Treatment for domestic wastewater by using aerated ponds

Abstract

The study was undertaken using a pilot plant of aerated ponds which consists of two systems called A and B, each one with three-tank system in series in order to evaluate the performance of the plant. The biochemical oxygen demand (BOD5,20) and soluble biochemical oxygen demand (BODsoluble), at the outlet of the A system, were 20 mg/L and 6 mg/L, respectively, very similar to those obtained from the B system where their values were 15 mg/L and 5 mg/L, respectively, this means that they can be achieved the same removal levels for both the A system, with one-day retention time in each pond and for the B system, with two-days retention time in each pond. The removal of chemical oxygen demand (COD) for both A and B systems were very similar, 81 and 85%, respectively. The data obtained from the different species of nitrogen at the effluent from the two systems of aerated ponds demonstrated that were an effective nitrification process. The biological treatment in aerated ponds is adequate to handle this kind of wastewater, since it is possible to get, with a single pond, a removal to 91% of the organic load in terms of BOD with one-day retention time.

Keywords

• wastewater
• biochemical oxygen demand
• aerated ponds
• removal
• biological treatment