Use of multi soil layering system as a secondary treatment of ordinary wastewater.

Abstract

This article is based on experimentation with the Multi Soil Layering System (MSL), which constitutes a novel wastewater treatment technology, its characteristics make it ideal to be applied in rural areas as a centralized system. Previous research has shown promising results when treating domestic wastewater, removing large amounts of organic matter, suspended solids, nutrients, among other contaminants. The MSL is a low cost system that can be built with local materials, offering good performance and a simple and inexpensive operation and maintenance. It is used as a secondary treatment, requiring an area several times smaller than other technologies typically recommended for rural populations.

To carry out the study, four MSL pilots were built, which receive the effluent from an Upflow Anaerobic Sludge Blanket (UASB) reactor that has a previous pretreatment. Quality parameters are measured at the entrance and exit of the systems, such as BOD, COD, TSS, among others.

All pilots were able to comply with the limits established in the national law, and removal percentages of at least 75% were achieved for BOD, COD and TSS. However, these parameters are considerably better in some of the four pilots tested in the study.