The role of microbiome in carbon sequestration and environment security during wastewater treatment

Synthesis, characterization, and application of SrTiO3 via metallic Ag modification in the inactivation of Enterococcus sp. in wastewater

Wastewater reclamation is crucial due to increasing demand and climate change, and disinfection is a key step in the process. However, traditional disinfectants like chlorination produce harmful by-products, prompting the exploration of alternatives such as Advanced Oxidation Processes (AOPs). Peroxymonosulfate (PMS) has emerged as a promising oxidant, especially when combined with heterogeneous catalysts at low concentrations. One example is the development of new nanostructured materials like SrTiO3, enhanced by silver nanoparticle (Ag) doping. This study focuses on the synthesis, characterization, and testing of SrTiO3@Ag for wastewater disinfection, targeting Enterococcus sp., and examining factors such as solar radiation, PMS concentration, and the key species involved in the treatment. In the study, the SrTiO3@Ag material exhibited limited photocatalytic activity under solar radiation at low concentrations, but this was improved by combining it with low concentrations of PMS, leading to the complete elimination of Enterococcus sp. in 45 min. However, adding solar radiation to the SrTiO3@Ag/PMS process had an antagonistic effect, increasing the reaction time. Bacterial elimination likely results from a synergistic mechanism involving the antibacterial properties of Ag nanoparticles, the generation of sulfate radicals from PMS, and electron transfer processes enhanced by light-induced plasmon resonance. Oxidizing radicals and electron transfer are the main contributors to bacterial inactivation.

Wastewater as a resource for carbon capture: A comprehensive overview and perspective

As two important but energy-intense processes, carbon capture and wastewater treatment always attract wide research interests to improve their operational efficiency and technological feasibility. Consequently, utilizing wastewater for carbon capture or integrating carbon capture plants into wastewater treatment facilities has become a promising concept drawing great attention to investigate and demonstrate its feasibility and efficiency. In this study, recent research progress and concept validation studies of utilizing wastewater for carbon capture were briefly reviewed and summarized with the status and main challenges of this concept provided accordingly. Three integration strategies for combining carbon capture with wastewater treatment-utilization of wastewater as the absorbent to capture CO2, biological pathway for simultaneous carbon capture and wastewater treatment, and electrochemical approach to integrate wastewater purification with carbon capture-were primarily reviewed and discussed in this study. Meanwhile, the perspectives of these integrated technology strategies were also discussed providing guidance for future investigations and development of carbon capture with wastewater treatment. Based on our study, the integrated wastewater treatment and carbon capture shows promising prospects in terms of reducing energy consumption and cost of carbon capture and wastewater treatment. However, more relevant studies and demonstrations are still necessary to improve efficiency and reduce possible carbon emissions. As a promising technology contributing to achieving net-zero emission and mitigating global warming, the integration of wastewater treatment and carbon capture will attract more attention in the future.

Modeling Microbial Communities: Perspective and Challenges

Microbial communities are immensely important due to their widespread presence and profound impact on various facets of life. Understanding these complex systems necessitates mathematical modeling, a powerful tool for simulating and predicting microbial community behavior. This review offers a critical analysis of metabolic modeling and highlights key areas that would greatly benefit from broader discussion and collaboration. Moreover, we explore the challenges and opportunities linked to the intricate nature of these communities, spanning data generation, modeling, and validation. We are confident that ongoing advancements in modeling techniques, such as machine learning, coupled with interdisciplinary collaborations, will unlock the full potential of microbial communities across diverse applications.

The performance, mechanism and greenhouse gas emission potential of nitrogen removal technology for low carbon source wastewater

Excessive nitrogen can lead to eutrophication of water bodies. However, the removal of nitrogen from low carbon source wastewater has always been challenging due to the limited availability of carbon sources as electron donors. Biological nitrogen removal technology can be classified into three categories: heterotrophic biological technology (HBT) that utilizes organic matter as electron donors, autotrophic biological technology (ABT) that relies on inorganic electrons as electron donors, and heterotrophic-autotrophic coupling technology (CBT) that combines multiple electron donors. This work reviews the research progress, microbial mechanism, greenhouse gas emission potential, and challenges of the three technologies. In summary, compared to HBT and ABT, CBT shows greater application potential, although pilot-scale implementation is yet to be achieved. The composition of nitrogen removal microorganisms is different, mainly driven by electron donors. ABT and CBT exhibit the lowest potential for greenhouse gas emissions compared to HBT. N2O, CH4, and CO2 emissions can be controlled by optimizing conditions and adding constructed wetlands. Furthermore, these technologies need further improvement to meet increasingly stringent emission standards and address emerging pollutants. Common measures include bioaugmentation in HBT, the development of novel materials to promote mass transfer efficiency of ABT, and the construction of BES-enhanced multi-electron donor systems to achieve pollutant prevention and removal. This work serves as a valuable reference for the development of clean and sustainable low carbon source wastewater treatment technology, as well as for addressing the challenges posed by global warming.

Successional dynamics of microbial communities in response to concentration perturbation in constructed wetland system

Constructed wetlands (CWs) are widely considered as resilient systems able to adapt to environmental perturbations. Little attention has been paid, however, to microbial dynamics when CWs withstand and recover from external shock. To understand the resilience of CWs, this study investigated rhizosphere microbial dynamics when CWs were subjected to influent COD perturbation (200 mg/L-1600 mg/L). Results demonstrated that CWs had strong adaptability to different influent perturbations, characterized by transitions from fluctuating to stable pollutant removal. Microbial analysis showed that rhizosphere microorganisms competed for niches in response to increased COD concentrations, and Trichococcus played key roles in resisting concentration perturbations. Structural equation modeling indicated that rhizosphere community succession and microbial energy metabolism were shaped by pH and DO. These findings provide insights into the mechanism for CW stability maintenance when facing concentration perturbations.