Study On Preparation And Adsorption Of Activated Carbon From Sludge And Orange Peel

Due to the acceleration of the process of industrialization and urbanization in China in the past 30 years,the continuous development of social economy and the improvement of people’s living standards,the production of sewage sludge has grown in an uncontrollable and large scale under this wave.With the increasingly stringent regulations for the treatment and disposal of sludge,new reliable and long-lasting explorations must be conducted in the traditional sludge treatment field.Sewage sludge itself is a kind of waste generated from a certain carbonaceous wastewater treatment plant,and orange peel is a high-carbon agricultural waste containing a lot of cellulose.The two have a certain quality ratio to prepare activated carbon.It is a good way to turn waste into treasure.This project mixes sewage sludge and orange peel using a classical chemical activation method to make activated carbon.The optimum process condition obtained by orthogonal experiments is the dipping ratio of 4:1,the activation time of 36 h,the carbonization temperature of 500 °C,and the material ratio of 1:1.The analysis found that the order of magnitude of the influence of the four factors was :material ratio>dipping ratio> activation time> carbonization temperature.The activated carbon obtained under the optimum process conditions was measured and found to have a BET specific surface area of 244.99 m2/g,a total pore volume of 0.1875 cm3/g,and an average pore size of 7.3569 nm.The iodine number of activated carbon based on orange peel and sludge was 462 mg/g.The FT-IR spectrometer detection and BET detection of the activated carbon material prepared under the optimum process conditions find that the type of adsorption and desorption of nitrogen on the activated carbon belonged to the second type of adsorption isotherm,indicating that the adsorption of nitrogen on the activated carbon was consistent with the multilayer adsorption theory.The prepared activated carbon was used to adsorb methylene blue solution.The effects of adsorption time,activated carbon addition and initial concentration of methylene blue on the adsorption capacity and removal efficiency were investigated.As a result,it was found that as the time went by,both the amount of adsorption and the removal efficiency showed an increasing trend and eventually reached saturation.With the increase of activated carbon addition,the removal efficiency showed an increasing trend,while the adsorption amount decreased.With the increase of initial concentration of methylene blue solution,the adsorption capacity of activated carbon showed an increasing trend,while the removal efficiency decreased.Through adsorption kinetic experiments and results analysis,the secondary Lagergren model has the highest degree of fitting.The use of sludge and waste orange peel as raw material for preparing biomass activated carbon can solve the pollution problem of sludge and orange peel on the one hand,and can also obtain activated carbon on the other hand,which provides an economical treatment and disposal of sewage sludge.