A low-cost adsorbent (wheat plant ash) prepared from agricultural waste for removal of paraquat from aqueous solutions

26-34A low-cost adsorbent (wheat plant ash) has been prepared using a common agricultural waste (wheat straw) and its physicochemical characteristics, including chemical, physical, mineralogical, and morphological, and adsorption efficacy are investigated. WPA is characterized by SEM (scanning electron microscopy), CHNS(ultimate analysis) analysis, Brunauer–Emmett–Tellersurface area technique, and Fourier transform infrared method. The BET surface area of wheat plant ash was found to be 37 m2/g. To evaluate its adsorption capacity, paraquat is chosen as the adsorbate. Batch adsorption is performed by varying adsorbent dosage, initial concentration, and contact time. Experimental data are fitted to both kinetic and isotherm models. Pseudo-first-order and pseudo-second-order kinetic models are applied to experimental data, which indicated that the latter model had the best fit. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models are then applied to the equilibrium data. The adsorption capacity of WPA for paraquat removal, determined using the Langmuir isotherm, is found to be approximately 241.3 mg/m2 at 303 K

Groundnut plant ash: Characterisation and adsorption efficacy study for removal of paraquat dichloride

35-42For the first time combustion residue of agricultural waste i.e. groundnut plant is characterized in detail and explored as an adsorbent for removal of chlorinated herbicide, paraquat. The study investigates the chemical, physical, mineralogical, and morphological characteristics of GPA (Groundnut Plant Ash) adsorbent produced using groundnut plant. GPA has been characterized using the Fourier Transform Infrared (FTIR) spectroscopy to determine the functional groups, and Scanning Electron Microscopy (SEM) to examine the surface morphology of the carbon. Batch adsorption is performed by varying adsorbent dosage, initial concentration and contact time. Result shows that the kinetic models mainly the pseudo-second order and Elovich model had the best fit. The equilibrium data are analyzed using different isotherm models. The adsorption capacity of GPA for paraquat removal is found 265.71 mg/m2  which is the highest reported value

Process intensification strategies for enhanced holocellulose solubilization

Biorefinery sector has become a serious dispute for cleaner and sustainable development in recent years. In the present study, pretreatment of pineapple peel waste was carried out in high pressure reactor using various pretreatment-enhancers. The type and concentration effect of each enhancer on hemicellulose solubilization was systematically investigated. The binary acid (phenol + sulfuric acid) at 180 °C was found to be superior amongst other studied enhancers, giving 81.17% (w/v) hemicellulose solubilization in liquid-fraction under optimized conditions. Solid residue thus obtained was subjected to enzymatic hydrolysis that resulted into 24.50% (w/v) cellulose breakdown. Treated solid residue was further characterized by scanning electron microscopy and fourier transform infrared spectroscopy to elucidate structural changes. The pooled fractions (acid treated and enzymatically hydrolyzed) were fermented using Clostridium acetobutylicum NRRL B 527 which resulted in butanol production of 5.18 g/L with yield of 0.13 g butanol/g sugar consumed. Therefore, pretreatment of pineapple peel waste evaluated in this study can be considered as milestone in utilization of low cost feedstock, for bioenergy production.Peer reviewe