Recent advances on graphyne and its family members as membrane materials for water purification and desalination.

Graphyne and its family members (GFMs) are allotropes of carbon (a class of 2D materials) having unique properties in form of structures, pores and atom hybridizations. Owing to their unique properties, GFMs have been widely utilized in various practical and theoretical applications. In the past decade, GFMs have received considerable attention in the area of water purification and desalination, especially in theoretical and computational aspects. More recently, GFMs have shown greater prospects in achieving optimal separation performance than the experimentally derived commercial polyamide membranes. In this review, recent theoretical and computational advances made in the GFMs research as it relates to water purification and desalination are summarized. Brief details on the properties of GFMs and the commonly used computational methods were described. More specifically, we systematically reviewed the various computational approaches employed with emphasis on the predicted permeability and selectivity of the GFM membranes. Finally, the current challenges limiting their large-scale practical applications coupled with the possible research directions for overcoming the challenges are proposed.

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 for the 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 min) and pH (3-10) influenced the removal efficiency and quantity adsorbed. A maximum of 99.3% removal efficiency was obtained at optimum conditions. AFMC physicochemical properties (surface area 1329 m2/g and particle size 300 µm < Ф < 250 µm) enhanced its efficiency. Based on R2 > 0.97 and consistently low values of adsorption statistical error functions (ASEF), equilibrium data were best fitted to Freundlich isotherm. Kinetic data were best described by a pseudo-second-order model with consistent R2 > 0.98 and validated by ASEF. The mechanism of the process was better described by intraparticle diffusion. Evidence of the adsorption process was confirmed by the change in morphology via Scanning Electron Microscopy (SEM) and surface chemistry by Fourier Transform infrared (FTIR). 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.

Hot air convective drying of hog plum fruit (Spondias mombin): effects of physical and edible-oil-aided chemical pretreatments on drying and quality characteristics.

This aim of this study was to evaluate the effects of pretreatments and temperature on the hot air drying characteristics of hog plum fruits. Hog plum fruits were pretreated with olive oil/K2CO3 or sunflower oil/K2CO3 at 28 °C and olive oil/NaOH cum blanching at 96 °C for 15s, hot water at 96 °C for 15s, and dried in a hot air drier at 50, 60, and 70 °C. Mathematical models were used to fit the data of drying and rehydration kinetics. Results showed that increase in temperature reduced drying time, increased effective diffusivity and shrinkage. Sunflower oil aided chemical pretreated sample had the shortest drying time (780 min) and highest effective diffusivity (6.3 × 10-8 m2/s) at 60 °C, faster rehydration ability at 60 °C, highest retention rate for ascorbic acid (15 %), phenolic content (29 %), and antioxidant activity (12.3 %), while olive oil aided chemical (K2CO3) pretreated sample had the shortest drying time at 50 °C (990 min) and 70 °C (600 min), lowest shrinkage (48.5 %), slower rehydration capacity at 40 °C, and lowest colour change (ΔE = 11.5). Modified Henderson and Pabis and Vega-Gálvez were superior to other fitting models in predicting the drying and rehydration kinetics. Sunflower oil/K2CO3 pretreatment could help improve the drying and quality characteristics of hog plum.

Interactive effects and modeling of some processing parameters on milling, cooking, and sensory properties for Nigerian rice using a one-step rice milling machine.

This study investigates the interactive effects of processing parameters on the quality of milled rice using a one-step milling machine. Also, predictive models were generated using response surface methodology. The processing parameters were moisture content (10-14 % dry basis), shaft speed of rotation (600-900 rpm), and polishing time (1-3 min). The quality parameters evaluated were milling (head rice yield, percentage broken rice, fine broken rice, and milled rice yield), cooking (optimum cooking time, kernel elongation ratio, and width expansion ratio), and sensory (flavor, aroma, appearance, texture, and overall acceptability) properties. The results showed that the interactive effects of moisture content, shaft speed, and polishing time were significant (P < 0.05) on percentage broken rice, milled rice yield, fine broken rice, optimum cooking time, kernel elongation ratio, width expansion ratio, aroma, and appearance but was not significant on head rice yield, flavor, texture, and overall acceptability. These results were similar to the regression models generated. In conclusion, the interactive effects of these processing parameters affect all the cooking properties but not all milling and sensory properties while using a one-step milling machine.

Drying characteristics of yam slices (Dioscorea rotundata) in a convective hot air dryer: application of ANFIS in the prediction of drying kinetics.

This study applied Adaptive Neuro-Fuzzy Inference System (ANFIS) to predict the moisture ratio (MR) during the drying process of yam slices (Dioscorea rotundata) in a hot air convective dryer. Also the effective diffusivity, activation energy, and rehydration ratio were calculated. The experiments were carried out at three (3) drying air temperatures (50, 60, and 70 °C), air velocities (0.5, 1, and 1.5 m/s), and slice thickness (3, 6, and 9 mm), and the obtained experimental data were used to check the usefulness of ANFIS in the yam drying process. The result showed efficient applicability of ANFIS in predicting the MR at any time of the drying process with a correlation value (R2) of 0.98226 and root mean square error value (RMSE) of 0.01702 for the testing stage. The effective diffusivity increased with an increase in air velocity, air temperature, and thickness and the values (6.382E -09 to 1.641E -07 m2/s). The activation energy increased with an increase in air velocity, but fluctuate within the air temperatures and thickness used (10.59-54.93 KJ/mol). Rehydration ratio was highest at air velocity×air temperature×thickness (1.5 m/s×70 °C × 3 mm), and lowest at air velocity × air temperature×thickness (0.5 m/s×70 °C × 3 mm). The result showed that the drying kinetics of Dioscorea rotundata existed in the falling rate period. The drying time decreased with increased temperature, air velocity, and decreased slice thickness. These established results are applicable in process and equipment design, analysis and prediction of hot air convective drying of yam (Dioscorea rotundata) slices.