Removal of Perchlorate by Zero-valent Magnesium and Cu/Mg Bimetallic Particles
|關鍵字:||過氯酸鹽;零價鎂;銅鎂雙金屬;開放系統;等溫吸附;adsorption isotherm;Cu/Mg bimetallic particles;open system;perchlorate;zero-valent magnesium||公開日期:||2008||摘要:||過氯酸鹽 (ClO4-) 已經被美國環保署認定為新興污染物之一，本研究使用零價鎂 (Mg0) 及銅鎂 (Cu/Mg) 雙金屬於開放系統中去除水中過氯酸鹽，實驗變數包括銅之來源、負載比例、加藥量、初始濃度、反應溫度等，探討各條件對過氯酸鹽去除率之影響，並以中間產物氯酸鹽 (ClO3-) 及亞氯酸鹽 (ClO2-) 為反應物，探討過氯酸鹽與銅鎂雙金屬之反應途徑。批覆銅之來源有硝酸銅 (Cu(NO3)2)、氯化銅 (CuCl2) 及硫酸銅 (CuSO4) 三種，實驗結果顯示，以硝酸銅為批覆銅之來源時，20% Cu/Mg雙金屬與過氯酸鹽反應之過氯酸鹽去除率 (76%) 為最佳，而最適之加藥量為20 g/L，過氯酸鹽濃度於反應時間1分鐘內，瞬間降低，但中間產物氯酸鹽及亞氯酸鹽均未被偵測到，最終產物氯離子 (Cl-) 濃度亦沒有隨之增加，等溫吸附實驗之結果顯示，Langmuir及Freundlich模式皆可適用，因此，反應初期主要之去除機制為吸附作用。
Perchlorate (ClO4-) has been identified as an emerging contaminant by U.S. EPA. In this study, zero-valent magnesium and Cu/Mg bimetallic particles were used to remove perchlorate in open system. Source of Cu, loading ratio, dosage, initial concentration, and temperature were considered variables during the experiments to investigate the effects of the different conditions on perchlorate removal rate. In addition, intermediate, chlorate (ClO3-) and chlorite (ClO2-), were as reactants to investigate the pathway of the reactions of perchlorate with Cu/Mg bimetallic particles. The loading source of Cu were from Cu(NO3)2 , CuCl2, and CuSO4. The experiments suggested that the highest removal rate, 76%, was achieved by 20% Cu/Mg bimetallic particles loaded from Cu(NO3)2 and 20 g/L was the optimal dosage. However, the initial rapid drop of perchlorate within 1 minute was not matched by an immediate increase in chloride (Cl-) concentration. Intermediate, chlorate and chlorate, were also undetected. The adsorption experiment data have good fit for both Langmuir and Freundlich adsorption isotherm. Therefore, adsorption were considered the primary removal mechanism in the beginning of the reactions.
在 IR 系統中的文件，除了特別指名其著作權條款之外，均受到著作權保護，並且保留所有的權利。