Production Of Industrial Chemicals Research Articles

Machine Learning Molecular Dynamics Shows Anomalous Entropic Effect on Catalysis via Surface Pre-melting of Nanoclusters.

Due to the superior catalytic activity and efficient utilization of noble metals, nanocatalysts are extensively used in the modern industrial production of chemicals. The surface structures of these materials are significantly influenced by reactive adsorbates, leading to dynamic behavior under experimental conditions. The dynamic nature poses significant challenges in studying the structure-activity relations of catalysts. Herein, we unveil an anomalous entropic effect on catalysis via surface pre-melting of nanoclusters through machine learning accelerated molecular dynamics and free energy calculation. We find that due to the pre-melting of shell atoms, there exists a non-linear variation in the catalytic activity of the nanoclusters with temperature. Consequently, two notable changes in catalyst activity occur at the respective temperatures of melting for the shell and core atoms. We further study the nanoclusters with surface point defects, i.e. vacancy and ad-atom, and observe significant decrease in the surface melting temperatures of the nanoclusters, enabling the reaction to take place under more favorable and milder conditions. These findings not only provide novel insights into dynamic catalysis of nanoclusters but also offer new understanding of the role of point defects in catalytic processes.

Design-build-test of recombinant Bacillus subtilis chassis cell by lifespan engineering for robust bioprocesses

Microbial cell factories utilize renewable raw materials for industrial chemical production, providing a promising path for sustainable development. Bacillus subtilis is widely used in industry for its food safety properties, but challenges remain in the limitations of microbial fermentation. This study proposes a novel strategy based on lifespan engineering to design robust B. subtilis chassis cells to supplement traditional metabolic modification strategies that can alleviate cell autolysis, tolerate toxic substrates, and get a higher mass transfer efficiency. The modified chassis cells could produce high levels of l-glutaminase, and tolerate hydroquinone to produce α-arbutin efficiently. In a 5 L bioreactor, the l-glutaminase enzyme activity of the final strain CRE15TG was increased to 2817.4 ± 21.7 U mL−1, about 1.98-fold compared with that of the wild type. The α-arbutin yield of strain CRE15A was increased to 134.7 g L−1, about 1.34-fold compared with that of the WT. To our knowledge, both of the products in this study performed the highest yields reported so far. The chassis modification strategy described in this study can Improve the utilization efficiency of chassis cells, mitigate the possible adverse effects caused by excessive metabolic modification of engineered strains, and provide a new idea for the future design of microbial cell factories.

[Determination of nine aromatic amines in water by cloud point extraction-gas chromatography-mass spectrometry].

Aromatic amines are a class of compounds bearing amino groups on their benzene rings; these compounds are important raw materials for the industrial production of rubber chemicals, pesticides, dyes, pharmaceuticals, photosensitive chemicals, and agricultural chemicals. Research has revealed that some aromatic amines teratogenetic, carcinogenic, and mutagenic properties. Given the high toxicity and potential harm caused by aromatic amines, monitoring their levels in water sources is critical. Aromatic amines are among the 14 strategic environmental pollutants blacklisted in China, and assessing their exposure levels is essential for protecting human health and the environment. At present, the standard method for detecting aromatic amines in water is liquid-liquid extraction-gas chromatography-mass spectrometry (LLE-GC-MS). However, this method has the disadvantages of large sample size requirement, complex operation, long analysis time, and high reagent consumption. In this study, instead of traditional LLE technology, cloud point extraction (CPE) technology was used in combination with GC-MS to establish an efficient, sensitive, and environment-friendly method for the detection of nine aromatic amines, namely, 2-chloramine, 3-chloramine, 4-chloramine, 2-nitroaniline, 3-nitroaniline, 4-nitroaniline, 1-naphthylamine, 2-naphthylamine, and 4-aminobenzene, in water. Triton X-114 was used as the extraction agent. The main experimental parameters were optimized using a single-factor optimization method. The aromatic amines in various water samples were quantitatively analyzed using GC-MS. The nine aromatic amines were separated on a DB-35 MS capillary column (30 m×0.25 mm×0.25 μm). The mass spectrometer was operated in selected ion monitoring (SIM) mode, and quantitative analysis was performed using the internal standard method. The results demonstrated that all nine aromatic amines could be completely separated within 16 min and had good linearities within accurate mass concentration ranges, with correlation coefficients (R2) greater than 0.998. The limits of detection (LODs) and quantification (LOQs) of these aromatic amines in water were 0.12-0.48 and 0.40-1.60 μg/L, respectively. The accuracy and precision of the method were assessed via the determination of aromatic amines in surface water of drinking water sources, offshore seawater, wastewater of the typical printing and dyeing industry at levels of 2.0 and 10.0 μg/L. The recoveries of the aromatic amines in surface water of drinking water sources were 81.1%-109.8%, with intra-day and inter-day relative standard deviations (RSDs) of 0.7%-5.2% (n=6) and 1.6%-6.2% (n=3), respectively. The recoveries of the aromatic amines in offshore seawater were 83.0%-115.8%, with intra-day RSDs (n=6) of 1.5%-8.6% and inter-day RSDs (n=3) of 2.4%-12.2%. The recoveries of the nine aromatic amines in wastewater of the typical printing and dyeing industry were 91.0%-120.0%, with intra-day RSDs (n=6) of 2.9%-12.9% and inter-day RSDs (n=3) of 2.5%-13.1%. The established method was used to detect nine aromatic amines in actual water samples. No aromatic amines were detected in the surface water of drinking water sources or offshore seawater samples. However, 2-chloramine, 4-chloramine, and 4-aminobenzene, which are frequently used in the printing and dyeing industry, were detected in the wastewater of the typical printing and dyeing industry samples. The proposed method offers the advantages of simple operation, high sensitivity, low cost, low organic reagent requirement, and good repeatability. Thus, this method provides reliable technical support for studying the residual status and environmental behavior of aromatic amines in water.

Valorization of Lignocellulosic Molecules through Homogeneous Ru‐Catalyzed C−C and C−N Bond Forming Reactions

AbstractA sustainable upgrading of renewable bulk materials, obtained by decomposition of biomass lignocellulose, could facilitate their use in the industrial production of chemicals. Homogeneous ruthenium catalysis plays a fundamental role in this area. The review deals with the upgradation of lignocellulosic molecules through the formation of new C−C and C−N bonds. Selected examples of catalytic bond forming reactions reported until mid of 2023, include: (a) dehydrogenative based couplings of alcohols, (b) reductive amination of carbonyl compounds, (c) direct C−H functionalization of (hetero)aromatic compounds. These approaches fulfill the requirements of sustainability: application occurs without any previous substrate activation, thus reducing the production of waste. New chemicals containing the intrinsic molecular structure of lignocellulose substrates, showed a broad range of applications: green fuels, hydrogen carriers, monomers of polymers, intermediates of fine chemicals and pharmaceuticals. The results discussed in the review could inspire the reader to improve the valorization process, in terms of bio‐substrate scope as well as product complexity, through more strategic applications of the catalytic methods.

Potential of Deep Eutectic Solvents in the Extraction of Organic Compounds from Food Industry By-Products and Agro-Industrial Waste

Global food waste has a huge impact on the environment, as it is a source of greenhouse gas emissions and wasted natural resources. Across the world, over 30% of food is lost or wasted each year. Aside from this, the food industry, as well, is one of the biggest sources of agro-industrial waste and by-products, which can be valorized and used for different purposes. Such waste is a good source of bioactive organic compounds that can be extracted without altering their properties, where deep eutectic solvents can serve as green solvents and as an excellent replacement for volatile organic solvents. Isolated compounds can be used in innovative food production, chemical production, cosmetics and other industries. Deep eutectic solvents have attracted extraordinary attention due to their advantages such as environmental friendliness, availability and easy preparation, easy handling and utilization of non-toxic components for their formation. Due to these properties, they are a greener alternative to classic organic solvents for many processes, including extractions. In this paper, we review the utilization of deep eutectic solvents as potential green media for the extraction of organic compounds such as polyphenols, carbohydrates, proteins and alkaloids from by-products of the food industry and from agro-industrial waste.

Influence of organic matters on the adsorption-desorption of 1,2-dichloroethane on soil in water and model saturated aquifer.

1,2-Dichloroethane (1,2-DCA) is a typical organic chlorinated compound largely utilized in chemical manufacturing and industrial production and also a common pollutant in organically contaminated sites. The adsorption of 1,2-DCA on soil grains significantly influences its environmental fate and removal process. This study investigated the influence of fulvic acid (FA) and humic acid (HA) on the adsorption-desorption of 1,2-DCA in solid-liquid interfaces in water or constructed porous media. Experimental findings demonstrated the influence of organic matter on the adsorption of 1,2-DCA at the solid-water interface. 1,2-DCA adsorption increased in the FA or HA-treated soils when organic matter was present on the solid surfaces. The 1,2-DCA adsorption in the mixture of FA and HA was slightly lower than that in single organic acids, depending on the binding of FA and HA to the soil grains/colloids. Basic conditions reduced the adsorption of 1,2-DCA on soils, whereas acidic conditions enhanced adsorption due to the increased interactions via adsorption sites and hydrogen bonds. Conversely, the presence of organic matter in solutions (liquid phase in constructed porous media) will reduce the adsorption of 1,2-DCA on solid surfaces and increase the transport in the model aquifer. The combination of FA, HA, and rhamnolipids is helpful for the removal of 1,2-DCA from solid surfaces. Additionally, because of the enhanced desorption, the risk of 1,2-DCA contamination in groundwater can be increased when the organic matter or surfactant is present in the liquid phase if the eluent is not collected. This study helps to better understand the cooperative interaction of soil organic matter and chlorinated hydrocarbons at solid-water interfaces and the environmental fate and potential removal strategies of chlorinated hydrocarbons in contaminated sites.

중력모형을 활용한 우리나라 주요산업의 수출결정요인 비교 분석

Purpose - This study aims to derive export determinants for each major industry in Korea using a gravity model, and through this, suggest factors affecting the competitiveness of each industry.
 Design/Methodology/Approach - Using a gravity model, this study used annual data from 1995 to 2022 and conducted a panel analysis on the top 10 major export destination countries of Korea. The industries to be analyzed were agricultural and fishery products, chemical industrial products, iron and metal products, machinery, and electronic products.
 Findings - As a result of analyzing Korea’s major export determinants by industry using a gravity model, it was found that the per capita GDP (PGDP), which can determine the income size of the other country, gross national income (GNI) of the other country, and the population of the trading partner (POP), which can determine the size of the economy, had a positive (+) effect on chemical industrial products and machinery, and the distance variable showed negative effects on all industries except machinery.
 Research Implications - The larger the income and economy of Korea’s major trading partners, the greater the impact on exports. However, it was analyzed that the conclusion of an FTA had a positive (+) effect on agricultural, forestry, and fisheries products and steel and metal products, and the economic growth rate of trading partners had a positive effect on machinery and electronic products. The analysis results suggest that there are differences in export determinants by major industry, which requires an approach of customized export strategies by industry.

ИМПОРТОЗАМЕЩЕНИЕ В УСЛОВИЯХ САНКЦИЙ НЕДРУЖЕСТТВЕННЫХ СТРАН КАК ФАКТОР ПОВЫШЕНИЯ ЭКОНОМИЧЕСКОЙ БЕЗОПАСНОСТИ ГОСУДАРСТВА

In modern conditions of growing globalization, the interdependence of the national economies of different countries of the world is deepening, simultaneously with the specialization of each country in certain industries and products. However, the global interdependence of economies leads to a situation where changes in operating conditions in the foreign market of one country lead to significant economic problems in other partner countries. We can talk about the policy of protectionism and international sanctions. Analyzing the dynamics of imports in the context of the main importing countries, it was found that in 2021 there was a significant decrease in imports of goods from “unfriendly” countries, while imports from China increased by 47% and currently account for almost one-quarter of all imports. At the same time, it was noted that there is import dependence on imported machinery, equipment and vehicles; this group accounts for more than 48% of imports. The same can be said about the products of the chemical industry (rubber for the most part) and food products. Although in the last group a slight decrease in dependence can be noted. There is a decrease in dependence on imports for the group of consumer goods, while at the same time there is a high dependence for the group of intermediate goods, such as semi-finished products, components for production, etc. In recent years, there has been a steady increase in the production and substitution of imported goods in agriculture, in particular in livestock farming. The main directions for developing an export-oriented import substitution policy include: implementing an effective trade policy, investing in research and development, infrastructure development, developing a qualified workforce, market diversification, export lending, and introducing environmentally sustainable practices.

Formation of the innovative pole of Atyrau region development

Concepts such as growth poles and growth centres used to be interpreted as aggregate concentrations of population, natural resources, industries and services, and geographically as cities and development centres, but are now also referred to as free economic zones and technopoles. Despite the fact that the largest companies in the oilgas industry are located in Atyrau region, the manufacturing industry is not developed. There is a need to identify the growth poles and the formation of organisational and economic forms of their development in increasing the share of innovative production and activities in the oilgas chemical industry in the Atyrau region economy, occupying such unique resources as hydrocarbon raw materials. The formation of clusters in the regions will contribute to attracting investments in priority areas, activation of innovation activity, increasing export potential, making structural changes in the region. A relevant issue is the effectiveness of creating cluster structures in Atyrau region. Kazakhstan can become a real subject on innovative cluster development, offering products both on domestic and foreign markets in the raw materials direction. The prerequisites for the creation of innovation clusters on the study of economic and innovation potential in Atyrau region are considered. This article is devoted to the identification of theoretical and methodological aspects of the formation of growth poles in the development of the region's economy. The main purpose of this study is to substantiate the formation of innovation growth poles in Atyrau region. The authors conducted quantitative and qualitative analysis, assessment of economic, as well as Atyrau region innovation potential, determined the innovation activity of Atyrau region economic entities.

On the History of Developing Catalysis in Ukraine (1850s–1980s)

The article is dedicated to the history of developing highly effective catalysts in the leading scientific institutions of Ukraine and explores the prerequisites for developing theories in physical chemistry, in particular those related to kinetics and catalysis. It highlights the significance of scientific discoveries at the turn of the 19th and 20th century and their application by native scientists to advance theoretical development in the field of chemistry. Special attention is paid to the works of Lev Pisarzhevskii, focusing on his advancements in electronic chemistry and, in particular, the electronic theory of catalysis. The article also outlines current challenges in creating highly efficient catalysts for the chemical and light industry, emphasizing the importance of such indicators of catalysts as activity and selectivity. Drawing on historical, scientific and patent data, the study investigates the process of creating a highly efficient catalyst for obtaining acrylic acid from acrolein. This catalyst holds a great ractical importance for the production of various polymers in industrial conditions. It is shown that, as a result of research conducted by native scientists of the Institute of Physical Chemistry of the Academy of Sciences of the Ukrainian SSR and the Chemistry Department of Kyiv State University, the catalyst K-2-5 was developed. The catalyst has good indicators for the industrial production of acrylic acid from acrolein. The authors also highlight works studying the properties of the obtained catalyst, specifically its porous structure, which is an important factor in catalytic processes. They extensively focus on the kinetic indicators of catalytic reactions that occur when using this catalyst. The article also emphasizes the relevance of these developments for advancing research in catalysis and chemical industrial production.

Ion injection bipolar membrane electrodialysis realizes over 8 mol/L NaOH conversion from a brine stream

AbstractThe chlor‐alkali process is currently the predominant technology for caustic soda production but has several major challenges, such as enormous energy demand and supply–demand imbalance between NaOH and Cl2 in downstream industries. Herein, we propose a novel ion‐injection bipolar membrane electrodialysis (IJBMED) system that is capable of boosting water splitting in a bipolar membrane with an ultrahigh current density while omittance concentration polarization in anion‐ and cation‐exchange membranes. The results indicate that the IJBMED approach enables one‐step conversion of the NaCl‐containing brine stream into 8.12 mol/L NaOH with specific energy consumption of 0.79 kWh/kg NaOH (23 wt.% → 25 wt.%), compared to 2.15 kWh/kg NaOH (28 wt.% → 30 wt.%) for the chlor‐alkali process. The advantages of low energy consumption and omittance of chlorine emissions suggest that IJBMED might be a promising alternative to the chlor‐alkali process, revealing a new route to reshape the chemical industry for caustic soda production.

Study on material structure design, selective adsorption mechanism, and application for adsorption recovery of oil substances in coal chemical wastewater

In response to the problem of high emulsified and dissolved oils being difficult to recovery from coal chemical wastewater (CCW), this study specifically constructed a non-polar, macropore, and hydrophobic adsorption material (pSt-X) based on the main components of these two oils (aromatics and phenols) for selective recovery. The results revealed that pSt-X had an adsorption capacity of 215.52 mg/g, which had remained stable for multiple recycling sessions, with an adsorption capacity constantly above 95 %. The pSt-X has significantly larger particle size (0.7 mm–1.2 mm), which simplifies the process of adsorption regeneration and effectively prevents the loss of the adsorbent powder problem. The pSt-X adsorbent demonstrated remarkable selectivity towards dissolved and emulsified oils, exhibiting removal rates of 90.2 % and 81.7 %, respectively. Moreover, pSt-X proved remarkable selectivity in removing aromatic hydrocarbons (AHs) and phenols, with impressive removal rates of 77.8 % and 85.9 %, respectively. The selective separation mechanism of pSt-X for oil substances was further analyzed, indicating that its selective adsorption of oils was primarily driven by hydrophobic, π-π, and hydrogen bonding interactions owing to its non-polar and macropore structure and hydrophobic properties. The results of this study provide solid theoretical support for green and low-carbon recovery of oil substances in CCW and are of positive practical importance for clean production in the coal chemical industry.

Dynamic nonlinear soft sensor modelling method using linear slow feature analysis and least squares support vector regression for batch processes

AbstractData‐driven soft sensor models have been extensively utilized in industrial processes. Batch processes are usually employed to manufacture low‐volume and high value‐added products in chemical, materials, and pharmaceutical industries. The most distinctive features of batch process lie in nonlinear, repetition, and slow time varying characteristics. In this paper, a data‐driven soft sensor modelling method based on linear slow feature analysis (LSFA) and least squares support vector regression (LSSVR) is proposed. In this method, LSFA was used to effectively capture the driving force behind the data features that change as slowly as possible. Then, a LSSVR model was constructed between the extracted slow feature variables and quality variables. Finally, a numerical example, industrial penicillin fermentation processes, and cobalt oxalate synthesis process were utilized to confirm the prediction accuracy and model reliability of the proposed approach.

Enhancing Tm3+ upconversion via engineering interfacial strain for selective and sensitive MO sensing

Methyl orange (MO) is a widely used organic dye in industrial chemical production and biomedical research. However, its presence also poses potential risks to the environment and public health. The current MO sensing methods face numerous challenges such as low detection efficiency, expensive equipment, and complex operation. In this study, we propose a detection scheme based on heterostructure upconverting nanocrystals (UCNCs), where BaYF5:20Yb/0.5 Tm@SrYF5 UCNCs function as the energy donor, while the organic molecule methyl orange acts as the electron acceptor to quench the fluorescence emission band. The brightness and UC efficiency of NCs is significantly improved by engineering the interfacial strain. Specifically, the UC intensity of the BaYF5:Yb/Tm@SrYF5 core/shell NCs, exhibited a substantial increase of approximately 425-fold compared to that of the core NCs. The detection limit is measured to be about 0.25 μM, which is better than most reported fluorescence sensors. These results highlight the significant application prospects of fluorescence detection technology in the field of environmental safety.

Role of Additives: Modified Hemihydrate Phosphogypsum Morphology and Enhanced Filtration Performance of Wet-Process Phosphoric Acid.

The morphology of hemihydrate phosphogypsum crystals is of vital importance in the hemihydrate-dihydrate (HH-DH) wet-process phosphoric acid production for high filtration strength. The morphology of hemihydrate phosphogypsum is commonly needlelike due to the strong acidic crystallization environment, which is unfavorable to the following filtration process. In this study, the crystal habit of hemihydrate phosphogypsum with a large aspect ratio was skillfully modified by additives to achieve a higher filtration strength. d-Glucitol (DG) reduces the theoretical aspect ratio of hemihydrate phosphogypsum crystals from 2.076 to 1.583 by interacting with the (002) face of CaSO4·0.5H2O preferentially, and poly(vinyl alcohol) (PVA) facilitates the aggregation of small grains to gather into a clusterlike structure. The modified morphologies of hemihydrate phosphogypsum have a lower bulk density and a larger porosity of the formed filter cake, which increases the filtration strength up to 45.9% when DG is added. Our work provides an in-depth explanation of the evolution mechanism of hemihydrate phosphogypsum morphology with the additives and its influence on the filtration performance. The improved filtration strength would reduce the water content of hemihydrate phosphogypsum and relieve the storage pressure of the phosphogypsum slag dump, which is meaningful to the clean production and process emission reduction of the phosphorus chemical industry.

From Rags to Riches: Exploiting the Calvin‐Benson‐Bassham Cycle for Biomanufacturing

AbstractIndustrial chemical production largely relies on fossil fuels, resulting in the unavoidable release of carbon dioxide (CO2) into the atmosphere. The concept of a circular carbon bioeconomy has been proposed to address this issue, wherein CO2 is captured and used as a raw material for manufacturing new chemicals. Microbial cell factories and, in particular, autotrophic microorganisms capable of utilizing CO2 as the sole carbon source, emerged as potential catalysts for upcycling CO2 to valuable products. The Calvin‐Benson‐Bassham cycle (CBBc), the best‐known CO2 fixation pathway, is widely distributed in Nature. While extensively studied, microbial engineering programmes based on the CBBc remains relatively underexplored. In this review, we discuss avenues towards biotechnological exploitation of the CBBc to engineer CO2‐utilizing microbial cell factories, with a focus on chemically‐derived electron donors. We also highlight the advantages and challenges of implementing the CBBc in heterotrophic microbial hosts and its potential to advance a true circular carbon bioeconomy. Moreover, based on the pathway's architecture, we argue about the ideal value‐added products to generate from this metabolic route. Altogether, studying and engineering the CBBc in both natural‐ and synthetic‐autotrophs will enhance our understanding on this CO2 fixation pathway, enabling further exploration of biomanufacturing avenues with CO2 as feedstock.

Structural analysis of wild-type and Val120Thr mutant Candida boidinii formate dehydrogenase by X-ray crystallography.

Candida boidinii NAD+-dependent formate dehydrogenase (CbFDH) has gained significant attention for its potential application in the production of biofuels and various industrial chemicals from inorganic carbon dioxide. The present study reports the atomic X-ray crystal structures of wild-type CbFDH at cryogenic and ambient temperatures, as well as that of the Val120Thr mutant at cryogenic temperature, determined at the Turkish Light Source `Turkish DeLight'. The structures reveal new hydrogen bonds between Thr120 and water molecules in the active site of the mutant CbFDH, suggesting increased stability of the active site and more efficient electron transfer during the reaction. Further experimental data is needed to test these hypotheses. Collectively, these findings provide invaluable insights into future protein-engineering efforts that could potentially enhance the efficiency and effectiveness of CbFDH.

Utilization of lignocellulosic hydrolysates for photomixotrophic chemical production in Synechococcus elongatus PCC 7942

To meet the need for environmentally friendly commodity chemicals, feedstocks for biological chemical production must be diversified. Lignocellulosic biomass are an carbon source with the potential for effective use in a large scale and cost-effective production systems. Although the use of lignocellulosic biomass lysates for heterotrophic chemical production has been advancing, there are challenges to overcome. Here we aim to investigate the obligate photoautotroph cyanobacterium Synechococcus elongatus PCC 7942 as a chassis organism for lignocellulosic chemical production. When modified to import monosaccharides, this cyanobacterium is an excellent candidate for lysates-based chemical production as it grows well at high lysate concentrations and can fix CO2 to enhance carbon efficiency. This study is an important step forward in enabling the simultaneous use of two sugars as well as lignocellulosic lysate. Incremental genetic modifications enable catabolism of both sugars concurrently without experiencing carbon catabolite repression. Production of 2,3-butanediol is demonstrated to characterize chemical production from the sugars in lignocellulosic hydrolysates. The engineered strain achieves a titer of 13.5 g L−1 of 2,3-butanediol over 12 days under shake-flask conditions. This study can be used as a foundation for industrial scale production of commodity chemicals from a combination of sunlight, CO2, and lignocellulosic sugars.

Coking-Produced Aromatic Compounds in Urine of Exposed and Nonexposed Populations: Exposure Levels, Source Identification, and Model-Based Health Implications.

Coking contamination in China is complex and poses potential health risks to humans. In this study, we collected urine samples from coking plant workers, nearby residents, and control individuals to analyze 25 coking-produced aromatic compounds (ACs), including metabolites of polycyclic aromatic hydrocarbons (PAHs) and their derivatives, chlorophenols, and nitrophenols. The median concentration of total ACs in urine of workers was 102 μg·g-1 creatinine, significantly higher than that in the other two groups. Hydroxy-PAHs and hydroxy hetero-PAHs were the dominant ACs. Workers directly exposed from coking industrial processes, i.e., coking, coal preparation, and chemical production processes, showed higher concentrations of hydroxy-PAHs and hydroxy hetero-PAHs (excluding 5-hydroxyisoquinoline), while those from indirect exposure workshops had higher levels of other ACs, indicating different sources in the coking plant. The AC mixture in workers demonstrated positive effects on DNA damage and lipid peroxidation with 5-hydroxyisoquinoline and 3-hydroxycarbazole playing a significant role using a quantile g-computation model. Monte Carlo simulation revealed that coking contamination elevated the carcinogenic risk for exposed workers by 5-fold compared to controls with pyrene, pentachlorophenol, and carbazole contributing the most, and workers from coking process are at the highest risk. This study enhances understanding of coking-produced AC levels and provides valuable insights into coking contamination control.

Mesoporous PdO–loaded WO3 nanocrystals: A promising photocatalyst for highly efficient photoreduction of nitrobenzene to aniline under visible light

BackgroundNitrobenzene (NTB) conversion to aniline (AN) is a key technology for large-scale industrial chemical production and wastewater treatment. Accordingly, photocatalytic reduction of nitrobenzene has emerged as a green technology to produce aniline. MethodsThis study offers a simple nontoxic surfactant-assisted fabrication of mesoporous tungsten oxide (WO3) nanostructures accompanied by the incorporation of tiny contents (0.5‒2.0 wt%) of palladium oxide (PdO) nanoparticles through impregnation and calcination. Significant findingsPhysicochemical investigations of fabricated heterostructures revealed the formation of mesoporous surfaces and showed the implication of PdO loading on textural and optoelectronic characteristics of WO3. Only 2.0 wt% PdO on the WO3 surface caused a notable decline in the energy bandgap from 2.77 to 1.07 eV, confirming visible light-harvesting improvement. The prepared PdO–loaded WO3 was examined for NTB photoreduction to AN. The optimum content of 1.5 wt% PdO/WO3 (2.0 g L–1) exhibited a complete phototransformation of NTB to AN after only 40 min with excellent reusability and recyclability. The PdO loading significantly facilitated photoinduced charge carriers’ separation and mobility through the construction of Step (S)-scheme heterojunction. This work opens the door for developing semiconductor-based photocatalysis as a green process for effectively converting contaminated water into useful value-added chemicals.