Because the wastewater treatment system is a closed-loop system, it can be used for a long time within its design life. If replacement is needed, it is because there is a serious malfunction or aging problem that prevents the system from functioning properly. In this case, the old sewer system needs to be removed and a new one installed. So replacement is not required in that case.
In addition, if the sewage treatment system in Guangxi has been used for a long time, or the treatment efficiency has been reduced, then it is also necessary to consider replacement. In this case, the old sewage treatment system needs to be upgraded to improve treatment efficiency and meet environmental requirements.