| The adsorption of Cu2+,Pb2+,Cd2+ on humic acid HA,fulvic acid FA with the major components of soil (humic acid HA, fulvic acid FA), and the experimental conditions (temperature,pHvalue) was changed, in the end, A experiment was conducted to study the competitive adsorption of three metals on humic acids with the three metals'background level in the soil,the result shows that:(1)In the separation and purification of humic acids,the performance of HA for easy extraction and a large amount, but FA extraction of smaller, and the carbon content less than HA;(2)pH impacts the adsorption of three metals on HA,FA mostly,adsorptive capacity With pH value being proportional, up to a certain scope no longer to increase, the bound of HA and FA are 4.5,4.0,5.2 and 4.8,5.0,5.5。the adsorption rule is approximately similar of the Cu2+,Pb2+,Cd2+ on HA to FA;(3)Temperature affects the adsorption of Cu2+,Pb2+,Cd2+ on HA,FA also,absorption rate with temperature being reverse proportion the rule of adsorptive capacity is also,the influence rule presents the similar tendency;(4)The adsorption of Pb2+,Cu2+ on HA,FA is stronger than Cd2+, the adsorption order is Pb2+>Cu2+>Cd2+, and the best equation of Pb2+> Cu2+> Cd2+on HA is Langmuir (R2=0.9939,0.9925,0.9910),Temkin is the secondly (R2=0.9798,0.9765,0.9347),Freundlich is a little bad (R2=0.9222,0.8400,0.9480), as for adsorption of Pb2+> Cu2+> Cd2+on FA,Langmuir is the best equation (R2=0.9943,0.9786,0.9767),but Freundlich is the secondly (R2=0.9901,0.9786,0.9478),Temkin is a little bad (R2=0.9031,0.9352,0.8815);(5)The adsorption of Pb2+,Cu2+ on HA,FA are affected by competing ions,adsorptive capacity deserved compared to the sole ion's , the performance of adsorptive capacity different reduction,but in terms of competing adsorption of Cu2+ and Cd2+,promoted the absorption of Cu2+ along with Cd2+, possibly because of competing for "the adsorption place",thus displays the different selective adsorption of three kind of ions。... |
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