Research On The Preparation Method And Adsorption Of Arsenic(?)in Wastewater By Modified Bamboo Charcoal

With the development of modern industry,arsenic polluted wastewater has becoming an urgent environmental problem worldwide.Among numerous technologies removing arsenic from aqueous solution,the adsorption method has attracted scholar's extensive attention due to its fast adsorption rate,low cost and simple operation.Biochar is an environmentally friendly adsorbent.However,the adsorption capacity of pure biochar is limited,and it's difficult to separate and recycle from aqueous solution.In this study,bamboo charcoal was prepared by carbonization of bamboo at high temperature,and a new magnetic bamboo charcoal composite(MBBC@SDD)was prepared by changing the pore structure and the number of functional groups on the surface by modification.A series of characterization analysis were performed to study the morphological structure,adsorption mechanism and reusability.The main conclusions are as follows:(1)The preparation technology of MBBC@SDD was studied.MBBC was prepared from bamboo charcoal pyrolyzed at 600? and the addition of iron ions when the mass ratio of iron carbon was 1:2,then it used to prepare MBBC@SDD.(2)SEM-EDX,FTIR,XPS and TG were used to characterize the properties of bamboo charcoal before and after modification.The results showed that the number of oxygen-containing functional groups on the surface of the modified material increased,and new functional groups such as N-C=S and Fe-O were introduced.It is shown that Fe3O4 pellets at 100-300 nm were evenly distributed on the surface of MBBC@SDD.(3)The influence factors,isotherms and kinetics of MBBC@SDD on arsenic adsorption were studied.Shows the optimal adsorption conditions for As(?)by MBBC@SDD were dosing quantity 2.5 g/L,pH value 5.0,adsorption time 2 h,temperature 40?.MBBC@SDD saturated adsorption capacity is 98.63 mg/g,and BBC saturated adsorption capacity is 15.03 mg/g.It is obviously that modification significantly improved the effect of bamboo charcoal adsorption of As(?).(4)The regeneration and recycling of MBBC@SDD was studied.The results showed that it has good adsorption capacity after 5 cycles of recycling.It revealed that MBBC@SDD has good reuse and regeneration stability.(5)As(?)-Pb(?)and As(?)-Pb(?)binary ion system competitive adsorption experiments show that MBBC@SDD has adsorption selectivity for As(?)and low adsorption ability for Pb(?)?Zn(?)(6)The adsorption mechanism of arsenic by MBBC@SDD was studied.The adsorption process conforms to the pseudo-second-order kinetic model,and the adsorption isotherm fitting conforms to the Langmuir model.The adsorption rate control procedure is a single layer adsorption model based on chemical reaction.It is shown that chemisorption is the main adsorption process,electrostatic interaction,ion exchange and functional group complexation are the main adsorption mechanisms.The polar functional groups Fe-O,N-C=S,-OH significantly improved the adsorption of As(?).