Dear Wei, As I am sue you ...

Dear Wei,

As I am sue you agree with me, not all the technologies can be used to solve all the problems. Even more there is not a unique solution to solve this problem.

Before select which one is the best option in your case we must understaand all the problem.

If you have a small area (or need a portable system), and need a simple and efficient operation, an AOP can be used.

I suggest you considere the ozone becuse it can do the work in a simple way starting inmediatly, and even if you need it could digest to non detectable level (to transform in CO2 the COD if required), better than whatever biological system and with a better footprint performance (COD/m2).

If you have a bigger and enought area, and time to start it,  you could invest in a complete or a more complex biological system to remove the COD. In some of this second option you will need special skilled people or remote control or in the worse case both, to operate the system.

If you have a little more area, you can even construct a lagoon to treat it there.

Of course the cost and election of each system will depend on the flow, COD and other parameters including Total Ownership Cost.

In general terms:

The biological systems have higher purchase cost and lower operation cost.
The AOP systems have lower purchase cost and highest operation cost.

Depending on the Total Ownership Cost and (ROI) evaluation you could select a combination of both.

Regards,

Orlando D. Gutiérrez Coronado