燃煤飛灰其顆粒細緻,具較大的比表面積,應可作為水中污染物之吸附劑,釵h學者已經證實應用燃煤飛灰做為吸附劑之可行性,但因飛灰產生條件及吸附實驗參數條件等因子,導致吸附水中污染物之去除效率差異頗大。然而文獻中尚無相關論著針對飛灰礦物組成對水中有機物吸附關係進行整體性探討,為充分釐清飛灰之礦物組成對其去除水中有機物之影響。
本研究採取台灣電力公司興達、大林等火力發電廠具代表性之燃煤飛灰作為研究用之吸附劑,進行水中腐植酸、2,4-二硝基硝酚、苯胺之恆溫吸附實驗,將恆温吸附實驗結果所得單位吸附量作為應變數,以飛灰礦物組成分析結果作為自變數,藉多元線性迴歸探討飛灰礦物組成對水中有機物吸附之影響,並建立不同礦物組成燃煤飛灰吸附水中有機物單位吸附量之預測模方程式,提供燃煤飛灰作為水中污染物吸附劑選擇之參考。
研究結果發現,燃煤飛灰之礦物組成中對水中有機物具不同之貢獻度,預測模式如下:
在飛灰吸附腐植酸吸附方面,藉多元線性迴歸所建立之以礦物組成預測製備飛灰對腐植酸之單位吸附量Q(mg-humic acid/ g-fly ash)=(0.438×CSi+0.339×CAl+0.674×CFe -0.097×CCa+0.882× CMg+0.441×COt);藉多元線性迴歸所建立之以礦物組成預測實廠飛灰吸附腐植酸單位吸附量Q(mg-humic acid/g-fly ash)=(-0.093×CSi+0.806×CAl+1.302×CFe+0.434×CCa+4.334× CMg+0.380×COt);在苯胺吸附方面,藉多元線性迴歸所建立之以礦物組成預測製備飛灰吸附苯胺之單位吸附量Q(M-aniline/ g-fly ash)=(2.08×10-6×CSi+2.24×10-6×CAl+5.35×10-6×CFe -1.03×10-5×CCa+5.23×10-6× CMg+3.31×10-6×COt);藉多元線性迴歸所建立之以礦物組成預測實廠飛灰吸附苯胺單位吸附量Q(M-aniline/g-fly ash)=5.60×10-6×CSi-6.00×10-6×CAl+2.53×10-5× CFe-7.25×10-6×CCa-4.19×10-5× CMg+6.83×10-7×COt);在2,4二硝基酚方面,藉多元線性迴歸所建立之以礦物組成預測製備飛灰吸附2,4二硝基酚之單位吸附量模式為Q(M-2,4-dintrophenol/g-fly ash)=6.32×10-7×CSi-4.18×10-7×CAl+5.93×10-7× CFe +1.59×10-7×CCa+1.62×10-6× CMg+7.99×10-6×COt);藉多元線性迴歸所建立之以礦物組成預測實廠飛灰吸附2,4-二硝基酚單位吸附量Q=8.25×10-7×CSi-1.06×10-6×CAl -3.87×10-6×CFe +2.86×10-7×CCa+1.70×10-5× CMg+1.87×10-6×COt);本研究所建立之燃煤飛灰於特定條件下對水中腐植酸、2,4-二硝基硝酚、苯胺單位吸附量預測模式可提供做為選擇燃煤飛灰作為水中有機物吸附劑之參考。 In this study, coal fly ash from coal-fired power plant was used to remove aqueous organic pollutants. Effects of fly ash mineral composition (e.g. SiO2、Al2O3、Fe2O3、CaO、MgO, Other) on adsorption of humic acid 、aniline、2,4-dinitrophenol from aqueous solution was discussed.The adsorption isotherm experiments were conducted to obtain the specific adsorption capacities of organic compounds .Finally, prediction models of organic specific compounds adsorption capacity onto fly ashes with various minerals composition were developed by multiple liner regression. The prediction models developed in this study can be helpful for the selection of coal fly ash as the adsorbent of organic compounds from aqueous solution.
Research results demonstrates, the prediction model of specific adsorption capacity of humic acid removed by the coal fly ash made laboratory is Q(mg-humic acid/ g-fly ash)=(0.438×CSi+0.339×CAl+0.674×CFe -0.097×CCa+0.882× CMg+0.441×COt); the prediction model of specific adsorption capacity of humic acid removed by the coal fly ash from coal-fired power plant is Q(mg-humic acid/ g-fly ash)=(-0.093×CSi+0.806×CAl+1.302×CFe+0.434×CCa+4.334× CMg+0.380×COt);fly ash mineral composition on adsorption of aniline,the prediction model of specific adsorption capacity of aniline removed by the coal fly ash made laboratory is Q(M-aniline/g-fly ash)=(2.08×10-6×CSi+2.24×10-6×CAl+5.35×10-6×CFe -1.03×10-5×CCa+5.23×10-6× CMg+3.31×10-6×COt);the prediction model of specific adsorption capacity of aniline removed by the coal fly ash from coal-fired power plant is Q(M-aniline/g-fly ash)=5.60×10-6×CSi-6.00×10-6×CAl+2.53×10-5× CFe-7.25×10-6×CCa-4.19×10-5× CMg+6.83×10-7×COt);fly ash mineral composition on adsorption of 2,4-Dinitrophenol, the prediction model of specific adsorption capacity of 2,4-dinitrophenol removed by the coal fly ash made laboratory is Q(M-2,4-dintrophenol/ g-fly ash)=6.32×10-7×CSi-4.18×10-7×CAl+5.93×10-7× CFe +1.59×10-6×CCa+1.62×10-6× CMg+7.99×10-7×COt);the prediction model of specific adsorption capacity of 2,4-dinitrophenol removed by the coal fly ash from coal-fired power plant is Q(M-2,4-dintrophenol/g-fly ash)=8.25×10-7×CSi-1.06×10-6×CAl -3.87×10-6×CFe +2.86×10-7×CCa+1.70×10-5× CMg+1.87×10-6×COt).