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1.
Environ Geochem Health ; 46(7): 229, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849639

ABSTRACT

Pesticide micropollutants like 4-chlorophenol (4CP) and E. coli bacteria represent a substantial hazard, impacting both the environment and human health. This study delves into the effectiveness of Ag-doped TiO2 (Ag@TiO2) in removing both 4CP and E. coli. Ag@TiO2 has demonstrated remarkable effectiveness in removing 4CP under both solar and visible light conditions, earning degradation efficiencies of 91.3% and 72.8%, respectively. Additionally, it demonstrates outstanding photodegradation efficiency for 4CP (98.8%) at an initial concentration of 1 mg L-1. Moreover, Ag@TiO2 exhibited substantially higher removal performance for 4CP (81.6%) compared to TiO2 (27.6%) in wastewater. Analysis of the radicals present during the photodegradation process revealed that ·O2- primarily drives the decomposition of 4CP, with h+ and ·OH also playing significant roles in the oxidation reactions of the pollutant. Interestingly, even under dark conditions, Ag@TiO2 exhibited the capability to eliminate approximately 20% of E. coli, a percentage that increased to over 96% under solar light. In addition, the prospects for environmental and health impacts of utilizing Ag@TiO2 for pesticide micropollutant removal and bacteria were discussed.


Subject(s)
Chlorophenols , Escherichia coli , Pesticides , Silver , Sunlight , Titanium , Water Pollutants, Chemical , Titanium/chemistry , Pesticides/chemistry , Silver/chemistry , Chlorophenols/chemistry , Water Pollutants, Chemical/chemistry , Photolysis , Wastewater/chemistry
2.
Environ Res ; 233: 116483, 2023 09 15.
Article in English | MEDLINE | ID: mdl-37352951

ABSTRACT

Caffeine (CaF), a widely consumed compound, has been associated with various harmful effects on human health, including metabolic, cardiovascular disease, and reproductive disorders. Moreover, it poses a signifincant threat to organisms and aquatic ecosystems, leading to water pollution concerns. Therefore, the removal of CaF from wastewater is crucial for mitigating water pollution and minimizing its detrimental impacts on both humans and the environment. In this study, a solar-driven Cu-doped graphitic carbon nitride (Cu/CN) photocatalyst was synthesized and evaluated for its effectiveness in oxidizing CaF in wastewater. The Cu/CN photocatalyst, with a low band gap energy of 2.58eV, exhibited superior performance in degrading CaF compared to pure graphitic carbon nitride (CN). Under solar light irradiation, CuCN achieved a remarkable CaF degradation efficiency of 98.7% CaF, surpassing CN's efficiency of 74.5% by 24.2%. The synthesized Cu/CN photocatalyst demonstrated excellent removal capability, achieving a removal rate of over 88% for CaF in wastewater. Moreover, the reusability test showed that Cu/CN could be successfully reused up to five cycles maintaining a high removal efficiency of 74% for CaF in the fifth cycle. Additionally, the study elucidated the oxidation mechanism of CaF using solar-driven Cu/CN photocatalyst and highlighted the environmental implications of the process.


Subject(s)
Caffeine , Wastewater , Humans , Ecosystem , Sunlight , Catalysis
3.
Environ Res ; 231(Pt 3): 116246, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37245581

ABSTRACT

The presence of pharmaceutical pollutants in water has emerged as a significant public health concern due to their potential adverse impacts, including the development of antibiotic resistance. Consequently, advanced oxidation processes based on photocatalysis have garnered considerable attention for treating pharmaceutical contaminants in wastewater. In this study, graphitic carbon nitride (g-CN), a metal-free photocatalyst, was synthesized by the polymerization of melamine and assessed as a potential candidate for the photodegradation of acetaminophen (AP) and carbamazepine (CZ) in wastewater. Under alkaline conditions, g-CN demonstrated high removal efficiencies of 98.6% and 89.5% for AP and CZ, respectively. The relationships between degradation efficiency and catalyst dosage, initial pharmaceutical concentration, and photodegradation kinetics were investigated. Increasing the catalyst dose facilitated the removal of antibiotic contaminants, with an optimum catalyst dose of 0.1 g, achieving a photodegradation efficiency of 90.2% and 82.7% for AP and CZ, respectively. The synthesized photocatalyst removed over 98% of AP (1 mg/L) within 120 min, with a rate constant of 0.0321 min-1, 2.14 times faster than that of CZ. Quenching experiments revealed that g-CN was active under solar light and generated highly reactive oxidants such as hydroxyl (•OH) and superoxide (•O2-). The reuse test confirmed the good stability of g-CN for treating pharmaceuticals during three repeated cycles. Finally, the photodegradation mechanism and environmental impacts were discussed. This study presents a promising approach for treating and mitigating pharmaceutical contaminants in wastewater.


Subject(s)
Environmental Pollutants , Graphite , Wastewater , Metals , Pharmaceutical Preparations , Catalysis
4.
Chemosphere ; 324: 138372, 2023 May.
Article in English | MEDLINE | ID: mdl-36905998

ABSTRACT

Titanium oxide-based nanomaterials (TiOBNs) have been widely utilized as potential photocatalysts for various applications such as water remediation, oxidation, carbon dioxide reduction, antibacterial, food packing, etc. The benefits from TiOBNs for each application above have been determined as producing the quality of treated water, hydrogen gas as green energy, and valuable fuels. It also acts as potential material protecting foods (inactivation of bacteria and removal of ethylene) and increases shelf life for food storage. This review focuses on recent applications, challenges and future perspectives of TiOBNs to inhibit pollutants and bacteria. Firstly, the application of TiOBNs to treat emerging organic contaminants in wastewater was investigated. In particular, the photodegradation of antibiotics pollutants and ethylene using TiOBNs are described. Secondly, applying TiOBNs for antibacterial to reduce disease, disinfection, and food spoiling has been discussed. Thirdly, the photocatalytic mechanisms of TiOBNs to mitigate organic pollutants and antibacterial were determined. Finally, the challenges for different applications and future perspectives have been outlined.


Subject(s)
Environmental Pollutants , Nanostructures , Catalysis , Anti-Bacterial Agents/pharmacology , Titanium , Bacteria , Water
5.
Molecules ; 27(16)2022 Aug 09.
Article in English | MEDLINE | ID: mdl-36014291

ABSTRACT

Endophytic fungi are recognized for their many potential applications in agriculture, such as supporting cropland expansion and increasing the yield and resistance of plants by creating antibiotics that inhibit the growth of pathogenic microorganisms. In addition, they can produce enzymes that break down hard-to-solubilize substances within soil, dissolve phosphates, fix nitrogen, reduce metals, and produce hormones that promote plant growth (auxin, cytokinin, and gibberellins) to keep crops healthy. In this report, three strains of endophytic fungi, namely, N1, N2, and N3, were isolated from the roots of Stevia rebaudiana (Bert.) Hemsl., Polyscias fruticosa, and Angelica dahurica in some localities in Vietnam. Through a screening process, it was found that they can produce high levels of indole acetic acid (IAA), resolve phosphates, and resist disease, and they were selected to as an alternative to chemical fertilizers to make probiotics in order to increase medicinal plant yields. The results show that the three strains of fungi have the ability to degrade phosphate to 341.90, 1498.46, and 390.79 ppm; the content of IAA produced in the culture medium reached 49.00, 52.35, and 33.34 ppm. Based on some morphological characteristics and an internal transcribed spacer gene sequence analysis of the fungal strains, N1, N2, and N3 were named Penicillium simplicissimum CN7, Talaromyces flavus BC1, and Trichoderma konilangbra DL3, respectively, which have the ability to inhibit the growth of pathogenic fungal strains, such as fungus C. gloeosporioides (CD1), fungus F. oxysporum, fungus L. theobromae N13, and N. dimidiatum. They grow significantly over a period of 5 to 6 days.


Subject(s)
Plants, Medicinal , Rhizosphere , Endophytes/metabolism , Fungi/metabolism , Phosphates/metabolism , Vietnam
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