消失，硝酸盐氮未出现显著积累。微生物群落分析表明，Halomonas属为绝对优势菌属，在盐度3%和7%条件下的相对丰度分别达65.7%和75.6%，系统中未检测到典型自养硝化菌。文章为高盐废水的低碳处理和氮资源回收提供了新的技术思路，在盐度耐受性、温室气体减排和工艺简化方面展现出显著优势。

Abstract: Biological nitrogen removal from high-salinity wastewater remains a significant challenge in the field of water treatment, as conventional nitrification-denitrification processes are severely inhibited by salt stress. In this study, a sequencing batch biofilm reactor (SBBR) based on heterotrophic ammonia assimilation (HAA) was developed to achieve efficient and green nitrogen removal from high-salinity wastewater. Through gradient salinity acclimation, the effects of salinity (ranging from 3% to 7%) on nitrogen removal performance were systematically investigated, and the evolution of the microbial community structure was analyzed using 16S rRNA high-throughput sequencing. The results showed that at salinities ≤ 5%, the removal rates of total nitrogen (TN) and ammonia nitrogen ($N{H}_4^{+}-N$ ) stabilized at 86.3%~89.6% and above 80%, respectively, while the COD removal rate remained between 89.5% and 90.0%. Even when salinity increased to 7%, the TN removal rate still reached 86.4%. Batch experiments under 3% salinity demonstrated that nitrite nitrogen was completely removed within 2 hours, and no significant accumulation of nitrate nitrogen was observed. Microbial community analysis revealed that Halomonas was the dominant genus, with relative abundances of 65.7% and 75.6% at salinities of 3% and 7%, respectively, while typical autotrophic nitrifying bacteria were not detected in the system. This study provides a novel technological approach for the low-carbon treatment of high-salinity wastewater and nitrogen resource recovery, demonstrating significant advantages in salt tolerance, greenhouse gas emission reduction, and process simplification.