Elimination of Cypermethrin using Fe-TiO 2 2 nanoparticles supported on coconut palm spathe 3 using a solar flat plate photoreactor 4

In this research, the photocatalytic degradation of cypermethrin using Fe-TiO2 10 nanoparticles supported in a biomaterial was evaluated. The nanoparticles of TiO2 were synthesized 11 by the green chemistry method assisted by ultrasound and doped by chemical impregnation using 12 molar ratios Fe:Ti of 0, 0.05, 0.075 and 0.1, to make efficient use of direct sunlight (λ>310 nm). All 13 nanoparticles were immobilized on the surface of spathe of coconut palm (Cocos nucifera). The 14 degradation was carried out at room temperature and natural pH in a flat plate solar reactor, on 15 which the composite material was subjected. The concentration of cypermethrin was determined 16 after 12000 J/m2 of accumulated radiation from GC-MS and the resulting material was characterized 17 by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) image and 18 selected area electron diffraction (SAED), Fourier transform infrared spectroscopy (FTIR), UV-Vis 19 spectrophotometry of diffuse reflectance and BET surface area BET surface area. The best results 20 were achieved with the use of Degussa TiO2 P-25, Fe:Ti=0 and Fe:Ti=0.05 in suspension, with 21 percentages of degradation of cypermethrin of 99.84, 99.62, and 100%, respectively. However, the 22 materials supported on the biomaterial of coconut, they allowed to reach degradation percentages 23 higher than 80% with the advantage that it minimizes operating costs, since they are not necessary 24 filtering or centrifuging processes to separate the catalyst. 25


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The current paradigm of the intensification of pest control in agriculture has increased the 29 demand for pesticides, because these have become fundamental tools in the productivity of the

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The excessive amount of pesticide residues in the soil, surface water and groundwater causes serious 37 contamination of soil and water, due to its high toxicity and persistence, which has been declared as drainage and discharges of pesticide production plants [14].

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In urban wastewater treatment plants, biological treatment does not eliminate polar, toxic or 49 non-biodegradable contaminants, although it is adopted as the best available technology. To comply 50 with strict environmental laws, significant efforts are being made to develop effective, rational and 51 affordable wastewater treatment strategies, and improvements in processes that can easily destroy 52 all bio-recalcitrant organic pollutants, minimizing their accumulation [15]. Advanced oxidation 53 processes (AOPs) are characterized by the "insitu" production of hydroxyl radicals (OH•), which are 54 capable of oxidizing and mineralizing any organic molecule, producing CO2, H2O and inorganic ions.

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Due to the reactivity of the hydroxyl radicals, its attack is non-selective, which is useful for the 56 treatment of wastewater containing different pollutants. AOPs can be made with solar irradiation, 57 since the sun (a source of clean renewable energy) provides photons with the wavelength required 58 for these processes [8,9,[16][17][18]. Heterogeneous Photocatalysis is an advanced oxidation technology 59 for the degradation of persistent organic pollutants, such as pesticides, which produces byproducts 60 that are more biodegradable than the original compounds. TiO2 is the most common photocatalyst in

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In a similar study, the batch degradation of atrazine was evaluated using B-TiO2 nanomaterials, with 68 efficiencies close to 85% in the photocatalytic process [30]. Additionally, heterogeneous 69 photocatalysis has been integrated with other advanced oxidation processes such as ozonation. The

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O3/UV/TiO2 treatment has been proposed for the elimination of cypermethrin, malathion and 71 dichlorovos, by means of which 83% degradation percentage was obtained for cypermethrin [8,31].

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In addition, a wide variety of common pesticides such as bromoxynil, diuron, o-phenylphenol,

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MCPA and terbuthylazine have been mineralized through heterogeneous photocatalysis using B-

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In the present research the photocatalytic degradation of Cypermethrin was evaluated using Fe-

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(2)), which derived assuming a direct transition between the edge of the valence band and 215 conduction.
Where hν is the photon energy, α is the absorption coefficient and A is an energy dependent 217 constant and known as the band tailing parameter. Another constant is n, which is known as power      . Additionally, From BET data, the particle size, D (nm) was 246 estimated using Equation (3) [56], assuming a spherical shape for particles, where SBET refers to BET 247 surface area (m 2 /g) and ρ refers to density of samples (g/cm 3 ) and Vpore is single point adsorption total 248 pore volume of pores less than 2069,006 Å radius at P/P0= 0,995.