Chenyang Li

This study reports the successful preparation of a highly active NiCo2O4/biochar composite catalyst (CNBC) and systematically investigates its performance in peroxymonosulfate (PMS)-activated degradation of 4-chlorophenol (4-CP). The biochar carbonized at 600 °C exhibits a defect-rich, partially graphitized structure effectively inhibits NiCo2O4 aggregation and promotes interfacial electron transfer, thereby significantly enhancing catalytic activity. At pH 6.7, with 0.3 g L−1 of CNBC and 0.7 mM PMS, the catalyst achieved complete 4-CP degradation within 60 min, a mineralization efficiency of 67.3%. The reaction tolerated coexisting substances well and remained stable after repeated use. Mechanism studies showed that the reaction mainly followed a non-radical route. Singlet oxygen and direct electron movement through a short-lived CNBC-PMS* activated state played key roles. Surface groups such as C=O and -OH, together with adsorbed oxygen, acted as the main reaction centers. In addition, the reversible change between Co and Ni oxidation states helped sustain the catalytic activity. Liquid chromatography–mass spectrometry analysis and toxicity assessments indicated that the nine detected intermediates posed significantly lower ecological risks. Overall, the CNBC/PMS system exhibited excellent degradation efficiency, structural stability, and environmental compatibility. These findings provide both a material basis and theoretical support for the green oxidative remediation of chlorinated aromatic pollutants.

With the rapid development of the livestock farming industry, the treatment of livestock farming wastewater has become increasingly important. The microbial-algal biofilm method has gained widespread attention for cattle wastewater treatment owing to its non-toxic nature, resistance to shock loading, and high treatment efficiency. In this study, three types of substrates—polyurethane sponge, ceramic material, and moving bed biofilm reactor media—were evaluated. The formation of biofilms was assessed through variations in chlorophyll content, microscopic observations, and measurements of biofilm dry weight and attachment rate. Biofilm characterization on the different substrates was conducted via Fourier transform infrared spectroscopy, confocal laser scanning microscopy, and scanning electron microscopy. The results demonstrated that polyurethane sponge was the most effective substrate. Furthermore, a single-factor experiment was conducted to optimize the cultivation conditions for the microbial-algal biofilms and identify the optimal parameters based on the ability of the biofilm to remove COD, TN, TP, and NH₄⁺-N. The optimal conditions were as follows: an illumination intensity of 8000 lux, red light, a temperature of 20 °C, a pH of 7, and an aeration intensity of 8 L/min. Under these conditions, the pollutant removal rates were exceptionally high: ~73.4% for COD, 51.8% for TP, 57.0% for TN, and 75.1% for NH₄⁺-N.

In this paper, Au and Cu nanoparticles were successfully loaded onto porous g-C₃N₄ material through a hydrothermal synthesis method. By adjusting the proportion of Cu, Au-5%Cu/C₃N₄, Au-10%Cu/C₃N₄, and Au-15%Cu/C₃N₄, catalysts were prepared and used for the catalytic reduction of CO₂ to methanol. Characterization analysis using high-resolution XPS spectra showed that with an increase in the doping amount of Cu, the electron cloud density on the Cu surface initially increased and then decreased. Electrons from Au atoms transferred to Cu atoms, leading to the accumulation of a more negative charge on the Cu surface, promoting the adsorption of partially positively charged C in CO₂, which is more beneficial for catalyzing CO₂. Among them, Au-10%Cu/C₃N₄ exhibited good reducibility and strong basic sites, as demonstrated by H₂-TPR and CO₂-TPD, with the conversion rates for CO₂, methanol yield, and methanol selectivity being 11.58%, 41.29 g·kg⁻¹·h⁻¹ (0.39 μmol·g⁻¹s⁻¹), and 59.77%, respectively.

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. Furthermore, contamination levels are generally higher in developing and developed countries. It has been observed that compound types, species, and environmental factors influence the bioaccumulation, metabolism, and toxicity of FQs in aquatic organisms. FQs tend to accumulate more in organisms with higher lipid content, and toxicity experiments have shown that FQs exhibit the highest toxicity to bacteria and the weakest toxicity to mollusk. This article summarizes and analyzes the current research status and shortcomings of FQs, providing guidance and theoretical support for future research directions.

The ocean is the largest reservoir on Earth. With the scarcity of water resources, the destruction of the benign cycle of the marine ecosystem would seriously impact people’s quality of life and health. Oyster reefs, the world’s most endangered marine ecosystems, have been recognized as a global issue due to their numerous essential ecological functions and provision of various ecosystem services. As a result, interest in oyster reef research has been steadily increasing worldwide in recent decades. The goal of this study is to assess the knowledge structure, development trends, research hotspots, and frontier predictions of the global oyster reef research field. Based on 1051 articles selected from the Web of Science Core Collection from 1981 to 2022, this paper conducted a visual analysis of oyster reef ecosystems conservation, restoration, and management. Specifically, it examined research output characteristics, research cooperation networks, highly cited papers and core journals, and keywords. Results indicate a steady rise in research interest in oyster reefs over the past 40 years, with notable acceleration after 2014. Authoritative experts and high-impact organizations were also identified. This paper outlines habitat conservation and restoration, ecosystem services, and the impacts of climate change as the primary research hotspots and frontiers. This paper provides valuable guidance for scholars and regulators concerned about oyster reef conservation to conduct research on oyster reefs.

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 1.83 ng/g ww, 0.98 ng/g ww, and 1.60 ng/g ww, respectively. Sulfamethoxazole displayed the highest levels and detection rates in all three cities, whereas sulphapyridine exhibited the lowest concentrations in all the fish samples. The levels of sulfonamide antibiotic residues in the different fish species varied widely among the cities, and the highest level of antibiotic residues was found in the muscle of carnivorous fish. The results from a health risk evaluation on the consumption of these fish indicated that the risk from long-term antibiotic exposure to local residents from the intake of the sampled fish was small and not sufficient to pose a significant health risk to consumers.

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. The analysis of bibliometrics is performed on 551 relevant papers retrieved from the Web of Science, spanning the period between 2011 and 2022. The most influential countries, institutions, journals, disciplinary distribution, and top 10 authors and papers in this field have been identified. The latest dataset has been used for keyword clustering and burst analysis. The results indicated that: (1) Bin Gao is the most influential author in this field, and high-level journals such as Bioresource Technology are more inclined to publish articles in the field of magnetic biochar. (2) Research in this field has predominantly focused on the removal of heavy metals and organic compounds. Keyword burst analysis shows a shift in research direction towards the removal of complex organic pollutants recently. (3) For the future development of magnetic biochar, an environment-friendly approach, economic viability, and joint technology are the directions that need more exploration. Finally, this paper provides a summary of the various adsorption mechanisms of magnetic biochar and several common modification methods, aiming to assist scholars in their research endeavors.