| Blast furnace slag is the waste which is produced in the process of the ironmaking,because of the huge amount of blast furnace slag and its related processing cost, it isnecessary for us to use blast furnace slag adsorbent in the application of heavy metalwastewater treatment. In this paper，blast furnace slag was used as adsorbent, blast furnaceslag dried after it washed with deionized water, then grinded by a ball mill, in the end,screened by screening mesh product, and represented materials by technology of SEM,BET, FTIR and ICP. The influence of adsorbent dosage, adsorption time, adsorptiontemperature, pH value and initial mass concentration of solution on absorption efficiencyof Cu2+, Cd2+, Zn2+was investigated in this study, optimum technological conditions weredetermined by orthogonal test method, studied on the competitive adsorption experimentsof Cu2+, Cd2+, Zn2+, then further studied on the adsorption mechanism of adsorbing Cu2+,Cd2+, Zn2+on blast furnace slag, the results of the study was as follows：(1)Through the single factor experiment of Blast furnace slag adsorbed Cu2+and Cd2+,Zn2+, the result shows that blast furnace slag has a very good adsorption of Cu2+, Cd2+, Zn2+,removal rate can reach99%. By orthogonal experiment, indicates that the main factorsaffecting the adsorption of Cu2+on blast furnace slag is the temperature, followed byoscillation time, then for the blast furnace slag dosage, finally for the pH value. The mainfactors affecting the adsorption of Cd2+on blast furnace slag is the pH value, followed bythe temperature, then for the blast furnace slag dosage, finally for oscillation time. Themain factors affecting the adsorption of Zn2+on blast furnace slag is the pH value,followed by the blast furnace slag dosage, then for the temperature, finally for oscillationtime.(2)By competitive adsorption experiments, three kinds of metal ions adsorptionbehavior in blast furnace slag is mutual inhibition, choose order of blast furnace slagabsorbed Cu2+, Cd2+, Zn2+is Cu2+＞Cd2+＞Zn2+. (3)Through the mechanism experiments of adsorption, the main process of Cu2+, Cd2+,Zn2+in blast furnace slag is particle diffusion process, adsorption form conforms to themonolayer adsorption, adsorption process is spontaneous, endothermic and entropy, thephysical adsorption process and it is easy to happen, main force is hydrogen bonding forceand accidentally electrode reaction.The above results show that blast furnace slag as a kind of sorbent used in heavymetal wastewater treatment, has a very good adsorption properties for heavy metal ions. |
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