Environmental Functional Materials in Air Pollution

Table of Contents

1. Frontmatter

2. Chapter 1. Study on Carbon-Ash Separation of Coal Gasification Fine Slag by Flotation with Composite Collector

   Yuchen Xiao, Shiyong Zhao, Zhenni Yang

   Abstract

   Coal gasification fine slag (CGFS) produced by a Texaco coal water slurry gasifier in Shaanxi, China was taken as the research object. The carbon-ash separation of CGFS was carried out by flotation with composite collector. The raw material and the flotation product were characterized by XPS, BET, SEM–EDS, et al. analysis. The results showed that when the dosage of composite collector was 15 kg/t and MIBC was 4 kg/t, the flotation perfect index and the combustible recovery were 47.78 and 84.34%, respectively, which increased by 14.69 and 23.03% compared with dodecane as collector, but the concentrate ash content was not significantly reduced. XPS analysis shows that there are still a large number of hydrophilic groups on the surface of the unburned carbon in the tailings, and these hydrophilic groups hinder the mineralization process of the unburned carbon and collector, thus affecting the floating of residual carbon. BET and SEM analysis results showed that the specific surface area of the flotation concentrate was 303.50 m²/g and the pore structure was developed, and EDS analysis showed that a large number of fine-grained spherical inorganic matter was still filled in the pore structure of unburned carbon, which was the main reason why the concentrate ash content was still about 30%.

3. Chapter 2. Molecular Dynamics Simulation of the Sorption Behavior of Organic Pollutants by Organo-Montmorillonite

   Lan Zhang, Qiu Shen, Tao Ding

   Abstract

   Sorption is one of the main mechanisms by which montmorillonite is used in water pollution treatment. In this study, montmorillonite was used to adsorb phenolic pollutants in wastewater and to study the adsorption mechanism of the process. The sorption was analyzed for surfactants (CTMA⁺) and different pollutants (phenol/2-naphthol). It was found that in the aqueous environment, water molecules had some influence on the arrangement of the components including modifiers, inorganic cations and contaminants, and the above components were slightly more active than in the dry state. The modifiers arrangement shifted from a laminar to a tilted distribution with the increase of loading amount, and the main sorption sites for organic pollutants were shifted from the inner surface of organo-montmorillonite to the organic phase in the organo-montmorillonite. The free binding energy of phenol under MMT-1.0 loading is − 211.780, which is slightly lower than − 207.066 and − 204.147 under MMT-1.75 and MMT-0.25 loading. When 2-naphthol is used, the free binding energy of MMT-1.0 reaches − 343.38, which is much lower than that of − 272.51 and − 217.92 under the loading of MMT-0.25 and MMT-1.75, indicating that the adsorption effect of organic matter under the loading of MMT-1.0 is better and the adsorption effect of montmorillonite on 2-naphthol is stronger than that of phenol.

4. Chapter 3. Potential of Rice Husk Biochar in Cement Mortar for Carbon Capture and Storage

   Priscilla Fong Ern Gunn, Chiu Chuen Onn, Hwei Voon Lee, Kim Hung Mo

   Abstract

   Research on green alternatives from agricultural waste as cement substitutes has been significant. Biochar, with unique properties, can improve cementitious composites’ physical, mechanical properties and aiding carbon capture and storage. In this study, cement mortars were fabricated using rice husk biochar (RHB) at varying dosages - 10%, 20%, 30%, and 40% relative to the cement volume. The carbonation curing has been shown to greatly enhance the cement mortar’s compressive strength, with a maximum increase of 82%. However, a higher dosage of biochar resulted in reduced workability and increased permeable pore space. This study indicates that biochar derived from rice husk waste has the potential to be utilized as a substitute in cement mortar, contributing to waste reduction and offers a promising solution for carbon capture and storage.

5. Chapter 4. Catalytic Degradation of Tetracycline by Core–Shell CoMn@NC Nanoparticles Via Enhanced Peroxymonosulfate Activation

   Yuankang Bao, Xun Xu, Dongbai Xie

   Abstract

   This study synthesized core–shell structured CoMn@nitrogen-doped carbon (CoMn@NC) magnetic nanoparticles by annealing CoMn Prussian blue analog (PBA) precursors. The catalytic performance of the catalyst in activating peroxymonosulfate (PMS) to degrade tetracycline hydrochloride (TC) was investigated. Characterization of the catalyst using X-ray diffraction, and scanning electron microscopy revealed the presence of amorphous carbon, CoO, Co, and amorphous manganese species, with CoMn bimetallic particles encapsulated in nitrogen-carbon core–shell structures. At 25 °C and an initial pH of 6.2, with the addition of 50 mg/L catalyst and 200 mg/L PMS, complete degradation of 20 mg/L TC was achieved within 20 min.

6. Chapter 5. Kinetic Analysis of N-Desorption in Chemical Looping Ammonia Synthesis

   Zhongyuan Liu, Qingbo Yu, Jiatai Zhao

   Abstract

   This study examines how varying reaction temperatures influence the N-desorption process, along with the development of a kinetic model for the reaction. The results indicate that higher temperatures enhance the N-desorption reaction, and that the shrinking core model provides the best fit for describing the reaction kinetics. The activation energy associated with the N-desorption process is 330.52 kJ/mol.

7. Chapter 6. Investigation on the Condensation Effect of Particulate Matter Under the Action of Sound Waves in Different Working Conditions

   Tianli Jiang, Xiang Gao, Donglin Yang, Lintao Qi, Jin Wang

   Abstract

   The prevention and reduction of PM2.5 and other pollution particles is a major challenge environmental protection. The existing emission reduction methods are complex and costly, and secondary pollution needs to be dealt with. In this study, acoustic agglomeration technology is proposed to promote the accumulation of particles through acoustic waves. This method is environmentally friendly and efficient, and shows a good application prospect. Sound wave condensation technology promotes the relative movement of pollution particles through the strong sound field, and the fluid medium will produce periodic changes when the sound wave propagates. The difference in response of particles of different scales to this change leads to different motion speeds, and the collision polymerization probability between particles increases. After multiple collisions, the fine particles condense into larger particles, which settle under the action of gravity, effectively reducing the pollution particles in the air. The team carried out a simulation study, using the control variable method to explore the agglomeration efficiency of sound waves on particles under different working conditions. By applying acoustic waves with the same sound pressure level and different frequencies to particles, it is concluded that the effect of acoustic wave frequency on the agglomeration effect of particles is not a simple linear relationship, but there is an optimal frequency, which is between 600–1200 Hz, and the agglomeration effect of particles reaches the best in this frequency range. Then, the sound wave is controlled within the optimal frequency range, and the sound wave with different sound pressure levels is applied to the particles. The experimental results show that the sound pressure level is positively correlated with the condensation efficiency of the pollution particles, but its increase is not linear. When the sound pressure level is lower than 140 dB, the increase in condensation efficiency of pollution particles is not significant for each increase of 10 dB. Finally, the team designed the relevant device for experimental demonstration, which proved the correctness of the simulation conclusion and the reality of the method.

8. Chapter 7. System Design of Artificial Intelligence and Digital Twins for Smart Fusion Materials

   Pan Liu, Jian Wang, Zhangchun Tang, Zilong Yuan

   Abstract

   With the continuous development of fusion technology, the demand for smart fusion materials is becoming more and more urgent. Smart fusion materials are materials with intelligent sensing and response capabilities, capable of acquiring and feeding back changes in the physical state of fusion in real time. Such materials can help scientists better understand material behaviour during fusion and provide important real-time data support. However, traditional experimental approaches often fail to meet the demand for smart fusion materials, and a new system is needed to achieve this goal. The system design proposed in this paper includes a smart material module and a digital twin module. The smart material module is used to acquire material data and interact data with the digital twin module. This module can acquire physical parameters of the material such as temperature, pressure and deformation in real time through sensors and other technologies. These data can be transmitted to the digital twin module for processing and analysis through wireless transmission or wired connection. The system achieves real-time sensing and prediction of fusion materials through the smart material module and the digital twin module. Such a system can help scientists better understand the behaviour of materials during fusion and provide important support for the further development of fusion technology.

9. Chapter 8. Modeling Analysis of the Adsorption–Desorption Process of Activated Carbon Canister in On-board Refueling Vapor Recovery System

   Daming Liu, Yaqi Li, Xudong Zhen

   Abstract

   This study investigates the activated carbon canister within the On-board Refueling Vapor Recovery (ORVR) system for gasoline vehicles. A one-dimensional hydrocarbon adsorption simulation model, based on the Dubinin-Astakhov and linear driving force models, was validated against experimental data. The model demonstrates adaptability across various carbon types and canister dimensions. At the 2 g breakthrough point, butane distribution is uneven, particularly near the outlet, leaving some activated carbon underutilized. High desorption rates reduce residual butane, but slower rates prove more effective with equivalent inlet air volumes. Significant temperature fluctuations during adsorption/desorption impact reaction kinetics. Two strategies are proposed to enhance canister performance: (1) multi-port designs for uniform butane-activated carbon contact; (2) increased desorption rates with sufficient air supply. This research provides a theoretical basis and practical guidance for ORVR activated carbon canister design and optimization.

10. Chapter 9. Novel Insights into Anaerobic Digestion of Different Compositions in Lignocellulosic Biomass: Focus on Biomethane Production Potential, Kinetic Analysis, and Microbial Community Characteristics

    Xiteng Chen, Xinzi Wang, Ziqing Li

    Abstract

    In order to research biomethane production potential, and analyze microbial community characteristics of lignocellulosic biomass, microcrystalline cellulose, xylan, alkaline lignin, and corn straw were mixed with anaerobic granular sludge for anaerobic digestion. The cumulative methane production of MC, XY, and CS system was 285.23 ± 5.17 mL/ VS, 370.83 ± 14.60 mL/g VS, 172.06 ± 8.56 mL/g VS respectively. Cellulose and hemicellulose can be converted by microorganisms into biomethane. The biodegradability and dynamic model fitting results also revealed the anaerobic lag time of MC system was longer than XY, and CS system. In addition, the fermentation cycle of MC also was longer than XY and CS. T78, vadinCA02, Clostridium and Bacteroides played important roles in hydrolytic-acidification, and especially the relative abundance of Clostridium, a genus of cellulose-degrading bacteria, increased to 5.65% (MC), 3.65% (XY) and 2.84% (CS) respectively. Moreover, Methanosaeta and Methanobacterium were the two main anaerobic archaea in MC, XY and CS anaerobic digestion systems.

11. Chapter 10. Experimental Study on Water–Rock Coupling of Red Sandstone

    Juntao Zhu, Xiangmei Chen, Yongqiang Ren, Qi Liu, Zhihui Mi, Yingchun He, Wenlong Cao

    Abstract

    To elucidate the impact of wet-dry cycles on red sandstone in the Ordos region, experiments were conducted using a servo-hydraulic machine. Parameters such as uniaxial compressive strength, elastic modulus, strain corresponding to peak stress, and Poisson’s ratio were evaluated across various cycles. The study reveals a significant decline in uniaxial compressive strength, elastic modulus, and peak strain of red sandstone under wet-dry cycling. However, the effect on Poisson’s ratio remains minor. The findings provide valuable insights for engineering design and slope failure mechanism research.