Adewale Adewuyi

Successful scale-up performance of a novel papaya-clay combo adsorbent: up-flow adsorption of a basic dye

AbstractA novel low-cost papaya-clay combo adsorbent, hybrid clay (HYCA), was prepared from a combination of Carica papaya seeds and Kaolinite clay. HYCA breakthrough adsorption capacity was 35.46 mg/g for the adsorption of methylene blue (MB) dye in a pilot-scale fixed-bed reactor. In ca. 20 min, regeneration of MB dye-loaded HYCA reached at least 90% each cycle for five regeneration cycles. However, above 40°C, the HYCA adsorbent lost more than 50% of its adsorption capacity after five regeneration cycles. The AdDesignSTM software was used to successfully predict the breakthrough curve and scale-up performance of MB dye adsorption onto the HYCA adsorbent. The pore and surface diffusion model (PSDM) described experimental data better than the constant pattern homogeneous surface diffusion model. From economic assessment using the PSDM, the AdDesignSTM software predicted that 1 kg of HYCA can effectively treat 1.45 m3 (0.29 m3 each cycle) of water containing 1 mg/L of MB dye (with a treatment objective of...

Antioxidant and cytotoxicity effects of seed oils from edible fruits

Abstract Objective To propose a natural remedy for the some acute diseases the fatty acids profile, antioxidant and cytotoxicity potentials of seed oils from natural sources have been examined. Methods The fatty acids profile of seed oils from sweet orange, grape, lime and watermelon obtained by soxhlet extraction were trans-esterified and examined by gas chromatography-mass spectrometry (GC-MS). The antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl assay were examined and compared with gallic acid and α-tocopherol while the cytotoxicity were examined via the brine shrimp cytotoxicity assay using cyclophosphamide as a reference standard. Results Sweet orange seed contained 9,12-octadecadienoic acid (62.18%), grape seed, erucic acid (43.17), lime seed, oleic acid (52.42%) and watermelon seed linoleic acid (61.11%) as the major fatty acid present. Among the four oils tested, grape seed oil had the highest acute toxicity with LC 50 value of (156.2 ± 0.37) μg/mL while orange seed oil had the highest lethal toxicity with LC 50 (7.59 ± 0.35) μg/mL value. Lime seed oil IC 50 (14.49 ± 3.54) μg/mL showed the highest antioxidant potential of about 70% at 1 mg/mL concentration which was more significant than the reference compounds gallic acid and α-tocopherol with IC 50 value of (201.10 ± 1.65) and (54.86 ± 2.38) μg/mL respectively. The yield of oil from these seeds varied from 9.583% to 24.790% with the oils being rich in essential fatty acids. Conclusion Utilization of the seeds will reduce wastes, improve commercialization and procures hitherto neglected substances for technological and nutritional applications.

Fatty Acid Composition and Lipid Profile of Diospyros mespiliformis, Albizia lebbeck, and Caesalpinia pulcherrima Seed Oils from Nigeria.

The screening of lesser-known underutilized seeds as source of food has been a way of finding solution to food insecurity in developing nations. In this regard, oil as a class of food was extracted from the seeds of Diospyros mespiliformis  (4.72 ± 0.2%), Albizia lebbeck  (6.40 ± 0.60%), and Caesalpinia pulcherrima  (7.2 ± 0.30%). The oils were finally analyzed for their fatty acid composition, lipid classes, fatty acid distribution in the lipid fractions, and molecular speciation of the triacylglycerols, glycolipids, and phospholipids. The fatty acid composition of the oils varied with C18:2 fatty acid being the most dominant in the oils. Neutral lipids were the most abundant lipid class found in the oils while molecular species of the triacylglycerol with equivalent carbon chain number C40 was majorly present in the oils of Diospyros mespiliformis and Caesalpinia pulcherrima. The present study presents lesser-known underutilized seeds as possible sources of food.

Disinfection of water with new chitosan-modified hybrid clay composite adsorbent

Hybrid clay composites were prepared from Kaolinite clay and Carica papaya seeds via modification with chitosan, Alum, NaOH, and ZnCl2 in different ratios, using solvothermal and surface modification techniques. Several composite adsorbents were prepared, and the most efficient of them for the removal of gram negative enteric bacteria was the hybrid clay composite that was surface-modified with chitosan, Ch-nHYCA1:5 (Chitosan: nHYCA = 1:5). This composite adsorbent had a maximum adsorption removal value of 4.07 × 106 cfu/mL for V. cholerae after 120 min, 1.95 × 106 cfu/mL for E. coli after ∼180 min and 3.25 × 106 cfu/mL for S. typhi after 270 min. The Brouers-Sotolongo model was found to better predict the maximum adsorption capacity (qmax) of Ch-nHYCA1:5 composite adsorbent for the removal of E. coli with a qmax of 103.07 mg/g (7.93 × 107 cfu/mL) and V. cholerae with a qmax of 154.18 mg/g (1.19 × 108 cfu/mL) while the Sips model best described S. typhi adsorption by Ch-nHYCA1:5 composite with an estimated qmax of 83.65 mg/g (6.43 × 107 cfu/mL). These efficiencies do far exceed the alert/action levels of ca. 500 cfu/mL in drinking water for these bacteria. The simplicity of the composite preparation process and the availability of raw materials used for its preparation underscore the potential of this low-cost chitosan-modified composite adsorbent (Ch-nHYCA1:5) for water treatment.

Hura crepitans Seed Oil: An Alternative Feedstock for Biodiesel Production

Oil was extracted from the seed of Hura crepitans using hexane in a soxhlet extractor and analyzed for iodine value, saponification value and free fatty acid content. The dominant fatty acid in the oil was C18:2 (%) while the iodine value was g iodine/100 g. Biodiesel was produced from the oil using a two-step reaction system involving a first step of pretreatment via esterification reaction and a second step via transesterification reaction. The pretreatment step showed that free fatty acid in Hura crepitans seed oil can be reduced in a one-step pretreatment of esterification using H2SO4 as catalyst. The biodiesel produced from Hura crepitans seed oil had an acid value of mg KOH/g, flash point of 152 ± 1.10°C, copper strip corrosion value of 1A, calorific value of mJ/kg, cetane number of , and density of g cm−3. The process gave a biodiesel yield of % with properties within the recommended values of EN 14214.

Synthesis of Disodium Salt of Sulfosuccinate Monoester from the Seed Oil of Terminalia catappa and Its Inhibitive Effect on the Corrosion of Aluminum Sheet in 1 M HCl

Oil was extracted from the seed of Terminalia catappa and used to synthesize disodium salt of sulfosuccinate monoester using simple reaction mechanism. The disodium salt of sulfosuccinate monoester was applied as corrosion inhibitor of aluminum sheet in 1 M HCl via weight loss method. The adsorption was found to obey Langmuir isotherm. The results presented disodium salt of sulfosuccinate monoester as an efficient inhibitor of aluminum sheet corrosion in 1 M HCl.

Isolation and Characterization of Cellulose from Underexploited Golden Melon Skin

Golden melon skin (GM) is an underexploited plant resource in Nigeria from which cellulose (GMC) was isolated and characterized. Characterization was achieved using Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis, and scanning electron microscopy. GMC was further evaluated for its water holding capacity (WC), oil holding capacity (OC), water swelling capacity (SC), and heavy metal adsorption capacity. FT-IR spectroscopy revealed peaks corresponding to GMC, while the XRD diffraction planes exhibited by GMC were typical of cellulose I crystals with a crystallinity index of 40% . The thermal degradation of GMC revealed a first mass loss at 190–295 °C, second loss at 305–410 °C, and third loss 285–430 °C . The WC was 11.62 g/g, OC was 2.75 mL/g, and SC was 9.32 mL/g. The heavy metal adsorption capacity of GMC toward Cu (II) was 34.52 mg/g, and it was 28.73 mg/g toward Pb (II) in an aqueous solution. These results show that GM is a potential source of cellulose, which might have useful applications.