Evaluation of particle board production from cotton gin waste and urea-formaldehyde resin

The objective of this study was the evaluation of feasibility of producing particleboard for general use using cotton gin waste generated in Argentina and urea formaldehyde resin. The chemical composition and size distribution of particles of the ginning residue as well as mechanical and physical properties of the particleboards obtained were investigated. Density and flexural strength of particleboards produced with varying levels of urea-formaldehyde resin between 8.3 and 19.3% (solid to solid ratio) were evaluated. The effect of incorporating jute reinforcement on the mechanical properties of these boards was also analyzed. Particle boards with densities between 530 and 700 kg/m3 and variable flexural strength between 0.30 and 5.85 MPa were obtained, allowing the minimum levels required for low-density boards to be reached.

Adsorption of pharmaceuticals from aqueous solutions using biochar derived from cotton gin waste and guayule bagasse

Biochars produced from cotton gin waste (CG) and guayule bagasse (GB) were characterized and explored as potential adsorbents for the removal of pharmaceuticals (sulfapyridine-SPY, docusate-DCT and erythromycin-ETM) from aqueous solution. An increase in biochar pyrolysis temperature from 350 οC to 700 οC led to an increase in pH, specific surface area, and surface hydrophobicity. The electronegative surface of all tested biochars indicated that non-Coulombic mechanisms were involved in adsorption of the anionic or uncharged pharmaceuticals under experimental conditions. The adsorption capacities of Sulfapyridine (SPY), Docusate (DCT) and Erythromycin (ETM) on biochar were influenced by the contact time and solution pH, as well as biochar specific surface area and functional groups. Adsorption of these pharmaceutical compounds was dominated by a complex interplay of three mechanisms: hydrophobic partitioning, hydrogen bonding and π–π electron donor–acceptor (EDA) interactions. Despite weaker π–π EDA interactions, reduced hydrophobicity of SPY− and increased electrostatic repulsion between anionic SPY− and the electronegative CG biochar surface at higher pH, the adsorption of SPY unexpectedly increased from 40% to 70% with an increase in pH from 7 to 10. Under alkaline conditions, adsorption was dominated by the formation of strong negative charge-assisted H-bonding between the sulfonamide moiety of SPY and surface carboxylic groups. There seemed to be no appreciable and consistent differences in the extent of DCT and ETM adsorption as the pH changed. Results suggest the CG and GB biochars could act as effective adsorbents for the removal of pharmaceuticals from reclaimed water prior to irrigation. High surface area biochars with physico-chemical properties (e.g., presence of functional groups, high cation and anion exchange capacities) conducive to strong interactions with polar-nonpolar functionality of pharmaceuticals could be used to achieve significant contaminant removal from water. Graphic Abstract

EVALUATION OF GIN WASTE AS A GROWING SUBSTRATE, ENRICHED WITH DIFFERENT VOLUME PERCENTAGE OF THE WHEAT BRAN FOR CULTIVATION OF OYSTER MUSHROOM (PLEUROTUS OSTREATUS)

Pleurotusostreatus mushroom was cultivated on cotton gin waste amended with wheat bran in order to judge its growth potential. Two substrates (cotton gin waste and wheat bran) were employed alone and with different combinations. Experiment consisted of four treatments T0 (100 % cotton gin waste), T1(97% cotton gin waste + 3% wheat bran), T2(94% cotton gin waste + 6% wheat bran) and T3(91% cotton gin waste + 9% wheat bran). Data about time needed for commencement of spawn run, time needed for completion of mycelial growth, time needed for initiation of pinheads, time needed for harvesting of 1st, 2nd and 3rd flush, fresh weight of 1st, 2nd and 3rd flush harvested, total yield, pH of mushroom, total soluble solids of mushroom, acidity and ascorbic acid contents, reducing sugars, non-reducing sugars and total sugars of mushroom, total nitrogen, phosphorus and potassium contents of mushroom was recorded. T0 (100 % cotton gin waste) performed better as compared to other treatments.