多点投加推流式反应器深度处理己内酰胺废水研究

Study on advanced treatment of caprolactam wastewater with multipoint-feed push flow reactor

为优化基于O_(3)-H_(2)O_(2)高级氧化技术的多点投加推流式反应器处理己内酰胺废水生化出水的工艺参数,通过改变气液比、H_(2)O_(2)投加量及反应停留时间等工况条件,考察多点投加推流式反应器对有机物去除效果及出水特征变化的影响。随着气液比的增加,COD和UV_(254)去除率不断提高,对应的O_(3)与ΔCOD浓度比上升,O_(3)利用率明显下降。与单独投加O_(3)相比,O_(3)-H_(2)O_(2)模式下COD和UV_(254)去除率明显提高。随着H_(2)O_(2)投加量的增大,O_(3)利用率接近100%。随着反应停留时间的增加,COD和UV_(254)去除率不断提高,对应的O_(3)与ΔCOD浓度比快速上升,O_(3)利用率明显下降。结果表明,当气液比为0.06 Nm^(3)/m^(3),H_(2)O_(2)与O_(3)物质的量比为0.2,反应停留时间为8 min时,COD和UV_(254)去除率分别达到32.5%和23.3%,O_(3)与ΔCOD浓度比为2.2,O_(3)利用率为97.2%,m(BOD5)/m(COD)从0.08上升到0.20。与处理前相比,经深度处理后己内酰胺废水生化出水中相对分子质量小于1 kDa的COD占比降低,疏水中性有机物及疏水酸性有机物的COD占比均显著下降,XAD-4酸和其他亲水性有机物均明显增加。

In order to optimize the process parameters for the treatment of caprolactam wastewater biochemical effluent by multi-point-feed push flow reactor based on O_(3)-H_(2)O_(2) advanced oxidation technology.The effect of multi-point-feed push flow reactor on organic matters removal and effluent water characteristics were investigated by changing gas-liquid ratio,H_(2)O_(2) dosage,reaction retention time,and some other working conditions.With the increase of gas-liquid ratio,the removal rates of COD and UV_(254) were improved continually,and the corresponding concentration ratio of O_(3) to△COD also rised,while the utilization rate of O_(3) decreased obviously.Compared to adding O_(3) alone,the removal rates of COD and UV_(254) in O_(3)-H_(2)O_(2) mode were significantly improved.With the increase of H_(2)O_(2) dosage,the O_(3) utilitzation rate was close to 100%.With the prolong of the reaction retention time,the removal rates of COD and UV_(254) were improved continuously,the corresponding concentration ratio of O_(3) to△COD rised rapidly,the O_(3) utilization rate decreased obviously.The results showed that,when the gas-liquid ratio was 0.06 Nm^(3)/m^(3),the mole ratio of H_(2)O_(2) to O_(3) was 0.2,the reaction retention time was 8 min,the removal rates of COD and UV_(254) reached 32.5%and 23.3%respectively,the concentration ratio of O_(3) to△COD was 2.2,the O_(3) utilization rate was 97.2%,the m(BOD_(5))/m(COD)value was increased from 0.08 to 0.20.Compared to the situation before the treatment,through the advanced treatment,the proportion of COD with molecular weight lower than 1 kDa in the biochemical effluent of caprolactan wastewater decreased,the proportion of COD of hydrophobic neutral organic matters and hydrophobic acid organic matters decreased significantly,and the proportion of XAD-4 acid and other hydrophilic orgnic matters increased obviously.