微电解-电/Fenton-曝气池工艺预处理高浓度亚麻废水

高浓度亚麻废水不宜直接进行生化处理。试验采用"Fe-C柱微电解-电/Fenton-曝气池"工艺对其进行预处理,即先采用Fe/C微电解,然后基于Fe2+的生成几乎同步引入电/Fenton反应,之后再调节流出液pH至碱性并鼓入空气以除去部分NH3-N。相应优化工艺条件为:Fe/C柱微电解时mFe/mC为2:1,废水停留时间为1.5 h;电/Fenton时双氧水(30%)滴加速度为0.025 mL/min;调节水样pH10并在空气流速为1.5 L/min的条件下空气吹脱1.5 h。采用该工艺预处理高浓度亚麻废水后,出水几乎为无色;固体悬浮物的去除率可达94.2%,NH3-N去除率可达71.4%,COD去除率可达51.8%,BOD5去除率可达28.3%,为后续生化深度处理创造了有利条件;BOD5/COD值由原来的0.12上升至0.19,废水的可生化性得到较明显的改善。电/Fenton反应的处理效果好于普通的Fenton反应,其原因可能是由于电/Fenton既有"原位"的均相/非均相Fenton反应发生,又有在微电解电场协助下的"电催化Fenton"反应发生。

Pretreatment of Fiber Flax Wastewater with High COD by Microelectrolysis,Electro-Fenton and Aeration Tank Process

Fiber flax wastewater with high COD is not suitable for direct biochemical treatment.Microelectrolysis,electro-Fenton and aeration tank process were applied to pretreat the raw wastewater under the optimum technological conditions of mass ratio of Fe to C 2:1,residence time of wastewater 1.5 h in Fe/C micro-electrolysis simultaneously,dropping speed of H2O2(30 wt.%)0.025 mL/min during electro-Fenton,air stripping time 1.5 h at pH 10 with 1.5 L/min of air flow.Results showed that effluent was nearly transparent,and removal rates of suspended solid(SS),NH3-N,COD,BOD5 were 94.2%,71.4%,51.8% and 28.3% respectively,which would create favorable conditions for subsequent biochemical treatment in depth.Moreover,the ratio of BOD5 to COD increased from 0.12 to 0.19 which implied that biodegradability of effluent was improved obviously.The operation also displayed that electro-Fenton technique brought about better treatment effect than general Fenton process,and the reason for this might be attributed to not only in situ homogeneous and heterogeneous Fenton reactions but also Fenton reaction assisted by electric field were involved under electro-Fenton conditions.