兼氧接触水解酸化预处理化工废水的试验研究

Experimental study on facultative bioattached hydrolytic acidification in pretreatment of chemical industrial wastewater

采用兼氧接触水解酸化工艺预处理某化工废水。试验结果表明:当进水CODCr的平均质量浓度为1980mg/L时,在水解酸化反应器停留时间为24h的条件下,系统对废水CODCr的去除率约为22.7%。系统前段对BOD5有少量的去除;在后段BOD5升高,BOD5与CODCr质量比由原水的0.38提升至0.51,废水的可生化性得到了明显的改善。氨氮及VFA的变化规律表明,在水解酸化的前段,在水解酶的作用下大分子杂环化合物断键生成中等分子有机物,同时发生加氨作用;在水解酸化的后段,在酸化作用下脱氨开环,形成小分子的VFA等。

Facultative bioattached hydrolytic acidification was used to pretreat chemical industrial wastewater. The results of the experiment showed that： under the condition that, the average mass concentration of CODcr in influent water was 1 980 mg/L, the hydraulic retention time of the hydrolytic acidification reactor was 24 h, the removal rate of CODcr was about 22.7%. Low BOD5 removal rate was obtained in the forepart of the system; in the backpart of the system, the mass concentration of BOD5 increased and the mass ratio of BOD5 to CODcr increased from 0.38 to 0.51, the biodegradability of the wastewater was greatly improved. The change rules of ammonia nitrogen and VFA indicated that, in the forepart of the hydrolytic acidification, under the effect of hydrolase, middle molecular organic compounds were created through the macromolecular heterocyclic compounds＇ bond breaking, and the adding-amidogen step was also involving in this part; in the backpart of the system, doffing-amidogen and open loop occurred under the acidification effect, and micromolecular VFA was formed.