Study On The Preparation Of Fishbone Charcoal And Application As The Adsorbent For Pb(?) And Methylene Blue

In order to realize the fisheries waste comprehensive utilization,this thesis used the fishbone as the raw material to prepare the adsorbent and carry out the adsorption study of lead ions and methylene blue.First of all,the preparation process was discussed to determine the optimum preparation conditions of fishbone charcoal.Second,the adsorption behaviors and mechanisms of lead ions onto the fishbone charcoal were explored.NaOH modification for fishbone charcoal was also examined.The adsorption behaviors and mechanisms of methylene blue onto fishbone charcoal and NaOH?modified fishbone charcoal were compared.The pyrolysis method was used to prepare the fishbone charcoal,and a better preparation condition was determined:nitrogen condition,pyrolysis temperature of500?,pyrolysis rate of 5?/min and maintaining a constant temperature at 500?for1 h.The average grading size and specific surface area of the fishbone charcoal was178.10?m and 156.87m~2/g,respectively.The results showed that,the adsorption process of lead ions onto fishbone charcoal was matched to Langmuir isotherm model and first?order kinetics model.It was an unspontaneous endothermic process.The maximum adsorption capacity of lead ions was 961.13mg/g.The adsorption process of methylene blue onto fishbone charcoal was fitted with Freundlich isotherm model and second?order kinetics model,and it was an unspontaneous endothermic process.The maximum adsorption capacity of methylene blue was 69.00mg/g.Studies showed that the adsorption mechanisms of lead ions onto fishbone charcoal was given priority to ion exchange as well as physical adsorption;and the adsorption mechanism of MB onto fishbone charcoal was mainly physical adsorption.In order to further improve the fishbone charcoal adsorption capacity of methylene blue,fishbone charcoal alkali modification conditions were determined.The results showed that,the maximum adsorption capacity of methylene blue adsorption onto NaOH modified fishbone charcoal reached to 605.81mg/g,which was 10 times that of the fishbone charcoal.And results also showed that,the adsorption process of methylene blue onto the NaOH modified fishbone charcoal was matched to Freundlich isotherm model and first?order kinetics model,and was a spontaneous endothermic process.The adsorption mechanism of methylene blue onto NaOH modified fishbone charcoal concludes chemical adsorption and physical absorption.