Study On The Extratiom Of Celery Seed Oil And Preparation Of Biochar From Celery Seed Residue And Its Adsorption Properties

Celery seed is taken from the flower of celery and is the fruit of celery.Celery seed essential oil contains a variety of functional components and has rich pharmacological effects.In this paper,the extraction process of celery seed essential oil was optimized,and the effective components of celery seed essential oil were analyzed by GC-MS.Celery seed residue is the waste residue after extraction,which is usually buried and treated,causing environmental pollution.However,celery seed residue has high fiber content and can be used as a good precursor of biochar.In this paper,celery seed residue biochar was prepared and its adsorption performance was investigated.The specific contents are as follows:Firstly,the model of extracting celery seed essential oil by steam distillation was established by response surface methodology,and the extraction process was optimized.The results showed that under the conditions of distillation time 80 min,liquid ratio 7:1 and raw material particle size 60 mesh,the highest oil yield was 0.704%.A total of 43components in essential oil were identified by GC-MS,accounting for97.786%of the total.The main active components were D-limonene,senkyunolide A,NBP,?-seliene,?-pinene,caryophyllene oxide etc.Secondly,biochar was prepared by H₃PO₄ two-step activation and pyrolysis using celery seed residue extracted by steam distillation as precursor.Using response surface methodology and taking methyl blue adsorption value as response value,the optimum conditions for preparing biochar were determined as follows:carbonization temperature 550?,liquid ratio 4:1,and dipping time 6 h.Under these conditions,the maximum adsorption capacity of biochar for methyl blue was 35.1 mg?g^-1.A series of characterization results of the samples before and after modification show that the biochar prepared after modification forms porous rough surface,the specific surface area increases by 15.66 times,the total pore volume and micropore specific surface area increase significantly.There are a large number of active functional groups such as carboxyl,carbonyl,hydroxyl and phosphorus-containing groups such as phosphate ester and phosphate on the surface of biochar.Finally,biochar was used to adsorb phenol and methyl blue to explore its adsorption performance.The experimental results show that the removal rate can reach 71.4%when the initial concentration is 50mg?L^-1,the dosage of phenol is 3 g?L^-1,and the removal rate can reach69.878%when the dosage of methylene blue is 1 g?L^-1.Electron donor-acceptor interaction,hydrogen bonding plays an important role in the adsorption of phenol,and electrostatic attraction,hydrogen bonding plays an important role in the adsorption of methylene blue.The adsorption process of phenol and methyl blue conforms to Freundlich isothermal equation and pseudo-second-order kinetic model,which is favorable for adsorption at higher temperature.Biochar has good affinity for both organic substances.Adsorbed biochar can be desorbed by NaOH,75%ethanol and recycled for many times,further reducing the cost and providing a new way for the utilization of distillation residue.