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Nitrogen pollution is a worldwide problem and has been extensively treated by canonical denitrification (CDN) process. However, the CDN process generates several issues such as intensive greenhouse gas (GHG) emissions. In the past years, a novel biological nitrogen removal (BNR) process of oxygenic denitrification (O2DN) has been proposed as a promising alternative to the CDN process. The classic denitrification four steps are simplified to three steps by O2DN bacteria without producing and releasing the intermediate nitrous oxide (N 2 O), a potent GHG. In this article, we summarized the findings in previous literatures as well as our results, including involved microorganisms and metabolic mechanisms, functional genes and microbial detection, kinetics and influencing factors and their potential applications in wastewater treatment. Based on our knowledge and experience, the benefits and limitations of the current O2DN process were analyzed. Since O2DN is a new field in wastewater treatment, more research and application is required, especially the development of integrated processes and the quantitative assessment of the contribution of O2DN process in natural habitats and engineered systems. [ABSTRACT FROM AUTHOR]

Background: Few studies have explored PM 10 's connection with specific respiratory and cardiovascular emergency department admissions (EDAs). This study aimed to examine the overall effects of PM 10 on EDAs for cardiovascular and respiratory diseases, including specifically, cerebrovascular events (CVE), ischemic heart disease (IHD), arrhythmia, heart failure (HF), upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), chronic obstructive pulmonary disease (COPD) and asthma., Methods: We collected daily data for EDAs from the 10 largest hospitals in Beijing, between January 2013 and December 2013 as well as daily measurements of PM 10 from 17 stations in Beijing. The generalized-additive model was utilized to evaluate the associations between daily PM 10 and cardio-pulmonary disease admissions. Differences in gender, age, and season groups were also examined by models. Relative risks (RR) with 95% confidence interval (CI) were calculated based on subtype, age, gender and seasonal groups. In all, there were approximately 56,212 cardiovascular and 92,464 respiratory emergency admissions presented in this study., Results: The largest estimate effects in EDAs of total cardiovascular disease, CVE, IHD, total respiratory diseases, URTI, LRTI and COPD were found for PM 10 at day 4 (accumulative) moving average, were 0.29% (95% CI:0.12%, 0.46%), 0.36% (95% CI:0.11%, 0.61%), 0.68% (95% CI:0.25%, 1.10%), 0.34% (95% CI:0.22%, 0.47%), 0.35% (95% CI:0.18%, 0.51%), 0.34% (95% CI:0.14%, 0.55%), 2.75% (95% CI:1.38%, 4.12%) respectively. In two-pollutant models and full-pollutant model modified confounding factors, the positive correlation remained unchanged. The elderly (age ≥ 65 years) and male subjects were more susceptible to specific respiratory diseases. PM 10 's impact on EDAs for HF was found higher during the hot season however, EDAs for COPD peaked during the cold season., Conclusion: The study markedly informed that PM 10 pollution was strongly associated with EDAs for cardio-pulmonary diseases. The effects of PM 10 pollution on COPD and heart failure EDAs were clearly determined by seasonal-temperatures., (Copyright © 2018. Published by Elsevier B.V.)