Step-feeding food waste fermentation liquid as supplementary carbon source for low C/N municipal wastewater treatment: Bench scale performance and response of microbial community.

Municipal wastewater treatment often lacks carbon source, while carbon-rich organics in food waste are deficiently utilized. In this study, the food waste fermentation liquid (FWFL) was step-fed into a bench-scale step-feed three-stage anoxic/aerobic system (SFTS-A/O), to investigate its performance in nutrients removal and the response of microbial community as a supplementary carbon source. The results showed that the total nitrogen (TN) removal rate increased by 21.

Biomanipulation as a strategy for minimizing ecological risks in river supplied with reclaimed water.

Reclaimed water is an effective method for addressing water pollution and shortages. However, its use may contribute to the collapse of receiving water (algal blooms and eutrophication) owing to its unique characteristics. A three-year biomanipulation project was conducted in Beijing to investigate the structural changes, stability, and potential risks to aquatic ecosystems associated with the reuse of reclaimed water in rivers.

Long-period D-fiber grating based robust and efficient bidirectional coupler for whispering gallery mode excitation.

A robust and efficient bidirectional coupler for whispering gallery mode (WGM) excitation based on a long-period grating (LPG) inscribed in D-fiber is theoretically and experimentally demonstrated. The LPG coupling the fundamental core mode to the forward propagating cladding modes according to the phase-matching condition not only enhances the evanescent field of the fiber but also selectively excites the WGM in a wavelength band of interest. Experimental results show that a maximum resonance contrast as high as 10.

Microbial mechanisms of refractory organics degradation in old landfill leachate by a combined process of UASB-A/O-USSB.

A combined process of anaerobic digestion (UASB), shortcut nitrification-denitrification (A/O), and semi-anoxic co-metabolism (operated by an up-flow semi-anoxic sludge bed; USSB) was constructed for the treatment of old landfill leachate (>10 years). The performance and mechanism of refractory organics degradation by the combined process (UASB-A/O-USSB) were investigated. The results showed that the semi-anoxic co-metabolism contributes 57 % of the totally degraded refractory organics.

Control of polarization switching in a VCSEL via resonant feedback from a whispering-gallery-mode cavity.

We report a method for flexibly switching the dominant polarization of a vertical-cavity surface-emitting laser (VCSEL) by introducing polarization-resolved resonant optical feedback from a whispering-gallery-mode (WGM) cavity to the lasing cavity. Switching between the originally dominant mode and a side mode is experimentally demonstrated under different bias currents once one of them is locked to the resonance mode of the WGM cavity. In addition to a controllable polarization state, the reported VCSEL also demonstrates a linewidth as narrow as tens of kilohertz, which is highly desirable for many applications, including high-speed data communication, light detection and ranging (lidar), and absorption spectroscopy.

Simultaneous self-injection locking of two VCSELs to a single whispering-gallery-mode microcavity.

Simultaneous self-injection locking of two vertical-cavity surface-emitting lasers (VCSELs) to a single whispering-gallery-mode (WGM) microcavity is experimentally demonstrated. The linewidths of the two VCSELs are compressed from 3.5 MHz and 5 MHz to 20.