Study On The Absorption Performance Of Wakame Magnetic Biochar Composite Material To Oil

Crude oil and refined oil leakage is one of the major risks in the process of offshore oil exploration and transportation.Oily pollutants are more and more harmful to the environment and humans.Oily pollutants mainly include crude oil components of alkanes,naphthenes,aromatics and asphaltenes.It is well known that aromatic compounds have strong toxicity and poor biodegradability(such as polyaromatic hydrocarbons),and complex hydrocarbons such as polycyclic isoprenoids are persistent in the environment.These oily pollutants cause serious problems to the animals and plants in the water and people near the waters,and seriously threaten their health and quality of life.The removal and recovery of oily pollutants in water has attracted widespread attention from many scholars.In this study,three activating reagents of H₃PO₄,Zn Cl₂ and KOH were used for one-step pyrolysis to prepare the wakame magnetic biochar composite material.The wakame magnetic biochar composite material obtained by activation of the activating reagent has a good rich pore structure and a large ratio.Surface area.The prepared materials were characterized and analyzed by means of SEM,TEM,BET and XRD.The adsorption of diesel in water was studied,and the adsorption rate,maximum adsorption capacity,adsorption isotherm model,kinetic model,plasmid diffusion model and reusability of the material were evaluated.1.Through BET analysis,it can be known that an appropriate amount of H₃PO₄,Zn Cl₂ and KOH activating reagent can improve the specific surface area and pore structure of the magnetic biochar composite material.The best ratio of wakame to activation reagent is 1:0.5,and the magnetic biochar composite material obtained by KOH activation has the largest specific surface area(824 m²/g),followed by Zn Cl₂activation(455 m²/g),and H₃PO₄ The activated specific surface area(89.5 m²/g)is the smallest.2.SEM can find that the surface of WBPH 0.5 has a"honeycomb"-like regular pore structure;while the surfaces of WBHZ 0.5 and WBPA 0.5 have irregular and fluffy pores and cavities.TEM shows that the surface of all activated wakame magnetic biochar composites has The layer structure is sponge-like with irregular pores.FTIR spectra show that the surface of the wakame magnetic biochar composite material has abundant functional groups(such as-OH,-NH and-CH).XRD can know the successful loading to the wakame magnetic biochar composite material.Raman results show that the activated wakame magnetic biochar composite material has higher crystallinity and graphitization.Elemental analysis shows that the low O/C atomic ratio indicates the high hydrophobicity of the wakame magnetic biochar composite surface.The ICP measurement further clearly knows the content of metallic nickel in the wakame magnetic biochar composite material.3.In the batch adsorption experiment,it is shown that as the diesel oil concentration increases,the adsorption capacity increases,and the time for the reaction to reach equilibrium increases.The increase in the amount of wakame magnetic biochar composite material will increase the adsorption capacity of diesel oil and decrease the removal rate.The optimal dosage is 0.1g.With the increase of temperature,the adsorption of wakame magnetic biochar composite material to diesel oil first increased and then decreased,and the optimal adsorption temperature was 30?.Both acidic environment and alkaline environment are not suitable for the adsorption of wakame magnetic biochar composite material to diesel oil,and the optimal adsorption condition is p H=7.The cycle experiment showed that after the fifth cycle,the adsorption capacity of WBPA 0.5,WBHZ 0.5 and WBPH 0.5 on diesel oil decreased by 3.16%,9.28%and7.27%respectively from the initial adsorption capacity.4.The adsorption isotherm model shows that the Langmuir model fits the experimental equilibrium adsorption data better than the Freundlich model.It can be seen from the adsorption kinetic model that the pseudo-second-order model is more suitable for describing the adsorption system.The intra-particle diffusion model shows that the adsorption process of wakame magnetic biochar composite material to diesel can be considered as a two-step process.The sharp rise in the first stage is the outer surface adsorption stage,and the second stage is the gradual adsorption stage,the rate of which is controlled by the diffusion within the particles.