RESUMEN
Solar desalination is one of the most promising technologies to address global freshwater shortages. However, traditional evaporators encounter the bottleneck of reduced evaporation rate or even failure due to salt accumulation in high-salinity water. Inspired by ancient waterwheels, we have developed an adaptively rotating evaporator that enables long-term and efficient solar desalination in brines of any concentration. The evaporator is a sulphide-loaded drum-type biochar. Our experiments and numerical simulations show that this evaporator, thanks to its low density and unique hydrophilic property, rotates periodically under the center-of-gravity shift generated by salt accumulation, achieving self-removal of salt. This allows it to maintain a high evaporation rate of 2.80 kg m-2 h-1 within 24 h even in saturated brine (26.47%), which was not achieved previously. This proof-of-concept work therefore demonstrates a concentration- and time-independent, self-rotation-induced solar evaporator.
RESUMEN
From the viewpoint of BDS bridge displacement monitoring, which is easily affected by background noise and the calculation of a fixed threshold value in the wavelet filtering algorithm, which is often related to the data length. In this paper, a data processing method of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN), combined with adaptive threshold wavelet de-noising is proposed. The adaptive threshold wavelet filtering method composed of the mean and variance of wavelet coefficients of each layer is used to de-noise the BDS displacement monitoring data. CEEMDAN was used to decompose the displacement response data of the bridge to obtain the intrinsic mode function (IMF). Correlation coefficients were used to distinguish the noisy component from the effective component, and the adaptive threshold wavelet de-noising occurred on the noisy component. Finally, all IMF were restructured. The simulation experiment and the BDS displacement monitoring data of Nanmao Bridge were verified. The results demonstrated that the proposed method could effectively suppress random noise and multipath noise, and effectively obtain the real response of bridge displacement.
RESUMEN
Integrating solar evaporation-driven desalination and electricity production has emerged as a promising approach to alleviate energy crisis and freshwater scarcity. However, there remain huge challenges to achieve high water productivity and steady power generation efficiency. Herein, a compact evaporation-induced water-electricity co-generation device was proposed using a bio-waste squid ink sphere-based cellulose fabric as an evaporator and a silicon nanowires array-based evaporation-driven moist-electric generator. The efficient localized solar thermal heating of the photothermal component leads to significant enhancement in freshwater yield, and the latent heat of vapor condensation is recycled to promote the electricity generation. More notably, the device is capable of harvesting wind energy toward all-weather water and power generation. The fabricated device demonstrated a high evaporation rate of 2.17 kg m-2 h-1 with a collection rate of 66.7% and a maximum output voltage of 1.48 V under one sun illumination with a wind speed of 4 m s-1. The outdoor experiments display a maximum water evaporation rate of 1.84 kg m-2 h-1 with a maximum output voltage of 1.35 V even on cloudy days. Such superior performance of a comprehensive device has great potential for sustainable and practical application in freshwater and electricity generation.
RESUMEN
Delivering sufficient water to the evaporation surface/interface is one of the most widely adopted strategies to overcome salt accumulation in solar-driven interfacial desalination. However, water transport and heat conduction loss are positively correlated, resulting in the trade-off between thermal localization and salt resistance. Herein, a 3D hydrogel evaporator with vertical radiant vessels is prepared to surmount the long-standing trade-off, thereby achieving high-rate and stable solar desalination of high-salinity. Experiments and numerical simulations reveal that the unique hierarchical structure, which consists of a large vertical vessel channel, radiant vessels, and porous vessel walls, facilitates strong self-salt-discharge and low longitudinal thermal conductivity. With the structure employed, a groundbreaking comprehensive performance, under one sun illumination, of evaporation rate as high as 3.53 kg m-2 h-1 , salinity of 20 wt%, and a continuous 8 h evaporation is achieved, which thought to be the best reported result from a salt-free system. This work showcases the preparation method of a novel hierarchical microstructure, and also provides pivotal insights into the design of next-generation solar evaporators of high-efficiency and salt tolerance.
RESUMEN
Solar steam generation and photocatalytic degradation have been regarded as the most promising techniques to address clean water scarcity issues. Although enormous efforts have been devoted to exploring high-efficiency clean water generation, many challenges still remain in terms of single decontamination function, relatively low efficiency, and inability to practical application. Herein, we first report the bioinspired fabrication of black titania (BT) nanocomposites with moth-eye-like nanostructures on carbon cloth for solar-driven clean water generation through solar steam generation and photocatalytic degradation. The moth-eye-like BT nanoarrays can largely prolong the effective propagation path of absorbing light and enhance the scattering of light, thereby exhibiting outstanding light absorption of 96% in the full spectrum. Such hierarchical-nanostructured BT nanocomposites not only impressively achieve solar steam efficiency of 94% under a simulated light of 1 kW m-2 but also show the prominent performance of desalination and steam generation in real life condition. In addition, 96% of rhodamine B is degraded using BT nanocomposites as a photocatalyst in 100 min. The moth-eye-like bioinspired designing concept and bifunctional applications in this study may open up a new strategy for maximizing solar energy utilization and clean water generation.
