Process for further processing urban domestic sewage

The invention discloses a process for further processing urban domestic sewage, comprising the following steps: leading the urban domestic sewage disposed by routine secondary biochemical system to enter an activated carbon adsorbing tank, automatically switching the system to another activated carbon absorbing tank after saturated adsorption; simultaneously starting an ozone system, backwashing the saturated activated carbon adsorbing tank; leading the wastewater to enter an regulation pool to be processed again by the biochemical system after the BOD/COD ratio of the backwashing wastewater achieves 0.4-0.6; and carrying out the backwashing circularly in all adsorbing tanks. In the invention, the process sufficiently considers the economy and stable running of the ozone generator in the use process of the ozone, solves the problem that the existing mass transfer efficiency is low when the low-concentration wastewater is contacted with the ozone, generates no secondary pollution and reduces the total emission amount of COD in the whole treatment process. The whole system runs conveniently and quickly, and the investment and running expense is far lower than that of the traditional treatment device.