Salt-templated transformation of waste plastics into single-atom catalysts for environmental and energy applications.

Upcycling plastic waste into single-atom catalysts (SACs) not only offers a sustainable solution for plastic waste management but also yields valuable functional materials for catalytic applications. Here, we report a simple and scalable method to transform various types of plastics, including polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, and their mixtures, into a diversity of porous SACs with different coordination chemistry and their excellent applications in a variety of catalytic reactions. Lamellar transition metal chloride salts (Ni, Fe, Co, Mn, and Cu) are employed as a template and catalyst for confined carbonization of plastics into layered SACs.

Metal-Free Carbon Cocatalysis in Fenton Chemistry.

To address the challenges of low hydrogen peroxide utilization efficiency and excessive iron sludge accumulation in conventional Fenton processes, metal-free carbon cocatalysts harness their cost-effectiveness, ecofriendliness, and modifiable surface to propel green and enhanced Fenton chemistry. Their cocatalytic efficacy stems from structural features (pore architecture, hybridization state, and dimension) and surface properties (defect, heteroatom, functional group, graphitic structure, and site distribution), resulting in carbon cocatalysts playing multifaceted roles in assisting Fenton systems. This overview provides mechanistic insights into carbon cocatalyzed Fenton reactions, focusing on electron sources for iron reduction, and categorizes mechanisms into three approaches (electron donors, carbon-Fe(III) complexes, and electron mediators).

A templating approach with phase change to tailored coordination of single- and multiple-atom catalysts.

Single-atom catalysts (SACs) with featured active sites exhibit exceptional catalytic activity and selectivity in catalysis. However, their scalable synthesis and precise control of structure coordination for on-demand atomic configurations remain the bottlenecks in practical applications. In this work, a facile and scalable strategy is developed to achieve massive production of varying molecular-coordinated single- and multi metal-based SACs.

Upscaled wood@MoS/FeO bulk catalysts for sustainable catalytic water pollutant removal.

Advanced oxidation processes (AOPs) play a pivotal role in purifying contaminated water and securing drinking water safety. Transition metal-based materials are highly effective AOP catalysts, while their applications are limited by their poor stability in the oxidative environment. In this study, we developed a composite catalyst, molybdenum disulfide/ferric oxide (MoS/FeO), to evaluate its catalytic performance and explore its underlying mechanisms in peroxymonosulfate activation.

Microwave-mediated red mud/biochar activation of percarbonates: synergistic optimization of oxygen vacancies and dual hotspot effect.

Tailwater treatment from high-standard plastic-cleaning wastewater and red mud (RM) resource recycling pose major challenges. In this study, a heterogeneous microwave-responsive catalyst, RM/biochar (RM/BC), was successfully prepared to synergistically integrate magnetic and dielectric losses for activation of sodium percarbonate (SPC) to degrade the plastic additive diethyl phthalate (DEP). Characterization analyses revealed that under oxygen-limited conditions at 600 °C, poplar leaf powder was fully carbonized, while FeO in RM was reduced to FeO and further transformed into FeO, forming a composite dominated by amorphous carbon and FeO.

Defective multi-element coordinated single atom catalysts (Cu-NSCl) for high-performance water decontamination.

Carbon materials have been demonstrated to be green catalysts in advanced oxidation processes (AOPs) for removing a wide range of organic pollutants from water. This study presents an innovative approach to transforming waste tyres into defective multi-element coordinated copper single-atom catalysts (CuSA-Tyre) for AOPs. CuSA-Tyre demonstrates superior efficiency in activating various oxidants, in particular peroxydisulfate (PDS), to oxidize organic pollutants through a nonradical electron transfer pathway.

Functional group modulation of Fe-1,3,5-benzenetricarboxylic acid materials: Enhancing peroxymonosulfate activation while preserving synthetic simplicity.

This work aims to design peroxymonosulfate (PMS) catalytic materials that exhibit both high catalytic activity and ease of preparation. Fe-1,3,5-benzenetricarboxylic acid (Fe-BTC), known for its environmentally friendly and convenient synthesis, was selected as the template. A series of derived materials were developed under green and mild conditions using a functional group modulation strategy, in which one -COOH group in BTC was substituted with -NO, -NH, pyridine nitrogen, or -H.

Isotope Techniques in Chemical Wastewater Treatment: Opportunities and Uncertainties.

A comprehensive and in-depth analysis of reaction mechanisms is essential for advancing chemical water treatment technologies. However, due to the limitations of conventional experimental and analytical methods, the types of reactive species and their generation pathways are commonly debatable in many aqueous systems. As highly sensitive diagnostic tools, isotope techniques offer deeper insights with minimal interference from reaction conditions.

Enhanced oxidative degradation of 2,4-dichlorophenol by iron oxychloride supported on graphitic carbon nitride via peroxymonosulfate activation: Significant role of Fe(II)/Fe(III) conversion cycle.

The activation of peroxymonosulfate (PMS) by heterogeneous catalysts presents an exciting but challenging strategy for degrading persistent organic pollutants in water. Iron oxychloride (FeOCl) is considered a promising heterogeneous catalyst due to its unique oxygen bridge structure, which could render it more active by facilitating the iron valence transitions between Fe(II) and Fe(III). However, the limited Fe(II)/Fe(III) conversion cycle rate hinders its catalytic activity, leading to unsatisfactory PMS activations in practical applications.

Suitability evaluation of rural domestic sewage treatment processes in cold areas of Northeast China: Regional differences analysis and engineering application.

Rural domestic sewage (RDS) has been identified as one of the major factors hindering rural revitalization. The results of field research show that the cold areas of Northeast China have the characteristics such as scattered rural distribution and long duration of low temperature in winter, which makes it difficult to choose the most effective domestic sewage treatment processes. As a multi-objective decision-making issue based on specific scenarios, this study combines Analytic Hierarchy Process (AHP) with Fuzzy Comprehensive Evaluation (FCE) to establish a new suitability evaluation model for RDS in those areas.

The Nature of Molecular Hybridizations in Nanodiamonds for Boosted Fe(III)/Fe(II) Circulation.

Reducing agents have been frequently utilized as electron donors for Fe(II) generation to resolve the sluggish Fe(III) reduction in Fenton-like reactions, while their irreversible consumption necessitates a robust catalytic system that utilizes green electron donors such as HO. In this study, we used annealed nanodiamonds (NDs) as a collection of model catalysts with different sp/sp ratios to investigate the roles of the molecular structure in boosting the Fenton-like reactions. The annealed NDs acted as an electron mediator to transfer electrons from HO to surface-adsorbed Fe(III) for Fe(II) generation as well as an electron donor for direct Fe(III) reduction, driving Fe(II)-catalyzed HO decomposition to produce massive hydroxyl radicals, demonstrating potential in the real-water matrixes.

Overlooked Complexation and Competition Effects of Phenolic Contaminants in a Mn(II)/Nitrilotriacetic Acid/Peroxymonosulfate System: Inhibited Generation of Primary and Secondary High-Valent Manganese Species.

Organic contaminants with lower Hammett constants are typically more prone to being attacked by reactive oxygen species (ROS) in advanced oxidation processes (AOPs). However, the interactions of an organic contaminant with catalytic centers and participating ROS are complex and lack an in-depth understanding. In this work, we observed an abnormal phenomenon in AOPs that the degradation of electron-rich phenolics, such as 4-methoxyphenol, acetaminophen, and 4-presol, was unexpectedly slower than electron-deficient phenolics in a Mn(II)/nitrilotriacetic acid/peroxymonosulfate (Mn(II)/NTA/PMS) system.

Overlooked Impacts of Alcohols in Electro-HO and Fenton Chemistry.

Alcohols are promising fuels for direct alcohol fuel cells and are common scavengers to identify reactive oxygen species (ROS) in electro-Fenton (EF) systems. However, the side impacts of alcohols on oxygen reduction reactions and ROS generation are controversial due to the complex interactions between electrodes and alcohol-containing electrolytes. Herein, we employed synchrotron-Fourier-transform infrared spectroscopy and electron paramagnetic resonance technologies to directly observe the changes of chemical species and electrochemical properties on the electrode surface.

Atomic-Level Engineered Cobalt Catalysts for Fenton-Like Reactions: Synergy of Single Atom Metal Sites and Nonmetal-Bonded Functionalities.

Single atom catalysts (SACs) are atomic-level-engineered materials with high intrinsic activity. Catalytic centers of SACs are typically the transition metal (TM)-nonmetal coordination sites, while the functions of coexisting non-TM-bonded functionalities are usually overlooked in catalysis. Herein, the scalable preparation of carbon-supported cobalt-anchored SACs (CoCN) with controlled Co─N sites and free functional N species is reported.

Research Progress of Ozone/Peroxymonosulfate Advanced Oxidation Technology for Degrading Antibiotics in Drinking Water and Wastewater Effluent: A Review.

Nowadays, antibiotics are widely used, increasing the risk of contamination of the water body and further threatening human health. The traditional water treatment process is less efficient in degrading antibiotics, and the advanced oxidation process (AOPs) is cleaner and more efficient than the traditional biochemical degradation process. The combined ozone/peroxymonosulfate (PMS) advanced oxidation process (O/PMS) based on sulfate radical (SO) and hydroxyl radical (•OH) has developed rapidly in recent years.

Research Progress on the Degradation of Organic Pollutants in Water by Activated Persulfate Using Biochar-Loaded Nano Zero-Valent Iron.

Biochar (BC) is a new type of carbon material with a high specific surface area, porous structure, and good adsorption capacity, which can effectively adsorb and enrich organic pollutants. Meanwhile, nano zero-valent iron (nZVI) has excellent catalytic activity and can rapidly degrade organic pollutants through reduction and oxidation reactions. The combined utilization of BC and nZVI can not only give full play to their advantages in the adsorption and catalytic degradation of organic pollutants, but also help to reduce the agglomeration of nZVI, thus improving its efficiency in water treatment and providing strong technical support for water resources protection and environmental quality improvement.

Occurrence, Bioaccumulation, Metabolism and Ecotoxicity of Fluoroquinolones in the Aquatic Environment: A Review.

In recent years, there has been growing concern about antibiotic contamination in water bodies, particularly the widespread presence of fluoroquinolones (FQs), which pose a serious threat to ecosystems due to their extensive use and the phenomenon of "pseudo-persistence". This article provides a comprehensive review of the literature on FQs in water bodies, summarizing and analyzing contamination levels of FQs in global surface water over the past three years, as well as the bioaccumulation and metabolism patterns of FQs in aquatic organisms, their ecological toxicity, and the influencing factors. The results show that FQs contamination is widespread in surface water across the surveyed 32 countries, with ciprofloxacin and norfloxacin being the most heavy contaminants.

Effects of dissolved organic matter, pH and nutrient on ciprofloxacin bioaccumulation and toxicity in duckweed.

Water pollution induced by antibiotics has garnered considerable concern, necessitating urgent and effective removal methods. This study focused on exploring ciprofloxacin (CIP) removal by duckweed and assessing CIP bioaccumulation and toxic effects within duckweed under varying dissolved organic matter categories, pH levels, and nutrient (nitrogen (N) and phosphorus (P)) levels. The results revealed the proficient and rapid elimination of CIP from water by duckweed, resulting in 86.

Occurrence and Health Risk Assessment of Sulfonamide Antibiotics in Different Freshwater Fish in Northeast China.

This study aimed to investigate the levels of 12 sulfonamide antibiotics in freshwater fish species obtained from three cities in northeastern China (Harbin, Changchun, and Shenyang). The analysis was conducted using HPLC-MS/MS to accurately quantify the antibiotic concentrations in the fish samples. The results showed that the average levels of sulfonamide antibiotics in fish samples from Harbin, Changchun, and Shenyang were 1.

The Removal of Pollutants from Wastewater Using Magnetic Biochar: A Scientometric and Visualization Analysis.

In recent years, the use of magnetic biochar in wastewater treatment has shown significant effects and attracted scholars' attention. However, due to the relatively short research time and the lack of systematic summaries, it is difficult to provide a more in-depth analysis. This study utilizes RStudio and CiteSpace software to comprehensively analyze the research trends and progress of magnetic biochar in wastewater treatment.

Diversity characterization of bacteria and fungi in water, sediments and biofilms from Songhua River in Northeast China.

Water, sediments, and biofilms are the typical microbial carriers in natural water environments. However, comparative analysis of the distribution of bacterial and fungal communities in different carriers within the same habitat is relatively lacking. Therefore, this study employed 16 S and ITS rRNA gene sequencing to identify bacterial and fungal community structures in water, sediments, and biofilm.

Redox-Active Polymers as Robust Electron-Shuttle Co-Catalysts for Fast Fe/Fe Circulation and Green Fenton Oxidation.

Accelerating the rate-limiting Fe/Fe circulation in Fenton reactions through the addition of reducing agents (or co-catalysts) stands out as one of the most promising technologies for rapid water decontamination. However, conventional reducing agents such as hydroxylamine and metal sulfides are greatly restricted by three intractable challenges: (1) self-quenching effects, (2) heavy metal dissolution, and (3) irreversible capacity decline. To this end, we, for the first time, introduced redox-active polymers as electron shuttles to expedite the Fe/Fe cycle and promote HO activation.