Removal Of Fluoride From Drinking Water Using Thermally Activated Mixture Of Bone And Coffee Husk

Abstract

Due To The Negative Health Impacts Of High Level Of Fluoride In Drinking Water, The Search For An Appropriate And Locally Available Technology For Its Removal From Contaminated Water Still Remains Very Critical. Therefore, This Research Investigates The Potential Of Thermally Activated Mixtures Of Cattle Bones And Coffee Husk As Technically Simple, Cost Effective And Easily Transferable Technology For Defluoridation Of Drinking Water. To Conduct The Experiment, The Bones And Coffee Husk Mixtures With 1:1 (100g Each) And 2:1 (150-To-75 G) Bone-To-Coffee Husk Ratio Were Pyroly Sised At Six Different Temperatures (300 Oc, 400 ??C, 500 Oc, 600 ??C, 700 Oc And 800 Oc) For 2h And 200g Of Each Adsorbents Were Also Separately Charred At Pyrolysis Temperature Of 500oc For The Same Pyrolysis Time In A Muffle Furnace. The Pyrolysis Product Obtained Were Then Ground In A Grinding Machine, And Sieved Through A Mesh Size Of 250??M. The Prepared Adsorbent Were Characterized By Its Percentage Removal Of Fluoride Ions From Artificial Fluoridated Water And Naturally Fluoridated Water Under The Optimized Contact Time, Adsorbent Dosage, Ph And Initial Concentration Of Fluoride. The Proximate Analysis, Point Of Zero Charge And Specific Surface Area Of The Prepared Adsorbent Were Also Determined. The Adsorption Efficiency Of Adsorbent Which Pyrolyzed In A Mixture Of 2:1 Bone-Coffee Husk At A Pyrolysis Temperature Of 500oc Was Better Than That Of 1:1 Ratio And All Ratios Of Separately Charred Bone And Coffee Husk. This Indicates That The Chemical Composition Of Bone May Activate Carbons From Coffee Husk When They Are Pyrolyzed Together. The Less Fluoride Uptake Below 400oc Was Due To Incomplete Conversion Of Organic Carbons To Inorganic Whereas, Beyond 600oc Was Due To The Distortion (Damage) Of Hydroxyapatite Structure Of The Bone. The Adsorption Efficiency Of Bonecoffee Husk Char For Fluoride Removal Was Increased With Adsorbent Dosage And Contact Time Before Equilibrium And It Was Appreciable Around Neutral Ph. The Linear Regression Analysis Of Kinetic Data Confirmed That Pseudo-Second Order Rate Expression Best Fitted While Freundlich Isotherm Model Equation Was Found To Fit The Equilibrium Data For Fluoride Adsorption.