Assessment of a COD analytical method based on the photoelectrocatalysis of a TiO2 nanotube array sensor
Assessment of a COD analytical method based on the photoelectrocatalysis of a TiO2 nanotube array sensor
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DOI：
10.1039/c2ay05940a
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发表时间：
2012-05
影响因子：
3.1
通讯作者：
Hongchong Chen;Jialing Zhang;Quanpeng Chen;Jinhua Li;Di Li;Chaoping Dong;Yanbiao Liu;B. Zhou;S. Shang;W. Cai
中科院分区：
文献类型：
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作者：
Hongchong Chen;Jialing Zhang;Quanpeng Chen;Jinhua Li;Di Li;Chaoping Dong;Yanbiao Liu;B. Zhou;S. Shang;W. Cai
本工作主要描述了一种光电催化方法，以确定化学需氧量（COD）在难降解和低浓度的有机物使用高效的二氧化钛纳米管阵列传感器在薄细胞反应器的评估。使用二十种有机化合物（包括六类顽固有机物）作为模型化合物来评估该方法的准确性。研究了理论需氧量（ThCOD）与响应COD之间的相关性。得到了线性回归方程COD = α × ThCOD，其中α为表示实际COD值与理论值符合程度的回归方程的斜率。结果表明，所有模型化合物的ThOD值与响应COD值具有很好的一致性，α和相关系数r分别为0.9903和0.9901。然而，使用标准重铬酸盐方法的结果显示出较差的一致性，α和r值分别仅为0.8359和0.8213。因此，光电催化法测定难降解低浓度有机物的COD优于重铬酸盐法，具有上级的优点。光电催化法的检测限为0.5 mg L-1，而重铬酸盐COD值低于20 mg L-1时，除糖外，无法准确检测。
This work mainly describes assessment of a photoelectrocatalytic method to determine chemical oxygen demand (COD) in refractory and low-concentration organics using a highly effective TiO2 nanotube array sensor in a thin-cell reactor. Twenty organic compounds, including recalcitrant organics from six categories, were used as model compounds to evaluate the accuracy of the method. The correlation between theoretical oxygen demand (ThCOD) and response COD was studied. The linear regression equation COD = α × ThCOD was obtained, where α is the slope of the regression equation representing the conformity between the actual COD value and the theoretical value. Results of the photoelectrochemical method used in the present paper show excellent conformity between ThOD and response COD for all model compounds, with α and correlation coefficient r values of 0.9903 and 0.9901, respectively. However, results using the standard dichromate method show poor conformity, with α and r values of only 0.8359 and 0.8213, respectively. Hence, we conclude that this photoelectrocatalytic method is superior to the dichromate method for determination of COD in refractory and low-concentration organics. The photoelectrocatalytic method possesses a detection limit of 0.5 mg L−1, while dichromate COD values lower than 20 mg L−1 could not accurately be detected, with the exception of sugars.