pH值對三種活性碳吸附水中鋅離子效能之影響

本研究係以牛糞活性碳、刺竹活性碳與商用活性碳進行水中Zn^(2+)金屬離子之吸附試驗。由結果得知，活性碳之孔隙性質，對於Zn^(2+)吸附性不具影響性，但活性碳界面電位性質，對於Zn^(2+)金屬離子吸附性影響很大，當界面電位為正電位時，活性碳吸附能力不佳，當界面電位低於等電位點時，其吸附性會隨著溶液pH值上升而增加，又在pH7以下鋅金屬水溶液中Zn^(2+)為主要優勢離子，可知當鋅金屬水溶液pH值上升，Zn^(2+)較水中的H^+離子更具有活性碳表面電位點競爭性，且隨著pH值增高活性碳對鋅離子之吸附性更佳，又由吸附重金屬後的XRF分析證實三種活性碳吸附Zn^(2+)後Zn明顯增加，約為吸附前的6～7倍。綜合上述得知，自製牛糞及刺竹活性碳吸附水中鋅金屬的效能類似商用活性碳。

關鍵字

活性碳；吸附；鋅

並列摘要

In this study, adsorption capacity of cattle manure, thorny bamboo (Bambusa stenostachya) activated carbons and commercial activated carbon in zinc ions solution were investigated. The results showed that pore characterization of activated carbon did not affect adsorption of Zn^(2+). On the other hand, zeta potentials of activated carbon mainly affected adsorption capacity of Zn^(2+). When zeta potentials were positive, adsorption capacity of activated carbon was poor. When zeta potentials were below isoelectric point, adsorption capacity of activated carbons increased with increasing pH values in solution. At pH＜7, predominant zinc species was Zn^(2+). Zn^(2+) ions were more competitive than H+ ions on activated carbon surface with increasing pH values in zinc ions solution. The adsorption capacity of Zn^2+ on activated carbon increased with increasing pH values. Furthermore, XRF analysis after absorption of heavy metal indicated increase in Zn after the three activated carbon surface absorbed Zn^(2+). In conclusion, adsorption capacities of zinc ions solution of cattle manure and thorny bamboo activated carbons were similar to commercial activated carbon.

並列關鍵字

Activated carbon ； Adsorption ； Zinc

國際替代計量

pH值對三種活性碳吸附水中鋅離子效能之影響

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