Determination of Hydrodynamics in Municipal Waste Water by a Lagoon System with Screens

Stabilization lagoons are economic systems that are built for treatment of municipal, industrial and agricultural wastewater; these systems are used in rural communities. Objective of this article is to present the hydrodynamics flow in lagoon system considering 6 screens with 7 channels containing curved forms with slopes suitable to stabilize the flow along each channel, and approach a piston flow. Hydrodynamics of this system with IBER software was analyzed, where was considered the velocity and hydraulic gradient, using Froude number. Also transport of total suspended solids was modelled. Efficiency in the treatment with this design was evaluated, using parameters such as, pH, conductivity, alkalinity, hardness, total solids, dissolved oxygen, redox potential and Chemical Oxygen Demand (COD). Through the results, a homogeneous transport was observed, mainly dissolved oxygen which was concordant with redox potential and COD, also through the curves, short circuits were minimized, avoiding dead zones and making treatment more efficient, finally were possible to comply with regulations of Mexico NOM-001-SEMARNAT-1996 of discharges and the NOM-003-SEMARNAT-1997 for water of agricultural use.