Key Takeaways & Executive Findings
- •• • Optimal EDTMPS degradation of 99.48% was achieved at 50 °C, 300 mL·min−1, 7.0 V, pH 10, and 0.05 mol·L−1 Na2SO4, demonstrating near-complete removal under moderate conditions. • • The presence of chloride ions enhanced degradation rates compared to chloride-free systems, though the improvement was marginal; EPR confirmed the generation of chlorine radicals in addition to hydroxyl and sulfate radicals. • • In a coexisting system with benzotriazole (BTA), degradation efficiencies for EDTMPS and BTA were comparable under conditions of 0.05 mol·L−1 Na2SO4, 40 °C, 390 mL·min−1, 7.0 V, and pH 8, indicating non-selective oxidation. • • The degradation mechanism involves both direct anodic oxidation and indirect oxidation via reactive radicals, with indirect oxidation playing a dominant role, leading to complete mineralization into CO2, PO4^3−, and N2.
Abstract
Ethylene diamine tetra (methylene phosphonic acid) sodium (EDTMPS), an organic phosphonate scale and corrosion inhibitor, is widely used in industrial recirculating cooling water systems. Its efficient degradation in blowdown water is critical for water reuse. This study employed a plate-frame electrochemical advanced oxidation (EAOP) system with a boron-doped diamond (BDD) anode to degrade EDTMPS. The effects of operating conditions (temperature, voltage, liquid flow rate) and water quality parameters (pH, electrolyte concentration, chloride ion concentration) were systematically investigated. Optimal degradation efficiency of 99.48% was achieved at 50 °C, 300 mL·min−1, 7.0 V, pH 10, and 0.05 mol·L−1 Na2SO4. Electron paramagnetic resonance (EPR) characterization of chloride-containing systems indicated that reactive species included hydroxyl radicals, sulfate radicals, and possibly chlorine radicals. In a coexisting system with benzotriazole (BTA), EAOPs degraded EDTMPS and BTA with comparable efficiencies. The results demonstrate that BDD-based EAOPs is effective for removing organic phosphonates from low-chloride, low-hardness cooling water, offering a promising approach for blowdown water treatment and reuse.
1. Introduction
Industrial recirculating cooling water systems operate at high concentration cycles, demanding high stability to prevent corrosion and scaling. Organic phosphonate inhibitors like EDTMPS are widely used due to their excellent scale and corrosion inhibition, but their strong C–P bonds and stable phosphonic groups render them resistant to natural degradation. In blowdown water, EDTMPS not only hampers water reuse but also contributes to eutrophication if discharged. Conventional degradation methods—photolysis, chemical oxidation, and biodegradation—suffer from slow kinetics, low efficiency, and potential toxic byproducts, creating a critical bottleneck for sustainable water management.
Electrochemical advanced oxidation processes (EAOPs) offer a promising alternative, generating strong oxidants such as hydroxyl and sulfate radicals in situ. This study employs a boron-doped diamond (BDD) anode in a plate-frame reactor to degrade EDTMPS, systematically optimizing operational and water quality parameters. The work specifically addresses the challenge of treating low-chloride, low-hardness cooling water, where conventional methods falter. By identifying optimal conditions and elucidating the radical mechanisms, this research provides a viable pathway for efficient EDTMPS removal, enabling safe discharge or reuse of blowdown water.
Loading authentic research manuscript (Pages 1–5)...
WANG Anshan, ZHANG Yulin, ZHANG Jie, LI Lehuan, ZHANG Yuling (2026). Degradation Efficiency of EDTMPS by BDD Anode Electrochemical Advanced Oxidation System. Environmental Chemistry. https://doi.org/10.7524/j.issn.0254-6108.2025041804
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What are the optimal operating conditions for maximum EDTMPS degradation, and how sensitive is the process to variations in these parameters?
The optimal conditions were 50 °C, 300 mL·min−1 flow rate, 7.0 V, pH 10, and 0.05 mol·L−1 Na2SO4, achieving 99.48% degradation. The process is sensitive: deviations in temperature, voltage, or pH can reduce efficiency, as these parameters directly influence radical generation and mass transfer.
How does the presence of chloride ions affect the degradation mechanism and efficiency?
Chloride ions slightly enhanced degradation rates compared to chloride-free systems. EPR analysis revealed the formation of chlorine radicals in addition to hydroxyl and sulfate radicals, which may contribute to oxidation. However, the improvement was marginal, suggesting that chloride radicals play a secondary role under the tested conditions.
What is the degradation mechanism of EDTMPS in this BDD-based EAOP system?
EDTMPS degradation occurs via both direct anodic oxidation and indirect oxidation by reactive radicals. Indirect oxidation, primarily by hydroxyl and sulfate radicals, is dominant, leading to complete mineralization into CO2, PO4^3−, and N2. Direct electron transfer at the anode surface is a minor pathway.
Can this process effectively treat coexisting pollutants like benzotriazole (BTA) in cooling water?
Yes, under conditions of 0.05 mol·L−1 Na2SO4, 40 °C, 390 mL·min−1, 7.0 V, and pH 8, EDTMPS and BTA were degraded with comparable efficiencies, indicating non-selective oxidation. This suggests the process can handle multi-contaminant streams, though the degradation rates were lower than the optimal single-solute case.
What are the practical implications for scaling up this technology to industrial cooling water systems?
The BDD anode demonstrated high efficiency (99.48%) under moderate conditions (50 °C, 7 V), suggesting energy and cost feasibility. However, scale-up must consider electrode fouling, mass transfer limitations, and the impact of real water matrices. The study used synthetic low-chloride, low-hardness water; pilot tests with actual blowdown water are necessary to validate performance and economic viability.
Related Chinese Research & Cross-Citations
Exploring the Potential Molecular Mechanisms of Eight Environmental Pollutants in Lung Adenocarcinoma through Network Toxicology, Machine Learning, and Multi-Omics Analysis
Epidemiological studies have established a significant association between exposure to environmental pollutants (EP) and the risk of lung adenocarcinoma (LUAD). This study integrates network toxicology and multi-omics analysis to elucidate the EP-LUAD molecular regulatory network and identify key regulatory genes, thereby revealing novel mechanisms of environmental carcinogenesis. Transcriptomic data from GEO and TCGA databases yielded 4,971 and 4,488 disease-related targets, respectively. Integration of toxicology databases (TargetNet, Swiss Target Prediction, CTD, SEA) identified 24,860 potential targets for eight common pollutants (SO2, NO, CO, NO2, O3, benzene, toluene, and polycyclic aromatic hydrocarbons). Intersection of these datasets produced 1,536 EP-LUAD common target genes. Protein-protein interaction network analysis identified 247 core targets. Machine learning selected five key genes: AGER, CAV1, CD44, CEP55, and GNB3, which demonstrated robust diagnostic and prognostic efficacy. Their expression correlated with immune cell infiltration, including CD4+ memory T cells and macrophages. Single-cell RNA sequencing revealed epithelial cell-specific expression patterns. Molecular docking confirmed stable pollutant-target binding, with PAH showing highest affinity for CD44 (binding energy −9.32 kcal·mol−1) and GNB3 (−8.32 kcal·mol−1). These findings establish AGER, CAV1, CD44, CEP55, and GNB3 as core molecular mediators of pollution-related LUAD. The high-affinity binding of PAH to CD44 and GNB3 underscores its carcinogenic potential. This study constructs a multi-level regulatory network for EP-LUAD, revealing underlying molecular mechanisms and providing novel potential targets and theoretical basis for early warning and intervention.
Effects of Different Functionalized Nanoplastics on the Transformation of Extracellular Antibiotic Resistance Genes in Aquatic Environments
The rapid dissemination of antibiotic resistance genes (ARGs) in aquatic environments poses serious threats to public health and environmental safety under the 'One Health' framework. Nanoplastics (NPs), as co-occurring pollutants, can exacerbate ARG risks by promoting horizontal gene transfer (HGT), yet the influence of different functional groups on extracellular ARG (eARG) transformation remains unclear. This study investigated the effects of carboxy-modified polystyrene NPs (PS-COOH) and amino-functionalized polystyrene NPs (PS-NH2) compared to unmodified polystyrene NPs (PS) on the transformation of the extracellular resistance plasmid IE-V1955 (carrying an ampicillin resistance gene) into Escherichia coli DH5α. Results showed that PS-COOH exposure promoted plasmid transformation similarly to PS, with effects increasing over 0.1–20 mg·L−1. Low concentrations (0.1–0.5 mg·L−1) of PS-NH2 also enhanced transformation, with stronger effects than PS-COOH at equal doses, whereas high concentrations (1–20 mg·L−1) inhibited it. Mechanistically, PS-COOH (0.1–20 mg·L−1) and low PS-NH2 induced intracellular reactive oxygen species (ROS), increased cell membrane permeability, elevated the protein-to-polysaccharide ratio in extracellular polymeric substances (EPS), and promoted biofilm formation, thereby facilitating transformation. High PS-NH2 concentrations caused excessive ROS leading to cell lysis and formed aggregates with plasmids larger than membrane pores, blocking uptake. These findings provide a theoretical basis for assessing the combined environmental health risks of NPs and ARGs.
Cardiovascular Toxicity Induced by Micro/Nano-Plastics and Its Mechanisms
Micro/nano-plastics (MNPs) are emerging contaminants widely detected in human circulatory systems, including blood, heart, and vascular endothelium, raising concerns about cardiovascular health risks. This systematic review analyzed 61 peer-reviewed studies (2008–2024) to elucidate the cardiotoxic effects and molecular mechanisms of MNPs. Evidence indicates that MNPs exposure elevates risks of atherosclerosis, thrombosis, and arrhythmias through oxidative stress, inflammatory cascades, endothelial dysfunction, and metabolic dysregulation. Notably, co-exposure with persistent organic pollutants (POPs) or heavy metals may produce synergistic or antagonistic effects. Current research relies predominantly on animal and cell models, with critical gaps in low-dose, long-term exposure data and epidemiological evidence. Future studies should optimize experimental designs, integrate metabolomics and epigenetics, and explore transgenerational effects and combined toxicity mechanisms to inform pollution control policies and mitigate cardiovascular risks.
Body Burden of Polybrominated Diphenyl Ethers and Joint Effects on Thyroid Function in a Physical Examination Population in Shenzhen
This study characterized the body burden of polybrominated diphenyl ethers (PBDEs) in a physical examination population in Shenzhen and evaluated its impact on thyroid function. Serum samples from 368 residents were analyzed for eight PBDE congeners using atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS). The median concentration of ∑8PBDEs was 10.2 ng·g⁻¹ lipid weight (lw), ranging from 0.13 to 2089.4 ng·g⁻¹ lw, with BDE-209 predominating (59.7% of total). Multiple linear regression revealed that a 1.7-fold increase in serum BDE-153 was associated with a 0.4% increase in free triiodothyronine (FT3) (P<0.05), while a 1.7-fold increase in BDE-183 was associated with a 0.9% decrease in total triiodothyronine (T3) and a 0.7% decrease in FT3 (P<0.05). Bayesian kernel machine regression (BKMR) indicated a negative correlation between mixed PBDE exposure and thyroid-stimulating hormone (TSH) at high exposure levels. Weighted quantile sum (WQS) regression showed that mixed exposure was associated with decreased T3 levels and T3/FT3 ratio, with BDE-153 and BDE-183 as the primary contributors. These findings suggest that PBDE exposure may adversely affect thyroid function and disrupt thyroid hormone homeostasis, with BDE-183 and BDE-153 playing key roles. This study provides a scientific basis for PBDE health risk assessment and thyroid protection.
Mechanisms of Natural Organic Matter in Regulating Microplastic Aggregation and Transport in Soil-Groundwater Systems: A Review
Microplastics (MPs) are persistent emerging contaminants ubiquitously distributed in soil-groundwater environments, where their aggregation and transport critically govern pollutant fate and ecological risks. Natural organic matter (NOM), a complex assemblage of organic compounds, interacts with MPs and porous media via hydrogen bonding, π-π interactions, hydrophobic effects, and electrostatic binding, thereby modulating MP surface properties and environmental behavior. This review systematically synthesizes the mechanisms by which NOM influences MP aggregation and transport, with emphasis on the distinct roles of humic substances, proteins, and extracellular polymeric substances (EPS), and their synergistic modulation with solution chemistry (pH, ionic strength, ion type). Additionally, NOM accelerates MP aging and alters surface characteristics, consequently impacting transport capacity. Current research limitations are identified, and future directions are proposed to inform MP pollution risk assessment and management strategies. Key findings indicate that NOM generally enhances MP stability and mobility at low ionic strengths, while high ionic strengths may induce aggregation depending on NOM type and ion valence. Humic substances predominantly increase electrostatic repulsion, whereas proteins and EPS can bridge particles, promoting aggregation. Aging processes, accelerated by NOM photochemical activity, increase surface oxygen functionality and hydrophilicity, further altering transport. The review underscores the need for systematic studies under environmentally relevant conditions to predict MP fate accurately.
Neurotoxicity of Carboxyl-Modified Polystyrene Microplastics on Zebrafish at Early Developmental Stage
Carboxyl-modified polystyrene microplastics (PS-COOH) are negatively charged particles formed by surface oxidation and functional group modification of polystyrene microplastics (PS), widely used in biomedical and analytical chemistry. However, studies on their neurotoxic effects on aquatic organisms are scarce. This study employed zebrafish (Danio rerio) as a model organism, exposing embryos to environmentally relevant concentrations (0.1, 1, 10, 100 μg·L−1) of PS and PS-COOH. Neurotoxic effects were assessed by measuring tail coiling frequency at 24 hpf and swimming velocity under alternating light/dark cycles at 120 hpf. Results demonstrated that both PS and PS-COOH induced neurotoxicity, with PS-COOH significantly reducing tail coiling frequency and average swimming speed compared to PS (P<0.05). Exposure to 10 μg·L−1 PS-COOH disrupted neurotransmitter homeostasis, altering levels of acetylcholine (ACh), serotonin (5-HT), and γ-aminobutyric acid (GABA). Transgenic zebrafish Tg(huc:EGFP) fluorescence assays revealed that PS-COOH (0.1–100 μg·L−1) caused damage to central neurons. These findings indicate that PS-COOH exposure impairs cholinergic, serotonergic, and GABAergic neurotransmission, induces neuronal damage, and exerts neurotoxic effects on zebrafish larvae. This study provides a theoretical basis for assessing the ecological and health risks of modified microplastics.