The Impact of Corrosion Inhibitors in Desalination Systems.

In this review, the importance of corrosion inhibitors in desalination plants is briefly discussed, with an emphasis on the various types for effective corrosion control techniques. The review highlighted the most significant corrosion inhibitors used in desalination plants for minimizing the corrosiveness of the source water throughout pretreatment, reverse osmosis, and post-treatment stages. Water composition, temperature and pressure, pH, dissolved oxygen, flow velocity, chloride content, fouling, and scaling are all described as factors affecting corrosion in desalinated water. The types of corrosion inhibitors used in desalination plants are summarized, including inorganic inhibitors, organic inhibitors, and eco-friendly inhibitors. Environmental issues and long-term inhibition are highlighted briefly.

Chemical Composition, Antioxidant, and Antitumor Activity of Fucoidan from the Brown Alga Dictyota dichotoma.

Brown macroalgae are a rich source of fucoidans with many pharmacological uses. This research aimed to isolate and characterize fucoidan from Dictyota dichotoma var. dichotoma (Hudson) J.V. Lamouroux and evaluate in vitro its antioxidant and antitumor potential. The fucoidan yield was 0.057 g/g algal dry wt with a molecular weight of about 48.6 kDa. In terms of fucoidan composition, the sulfate, uronic acid, and protein contents were 83.3 ± 5.20 mg/g fucoidan, 22.5 ± 0.80 mg/g fucoidan, and 26.1 ± 1.70 mg/g fucoidan, respectively. Fucose was the primary sugar component, as were glucose, galactose, mannose, xylose, and glucuronic acid. Fucoidan exhibited strong antioxidant potential that increased by more than 3 times with the increase in concentration from 0.1 to 5.0 mg/mL. Moreover, different concentrations of fucoidan (0.05-1 mg/mL) showed their ability to decrease the viability of Ehrlich ascites carcinoma cells in a time-dependent manner. These findings provided a fast method to obtain an appreciable amount of natural fucoidan with established structural characteristics as a promising compound with pronounced antioxidant and anticancer activity.

Bioremediation of malachite green dye using sodium alginate, Sargassum latifolium extract, and their silver nanoparticles.

INTRODUCTION: The textile, paper, rubber, plastic, leather, cosmetics, pharmaceutical, and food sectors extensively use malachite green (MG). In spite of this, it has mutagenic, carcinogenic, teratogenic, and, in some circumstances causes chronic respiratory disease. OBJECTIVES: In this work, we used sodium alginate, Sargassum latifolium aqueous extract, and their silver nanoparticles to test their potential as inexpensive adsorbent agents to remove malachite green dye from aqueous solutions. METHODS: The removal rate of MG was determined using a series of bioadsorption experiments. Besides, the effect of different factors on bioadsorption, such as pH, adsorbent dose, contact time (min), and different concentrations of MG dye was investigated. RESULTS: The removal efficiency of MG dye by alginate nanoparticles, alginate, Sargassum latifolium aqueous extract, and S. latifolium aqueous extract nanoparticles was 91, 82, 84, and 68 respectively. The optimal conditions for bioadsorption of malachite green dye were pH 7, a contact time of 180 min, and an adsorbent dose of 0.02 g. The adsorption isotherm was fitted to Langmuir and Freundlich isotherm. Also, UV and FT-IR before and after the bioadsorption of MG were performed to confirm the bioadsorption process. CONCLUSION: Our results indicated that alginate nanoparticles were the most effective bioadsorbent agent.

Controlling the Hydrogen Generation Reaction from Waste Water in Oil Fields Using an Ionic Liquid.

Hydrogen production technologies are attracting widespread interest in energy technologies. The conventional methods for hydrogen production suffer from high cost, restricting their production everywhere. Here, we use waste formation water from a petroleum field and carbon steel materials to produce hydrogen. The most suitable conditions have been investigated to maximize the hydrogen yield. In addition, an ionic liquid (i.e., tributylmethylammonium methyl carbonate, BMAMC) has been used to control the hydrogen generation reaction. We reveal that the amount of hydrogen release rapidly increases with decreasing pH of the solution from 6.7 to 2.5. A further increase in temperature resulted in more amount of hydrogen release. Our study investigates the influence of chloride ions on hydrogen generation activity. The results revealed that ionic liquid BMAMC remarkably decreases the amount of hydrogen release with an efficiency of 92% at 5.08 × 10-4 M. The addition of ionic liquid BMAMC into waste formation water increases the activation energy of the hydrogen generation reaction. The Langmuir model is the best isotherm describing the adsorption of BMAMC on carbon steel. Finally, to confirm the adsorption of the ionic liquid BMAMC, scanning electron microscopy and Fourier-transform infrared spectroscopy analysis were conducted.

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.

Green Synthesis of a Novel Cationic Surfactant Based on an Azo Schiff Compound for Use as a Carbon Steel Anticorrosion Agent.

The new cationic surfactant-based azo Schiff compound (azoS8) was prepared, characterized, and investigated as a corrosion inhibitor for carbon steel in 1 M HCl by means of electrochemical approaches in this study. The chemical structure of azoS8 has been verified by the FTIR and 1H NMR spectra. According to the electrochemical system, the examined surfactant is a mixed-type inhibitor. The surfactant azoS8 was an adequate corrosion inhibitor, as evidenced by the reduction in corrosion current densities and the rise in coverage of the surface identified with an evolving inhibitor amount. When the surfactant azoS8 had been added, the capacitive cycle loops on the Nyquist plots were broader, and the dimension of these loops expanded with surfactant azoS8 concentration. This implies that the amount of surfactant azoS8 led to an improvement in the impedance of the steel electrode. The surfactant azoS8 adsorption system is well suited to the Langmuir adsorption isotherm. It was discovered that azoS8 had a Gibbs free energy change value of -27.72 kJ mol-1, which is a mixed adsorption mechanism containing both physisorption and chemisorption.

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.

Biological control of Fusarium tomato-wilt disease by cyanobacteria Nostoc spp.

This study investigated the effect of foliar application of extract and culture of Nostoc calcicola and Nostoc linckia on the Fusarium oxysporum f. sp. lycopersici (FOL) that infects tomatoes (Solanum lycopersicum) plant in vitro and in vivo. Cyanobacterial isolates were isolated from saline soils at El-Hamoul and Seidy Salem locations Kafr Elsheikh, Egypt, and identified to be N. calcicola and N. linckia Bioactive compounds of extract were analyzed by Gas chromatography-mass spectrometry (GC-MS). Dry weight, carotene, chlorophyll content, and total phenolic compounds of isolates were measured. Plant height, dry weight, fruit number, and fruit weight of tomatoes were estimated. GC/MS analysis showed 49 and 35 bioactive compounds in extracts of N. calcicola and N. linckia, respectively. N. calcicola possesses the highest values of chlorophyll a, carotenoid, and total phenol contents in dry weight compared with N. linckia. After 100 days of tomato growth, the results showed the highest yield of tomato fruits with the application of N. calcicola and N. linckia compared with the untreated plants and the plants which were infected with Fusarium, suggesting that N. calcicola and N. linckia can serve as a new bioagent for biological control of the soil fungus Fusarium oxysporum f. sp. lycopersici (FOL).

Impact of Ionic Liquid on Hydrogen Production from Waste Oilfield Water.

We present a promising method for producing pure hydrogen energy from the dissolution of zinc metal in waste oilfield water (WOW) under various conditions. This process mainly consumes zinc metal and WOW. The results show robust dependence on the temperature and solution pH of the hydrogen gas output. Low pH (2.5) and high temperature (338 K) were discovered to be the better conditions for hydrogen production. The 1-ethyl-3-methylpyridinium ethyl sulfate (EMP-ES) ionic liquid is used to regulate the rate of hydrogen generation for the first time. It has been confirmed that the rate of the dissolution of zinc increased faster and produced more hydrogen per unit of time by an increase in solution temperature and a decrease in solution pH. The adsorption of EMP-ES on the active sites of the Zn surface is unrestrained with mixing physical and chemical orientations. SEM, EDX, and FTIR spectroscopy inspections have been utilized to identify and characterize surface corrosion of zinc in WOW. Furthermore, this process is completely secure and can generate energy on demand.

Controlling Magnesium Self-Corrosion in Mg-Air Batteries with the Conductive Nanocomposite PANI@3D-FCNT.

A promising potential device for storage of large amounts of energy is Mg-air batteries. However, the corrosion of the Mg electrode inside the battery electrolyte limits the battery's capacity to store energy. We present a new strategy to protect the Mg electrode from corrosion and increase the life cycle of Mg batteries in this article. The Mg electrode is coated with a conductive nanocomposite (PANI@3D-FCNT) in this technique. To better understand the anticorrosion properties of PANI@3D-FCNTs and their effect on the battery efficiency, electrochemical and battery tests are used. We discovered that PANI@3D-FCNT plays the most promising role in reducing Mg electrode corrosion in 3.5 wt % NaCl electrolyte, with an efficiency of 93.9%. The battery with the coated Mg electrode has a longer discharge time and a slower drop in operating voltage. The PANI@3D-FCNT nanocomposite will prolong the life of the Mg-air battery and keep the Mg electrode active for a long time. This work outstandingly provides an effective strategy to address the defects in the Mg-air batteries arising from electrode corrosion successfully. The work is a great way to open up new avenues for introducing new conductive nanocomposites in metal-air battery designs without using traditional methods.

Coronaviruses widespread on nonliving surfaces: important questions and promising answers.

The world is facing, while writing this review, a global pandemic due to one of the types of the coronaviruses (i.e., COVID-19), which is a new virus. Among the most important reasons for the transmission of infection between humans is the presence of this virus active on the surfaces and materials. Here, we addressed important questions such as do coronaviruses remain active on the inanimate surfaces? Do the types of inanimate surfaces affect the activity of coronaviruses? What are the most suitable ingredients that used to inactivate viruses? This review article addressed many of the works that were done in the previous periods on the survival of many viruses from the coronaviruses family on various surfaces such as steel, glass, plastic, Teflon, ceramic tiles, silicon rubber and stainless steel copper alloys, Al surface, sterile sponges, surgical gloves and sterile latex. The impacts of environmental conditions such as temperature and humidity were presented and discussed. The most important active ingredients that can deactivate viruses on the surfaces were reported here. We hope that these active ingredients will have the same effect on COVID-19.