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The El Niño‐Southern Oscillation (ENSO)‐related interannual variability of the Kuroshio in the East China Sea (ECS) was revisited based on reanalysis outputs during 1993–2018. Unlike the synchronized variations from 2006 to 2018, the period of 1993–2005 showed regional differences in how the ECS‐Kuroshio responded to ENSO events. Specifically, from the upstream region to the midway of the continental slope, the ECS‐Kuroshio exhibited distinct six‐year interannual modulation during 1993–2005. In contrast, downstream Kuroshio variability primarily followed a four‐year cycle, aligning with ENSO variability during the same period. Further analysis suggested that the sea surface height anomaly (SSHA) east of the Kerama Gap, near the midpoint of the Ryukyu Island chain, extended inside the ECS until the southern side of the Tokara Strait along the ECS‐Kuroshio path and was well correlated with the Kuroshio in the Tokara Strait during 1993–2005. The cause of this SSHA signal was attributed to forcing by ENSO‐related wind stress curl changes in the interior region. There was an obvious difference in the ENSO‐related atmospheric circulation before and after 2005. The wind stress curl pattern in the North Pacific during 1993–2005, characterized by a maximum in the Kerama Gap latitude band, shifted northward compared to that during 2006–2018. The relative northward shift of the ENSO‐related wind stress curl, which stimulates the long baroclinic Rossby wave propagating westward and arriving east of the Kerama Gap, affect the interannual variabilities of both the upstream and downstream Kuroshio. Plain Language Summary: The Kuroshio is the western boundary current of the North Pacific Ocean. It plays a significant role in the marine ecosystem and the global heat budget of the East China Sea (ECS). This study revealed that the responses of the Kuroshio in the ECS to the El Niño‐Southern Oscillation (ENSO) show distinctive regional differences from upstream to downstream region during 1993–2005, which is different from the synchronized response during 2006–2018. The sea surface height anomaly (SSHA) east of the Kerama Gap, which is forced by ENSO‐related wind stress curl changes in the North Pacific, could extend inside the ECS until the Tokara Strait along the ECS‐Kuroshio path and is well correlated with the Kuroshio in the Tokara Strait before 2005. Key Points: Upstream and downstream ECS‐Kuroshio exhibited inconsistent (consistent) responses to the ENSO variation before (and after) 2005Variation of the Kuroshio in the Tokara Strait is related to the SSHA east of the Kerama Gap, which may be attributed to the El Niño state before 2005The ENSO‐related wind stress pattern shifted northward during 1993–2005 compared with that during 2006–2018 [ABSTRACT FROM AUTHOR]

In 2015, four typhoons traversed the regions surrounding the Ryukyu Island Chain, resulting in different near‐inertial waves (NIWs), the characteristics of which were investigated through in situ observations around Miyakojima Island and numerical simulations covering the East Asian marginal seas. The spatial distribution of typhoon‐induced near‐inertial motions was significantly correlated with the typhoon tracks and background currents. Typhoons Chan‐hom and Goni traversed the observation transect, resulting in different spatial patterns of NIWs owing to their different tracks. Observations on both the western and eastern sides of the Ryukyu Island Chain failed to capture NIWs after typhoon Chan‐hom, because they were positioned to the left of the typhoon track where near‐inertial motions were enhanced only in the upper 50 m. In contrast, NIWs were negligible on the left side and energetic on the right side of typhoon Goni. Despite being hundreds of kilometers from the observation transect, typhoons Soudelor and Dujuan induced NIWs with higher energy levels than those induced by typhoons Chan‐hom and Goni. The energy propagation of NIWs after typhoons Soudelor and Dujuan was significantly influenced by background currents. The western boundary currents, including the Kuroshio and Ryukyu Currents, create negative relative vorticity on their right, which works like a waveguide for the poleward advection of NIWs. However, the Ryukyu Current can be impeded by westward‐propagating cyclonic eddies from the North Pacific, which further disrupts the waveguide. Plain Language Summary: Near‐inertial waves (NIWs) transfer energy from the surface to the deep ocean and play a crucial role in energy cascades. Based on observations and numerical simulations conducted around Miyakojima Island in the northwestern Pacific, the different spatial patterns of NIWs after four typhoons in 2015 were influenced by variations in typhoon tracks and background currents. The NIWs were negligible and energetic on the left and right sides of the typhoon tracks, respectively. Energetic NIWs can be advected poleward along the northward western boundary currents, including the Kuroshio Current and Ryukyu Current. However, the poleward energy propagation of NIWs can be hindered by cyclonic eddies originating from the North Pacific, which impede the Ryukyu Current and disrupt the favorable conditions for their energy propagation. This study enhances our understanding of the propagation dynamics of wind‐induced NIWs and provides valuable insights into the multiscale interactions in regions with abundant dynamic processes. Key Points: Near‐inertial waves (NIWs) with different features were observed around the Ryukyu Islands following four typhoons in 2015NIWs induced by remote typhoons were observed, but at times, the observations failed to capture those induced by regional typhoonsThe energy propagation of NIWs is influenced by the Kuroshio Current, the Ryukyu Current, and eddies [ABSTRACT FROM AUTHOR]

Sludge retention time(SRT) is a crucial parameter to influence the stability of biological wastewater treatment systems. Especially, the effects of SRT on yeast-wastewater treatment remain unclear. In this study, mixtures of yeast strains were applied to treat oil-containing wastewater in sequencing batch reactors(SBR) and the effects of sludge retention time(SRT as 5, 10, 20, 40 d) on the removal efficiency of pollutants, contents and composition of extracellular polymeric substances(EPS), yeast cells settleability and yeast communities were investigated. The results showed that the recommended SRT was 5-10 d for the yeast-SBR system; Higher SRT led to decrease of COD removal rate and content of EPS; the tightly-bounded EPS was the major one which consisted of polysaccharides. SRT of 5-40 d had no significant effects on the SVI of yeast cells, however, longer SRT (>20 d) resulted in the increase of mycelial cells and a tendency to produce the filamentous bulking. In the continuous operation of SBR, three extraneous yeast strains capable of utilizing or degrading oil were identified in the systems under the short and long SRT. To conclude, shorter SRT was favorable for the system stability in treating oil-containing wastewater by yeasts.

The disposal of urban scattered human feces has become a difficult problem for the management of modern city. In present study, the scattered human feces underwent the collection, scum removal, flocculation and dehydration, finally became the granular fertilizer; the effects of the ratio of fertilizer to soil on the growth of the pakchoi and the quality of soil and leaching water were evaluated, and the feasibility of granular fertilizer manuring the pakchoi was discussed by pot experiments. The results showed that the granular fertilizer significantly enhanced the production of the pakchoi which were not polluted by the intestinal microorganisms under the experiment conditions; meanwhile, at the proper ratio of fertilizer to soil, the concentration of these microorganisms in the leaching water was lower than that in the control check. Chemical analyses of soil revealed that the nutrient content of nitrogen, phosphorus, potassium and organic matters in soil became much richer in all treatments. In addition, the granular fertilizer improved the physical- chemical properties of soil, including raising the level of soil porosity and reducing the volume weight of soil. Application of granular fertilizer won't pollute the soil or leaching water; instead, it can also prevent nitrogen, potassium and intestinal microorganisms from leaching inio ground water at the proper ratio of granular fertilizer to soil.