An overlooked effect of hydroxylamine on anammox granular sludge: Promoting granulation and boosting activity.

The exogenous hydroxylamine dosing has been proven to enhance nitrite supply for anammox bacteria. In this study, exogenous hydroxylamine was fed into a sequencing batch reactor to investigate its long-term effect on anammox granular sludge. The results showed that hydroxylamine enhanced the reactor's performance with an increase in total nitrogen removal rate from 0.23 to 0.52 kg N/m3/d and an increase in bacterial activity from 11.65 to 78.24 mg N/g VSS/h. Meanwhile, hydroxylamine promoted granulation by eluting flocs. And higher anammox activity and granulation were supported by extracellular polymeric substances (EPS) characteristics. Moreover, Candidatus Brocadia's abundance increased from 1.10 % to 3.03 %, and its symbiosis with heterotrophic bacteria was intensified. Additionally, molecular docking detailed the mechanism of the hydroxylamine effect. Overall, this study would provide new insights into the hydroxylamine dosing strategy application.

Determination of partial denitrification kinetic model parameters based on batch tests and metagenomic sequencing.

In this study, a model was developed to investigate the partial denitrification(PD) process. The heterotrophic biomass (XH) proportion in the sludge was determined to be 66.4% based on metagenomic sequencing. The kinetic parameters were first calibrated, then validated using the batch tests results. The results showed rapid decreases in the chemical oxygen demand (COD) and nitrate concentrations and gradual increases in the nitrite concentrations in the first four hours, then remained constant from 4 to 8 h. Anoxic reduction factor (ηNO3 and ηNO2) and half saturation constant (KS1 and KS2) were calibrated at 0.097, 0.13, 89.28 mg COD/L, and 102.29 mg COD/L, respectively. Whereas the simulation results demonstrated that the increase in carbon-to-nitrogen (C/N) ratios and the reduction in XH contributed to the increase in the nitrite transformation rate. This model provides potential strategies for optimizing the PD/A process.

Antecedents of Tourists' Environmentally Responsible Behavior: The Perspective of Awe.

The promotion of tourists' environmentally responsible behavior (TERB) plays a central role in destination management for sustainability. Based on the stimulus-organism-response framework, this study proposes an integrated model for behavior management by examining the relationship between stimuli (natural environment and availability of infrastructure) and response factors (satisfaction and TERB) through the organism (the emotion of awe). Survey data from 458 tourists visiting Mount Heng in Hunan Province, Southern China, were used to empirically evaluate the proposed framework. The findings demonstrate that the perception of a destination's natural environment positively impacts tourists' sense of awe and satisfaction; the perception of availability of infrastructure positively and significantly influences awe, satisfaction, and TERB; and awe positively impacts satisfaction and TERB. Moreover, the emotion of awe plays a significant mediating role in this proposed model. The theoretical significance of this study and the implications for tourism destinations are discussed.

Exploration of Leisure Constraints Perception in the Context of a Pandemic: An Empirical Study of the Macau Light Festival.

Individuals' capacity to participate in leisure activities is contingent upon their ability to overcome obstacles. It is worthwhile to investigate how individuals perceive constraints on their leisure activities participation during the COVID-19 pandemic. This study demonstrates that the connotation of leisure constraints during pandemic includes personal health concerns, shock on economic revenue, reduced freedom of travel, and inconvenience associated with epidemic prevention. Reduced travel freedom is the most influential factor on participation intentions, followed by personal health concerns. Significant differences in perceptions of constraints are observed between groups with different characteristics.

Antecedents of Residents' Pro-tourism Behavioral Intention: Place Image, Place Attachment, and Attitude.

Few prior studies have investigated place image from the residents' perspective, how this and residents' place attachment influence attitude to tourism, and consequent reactions. Accordingly, this study aims to develop a model for local residents' pro-tourism behavioral intention and to discover the relationships between constructs. Analysis was based on a sample of 370 residents in Huangshan City, China. Results indicate that residents' attitude to tourism positively affects their pro-tourism behavioral intention. Residents' place image is found to positively relate to place attachment and attitude to tourism, while place attachment is also related to attitude and pro-tourism behavioral intention. In addition, attitude to tourism mediates place image's and place attachment's respective relationships with pro-tourism behavioral intention. Lastly, place image indirectly impacts residents' attitude to tourism and pro-tourism behavioral intention through place attachment. However, the positive relationship between place image and pro-tourism behavioral intention is not supported. Theoretical and practical implications are discussed.