臭氧预氧化对城市污水二级出水可生化性的影响

以臭氧预氧化强化后续曝气生物滤池对城市污水二级出水中难降解有机物净化效率为目的,研究了臭氧预氧化对二级出水可生化性的影响。臭氧投量为10mg/L、接触时间为4min时,臭氧氧化对COD和TOC去除率分别达到25.7%和16.5%;臭氧氧化使二级出水的生物可降解有机碳(BDOC)值提高为原来的2.45倍;臭氧氧化使二级出水中有机物的分子量分布发生了明显的变化:大分子有机物比例减少,小分子有机物比例增加,使分子量小于1kDalton的有机物的比例由原来的52.9%提高到72.6%;通过UV254值变化可知,臭氧氧化能将大多数含有C=C、C=O双键等活性基团破坏;臭氧氧化后,GC/MS检测到的有机物种类和数量明显增多,氧化前后烷烃种类明显增多,而环状结构、羧酸和醇类化合物明显减少。

Effect of Pre-ozonation on Biodegradability of Secondary Effluents of a WWTP

With the purpose to upgrade a WWPT by use of the biological aerated filter (BAF) process, a bench-scale experiment on preozonation’s effect on biodegradability of its secondary effluents is conducted. The experimental study showed that with an ozone dosage of 10mg/L and a duration of 4min contact would enhanced removals of COD and TOC by 25. 7% and 16.5% respectively;and increased value of biological dissolved organic carbon ( BDOC) by 1.45 times. The preozonation destroyed most of the active structures such as C=C and C=O, resulting in an increase of the percentage of smallmolecular-weight organics( <1k Dalton). Furthermore, the CG/MS detection indicated that pre-ozonation promoted the increase of some organics, i.e, alkyl compounds, while cut down the compounds with groups such as phenyl, carboxyl and alcohol.