Contribution of nitrous oxide to the carbon footprint of full-scale wastewater treatment plants and mitigation strategies- a critical review.

Nitrous oxide (NO), a potent greenhouse gas, significantly contributes to the carbon footprint of wastewater treatment plants (WWTPs) and contributes significantly to global climate change and to the deterioration of the natural environment. Our understanding of NO generation mechanisms has significantly improved in the last decade, but the development of effective NO emission mitigation strategies has lagged owing to the complexity of parameter regulation, substandard monitoring activities, and inadequate policy criteria. Based on critically screened published studies on NO control in full-scale WWTPs, this review elucidates NO generation pathway identifications and emission mechanisms and summarizes the impact of NO on the total carbon footprint of WWTPs.

[Characteristics, Ozone Formation Potential, and Source Apportionment of VOCs During the COVID-19 Epidemic in Xiong'an].

Many restrictive measures were implemented in China from January-February 2020 to control the rapid spread of COVID-19. Many studies reported that the COVID-19 lockdown impacted PM, SO, volatile organic compounds (VOCs), etc. VOCs play important roles in the production of ozone and PM.

Pilot-scale demonstration of one-stage partial nitritation/anammox process to treat wastewater from a coal to ethylene glycol (CtEG) plant.

One-stage partial nitritation/anammox (PN/A) process has been recognized as a sustainable technology to treat various domestic and industrial wastewater, due to its low aeration consumption and chemical dosage. However, there is no study to investigate the feasibility of PN/A to treat coal to ethylene glycol (CtEG) wastewater yet, which contains very complex and toxic compounds including ammonium, ethylene glycol, methanol and phenolic. This study for the first time achieved stable one-stage PN/A process in a pilot-scale integrated fixed-film activated sludge (IFAS) reactor treating real wastewater produced from a CtEG plant.

Evaluation of the joint effects of Cu, Zn and Mn on completely autotrophic nitrogen-removal over nitrite (CANON) process.

The completely autotrophic nitrogen-removal over nitrite (CANON) process has merits in energy saving and consumption reducing, thus being considered as an attractive alternative over the common denitrification technology. In this study, the effects of three common heavy metals (Cu, Zn and Mn) in wastewater to the CANON process were evaluated comprehensively. A central composite design with response surface methodology was utilized to investigate the joint effect of these three metal ions on the nitrogen removal performance of CANON process.

Performance and microbial community dynamics relationship within a step-feed anoxic/oxic/anoxic/oxic process (SF-A/O/A/O) for coking wastewater treatment.

A step-feed anoxic/oxic/anoxic/oxic (SF-A/O/A/O) was developed and successfully applied to full-scale coking wastewater treatment. The performance and microbial community were evaluated and systematically compared with the anoxic/oxic/oxic (A/O/O) process. SF-A/OA/O process exhibited efficient removal of COD, NH-N, TN, phenols, and cyanide with corresponding average effluent concentrations of 317.

Nitrogen Removal Efficiency for Pharmaceutical Wastewater with a Single-Stage Anaerobic Ammonium Oxidation Process.

A single-stage anaerobic ammonium oxidation (ANAMMOX) process with an integrated biofilm-activated sludge system was carried out in a laboratory-scale flow-through reactor (volume = 57.6 L) to treat pharmaceutical wastewater containing chlortetracycline. Partial nitrification was successfully achieved after 48 days of treatment with a nitrite accumulation of 70%.

Mitigation of antibiotic resistance in a pilot-scale system treating wastewater from high-speed railway trains.

Wastewater from high-speed railway trains represents a mobile reservoir of microorganisms with antibiotic resistance. It harbors abundant and diverse antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). This study investigated the removal of ARB and ARGs in a pilot-scale reactor, which consisted of an anaerobic/anoxic/oxic process, anaerobic/anoxic/aerobic process, and ozone-based disinfection to treat 1 m/day wastewater from an electric multiple unit high-speed train.