Study On The Optimized Preparation Of Carp Charcoal And Its Adsorption To Diesel Oil

Crude oil,refined oil,and other organic wastes such as petroleum,COD,sulfide,etc.,are easily generated during storage.If the petroleum pollutants in the discharged wastewater exceed the standard,it will have a serious impact on the entire ecological environment and human health.The advanced treatment of oily wastewater is often carried out using activated carbon adsorption.However,the activated carbon is expensive and difficult to reproduce.At present,studies on bone carbon in China and abroad mainly focus on the adsorption of heavy metals,and studies on the adsorption of organic pollutants such as petroleum have not been found.In this thesis,firstly,the bone of squid was used as raw material.K₂CO₃ was used as the activator after the initial carbonization.The preparation conditions of fish bone charcoal were optimized through orthogonal test and single factor verification experiment,and BET,SEM,XRD and FTIR were applied to the fishbone charcoal.Characterization.Secondly,activated carbon adsorption of activated carbon was used to test the static adsorption of diesel oil and the number of repeated use of fish bone charcoal was studied.Finally,the mechanism and mechanism of carbon adsorption process of fish bone were studied by adsorption thermodynamics and adsorption kinetic model.The main conclusions are as follows:?1?The optimum conditions for the modification of fish bone charcoal by K₂CO₃activation method are as follows:the ratio of alkali to carbon is 3:1,the immersion time is 24 hours,the activation temperature is 750°C,and the activation time is 90 minutes.After activation,the BET of fish bone charcoal was as high as 205.98 m²/g,and the yield of fish bone char was 38.59%.?2?The surface of raw fish bones after being pyrolyzed carbonized and activated becomes rough,forming more pore structures and surface microcrystals;After activation,the calcium hydroxy phosphate crystals of the fishbone charcoal become larger,the crystallinity becomes higher,and new crystallites of calcium hydroxide and potassium bicarbonate are newly generated.In addition,the BET specific surface area of??fish bone activated by K₂CO₃ increased from 69.77 m²/g to 205.98 m²/g,the total pore volume increased from 0.192 cm³/g to 0.311 cm³/g,and the average pore size decreased from 10.79 nm to 6.202nm.The adsorption-desorption isotherms before and after activation belong to type IV isotherms.After activation,the fish bone charcoal was mainly mesoporous,with a pore size distribution between 3 nm and 10nm and a pore structure near 3 nm.After activation,the carbon in the fishbone may have a graphite-like structure,and oxygen-containing functional groups such as a phosphate group,a carbonic acid group,and an alcoholic hydroxyl group exist on the surface.?3?The optimized adsorption conditions of activated fish bone charcoal for diesel oil solution were as follows:0.1 g dose,temperature 25°C,salt content 2.5%,solution pH 7,adsorption time 30 min,initial diesel concentration The adsorption capacity of 100 mg/L reached 45.15 mg/g,and the adsorption removal rate was 90.1%.With the increase in the number of repeated use,the adsorption capacity of activated fish bones gradually decreased,and after 6 repeated adsorption tests,the fish bones still had a certain adsorption capacity for diesel.?4?The adsorption process of activated charcoal to diesel oil conforms to the Langmuir adsorption isotherm model.Activated fish bone charcoal is beneficial to the adsorption of diesel molecules,and its adsorption process is mainly physical adsorption.21%of the active adsorption sites have the same energy level,and the attachment process is also affected by adsorption of multiple molecules.?5?The adsorption process of activated charcoal on diesel oil conforms to the second-order kinetic model.The mechanism of sharing or exchanging electrons between the adsorbent and the adsorbate affects the adsorption process to some extent.After activation,the adsorption rate of fish bone charcoal to diesel oil adsorption is faster at the initial stage,and the adsorption rate in the second stage is slower due to adsorption saturation.The thickness of the boundary layer is C₂>C_1.With the increase of adsorption time,the adsorption rate of fish bone char will gradually become slower.Intraparticle diffusion is not the only factor that controls the rate.Adsorption mechanisms such as surface adsorption and liquid mode diffusion also affect the adsorption rate of the process.