In a groundbreaking development that could reshape sustainable agriculture and environmental remediation, researchers at Hunan Agricultural University have unveiled a novel biochar-based catalytic system capable of not only degrading persistent pesticide residues in soils but also converting these harmful chemicals into a valuable nutrient form directly usable by plants. This innovative approach specifically targets clothianidin, a neonicotinoid pesticide notorious for its persistence and ecological risks, transforming it into ammonium nitrogen (NH4+-N)—a fundamental nutrient required for optimal plant growth.
Clothianidin’s widespread use has raised serious concerns due to its long-lasting presence in agricultural soils and eventual accumulation in food crops, posing threats to both ecological balance and human health. Traditional remediation methods typically focus on breaking down or removing such contaminants without recovering the embedded nutrients. However, the research team led by Dong He, Yujiao Wen, and their colleagues has transcended this limitation by designing and synthesizing an iron–sulfur modified biochar material (BC@Fe3S4) through a facile hydrothermal process, which acts as an advanced oxidation catalyst when combined with peroxymonosulfate (PMS).
At the core of this technology is the activation of advanced oxidation processes (AOPs) by BC@Fe3S4, which catalyze the generation of multiple reactive oxygen species (ROS) including hydroxyl radicals (·OH), singlet oxygen (1O2), and sulfate radicals (SO4·−). These potent oxidants orchestrate the efficient cleavage of the clothianidin molecules, converting the toxin into less harmful substances while releasing ammonium nitrogen as a byproduct. Unlike conventional degradation methods that result in inert or even toxic residues, this process integrates soil remediation with nutrient recycling—an elegant circular solution aligned with the principles of sustainable agriculture.
To evaluate the practical implications of their catalyst system, the team conducted controlled greenhouse experiments using lettuce grown in soils spiked with clothianidin. In untreated conditions, pesticide residues were detected in the plant tissues and growth was notably stunted. Conversely, application of BC@Fe3S4 combined with PMS completely eradicated pesticide residues in the harvested lettuce and promoted a near doubling of plant dry biomass relative to control groups. This remarkable fertilization effect underscores the technology’s dual functionality, simultaneously safeguarding food safety and enhancing crop yield.
Delving deeper into the chemical mechanistic pathways, the researchers employed spectroscopic and trapping experiments to quantify and confirm the involvement of multiple reactive species driving pesticide degradation. The complementary action of hydroxyl radicals and sulfate radicals ensured the comprehensive breakdown of the pesticide’s molecular structure, while singlet oxygen contributed to selective oxidation reactions that facilitated the conversion process. This synergy within the AOP framework is critical to maximizing degradation efficiency and nutrient recovery.
Safety assessments through toxicity modeling revealed that the degradation intermediates and final breakdown products exhibited significantly reduced toxicity profiles compared to the original pesticide compound. This is particularly critical given the potential accumulation and persistence of intermediate metabolites in natural environments. The conversion to ammonium nitrogen represents not only detoxification but also a direct pathway for nutrient reintegration into soil nutrient cycles, reducing dependency on synthetic nitrogen fertilizers.
The implications of this novel approach extend well beyond the laboratory scale. Neonicotinoid residues like clothianidin remain a persistent global challenge, frequently detected above regulatory thresholds in vegetables and other edible crops. The biochar-based catalytic system presents a cost-effective, scalable, and environmentally benign technology capable of transforming contaminated fields into fertile grounds for sustainable food production. By activating the intrinsic nitrogen content of pesticides, this strategy introduces a paradigm shift—remediation transforms from a purely subtractive process into a regenerative cycle.
Importantly, the research team acknowledges that while greenhouse results are promising, extensive long-term field trials are essential to validate the stability, environmental safety, and economic viability of their catalyst under real-world agricultural conditions. Factors such as soil heterogeneity, microbial community interactions, and the presence of diverse contaminants will influence the catalyst performance and nutrient bioavailability. Future studies will also investigate the applicability of this biochar-based catalyst for a broader spectrum of nitrogen-rich pesticides, potentially broadening its use across various cropping systems.
This discovery aligns with global efforts to reconcile agricultural productivity with environmental stewardship, addressing two intertwined challenges: persistent pesticide contamination and sustainable nutrient management. By offering a method to degrade harmful residues while simultaneously replenishing soil fertility, this technology could minimize the reliance on chemical fertilizers, reduce ecological risks, and improve crop safety—a holistic win–win for farmers and consumers alike.
Co-corresponding author Zhonghua Zhou highlighted the broader vision behind this work, asserting that integrating pollutant degradation with nutrient recovery represents a pivotal advancement in agrochemical management. Such innovations are crucial as the agricultural sector grapples with mounting pressure to reduce chemical inputs while sustaining or increasing food production to meet growing global demands.
Equally compelling is the multifunctionality of the iron–sulfur modified biochar catalyst. Its synthesis via a simple hydrothermal method ensures accessibility and potential for large-scale production. Moreover, the catalyst’s utilization of peroxymonosulfate, a powerful yet selective oxidant, enables tunable activation of AOPs tailored to varying soil conditions and contaminant loads. Together, these attributes promise a versatile tool with broad applicability across different environmental remediation challenges.
This study not only advances fundamental understanding of pesticide degradation kinetics and pathways but also demonstrates transformative potential for sustainable agriculture practices. By reimagining pesticides not purely as pollutants but as reservoirs of recyclable nutrients, the research encourages a circular economy approach within agroecosystems, optimizing resource use and minimizing ecological footprints.
In sum, the innovative biochar-based AOP catalyst system developed by Dong He, Yujiao Wen, and their team marks a significant stride in environmental chemistry and agronomy. It offers a compelling proof-of-concept for converting pesticide residues into ammonium nitrogen, improving crop growth, and addressing soil contamination simultaneously. This scientific breakthrough opens promising avenues for future developments aimed at integrating pollution control with nutrient cycling, supporting resilient and sustainable food systems worldwide.
Subject of Research: Not applicable
Article Title: Conversation of pesticide residues into ammonium nitrogen (NH4+-N) through AOPs and its fertilization effect on lettuce growth
News Publication Date: 27-Jun-2025
Web References:
Biochar Journal
DOI: 10.1007/s42773-025-00465-z
References:
He, D., Wen, Y., Wei, S. et al. Conversation of pesticide residues into ammonium nitrogen (NH4+-N) through AOPs and its fertilization effect on lettuce growth. Biochar 7, 88 (2025).
Image Credits:
Credit: Dong He, Yujiao Wen, Shangzhi Wei, Shikai Li, Lide Liu, Jinmeng Wu, Zhi Zhou, Nan Zhou, Hongmei Liu & Zhonghua Zhou
Keywords
Soil chemistry, Metabolism, Soil science, Environmental chemistry, Environmental sciences, Chemistry
Tags: advanced oxidation processes in agricultureagricultural biotechnology breakthroughsammonium nitrogen for plantsbiochar catalytic systemclothianidin degradationconverting pesticides to nutrientsecological risks of neonicotinoidsenvironmental soil healthpesticide residue remediationsoil contamination and healthsustainable agriculture innovations
