曝气吹脱除嗅的影响因素及模型建立

The Influence Factors of Aerated Stripping Removal of Odor-producing Pollutants and Its Model Building

针对饮用水原水嗅味问题,系统开展了曝气吹脱法除嗅问题的研究。实验中通过吹扫捕集-气质联用(P&T-GC/MS)方法测得任意时刻水体中的残余致嗅物质浓度。为确定影响曝气吹脱的最主要外因,通过对气源、曝气量、原水水质、温度几个主要影响曝气去除效果的因素分析发现,气源、原水水质对去除率无影响;不同曝气量相同气水比条件下小气量长时间曝气的去除率略高于大气量短时间的曝气;不同的环境温度对土臭素(GSM)和二甲基异莰醇(2-MIB)的曝气吹脱去除效果影响很大。相较于5℃,25℃条件下40 min内GSM和2-MIB的去除效果分别提升了1.7倍和2.5倍。曝气吹脱过程可用一级反应动力学表示,通过与现有实验数据的拟合,以及阿伦尼乌斯公式对模型内曝气吹脱系数的温度修正,得到具有现实指导价值的曝气吹脱模型。最终,模型预测值与实测值间的误差可控制在10%范围内。

Aiming at the odor problems occurred in a source drinking water; systematic experiments were conducted on removing geosmin（GSM） and 2-methylisoborneol（2-MIB） by aerated stripping. To determine the most important external factors of the aerated stripping, through the analysis of several main factors affecting the effects of aeration including air,amount of aeration, raw water quality, temperature, it was found that, under the different aerations with the same gas-water ratio, different environment temperatures for geosmin（GSM） and 2-methylisoborneol（2-MIB） have a great influence to the result of the aerated stripping. Compared to 5 ℃, under the condition of 25 ℃ the removal effect of GSM and 2-MIB were raised by 1.7 times and 2.5 times respectively in 40 min. Aeration stripping process can be represented by the first-order reaction kinetics, through fitting the existing experimental data, and the temperature correction of the aeration stripping coefficient in the model by the Arrhenius equation, the aerated stripping model with the practical guidance value can be obtained.