Construction of a wastewater treatment plant for a Coca-Cola bottler in Ethiopia

In 2020 CUSS designed and realised a wastewater treatment plant for a Coca Cola bottler. The project was finalised successfully in 2022.

CONCEPTUAL FORMULATION:

Bottlers working for Coca-Cola must ensure that the company wastewater effluent standards are met. With mor than 50 projects for Coca-Cola bottling companies we could rely on our experience and were able to quickly design a convincing approach. The main challenge of this project was the altitude of the plant location, approx. 2350 m above sea level. One of the main contributors to the operational costs is the required aeration of the wastewater. Since the air pressure decreases the required energy to provide sufficient aeration increases the higher the altitude of the plant. To minimise the energy requirements and therefor the operational costs of the plant it was decided to use a trickling water to pre-treat the wastewater.

The first step of the treatment is a mechanical pre-treatment to remove abrasive particles, fats, and oil. The wastewater is then neutralised and homogenised. The first step of the biological treatment is a trickling filter with an internal recirculation. During this step about 55% of the biological contamination is removed. This leads to a reduced oxygen demand in the following SBR-treatment. By dosing iron-III-chloride the settling properties of the activated sludge are improved a phosphorus is removed from the wastewater. Remaining particles are then removed by a gravel filtration. Prior to the discharge the clearwater is disinfected.

The during the process produced excess sludge is removed from the system and dewatered using a belt press.