Environmental Engineering
E. Fares; B. Aissa; R.J. Isaifan
Abstract
Background and objectives: Global energy needs have gradually shifted toward photovoltaic solar energy, especially in the Gulf region because of the high solar-irradiance potential. However, one of the main challenges for this technology in the region is soiling, which has been reported to degrade the ...
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Background and objectives: Global energy needs have gradually shifted toward photovoltaic solar energy, especially in the Gulf region because of the high solar-irradiance potential. However, one of the main challenges for this technology in the region is soiling, which has been reported to degrade the power output of photovoltaic modules significantly. Anti-soiling coatings are promising technologies to minimize the effect of dust on photovoltaic solar panels. Accordingly, this study aimed to synthesize aluminum, zinc, titanium, and tin oxides using mixed-based and nanoparticle-based precursors through inkjet printing techniques and investigate their potential in anti-soiling applications for PV panels.Methods: Four metal oxides, namely, aluminum, zinc, titanium, and tin oxides, were synthesized and deposited using the inkjet printing technique for anti-soiling application. Ultraviolet-visible spectroscopy, field emission scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, and contact angle measurements were performed to characterize these thin films.Finding: The optical transmittance of the substrate using the nanoparticle ink revealed better optical properties than that using the mixed-based ink. Compared with nanoparticle samples, a homogeneous crack and a defect-free layer were observed with dense nanoparticles in all mixed inks (except for aluminum oxide ink). The contact angles indicated that the synthesized films were super-hydrophilic/hydrophilic coatings. The results of the outdoor testing revealed that up to 60% less dust was deposited on the best-performing film (aluminum oxide mixed-based ink) compared with bare glass. Conclusion: The outdoor experiment revealed that mixed-based thin films were better in reducing dust deposition than nanoparticle-based thin films and bare glass. This enhancement might be due to the decreased antireflection property along with a morphological contribution related to the presence of nanoparticle voids, which reduce the spectra scattering and minimize its deterioration, thus demonstrating better anti-soiling properties. The results of the outdoor test revealed that aluminum, zinc, and titanium oxides are promising materials for anti-soiling coating applications for both ink types. However, tin oxide coatings are not recommended for anti-soiling applications, as they showed the highest dust deposition rate near the bare glass performance.
Environmental Management
D. Tomacheski; M. Pittol; D.N. Simões; V.F. Ribeiro; R.M.C. Santana
Abstract
There is a growing consumer market for products that proclaim to decrease microorganism counts to prevent infections. Most of these products are loaded with silver in its ionic or nanoparticle form. Through use or during production, these particles can find their way into the soil and cause an impact ...
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There is a growing consumer market for products that proclaim to decrease microorganism counts to prevent infections. Most of these products are loaded with silver in its ionic or nanoparticle form. Through use or during production, these particles can find their way into the soil and cause an impact in microbial and plant communities. This study aims to evaluate the impact of silver based particles in Avena byzantina (oat), Lactuca sativa (lettuce) and Raphanus sativus (radish) development and in the soil microorganism abundance. Oat, lettuce and radish plants were cultivated in soil contaminated with particles of bentonite organomodified with silver (Ag+_bentonite), silver phosphate glass (Ag+_phosphate) and silver nanoparticles adsorbed on fumed silica (AgNp_silica). Plant development and microorganisms’ abundance were evaluated. To some degree, Ag+_bentonite impacted plants development and AgNp_silica causes an adverse effect on microbial abundance. The impact on plants and microorganisms was contradictory and varied according to soil and particles physicochemical characteristics.
