Review: Silica Aerogel as a Viable Absorbent for Oil Spill Remediation

The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review presents the various dynamics of oil spill, conventional clean-up technologies and sili- ca aerogel synthesis techniques. It also highlights some investigations of oil spill sorption using aerogels. The future prospect of rice husk as a cheaper source silica aerogel is also considere

Biosynthesis, Characterization and Biological Applications of Silver Nanoparticles using Celosia trigyna and Solanum nigrum Extracts: Neglected Vegetables in Nigeria

Plant-mediated synthesis is gaining acceptance in many fields i.e. biology and pharmaceutical fields. This aim of this study is synthesizing Ag nanoparticles using air-dried leaves of two (2) neglected vegetables i.e.  Celosia trigyna and Solanum nigrum.  Ultraviolet–visible spectroscopy, fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize the formation of silver nanoparticles (AgNPs). The anti-inflammatory properties of these AgNPs were evaluated using Cell Stabilization Membrane (CSM) and lipoxidase assays, their antioxidant activity were established on DPPH and ABTS+ assays. The positive control employed are indomethacin and ascorbic acid for these activities. Nanoparticles synthesized were labelled for Celosia trigyna (CT-AgNPs) and Solanum nigrum (SN-AgNPs) were noticed through visual color change. The UV–Vis spectra of the synthesized nanoparticles displayed absorption bands at around 360-440 nm, which is a characteristic band for Ag and FTIR displayed possible functional groups responsible for Ag nanoparticles synthesized by these plants.  The SEM image of the AgNPs formed displayed were spherical in morphology. CT-AgNPs exhibited the most significant inhibitory activity against HRBC (IC50: 32.2 µg/ml) while SN-AgNPs displayed the most significant inhibitory activity against lipoxygenases (IC50: 32.8 µg/ml) when compared to the positive control used indomethacin (IC50: 28.1 µg/ml). SN-AgNPs exhibited the most significant antioxidant effect against ABTS (IC50: 11.4 µg/ml) while CT-AgNPs displayed the most significant antioxidant activity against DPPH (IC50: 4.6 µg/ml) when compared to the positive control used ascorbic acid (IC50: 4.7 µg/ml). This work showed that the synthesized AgNPs from non-cultivated vegetable can find relevance and application in health, drugs, food and environmental science

Preparation and Characterization of Modified Adsorbents Derived from Pawpaw (Carica papaya) Leaf

The feasibility of a new and novel adsorbent was investigated by impregnation of pawpaw leaf (Carica papaya) in H2SO4 and NaOH respectively. The adsorbents prepared were characterized using FTIR, SEM, TGA and EDX techniques respectively. Physicochemical parameters of these adsorbents such as pH, moisture content, ash content, porosity and iodine number were also carried out; the results were then compared with the expensive commercial activated carbon (CAC) parameters. A close agreement in moisture, pH, porosity, ash content and iodine number of the acid activated pawpaw leaf (Carica papaya) shows its feasibility as a good and effective adsorbent. Conclusively, the present investigation shows that acid activated C. papaya leaf is a good and viable alternative adsorbent, which could be used in lieu of expensive CAC for adsorption processes

Mechanism and Isotherm Modeling of Effective Adsorption of Malachite Green as Endocrine Disruptive Dye using Acid Functionalized Maize Cob (AFMC)

Cationic Malachite green has been identified as a candidate of endocrine disruptive compound found in the environment. In this study, the mechanism and isotherm modeling of effective adsorption of cationic malachite green dye onto acid functionalized maize cob (AFMC) was investigated by batch technique. The operational parameters such as initial concentration (100 – 600 mg/L); contact time (10 – 120 mins) and pH (3 – 10) influenced the removal efficiency and quantity adsorbed. Maximum of 99.3% removal efficiency was obtained at optimum conditions. AFMC physicochemical properties (surface area 1329 m2 /g and particle size 300μm0.97 and consistently low values of SSE, X2, HYBRID and MSPD adsorption statistical error functions (ASEF), equilibrium data were best fitted to Freundlich isotherm. Kinetic data were best described by pseudo second-order model with consistent R2 >0.98 and validated by ASEF. The mechanism of process was better described by intraparticle diffusion. Evidence of adsorption process was confirmed by change in morphology and surface chemistry determined by SEM and FTIR respectively. The performance of AFMC enlisted it as a sustainable and promising low-cost adsorbent from agro-residue for treatment of endocrine disruptive dye polluted water

Silver nanoparticle synthesis by Acalypha wilkesiana extract: phytochemical screening, characterization, influence of operational parameters, and preliminary antibacterial testing

© 2019, The Author(s). Introduction: The application of skin bleaching products to inhibit melanogenesis is a common practice within the African diaspora. Despite the adverse health effects of skin bleaching, rigorous studies investigating skin bleaching behavior among these populations in the United States are limited. In our P30 pilot study, we explored predictors of skin bleaching practice intensity among African and Afro-Caribbean women. Methods: In collaboration with our Community Engagement Core, we conducted a cross-sectional study to investigate the relationship between demographic and psychosocial predictors and skin-bleaching-related practice patterns among African and Afro-Caribbean women in New York City. Results: Among the 76 participants recruited, the median age at the initiation of skin bleaching was 19.5 (16–25) years, yielding a median duration of 13.5 (6–23) years. Although pregnant women were not actively recruited for the study, 13.2% (n = 10) of the participants used skin bleaching products while pregnant or possibly breastfeeding. Nativeness and education were associated with various components of skin bleaching practice intensity, including duration of skin bleaching, daily use of products, and bleaching of the entire body. Participants’ perceived skin-color-related quality of life was not associated with skin bleaching practice intensity. Conclusion: Skin bleaching is a habitual practice that likely requires culturally sensitive interventions to promote behavioral change. The existence of prenatal and postnatal exposure to mercury, hydroquinone, and other potentially harmful chemicals in skin bleaching products highlights an urgent need to explore the adverse effects of skin bleaching practices on birth outcomes and the growth and neurodevelopment of young babies

In Vivo Antiplasmodial Potential of the Leaf, Mesocarp, and Epicarp of the Raphia hookeri Plant in Mice Infected with Plasmodium berghei NK65

Background of the study. Raphia hookeri G. Mann & H. Wendl (Arecaceae) is an important plant used in folkloric medicine to treat various ailments such as inflammation, tumor, microbial infections, paralysis, hypertension, and rheumatism, primarily in Africa and Asia. Aim and Objectives. The study was designed to investigate the antiplasmodial and antioxidant potencies of Raphia hookeri leaves, mesocarp, and epicarp using Plasmodium infected mice. The bioactive constituents were further explored via gas chromatography-mass spectrometry (GC-MS). Results. The presence of alkaloids, fats and oils, phenolic, and flavonoids was detected via the qualitative test which was confirmed from the result obtained from the GC-MS chromatogram of ethanolic leaves extract. The GC-MS chromatogram of the constituents analogous to the twenty peaks was analyzed as follows: dodecanoic acid (1.94%), 2-undecanone (3.42%), hexadecanoic acid (44.84%), oleic acid (7.45%), octadecanoic acid (8.41%), narcissidine (2.38%), 1-dotriacontanol (2.38%), α-sitosterol (2.02%), and lupeol (1.42%). The total phenolics and flavonoids of 118 and 23.3702 mg/g were analyzed in the leaves extract. The leave extract exhibited inhibitory activity of 73.49% against free radicals which could lead to inflammation. The extracts and chloroquine-treated groups showed significant decrease in percentage parasitaemia with pronounced activity observed in chloroquine groups. Conclusion. The curative and scavenging potencies of studied plant could be attributed to the metabolites analyzed and could guide the formulation of new pharmacophores against malaria infections and inflammations

Examining Rational Bubbles in Oil Prices: Evidence From Frequency Domain Estimates

This study examined the existence of rational bubbles in oil prices by employing a frequency domain econophysics technique that have capacity to identify both explosive behaviour and bubbles in oil prices for the three largest oil future markets – WTI, Brent and OPEC basket. Our results show that the three prices experienced bubbles in four distinct periods. We attempt to provide some explanations on each of these bubbles using geopolitical, war and economic events. We equally noted that oil prices bubbles are largely influenced by the fact that oil is a major source of energy and is non-renewable. The study observed that existence of bubbles have some economic consequences such as welfare loss resulting from distortion in prices and economic instability among others. We provide some policy recommendation. Keywords: oil prices, rational bubbles, energy JEL Classifications: C22, C50, G10, G12 DOI: https://doi.org/10.32479/ijeep.746

Preparation and Characterization of Biochar and Activated Carbon Derived from Cashew Bagasse Waste

Biochar and Activated carbon derived from cashew bagasse waste are veritable materials produced from agro-waste. They are currently under-utilized owing to paucity of information in their recycling methods which reduces agricultural waste from the environment. This study investigates the use of under-utilized cashew bagasse waste in the production of biochar and activated carbon using pyrolysis and chemical activation methods, respectively. Cashew bagasse waste was pyrolysed at 4000C for 20mins at a heating rate of 100C per mins. The biochar produced was allowed to cool at room temperature for 30 mins. It was further reduced to smaller size particles using euro premium grinder and later sieved with 10 mesh sieve size prior to its application. The biochar was chemically activated using 0.3M Orthophosphoric acid (H3PO4) as activating agent at an impregnation ratio of 1:2.36(w/w). It was heated at 1000C to form a paste and later placed in muffle furnace at 5000C for 30 mins. This was allowed to cool and washed with distilled water until a neutral pH was obtained and later oven dried at 1050C for 24 hours to a constant weight to produce activated carbon. The produced activated carbon was kept in air tight containers prior to analysis. Characterization of pH, bulk density, moisture content, dry matter, volatile matter, and fixed carbon were determined for biochar and activated carbon. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analysis was performed to determine the functional groups and surface morphology of biochar and activated carbon, respectively. The Data obtained were analyzed using descriptive statistics and ANOVA at P value < 0.05. The results showed that significant differences (p<0.05) were observed in the characterized parameters determined. The biochar and activated carbon has pH: (7.68±0.06 and 6.13±0.03); Bulk density :( 0.18±0.01 and 0.20±0.01) %; Moisture content: (6.67±0.33 and 16.00±0.58)%; Dry matter (93.33±0.33 and 84.00±0.58) %; Volatile matter (68.67±3.18 and 29.67±5.21) %; Fixed carbon (30.24±3.20 and 69.32±5.16) %, respectively. FTIR Analysis showed that biochar and activated carbon were more polar and also contained specific bonds. SEM analysis also indicated that biochar and activated carbon have porous structures. This study, therefore, revealed that chemically activated carbon had better characteristics than biochar produced through pyrolysis method

Formaldehyde free particleboards from wood chip wastes using glutaraldehyde modified cassava starch as binder

The study determined some physical and mechanical properties of particleboards produced from wood chip wastes and modified cassava starch (MCS). The native cassava starch was modified with 25% glutardialdehyde solution. Density, water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE) and modulus of rupture (MOR) were evaluated based on Japanese Industrial Standard (JIS). Scanning electron microscope (SEM) Fourier-transform infrared spectroscopy (FTIR) were utilised to conduct the microstructural and elemental analyses of the particleboards. Density ranged from 0.21 to 0.54 g/cm3 , WA ranged from 32.7 to 168.9% after 2 and 24 h immersion while TS ranged from 1.8 to 67.9% after 2 and 24 h immersion. Peak values at 3232.0 N/mm2 and 35.7 N/mm2 for MOE and MOR were recorded for the MCS bonded boards. SEM showed well-dispersed MCS granules on the surface of the particleboards while FTIR indicated the occurrence of aldehyde and ester forms attributed to MCS binder. The modified cassava starch bonded boards showed good prospects for utilization in non-load applications having displayed a better performance than the unmodified particleboards