Inhibitory Capabilities of Sweet Yellow Capsicum Extract toward the Rusting of Steel Rebars in Cement Pore Solution.

The inhibitory capabilities of the sweet yellow capsicum extract (SYCE) toward the rusting of steel rebars in cement pore solution (CPS) were tested employing the electrochemical and mass loss methods. Gallic acid, caffeic acid, p-coumaric acid, ferulic acid, luteolin, and cinnamic acid are the most important constituents in the SYCE extract. By adsorbing them on steel bars, the organic compounds in the CSA extract enable them with an effective mixed-type inhibition, suppressing both anodic and cathodic procedures. At 300 ppm, the highest performances were 95.3 and 97.5% utilizing mass loss and electrochemical approaches, respectively. The activation energy for the corrosion process is greatly increased by the addition of the SYCE extract, going from 13.2 kJ mol-1 (blank solution) to 30.0 kJ mol-1 (300 ppm SYCE extract). The physical adsorption actions of the SYCE extract are described by the Freundlich equilibrium constant's smallest value, which is 0.074 ppm-1. Many future investigators will be attracted by these discoveries to work relentlessly to uncover the anti-corrosion characteristics of novel plant extracts in the area of concrete additives.

Bioadsorption of Fe (II) ions from aqueous solution using Sargassum latifolium aqueous extract and its synthesized silver nanoparticles.

Algal extracts are used in the environmentally safe and economically advantageous biosynthesis of silver nanoparticles, which does not require the use of hazardous chemicals, high temperatures, pressures, or energies. In the current study, we created silver nanoparticles from the extract of the marine brown alga Sargassum latifolium, analyzed them with Transmission Electron Microscopy (TEM), FTIR, and UV-visible spectrophotometers, and used them to show how well they could remove Fe (II) ions from aqueous solutions. UV scan analyses of S. latifolium aqueous extract of silver nanoparticles showed a maximum peak at 450 nm. This peak is considered a characteristic peak for silver nanoparticles. Also, FTIR analysis of S. latifolium aqueous extract revealed various functional groups such as - OH, -NH, -CH, -COOH, CO, and C-C, which are responsible for bioadsorption of Fe (II). TEM also demonstrated that the synthesized nanoparticles were spherical, distinct, and regular, with particles size about 6.03-15.16 nm. S. latifolium aqueous extract silver nanoparticles were more effective than its aqueous extract in removing Fe (II) from an aqueous solution. The removal efficiency of Fe (II) by nanoparticles was 83%, while by the aqueous extract was 69%. The optimal conditions for bioadsorption of Fe (II) were pH 4, contact time 150, and adsorbent dose 0.01 g.

No work has been reported yet for utilization of marine brown algae Sargassum latifolium aqueous extract to synthesize silver nanoparticles and its application of Fe (II) bioadsorption from aqueous solution.

Impact of the microalga Dunaliella salina (Dunal) Teodoresco culture and its ß-carotene extract on the development of salt-stressed squash (Cucurbita pepo L. cv. Mabrouka).

Salinity is a major threat to crop production and global food security. Algae and their extracts containing bioactive compounds can enhance the salt tolerance of plants, including the salt-sensitive plants. The current study evaluated the efficacy of Dunaliella salina (Dunal) Teodoresco culture and/or its ß-carotene extract in improving the salt tolerance of squash (Cucurbita pepo L. cv. Mabrouka). Amendment of C. pepo with D. salina culture and/or its ß-carotene extract was more effective in alleviating the impact of moderate salinity imposed by seawater dilution of 2.5 dS m-1 than either low (0.55 dS m-1) or high (3.5 dS m-1) salinity, with a comparable effect to that of salicylic acid (SA). Plants that received a combination of D. salina culture and its ß-carotene extract showed significantly higher growth (total biomass, fruit productivity) and physiological attributes (photosynthetic pigments, nitrogen (N), phosphorus (P), and potassium (K+) contents) than those receiving either amendment alone, reaching up to 80-90% of the SA-treated plants at moderate salinity (2.5 dS m-1). The combination could enhance the antioxidant activity of moderately salt-stressed C. pepo via increasing carotenoids and phenolics contents, suggesting that this combination could enhance the adaptation of C. pepo to the moderate salinity. The present study recommends using the blooms of D. salina and its ß-carotene that is naturally secreted in situ in natural or synthetic open systems in improving the salt tolerance of C. pepo instead of using the expensive synthetic hormones. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01176-6.