泛用型電流式自由氯感測系統之開發

Abstract

本研究成功開發一套泛用型自由氯感測系統，適用於不同酸鹼值與電導度的溶液。使利用未修飾的之金電極透過還原電流量測自由氯濃度。首先使利用循環伏安法量感測在0.1 M NaCl為背景且酸鹼值為5.5之次氯酸鈉水溶液，其中電流密度峰值與自由氯濃度之關係成正比，線性範圍為自由氯89.3 ~ 653.3 mg/L。其次再者，使利用安培分析法感量測次氯酸鈉水溶液之自由氯濃度，其感測之還原電流密度與自由氯濃度在9 ~ 930 mg/L範圍內具有良好的線性關係（R2 > 0.996）與再現性（%RSD < 4.5），且其偵測下限為4.5 mg/L。，另外本研究也討論還原電流密度隨著不同酸鹼值與氯離子濃度的變化。 本研究依上述基礎理論開發一套泛用型自由氯感測系統，此系統包括溫度感測、酸鹼值感測、電導度感測及自由氯感測，並且實際應用於電解水產製設備中用來量測自由氯濃度。自由氯感測時間為30秒，恢復時間為120秒，而自由氯濃度感測範圍為10 ~ 800 mg/L，適用之酸鹼值與電導度的範圍分別為5.5 ~ 9與5 ~ 20 mS/cm。

A generic free available chlorine (FAC) monitoring system was developed in this study. The determination of free available chlorine (FAC) concentration through reduction current usingat a bare gold electrode has been demonstrated. By using cyclic voltammerty, we discovered a linear relationship between reduction peak current and FAC concentration was achieved in the range of 89.3-653.3 mg/L at pH 5.5 in 0.1 M NaCl as supporting electrolyte. Furthermore, amperometric determination of FAC performed a linear range of 9-930 mgL-1 (R2 >0.996), a good reproducibility (%RSD <4.5) and the detection limit of 4.5 mg/L. The influence on We also considered the change of reduction current density due to the variation of with different pH and chloride ion concentration was investigated. TheA generic free chlorine monitoring system developed based on this study has been developed. The system was equipped with a temperature sensor, a pH sensor, an EC sensor, and a FAC sensor, and was successfully implemented applied within an to detecting FAC in electrolyzed water generating system to detect FAC concentration. The analysis time and a recovery time required are 30s and 120s, respectively. The system achieved to detect FAC concentration of 10 ~- 800 mg/L in the pH range from 5.5 to 9 as well as EC range from 5 to 20 mS/cm.