Morphology and motor behavior of endemic fishes in the upper reaches of the Yangtze River basin.

Dam construction alters the hydrodynamic conditions, consequently impacting the swimming behavior of fish. To explore the effect of flow hydrodynamics on fish swimming behavior, five endemic fish species in the upper Yangtze River basin were selected. Through high-speed video visualization and computer analysis, these species' swimming patterns under different flow velocities (0.1-1.2 m/s) were investigated. The kinematic and morphological characteristics of the fish were presented. The principal component analysis was used to analyse the main factors influencing the swimming ability of fish and to determine the correlation coefficients among fish behavior indicators. Fish exhibited three different swimming patterns under different flow velocities. Low velocity (0.1-0.3 m/s) corresponds to free motion, middle velocity (0.4-0.7 m/s) corresponds to cruising motion, and high velocity corresponds to stress motion (0.8-1.2 m/s). The fish kinematic index curves were obtained, and four of five fish species showed two extreme points, which means the optimal and adverse swimming strategies can be determined. With the increase in flow velocity, the tail-beat frequency showed an increasing trend, whereas the tail-beat angle and amplitude showed a decreasing trend. Morphological and kinematic parameters were the two main indexes that affect the swimming ability of fish, which accounts for 41.9% and 26.9%, respectively.

Temperature and pH dual response flexible silica aerogel with switchable wettability for selective oil/water separation.

Silica aerogels are attractive oil-absorbing agents due to their low density, high porosity. However, how to discharge the oil which adsorbed by silica aerogels is a difficult issue. To address this challenge, new separation strategies with high efficiency are needed. In this study, we prepared the temperature and pH dual response flexible silica aerogel have temperature response and pH response effect, which can change its wettability by adjusting temperature or pH. On the one hand, the temperature and pH responsive flexible silica aerogel can be used to adsorb water at the temperature below 34.73 °C or pH > 7. On the other hand, it can adsorb oil at a temperature above 34.73 °C or pH < 7. The automatic desorption of oil can be achieved without consuming additional energy and damaging the pore structure. Therefore, the sample could continuously adsorb and filtrate efficiently and realize the recovery of oil and adsorption materials.

Evolution and speciation transformation of chlorine during automobile shredder residue pyrolysis.

Disposal of automobile shredder residue (ASR) via pyrolysis enables the recovery of valuable products; however, the production of hazardous pollutants and low-value products is inevitable due to its high chlorine content. In this work, chlorine evolution behavior and the conversion mechanism during ASR pyrolysis between 480 and 600 °C were systematically studied. The experimental results for organic chlorine (Org-Cl) showed that released chlorinated gases were complex, and HCl only accounted for 35% of the gas phase products, while short-chain hydrocarbons with carbon atoms between two and four accounted for 52%. Chlorine was predominantly retained in the char, and Org-Cl was the primary contributor to the residual chlorine, accounting for over 50% of the char. The content of inorganic chlorine (InO-Cl) was low in the raw sample but significantly increased in the char. Through the distinction between organic and inorganic chlorine content in char, it was confirmed that Org-Cl could be converted to InO-Cl due to complex secondary reactions with metallic compounds. The conversion was favored by increasing the Org-Cl content and the temperature. Our findings clarified the evolution mechanism of chlorine and the transformation from Org-Cl to InO-Cl, thus providing guidance for chlorine regulation and the efficient recycling of metal resources.

Isolation of the elusive [Ru(bipy)3]+: a key intermediate in photoredox catalysis.

Photoredox catalysis has flourished in recent years, but due to its widespread utility applications have grown faster than mechanistic understanding. In this report we help to address this deficit by isolating and characterising one of the intermediates of the iconic photocatalyst [Ru(bipy)3]2+, and testing its initial photoreactivity towards common substrates.

Investigation on the co-combustion characteristics of multiple biomass and coal under O2/CO2 condition and the interaction between different biomass.

The co-combustion of coal and biomass in O2/CO2 conditions is a promising technology for CO2 capture and waste disposal. Little attention has been paid to the interaction between different biomass in co-combustion process, which is of great significance to the study of the co-combustion mechanism. The co-combustion behavior of coal and multiple biomass under isothermal conditions was characterized by thermogravimetric method, and the interaction between different biomass was investigated from the perspective of thermogravimetric and proximate analysis. It found that biomass blending could remarkably improve the combustion performance of coal. Compared to the theoretical prediction, the interaction between coal and biomass showed remarkably promoting effects when the coal was blended with different biomass. While the interaction between different biomass was weak. Moreover, the influence of proximate analysis on combustion characteristic parameters was studied by establishing the linear relationship between combustion characteristic parameters and proximate analysis. The effects of proximate analysis on characteristic time/S were divided into five categories, and it were mainly controlled by the interaction both between coal with biomass and between different biomass.

Products distribution and sulfur fixation during the pyrolysis of CaO conditioned textile dyeing sludge: Effects of pyrolysis temperature and heating rate.

Textile dyeing sludge (TDS) is a typical industrial solid waste whose amount surged with the textile industry's development. Pyrolysis treatment is a promising technique for TDS to realize harmless disposal and resource reuse. However, the high content of organic compounds would cause sulfurous pollutants emission, reducing the economic feasibility during pyrolysis. This study aimed to fill the knowledge gaps about the thermal behavior, products distribution, kinetics, and sulfur transformation during TDS pyrolysis in 350-575 â„ƒ with the heating rate of 60, 600, and 6000 â„ƒ/min, then investigate the sulfur fixation effect of CaO under representative conditions (350 â„ƒ, 650 â„ƒ with 60 â„ƒ/min, 6000 â„ƒ/min). The primary decomposition stage of TDS is observed in 127-557 â„ƒ, following the Avrami-Erofeev (n = 3) model, while the activation energy presents a convergent tendency with the increased heating rate. The pyrolysis temperature and heating rates impact the cracking of organic compounds, while a weakening effect is found for the sulfur distribution. CaO addition could efficiently realize sulfur fixation in char by absorbing sulfurous gas products, but SO2 escape appeared with the increased CaO fraction. Pyrolysis condition at 650 â„ƒ-60 â„ƒ/min with 10 wt% CaO addition is recommended to achieve high sulfur retention, and the sulfur transformation mechanism in char during the TDS pyrolysis with and without CaO is proposed. Our findings provide novel and fundamental insights into the efficient disposal and pollution control during TDS pyrolysis.

Preparation and formation mechanism of biomass-based graphite carbon catalyzed by iron nitrate under a low-temperature condition.

Graphite is a widely used industrial material, which experienced a marked shortage caused by the growing demand for electrode anode material and the increased costs for raw material. Graphitic carbon from biomass is a promising approach that will result in low-cost and efficient preparation. Herein, Fe(NO3)3 was selected as the catalyst for pine sawdust, and the effects of temperature and iron content on the graphitization of biochar were investigated. Additionally, the formation mechanism of the graphitic crystallite structure was explored. Results showed that the formation of pyrolysis gas increased with the increase in the amount of catalyst added or pyrolysis temperature. The change in pyrolysis gas, such as H2 and CO, was a critical auxiliary factor reflecting the conversion process. As temperature was increased from 600 °C to 800 °C, the solid products showed high graphitization and low solid yield. Graphite structure mainly formed at 700 °C because of the formation of Fe nanoparticles. The increase in the amount of catalyst could provide more reaction sites and promote the contact between Fe and C, showing that amorphous carbon is dissolved on Fe nanoparticles and precipitated into ordered graphitic carbon. On this basis, a mechanism of "carbon dissolution-precipitation" was proposed to explain the formation of graphite structure, and the whole pyrolysis process included the transformation of the iron element were analyzed.

Effects of molten salt thermal treatment on the properties improvement of waste tire pyrolytic char.

Pyrolysis is a technical means for waste tires recycling, which can promote the enrichment of carbon black and facilitate the subsequent recovery. However, carbon black particles aggregated and the inorganic impurities tended to be enriched in pyrolytic char during the waste tire pyrolysis process, which is not conducive to the substitution of commercial carbon black by pyrolytic char. In the present study, a novel method using molten salts thermal treatment was proposed for the impurities removal from pyrolytic chars with different characteristics. In addition, the proper thermal treatment conditions were further estimated to obtain better performance for the physical-chemical properties improvement of pyrolytic char. Six kinds of char samples were chosen to conduct molten salts thermal treatment (MSTT) experiments at 350, 400, and 450 °C. The experimental results show that MSTT can effectively remove the impurities of different pyrolytic chars, and the most optimum reaction conditions are at 400 °C, 2 h of reaction time, and molten salt/char ratio of 10:1. In addition, after MSTT, the pyrolytic char was depolymerized, and the average particle size reduced from 36.63 µm to 19.08 µm, the specific surface area increased from 49 m2/g to 73 m2/g. At the same time, the graphite carbon content of the pyrolytic char increased from 24.41% to 70.90%, and the hydroxyl content on the pyrolytic char surface increased significantly. In summary, the physical-chemical properties of waste tire pyrolytic char were improved by MSTT, which is close to the carbon black N550 level.

Feasibility study on co-processing of automobile shredder residue in coal-fired power plants via pyrolysis.

Facing the challenges of organic industrial solid waste (OISW) disposal, co-processing of OISW by power plants has become a developing trend. In order to avoid feeding problems of OISW and enhance the combustion adaptability of the furnace, pyrolysis coupled with incineration technology is proposed as a potential method. Among various OISW, automobile shredder residue (ASR) is regarded as a promising fuel due to its high heating value. In view of engineering application, the researches focused on the products' properties and economic evaluation under a wide range of heating rates which are insufficient. In this study, regarding the rapid pyrolysis by conducting the high-temperature flue gas as heating source in power plants, the pyrolysis behavior of ASR was correspondingly studied under a wide range of heating rates. The formation of volatiles and property's improvement were further investigated for generating high-valued oil. Results showed that the high heating rate is not only beneficial to the homogenization of pyrolytic products but also the aromatization in oil and radical generation in gases. Importantly, it also contributed to the cleavage of the single bond connected to the benzene ring and carbon-oxygen single bond for esters. By conducting the enhanced cracking of volatiles, the wax-like fraction was significantly reduced. In addition, the deoxygenation in oil (oxygen content decreased by 20 wt%) and high heating value of gases (increased by 73%) were improved. Our findings demonstrated the feasibility and economic efficiency for the co-processing of ASR in coal-fired power plants via pyrolysis and thus provide guidance for future commercial application.

Investigation and improvement of the desulfurization performance of molten carbonates under the influence of typical pyrolysis gases.

Co-pyrolysis with oxygen-lean waste tires could improve the quality of pyrolytic oil from the bio-wastes while H2S/COS generated during co-pyrolysis process has a negative impact on the utilization of oil/syngas as well as the flue gas pollution control. Compared to traditional wet desulfurization process, high-temperature desulfurization via molten carbonates could reduce heat loss and favor the recycling of captured sulfur. Notably, small-molecule pyrolytic gases might change the species of sulfur-containing gases and promote the re-emission of absorbed sulfur from the molten salts. To fully understand the effects of pyrolysis gases (H2/CO/H2O/CO2) on molten salts desulfurization efficiency as well as mutual conversion mechanism of H2S and COS, equilibrium compositions calculations and adsorption experiments were carried out in the present study. The results showed that H2/CO had few effects on molten salts desulfurization performance and mutual conversion of H2S/COS. In contrast, CO2 and H2O had obvious adverse effects on desulfurization efficiency through the transferring of free S2- into emitted sulfur-containing gases. More specifically, only a small amount of CO2 reacted with S2- to produce COS while more S2- was converted to H2S and released from the reactor outlet when H2O was introduced. Fortunately, the impact of H2O or CO2 on molten salts desulfurization could be weakened with the addition of CaCO3 by transferring the molten free S2- into precipitated CaS. Besides, multi-stage desulfurization units connected in series and parallel were proposed and estimated, which was confirmed to show good performance to maintain the high desulfurization efficiency from the complicated pyrolytic gases.

Effect of Total Dissolved Gas Supersaturation on the Survival of Bighead Carp (Hypophthalmichthys Nobilis).

To assess the effect of TDG on the survival of different sizes of pelagic fish, bighead carp (Hypophthalmichthys nobilis) were subjected to TDG supersaturated water at levels of 125, 130, 135, and 140%. The results showed that apparent abnormal behaviours and symptoms of gas bubble disease (GBD) were observed in bighead carp. The survival probability of large and small juvenile bighead carp declined with increasing TDG levels. The median survival time (ST50) values of large juvenile bighead carp were 74.97 and 31.90 h at 130% and 140% TDG, respectively. While the ST50 of small fish were 22.40 and 6.72 h at the same TDG levels. In comparison to the large juvenile bighead carp, the small juvenile bighead carp showed weaker tolerance to TDG supersaturated water. Furthermore, acute lethality experiments after chronic exposure to TDG were initiated to further investigate the effect of TDG on bighead carp. The juveniles were first subjected to 115% TDG supersaturated water for 96 h. After chronic exposure, live fish were immediately transferred to TDG supersaturated water at levels of 125, 130, 135, and 140%. The results demonstrated that no fish died under chronic exposure and few fish exhibited slight GBD symptoms. The ST50 values for bighead carp subjected to acute exposure after chronic exposure were 61.23 and 23.50 h at 130 and 140%, respectively. Compared with the bighead carp subjected to acute exposure, bighead carp subjected to multiple exposures were more vulnerable to TDG.