Microwave-assisted solvent extraction of castor oil from castor seeds

This study was aimed at evaluating the physicochemical properties and oxidation stability of castor oil using microwave-assisted solvent extraction(MAE). MAE was performed using 5% ethanol in hexane as solvent at different extraction times, power intensities and solvent-to-feed(S/F, ml of solvent to gram of feed) ratios.The process parameters were optimized by statistical approach using historical data design of response surface method(RSM). The oils were characterized for yield, physicochemical properties, dielectric properties and oxidation stability, and comparison was also made with oil extracted using Soxhlet method. Results show that the maximum oil yield of 37% was obtained at 20 min with microwave power intensity of 330 W and S/F ratio of 20. The main fatty acid composition of castor oil is ricinoleic acid. The density, refractive index, dielectric properties and oxidation stability of oils are not affected by the extraction methods and extraction parameters of MAE. However, the MAE-extracted oil is more viscous compared to that by Soxhlet method. With extra caution on oil oxidation, MAE could be a promising solvent extraction method with an 86% less in processing time and a higher yield.

Relationship between Helium Degassing of Cattle-Manure-Compost Adsorbents and Copper Ions Removal

This work was aimed to investigate the effect of helium degassing of cattle-manure-compost (CMC) based activated carbons on the adsorptive removal of copper ions from aqueous solution. Degassing temperatures were 500℃, 800℃ and 1000℃. Activated carbons were characterized according to surface chemistry and pore structures. Adsorption of copper ions was carried out using the conventional bottle-point technique to which the equilibrium data were correlated to Langmuir and Freundlich models. Results indicated that the uptake of copper ions could be well characterized by Langmuir model. It was found that the adsorption of copper ions decreased with significant decrease in surface area as a result of helium degassing at higher temperature. The increase of electron density on graphene layers offered higher affinity towards copper ions at lower equilibrium concentration. It was inferred that copper ions favorably adsorbed on mesopores at lower equilibrium concentration and switched to micropores at higher equilibrium concentration.

Beta-cyclodextrin adsorbents to remove water pollutants-a commentary

Beta-cyclodextrin-based adsorbent is a promising adsorbent because it has unique characteristics and able to form host-guest complexes with various organic compounds.Adsorption using beta-cyclodextrin-based adsorbent has continuously improved by various preparation strategies and crosslinking agents.This commentary aims to highlight the preparation strategies,properties,and adsorption mechanisms of beta-cyclodextrin-based adsorbents.The adsorbents can be generally classified according to the preparation methods and display high adsorption capacity especially for dyes.Particularly,composite/nanocomposite beta-cyclodextrin-based adsorbents exhibit outstanding adsorption capacity even though the surface area is lower than that of porous and magnetic betacyclodextrin-based adsorbents.The beta-cyclodextrin/chitosan functionalized graphene oxide hydrogel with specific surface of 17.6 m^(2)·g^(–1)yields an extraordinarily maximum adsorption capacity of 1499 mg·g^(–1)methylene blue,while beta-cyclodextrin/chitosan modified with iron(Ⅱ,Ⅲ)oxide nanoparticles displays a much greater maximum adsorption capacity at 2780 mg·g^(–1).The hydrophobic interaction,functional groups,hydrogen bonding,and electrostatic interaction govern the adsorption to a greater capacity.Although this commentary is not exhaustive,the preparation strategies and illustrated mechanisms provide useful insights into the adsorbent–adsorbate interactions,costeffective analysis,challenges,and future directions of betacyclodextrin-based adsorbents in wastewater treatment.