Influence of temperature on performance and mechanism of advanced synergistic nitrogen removal in lab-scale denitrifying filter with biogenic manganese oxides

• Published in: Chemosphere (Oxford) 2024-07, Vol.359, p.142269-142269, Article 142269
• Main Authors: Cheng, Qingfeng, Tian, Hui, Zuo, Yanting, Nengzi, Lichao, Du, Erdeng, Peng, Mingguo, Cheng, Xiuwen
• Format: Article
• Language: English
• Subjects: Advanced synergetic nitrogen removal; anaerobic ammonium oxidation; carbon; chemical oxygen demand; denitrification; Denitrifying filter; manganese; microbial activity; Microbial community structure; municipal wastewater; nitrogen; oxidation; Secondary effluent; Temperature; total nitrogen; water temperature
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.142269

Temperature is a significant operational parameter of denitrifying filter (DF), which affects the microbial activity and the pollutants removal efficiency. This study investigated the influence of temperature on performance of advanced synergistic nitrogen removal (ASNR) of partial-denitrification anammox (PDA) and denitrification, consuming the hydrolytic and oxidation products of refractory organics in the actual secondary effluent (SE) as carbon source. When the test water temperature (TWT) was around 25, 20, 15 and 10 °C, the filtered effluent total nitrogen (TN) was 1.47, 1.70, 2.79 and 5.52 mg/L with the removal rate of 93.38%, 92.25%, 87.33% and 74.87%, and the effluent CODcr was 8.12, 8.45, 10.86 and 12.29 mg/L with the removal rate of 72.41%, 66.17%, 57.35% and 51.87%, respectively. The contribution rate of PDA to TN removal was 60.44%∼66.48%, and 0.77–0.96 mg chemical oxygen demand (CODcr) was actually consumed to remove 1 mg TN. The identified functional bacteria, such as anammox bacteria, manganese oxidizing bacteria (MnOB), hydrolytic bacteria and denitrifying bacteria, demonstrated that TN was removed by the ASNR, and the variation of the functional bacteria along the DF layer revealed the mechanism of the TWT affecting the efficiency of the ASNR. This technique presented a strong adaptability to the variation of the TWT, therefore, it has broad application prospect and superlative application value in advanced nitrogen removal of municipal wastewater. [Display omitted] •CODcr, NO3−-N, NH4+-N and TN were effectively removed by ASNR.•The removal rate of TN still reached to 74.87% at around 10 °C.•The denitrifying bacteria and anammox bacteria activity was affected by the TWT.•The actual CODcr consumption for removing 1 mg TN was significantly reduced.•This technique has superlative application value and broad application prospect.