Synthesis of silver, copper, iron nanoparticles and their applications in controlling cyanobacterial in the fresh water body

TRAN THI THU HUONG SYNTHESIS OF SILVER, COPPER, IRON NANOPARTICLES AND THEIR APPLICATIONS IN CONTROLLING CYANOBACTERIAL IN THE FRESH WATER BODY Major: Environmental Technique Code: 9 52 03 20 SUMMARY OF ENVIRONMENTAL TECHNIQUE DOCTORAL THESIS HaNoi - 2018 MINISTRY OF EDUCATION AND TRAINING VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY --------------------------- The thesis was completed at the Graduate University of Science and Technology, Vietnam Academy of Science and Technology Scientific Supervisor 1: Assoc. Prof. Dr. Duong Thi Thuy Scientific Supervisor 2: Dr. Ha Phuong Thu Reviewer 1: Reviewer 2: Reviewer 3: The dissertation will be defended protected at the Council for Ph.D. thesis, meeting at the Viet Nam Academy of Science and Technology - Graduate University of Science and Technology. Time: Date month . 2018 This thesis can be found at: - The library of the Graduate University of Science and Technology. - National Library of Viet Nam. 1 INTRODUCTION OF THESIS 1. The necessary of the thesis In recent years, pollution of soil, water and air has become a serious problem not only in Vietnam but also in many parts of the world in which the water pollution is more serious problem. "Water blooming" is the development of microalgae outbreak, especially cyanobacteria in fresh water bodies and often cause the harmful effects on the environment such as: the water turbidity and pH are increase, the levels of dissolved oxygen is reduce due to the respiration or degradation of algae biomass and especially, the fact that most cyanobacteria produce the toxicity high. The preventing and minimizing the development of cyanobacteria is an important environmental issue that need to pay the attention. The many methods have been used such as: chemistry, mechanics, biology, etc., but they are ineffective and expensive, affecting ecosystem and conducting is difficult, especially in large water bodies. Therefore, the search and development of new effective solutions without secondary pollution and friendly with the environment are increasingly focused research. Nanotechnology is the technology relating to the synthesis and application of materials with nanometer sizes (nm). At nanoscale, the material has many advantage features such as: size is smaller than 100 nm, larger surface to volume ratio, crystalline structure, high reactivity potential, creating the effect of resonance Plasmon surface; high adhesion potential and the nanomaterial was applied in various fields such as: medical, cosmetics, electronics, chemical catalyst, environment... For the above reasons, the thesis is proposed as: “Synthesis of silver, copper, iron nanoparticles and their applications in controlling cyanobacterial blooms in the fresh water body” was selected to researched. 2. The objectives of the thesis Research, fabricate and determine the characteristic of three nanomaterials (silver, copper and iron) and evaluate the ability to inhibit the cyanobacteria of nanomaterials in fresh water bodies. 3. The main contents of the thesis - Fabricate and determine the characteristic of three nanomaterials: silver, copper and iron. 2 - Investigate the ability to inhibit and prevent cyanobacteria of three nanomaterials. - Assess the safety of materials and their application. - Experimental application of materials at laboratory-scale with the Tien lake water sample. 5. The structure of the thesis The thesis is composed of 149 pages, 10 tables, 62 figures, 219 references. The thesis consists of three parts: Introduction (3 pages); chapter 1: Literature review (42 pages); chapter 2: Methodology (16 pages); chapter 3: Resutl and discussion (59 pages); Conclusion and recommendation (2 pages). CHAPTER 1. LITERATURE REVIEW 1.1. Introduction of nanomaterial 1.2. Introduction of Cyanobacteria and Eutrophication 1.3. Introduction of the methods to treat the toxic algae contamination CHAPTER 2. METHODOLOGY 2.1. The research subjects 2.2. The equipment is used in study 2.3. The methods for synthesis of materials 2.3.1. Synthesis of silver nanomaterial by chemical reduction method The silver nanomaterial was synthesized by chemical reduction method, ion Ag + in the silver salt solution is reducted to Ag 0 by the reducing agent NaBH4. 2.3.2. Synthesis of copper nanomaterial by chemical reduction method The copper nanomaterial was synthesized by chemical reduction method, ion Cu 2+ in the copper salt solution is reduced to Cu 0 by the reducing agent NaBH4. 2.3.3. Synthesis of iron magnetic (Fe3O4) nanomaterial by simultaneously precipitation method The iron magnetic (Fe3O4) nanomaterial was synthesized by simultaneously precipitation method of Fe 2+ and Fe 3+ salts by NH4OH. 2.4. The methods for determining the characteristic of material structure 3 The morphology of the three nanomaterials is determined by a number of methods such as: TEM, SEM, IR, XRD, UV-VIS, EDX. 2.5. The experimental setup methods The experimental setup methods such as: culture of algae, selection of nanomaterials, evaluation of the material toxicity, the evaluation of the influence of nanomaterial sizes and the safety of nanomaterials on microalgae and the experiment with the Tien lake water sample were setup. 2.6. The methods of evaluating the effect of nanomaterials on the growth of microalgae To evaluate the effect of nanomaterials on the growth of microalgae, the following methods such as: OD, chlorophyll a, cell density, the methods for analysis of some environmental quality indicators (NH4 + , PO4 3- ) and SEM, TEM were used. 2.7. The method of statistical analysis CHAPTER 3. RESUTL AND DISCUSSION 3.1. Synthesis of nanomaterial 3.1.1. Synthesis of silver nanomaterial by chemical reduction method 3.1.1.1. Effect of the concentration ratio NaBH4/Ag + The UV-VIS spectrophotometer (Fig 3.1) showed that the nanosilver colloid was absorbed at the wavelengths about 400 nm and the synthesized efficiency of silver nanoparticles was maximum achieved at a ratio 1:2. TEM images (Figure 3.2) showed that silver nanoparticle size was less than 20 nm. Figure 3.1. The UV-VIS spectra of nanosilver colloid depends on the NaBH4/Ag + concentration ratios Figure 3.2. The TEM images of nanosilver colloid depends on the BH4 - /Ag + concentration ratio M3 M4 M5 M1 M2 4 3.1.1.2. Effect of stabilizer concentration chitosan The UV-VIS measurements in Figure 3.4 showed that the nanosilver colloid is absorbed at the wavelengths 402-411 nm. The TEM image of the silver nanoparticles depends on the concentration of chitosan shown in Figure 3.5. The optimum chitosan concentration of nanosilver colloid fabricating was chosen as 300 mg/L. Figure 3.4. The UV-VIS spectra of nanosilver colloid depends on chitosan concentrations Figure 3.5. The TEM images of nanosilver colloid depends on the chitosan concentrations 3.1.1.3. Effect of citric acid concentration The UV-VIS measurements in Figure 3.7 showed that the nanosilver colloid is absorbed at the wavelengths 402-411 nm. At the rate of [Citric]/[Ag + ] = 3.0 the silver nanoparticles obtained were of the most uniform, small size and less than 20 nm, the TEM measurement is shown in Figure 3.8. Figure 3.7. The UV-VIS spectra of nanosilver colloid depends on acid concentration Figure 3.8. The TEM images of nanosilver colloid depends on the [Citric]/[Ag + ] concentration M6 M7 M8 M9 M10 M11 M12 M13 M14 M15 M16 5 Figure 3.9. The HR-TEM of nanosilver colloid was tested at optimal ratio The structure of silver nanoparticle at the optimum ratio indicates that they have a typical hexagon crystal structure of metallic nanoparticles. The HR-TEM images in Figure 3.9 showed that the crystals has got Fcc (Face-centered cubic) structure. The silver nanomaterial at the conditions such as: the ratio of NaBH4/Ag + is 1/4, the [Citric]/[Ag + ] is 3.0 and a concentration of chitosan stabilizer is 300 mg/L were synthesized to experimented the effect of material on the growth of the studied subjects in the thesis. 3.1.2. Synthesis of copper nanomaterial by chemical reduction method 3.1.2.1. Effect of the concentration ratio NaBH4/Cu 2+ The results in Figure 3.10 show that, in the XRD spectrum appears the three peak with the intensity match for the standard spectra of the copper metal at the side (111), (200), (220) corresponding to angle 2θ = 43.3; 50.4 and 74.00 belong to the Bravais network in the fcc structure of the copper metal. Figure 3.10. The XRD pattern of CuNPs were tested in NaBH4/Cu 2+ concentration Figure 3.11. The SEM images of CuNPs in NaBH4/Cu 2+ ratio The SEM measurements (Fig 3.11) of the material were performed to determine the distribution of the copper particles and M1 M2 M3 M4 M5 6 the TEM measurement for determine the size of copper nanoparticles (Fig 3.12). Figure 3.12. The TEM images of CuNPs in NaBH4/Cu 2+ ratio Figure 3.13. The XRD spectrum of CuNPs was tested by Cu 0 concentration The TEM image results showed that, when the NaBH4/Cu 2+ concentration ratio is 1: 1 and 1.5: 1, the size of synthesized copper nanoparticles are bigger than 50 nm. The nanoparticles are distributed rather uniformly with a size about 20-50 nm when the NaBH4/Cu 2+ ratio is 2 : 1. The nanoparticles are clumped together, unevenly distributed with the size nanoparticle > 50 nm when the NaBH4/Cu 2+ ratio is 3: 1 and 4: 1 and match with the SEM results. To respone the objective of this thesis, the M3 sample (NaBH4/Cu 2+ ratio is 2: 1) was chosen as the representative sample. 3.1.2.2. Effect of Cu 0 concentration XRD spectrum in Figure 3.13 showed that the of copper nanoparticles presents the characteristic peaks of copper nanomaterial. The characteristic peaks on the schematic have the sharpness intensity and the wide range of the absorption peak relatively narrow. In addition, the XRD spectrum of the material also shows the characteristic peaks of CuO, Cu2O crystals. The SEM (Fig 3.14) measurement results showed that, the copper nanoparticles form of the unequal size distribution when the concentration of Cu 0 increases. At concentrations of Cu 0 is 2g/L, the copper nanoparticles are distributed rather uniformly with the size at 20-40 nm. When the concentration of Cu 0 increases to 3; 4g/L, the synthesized copper particles will clump together and form of the particle sizes >50 nm; at Cu 0 concentration is 6, 7 g/L, M1 M2 M3 M4 M5 7 the nanoparticles distributed unevenly and match for the TEM measurement (Fig 3.15). Figure 3.14. The SEM image of copper nanomaterial was tested at Cu 0 concentration Figure 3.15. The TEM image of copper nanomaterial was tested at Cu 0 concentration a) b) Faculty of Chemistry, HUS, VNU, D8 ADVANCE-Bruker - Cu-51 01-085-1326 (C) - Copper - Cu - Y: 16.13 % - d x by: 1. - WL: 1.5406 - Cubic - a 3.61500 - b 3.61500 - c 3.61500 - alpha 90.000 - beta 90.000 - gamma 90.000 - Face-centered - Fm-3m (225) - 4 - 47.2416 - I/Ic PDF 8.9 - F4 1) File: ThuyVCNMT Cu-51.raw - Type: 2Th/Th locked - Start: 1.000 ° - End: 79.990 ° - Step: 0.030 ° - Step time: 0.3 s - Anode: Cu - WL1: 1.5406 - Generator kV: 40 kV - Generator mA: 40 mA - Creation: 06/10/2016 3:54:39 P Left Angle: 42.490 ° - Right Angle: 44.350 ° - Obs. Max: 43.281 ° - d (Obs. Max): 2.089 - Max Int.: 1890 Cps - Net Height: 1668 Cps - FWHM: 0.231 ° - Raw Area: 852.6 Cps x deg. - Net Area: 440.4 Cps x deg. L in ( C p s ) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 2-Theta - Scale 1 10 20 30 40 50 60 70 80 d = 2 .0 8 9 d = 1 .8 0 8 d = 1 .2 7 8 c) Figure 3.16. The detail characteristics of the N1 copper nanomaterials sample: (a) SEM image, (b) TEM image, (c) XRD spectrum The structure of copper nanomaterial at selected ratio showed that, the formed copper nanoparticles have the rather homogeneous surface (SEM image, Fig 3.16a), the uniformly size in the range of 30 - 40 nm (TEM image, Fig 3.16b) and have the Fcc structure with diffraction peaks of the netface (111), (200) and (220) corresponding to angle 2θ = 43.3; 50.4 and 74.00 with high intensity (XRD spectrum, Fig 3.16c). This material sample is suitable with the objective of the thesis and were choosen for further experiment. N1 N2 N3 N4 N5 N1 N2 N3 N4 N5 8 3.1.3. Synthesis of magnetic solution nanomaterial by co- precipitation method 3.1.3.1. Effect of the CMC stabilizer concentration The tested result of morphological, size and the dispersion of material in the ratio of CMC stabilizer and precursor (Fe3O4) respectively were 1/1; 2/1; 3/1; 4/1 and 1/2 by the SEM and methods shown in Figure 3.17 and 3.18. The SEM result showed that the concentration of CMC in the solution is high, the ferromagnetic nanoparticles are unevenly and the particle size is big, the accumulation of nanoparticles is easy to occur. At the rate of CMC/Fe3O4 is 2/1, the obtained ferromagnetic nanoparticles are uniformly sized and less 20 nm. Figure 3.17. The SEM image of magnetic solution nanostructure tested in ratios of CMC/Fe3O4 Figure 3.18. The TEM image of magnetic solution nanostructure tested in ratios of CMC/Fe3O4 The TEM results showed that the nanoparticle size varies considerably when the CMC concentrations changed. When the Fe3O4/CMC is 2:1, the obtained nanoparticles were the smallest, most uniform and less than 20nm within the superparamagnetic size range. Therefore, the material sample has a Fe3O4/CMC ratio of 2:1 (encoded sample is FC21) selected to tested for the further factors. 3.1.3.2. The result of infrared measurement of the material Figure 3.19. The infrared spectrum of Fe3O4 (a), CMC (b), FC21 (c) and spectrum of three samples (d) Figure 3.20. The magnetization hysteresis result of material FC21 9 The observation in Figure 3.19 showed that the IR spectrum of ferromagnetic nanoparticles have peaks similar with CMC and Fe3O4, this proves that the structure of CMC is not broken by the material synthesis conditions. Therefore, the co-precipitation method for synthesis of material is suitable for purity as well as efficiency. 3.1.3.3. The magnetization hysteresis result of material The result of saturate magnetization hysteresis measurement in Figure 3.20 showed that ferromagnetic nanoparticles are in the form of superparamagnetic. The saturate magnetization of Fe3O4 and FC21 is 68 emu/g and 49 emu/g, corresponding to the content of magnetic phase of the material. The result proves that the surface interaction of the magnetic phase with the polymer decreased the saturate magnetization and suitable with the results of the TEM analysis. 3.2. Evaluating the ability of growth inhibition and prevent microalgae by synthesized nanomaterials 3.2.1. Study on the selection of concentrations of three types of nanomaterials Table 3.1. The screening results of removal M. aeruginosa KG cyanobacteria of fabricated nanomaterials No. Samples Experimental concentration (mg/L) The growth inhibition of cyanobacteria 1 Ag nano 3, 5 and 10 +++ 3 Cu nano 3, 5 and 10 +++ 5 Fe3O4 nano 5, 10, 100, 150 and 200 - 6 Control 0 - Notes: +++: Very strong inhibitory effect, ++: Strong inhibitory effect, +: Normal inhibitory effect, -: Non inhibitory effect. Figure 3.21. Effect of nanomaterials on growth of cyanobacteria M. aeruginosa KG after for 7 days. 10 The concentration screening tests were conducted to rapidly assess inhibition effect to M. aeruginosa KG for 7 days. The results in Table 3.1 and Figure 3.21 showed that the two silver and copper nanomaterials inhibited the growth and development of cyanobacteria M. aeruginosa KG after 6 days (Table 3.1 and Fig 3.21a, b), whereas that the ferromagnetic nanomaterial were not effective against M. aeruginosa KG (Table 3.1 and Fig 3.21c). 3.2.2. Effect of silver nanoparticles on growth and development of cyanobacteria M. aeruginosa KG and green algae C. vulgaris 3.2.2.1. Effect of silver nanoparticles on growth and development of cyanobacteria M. aeruginosa KG The experiments were conducted with the concentrations of silver nanoparticles increasing from 0; 0.001; 0.005; 0.01; 0.05; 0.1 to 1 ppm in 10 days. The evaluation parameters include: optical density (OD), chlorophyll a and cell density at 0, 2, 6 and 10 days (Fig 3.22a, b). The toxicity of silver nanoparticles on growth of the cyanobacteria M. aeruginosa KG as measured by the concentration of supplementary material into the culture medium that affected 50% of the individuals (EC50) was 0.0075 mg/L. Figure 3.22. Effect of silver nanomaterial on growth of the cyanobacteria M. aeruginosa KG after 10 days was measured by (OD) (a), chlorophyll a (b) Figure 3.23. Effect of silver nanomaterial was measured by the cell density (a) and the growth inhibition efficiency on cyanobacteria M. aeruginosa KG (b) The cell density and chlorophyll a showed that, the cell density and biomass in the control sample increased from the first day (D0) (110,741 ± 6,317 cells/mL and 1.98 ± 0.06 μg/L, respectively) to the end of experiment (D10) (5,475, 556 ± 541,274 cells/mL and 23.4 ± 2.96 μg/L, respectively) (Fig 3.23a). All five tested concentration ranges are toxic to cyanobacteria M. aeruginosa KG. The growth 11 inhibition efficiency (Fig 3.23b) > 75% appears in only 4 tested concentrations from 0.01; 0.05; 0.1 and 1 ppm. The SEM image result of cell surface structure after 48h exposed to silver nanoparticles at the concentration of 1 ppm is shown in Figures 3.24a (the control sample) and 3.24b (the sample exposed to the concentration of 1ppm silver nanoparticles). In the control sample, the morphological of cyanobacteria M. aeruginosa KG cells maintained a round and had a spherical shape with a smooth exterior surface (Fig 3.24a). In the experimental sample, the cells were changed to with a distorted and shrunk cell after exposure to silver nanoparticles (Fig 3.24b). It is said that the silver nanoparticles have significantly altered the morphology of the cell. Figure 3.24. Scanning Electron Microscopy (SEM) micrograph of M. aeruginosa KG Figure 3.26. Transmission Electron Microscopy (TEM) micrograph of M. aeruginosa KG The SEM combined with EDX analysis was used to characterize the chemical composition and the location of AgNPs on the cell surface of M. aeruginosa KG. The EDX result in Figure 3.25 showed that the silver nanoparticles appear on the surface of the cyanobacteria M. aeruginosa KG with 0.37% Ag by weight. The TEM image in the control sample (Fig 3.26a), the M. aeruginosa KG ultrastructure image had clearly cell wall and the organelle lie neatly in the cell. When exposed to silver nanoparticles at a concentration of 1ppm after 48 hours, the cyanobacteria cells were destroyed (Fig 3.26b). It is proved that the silver nanoparticles was affected to structure of the cyanobacteria M. aeruginosa KG cell. Elements % Weight % Element C K 38.69 55.90 O K 30.59 33.18 Na K 1.95 1.47 Al K 6.02 3.87 Cu L 11.82 3.23 Ag L 0.37 0.06 a) b) a) b) 12 Totals 100.00 Figure 3.25. The EDX spectrum and the element composition appear on the cell surface of M. a