Preparation Of Mushroom Resdue Activated Carbon And Its Removal Of Cr(?) And Aniline From Water

China is the world's largest producer of edible fungi.Since 2013,the output has exceeded 30 million tons.Mushroom Residue(MR)is the medium waste that remains after harvesting the product during the cultivation of the edible fungus.At present,MR has not been scientifically and effectively utilized,resulting in numerous problems such as resource waste and environmental pollution that hinder the cultivation of edible fungi;if these problems cannot be solved in time,it is easy to cause a vicious circle.The use of MR to prepare activated carbon for the adsorption and removal of Cr(?)and aniline in water not only solves the problem of MR pollution,but also prolongs the biological circulation chain,reduces the environmental pollution of Cr(?)and aniline in water,and improves the economic,social and ecological benefits of agricultural production.In this paper,mushroom residue activated carbon(MRAC)was prepared by Zn Cl2 activation method to remove Cr(?)from water.The optimal preparation conditions for MRAC were as follows: impregnation ratio 1:1,carbonization temperature 200 °C,carbonization time 1 h,activation temperature 700 °C,activation time 2 h.The MRAC is modified by KMn O4 to form manganese-loaded activated mushroom residue activated carbon(Mn-MRAC)for removing aniline from water.The optimum modification conditions for Mn-MRAC were as follows: KMn O4 solution concentration 0.04 mol/L,calcination temperature 450 °C,calcination time 1 h.The characterization of MRAC and Mn-MRAC prepared under optimal conditions was carried out by FTIR,BET,SEM and EDS.The characterization results of MRAC are as follows: FTIR indicates that MRAC has abundant surface functional groups,BET indicates that the specific surface area of MRAC is as high as 857.14 m2/g,SEM indicates that a large number of uniform microporous structures are distributed on the surface of MRAC,and EDS indicates that elements are generated before and after adsorption of Cr(?)by MRAC.The Mn-MRAC characterization results show that compared with MRAC,the number of oxygen-containing functional groups and micropores on the surface of Mn-MRAC is increased,the surface is smoother,the pores are more abundant and the distributed load is more uniform,The MnMRAC elements change before and after adsorption of aniline.Study on impacts of p H,reaction temperature,MRAC/Mn-MRAC dosage,reaction time,initial concentration of Cr(?)/aniline in solution,inorganic anions and small organic molecules to remove Cr(?)/aniline from MRAC/Mn-MRAC.The experimental results show that the optimum reaction conditions for removal of Cr(?)from water by MRAC are: p H 7,reaction temperature 25 °C,MRAC dosage 0.5 g,reaction time 120 min,Cr(?)solution 50 mg/L;The best reaction conditions under study for the removal of aniline from water by MnMRAC are: p H 7,reaction temperature 25 ?,Mn-MRAC dosage 0.2 g,reaction time 120 min,initial concentration of aniline solution 10 mg/L.Under the optimal reaction conditions,the removal rates of Cr(?)and aniline in water by MRAC and Mn-MRAC were up to 99.98% and 99.7%,respectively.The treated water quality met the "Emission Standards for Pollutants in Municipal Wastewater Treatment Plants"(GB18918-2002).The adsorption of Cr(?)in water by MRAC follows the quasi-secondary kinetic model;and it conforms to the Langmuir model,which belongs to monolayer adsorption,and the adsorption reaction is endothermic.The higher the reaction temperature,the higher the reaction spontaneousness.The removal rate of Cr(?)in water after MRAC was desorbed by HCl for 5 times was higher than 88%.The adsorption of aniline by Mn-MRAC follows the quasi-secondary kinetic model;it conforms to the Langmuir model and belongs to the monolayer adsorption.The adsorption reaction is an exothermic reaction,and the temperature is reduced,and the reaction is more spontaneous.