Monday, September 15, 2025

Study reveals how nitrogen atmosphere enhances performance of iron-biochar catalysts in wastewater treatment

Biochar Editorial Office, Shenyang Agricultural University

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Atmosphere regulation: unraveling effective strategies for creating high-performance iron ore/biochar composite nanomaterials in ball milling processes

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Credit: Hui Zhang, Zi Cheng, Kai Hu, Boxiong Shen, Honghong Lyu & Jingchun Tang

A recent study published in Biochar demonstrates that the atmosphere used during ball milling plays a critical role in determining the effectiveness of iron-biochar composites for degrading organic pollutants in water. The research, conducted by a team from Hebei University of Technology and Nankai University, shows that composites prepared under a nitrogen atmosphere exhibit superior catalytic performance compared to those milled in air or vacuum.

Ball milling is a widely used technique for modifying materials to enhance their environmental applications. However, most studies have focused on optimizing mechanical parameters, while the influence of the milling atmosphere has remained underexplored. This study systematically investigates how different atmospheres—air, nitrogen, and vacuum—affect the properties and reactivity of siderite-biochar composites (BM-SD/BCs).

The team found that the composite milled under nitrogen (N/BM-SD/BC) achieved a phenol removal rate of 90.3% within 120 minutes when used to activate persulfate (PS), a common oxidant. This was significantly higher than composites milled in air (73.8%) or vacuum (81.3%). The nitrogen atmosphere helped preserve reduced iron species (Fe(II)), which are crucial for activating PS to generate sulfate and hydroxyl radicals that break down pollutants.

Characterization revealed that the nitrogen-milled composite had a smaller particle size, larger specific surface area (187.6 m² g⁻¹), and more uniform distribution of iron and functional groups. These properties enhanced electron transfer and provided more active sites for reaction.

The system also showed strong performance across a wide pH range, including conditions typical of real wastewater, highlighting its potential for practical use. Radical quenching experiments confirmed that hydroxyl radicals (·OH) and superoxide radicals (O₂·⁻) were the primary reactive species, contributing 50.7% and 25.3% to phenol degradation, respectively.

“This work underscores the importance of controlling the ball milling atmosphere to tailor material properties for environmental catalysis,” said Dr. Honghong Lyu, corresponding author of the study. “Using nitrogen during milling helps maintain high Fe(II) content and functional group integrity, leading to more efficient pollutant degradation.”

The study provides new insights into the design of high-performance catalysts for advanced oxidation processes and supports the application of ball-milled composites in real-world water treatment scenarios.

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Reference: Zhang, H., Cheng, Z., Hu, K. et al. Atmosphere regulation: unraveling effective strategies for creating high-performance iron ore/biochar composite nanomaterials in ball milling processes. Biochar 7, 82 (2025). https://doi.org/10.1007/s42773-025-00474-y

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Media Contact:
Wushuang Li
liwushuang@vip.126.com

About Biochar

Biochar is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.

Journal

Biochar

DOI

10.1007/s42773-025-00474-y

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Atmosphere regulation: unraveling effective strategies for creating high-performance iron ore/biochar composite nanomaterials in ball milling processes

DECOLONIZATION

Professorship to study ‘skeletons in the closet’

University of Otago

Historical anatomical skeletal collections held across Britain will be investigated by a University of Otago – Ōtākou Whakaihu Waka academic, thanks to a more than NZ$2 million professorship.

Professor Siân Halcrow, of the Department of Anatomy, is the first New Zealander to receive a British Academy Global Professorship, which will enable her to spend four years researching at England’s Durham University.

The Professorships, funded by the UK's Department for Science, Innovation and Technology, are an opportunity for established researchers to undertake high-risk, curiosity-driven research at a UK research institution.

Professor Halcrow was “stunned” to receive one.

“It felt like such a long shot applying, especially as there are only eight awarded per annum for the scheme with over 1,000 applicants from all over the world. It is extra special as it is the first time this has been awarded to someone from New Zealand,” she says.

She will spend the time researching the bioethics of the use, curation, and repatriation of anatomical skeletal collections – which are primarily used for education and research – held in British museums and universities.

“It is a sensitive and challenging area, and just how human remains have been acquired in the past is controversial, many of them are literally skeletons in the closet. Collections are largely made up of the marginalised in society – the poor and working class, women, children, the enslaved and those under colonial rule.

“Along with establishing who these remains were, and how they were acquired, I’ll be looking at how they have been used over time in terms of teaching, curation, display, education and outreach, and the policies, protocols and ethical considerations associated with that,” she says.

Professor Halcrow intends to develop the first socially informed practice and policy guidelines for anatomical skeletal collections, which would be relevant to Britain and globally.

“These would revolutionise how institutions handle human remains, leading to more respectful and equitable practices,” she says.

Professor Halcrow will start her professorship in October and will be based at Durham for four years. However, she will be travelling back to New Zealand regularly for continuing work on her Marsden project looking at this same topic from a New Zealand perspective.

Professor Halcrow has a long-standing research relationship with Durham, with both universities part of the Matariki Network. She has worked with Professor Rebecca Gowland, who is a collaborator on this project, previously, and been a recipient of a University of Durham Senior Research Fellowship.

Through a Fulbright Award in 2023, Professor Halcrow has also investigated the curation and use of anatomical human skeletal remains in universities and museums in the US.

She also recently studied the historical human skeletal collections held within Otago’s W.D. Trotter Anatomy Museum – the largest human anatomical collection in the Southern Hemisphere.

“The founding of the Medical School and museum has close ties with Britain, with the professors of anatomy being trained in Edinburgh and the Royal College of Surgeons of England.

“We found evidence of the commodification and dehumanising of bodies sold from India, along with others purchased from unknown sources overseas, or from marginalised local women.

“This made me want to extend investigations to Britain, to tackle the intersecting colonial legacies in skeletal acquisition and curation in Britain and its colonies.”

Phasor-FLIM visualizes and quantifies polluting nanoplastic particles in live organoids

Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS

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Figure | Principle of the phasor-FLIM barcoding approach and its application to studying the MNP interactions with small intestinal organoids. A, graphical representation of the approach. The polluting polymer is used for producing MNPs, labeled with the near-infrared dye, showing characteristic fluorescence lifetime. MNPs are exposed to the intestinal organoids (basal/apical-out…) with the polarity controlled by the live microscopy. Phasor-FLIM approach is used to analyze the uptake route, mechanism, physiological effect or quantifying the complex mixtures of the absorbed MNPs in the live organoid culture. B, confocal fluorescence images and corresponding phasor plots of organoids incubated with NPs (cyan), co-stained with Nile Red (yellow), demonstrate positive accumulation of only NP B and D, with the characteristic lifetimes confirmed by phasor-FLIM.
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Credit: Okkelman, I.A., Zhou, H., Borisov, S.M. et al.

Plastics pervade every aspect of the human life, being present in packaging and household goods, agricultural, food and medical products. Their resistance to (bio)degradation has resulted in the global accumulation of micro- and nanoplastics (MNPs) across diverse ecosystems, including soils, animals, aquatic environments, the atmosphere, food sources, and plants. Disturbingly, MNPs have already been detected in human blood, the brain, the gut, the reproductive system, and various other organs, raising pressing demand to understand their potential health effects. Recent studies with rodents and human cells already demonstrate the potential negative impact of MNPs on cell metabolism, oxidative stress and inflammation. However, it remains unclear whether these effects occur in human tissues or across diverse animal species within a physiologically relevant three-dimensional context. Therefore, to establish a fundamental understanding of MNP uptake, mechanisms and their effects on three-dimensional gastrointestinal tissue must be elucidated.

In a new paper published in Light: Science & Applications, a team of scientists, led by Professor Dmitriev from Tissue Engineering and Biomaterials Group, Ghent University (Ghent, Belgium), and co-workers, have developed a novel live imaging approach, addressing the dynamics of the MNP interaction with live intestinal tissue, within 3D and near-to-physiological setting: the team has designed ‘model’ near-infrared (NIR) emitting nanoplastic particles, which display characteristic differences in fluorescence lifetime (intrinsic characteristic for every luminescent molecule, reflecting its excited state duration), dependent on the type of the polymer material and the (micro)environment. The predicted and ‘pre-calibrated’ nanoplastic particles fluorescence lifetimes are highly amenable for phasor-FLIM ‘barcoding’ method, allowing for quantifying and separating different MNP types. Subsequently, the team applied this approach to probe MNP interactions with pig and mouse small intestinal organoid cultures, present in either basal-out or apical-out topology, to reveal the structure-activity relationships for some widely present polluting polymers. This methodology enables deeper understanding of the MNP interaction with tractable in vitro and potentially multi-organ-on-a-chip and in vivo models. The presented ‘lifetime barcoding’ feature allows for detecting different types of MNP and potentially their interactions with a non-plastic matter, e.g. ions, biomolecules, toxic chemicals or metals. After observing the positive and “MNP type”-specific accumulation, the team also demonstrated how the proposed imaging pipeline can be combined with the studies of the mitochondrial dynamics, polarization and expression of inflammatory cytokines. Collectively, the presented approach is expected to help studying post-internalization intracellular fate of the absorbed or endocytosed MNPs, across the broad range of physiologically relevant biological models, including organoids, animal tissues and beyond, bringing improved understanding of the biological effects of the MNPs to the human, animals, inter-species communities and potentially other members of the kingdom of life.

“We evaluated internalization of the nanoplastics into the apical-out and basal-out organoids and their concentration-dependent uptake. Strikingly, when compared with conventional intensity-based quantification, phasor FLIM-based event counting demonstrated significantly improved sensitivity and specificity. Importantly, we did not detect any pixel counts in the control ‘no NP’ control organoids (40 organoids analyzed in total in both experimental replicates R1 and R2) with the chosen analysis settings, which made a rare event count value more significant.”

“In addition, the presented phasor-FLIM ‘barcoding approach’ can discriminate between the different types of nanoplastics within same organoid. By setting the fingerprint zones for NP B (PMMA-MA) and NP D (PS-MA), we quantified the percentage of total cluster points in NP D, D/B and B lifetime zones, enabling accurate detection of MNP composition inside intestinal organoids when exposed to a complex mixture of MNPs.”

“Phasor-FLIM lifetime barcoding feature allows for multiplexed MNP detection and can be potentially applied to other fluorescent nanoparticles (e.g. ion-, biomolecule- or metal-related probes) to investigate their interaction with intestinal plasma membrane domain and their biological effect on gastrointestinal tissue across in vitro organoid, microphysiological on-a-chip platforms or in vivo live tissue models.” the scientists forecast.

DOI

10.1038/s41377-025-01949-0

Article Title

Visualizing the internalization and biological impact of nanoplastics in live intestinal organoids by Fluorescence Lifetime Imaging Microscopy (FLIM)

Reliability assessment method of high grade steel large diameter natural gas transmission pipelines

KeAi Communications Co., Ltd.