Sorption Efficiency in Dye Removal and Thermal Stability of Sorghum Stem Aerogel

Agroindustry waste containing cellulose compound, Sorghum stem, was utilized to become cellulose aerogel which was then used as dye absorbent in textile dye wastewater. Cellulose was prepared by sorghum stem powder delignification using 6%w of NaOH solution. The ratio of powder and NaOH was varied in 1:12, 1:15, and 1:20. After this process, the powder was synthesized with NaOH/Urea to produce an aerogel by the freeze-drying method. The result shows that a higher amount of NaOH in the delignification process could increase aerogel density and decrease the porosity. Thermal stability and sorption efficiency of the aerogel was analyzed in this study. Higher porosity of aerogel tends to raise % removal in methylene blue absorption. This study reveals that aerogel three times more effective than activated carbon in dye removal.

Kinetic, isotherm and thermodynamics investigation on adsorption of divalent copper using agro-waste biomaterials, Musa acuminata, Casuarina equisetifolia L. and Sorghum bicolor

Three novel and distinct agricultural waste materials, viz., Casuarinas fruit powder (CFP), sorghum stem powder (SSP) and banana stem powder (BSP) were used as low cost adsorbents for the removal of toxic copper(II) from aqueous solutions. Acid treated adsorbents were characterized by SEM, EDX and FTIR. Different factors effecting adsorption capacity were analyzed and the efficiency order was BSP>SSP>CFP. Based on the extent of compatibility to Freundlich/Langmuir/D-R/Temkin adsorption isotherm and different models (pseudo-first and second order, Boyd, Weber’s and Elovich), chemisorption primarily involved in the case of CFP and SSP, whereas, simultaneous occurrence of chemisorption and physisorption was proposed in the case of BSP. Based on the observations, it was proposed that three kinetic stages involve in adsorption process viz., diffusion of sorbate to sorbent, intra particle diffusion and then establishment of equilibrium. These adsorbents have promising role towards removal of Cu(II) from industrial wastewater to contribute environmental protection.

Chemical oxygen demand reduction from coffee processing waste water – A comparative study on usage of biosorbents prepared from agricultural wastes

<div> <p>The utilization of three novel and distinct agricultural waste materials, namely casuarina fruit powder (CFP), sorghum stem powder (SSP) and banana stem powder (BSP) as low cost adsorbents for reducing chemical oxygen demand (COD) levels of coffee industry wastewater has been examined. Prepared adsorbents were characterized by scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopic (EDAX) and <a href="http://en.wikipedia.org/wiki/Fourier_transform_infrared_spectroscopy" target="_blank">Fourier Transform Infrared Spectroscopy</a>. The effects of parameters like adsorbent dose, pH, temperature, agitation rate and time of adsorption on the reduction of COD levels were analyzed for each adsorbent individually and the efficiency order is CFP&gt;SSP&gt;BSP. Based on the extent of compatibility to Freundlich/Langmuir adsorption isotherm and different models (pseudo-first order and second order, Boyd, Weber&rsquo;s and Elovich), simultaneous occurrence of chemisorption and physisorption was proposed. Based on the observations, it is proposed that three kinetic stages involve in adsorption process viz., diffusion of sorbate to sorbent, intra particle diffusion and then establishment of equilibrium. As these three adsorbents exhibit adsorption capacity more than 80%, the adsorbents prepared from agricultural wastes have promising role towards reduction of COD from industrial wastewater to contribute environmental protection. &nbsp;</p> </div> <p>&nbsp;</p>