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The biological early warning system with fish behavior as the detection index is an efficient and rapid early warning technology for the ecological damage caused by water pollutants. However, the attempt to apply the scototaxis (dark preference) behavior of fish to biological early warning is still relatively lacking. In this study, we delved into the dark and light preferences of the rare minnows (Gobiocypris rarus), employing three distinct tank configurations. Additionally, we systematically examined the modulating effects of environmental illumination, nutritional status, and the number of test subjects on this behavior, aiming to establish optimal experimental parameters for its observation. Furthermore, cadmium ions [Cd2+], tricaine methanesulfonate [MS222], and p-chloroaniline were employed as representative heavy metal ions, neuroactive agents, and organic toxicants, respectively, to test the impact of chemicals on scototaxis in gradient concentrations. The results demonstrated that the rare minnow exhibited a clear scototaxis (dark preference), and this behavior was not affected by the nutritional status of the test fish, the illumination, or the number of subjects. While the dark chamber was consistently the preferred location of rare minnows during the chemical exposure tests, the degree of scototaxis by the rare minnow significantly decreased at Cd2+ ≥ 3 mg/L, MS222 ≥ 11 mg/L, and p-chloroaniline ≥ 29 mg/L, suggesting a potential disruption of their innate behavioral patterns by these chemicals. These findings underscore the sensitivity of rare minnows to water pollutants. Therefore, the scototaxis behavior of rare minnows can be a potential and useful behavioral indicator for biological early warning, which can be used for early biological warning of sudden water pollution caused by chemicals such as Cd2+, MS222, and p-chloroaniline. [ABSTRACT FROM AUTHOR]

The use of distributed energy systems (DES) can utilize local resources to achieve flexible and efficient energy production and supply. However, this aspect of pollutant emission reduction has not been sufficiently investigated in current related studies. On this basis, this study establishes a DES system that integrates a ground-source heat pump, a gas turbine, a photovoltaic device and an energy storage device. An Improved Zebra Optimization Algorithm (IZOA) is proposed for optimizing the capacity of DES devices and the energy supply ratio of the ground-source heat pump. Using the economic cost saving rate (ECSR), pollutant emission reduction rate (PERR) and energy saving rate (ESR) as the optimization objectives, the study builds a DES configuration optimization model. By analyzing the arithmetic example of a large hotel building, the study verifies the effectiveness of the IZOA algorithm in solving the DES configuration optimization problem. This study provides useful research ideas in promoting the development of distributed energy systems, environmental protection and energy conservation. [ABSTRACT FROM AUTHOR]

There was a large amount of dredged materials produced stably in the Yangtze waterway each year. How to dispose these dredged materials was a major technical problem in the field of port and waterway engineering. The dredged materials were valuable resource, and the utilization of dredged materials in landscape can be an important direction in the future. To analyze the feasibility of dredging for landscaping, the waterway dredged sediments from middle and lower reaches of the Yangtze River basin, such as Dongting Lake, Chenglingji section, Zhenjiang section, Nantong section and Taihu Lake were collected, and the nutrient characteristics, heavy metal content and pollution degree were analyzed. The results showed that the pH, moisture content, petroleum hydrocarbons, organic matter and available P in Yangtze River waterway dredging sediments were 7.28~7.74, 3.75~28.27%, 14.21~121.84 ppm, 1.88~5.29% and 16.96~65.38 ppm respectively, which were moderate pollution and suitable for plants growth. The content of available N and available K content were 67.12~87.97 ppm and 2.78~20.11 ppm, which were too low to meet the needs of plant growth. Extra sources of nitrogen and potassium should be added into the sediments when reused. Dredged sediments were contaminated by heavy metals Cu, Pb and Zn, the evaluation results showed that their enrichment effect was not obvious, which won’t affect the sediment utilization. Dredged sediments were widely contaminated by Cd (0.05~2.68 mg/kg), and there was a certain enrichment effect, so some Cd hyperaccumulators should be planted to remediate Cd in dredged sediments.

Windbreaks projects are constructed in order to reduce the dusting in port bulk storage yards. The assessment of wind environment and dust suppression effects are important in the planning or preliminary design of such projects. This paper takes a large port bulk storage yard with 853m x 966m area as an example, velocity measurement wind tunnel tests were carried out. The wind velocity reduction ratio and dust suppression rate were used to access the wind environment and the dust suppression effect. The influence of windbreak height was investigated. The comprehensive wind speed reduction rate and dust suppression rate vary with windbreak height nearly linearly. And combined with spraying system, the dust suppression rate can reach beyond 95%, which provides reference and assessment method for relative engineering applications.

With the increasing requirements of environmental protection, a large number of new wet dust suppression technologies are used in the port in recent years, such as watering at the bottom of the Dumper Shed, etc. So the moisture content of coal is more than 10% often appear. Relevant studies show that the amount of dust from coal (conventional moisture content) pile is directly proportional to the high power of wind speed. But studies on high moisture content coal are rare. In this study, Wind tunnel test was carried out to study the dust emission behavior of coal with high moisture content (13.7% and 14.3%). The results show that the relationship between coal dust and wind speed tends to be linear under high moisture content. The study can provide a basis research for the estimation of coal dust emission in port.

Aquatic plant restoration is an important technique for the treatment of eutrophic water bodies. There are significant differences in pollutant removal efficiency among different combinations of aquatic plant species in eutrophic water bodies. Therefore, further research on the selection of suitable combinations of aquatic plant species is of great significance for the restoration of eutrophic water bodies. This study investigated the pollutant removal efficiency and bacterial community structure of three novel combinations of aquatic plants, including Lythraceae, Nymphaea, and Myriophyllum (LNM group), Lythraceae, Nymphaea, and Hydrilla verticillata (LNH group), and Lythraceae, Nymphaea, and Vallisneria (LNV group), as well as a control group (CK group). The components of the CK group were only sediment and culture water without any plants. The results show that on one hand, the LNH group had the highest removal rate of COD (90.29%); the LNV group exhibited the highest removal rates for NH4+-N and TN, with removal rates of 61.20% and 82.94%, respectively; and there was no significant difference in the removal rate of TP among the experimental groups, except for the LNH group, which showed higher initial removal efficiency for TP. On the other hand, plant combinations had different impacts on the top 13 dominant microflora at the phylum level. Proteobacteria and Actinobacteria showed the highest removal efficiency for COD in the LNH group, while Verrucomicrobi, Chloroflex, and Acidobacteria showed higher removal efficiency for NH4+-N and TN in the LNV and LNH groups. In summary, the three different combinations of aquatic plants exhibited distinct pollutant removal characteristics, significantly altered the structure of the microbial community, and provided a theoretical basis for their practical application in the restoration of eutrophic water bodies. [ABSTRACT FROM AUTHOR]