**1.3 Methodology**

The pilot plant was just built to study the performance of air injection nonporous diffuser (aeration system) in an activated sludge tank with a continuous overflow system of wastewater out of a flocculation system with the aim to simulate a biological tank.

The apparatus is just built as in **Figure 5** from the following items:


*Study of Change Surface Aerator to Submerged Nonporous Aerator in Biological Pond… DOI: http://dx.doi.org/10.5772/intechopen.104860*

*Test apparatus arrangement: (a) sludge tank. (b) oxygen indicator device, (c) air diffuser.*

### **The procedure of the experiment:**


**Figure 6.** *Apparatus diagram.*

