研究生答辩ppt 模板 实例 科技论文汇报模板Adsorptive removal of As(V) and As(III).ppt

Adsorptive removal of As(V) and As(III) from waterby a Zr(IV)-loaded orange waste gel Biplob Kumar Biswas Journal of Hazardous Materials 154 (2008) 1066–1074 Abstract Orange waste has been loaded with zirconium(IV) so as to examine its adsorption behavior for both As(V) and As(III) Adsorption kinetics Effect of pH on the adsorption of arsenic(V and III) Effect of foreign anions Adsorption isotherm Column adsorption and elution tests Instruction Preparation of the SOW gel Crush into small particles Str for certain time Washed until neutral pH Mix refrigerated orange waste Ca(OH)2 water Dry The specific surface area:7.25 m2/g average pore diameter:14.3 nm Preparation of the Zr(IV)-loaded SOW gel 3 g of the SOW gel 0.1 M zirconium Equilibrated at Ph=2.11 filtered washed until neutral pH Dry in vacuo until constant weight sieved to obtain a particle size fraction of between 75 and 150 nm Batch-wise adsorption tests Condition 30?C at 140 rpm for 24 h 25 mg (dry weight) of the gel 15 ml of the arsenic solution. arsenate and arsenite in the concentration range 5–900 mg/l initial arsenic concentra-tion for pH test 20 mg/l Ph for isothem experiment 3 and 10 for As(V) and As(III) Kinetic studies Fig. 2. The effect of pH on Zr(IV) adsorption onto the SOW gel Fig. 3. Effect of contact time and concentration on the adsorption of arsen-ate onto the Zr(IV)-loaded SOW gel. the adsorption kinetics at four different concentrations could be best explained in terms of the pseudo-second-order rate equation with respect to adsorption capacity and correlation coefficients Fig. 4. The effect of pH on the adsorption of (○) As(V) and (●) As(III) onto the Zr(IV)-loaded SOW gel and leakage of Zr(IV) during (□) As(V) and (■) As(III) adsorption Scheme 1. Inferred mechanism of ligand exchange for arsenic adsorption onto the Zr(IV)-loaded SOW gel. Fig. 5. Effect of other anions on As(V) removal Fig. 6. Adsorption isotherms for As(V) and As(III) onto the Zr(IV)-loaded SOW gel