Production of Methanol as a Fuel Energy from CO2 Present in Polluted Seawater - A Photocatalytic Outlook

The production of methanol by photocatalytic reduction of the CO2 present in the different polluted seawater systems was explored using P–25, C/TiO2, and Cu-C/TiO2 under both UV and sunlight. Both C/TiO2 and Cu-C/TiO2 were synthesized by the sonicated sol-gel method. The prepared photocatalyst demonstrated maximum efficiency when the dosage of photocatalysts was 1g/L and the doping level was 3wt% of copper. The maximum methanol yields of two observed polluted seawater systems were 2910 μmol/g and 2250 μmol/g after 5 hour illumination of UV light. However, the 5 hour natural sunlight illumination generated the yield of 990 μmol/g and 910 μmol/g of methanol. The observed results demonstrated that band gap narrowing of the photocatalyst by carbon modification and the restriction of electron-hole pair combination by copper doping both greatly enhanced the photocatalytic reduction of CO2 to methanol under both UV and natural sunlight

Hydrographic parameters and distribution of dissolved Cu, Ni, Zn and nutrients near Jeddah desalination plant

The development of safe desalination plants with low environmental impact is as important an issue as the supply of drinking water. The desalination plant in Jeddah (Saudi Arabia, Red Sea coast) produces freshwater from seawater by multi-stage flash distillation (MSFD) and reverse osmosis (RO). The process produces brine as by-product, which is dumped into the sea. The aim of this study was to assess the impact of Jeddah desalination plant on the coastal water in the nearby of the plant. Total concentrations of dissolved Cu, Ni, Zn and nutrients in several locations around the plant were analyzed by cathodic stripping voltammetry. The average levels of dissolved Cu, Ni, and Zn on surface in the sampling locations were 15.02, 11.02, and 68.03 nM respectively, whereas the levels at the seafloor near the discharging point were much higher. Distribution of temperature, salinity, nutrients and dissolved oxygen were quite normal both on surface and in depth

Green Synthesis of TiO₂ Nanoparticles Using Natural Marine Extracts for Antifouling Activity

Titanium dioxide (TiO2) nanoparticles were synthesized via a novel eco-friendly green chemistry approach using marine natural extracts of two red algae (Bostrychia tenella and Laurencia obtusa), a green alga (Halimeda tuna), and a brown alga (Sargassum filipendula) along with a marine sponge sample identified as Carteriospongia foliascens. X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis, X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the crystal structure, surface morphology, and optical properties of the synthesized nanoparticles. Each of the as-synthesized marine extract based TiO2 nanoparticles was individually incorporated as an antifouling agent to form a newly fabricated marine paint formulation. The newly prepared formulations were applied on unprimed steel panels. A comparative study with a commercial antifouling paint (Sipes Transocean Coatings Optima) was carried out. After 108 days of the coated steel panels’ immersion in the Eastern Harbour seawater of Alexandria-Egypt, the prepared paints using B. tenella and C. foliascens extracts demonstrated an excellent antifouling performance toward fouling organisms by inhibiting their settlement and controlling their adhesion onto the immersed panels. In contrast, heavy fouling with barnacles was observed on the surface of the coated panel with the commercial paint. The physicochemical parameters of the seawater surrounding the immersed coated panels were estimated to investigate the influence of the fabricated paint formulations. Interestingly, no effects of the immersed coated panels on the physicochemical characteristics of the surrounding seawater were observed. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents, which could be attributed to the small crystallite sizes of 22.86 and 8.3 nm, respectively, in addition to the incorporation of carbon in the crystal structure of the nanoparticles

Green Synthesis of TiO2 Nanoparticles Using Natural Marine Extracts for Antifouling Activity

Titanium dioxide (TiO2) nanoparticles were synthesized via a novel eco-friendly green chemistry approach using marine natural extracts of two red algae (Bostrychia tenella and Laurencia obtusa), a green alga (Halimeda tuna), and a brown alga (Sargassum filipendula) along with a marine sponge sample identified as Carteriospongia foliascens. X-ray diffraction (XRD), scanning electron microscope (SEM), UV–Vis, X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were employed to characterize the crystal structure, surface morphology, and optical properties of the synthesized nanoparticles. Each of the as-synthesized marine extract based TiO2 nanoparticles was individually incorporated as an antifouling agent to form a newly fabricated marine paint formulation. The newly prepared formulations were applied on unprimed steel panels. A comparative study with a commercial antifouling paint (Sipes Transocean Coatings Optima) was carried out. After 108 days of the coated steel panels’ immersion in the Eastern Harbour seawater of Alexandria-Egypt, the prepared paints using B. tenella and C. foliascens extracts demonstrated an excellent antifouling performance toward fouling organisms by inhibiting their settlement and controlling their adhesion onto the immersed panels. In contrast, heavy fouling with barnacles was observed on the surface of the coated panel with the commercial paint. The physicochemical parameters of the seawater surrounding the immersed coated panels were estimated to investigate the influence of the fabricated paint formulations. Interestingly, no effects of the immersed coated panels on the physicochemical characteristics of the surrounding seawater were observed. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents. Based on the obtained results and a comparison with commercially available antifouling products, the marine extract based TiO2 nanoparticle preparations of B. tenella and C. foliascens are promising candidates for eco-friendly antifouling agents, which could be attributed to the small crystallite sizes of 22.86 and 8.3 nm, respectively, in addition to the incorporation of carbon in the crystal structure of the nanoparticles

Environmental impact assessment of desalination plants through observations and modeling over Central Red Sea-Yanbu and Rabiq

Desalination remains in Saudi Arabia the supreme viable alternative to boost the future water supply requirements. The present research is focused on the environmental issue observations and modeling based on dissolved trace metals, hydrographic parameters, and nutrients at the discharging plume and nearby locations of Rabig desalination plant (RDP) and Yanbu desalination plant (YDP) located at the north of Jeddah city (~ 150 and 400 km, respectively). A multi-effect distillation (MED) technology is used in RDP whereas, in YDP, a combination of multistage flashing (MSF), reverse osmosis (RO), and MED technologies is in use for the production of potable waters. The concentration of dissolved Cu, Ni, and Zn was assessed by using cathodic stripping voltammetry. The observed pattern was reflecting an average value of dissolved Cu, Ni, and Zn at RDP that was 8.24, 5.28, and 12.69 nM, respectively. The correspondent changes at YDP were 17.53, 18.06, and 71.19 nM of Cu, Ni, and Zn, respectively. The statistical validation shows a significant positive correlation between metals and temperature with salinity and a significant negative correlation of dissolved oxygen and pH. The background concentration of nearby YDP is comparatively higher and which is ascribed by the negative effects of nearby industries. Detailed investigation of circulation pattern and brine discharge analysis near the Yanbu desalination plant also carried out with the help of 3d hydrodynamical numerical model Delft3d

Cytotoxic scalarane-type sesterterpenes from the Saudi Red Sea sponge <i>Hyrtios erectus</i>

<p>The CHCl₃/MeOH extract of the marine sponge <i>Hyrtios erectus</i> showed cytotoxicity against three cancer cell lines HepG2, A549, and PC-3 with IC₅₀ 0.055, 0.044, and 0.023 μg/ml, respectively. The CH₂Cl₂ soluble fraction afforded three scalarane sesterterpenes (<b>1–3</b>) along with a cholestane derivative (<b>4</b>) and an indole alkaloid (<b>5</b>). Chemical structures were established by spectroscopic techniques and comparison with data reported in the literature. Scalarinol (<b>1</b>) was found as a new metabolite, while heteronemin (<b>2</b>) and 12-<i>O</i>-deacetyl-19-deoxyscalarin (<b>3</b>) are known compounds. <b>1–3</b> exhibited cytotoxic activity against the cancer cell lines with IC₅₀ values ranging from 14 to 230 μM. The molecular affinity to the DNA was employed as marker to examine the proposed mechanism of cytotoxic activities. Compound <b>2</b>, with IC₅₀ 28 μg/ml, displayed the highest affinity to the DNA.</p

DataSheet1_Fabrication and assessment of potent anticancer nanoconjugates from chitosan nanoparticles, curcumin, and eugenol.PDF

In cancer management and control, the most challenging difficulties are the complications resulting from customized therapies. The constitution of bioactive anticancer nanoconjugates from natural derivatives, e.g., chitosan (Ct), curcumin (Cur), and eugenol (Eug), was investigated for potential alternatives to cancer cells’ treatment. Ct was extracted from Erugosquilla massavensis (mantis shrimp); then, Ct nanoparticles (NCt) was fabricated and loaded with Cur and/or Eug using crosslinking emulsion/ionic-gelation protocol and evaluated as anticancer composites against CaCo2 “colorectal adenocarcinoma” and MCF7 “breast adenocarcinoma” cells. Ct had 42.6 kDa molecular weight and 90.7% deacetylation percentage. The conjugation of fabricated molecules/composites and their interactions were validated via infrared analysis. The generated nanoparticles (NCt, NCt/Cur, NCt/Eug, and NCt/Cur/Eug composites) had mean particle size diameters of 268.5, 314.9, 296.4, and 364.7 nm, respectively; the entire nanoparticles carried positive charges nearby ≥30 mV. The scanning imaging of synthesized nanoconjugates (NCt/Cur, NCt/Eug, and NCt/Cur/Eug) emphasized their homogenous distributions and spherical shapes. The cytotoxic assessments of composited nanoconjugates using the MTT assay, toward CaCo2 and MCF7 cells, revealed elevated anti-proliferative and dose-dependent activities of all nanocomposites against treated cells. The combined nanocomposites (NCt/Eug/Cur) emphasized the highest activity against CaCo2 cells (IC50 = 11.13 μg/ml), followed by Cur/Eug then NCt/Cur. The exposure of CaCo2 cells to the nanocomposites exhibited serious DNA damages and fragmentation in exposed cancerous cells using the comet assay; the NCt/Eug/Cur nanocomposite was the most forceful with 9.54 nm tail length and 77.94 tail moment. The anticancer effectuality of innovatively combined NCt/Cur/Eug nanocomposites is greatly recommended for such biosafe, natural, biocompatible, and powerful anticancer materials, especially for combating colorectal adenocarcinoma cells, with elevated applicability, efficiency, and biosafety.</p