Sorption of distillery spent wash onto fly ash: kinetics, mechanism, process design and factorial design.
Batch and continuous experiments were performed for the sorption of distillery spent wash onto fly ash particles. The Freundlich and pseudo-second order equation were found to fit the equilibrium data perfectly. The Weber-Morris intraparticle diffusion isotherm equation was used to predict the sorption mechanism and the predicted equation for 10% dilution of spent wash sorption is q(t)=1.1344t(0.5)+33.304. The optimization using 2(3) factorial design of experiments provides optimal removal of color of 93% for dilution (5%), dosage of adsorbent (10g) and temperature (293K). The actual color removal at optimal conditions was 92.24%, confirms close to the factorial design results. The complete error analysis using six non-linear error functions: Chi-square (chi(2)); sum of square errors (SSE); composite fractional error function (HYBRD); derivative of Marquardt's percent standard deviation (MPSD); average relative error (ARE); sum of absolute errors (EABS) were calculated. Free energy of adsorption at 293K (DeltaG(0)=-1574.67J), enthalpy change (DeltaH(0)=-32.5487KJ) and entropy change (DeltaS(0)=105J/K) were calculated to predict the nature of adsorption. Adsorption studies in a packed column were evaluated using Bed depth service time model, Thomas model and Adams-Bohart model.
Krishna Prasad
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School of Chemical & Biotechnology, SASTRA University, Thanjavur 613402, India. rkprasad_cbe@rediffmail.com
Srivastava
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D000327:Adsorption; D019149:Bioreactors; D002244:Carbon; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002627:Chemistry, Physical / Q000379:methods; D060729:Coal Ash; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D015233:Models, Statistical; D010316:Particle Size; D052638:Particulate Matter; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors; D018508:Water Purification / Q000379:methods
D060729:Coal Ash; D007220:Industrial Waste; D052638:Particulate Matter; D002244:Carbon