钙钛矿型催化剂催化湿式氧化处理煤气化废水纳滤浓缩液

Treatment of nanofiltration concentrate of coal gasification wastewater by catalytic wet oxidation with perovskite structure catalysts

采用溶胶-凝胶法制备了Mn掺杂钙钛矿型催化剂La Fe_xMn_(1-x)O_3,并以其为催化剂催化湿式双氧水氧化处理煤气化废水纳滤浓缩液。采用XRD,SEM,FTIR技术对催化剂进行了表征。表征结果显示:制备的催化剂均具有标准的钙钛矿型结构,其中,La Fe_(0.9)Mn_(0.1)O_3的结构稳定,比表面积大。实验结果表明:制备的催化剂中La Fe_(0.9)Mn_(0.1)O_3的催化活性最高,且稳定性好,连续使用5次后催化活性未见明显减弱;在H2O2投加量3.0 g/L、n(H_2O_2)∶n(La Fe_(0.9)Mn_(0.1)O_3)=12∶1、反应温度160℃、反应压力1 MPa、浓缩液pH 3、反应时间60 min的最优条件下,COD、UV254和TOC的去除率分别达到80.9%、95.2%和68.0%,BOD5/COD由0.02提升至0.40,可生化性大幅提高。

The Mn-doped perovskite structure catalysts LaFexMn1-xO3 were prepared by sol-gel method and used as catalysts to treat nanofiltration concentrate of coal gasification wastewater by catalytic wet peroxide oxidation. The catalysts were characterized by XRD,SEM and FTIR. The characterization results showed that the catalysts had standard perovskite structure,and LaFe0.9Mn0.1O3 had the better structure stability and larger specific surface area. The experimental results indicated that：LaFe0.9Mn0.1O3 had the best catalytic activity and stability,and its catalytic activity was not significantly decreased after 5-time reusing;Under the optimum conditions of H2O2 amount 3.0 g/L,n（H2O2）∶n（LaFe0.9Mn0.1O3）=12∶1,reaction temperature 160 ℃,reaction pressure 1 MPa,concentrate pH 3 and reaction time 60 min,the removal rate of COD,UV254 and TOC reached 80.9%,95.2% and 68.0%,respectively,BOD5/COD was increased from 0.02 to 0.40,indicating that the wastewater biodegradability was significantly improved.