Fe^(2+)/HSO_(3)^(-)和Fe^(2+)/S_(2)O_(8)^(2-)体系降解双氯酚酸研究

Study on Diclofenac Degradation by Fe^(2+)/HSO_(3)^(-)and Fe^(2+)/S_(2)O_(8)^(2-)System

研究采用Fe^(2+)/S_(2)O_(8)^(2-)和Fe2+/HSO3-两体系降解水中双氯酚酸(DCF)。结果表明,S_(2)O_(8)^(2-)、HSO_(3)^(-)与催化剂Fe2+的优化摩尔比分别为1:1和10:1,反应5 min,DCF的降解率分别可达90%、100%。在Fe^(2+)/S_(2)O_(8)^(2-)体系中,Cl-可促进DCF降解,富里酸(FA)、草酸跟、柠檬酸根和磷酸根则有轻微抑制作用;而在Fe^(2+)/HSO_(3)^(-)体系中,Cl-对DCF降解有轻微抑制作用,FA和4种常见铁离子配体则呈现明显抑制。SO_(4)^(·-)是两体系的主要活性自由基,Fe^(2+)/HSO_(3)^(-)体系中,SO_(3)^(·-)和SO_(5)^(·-)对DCF的降解也有一定作用。在Fe^(2+)/S_(2)O_(8)^(2-)体系中,几乎无脱氯反应发生;而在Fe^(2+)/HSO_(3)^(-)体系中,则呈现较好的脱氯效率。

The diclofenac(DCF) degradation in water by Fe^(2+)/S_(2)O_(8)^(2-)and Fe^(2+)/HSO_(3)^(-)systems were studied. The results showed that, when the optimal molar ratios of n(S_(2)O_(8)^(2-)): n(Fe^(2+)) and n(HSO_(3)^(-)): n(Fe^(2+)) were 1: 1 and 10: 1, respectively, the degradation rate of DCF in Fe^(2+)/S_(2)O_(8)^(2-)system and Fe^(2+)/HSO_(3)^(-)system was 90% and 100%, respectively. In Fe^(2+)/S_(2)O_(8)^(2-)system, the presence of Cl-could promote the DCF degradation, while fulvic acid(FA),oxalic acid, citrate acid and phosphoric acid had a slight inhibition. In contrast, Cl-had a slight inhibitory effect on DCF degradation in Fe^(2+)/HSO_(3)^(-)system, while FA and the four iron ion ligands showed significant inhibition. SO_(4)^(·-)was the main active radical in both systems, and SO_(3)^(·-)and SO_(5)^(·-)had a certain effect on DCF degradation in Fe^(2+)/HSO_(3)^(-)system. It was observed that there was almost no dechlorination reaction in Fe^(2+)/S_(2)O_(8)^(2-)system,while it showed better dechlorination efficiency in Fe^(2+)/HSO_(3)^(-)processes.