Synthesis Of Fe-based Nanopartical@Seabuckthorn Branches Biocarbon Composites And Their Wastewater Treatment Performance Study

Activated carbon adsorption is a wastewater treatment method which is widely used in the removal of contaminants.But the high cost of commercial activated carbon increase the operating cost of wastewater treatment.Therefore,the preparation of activated carbon using agricultural biomass waste has widely caused the public concern.Seabuckthorn is a kind of deciduous shrubs,distributing widely in high altitude area.However,in the picking process of sea buckthorn fruit,generated seabuckthorn branches has caused a series of environmental pollution problems because they were discarded or on-site incineration recklessly.Seabuckthorn branches,as a typical carbon-rich,cheap,and abundant agricultural solid waste resources,is a kind of natural source biological carbon which can be used for the activated carbon preparation of low-cost,suitable and sustainable production.But a single Seabuckthorn branches biocarbon adsorption cannot achieve the low cost,high efficiency and no secondary pollution,etc.Therefore,the iron-based nano particles were introduced into the surface of seabuckthorn branch carbon,increasing the specific surface area to improve the performance of adsorption,and building up the heterogeneous Fenton system in order to realize the adsorbent recycling,prevent secondary pollution and further reduce the cost.The novel compound adsorption material was obtained.Such compound adsorption materials were applied in the field of antibiotic wastewater and dye wastewater treatment,and the adsorption/regeneration performance of the composite materials were investigated.The concrete research content is as follows:?1?The abandoned seabuckthorn branches impregnated with Fe3+ were used to prepare the composite adsorbents of Fe₃O₄@seabuckthorn branches biocarbon by the thermal cracking method.SEM and EDS ascertain that the size of Fe₃O₄ nanoparticles is about 40 nm,partially covered on the surface of carbon matrix,and presented good monodisperse and isolated island state.XRD indicate that the generated Fe₃O₄ nanoparticles are face-centered cubic crystalline,while seabuckthorn branches carbon is amorphous.As the treatment goal,doxycycline wastewater was managed and factors affecting the adsorption process,such as pH,doxycycline concentration and time were investigated,respectively.The adsorption performance was investigated by analyzing the adsorption kinetics,isotherm models and adsorption thermodynamics.The results show that under the condition of alkaline,Fe₃O₄@seabuckthorn branches biocarbon has a good adsorption capacity.The adsorption of doxycycline by Fe₃O₄@ seabuckthorn branches biocarbon was found to be in better correlation with the Freundlich isothermal model and pseudo-second-order kinetic equation.Reaction is spontaneous and endothermic,and the process is dominated by chemical absorption and physical adsorption simultaneously.Seabuckthorn branches loaded with iron were applied to the treatment of doxycycline wastewater.In the presence of H₂O₂,heterogeneous Fenton system was generated,and thus Fe₃O₄ and H₂O₂ realized the regeneration of the adsorbent.?2?Fe₃O₄@seabuckthorn branches biocarbon composite adsorbents were prepared through one step thermal cracking method.XRD and SEM were used to characterize the structure and the magnetism was also detected.The results show that seabuckthorn branches carbon belongs to amorphous,whereas Fe₃O₄ nanoparticles are face-centered cubic crystalline with 41 nm particle size,and the Fe₃O₄ nanoparticles present isolated island state on the surface of seabuckthorn branches biocarbon.The macroscopic magnetic of Fe₃O₄@seabuckthorn branches biocarbon composite adsorbents have been endowed due to the attachment of Fe₃O₄ nanoparticles.Then,the adsorption model of methylene blue through Fe₃O₄@seabuckthorn branches biocarbon composite adsorbents within the fixed bed reactor are established by using the BBD type of response surface method,and their response surface are analyzed further.It has been verified that the mode of above-presented can accurately describe the process of adsorption.Thereinto,the concentration of methylene blue,pH,flow rate,square of concentration and the square of pH effect is remarkable.With the decrease of the flow rate and concentration,increase of the pH,the removal rate can be enhanced.The regeneration experiments of Fe₃O₄@seabuckthorn branches biocarbon composite adsorbents show that the heterogeneous Fenton oxidation can effectively realize the regeneration and recycle,and the regeneration mechanism was discussed aslo.?3?Akaganeite??-FeOOH?nanoparticles were successfully anchored on the surface of porous seabuckthorn branches biocarbon via a simple low-temperature hydrothermal process without use surfactants.The ?-FeOOH@seabuckthorn branches biocarbon composite was characterized by X-ray diffraction?XRD?,scanning electron microscopy?SEM?,and energy dispersive spectrometry?EDS?.On the basis of characterization methods,a possible mechanism of formation of the ?-FeOOH@seabuckthorn branches biocarbon composite was discussed.The ?-FeOOH@seabuckthorn branches biocarbon composite was used in fixed-bed columns for the effective removal of doxycycline from an aqueous solution.The effects of inlet doxycycline concentration?22-32 mg·L-1?,feed flow rate?1-3 mL·min-1?,?-FeOOH@seabuckthorn branches biocarbon bed depth?0.7-1.5 cm?and pH?2-11?on the adsorption breakthrough profiles were investigated.It was simulated by the Thomas and Yoon-Nelson models at different conditions.The bed of ?-FeOOH@seabuckthorn branches biocarbon saturated with doxycycline was readily regenerated,in situ,by a heterogeneous Fenton-like oxidation reaction.The synergistic effect resulting from the biosorption nature of seabuckthorn branches biocarbon and the catalytic oxidation properties of the supported ?-FeOOH nanoparticles results in a new promising composite material for water treatment and purification.