The gravity of the impending threats posed by microplastics (MPs) pollution in the environment cannot be over-emphasized. Several research studies continue to stress how important it is to curb the proliferation of these small plastic particles with different physical and chemical properties, especially in aquatic environments. While several works on how to monitor, detect and remove MPs from the aquatic environment have been published, there is still a lack of explicit regulatory framework for mitigation of MPs globally. A critical review that summarizes recent advances in MPs research and emphasizes the need for regulatory frameworks devoted to MPs is presented in this paper. These frameworks suggested in this paper may be useful for reducing the proliferation of MPs in the environment. Based on all reviewed studies related to MPs research, we discussed the occurrence of MPs by identifying the major types and sources of MPs in water bodies; examined the recent ways of detecting, monitoring, and measuring MPs routinely to minimize projected risks; and proposed recommendations for consensus regulatory actions that will be effective for MPs mitigation.

High gravity technology, as a process intensification technology, has demonstrated the great advantages in the field of gas purification on account of its excellent mass transfer efficiency and energy-efficient, but it is rarely applied in the field of nitrogen oxides (NOx) purification of marine diesel engine exhaust. In this paper, a high-gravity bowl-shaped-disk rotating bed (HBRB) without catalytic was designed for diesel exhaust after-treatment. A diesel oxidation catalyst (DOC) was installed in the front of the HBRB to regenerate more nitrogen dioxide (NO₂) easily reduced by urea. A bench test of a 6-cylinder marine diesel engine with the HBRB was carried out. The effects of the HBRB speeds, urea concentrations, and engine operating conditions on NOx purification efficiency in engine exhaust were experimentally investigated. The experimental result indicates that the maximum NOx removal efficiency of the HBRB can reach 69.1%. The improvement of the NOx removal efficiency is not obvious at the HBRB speed of over 1500 r/min. The pre-oxidation degree of nitric oxide (NO) and urea concentration largely affect the NOx removal efficiency. The HBRB has great potential in marine diesel engine exhaust denitration.

With the deterioration of environmental quality caused by fossil energy use, the research on energy internet and energy misallocation is of critical relevance to achieve low-carbon sustainable development. However, we find that the relevant research that analyzes energy internet and energy misallocation on carbon emissions under the same framework is ignored. For this purpose, the generalized method of moments (GMM), panel threshold model, and spatial analysis (deviation ellipse, hotspot analysis, and geographically and temporally weighted regression (GTWR)) model were applied to investigate the impact of energy internet and energy misallocation on carbon emissions using panel data of 30 provinces in China from 2004 to 2018. The major statistical results include the following: (1) energy misallocation significantly contributes to carbon emissions, while energy internet inhibits carbon emissions. Energy internet can negatively moderate the positive effect of energy misallocation on carbon emissions. (2) The effect of energy misallocation on carbon emissions reveals an inverted “U-shaped” characteristic of first promoting and later inhibiting, but the inhibiting effect is insignificant. Moreover, the marginal effect of energy misallocation on carbon emissions decreases when the energy internet crosses the second thresholds consecutively, while the marginal effect of the energy internet on carbon emissions shows an inverted “N” shape. (3) Compared with the under-allocated regions, the promotion effect of energy misallocation on carbon emissions and the inhibitory effect of energy internet on carbon emissions are stronger in the over-allocated regions, while the energy internet has a more significant negative moderating effect on energy misallocation. (4) The gravity center of China’s carbon emissions gradually shifts to the northwest with time. The longitude of the gravity center (east–west direction) changes greatly, while the latitude of the gravity center (north–south direction) changes less. Besides, the carbon emission hotspot regions centered on Shanxi spread to the neighboring provinces, which form a high-high agglomeration region, and the cold spot region dominated by Qinghai, Guangxi, and Guangdong forms low-low agglomeration characteristics. Finally, the GTWR model shows that the impact of energy internet and energy misallocation on carbon emissions shows significant hierarchical, banded, or block-like characteristics in spatial distribution.

Soiling has a crucial importance regarding its impact mainly for countries that have high soiling levels, dust storms, water scarcity and a great solar energy potential as the case of Morocco. Soiling mitigation is therefore mostly required during spring, due to higher pollen concentration, and summer, due to the lack of heavy precipitation. In this work, systematic measurements of soiling ratio were made in Rabat, city of north-western Morocco, during almost 1 year. Soiling has been evaluated considering the effect of dual-axis tracking that was compared to photovoltaic (PV) on fixed structure. A soiling rate of about 0.22%/day has been found for static PV while only 0.1% was found for PV on tracker. An additional approach of cleaning has been proposed in this paper which aims to use dew water. Using glass samples that were exposed to real environmental conditions, similar to the exposure conditions of PV panels, the soiling ratio was determined. At sunrise time, the subsequent change of the glass sample, from the horizontal position at night into the position of 30° tilt angle during the day, is performed to promote dew flow by the force of gravity acting on the droplets of dew. It has been found that relying only on the change of tilt angle, the average soiling losses were only 3.8% compared with 11.8% for fixed PV. This approach can reduce soiling similarly to solar trackers.

Against the backdrop of current global collaboration on mitigating carbon emissions, how to reduce the energy uses in the Belt and Road Initiative area becomes an urgent and big challenge facing the global community. Using the Eora input-output database, this paper accounts the embodied energy trade between Belt and Road countries in 2015, followed by an investigation of the factors influencing the embodied energy trade through a panel gravity model. Global value chain participation and position are two newly considered factors in analyzing the determinants of embodied energy flow. We find that the main bilateral embodied flow paths are from South Korea to China, China to South Korea, Singapore to China, Ukraine to Russia, and Malaysia to Singapore. Five percent embodied energy flow paths account for 80% of the total bilateral embodied energy flow volume between Belt and Road countries. The gravity model results indicate that gross domestic product (GDP) per capita, population, global value chain participation are the key drivers of bilateral embodied energy trade, while the industrial share of GDP and global value chain position are negatively related to the trade. Energy intensity plays a crucial role in reducing the bilateral embodied energy flow. These results are useful in the policymaking of sustainable development for the Belt and Road Initiative.

The high-quality development of agriculture is closely related to technological innovation, but the evolutionary characteristics of the relationship between agricultural transformation and technological innovation have received little study. This study takes 13 main grain-producing areas of China as the research object. Data collection was from 2004 to 2019. Based on the coupling coordination and responsiveness models, we analyze the spatio-temporal agriculture comprehensive level and the associated response degree of agricultural transformation to technological innovation. The results showed that (1) the comprehensive development of technological innovation showed a growth trend, while the agricultural transformation showed a U-shaped growth trend; (2) the coordinated development of these two systems has been significantly improved, but there are differences in the development speed of each province; (3) the coordinated gravity center moved southward in the spatial pattern, eventually presenting the characteristics of “higher level in the east and lower level in the west, while the higher level in the south and lower level in the north”; (4) the influence of technological innovation on agricultural transformation gradually changed from inhibition to positive promotion. In the end, this paper puts forward suggestions on the high-quality development of agriculture from the relationship of technological innovation and agricultural transformation.

There is an increasing demand for the development of inexpensive and effective approaches for the oil–water separation due to the global concern in oil industries. The present study was conducted to fabricate graphitic carbon nitride/thermoplastic polyurethane (g-C₃N₄/TPU)-coated stainless steel meshes via the dip-coating method to investigate the capability of g-C₃N₄ nanosheets (CN-NS) in oil–water separation. CN-NS was synthesized using the polycondensation process followed by exfoliation with Hummer’s method. We studied the effect of TPU and CN-NS concentration on wettability behavior to obtain an optimized coating solution. CN-NS-coated mesh showed superoleophilic/hydrophobic behavior at CN-NS:TPU ratio of 50:50, and it efficiently passed oil from the emulsified water-in-oil mixture (with 50 wt.% oil) with the efficiency of 99%. The wettability behavior of superhydrophilic/underwater superoleophobic was also obtained at CN-NS:TPU ratio of 80:20, and it was able to separate water from the emulsified water-in-oil mixture with the efficiency of 79% under gravity. Both filters were able to separate free water and oil mixtures with flux and efficiency of 6114 L.m⁻².h⁻¹ and ~ 99.99%, respectively. The mechanism of wettability behavior of the coating is mainly related to the functional groups on the edge of g-C₃N₄-NS, thus increasing the hydrophilic properties of the surface. In addition, the micro-nano hierarchical structure of the surface coating improves its roughness due to the presence of CN-NS, which is effectively embedded into the hydrophilic TPU. More importantly, commercially available TPU chemical and simple fabrication of g-C₃N₄ from an inexpensive precursor make the method reported herein as a significant alternative for large-scale application.

The new coronavirus disease COVID-19 has caused a worldwide pandemic to be declared in a very short period of time. The complexity of the infection lies in asymptomatic carriers that can inadvertently transmit the virus through airborne droplets. This kind of viral disease can infect the human body with tiny particles that carry various bacteria that are generated by the respiratory system of infected patients. In this study, numerical results are proposed that demonstrate the effect of human body temperature and temperature from radiators in a room on the spread of the smallest droplets and particles in an enclosed space. The numerical model proposed in this work takes into account the sedimentation of particles and droplets under the action of gravitational sedimentation and transport in a closed room during the processes of breathing, sneezing or coughing. Various cases were considered, taking into account normal human breathing, coughing or sneezing, as well as three different values of the rate of emission of particles from the human mouth. The heat plume, which affects the concentration of particles in the breathing zone, spreads the particle up to a distance of 4.29 m in the direction of the air flow. It can also be seen from the results obtained that the presence of radiators strongly affects the propagation of particles of various sizes in a closed room. From the obtained results, it should be noted that in order to recommend the optimal social distance, it is necessary to take into account many factors, especially momentum, gravity, human body temperature, as well as the process of natural convection, which greatly affect the propagation of particles in a closed room. The conclusions drawn from the results of this work show that, given the environmental conditions, the social distance of 2 m may not be enough.