Reduction Of Toxicity Research Articles

Exploring Sustainable Remediation Options: The Mycodegradation of Halogenated Nitroaromatic Compounds by Caldariomyces fumago

Chlorinated and fluorinated nitrophenols (HNCs) are widely used in agriculture and industry, with a global market valued at USD $25 billion, one which is expected to grow by 5% by 2030. However, these compounds pose significant environmental risks; they are classified as toxic by the International Agency for Research on Cancer (IARC). Existing treatment methods include advanced oxidation, adsorption, and bioremediation, though to date, there has been only limited research on fungal remediation of these halogenated pollutants. This study aims to explore a sustainable approach by using fungi’s potential to degrade HNCs in minimal media. Ten fungi were selected through literature screening; Caldariomyces fumago and Curvularia sp. were highly effective, degrading over 50% of 2-chloro-4-nitrophenol (2C4NP) and 80% of 5-fluoro-2-nitrophenol (5F2NP) within 24 and 48 h, respectively. Additionally, five strains showed degradation potential for fluorinated compounds. Further studies revealed C. fumago could degrade up to 1 mM of chlorinated compounds and 12 mM of fluorinated compounds, far exceeding any known environmental concentrations of HNCs; importantly, ecotoxicology tests demonstrated reductions in toxicity of 77% and 85%, respectively. This work highlights fungi’s underexplored ability to degrade toxic HNCs, offering a sustainable mycoremediation strategy and positioning mycology as a critical tool for future environmental remediation efforts.

The Electrooxidation of Synthetic Bipyridyl Herbicide Wastewaters with Boron-Doped Diamond Electrodes: A Technical and Economic Study to Boost Their Application for Pollution Prevention in the Agricultural Sector

Boron-doped diamond electrodes (BDDEs) offer a highly efficient pathway to mineralize recalcitrant compounds due to their reduced energy requirements, fewer chemical inputs, and mechanical stability. In this work, the electrochemical degradation of paraquat (PQ) and diquat (DQ) was studied using an undivided cell (Condiacell®-type) at circumneutral pH, and under galvanostatic control. The roles of applied current density, volumetric flow rate, and herbicide concentration were systematically studied through a central composite design (CCD) using a closed-flow reaction setup. Under the best operating conditions (i.e., for PQ: 1.6 mA/cm2, 80 mL/min, and 70 mL/min, and 70 mg/L; and for DQ: 1.5 mA/cm2, 80 mL/min, and 73 mg/L), a spectrophotometric analysis evidenced that the herbicides were satisfactorily removed (ca. 100%) while mineralization degrees were above 90%. Furthermore, the produced effluents yielded significant increases in seed germination and root length, which suggest a reduction in toxicity. Energy consumptions of 0.13 and 0.18 kWh/g of TOC are reported with the electrochemical cells for the PQ and DQ treatments, respectively. The PQ and DQ treatments by electrooxidation are estimated to emit nearly 2.7 and 38.9 kg CO2/m3 of water treated, with a cost around USD 250/m3. Carbon emissions could be greatly decreased for PQ (0.28 kg CO2/m3) and DQ (0.40 kg CO2/m3) if electricity were generated from renewable resources. Although this study suggests that the use of BDDE can be considered as a green alternative for agrochemical removal due to lower carbon emissions, the environmental profile of the process is determined by the degree of renewability of the electrical grid of each country or region.

Computer prediction of acute toxicity of thioderivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenol

This study presents the computational prediction of acute toxicity for new derivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenols and their alkylated analogues. The aim of the work was to evaluate the impact of structural changes, particularly alkylation and chain length extension, on the toxicity levels of new derivatives of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenols and their alkylated analogues. Materials and methods. QSAR methodologies were used to predict toxicity, allowing the evaluation of toxicological properties based on molecular descriptors. Toxicity modeling was performed using computer software, enabling the estimation of toxicity without the need for in vivo experimental studies. Results. The results showed, that alkylation of 3,5-bis(5-mercapto-4-R-4H-1,2,4-triazol-3-yl)phenol derivatives does not lead to a significant toxicity reduction. Moreover, an increase in toxicity was observed with the prolongation of the carbon chain in the synthesized compounds. It was also found, that acid derivatives, particularly 2,2’-(((5-hydroxy-1,3-phenylene)bis(4-R-4H-1,2,4-triazol-5,3-diyl))bis(sulfanyl))diacetate acids and 3,3’-((((5-hydroxy-1,3-phenylene)bis(4-R-4H-1,2,4-triazol-5,3-diyl))bis(sulfanyl))bis(methylene))dibenzoyl acids, exhibit toxicity ranging from 521.9 mg/kg to 2232.2 mg/kg, corresponding to toxicity class IV (low toxicity) on the OECD scale. It was found, that molecular structure and hydrophobic properties play a crucial role in determining compound toxicity. This study helps to establish a structure-toxicity relationship and to optimize compound structures for reduced toxicity. Conclusions. These results provide a foundation for further development of potential drug candidates with predicted toxicological properties.

Photocatalytic Degradation of Antiviral Drugs Chloroquine Phosphate and Lamivudine by Bi2O3–TiO2/PAC under a Xe Lamp: Insights into Reactive Oxygen Species’ Action and Toxicity Reduction

Photocatalytic Degradation of Antiviral Drugs Chloroquine Phosphate and Lamivudine by Bi₂O₃–TiO₂/PAC under a Xe Lamp: Insights into Reactive Oxygen Species’ Action and Toxicity Reduction

Oxygen vacancies-enriched spent lithium-ion battery cathode materials loaded catalytic membrane for effective peracetic acid activation and organic pollutants degradation

Advanced oxidation processes combined with membrane filtration technique offer a promising approach for pollution mitigation and catalyst recovery. Herein, a waste ternary lithium-ion battery cathode material of LiNixCoyMnzO2 (LNCM) loaded polytetrafluoroethylene (PTFE) membrane was synthesized for peracetic acid (PAA) activation (LNCM-PTFE/PAA) and 2,4,6-trichlorophenol (TCP) degradation. Such a novel membrane, with a catalyst loading of 10 mg (0.796 mg/cm2) of LNCM achieved 96.4 % removal of TCP (2 mg/L) within 20 min in neutral pH. The redox cycles of surface metals (such as Co3+/Co2+, Ni3+/Ni2+, and Mn4+/Mn3+/Mn2+) in spent LNCM efficiently enhance charge transfer and mediated PAA activation. And intrinsic oxygen vacancies in LNCM facilitated PAA adsorption and its cleavage. The resulting carbon-centered radicals (R-C•, CH3C(O)OO•) and 1O2 are identified as the primary reactive species that collaboratively participate in TCP degradation. Quantitative structure-activity relationship analysis demonstrated a substantial reduction in product toxicity. The successful practical application of the LNCM-PTFE/PAA membrane was exemplified by treating chlorophenol industrial wastewater. This study presents a new LNCM-PTFE/PAA catalytic membrane for high-efficiency water treatment and a novel perspective for green utilization of waste LNCM.

A hybrid system based on the combination of adsorption, electrocoagulation, and wetland treatment for the effective remediation of industrial wastewater from underground coal gasification (UCG)

The study verified the effectiveness of treating post-process underground coal gasification (UCG) wastewater, containing high loads of inorganic and organic pollutants, using constructed wetlands (CW) enhanced by hybrid adsorption and electrocoagulation (EC) techniques. Four different system configurations were tested: wetland, EC/wetland, adsorbent/wetland, and EC/adsorbent/wetland. Each experiment lasted 60 days. The feed and effluents from each treatment step were analysed for their basic physicochemical parameters such as metals and trace elements, phenols, sulphides, cyanides, total organic carbon (TOC), chemical oxygen demand (COD), biological oxygen demand (BOD), benzene, toluene, ethylene, xylene (BTEX), and polyaromatic hydrocarbons (PAHs).Systems with electrocoagulation proved to be effective in the case of metal removal. The best results were obtained for Fe, Ni, Sb and As (up to 96%, 98%, 94% and 82% respectively). The systems were ineffective in removing Mn. All tested systems showed the greatest effectiveness in the treatment of wastewater from phenols, BTEX and CN (almost 100% removal). CWs without preliminary electrocoagulation showed practically 100% effectiveness in removing BTEX after 14 days of treatment. Electrocoagulation was particularly effective in reduction of large quantity of PAH compounds (from 1228 μg/l to below 0.050 μg/l). Effective toxicity reduction from V class to II class after 60 days in comparison with meeting the requirements contained in the Best Available Techniques (BAT) document, showed that all tested systems were favorable in terms of UCG wastewater treatment. A significant decrease in toxicity was observed in just 14 days (around 90% reduction of toxicity measured in TU values for systems without adsorbent and around 75% for systems with adsorbent). The wastewater were still toxic due to the formation of degradation intermediates of organic compounds (BTEX, PAHs, phenol compounds), despite a significant decrease in the concentration of contaminants, therefore toxicity assessment should be one of the evaluation criteria for industrial wastewater treatment.

A highly-efficient peroxymonosulfate activator using a sewage sludge derived biochar supported cobalt oxide: Mechanism and characteristics

The application of biochar derived from sewage sludge (BS) in Fenton-like reactions for contaminant removal has attracted considerable attention. Herein, a BS-supported Co3O4 (BS-Co3O4) catalyst was synthesized using a simple two-step hydrothermal-calcination process to achieve highly efficient activation of peroxymonosulfate (PMS). The introduction of biochar effectively inhibited the aggregation of Co3O4 and reduced cobalt leaching. Compared to Co3O4, the mesoporous BS-Co3O4 exhibited an 8-fold increase in specific surface area (SSA) to 111.92 m2∙g−1, and a 46 %-66.4 % reduction in crystal plane size. The interaction between biochar and cobalt oxide resulted in several notable enhancements in the BS-Co3O4 composite. Specifically, there was an increase in sp2 carbon content, a 42.69 % rise in capacitance, and a 79.99 % reduction in charge transfer resistance. These improvements contributed to enhanced PMS activation performance. The BS-Co3O4 also contained a higher content of Co(II), sp2 carbon, and oxygen vacancies (OV). Co(II) played a crucial role in the redox reaction, accelerating the formation of SO4•− and 1O2 during the PMS activation process. Additionally, OV acted as electron capture centers, further promoting the generation of 1O2. Evidence from reactive species investigations and electron paramagnetic resonance (EPR) tests indicated that SO4•− and 1O2 were the main reactive radicals for eliminating tetracycline (TC). Based on the identification of TC intermediates, two potential degradation pathways were proposed, and a reduction in intermediate toxicity was observed. Experiments involving interference and repetition demonstrated that the BS-Co3O4 catalyst was stable and reusable. This work provides a solution with low metal leaching, high recycling performance, and safety for antibiotic wastewater treatment.

Highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon as efficient persulfate activation catalyst

The selective removal of Fe particles from carbonized Fe-MOFs presents an intriguing strategy for developing efficient peroxydisulfate (PDS) activators. It is commonly accepted that their outstanding performance is largely attributed to the high specific surface area/pore volume. However, our investigation into the structure–function relationship of these materials has revealed new insights. In this study, a highly dispersed single-atom Fe and Fe3O4 clusters anchored hierarchical-pore carbon (CM88-H) was obtained via post-acid treatment of carbonized MIL-88B (CM88). Various characterizations were comparatively conducted to highlight the beneficial effects of iron dissolution. The CM88-H/PDS system achieved a notable BPA degradation efficiency, with a reaction rate of 0.323 min−1, which is 3.94 times higher than that of the CM88/PDS system. DFT calculations indicate that the Fe3O4 clusters optimize the charge distribution around single-atom Fe, promoting favorable PDS adsorption and facilitating a higher oxidation state of CM88-H. As a result, BPA can be completely degraded within 10 min with 0.1 g/L CM88-H and 0.05 g/L PDS via both radical and non-radical pathways. The CM88-H/PDS/BPA system performs effectively under various conditions, with a general reduction in toxicity. Furthermore, the CM88-H/PDS system shows broad oxidation activity towards BPA substitutes and pollutants with high ionization potential (IP). Notably, the CM88-H sponge-based fixed-bed catalytic reactor demonstrated satisfactory BPA degradation, highlighting the promising application of CM88-H in water purification. This study provides a sustainable solution for water treatment and accelerates the practical application of powdered nanocatalysts to improve water quality.

Integrated respiratory toxicity of municipal wastewater to human bronchial epithelial cells and 3D bronchospheres

Respiratory symptoms have been reported in wastewater treatment workers and residents living close to sewage treatment plant. However, toxicological research about the respiratory hazards of municipal wastewater is scarce. The present study aims to gain insight into the comprehensive respiratory hazards induced by the contaminant mixtures in municipal wastewater. The integrated respiratory hazards of effluents from four secondary wastewater treatment plants (SWTPs), a tertiary wastewater treatment plant (TTP), and a constructed wetland (CW) were evaluated using normal human bronchial epithelial cells (NHBE) bioassay, and toxicity reduction efficiency of various treatment techniques was analyzed. Effluents caused cytotoxicity, oxidative damage, inflammation response with the increased levels of IL-6 and CXCL8, and impaired barrier integrity with decreased expressions of ZO-1 and occludin in NHBE. Further, the effluents inhibited the development of 3D bronchospheres, increased irregular surface and cell debris, and suppressed the formation of luminal structures. TTP E effluent significantly increased the expression of MUC5AC in bronchospheres. The integrated biomarker response (IBR) of the influent was removed by 40.2% at SWTPs, 18.2% at TTP, and 36.6% at CW, respectively. The IBR of the final effluents from SWTPs, TTP, and CW were 7.2, 7.7, and 7.7, respectively. Significant correlation with toxicity biomarkers was frequently observed for stearyl alcohol, o-cresol, phenanthrene, butylated hydroxytoluene, and dimethyl phthalate. The present study provided human relevant evidence concerning the adverse respiratory effects associated with discharge. The necessity for deep water treatment, performance optimization, and the potential means were suggested for improving water quality and protecting respiratory health.

Understanding abscisic acid-mediated stress signaling to affect rice development under stress

IntroductionRice is a vital staple food for many countries, and its yield is known to be significantly affected by various abiotic stresses, which are expected to intensify with climate change, posing a threat to global food security. Abscisic acid (ABA), a crucial plant growth regulator, plays a crucial role in plant responses to these abiotic stresses. It influences several processes, such as seed dormancy, leaf gas exchange, reactive oxygen species (ROS) scavenging, ion toxicity reduction, and root elongation, all of which contribute to enhancing plant survival under stress.MethodsThis article reviews recent research on ABA-mediated gene responses and expressions involved in rice plant architecture and its response to abiotic stress.Results and discussionAbscisic acid responses were primarily driven by changes in gene expression. Expression analyses of the gene related to ABA biosynthesis or catabolism indicated several changes in plant architecture, such as changes in leaf angle, delayed flowering, and modifications in growth regulators. Additionally, tolerance-related mechanisms, such as increased ROS scavenging, reduced membrane leakage, and vacuolar compartmentation of toxic radicals, were activated under single or multiple stress conditions. While these adaptations may improve plant survival and yield sustainability under stress, they may not necessarily enhance yield potential in environments affected by drought, salinity, or heat stress. ABA expression was also associated with improved pollen viability, grain-filling potential, and seed setting under abiotic stresses such as heat, which could enhance seed yield in such challenging environments.

Azacitidine in combination with shortened venetoclax treatment cycles in patients with acute myeloid leukemia.

The combination of venetoclax with hypomethylating agents is currently the standard of care for elderly patients with acute myeloid leukemia (AML) ineligible for intensive chemotherapy. Despite its favorable efficacy, clinical use is often associated with post-remission cytopenia, frequently necessitating treatment delays and dose modifications. This study aims to evaluate the efficacy and safety of shortened venetoclax treatment durations. A multicenter analysis was conducted involving 20 adult AML patients receiving venetoclax (7 or 14 days with 9 and 11 patients, respectively) combined with 5-azacitidine (5-7 days) between 2021 and 2024. The cohort included patients from four German academic centers all treated in first line. Outcome measures included bone marrow response, transfusion dependence, overall survival (OS) and progression-free survival (PFS). Median age was 73.5 years, with 70% of patients having secondary AML. Adverse molecular risk was observed in 75% of patients. The overall response rate (ORR) was 100%, with a composite complete remission rate of 78%. No significant differences in response rates were observed between the 7-day and 14-day venetoclax regimens. Median OS for the cohort was 15 months. Infection-related complications were observed in 55% of patients, with severe sepsis in 20% of cases. In this cohort, shortened venetoclax regimens demonstrated efficacy comparable to standard treatment protocols, with a potential reduction in hematologic toxicity. These findings support the individualization of treatment regimens to optimize clinical outcomes while potentially minimizing adverse effects.

Processing-induced reduction in dianthrones content and toxicity of Polygonum multiflorum: Insights from ultra-high performance liquid chromatography triple quadrupole mass spectrometry analysis and toxicological assessment.

Polygonum multiflorum-induced liver injury (PM-DILI) has significantly hindered its clinical application and development. This study investigates the variation in content and toxicity of dianthrones, the toxic components of P. multiflorum, during different processing cycles. We employed the ultra-high-performance liquid chromatography triple quadrupole mass spectrometry method to quantify six dianthrones in raw P. multiflorum and formulations processed with a method called nine cycles of steaming and sunning. Additionally, toxicity assessments were conducted using human normal liver cell line L02 and zebrafish embryos. Results indicate a gradual reduction in dianthrones content with increasing processing cycles. Processed formulations exhibited significantly reduced cytotoxicity in L02 cells and hepatotoxicity in zebrafish embryos. Our findings elucidate the relationship between processing cycles and P. multiflorum toxicity, providing theoretical support for its safe use.

Assessment of sweet whey fortified with Bifidobacteria and selenium on reduction of pesticide liver toxicity in albino rats

Deltamethrin (DLM) represents one of the most commonly used pesticides. It passes through milk, vegetables, and fruits to humans or through animals (veterinary drugs and feeding on contaminated forage) to milk; it can escape from skin to blood and be secreted in breast milk in lactating women. It is believed to have neurotoxic, nephrotoxic, and hepatotoxic properties. To investigate deltamethrin-induced hepatotoxicity, 64 rats were divided into eight groups. The control group did not receive any treatment. The groups were as follows: D 30 mg DLM/kg body weight (BW) dissolved in corn oil; B 1 mL whey (1010 cfu/mL of Bifidobacterium longum ATCC 15707); S 1 mL whey (0.5 ppm selenium); BS 1 mL whey (1010 cfu/mL of B. longum ATCC 15707 + 0.5 ppm selenium); BD 1 mL whey (1010 cfu/mL of B. longum ATCC 15707 + DLM); SD 1 mL whey (0.5 ppm selenium) + DLM; and BSD 1 mL whey (1010 cfu/mL of B. longum ATCC 15707) + 0.5 ppm selenium + DLM. Results revealed that the manipulation of Bifidobacteria with selenium triggered a significant improvement in AST (U/mL), ALT (U/mL), GSH (mg/g), TNF-α (pg/mL), NF-κB (ng/mL), and BCL2 (ng/mL) from 166.7 ± 6.42, 30.67 ± 0.55, 0.252 ± 0.005, 17.18 ± 0.42, 1.14 ± 0.10, and 1.77 ± 0.06 versus 334.9 ± 4.7, 72.83 ± 2.49, 0.108 ± 0.005, 33.57 ± 0.59, 2.58 ± 0.05, and 1.04 ± 0.04, respectively, compared to DLM group. As well as reduction in histopathological necrosis, congestion, and degradation. Whey beverages fortified with B. longum and selenium implicated a reduction in oxidative stress and histopathological degradation that accomplished DLM toxicity. The utilization of whey (a byproduct of cheese making) is considered a recycling process that supports eco-friendly practices and sustainability, thus encouraging its use as a protective tool in animal feed or manipulation by humans, especially workers in pesticide plants.

The Role of Oral Nutritional Supplements in Head and Neck Cancer Patients Undergoing Chemoradiotherapy.

This study aimed to assess the impact of oral nutritional supplements (ONS) on nutritional intake, body weight, and body composition in head and neck cancer (HNC) patients undergoing chemoradiotherapy. The study evaluated whether ONS could prevent treatment-related nutritional deterioration. This prospective observational pilot study included 30 HNC patients randomized into two groups: ONS (n = 15) and No ONS (n = 15). All participants underwent chemoradiotherapy, with the ONS group receiving 200 mL of a high-calorie, high-protein supplement twice daily. Nutritional status, including body weight, BMI, fat mass, fat-free mass, and bone mass, was assessed at three time points: baseline, mid-treatment, and end of treatment. Data were analyzed using the Mann-Whitney U test, with a p-value of ≤0.05 considered statistically significant. At baseline, there were no significant differences between the two groups in body weight, BMI, or body composition. By the end of radiotherapy, the No ONS group showed significant reductions in body weight (p < 0.001), BMI (p < 0.001), fat mass (p < 0.001), and fat-free mass (p < 0.001), while the ONS group maintained more stable nutritional parameters. Acute radiotherapy toxicities, including nausea, dysphagia, and oral mucositis, were not significantly different between the two groups. ONS effectively mitigates weight loss and preserves body composition in HNC patients undergoing chemoradiotherapy. While no significant reduction in radiation-induced toxicities was observed, the nutritional benefits of ONS support its use in preventing malnutrition in this patient population. Larger studies are needed to further validate these findings.

Iodine-125 low-dose rate prostate brachytherapy.

Robotic-assisted laparoscopic radical prostatectomy and intensity-modulated radiation therapy are the most common radical treatments for localized prostate cancer, and brachytherapy (BT) also plays a role in this field. Iodine-125 (I-125) low-dose rate (LDR) prostate BT is an established treatment. However, it remains controversial. Specifically, there are a variety of issues, such as indications for combined treatment with external beam radiotherapy and androgen deprivation therapy, prostate-specific antigen follow-up, the significance of postimplant biopsy, the usefulness of salvage BT and focal therapy, reduction of toxicities, and bladder cancer after BT. In this review, we summarize the recent developments in I-125 LDR BT.

ESSAI DE TRAITEMENT BIOLOGIQUE DES HUILES LUBRIFIANTES USAGÉES RÉCUPÉRÉES DANS DES GARAGES DE KINSHASA À L’AIDE DES URINES HUMAINES ET KAOLIN EN RÉPUBLIQUE DÉMOCRATIQUE DU CONGO

In the various car garages of Kinshasa (in the Democratic Republic of Congo), the lack of consideration of environmental standards is the basis of the voluntary and/or accidental discharges of used oils directly into the environment without any prior treatment. These used hydrocarbons are pollutants that can cause major environmental problems due to their toxicity. The aim of this study is to treat used lubricating oils from car garages biologically in order to reduce their toxic potential. To this end, an aerobic biological treatment system was set up by mixing 4L of used oils with IL of urine, 2Kg of active Kaolin and 20L of water. The reduction in the toxicity of hydrocarbons was assessed through acute toxicity tests on the species Gambusia Affinis and microbiological analyses before and after biological treatment of these oils. The results obtained on the toxicity before treatment of these oils revealed that the LC50 was around ±3 ml/g of used oils to say that the pollutant is very toxic. After biological treatment, the LC50 rise to around ±66.7 ml/g for the treated oils, which represents a significant reduction in toxicity and ranks these treated oils in the order of less toxic effluents. The microbiological analyses of the used oils before their treatment did not show any bacteria; on the other hand, the analyses after treatment made it possible to highlight the presence of bacterial colonies whose identification revealed the following bacteria: Citrobacter, Enterobacter, Klebsiella and Pseudomonas, which are mostly lipolytic. This study thus allowed to treat used oils thanks to microorganisms and the intrinsic properties of urine and Kaolin.

Photocatalytic Fenton-like degradation of Acid Green 25 by novel aluminum nanoferrites with persulfate: Optimization by response surface methodology

Magnetic nanomaterials are gaining increasing attention for their catalytic properties and ease of recovery, making them promising candidates for the degradation of various organic pollutants. In this study, AlFe2O4 nanoparticles were employed for the first time in photocatalytic wastewater treatment. The study focused on removing Acid Green 25 anthraquinone dye through persulfate activation under UV-Visible light. AlFe2O4 nanoparticles were synthesized via sol-gel auto-combustion method and characterized by various techniques (XRD, SEM, EDX, VSM, Raman and FTIR). Moreover, statistical analysis of the experimental data confirmed the strong performance of the RSM model in accurately representing the photocatalytic process. Under optimal conditions including persulfate and catalyst concentrations of 0.3 g/L and 0.83 g/L respectively, a solution pH of 3 and 45 minutes of contact time, a 96 % dye removal rate was achieved. The remaining persulfate concentration was 60 % and fully depleted within 90 minutes, indicating efficient activation by AlFe2O4 photocatalyst. The activation process effectively suppressed electron-hole recombination, enhancing the overall efficiency. Scavenger experiments further identified surface-bound radicals and photogenerated holes as the main reactive species. A degradation mechanism for AG25 dye via a photocatalytic Fenton-like process was proposed, highlighting dual synergistic catalysis in the dye degradation. Ecotoxicity assessments using Vibrio fischeri bioassay revealed a significant reduction in toxicity after treatment with AlFe2O4/PS/UV-Vis system. The stability of AlFe2O4 was demonstrated over five degradation cycles. The findings open new perspectives for the use of AlFe2O4 in advanced wastewater treatment technologies, positioning it as a promising material for the degradation of persistent pollutants.

Efficacy of two different forms of selenium towards reduction of arsenic toxicity and accumulation in Cicer arietinum L.

Arsenic migration from soil to crop plants and subsequently human consumption of contaminated foodstuffs is a serious threat for society. In the present study, two oxidation states of selenium [Se(0) and Se(VI)] were used to check their efficacy towards amelioration of arsenic toxicity in chickpeas (Cicer arietinum L.). Three different concentrations (1, 5, and 10 mg/L) of both oxidation states of selenium were applied separately and in combination against a fixed dose (10 mg/L) of arsenic [(As(V)] treatment on chickpea seedlings. Further, seed germination and seedling growth attributes, oxidative stress, and antioxidant defense under different treatments were analyzed. The changes in anatomical structures and arsenic accumulation in different parts of seedlings were also studied. Results revealed that increased generation of oxidative stress affected physiobiochemical parameters of seedlings and diminished plant growth and deformation in vascular bundles under arsenic stress. However, the combined application of Se with As showed overall improvement in seedling growth, reduced oxidative stress, and organized vascular bundles of chickpea seedlings as compared to arsenic stress alone. The arsenic uptake and accumulation in chickpea seedlings were also reduced upon supplementation of Se. The highest reduction of arsenic accumulation by 42 and 56 % in roots, while 47 and 58 % in shoots were recorded by the application of 10 mg/L of Se(0) and Se (VI) under As stress, respectively. Overall, Se(VI) showed much better performance towards the minimization of arsenic-induced phytotoxicity and arsenic accumulation as compared to Se(0). Therefore, this study explored the efficacy of different forms of selenium towards the mitigation of arsenic toxicity in plants.

Balanced adsorption and oxidation in a porous P, N-doped carbon prepared by melt-salt-mediated strategy for enhanced fenton-like reaction

The activation of persulfate oxidation processes using carbon-based catalysts is attractive for eliminating persistent aromatic organic pollutants in wastewater treatment. Herein, N and P co-doped carbonaceous (NPC) catalysts with an ultrahigh surface area were synthesized using a melt-salt-mediated strategy, employing Zeolitic Imidazolate Framework-8 as a self-sacrificing template. The NPC(1:1) carbon, prepared under optimized conditions, exhibited the highest surface area of 2001.5 m2/g, characterized by the highest number of defects and a high dispersion of N (1.89 %) and P (0.30 %) atoms on the carbon. This carbon catalyst exhibited a high capacity for adsorption and potential for activating persulfates in the removal of p-Nitrophenol (p-NP). Experimental data indicate a balance between adsorption and oxidation in the NPC(1:1)/PDS/p-NP system, with the highest catalytic removal rate achieved through moderate pre-adsorption of p-NP. Evidence from quenching, electron paramagnetic resonance (EPR), and amperometric i-t experiments suggests that the NPC(1:1)/PDS system primarily degrades p-NP through an electron transfer pathway. Defects in carbon and graphitic N were identified as catalytic sites. These defects resulted in an electron-deficient state, which leads to the activation of PDS and graphitic N was more reactive than both pyridinic and pyrrolic N in the adsorption of PDS molecules. Additionally, P-containing groups such as C-P-O, C-O-P, and C3-P were pinpointed as active sites on the carbons through DFT calculations. The intermediates during p-NP degradation were identified, and possible degradation pathways were proposed. A toxicity analysis indicated a significant reduction in overall toxicity following the oxidation treatment. This study provides innovative insights into the balance between adsorption and catalytic activity in porous carbon-activated persulfate oxidation reactions, thereby aiding in the development of enhanced oxidation catalysts for environmental remediation.

Unraveling the residual sludge-mediated waste transformation and physiological regulation mechanism of Tetradesmus obliquus

The accumulation of residual sludge as process waste from water treatment engineering needs to be addressed urgently. Tetradesmus obliquus is an important algal species in the field of wastewater treatment. In this study, T. obliquus was cultured in different sludge extract to determine its ability to utilize wastes from the liquid phase and convert them into biomass, and to analyze the response of the microalgae to toxic stress using proteomics. The results showed that the sludge extract medium was superior to the BG11 medium in accumulating biomass, with dry weights, proteins and polysaccharides at least 1.09, 1.12 and 1.28 times higher than those of BG11 medium. In toxic group, T. obliquus reduced TOC from an initial 426.8±20.0 mg/L to 180.4±8.5 mg/L with a simultaneous 48.4 % reduction in toxicity. Toxic sludge extract produced greater damage to the photosystem of T. obliquus compared to the blank, significantly inhibiting the expression of two photosystem II core proteins, A0A383VSL5 (0.290 down) and A0A383V2Z3 (0.308 down), on day 5. However, these impairments were reversible, and at day 20, the expression of A0A383VSL5 was not inhibited, the inhibitory effect of A0A383V2Z3 (0.575 down) was attenuated. These results fill a gap on the treatment of various types of residual sludge by T. obliquus and provide promising strategies for microalgae treatment of residual sludge, whether non-toxic or toxic.