Liquid Pollutants Research Articles

Interaction Mechanisms of POSS-based Adsorbents with VOCs, CO2, CH4, and H2O: Theoretical Insights and Prediction Method

The dual nature of Polyhedral Oligomeric Silsesquioxane (POSS), with its cage framework and substituent groups, enables diverse interactions with liquid and gaseous pollutants. While Quantum Mechanical (QM) methods have been used for simpler POSS variants, evaluating all possible combinations is impractical. This study aims to fill the knowledge gap on how the polarity of liquid pollutants and the structural features of POSS influence the efficiency of separating Volatile Organic Compounds (VOCs) from aqueous streams in wastewater treatment processes. Using a comprehensive dataset on liquid-liquid adsorption selectivities, we developed a predictive model for estimating VOC-VOC and VOC-water partition coefficients across 1.424 × 107 POSS variants, achieving accuracy comparable to expensive QM methods. This model enables users to design novel POSS molecules tailored for wastewater treatment or VOC recovery quickly and efficiently. We explored adsorption mechanisms for CO2, H2O, and CH4, focusing on interactions between the cage and adsorbates, as well as between substituents and adsorbates. Our findings highlight that substituents are crucial for gas adsorption, with their electrostatic properties being a significant factor. While all substituents exhibited strong CO2/CH4 selectivity, this selectivity diminishes in the presence of H2O. Additionally, gaseous pollutants are only effectively encapsulated when the POSS cage size exceeds T10. This work provides a framework for designing optimized POSS materials for specific separation applications, facilitating the efficient selection of structures for targeted gas and liquid capture.

Insights into the photocatalytic process of surface-platinized hierarchical anatase TiO2 nanoparticles by in-situ DRIFT analysis

BackgroundEnvironmental remediation researchers are challenged to unravel the mechanisms of dual-responsive photocatalysts for degrading pollutants in both liquid and gas phases. This study aims to provide comprehensive insights into the photocatalytic processes employed by surface-platinized hierarchical anatase TiO2 nanoparticles. The investigation includes an in-depth analysis of the associated mechanism through in-situ DRIFT analysis. MethodsUtilizing surfactant-assisted surface platinized TiO2 samples synthesized through soft-template and chemical reduction techniques, this study investigated their efficacy in the degradation of crystal violet dye (10 ppm) under irradiation from a 380.8 W mercury-xenon lamp. The photooxidation of gas-phase ethanol was subsequently examined using the DRIFT technique. Significant findingsThe Pt-deposited C-TiO2 nanoparticles exhibited an impressive photocatalytic dye degradation efficiency of 87.07 %, surpassing the performance of other synthesized catalysts. To elucidate the mechanism behind this enhancement, an in-situ DRIFT analysis was conducted using the photo-oxidation of ethanol. The enhanced efficiency can be attributed to the incorporation of Pt metal, which serves as an electron collector in the n-type TiO2 semiconductor, thereby prolonging electron lifetime. Additionally, the pivotal role of hydroxyl radicals and holes in generating intermediates was thoroughly examined through DRIFT analysis, providing comprehensive insights into the photocatalytic reaction and the reactive intermediate species involved.

Scanning glass microelectrode technique for investigating temperature-dependent electrical properties

Abstract Recent progresses in ionic current analyses related to micro- and nano-object sensing, electrochemical sensors, and liquid pollution monitoring have attracted significant attention. Micro- and nanoscale sensors with high spatial resolution and high signal-to-noise ratios are also effective for obtaining detailed understanding of ion transport phenomena. We have developed a glass microelectrode technique for measuring the electrical potential distribution by scanning through liquids. It enables us to directly evaluate electrical properties with a spatial resolution equal to the glass tip diameter, which is less than 1 μm. Herein, we optimize the channel and cell structures for the analysis of temperature-dependent properties, which allows us to measure the temperature dependence of conductivity and viscosity in the range of 303--333 K based on the Stokes--Einstein relation. The proposed method, which directly measures the spatial distribution of electrical potential, is suitable for analyzing conductivity, viscosity, and concentration without preprocessing calibration.

Bubbles Counting Using Organic Pollutants Degradation as a Probe

Relying on the fact that both of chemical and physical impacts of sonication are in strong relation to the number of acoustic cavities, the present paper introduces an innovative technique for the estimation of the number of active bubbles using the degradation of nonvolatile pollutants in the bulk liquid as a probe. The internal (gas pages) and external (liquid) bubble sonochemistry were simulated to track the radicals generation and use for nonvolatile pollutants degradation (in the liquid phase). To this end, COPASI® chemical kinetics software has been used for optimizing the acoustic bubble number density by linking the instantaneous bubble gas reaction (described by a bubble dynamic model accounting for the radical dissolution mechanism) and the aqueous free radicals degradation kinetics [i.e. concentration vs. time] of several nonvolatile organics (phenol, 4-chlorophenol, dyes…). Based on this strategy, the number density of active bubbles was determined for different operating circumstances (i.e. acoustic intensity, frequency, liquid temperature and saturation gas type). The performance of our method was evaluated by comparing our findings to those available in the literature, where an excellent agreement was established. Our technique showed that the number density monotonously goes up with increasing ultrasound frequency from 200 to 1140kHz, regardless of the experimental conditions used in this investigation. The opposite behavior has been obtained with the increase of the liquid temperature and acoustic intensity. Additionally, it has been noticed that the variation in the number of cavities with respect to the nature of saturating gas is frequency-dependent. At a frequency of 200kHz, the number of bubbles is in the order: O2>Ar>air. However, over this frequency (>200kHz), the number of acoustic bubbles is in the order: O2>air>Ar. On the other hand, it has been shown that below a frequency of ~860kHz, the variation of void fraction (ε) is synchronized with change in number density (N); nevertheless, over this value (>860kHz), these two parameters (N, ε) are no longer closely connected. As a result, in this case (>860kHz), the evaluation of number density from the total volume fraction of bubbles could not be directly performed without more information regarding the bubbles population, (e.g. size distribution, bubble-bubble interactions, bubbles deformation…etc.). Finally, the current proposed technique is flexible and can determine the number density of active bubbles for a wide range of operating conditions and circumstances.

Unraveling the synergism mechanistic insight of O-vacancy and interfacial charge transfer in WO3-x decorated on Ag2CO3/BiOBr for photocatalysis of water pollutants: Based on experimental and density functional theory (DFT) studies

Photocatalysis has been widely used as one of the most promising approaches to remove various pollutants in liquid or gas phases during the last decade. The main emphasis of the study is on the synergy of vacancy engineering and heterojunction formation, two widely used modifying approaches, to significantly alter photocatalytic performance. The vacancy-induced Ag2CO3/BiOBr/WO3-x heterojunction system has been fabricated using a co-precipitation technique to efficiently abate methylene blue (MB) dye and doxycycline (DC) antibiotic. The as-fabricated Ag2CO3/BiOBr/WO3-x heterojunction system displayed improved optoelectronic characteristic features because of the rational combination of dual charge transferal route and defect modulation. The Ag2CO3/BiOBr/WO3-x system possessed 97% and 74% photodegradation efficacy for MB and DC, respectively, with better charge isolation and migration efficacy. The ternary photocatalyst possessed a multi-fold increase in the reaction rate for both MB and DC, i.e., 0.021 and 0.0078 min−1, respectively, compared to pristine counterparts. Additionally, more insightful deductions about the photodegradation routes were made possible by the structural investigations of MB and DC using density functional theory (DFT) simulations. This study advances the understanding of the mechanisms forming visible light active dual Z-scheme heterojunction for effective environmental remediation.

A Study on the Adsorption of Rhodamine B onto Adsorbents Prepared from Low-Carbon Fossils: Kinetic, Isotherm, and Thermodynamic Analyses.

The aim of this study was to obtain a series of activated carbon samples by the chemical activation of low-rank coal. The precursor was impregnated with a NaOH solution. Activated carbons were characterized by determining their textural parameters and content of surface oxygen functional groups and by using an elemental analysis. The carbons were tested as potential adsorbents for the removal of liquid pollutants represented by rhodamine B. The effectiveness of rhodamine B removal from water solutions depended on the initial concentration of the dye, the mass of rhodamine B, and the pH and temperature of the reaction. The isotherm examination followed the Langmuir isotherm model. The maximum adsorption capacity of the rhodamine B was 119 mg/g. The kinetic investigation favored the pseudo-second-order model, indicating a chemisorption mechanism. The thermodynamic assessment indicated spontaneous and endothermic adsorption, with decreased randomness at the solid-liquid interface. The experiment revealed that a 0.1 M HCl solution was the most effective regenerative agent.

Migration and distribution characteristics of typical organic pollutants in condensable particulate matter of coal-fired flue gas and by-products of wet flue gas desulfurization system.

The wet flue gas desulfurization (WFGD) system of coal-fired power plants shows a good removal effect on condensable particulate matter (CPM), reducing the dust removal pressure for the downstream flue gas purification devices. In this work, the removal effect of a WFGD system on CPM and its organic pollutants from a coal-fired power plant was studied. By analyzing the organic components of the by-products emitted from the desulfurization tower, the migration characteristics of organic pollutants in gas, liquid, and solid phases, as well as the impact of desulfurization towers on organic pollutants in CPM, were discussed. Results show that more CPM in the flue gas was generated by coal-fired units at ultra-low load, and the WFGD system had a removal efficiency nearly 8% higher than that at full load. The WFGD system had significant removal effect on two typical esters, especially phthalate esters (PAEs), with the highest removal efficiency of 49.56%. In addition, the WFGD system was better at removing these two esters when the unit was operating at full load. However, it had a negative effect on n-alkanes, which increased the concentration of n-alkanes by 8.91 to 19.72%. Furthermore, it is concluded that the concentration distribution of the same type of organic pollutants in desulfurization wastewater was similar to that in desulfurization slurry, but quite different from that in coal-fired flue gas. The exchange of three organic pollutants between flue gas and desulfurization slurry was not significant, while the concentration distribution of organic matters in gypsum was affected by coal-fired flue gas.

Heterogeneous catalysis for the environment

<p>Anthropogenic climate and environmental changes increasingly threaten the sustainability of life on Earth, hindering the sustainable development of human societies. These detrimental ecological changes are driven by human activities that have elevated atmospheric levels of greenhouse gases and toxic substances, increased inorganic and organic pollutants in water bodies, and led to the accumulation of solid waste in soils. Over the next two to three decades, the impacts of climate change, water pollution, and soil contamination are expected to intensify, posing increasing risks to human health and global stability. Considering these trends, it is essential to implement robust mitigation and adaptation strategies. This paper analyzes environmental pollution problems from the perspectives of atmospheric, water, and soil contamination. It summarizes current research on heterogeneous catalysis for treating pollutants in gaseous, liquid, and solid phases, with an emphasis on the key challenges of applying these catalytic conversion technologies in cost-effective industrial settings. Finally, strategies for mitigating environmental pollutants via heterogeneous catalysis are discussed from the perspectives of material flow, energy flow, and data flow. This paper aims to offer scientific insights to enhance future research and practice in heterogeneous catalysis for environmental remediation.</p>

Assessment of the effect of drought and anthropogenic liquid pollution on the physicochemical quality of the waters of Oued Inaouene using the Water Quality Index (Taza, Morocco)

The Inaouene river, a tributary of the Oued Sebou, is subject to the effects of drought in the Mediterranean climate and pollution from raw wastewater. Assessment of water quality in this hydrosystem using the water quality index (WQI) calculated from 19 physico-chemical parameters (pH, T°, EC, DO, MES, NH4+, NTK, NO3-,SO4--, PO4-- ,PT, COD, BOD5, Cl-, Cr, Zn, Pb, Cu and Fe) over 3 hydrological cycles (May 2019 to June 2022) showed that upstream, water quality remains very poor, with no significant inter-annual variations, except for stations located on Oued Lahdar (WQI=35.11) and those downstream of Inaouène (WQI=43.71), where quality is good during the 2nd hydrological cycle. During the 1st and 3rd hydrological cycles, water quality deteriorated in the Inaouene (WQI>100), reflecting water quality unfit for consumption. Overall, the WQI values recorded are very high during the 3rd dry hydrological cycle. Moreover, the WQI varied significantly between the 3 cycles (p = 0.0006).

Preparation of a Stable Superhydrophobic Mortar Surface Using a One-Step Method.

Research efforts have intensified on developing superhydrophobic surfaces on concrete structures to limit the damage caused by the natural porosity and hydrophilicity of cementitious materials. However, the feasibility idea is impeded by the complex preparation process and weak adhesion/stability performance. Therefore, superhydrophobic coatings were rapidly prepared on mortar surfaces by a straightforward and effective one-step method using zinc oxide (ZnO) modified with stearic acid and epoxy resin. The microstructure, physical/chemical properties, hydrophobic properties, and stability of the coatings were systematically investigated. The experimental results showed that the water contact angle of the samples reached a maximum value of 164.2° and a sliding angle of 4.6° when the stearic acid content was 0.5 g. The water absorption of the coated superhydrophobic mortar was reduced by approximately 61% compared to that of ordinary mortar, and neither particulate pollutants nor liquid pollutants could contaminate the superhydrophobic mortar. The coating maintained a superhydrophobic state and exhibited good physical durability after sandpaper abrasion, tape peeling, and high-temperature resistance tests. The water cluster diffusion coefficient on surface of the ordinary coating was 0.1645 × 10-4 and 0.0328 × 10-4 cm2/s on surface of the modified coating after molecular dynamics simulation.

Microwave Heating for Synthesis of Carbonaceous Adsorbents for Removal of Toxic Organic and Inorganic Contaminants.

The residues obtained from the extraction of Inonotus obliquus fungus were used to produce carbonaceous adsorbents. The initial material was subjected to pyrolysis in a microwave oven. The adsorbents were characterized through elemental analysis, low-temperature nitrogen adsorption/desorption isotherms, and Boehm titration. The carbonaceous adsorbents were tested for the removal of NO2, methylene blue, and malachite green. The results indicated that the obtained carbonaceous adsorbents exhibited basic characteristics and possessed specific surface areas of 372 and 502 m2/g. The adsorption process of liquid contaminants was modeled using the single-layer Langmuir model. The maximum adsorption capacities were found to be 101 and 109 mg/g for methylene blue, and 75 and 77 mg/g for malachite green. The kinetic study demonstrated that the adsorption of methylene blue and malachite green was better described by a pseudo-second order model. The study affirmed that the adsorption of organic dyes onto the resultant carbonaceous adsorbents was both spontaneous and endothermic. The study also demonstrated that the presence of an air stream during the NO2 adsorption process and prehumidization of the adsorbent with humid air had a beneficial effect on the obtained sorption capacities. In conclusion, the study demonstrated that pyrolysis of the extraction residues from the fungus Inonotus obliquus yields highly effective, environmentally friendly, and cost-efficient carbonaceous adsorbents for the removal of both gaseous and liquid pollutants.

Studying properties of pervious concrete containing recycled aggregate loaded with TiO2/LDHs and its liquid pollutant purification

This paper endows recycled aggregate with photocatalytic properties considering its porous structure. It then prepares recycled-aggregate pervious concrete with photocatalytic–adsorptive synergistic functions to improve reusing construction and demolition waste and reduce the pollution of urban rainwater runoff. To this end, traditional photocatalyst TiO2 is modified by introducing hydrotalcite, layered double hydroxides (LDHs), and the calcined LDHs and TiO2 are mixed to form a composite photocatalytic material, i.e., TiO2/LDHs. Then, we composite different concentrations of TiO2/LDHs with the recycled aggregate by the soaking method to prepare recycled-aggregate pervious concrete. This work studies the effect of TiO2/LDHs on the physical and mechanical properties of recycled-aggregate pervious concrete. The purification performance of the pervious concrete containing TiO2/LDHs-loaded recycled aggregate in the photocatalytic–adsorptive synergistic degradation of liquid pollutants is also measured. In addition, a kinetic model is employed to explore the rate and mechanism of the photocatalytic–adsorptive synergistic degradation. Our findings indicate a significant enhancement in the material properties. Specifically, the addition of TiO2/LDHs led to an approximate reduction of 20% in both porosity and permeability, while concurrently augmenting the compressive strength by nearly 40%. The TL-0.8 specimens have the best physical and mechanical properties: the 28-day compressive strength, permeability coefficient, and porosity reach 27.4 MPa, 1.65 mm/s, and 14.69% respectively. The TL-0.6 specimens have the highest performance in degrading the methylene blue solution, and the degradation rate reaches 65%; the Langmuir pseudo-first-order kinetic model describes the degradation. The TL-0.8 specimens have the highest performance in adsorbing nitrate ions, and the removal rate reaches 56.8%; the adsorption follows the Lagergren pseudo-first-order kinetic model. The mechanism of the photocatalytic–adsorptive synergistic degradation shows that liquid pollutants are first adsorbed onto the surface of the recycled-aggregate pervious concrete, and photocatalytic reactions occur under the action of ultraviolet rays; then, the reaction products are desorbed from the concrete surface or diffuse into its pores, that is, the directional transfer of pollutants, realizing the purification of liquid pollutants.

A comparative study of DNAPL migration and transformation in confined and unconfined groundwater systems

To explore the migration and transformation process of dense non-aqueous liquid (DNAPL) pollutants’ multiphase flow, specifically nitrobenzene (NB), in confined groundwater (CG) versus unconfined groundwater (UG), a two-dimensional sandbox experimental device was designed and constructed. This involved constructing a vadose zone-UG- aquitard-CG structure, which was then subjected to different scenarios. Real-time analysis and numerical simulation methods were established and employed, with a particular focus on the detailed investigation results of actual contaminated site. The study found that when the same amount of NB was injected, the special structure of the CG layer resulted in a more pronounced reverse diffusion of NB in both the dissolved and NAPL phases. This was especially true for the dissolved phase, which was more likely to diffuse reversely. Meanwhile, CG did not directly interact with the vadose zone, and there was no loss of gas phase NB after the leakage in CG. As a result, higher concentrations of dissolved phase NB were generated, leading to the emergence of a larger area of NB contaminant plumes with CG flow. Importantly, the simulation study of the actual site and the laboratory experimental results were found to be validated, further validating the conclusion that direct leakage of NB into CG results in a higher concentration and larger area of dissolved phase contaminant plume, causing more serious pollution to the groundwater environment.

Combining Chitosan, Stearic Acid, and (Cu-, Zn-) MOFs to Prepare Robust Superhydrophobic Coatings with Biomedical Multifunctionalities.

There is an urgent need to develop a series of multifunctional materials with good biocompatibility, high mechanical strength, hemostatic properties, antiadhesion, and anti-infection for applications in wound care. However, successfully developing multifunctional materials is challenging. In this study, two superhydrophobic composite coatings with good biocompatibility, high mechanical strength, strong antifouling and blood repellency, fast hemostasis, and good antibacterial activity areprepared on cotton fabric surface by simple, green, and low-cost one-step dip-coating technology. The results discussed in the manuscript reveals that the two superhydrophobic composite coatings can maintain good mechanical stability, strong water repellency, and durability under various types of mechanical damage, high-temperature treatment, and long-term strong light irradiation. The coatings also exhibit good repellency to various solid pollutants, highly viscous liquid pollutants, and blood. In vitro and in vivo hemostatic experiments show that both composite coatings havegood hemostatic and anticlot adhesion properties. More importantly, this superhydrophobic coating prevents bacterial adhesion and growth and released Cu2+ and Zn2+ ions and chitosan to achieve bactericidal properties, thereby protecting injured skin from bacterial infection. The two superhydrophobic coatings enhance the antifouling, antiadhesion, hemostatic, and antibacterial functions of blood-repellent dressings and therefore have broad application prospects in medical and textile fields.

Effect of Temperature Variation on Band Gap Value in Thin Layers of Nano Photocatalyst Fe2O3/CuO/MnO2

Water is one of the primary needs of all living things in daily life. However, the availability of clean water is currently starting to decrease along with the decline in the quality and quantity of water in the environment. Industrialization and rapid economic development have caused concern due to the habit of disposing of waste without proper management. Attempts to get clean water free from pollution are to utilize technology with photocatalytic properties that can reduce liquid pollutants with Infra-Red light. The purpose of this study was to determine the optimum conditions of the band gap to photocatalyst by temperature variation. Fe2O3, CuO, and MnO2 are doped semiconductor materials for the application of photocatalyst properties. The materials were milled using a High Energy Milling (HEM-3ED) to obtain nanoparticle sizes. The synthesis was carried out by sol-gel and spin-coating methods to make a thin film in enhancing photocatalytic activity in industrial applications. Characterization was conducted using ultraviolet-visible (Uv-Vis) spectrophotometry analysis. The results showed that temperature affects photocatalyst properties and the band gap value obtained at a temperature variation of 400°C is 1.36 eV which is the most optimum semiconductor band gap energy.

Dynamic monitoring of leaking oil diffusion in porous media: An improved method assisting buried oil pipeline condition assessment

The environmental pollution caused by buried oil pipeline leakage is a typical non-aqueous phase liquid (NAPL) pollution accident. Therefore, it seems more reasonable to assess the condition of buried oil pipelines considering the potential contamination range. The law of oil diffusion in porous soil is very important for the safety management of buried pipelines and the remedy of leakage accidents. This paper proposes a dynamic observation technique of NAPL in porous media for buried oil pipeline leakage. A quantitative relationship between the diesel saturation and color components is established based on the theoretical analysis combined with 21 groups of dyed diesel experimental results. The accuracy of the observation technique is verified by a quantitative analysis of a series of discrete point samplings and a comparison of diesel volume in a diesel diffusion experiment. The results show that the combination of a specified saturation boundary and the color components S and I can effectively track the diesel diffusion fronts. The relative error between the calculated cumulative volume and the injected cumulative volume fluctuates around 5% at different times. This improved technology can effectively make up for the limitation of the traditional light transmission visualization (LTV) under low-intensity light and promote the study of NAPLs diffusion characteristics. Furthermore, the dynamic observation technique of NAPL in porous media for buried oil pipeline leakage monitoring can make a significant contribution to the improvement of the level of buried pipeline leakage accidents and remediation.

Multifunctional absorbents for oily pollution control and mechanistic insights with theoretical simulation

The fabrication of energy-efficient and high performing hydrophobic aerogels is highly desirable for addressing oil-based liquid pollution. The implementation of the aerogel adsorption process requires a comprehensive understanding of the macro-, micro-, and molecular-level mechanisms involved. To achieve this goal, molecular simulations can be employed to investigate the adsorption forces at the molecular level. Here, the cellulose extracted from Salvia miltiorrhiza Bunge residues (DS) were employed as natural building blocks to synthesize DS aerogel (DS-A) and subsequently silylated with methyltrimethoxysilane (MTMS). The resulting silylated DS aerogels (SDS-A) exhibited an exceptional adsorption capacity (25–105 g/g), endurable hydrophobicity, and a rapid oil adsorption rate of 5 s, with 2 wt% of DS cellulose (DS-C) and a porosity of 99.56%. Subsequently, the interactions were investigated between the silylated aerogel and oily liquids by means of docking, molecular dynamics (MD), and molecular mechanics-generalized Born surface area (MM-GBSA). Lipophilic energy and van der Waals energy surpassed Coulomb force in silylated cellulose/chlorobenzene complexes (−10.8 kcal/mol, −15.9 kcal/mol) and silylated cellulose/n-butyl acetate complexes (−4.3 kcal/mol, −17.1 kcal/mol). Molecular simulations revealed that van der Waals and hydrophobic interactions played crucial roles in adsorption. During the process, the adsorption mechanism was investigated at the molecular level, contributing to the understanding of silylated cellulose aerogel-based research. Moreover, the SDS-A demonstrated chemical durability with NaCl, NaOH, HCl, and oily liquids, as well as mechanical wear resistance without hydrophobic variation. Oil spill remediation results indicated that the aerogels could effectively facilitate continuous oil recycling from contaminated water in both artificial-driven and pump-driven experiments. This research provides novel insights into innovative solutions for oil-based liquid treatment technologies and future rational research.

A Nanophotocatalyst of ZnO/CuS with Photothermal Effect, Superhydrophobicity and Self-Healing Function

Photothermal-assisted photocatalysis is a novel catalytic technology that can not only utilize both light energy and light heat, but also simultaneously incorporate superhydrophobicity and self-healing ability into photocatalysts. It represents a significant advancement in efficient photocatalytic degradation of water pollution. Here, by incorporating the semiconductor photothermal agent CuS on the outer layer of ZnO nanoflowers, the deposited CuS layer exhibits an outstanding photothermal effect under near-infrared light irradiation, which can absorb infrared light and convert it into heat energy, enhancing the performance of the ZnO nanoflowers in situ. Meanwhile, a photothermal conversion surface material with self-healing superhydrophobicity is prepared by using a mixture of beeswax and polydimethylsiloxane. The broad light absorption ability and enhanced charge transfer accelerate the photocatalytic efficiency, in addition, the incorporation of superhydrophobicity enables resistance to corrosive liquid pollution and repairs its superhydrophobicity damage by beeswax migration to provide lasting protection. The degradation rate of MB is as high as 98% within 80 min. Finally, the mechanism of photothermal effect in photocatalysis and the mechanism of self-healing superhydrophobicity are proposed. This work innovatively integrates photothermal effect and self-healing superhydrophobic function into photocatalytic degradation of water pollution technology, which broadens the scope of improving photocatalytic performance and extends the photocatalyst operation life to a certain extent.

Removal of PM and oil mist from automobile exhaust by a “hamburger” structured conjugated microporous polymers membrane

The purification treatment of automobile exhaust has attracted great attention because of the severe harm of automobile exhaust to the global environment and human health. Herein, inspired by capillarity, we adopted a very simple face-to-face constrained growth method to prepare a conjugated microporous polymers membrane (C-CMPs-M) with a “Hamburger” structure through Sonogashira-Hagihara (S-H) coupling reaction for purification and filtration of gaseous, solid and liquid pollutants in automobile exhaust. Thanks to such a special structure, the C-CMPs-M−1 membrane shows an extremely high efficiency of capture and interception of PM2.5 and PM10 (greater than99.5 %) and PM0.3 (greater than95%) in the exhaust gas obtained at different engine speeds. Unlike those hydrophilic filtration materials which suffer the drawback of less tolerance in high humidity conditions, the unique superhydrophobic chemistry of the CMPs membrane makes it possible to efficiently intercept PM under high humidity conditions, and the filtration efficiency basically remains unchanged within 10 h. More interestingly, the super lipophilicity of the membrane endows it excellent oil absorption performance, e.g., high absorption of 907.61 % of its own weight for engine oil was detected and consequently good oil retention performance was also obtained. It also has a strong absorption performance for the unburned oil mist ejected from the exhaust. Based on its ideal porous structure, high interception efficiency, and good physicochemical stability at high humidity and high temperatures conditions, therefore, our C-CMPs-M−1 shows great potential in automobile exhaust purification applications.

Efficient capture of mercury ions by a novel organic melamine polymer

Mercury, as a heavy metal pollutant, severely threatens human health and the environment. In this work, a novel porous polymeric material, MMP (melamine polymer), was prepared using melamine as a precursor to removing Hg2+ from aqueous solutions. The characterization of the material showed that the MMP exhibited a two-dimensional folded sheet structure with a high specific surface area and pore size and was amorphous. FT-IR spectra showed the presence of amide bonds, which proved that the MMP was successfully synthesized and had good stability. The reaction kinetics and proposed secondary kinetics of the system after different adsorption times of MMP in mercury nitrate solution found that the adsorption rate of MMP could reach more than 90% at a concentration lower than 2000 mg·L−1. The removal capacity of saturated mercury ions was 2018.1 mg·g−1. Furthermore, it had good adsorption performance for mercury ions in a wide range of pH. The MMP has a high adsorption capacity and high adsorption rate for mercury ions, which is well demonstrated. The development of the material has a specific guiding effect on the existing treatment technology of mercury waste liquid. It provides a new method to solve the problem of mercury waste liquid pollution in functional factories.