ATOTONILCO – Biggest TUBEdek® installation worldwide in a primary settling tank

Background

The WWTP Atotonilco is Mexico’s largest wastewater treatment plant and the only one of its kind in the world constructed in a single phase. It treats the wastewater from nearly 12.6 million inhabitants of the metropolitan zone of the Mexico City Valley (ZMVM). ENEXIO participated in the project by providing the highly efficient lamella system for the primary treatment with a size of >10,000 m2.

Technical characteristics of the Plant:

TPC =Tren de Procesos convencional/conventional treatment
TPQ=Tren de Procesos químico/chemical treatment

The Task

The task at hand was to reduce the concentrations of incoming TSS of 250 mg/l [dry season]/400 mg/l [rainy season] to normative acceptable concentrations between 40-75 mg/l respectively. These loads of sediments, waste, coarse and heavy solids, fats and more are contained in a monumental peak inflow of up to 42 m³/s being pre-treated in dedicated process treatment trains TPC/TPQ of the WWTP primary treatment.

The Expertise

ENEXIO Water Technologies engineered and installed a highly efficient solution package for the primary treatment sedimentation of the plant under very tight cost-effective and process-wise exigent conditions. The heavy loads of the inflow constituted a high risk of plugging which we can reduce by using our TUBEdek® lamellas.

Our advanced solution in primary treatment consisted of 23 tanks (18 TPC + 5 TPQ) that covers a total area of 10,849 m² and is filled completely with 14,046 m³ lamella packs TUBEdek® in polypropylene. In addition, the integral package included support structure, anti-floating system and launders installed in each of the tanks.

The Advantages

The ENEXIO Water Technologies solution had various advantages:

• Small footprint (10,156 m²) with respect to a monumental effective projected sedimentation area (TPC 73,802 m² + TPQ 13,989 m²)
• Highly efficient sedimentation rate that copes with the risk of plugging in primary treatment
• Integral solution that included a state-of-the-art support structure, accompanied by a hydraulic optimized launders system for optimal water conduction

The Results

With respect to the 10,849 m² that occupy the WWTP trains in TPC/TPQ, the lamellar sedimentation solution of ENEXIO augmented in > 8 times this capacity with an effective projected sedimentation area of 76,942 m². This means 86% more sedimentation capacity.

As a result, after 2 years of the calibration of the TPC/TPQ, reductions of up to 45 mg/l (90%) have been achieved at the effluent.

This contributes immensely to the designed target of collecting about 100,000 ton/a of sand and waste that is generated by the plant and would be sent to the landfill of the plant.