A study on the biodegradability enhancing by pre-ozonation of an actual secondary municipal wastewater effluent

摘要

A study on the effect of pre-ozonation on the biodegradability of secondary effluent was carried out aiming at enhancing the organics removal rate of the sequent biological aerated filter (BAF). It indicates that 25.7％ of COD and 16.5％ of TOC removal were achieved by pre-ozonation at ozone dose of 10 mg/L and contacting time of 4 min. Pre-ozonation increased the biological dissolved organic carbon (BDOC) by 1.45 times and changed molecular weight distribution of organics as the percentage of organics with molecular weight ＜1k Dalton from 52.9％ to 72.6％. Pre-ozonation destroyed most of the active structures such as C=C and C=O in a short time according to UV254 values decreasing. Furthermore, GC/MS detection results show the categories and quantity of the compounds increased much after pre-ozonation: Alkyl compounds increased and some compounds with groups such as phenyl, carboxyl and alcohol decreased obviously.