Preparation and characterization of activated Teff (Eragrostis) straw Biochar for Methylene Blue Adsorption

Abstract

An Activated Biochar Adsorbent Obtained From Teff (Eragrostis) Straw Was Prepared Using Two Step" Carbonization And Activation Technique And Its Performance Was Evaluated For The Adsorption Of Mb. The Activated Biochar Also Characterized By Scanning Electron Microscopy (Sem), Ft-Ir And Bet. The Effects Of Ratio (Koh/Biochar: W/W), Temperature, And Time Of Carbonization On The Removal Of Methylene Blue By Atsb Biochar Were Evaluated To Determine The Optimum Treatment Conditions To Come Up With Best Performance. The Adsorption Performance For The Removal Of Methylene Blue (Mb) Was Deeply Investigated. The Effects Of Ph, Initial Dye Concentration, Contact Time, Adsorbent Dosage, And Temperature On The Adsorption Of Mb Onto Atsb Were Also Investigated. Sem Results Shows That The Atsb Were Porous And Also The Bet Result Shows Surface Area Of Atsb Became 259.21 M2/G Which Is Much Higher Than Raw Bc Surface Area Which Was 4.628 M2/G. The Best Operating Conditions To Make Activated BiocharWere Koh/Teff (Eragrostis) Straw Ratio 2:1, Activation Temperature 450??C, And 2 Hours Of Holding Time In The Activation Chamber. The Study Conducted On The Adsorption Kinetics Indicated That Pseudo-First-Order Kinetics (R2=0.967) Guided The Adsorption Process. The Langmuir Model(R2=0.99) Was Shown To Be The Best Fit For The Experimental Adsorption Isotherm, Meaning That Mb Adsorption By Porous Biochar Occurred As A Monolayer Adsorption With A Maximal Monolayer Adsorption Capacity Of 59.17 Mg/G. Gibbs Free Energy, Enthalpy, And Entropy Were Determined As Thermodynamic Parameters. The Positive Value Of ??H0 (13.65) Showed That The Nature Of Adsorption Process Was Endothermic. The Positive Value Of ??S0(0.99) Indicated An Increase In The Randomness At The Solid/Solution Interface During The Adsorption Of The Mb Dye On Teff Straw Biochar. ??G0(-15.69) Has Negative Value And Which Indicate That The Process Is Spontaneous The Atsb Has A Presentable Recyclability, According To The Regeneration Analysis.The Atsb Developed In This Study Has The Potential To Treat Dye Wastewater In Real Applications Due To Its Strong Adsorption Ability.