Sludge-based Activated Carbon Preparation With The Aid Of Fenton And The Potential Application In Wastewater And Odor Control

Activated carbon (AC) from sludge is one of the promising ways to dispose andutilized the sewage sludge, while the resulted AC is poor quality using the traditionalactivation methods due to the cell wall barrier of sewage sludge. A novel activationmethod of Fenton was introduced to improve the sludge based AC here, and thepretreatment and pyrolysis conditions were optimized subsequently. The obtained ACis characterzed in terms of XRF、FTIR、XRD and so on, and were also applied in thedegradation of dye wastewater and the removal of H2S.The main conclusions are asfollows:(1)The optimal conditions for preparing sludge activated carbon by Fentonreagent under the experimental:H2O2dosage of5%,H2O2and FeSO47H2O dosingratio of5:1,initial pH of3,the activation time of2h,sludge containing solid rate of1.0%,carbonization temperature of600℃,carbonization time of2.0h,carbonizationheating rate of10℃/min.Iodine value of sludge-based activated carbon was347mg/g,BET specific surface area was253m2/g.The total pore volume was0.184cm3/g,the microporosity was42%.(2)The adsorption capacity of sludge-based activated carbonprepared by Fentonreagenton methyl orange and methylene blue were67.3mg/g and46.1mg/g. Sludge-based activated carbon adsorption properties of anionic dye better than cationicdye.Two dyes adsorbed on activated carbon are endothermic process,the adsorptionprocess is physical adsorption processes typical.Sludge-based activated carbon fordye adsorption process conforms to pseudo-second model,themajor rate-limiting stepof dye adsorption on activated sludge-base is the proliferation of external surface andinterfacial diffusion layer in the middle.(3)Sludge-based activated carbon was used as the catalyst for the degradation of methylenen blue.Catalyst dosage of1.5g/L,H2O2dosage of25mM,initial pH of5,reaction temperature of45℃, the highest removal efficiency of methylene blue andTOC, respectively,was98.6%and68.3%.H2O2played a main role in the degradationprocess.(4)Sludge-based activated carbon for H2S removal efficiency increases as theamount of activated carbon increases. When aged refuse and activated carbonmineralization ratio was7:3,the total H2S removal efficiency was78.8%.0.08mL/g35℃is the optimum condition of H2S removal.(5) The rate of microporous in activated carbonis47%,whichcan adsorb H2Sefficiently.The Fe and Ca elements in the sludge-based activated carbon can form acrystal structure based on Ca2Fe2O5,which can participate in the oxidation-reductionreactionof H2S.