TECHNICAL ASSISTANCE, CONTROL AND MONITORING OF THE REHABILITATION AND EXTENSION WORKS OF THE JENDOUBA WASTEWATER PLANT

Project components

The rehabilitation and extension of the Jendouba wastewater treatment plant is sized to meet the treatment needs of the project area until the year 2041, the project will increase the capacity of the plant to 9,400 m3/d for a load of 4,050 kg/d of DBO₅. The process is biological treatment by low-load activated sludge, in an oxidation basin followed by sand filtration and UV disinfection, and dehydration of the sludge by two centrifuges while leaving the existing drying beds in service. Nitrogen removal is ensured by nitrification and denitrification. Phosphorus treatment by chemical precipitation is also planned. Odor treatment is planned in the WWTP by biofiltration.

The treatment line includes the following structures:

• 3 Archimedes screws lifting wastewater by;
• screening consisting of a mechanical screen;
• grit and oil removal in a double aerated channel;
• flow measurement in a Venturi channel;
• oxidation of organic matter in 2 treatment lines, each with 2 reactors each comprising 3 basins in series (total 12 basins) equipped with surface aerators and submersible agitators;
• sedimentation of sludge in 2 secondary decanters (4 basins) of rectangular plan, equipped with suction scraping bridge;
• sand filtration and UV disinfection;
• recirculation of sludge to the start of the aeration basins;
• extraction of excess activated sludge to the thickener;
• dosage with aluminum sulfate for chemical precipitation of phosphorus;
• thickening of excess sludge in 1 thickener of square plan, equipped with scraping bridge;
• dewatering of thickened sludge on 26 drying beds.

Scope of works

The services cover three main missions:

• Mission A: Technical assistance for the evaluation of offers
• Mission B: Control of studies and approval of execution plans
• Mission C: Control, monitoring and supervision of works and performance control