Phyco-Synthesized Zinc Oxide Nanoparticles Using Marine Macroalgae, Ulva fasciata Delile, Characterization, Antibacterial Activity, Photocatalysis, and Tanning Wastewater Treatment

Abstract

The aqueous extract of marine green macroalgae, Ulva fasciata Delile, was harnessed for the synthesis of zinc oxide nanoparticles (ZnO-NPs). The conversion to ZnO-NPs was characterized by color change, UV–vis spectroscopy, FT-IR, TEM, SEM-EDX, and XRD. Data showed the formation of spherical and crystalline ZnO-NPs with a size range of 3–33 nm. SEM-EDX revealed the presence of Zn and O in weight percentages of 45.3 and 31.62%, respectively. The phyco-synthesized ZnO-NPs exhibited an effective antibacterial activity against the pathogenic Gram-positive and Gram-negative bacteria. The bacterial clear zones ranged from 21.7 ± 0.6 to 14.7 ± 0.6 mm with MIC values of 50–6.25 µg mL−1. The catalytic activity of our product was investigated in dark and visible light conditions, using the methylene blue (MB) dye. The maximum dye removal (84.9 ± 1.2%) was achieved after 140 min in the presence of 1.0 mg mL−1 of our nanocatalyst under the visible light at a pH of 7 and a temperature of 35 °C. This percentage was decreased to 53.4 ± 0.7% under the dark conditions. This nanocatalyst showed a high reusability with a decreasing percentage of ~5.2% after six successive cycles. Under the optimum conditions, ZnO-NPs showed a high efficacy in decolorizing the tanning wastewater with a percentage of 96.1 ± 1.7%. Moreover, the parameters of the COD, BOD, TSS, and conductivity were decreased with percentages of 88.8, 88.5, 96.9, and 91.5%, respectively. Moreover, nano-ZnO had a high efficacy in decreasing the content of the tanning wastewater Cr (VI) from 864.3 ± 5.8 to 57.3 ± 4.1 mg L−1 with a removal percentage of 93.4%.

Green Synthesis of Silver Nanoparticles Using Salvia verticillata and Filipendula ulmaria Extracts: Optimization of Synthesis, Biological Activities, and Catalytic Properties

“…The “greening” of this process led to the cessation of the use of large quantities of harmful organic substances, an increase in efficiency, a reduction in toxicity and eco-toxicity, and a reduction in the process price in comparison to previous physical and chemical methodologies [ 2 , 6 ]. Great success in the synthesis of metal and metal oxide nanoparticles that exhibited different biological and catalytic activities, such as silver, ZnO and MgO nanoparticles, was achieved using plant extracts, marine macroalgae ( Ulva fasciata Delile), bacteria Pseudomonas aeruginosa , and brown algae ( Cystoseira crinita ) [ 7 , 8 , 9 , 10 ].…”

Heavy Metals Removal by Using Chlorella Vulgaris Microalgae/ Zinc Oxide Nanocomposite for Wastewater Treatment in Menyet El-Nasr, Egypt

“…Transmission electron microscopy confirmed the presence of gold nanoparticles produced intracellularly by Cholera vulgaris, as described by Luangpipat et al (16) . The Size, aggregation, shape, surface charge, and stability are only few of the factors that affect a nanoparticle's activity (17) . Therefore, it is essential to determine the morphological characteristics, especially the size, shape, and aggregation of the synthesized nanocomposite.…”

Algal Extracts for Green Synthesis of Zinc Oxide Nanoparticles: Promising Approach for Algae Bioremediation

“…Also, the review emphasizes the potential applications of green-synthesized ZnO-NPs in various fields, including wastewater treatment [ 31 ]. The study by Fouda et al [ 32 ] explored the potential of using Ulva fasciata in the green synthesis of ZnO-NPs. The results indicated that the algae extract could successfully reduce zinc ions to ZnO-NPs in a fast and eco-friendly manner.…”

“…Moreover, the ZnO-NPs were found to exhibit good photocatalytic activity towards the degradation of methylene blue, and they were also able to remove Cr(VI) ions from tanning wastewater. The study concluded that Ulva fasciata Delile extract could be a promising and sustainable source for the green synthesis of ZnO-NPs with potential applications in various fields, including antibacterial and photocatalytic activities and tanning-wastewater treatment [ 32 ].…”