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Rex M C, Debroy A, Mukherjee A. The impact of nTiO 2 and GO (graphene oxide), and their combinations, on freshwater Chlorella sp.: a comparative study in lake water and BG-11 media. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024; 26:1281-1294. [PMID: 38780043 DOI: 10.1039/d4em00041b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Titanium dioxide nanoparticles (nTiO2) and graphene oxide (GO) are extensively used nanomaterials in various products and applications. Freshwater ecosystems are a crucial sink for these pollutants, posing severe threats to aquatic organisms. Although multiple studies have investigated the pristine toxicity of nTiO2 and GO in freshwater organisms, the combined toxicity of these materials remains unexplored. Interaction media is a crucial factor in evaluating toxicity nanomaterial toxicity towards algae. In this study, we have investigated the comparative effect of sterilized and filtered freshwater and BG-11 medium on the pristine and combined toxicity of nTiO2 and GO on freshwater algae Chlorella sp. Results indicated that the combination of nTiO2 and GO showed more toxicity when compared to their respective pristine forms. This could be due to the additive effect exhibited by nTiO2 and GO on Chlorella sp. The enhanced growth inhibition for the combined toxicity was in the order of 1 mg L-1 nTiO2 + 1 mg L-1 GO > 1 mg L-1 nTiO2 + 0.1 mg L-1 GO > 0.1 mg L-1 nTiO2 + 1 mg L-1 GO > 0.1 mg L-1 nTiO2 + 0.1 mg L-1 GO. All test groups that interacted in BG-11 media exhibited less toxicity when compared to corresponding groups in the lake water medium. This could be attributed to the cushioning effect of BG-11 medium, providing supplementary nutrition to the algal cells. This signifies that the environmentally relevant conditions could be more detrimental than the laboratory conditions. This study elucidates valuable insights into the potential detrimental effects associated with the combination of nTiO2 and GO on freshwater algae. Furthermore, we have evaluated the growth inhibition, oxidative stress, and photosynthetic activity of Chlorella sp. in both environmentally relevant interaction medium and well-defined culture medium.
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Affiliation(s)
- Camil Rex M
- Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
| | - Abhrajit Debroy
- Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
| | - Amitava Mukherjee
- Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, Tamil Nadu, 632014, India.
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Arteaga-Castrejón AA, Agarwal V, Khandual S. Microalgae as a potential natural source for the green synthesis of nanoparticles. Chem Commun (Camb) 2024; 60:3874-3890. [PMID: 38529840 DOI: 10.1039/d3cc05767d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
The increasing global population is driving the development of alternative sources of food and energy, as well as better or new alternatives for health and environmental care, which represent key challenges in the field of biotechnology. Microalgae represent a very important source material to produce several high-value-added bioproducts. Due to the rapid changes in the modern world, there is a need to build new materials for use, including those in the nanometer size, although these developments may be chronological but often do not occur at a time. In the last few years, a new frontier has opened up at the interface of biotechnology and nanotechnology. This new frontier could help microalgae-based nanomaterials to possess new functions and abilities. Processes for the green synthesis of nanomaterials are being investigated, and the availability of biological resources such as microalgae is continuously being examined. The present review provides a concise overview of the recent advances in the synthesis, characterization, and applications of nanoparticles formed using a wide range of microalgae-based biosynthesis processes. Highlighting their innovative and sustainable potential in current research, our study contributes towards the in-depth understanding and provides latest updates on the alternatives offered by microalgae in the synthesis of nanomaterials.
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Affiliation(s)
- Ariana A Arteaga-Castrejón
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C, Unidad de Biotecnología Industrial, Camino al Arenero #1227, Col. El Bajío Arenal, 45019 Zapopan, Jalisco, Mexico.
| | - Vivechana Agarwal
- Centro de Investigación en Ingeniería y Ciencias Aplicadas, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Morelos, 62209, Mexico.
| | - Sanghamitra Khandual
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C, Unidad de Biotecnología Industrial, Camino al Arenero #1227, Col. El Bajío Arenal, 45019 Zapopan, Jalisco, Mexico.
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Manikandan DB, Arumugam M, Sridhar A, Perumalsamy B, Ramasamy T. Sustainable fabrication of hybrid silver-copper nanocomposites (Ag-CuO NCs) using Ocimum americanum L. as an effective regime against antibacterial, anticancer, photocatalytic dye degradation and microalgae toxicity. ENVIRONMENTAL RESEARCH 2023; 228:115867. [PMID: 37044164 DOI: 10.1016/j.envres.2023.115867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 04/05/2023] [Accepted: 04/08/2023] [Indexed: 05/16/2023]
Abstract
In this study, a sustainable fabrication of hybrid silver-copper oxide nanocomposites (Ag-CuO NCs) was accomplished utilizing Ocimum americanum L. by one pot green chemistry method. The multifarious biological and environmental applications of the green fabricated Ag-CuO NCs were evaluated through their antibacterial, anticancer, dye degradation, and microalgae growth inhibition activities. The morphological features of the surface functionalized hybrid Ag-CuO NCs were confirmed by FE-SEM and HR-TEM techniques. The surface plasmon resonance λmax peak appeared at 441.56 nm. The average hydrodynamic size distribution of synthesized nanocomposite was 69.80 nm. Zeta potential analysis of Ag-CuO NCs confirmed its remarkable stability at -21.5 mV. XRD and XPS techniques validated the crystalline structure and electron binding affinity of NCs, respectively. The Ag-CuO NCs demonstrated excellent inhibitory activity against Vibrio cholerae (19.93 ± 0.29 mm) at 100 μg/mL. Anticancer efficacy of Ag-CuO NCs was investigated against the A549 lung cancer cell line, and Ag-CuO NCs exhibited outstanding antiproliferative activity with a low IC50 of 2.8 ± 0.05 μg/mL. Furthermore, staining and comet assays substantiated that the Ag-CuO NCs hindered the progression of the A549 cells and induced apoptosis as a result of cell cycle arrest at the G0/G1 phase. Concerning the environmental applications, the Ag-CuO NCs displayed efficient photocatalytic activity against eosin yellow degradation up to 80.94% under sunlight irradiation. Microalgae can be used as an early bio-indicator/prediction of environmental contaminants and toxic substances. The treatment of the Ag-CuO NCs on the growth of marine microalgae Tetraselmis suecica demonstrated the dose and time-dependent growth reduction and variations in the chlorophyll content. Therefore, the efficient multifunctional properties of hybrid Ag-CuO NCs could be exploited as a regime against infective diseases and cancer. Further, the findings of our investigation witness the remarkable scope and potency of Ag-CuO NCs for environmental applications.
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Affiliation(s)
- Dinesh Babu Manikandan
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Manikandan Arumugam
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Arun Sridhar
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Balaji Perumalsamy
- National Centre for Alternatives to Animal Experiments (NCAAE), Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Thirumurugan Ramasamy
- Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India; National Centre for Alternatives to Animal Experiments (NCAAE), Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India.
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Samim AR, Singh VK, Vaseem H. Assessment of hazardous impact of nickel oxide nanoparticles on biochemical and histological parameters of gills and liver tissues of Heteropneustes fossilis. J Trace Elem Med Biol 2022; 74:127059. [PMID: 35987181 DOI: 10.1016/j.jtemb.2022.127059] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/31/2022] [Accepted: 08/02/2022] [Indexed: 11/20/2022]
Abstract
BACKGROUND The aim of the present study was to assess the hazardous impact of nickel oxide nanoparticles (NiO NPs) on gills and liver of Heteropneustes fossilis. METHODS Fishes were treated with four concentrations of NiO NPs for a period of 14 days. Nickel accumulation, lipid peroxidation, antioxidant enzymes activities (superoxide dismutase, catalase, glutathione s transferase & glutathione reductase), liver enzymes activities (aspartate amino transferase, alanine transaminase, & alkaline phosphatase), Na+/K+ ATPase activity, FTIR, metallothionein content, ethoxyresorufin-o-deethylase activity, immunohistochemistry, histology and scanning electron microscopy were analyzed in both gills and liver tissues. RESULTS Results revealed increased accumulation of nickel in both the tissues of exposed fishes. Lipid peroxidation and activities of different antioxidant enzymes increased (except superoxide dismutase) in both the tissues after exposure. Fluctuations in liver enzymes activities and variation in the activity of Na+/K+ ATPase were also observed. FTIR data revealed shift in peaks position in both the tissues. Level of metallothionein and its expression as well as activity of ethoxyresorufin-o-deethylase and expression of CYP1A also increased in both the target tissues of treated fishes. Furthermore, histological investigation and scanning electron microscopy showed structural damages in gills as well as liver tissues of exposed fishes. CONCLUSION Our results suggest that NiO NPs cause deteriorating effects on the gill and liver tissues of fish, therefore effluents containing these nanoparticles should be treated before their release into water bodies.
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Affiliation(s)
- Abdur Rouf Samim
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
| | - Vinay Kumar Singh
- Department of Zoology, CMP Degree College, University of Allahabad, Prayagraj 211002, India.
| | - Huma Vaseem
- Department of Zoology, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.
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Andronic L, Mamedov D, Cazan C, Popa M, Chifiriuc MC, Allaniyazov A, Palencsar S, Karazhanov SZ. Cerium oxide thin films: synthesis, characterization, photocatalytic activity and influence on microbial growth. BIOFOULING 2022; 38:865-875. [PMID: 36345787 DOI: 10.1080/08927014.2022.2144264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
The resistance of surfaces to biofouling remains a significant advantage for optical devices working in natural conditions, increasing their lifetime and reducing maintenance costs. This paper reports on the functionalities of transparent CeO2 thin films with thicknesses between 25 and 600 nm deposited by reactive magnetron sputtering on the glass substrate. The CeO2 photocatalytic performance exhibited an efficiency of 30% on imidacloprid degradation under 6 h of UV radiation and increased linearly with the irradiation time, suggesting a complete degradation within 48 h. The films did not alter the growth rate of the green algae Chlorella vulgaris after 72 h short-term exposure. The tested CeO2 films proved to efficiently inhibit with high efficiency the Staphylococcus aureus biofilms and planktonic growth (reducing the counts of bacterial cells by 2 to 8 logs), demonstrating the promising potential of these materials for obtaining antimicrobial and antibiofilm surfaces, with broad applications for the biomedical, ecological and industrial fields.
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Affiliation(s)
- Luminita Andronic
- Product Design, Mechatronics and Environment Department, Transilvania University of Brasov, Brasov, Romania
| | - Damir Mamedov
- Department for Solar Energy, Institute for Energy Technology, Kjeller, Norway
- Department of Materials Science, Moscow Engineering Physics Institute, Moscow, Russia
| | - Cristina Cazan
- Product Design, Mechatronics and Environment Department, Transilvania University of Brasov, Brasov, Romania
| | - Marcela Popa
- Microbiology Immunology Department, Faculty of Biology, The Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
| | - Mariana Carmen Chifiriuc
- Microbiology Immunology Department, Faculty of Biology, The Research Institute of the University of Bucharest (ICUB), University of Bucharest, Bucharest, Romania
- The Romanian Academy, Bucharest, Romania
- Academy of Romanian Scientists, Bucharest, Romania
| | | | - Simona Palencsar
- Department for Corrosion Technology, Institute for Energy Technology, Kjeller, Norway
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Khalifeh F, Salari H, Zamani H. Mechanism of MnO 2 nanorods toxicity in marine microalgae Chlorella sorokiniana during long-term exposure. MARINE ENVIRONMENTAL RESEARCH 2022; 179:105669. [PMID: 35667325 DOI: 10.1016/j.marenvres.2022.105669] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/24/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Due to the increasing production and use of nanomaterials (NMs), their potential toxic impacts on the environment should be considered for a safe application of NMs. In this regard, the potential hazards of MnO2 nanorods (NRs) on the green microalgae Chlorella sorokiniana during long-term exposure were investigated. Exposure to the high concentration of MnO2 NRs (100 and 200 mg L-1) significantly reduced the cell number of C. sorokiniana over 20 days of the experiment. The different concentrations of MnO2 NRs (25-200 mg L-1) induced the remarkable increase in the chlorophyll (a+b) content of algal cells due to the shading effect of NRs. For more than 72 h, the chlorophyll content of microalgae decreased due to the aggregation of NRs and the possible effects of oxidative stress. Long-term exposure to high concentrations of NRs caused a significant decrease in the primary and secondary metabolites of microalgae, including carotenoids, phenolic compounds, proteins, lipids, and carbohydrates. Oxidative stress was one of the possible toxic mechanisms of MnO2 NRs to microalgae validated by an increase in lipid peroxidation induced by exposure to NRs. The algal cells increased the catalase activity and the amount of extracellular polymeric substances in response to NRs toxicity. The low level of Mn ions in the culture media indicated that MnO2 NRs dissolution was not the cause of the observed reduction in the microalgae growth. Moreover, the bulk form of MnO2 was not involved in the toxic impact of MnO2, which was documented by an insignificant decrease in the growth, pigment, and lipid peroxidation of C. sorokiniana. These results may provide an additional insight into the potential hazards of MnO2 NRs on the aquatic ecosystem.
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Affiliation(s)
- Fatemeh Khalifeh
- Department of Biology, School of Science, Shiraz University, Shiraz, Iran
| | - Hadi Salari
- Department of Chemistry, School of Science, Shiraz University, Shiraz, Iran
| | - Hajar Zamani
- Department of Biology, School of Science, Shiraz University, Shiraz, Iran.
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Synthesis, Characterisation, Photocatalytic Activity, and Aquatic Toxicity Evaluation of TiO 2 Nanoparticles. NANOMATERIALS 2021; 11:nano11123197. [PMID: 34947548 PMCID: PMC8709270 DOI: 10.3390/nano11123197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/12/2021] [Accepted: 11/24/2021] [Indexed: 12/21/2022]
Abstract
Imidacloprid (IMD) is a toxic pesticide, and is one of the eight most widely used pesticides globally. Heterogeneous photocatalysis has often been investigated in recent years and can be successfully applied to remove imidacloprid from water. However, less investigated is the toxic effect of both the photocatalyst and the pesticide on aquatic life. Titanium dioxide (TiO2) remains the most effective photocatalyst, provided it is not toxic to the aquatic environment. This study investigated the TiO2 synthesis, characterisation, and photocatalytic activity on imidacloprid degradation and the toxicity of TiO2 nanoparticles and imidacloprid on the green algae Chlorella vulgaris. In the photodegradation process of IMD (initial concentration of 20 mg/L), electrons play an essential role; the degradation efficiency of IMD after 6 h increased from 69 to 90% under UV irradiation when holes (h+) scavengers were added, which allowed the electrons to react with the pollutant, resulting in lowering the recombination rate of electron-hole charge carriers. Growth inhibition of Chlorella vulgaris and effective concentration (EC50) were determined to study the toxic effect of TiO2 nanoparticles and imidacloprid. The EC50 increased from 289.338 mg/L in the first 24 h to 1126.75 mg/L after 96 h Chlorella vulgaris algal age, when the toxicant was TiO2. When IMD was the aquatic toxicant, a decrease in EC50 was observed from 22.8 mg/L (24 h) to 0.00777 mg/L (120 h), suggesting a long-term high toxicity level when pesticides in low concentrations are present in an aquatic environment.
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Adochite C, Andronic L. Toxicity of a Binary Mixture of TiO 2 and Imidacloprid Applied to Chlorella vulgaris. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18157785. [PMID: 34360075 PMCID: PMC8345346 DOI: 10.3390/ijerph18157785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/18/2021] [Accepted: 07/21/2021] [Indexed: 11/16/2022]
Abstract
Nanoparticles have applications in various fields such as manufacturing and materials synthesis, the environment, electronics, energy harvesting, and medicine. Besides many applications of nanoparticles, further research is required for toxic environmental effect investigation. The toxic effect of titanium dioxide nanoparticles on the physiology of the green alga Chlorella vulgaris was studied with a widely used pesticide, imidacloprid (IMD). Chlorella vulgaris was exposed for 120 h in Bold's basal medium to different toxic compounds, such as (i) a high concentration of TiO2 nanoparticles, 150-2000 mg/L, usually optimised in the photocatalytic degradation of wastewater, (ii) an extremely toxic pesticide for the aquatic environment, imidacloprid, in concentrations ranging from 5 to 40 mg/L, (iii) TiO2 nanoparticles combined with imidacloprid, usually used in a photocatalytic system. The results show that the TiO2 nanoparticles and IMD inhibited Chlorella vulgaris cell growth and decreased the biovolume by approximately 80% when 2 g/L TiO2 was used, meaning that the cells devised a mechanism to cope with a potentially stressful situation; 120 h of Chlorella vulgaris exposure to 40 mg/L of IMD resulted in a 16% decreased cell diameter and a 41% decrease in cell volume relative to the control sample, associated with the toxic effect of pesticides on the cells. Our study confirms the toxicity of nanoparticles through algal growth inhibition with an effective concentration (EC50) value measured after 72 h of 388.14 mg/L for TiO2 and 13 mg/L for IMD in a single-toxic system. The EC50 of TiO2 slowly decreased from 258.42 to 311.11 mg/L when IMD from 5 to 20 mg/L was added to the binary-toxic system. The concentration of TiO2 in the binary-toxic system did not change the EC50 for IMD, and its value was 0.019 g/L. The photodegradation process of imidacloprid (range of 5-40 mg/L) was also investigated in the algal medium incubated with 150-600 mg/L of titanium dioxide.
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El-Sheekh MM, El-Kassas HY, Shams El-Din NG, Eissa DI, El-Sherbiny BA. Green synthesis, characterization applications of iron oxide nanoparticles for antialgal and wastewater bioremediation using three brown algae. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2021; 23:1538-1552. [PMID: 33899605 DOI: 10.1080/15226514.2021.1915957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study aims at controlling excess nutrients, including nitrogen and phosphorus, and harmful algae that pollute the marine environment using biosynthesized iron oxide nanoparticles. Aqueous extracts of brown seaweeds named Petalonia fascia, Colpomenia sinuosa, and Padina pavonica were selected for iron oxide nanoparticles' biosynthesis. The extracts were used as reductants of ferric chloride, and dark brown colors due to Fe3O4-NPs biosynthesis were observed. Iron signals were recorded in EDX spectra. FTIR analyses showed that the three algae extracts contained proteins and lipids that have the ability to proceed dual functions of bioreduction and stabilization of Fe3O4-NPs, suggesting that proteins in P. fascia, C. sinuosa, and P. pavonica extracts reduced FeCl3, and the aromatic compounds stabilized the biogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs via P. pavonica had the best nitrogen reduction percentage, followed by C. sinuosa and P. fascia for both concentrations 2 and 4 µg mL-1. The best results of phosphorus removal and Chlorophyll a (Chl a) reduction percentages using the Fe3O4-NPs concentrations were 2 and 4 µg mL-1 with nanoparticles synthesized via P. fascia and P. pavonica, respectively. The highest reduction in optical density for both 2 and 4 µg mL-1 was achieved by the nanoparticles synthesized by P. fascia. Novelty StatementApplication of nanoparticles using seaweeds extracts could be alternative safe bioremediation of wastewaters. Currently, iron oxide nanoparticles are used to reduce nitrogen and phosphorus and reduce the blooming of harmful algae; little information about this issue has been reported. Such study also presented the anti-algal impacts of Fe3O4-NPs by tracing optical density and Chl a concentrations in the examined real seawater samples. Modern biotechnology to develop phytoremediation and seaweeds to enhance these remediation methods can be adopted.
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Affiliation(s)
| | - Hala Y El-Kassas
- National Institute of Oceanography and Fisheries, Alexandria, Egypt
| | | | - Doria I Eissa
- Botany Department, Faculty of Science, Tanta University, Tanta, Egypt
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Preparation of PANI Modified ZnO Composites via Different Methods: Structural, Morphological and Photocatalytic Properties. WATER 2021. [DOI: 10.3390/w13081025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Polyaniline modified zinc oxide (PANI-ZnO) photocatalyst composites were synthesized by focusing on dissolution disadvantage of ZnO. In-Situ chemical oxidation polymerization method was performed under neutral conditions (PANI-ES) whereas in hybridization method physical blending was applied using emeraldine base of polyaniline (PANI-EB). PANI-ZnO composites were prepared in various ratios of aniline (ANI) to ZnO as 1%, 3%, 6% and 9%. The alterations on the structural and morphological properties of PANI-ZnO composites were compared by Fourier Transform Infrared (FT-IR), Raman Spectroscopy, X-ray Diffraction (XRD) and Scanning Electron Microscopy-Energy Dispersive X-ray Analysis Unit (SEM-EDAX) techniques. FT-IR and Raman spectroscopy confirmed the presence of PANI in all composites. SEM images revealed the morphological differences of PANI-ZnO composites based on PANI presence and preparation methods. Photocatalytic performances of PANI-ZnO specimens were investigated by following the degradation of methylene blue (MB) in aqueous medium under UVA irradiation. The effects of catalyst dose and initial dye concentration were also studied. MB degradation was followed by both decolorization extents and removal of aromatic fractions. PANI-ZnO composites expressed enhanced photocatalytic performance (~95% for both methods) as compared to sole ZnO (~87%). The hybridization method was found to be more efficient than the In-Situ chemical oxidation polymerization method emphasizing the significance of the neutral medium.
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