高pH条件纳米Fe_3O_4催化H_2O_2分解去除水中4-氯酚

Removal of 4-Chlorophenol with Fe_3O_4 Nanoparticles/H_2O_2 System at High pH

为了克服非均相fenton催化反应中溶液初始pH过低的缺点,开展了pH=5时Fe3O4/H2O2体系催化氧化去除水中4-氯酚实验。试验结果表明:制备的铁氧化物为纯Fe3O4,具有反尖晶石八面体结构。纳米Fe3O4能够高效催化H2O2分解氧化水中的4-氯酚,反应180 min后4-氯酚的去除率达到96.8%。当催化剂投量小于2.0 g/L,4-氯酚的去除率随着催化剂投量的增加而升高;当催化剂投量大于2.0 g/L,去除率会随着投量的增加而降低。随着H2O2投量的增加,4-氯酚的去除率先升高后降低。溶液的初始pH对4-氯酚的去除影响较大,pH越低,去除速率和效率越高。重复使用5次以后,纳米Fe3O4仍然保持较高的催化活性。

In this paper, removal of 4-chlorophenom in aqueous solution with Fe3OJH2O2 system was carried out at pH 5 to evaluate the catalytic efficiency of Fe3O4to H2O2. The results showed that the as-synthesized nanoparticles was pure Fe3O4 and had an inverse spinel structure. Fe3O4 had a high catalytic activity for the H2O2 decomposition to oxidize the 4-chlorophenol in aqueous solution. The removal efficiency of 4-chlorophenol can reached 96.8% after 180 min. When the dosage of Fe3O4 was lower than 2.0 g/L, the removal efficiency of 4-chlorophenol was directly proportional to the dosage of Fe3O4, but inversely to the dosage of Fe3O4 when it was higher than 2.0 g/L. With the increase of the H2O2 dosage, the removal rate of 4-chlorophenol first increased and then reduced gradually. The initial pH of solution had great effect on the 4-chlorophenol removal. The lower pH lead to the higher removal effi- ciency of 4-chlorophenol. The catalytic activity of Fe3O4 was still high after 5 repeated experiments.