Preparation Of Activated Carbon Based On Sludge And Its Ability To Adsorb Benzene Series

As much starker choices-and graver consequences-in battle "blue sky",the public environmental consciousness gradually strengthened,the social from all walks of life more and more emphasis on environmental pollution,ecological destruction,sludge any pile has a larger harm on environment and human,the problems existing in the traditional processing method of sludge has been exposed,environmental pollution control upgrade again.How to better and better realize the effective and resource utilization of sludge is a hot issue that needs to be solved.Petrochemical enterprises as an important source of industrial VOCs emissions,activated carbon adsorption technology has become the most widely used technology to treat the VOCs in the tank area and loading system of petrochemical enterprises,and has achieved certain treatment effects.But on the other hand,at present,the activated carbon used in the treatment of VOCs in petrochemical enterprises adopts the way of outsourcing,the price can be as high as 10,000 yuan per ton or more,which greatly increases the operation cost of enterprises,and there is still a large room for improvement in the adsorption efficiency of activated carbon.Therefore,the research and development of low-cost activated carbon adsorbents for the treatment of VOCs in petrochemical enterprises has become a hot topic in the field of carbon materials and environmental protection.Taking sludge as carbon source and using chemical activation method to prepare sludge based activated carbon is one of the important development directions of sludge resource utilization,which makes the sludge based activated carbon have more rough surface structure,more developed pore structure and stronger adsorption capacity.In this paper,the dry sludge dewatered from Qingdao Refinery is used as the carbon source,and the chemical activation method is used to prepare sludge-based activated carbon.A single activator and a compound activator are used as pore formers to investigate the adsorption performance of the sludge-based activated carbon.,The optimal preparation conditions were obtained.At the same time,the adsorption isotherm model,kinetic model,DR equation,etc.were used to analyze the adsorption performance of sludge-based activated carbon,combined with scanning electron microscopy(SEM),BET specific surface area,pore size,Fourier transform infrared spectroscopy(FT-IR)),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS)and other characterization methods,explored the difference between the adsorption capacity of commercial activated carbon and sludge-based activated carbon.The main results of the research are:(1)Use chemical activator as pore-forming agent to prepare sludge-based activated carbon(SAC),take adsorption iodine value and yield as performance inspection objects,and explore the performance of single activator and compound activator to prepare sludge-based activated carbon Happening.The results show that the optimal preparation conditions are: the carbonization temperature is 500.C.When activator concentration is 6mol/L,carbonization time is 70 min,heating rate is 10 ℃ /min,dry sludge quality: activator volume=1:1,ZnCl2:H3PO4=1:1.5,sludge-based activated carbon has greater Specific surface area and total pore volume,which makes the adsorption performance the best.(2)Explore activated carbon prepared from different carbon sources: sludge-based activated carbon,sucrose-based activated carbon,straw-based activated carbon,walnut shell-based activated carbon,and factors affecting the adsorption performance.The experimental results show that sucrose-based activated carbon has the highest carbon content and the highest carbon content due to its carbon source,sucrose,and has the best adsorption performance for benzene series under static conditions,above 700mg/g;commercial activated carbon has the lowest adsorption performance,300 mg /g,this is because commercial activated carbon contains more mesopores,and the adsorption performance is mainly determined by micropores.The saturated adsorption capacity of sludge-based activated carbon for toluene and xylene is 400.03mg/g and 366.44mg/g.(3)The SEM,TEM,infrared,XPS,XRD of the sludge-based activated carbon were characterized,and the results showed that: the sludge-based activated carbon contains more functional groups,such as:-OH,C=C,Si-O-Si,-CH(O)CH-,-CH2 and other functional groups.The presence of these polar groups,especially hydroxyl groups,increases the adsorption performance of sludge-based activated carbon,and sludge-based activated carbon contains a large amount of C,O,Zn,Mn,Pb And other elements.(4)Using static and dynamic devices to adsorb benzene series,the results show that the saturated adsorption capacity of sludge-based activated carbon for toluene is higher than the saturated adsorption capacity of xylene;and under the condition of constant temperature changes,the temperature and adsorption capacity are negative relationship.And the adsorption process of benzene series is more in line with the quasi-two-stage kinetic model;with the increase of the gas production flow rate,the adsorption amount is gradually smaller,but the range of change is not large;through the DR equation,the sludge-based active p-benzene is obtained The adsorption of the series is a physical adsorption process.