Fe-Mn-MCM-41分子筛催化臭氧氧化控制含溴水中溴酸盐的生成

Bromate Inhibition of Bromide-Containing Water during Catalytic Ozonation with Fe-Mn-MCM-41

  • 摘要: 采用水热法合成铁、锰双金属掺杂MCM-41(Fe-Mn-MCM-41),并将其用于控制催化臭氧氧化含溴水体中溴酸盐,研究了初始pH、叔丁醇(TBA)、磷酸盐等对溴酸盐抑制效果的影响. 结果表明,当溶液初始pH为5.0~9.0时,溴酸盐生成量随pH值升高而增加, pH = 5.0时催化剂对溴酸盐的抑制率达到85.9%.叔丁醇(TBA)的加入使单独臭氧氧化与催化臭氧氧化中溴酸盐生成量明显降低,当加入0.1 mM TBA后,溴酸盐分别减少67.7%和81.1%. 磷酸盐的加入(1、5、10 mg/L)会降低溴酸盐生成量,当加入1 mg/L磷酸盐时,单独臭氧氧化与催化臭氧氧化两种体系中,溴酸盐抑制率分别达到29.6%和82.5%. 此外,还研究了体系中生成的HOBr与H2O2浓度,结果表明,单独臭氧氧化中次溴酸浓度高于催化臭氧氧化过程,说明催化臭氧氧化过程是通过阻止Br-氧化生成HOBr/OBr-抑制溴酸盐生成; Fe-Mn-MCM-41/O3中的H2O2浓度高于O3过程,而H2O2是一种溴酸盐抑制物,证明了催化剂的加入可以提高对溴酸盐的抑制率. 因此,Fe-Mn-MCM-41是一种可用于控制含溴水体中溴酸盐生成的臭氧氧化催化剂.

     

    Abstract: Employed bimetallic MCM-41 (Fe-Mn-MCM-41) synthesized by hydrothermal method to control bromate formation during ozonation of bromide-containing water. The influences including initial pH、t- butanol (TBA) and phosphate were investigated in this paper. The results showed that bromate formation increased with the increased pH in the range of 5.0-9.0, bromate inhibition efficiency for Fe-Mn-MCM-41 achieved 85.9% at pH 5 during catalytic ozoantion process. Bromate decreased in the presence of t- butanol (TBA) during both O3 and Fe-Mn-MCM-41/O3, suppression efficiency for bromate were 67.7% and 81.1% when adding 0.1 mM TBA. The addition of phosphate (1、5、10 mg/L) decreased bromate formation during ozonation and catalytic ozonation. Bromate decreased to 29.6% and 82.5% in O3 and Fe-Mn-MCM-41/O3 in the presence of 1 mg/L phosphate. Additionally, the concentration of HOBr and H2O2 were tested. Compared with ozonation process, the concentration of HOBr in catalytic ozonation was lower. The results showed that Fe-Mn-MCM-41 could prevent the production of HOBr to inhibit bromate formation. Besides, H2O2 is an inhibitor for bromate, more H2O2 was found in Fe-Mn-MCM-41/O3 rather than O3 process, it implied that Fe-Mn-MCM-41 enhanced the inhibition efficiency for bromate. Therefore, Fe-Mn-MCM-41was a catalyst which could decreased the bromate formation of bromide-containing water during catalytic ozonation process.

     

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