Showing papers by "B.H. Hameed published in 2019"

Biofilm of cross-linked Chitosan-Ethylene Glycol Diglycidyl Ether for removal of Reactive Red 120 and Methyl Orange: Adsorption and mechanism studies

Abstract: In this study, a biofilm of cross-linked Chitosan- Ethylene Glycol Diglycidyl Ether (Chi-EGDE) was prepared and coated onto glass plate to act as a biosorbent for two structurally different Reactive Red 120 (RR120) and Methyl Orange (MO) dyes by applying non-conventional adsorption system without separation and filtration processes. The characterizations reveal that the Chi-EGDE biofilm has a low swelling index, good mechanical strength on glass plate, relatively high content (64.4%) of free amine (-NH2) groups, and pHpzc of ∼6.8 indicating a positive surface charge occurs below pHpzc. The adsorption data of RR120 and MO by the cross-linked Chi-EGDE biofilm were in agreement with Langmuir isotherm at 303 K, with maximum adsorption capacities of 165.3 mg/g and 131.2 mg/g, respectively. The kinetic data were well described by pseudo-second-order kinetic model. The adsorption process was spontaneous and endothermic in nature at cross-linked Chi-EGDE biofilm thickness of 4.24 μm. The mechanism of adsorption included mainly hydrogen bonding interaction, electrostatic attractions, and n-π stacking interaction. This study reveals that the cross-linked Chi-EGDE biofilm as a good candidate for adsorption of two structurally different reactive and acid dyes as it does not require any filtration process and adsorbents recovery during and post-adsorption process.

Hydrogenation of glucose and fructose into hexitols over heterogeneous catalysts: A review

Abstract: Biomass-derived sugars are a promising source of high-value chemicals because of their low cost, availability, and renewability. Catalytic hydrogenation of fructose and glucose into hexitols, including sorbitol and mannitol is of great industrial importance due to hexitols application in the food, medical, chemical, and petroleum industries. For this purpose, heterogeneous catalysts are preferred owing to their high efficiency, easy separation, and reusability. In this review article, the hydrogenation performance of both sugars into hexitols was discussed and analyzed under various reaction conditions. The catalyst stability and hydrogenation kinetics are also reviewed. Moreover, important challenges and promising routes are suggested for the future development of the heterogeneous catalytic hydrogenation of sugars to hexitols.

Kinetics of Pyrolysis of Durian (Durio zibethinus L.) Shell Using Thermogravimetric Analysis

Abstract: The characteristics and kinetics of durian shell (DS) pyrolysis were investigated using non-isothermal thermogravimetric analysis (TGA). DS is a celluloserich biomass with high volatile matters content, which is suitable for bio-oil production. Thermal decomposition experiments were performed under nitrogen flow at various heating rates (i.e., 5°C min–1, 10°C min–1 and 20°C min–1). The model-fitting method represented by Coats-Redfern was applied on the experimental TGA data of DS pyrolysis. The decomposition of DS was divided into three stages: first stage (59°C–200°C) involved removal of moisture and light volatiles; second stage (200°C–400°C) showed decomposition of cellulose and hemicellulose; and third stage (above 400°C) presented lignin decomposition. There was 56% weight loss observed in second stage, revealing that decomposition of cellulose and hemicellulose contributed the most on volatile production. The model shows that the activation energy was between 42.08 kJ mol–1 and 84.40 kJ mol–1 for the second stage of the pyrolytic process from 200°C to 400°C using different decomposition mechanisms. The Coats-Redfern method is applied successfully for the correlation of experimental TGA data with an average correlation coefficient (R2) of 0.991 while one-way diffusion model D1 gave the highest correlation coefficient of 0.998. DS biomass is a suitable raw material for energy or chemicals production.

Effects of nanocasting parameters on surface area properties of PEG 400-based ordered mesoporous carbon

Abstract: In this work, ordered mesoporous carbon (OMC) was synthesised via the nanocasting process using hexagonal mesoporous silica (HMS) as the template and polyethylene glycol 400 (PEG 400) as the carbon precursor by varying four vital process conditions, namely, carbonisation temperature, dwelling time, heating rate, and carbon loading. The best conditions were selected based on the ability of the OMC samples to remove methylene blue (MB). ABA-16 exhibited the highest total surface area (1,020 m2.g−1) with its pore diameter measured at 3.89 nm, and a total pore volume of 0.9976 cm3.g−1. It was prepared using 2.5 g of PEG 400 per gram of HMS, carbonised at 800 °C, with a heating rate of 1°C.min−1, and 240 min of dwelling time. A series of batch adsorption tests was conducted on MB at different initial concentrations at 30– 50 °C. The maximum MB adsorption capacity, Qm was at 394.88 mg.g-1 at 303 K. For all tested conditions, Freundlich produced better fittings than Langmuir isotherm model. All these findings suggested that nanocasting parameters play important roles in producing functional OMC with good physicochemical properties for the removal of pollutants from water bodies.