Utilizing Infrared Electromagnetic Fields to Increase Anammox Activity and Growth Rates

Abstract

Achieving a rapid start-up of the anammox process is still full of challenges and obstacles due to the slow growth of anammox bacteria. In this study, a new physical energy, infrared electromagnetic fields (EMFs) generated from a widely used traditional Chinese medicine apparatus by accelerating charged particles through thermal excitation, proved to be a “bioactivity enhancer” for the anammox process. Short-term batch tests indicated that the specific anammox activity [26.6 mg of N (g of MLSS)−1 h–1] was increased by 76% after the treatment with infrared EMFs. The long-term effect of the EMFs on anammox was studied in upflow column reactors, and a 36.8% start-up time saving, a 17.7% total nitrogen removal increase, and a 22.5% acceleration of the anammox bacteria growth rate were achieved. The reactor that included EMFs also had better resistance to performance deterioration and shock loading. The high-throughput sequencing results showed that the existence of the EMFs increased the relative abundance of Candidatus Kuenenia and Candidatus Jettenia. Furthermore, the evaluation of the community functions based on the Kyoto Encyclopedia of Genes and Genomes indicated infrared EMFs stimulated anammox bacteria by controlling the metabolism of c-di-GMP. Taken together, infrared EMFs are, therefore, considered to be an efficient “bioactivity enhancer” for promoting the anammox process.

Dosage-Dependent Impacts of Graphene Oxide on the Anammox Process: Performance and Mechanism

“…All functional genes were quantified by a qPCR system (Roche Light Cycler 480, Switzerland) using the manufacturer software. The primers and amplification procedures for each gene in the qPCR experiment are described in Tables S3 and S4 . The next-generation sequencing was used to evaluate the microbial community structure and function .…”

“…The primers and amplification procedures for each gene in the qPCR experiment are described in Tables S3 and S4. 23 The next-generation sequencing was used to evaluate the microbial community structure and function. 24 Amplicons of V4 r e g i o n w e r e s e q u e n c e d u s i n g p r i m e r s 5 1 5 F (GTGCCAGCMGCCGCGGTA) 25 and 806R (GGAC-TACNVGGGTWTCTAAT) 26 by the Illumina Miseq sequencing platform.…”

Rapid Start-Up and Long-Term Stability of Anammox with Magnetic Biochar Addition: Performance Improvement, Microbial Community, and Potential Mechanisms

“…On this basis, it has been found that infrared electromagnetic fields save 36.8% of the start-up time of anammox, improve the growth rate of AnAOB by 22.5%, and increase the abundance of Candidatus kuenenia and C. jettenia. 9 Therefore, the combination of magnetic media with biochar was considered to prepare magnetic biochar for the start-up of anammox. Previous research has provided preliminary evidence that magnetic biochar had higher capacitance and conductivity than pyrolytic biochar, providing more electron-transfer sites and less resistance to electron transfer, which could facilitate ETC.…”

“…On this basis, it has been found that infrared electromagnetic fields save 36.8% of the start-up time of anammox, improve the growth rate of AnAOB by 22.5%, and increase the abundance of Candidatus kuenenia and C. jettenia . Therefore, the combination of magnetic media with biochar was considered to prepare magnetic biochar for the start-up of anammox.…”