Molecular Interactions Associated with Coagulation of Organic Pollutants by 2S Albumin of Plant Proteins: A Computational Approach.

The removal of organic pollutants is a major challenge in wastewater treatment technologies. Coagulation by plant proteins is a promising technique for this purpose. The use of these proteins has been experimentally investigated and reported in the literature. However, the determination of the molecular interactions of these species is experimentally challenging and the computational approach offers a suitable alternative in gathering useful information for this system. The present study used a molecular dynamic simulation approach to predict the potentials of using Moringa oleifera (MO), Arachis hypogaea, Bertholletia excelsa, Brassica napus, and Helianthus annuus plant proteins for the coagulation of organic pollutants and the possible mechanisms of coagulation of these proteins. The results showed that the physicochemical and structural properties of the proteins are linked to their performance. Maximum coagulation of organic molecules to the proteins is between 50-100%. Among five proteins studied for coagulation, Brassica napus and Helianthus annuus performed better than the well-known MO protein. The amino acid residues interacting with the organic molecules play a significant role in the coagulation and this is peculiar with each plant protein. Hydrogen bond and π-interactions dominate throughout the protein-pollutants molecular interactions. The reusability of the proteins after coagulation derived from their structural quality analysis along with the complexes looks promising and most of them are better than that of the MO. The results showed that the seed proteins studied have good prediction potentials to be used for the coagulation of organic pollutants from the environment, as well as the insights into their molecular activities for bioremediation.

Effect of Pith/Fiber Separation, Binders and Hybridization on Energy Density and Physical Properties of Bagasse Briquettes.

Improvements on energy density of loose biomass such as sugarcane feedstock is crucial in the technology of biomass energy conversion and generation. South Africa is one of the producers and refiners of sugarcane. High energy density of sugarcane bagasse biomass through separation and briquetting is imperative in developing adequate streams and quality energy generation from sugarcane upstream milling processes. Unseparated bagasse and separated fractions of fiber and pith possess energy contents of about: 16.14 MJ/kg, 17.73 MJ/kg and 15.74 MJ/kg respectively. Fiber fractions have high energy content than bagasse and pith which demonstrates that pith fraction from bagasse lowers energy density. However, the use of starch and PVA (Polyvinyl Alcohol) as binders during briquetting contributed no significant difference in the overall energy density of the biomass briquettes produced. In the same vein, the addition of 50% charcoal as the hybrid component significantly improves the energy density and the physical properties of briquettes, biomass fractions of bagasse, fiber and pith to: 19.43 MJ/kg, 19.57 MJ/kg and 18.37 MJ/kg respectively. Fiber fraction remains the biomass fraction with highest energy content as compared to other fractions. After briquetting and drying of briquettes to moisture content below 12%, there was a significant improvement on the burning rate, briquetting, binder, hybridization which does improve the biomass briquettes characteristics. Separation of bagasse is crucial under certain conditions since there are no significance differences in the energy density of bagasse fractions. However, the use of PVA and charcoal does pose the necessity of bagasse separation from its fractions for briquetting.