Technical and economic pre-feasibility study for the construction of septic tank-filter-sinkhole with alternative material
1Federal Fluminense University (UFF), Department of Agricultural Engineering and Environment, Street Passo da Pátria, n.156, Boa Viagem, Niterói-RJ, Brazil
²North Fluminense State University (UENF), Civil Engineering Department, Avenida Alberto Lamego 2000 - Parque Califórnia, Campos dos Goytacazes BR28013-602 Rio de Janeiro, Brazil
³SEMAG/Aracruz, Av. Morobá, n.20, BR 29192-733 Bairro Morobá-ES, Brazil
⁴José do Rosário Vellano University (UNIFENAS), Department of Veterinary Medicine, Rodovia MG-179 km 0, s/n -Bairro Trevo, BR 37130-000 Alfenas-MG, Brazil
⁵Évora University (UE), Pólo da Mitra, PT 7002-554, Évora, Portugal
The study of the different materials used in the construction of septic tanks aims to facilitate and spread the use of this sewage treatment system in places that are not assisted by municipal sewage systems and in the rural area, which despite having a smaller number of inhabitants compared to the urban area This study aims to carry out a technical and economic evaluation of the concrete and tires using in the construction of septic tanks-filter-sinkhole. The wastewater treatment systems were built according to the recommendations in NBR 7229/93 and 13969/97. To evaluate the efficiency of each system built, the following parameters were analyzed: chemical oxygen demand (COD), the potential of hydrogen (pH), alkalinity, acidity, and temperature. In the economic evaluation, the materials and labor required to install the systems were considered using the Brazilian cost database (SINAPI), and an economic and financial feasibility study was carried out. According to the technical and economic analysis of construction, both systems showed the same technical performance, however, the concrete design proved to be more advantageous than the tire design, considering the difficulty in acquiring the tires and the high cost if it is necessary to buy them, in addition to the greater difficulty in handling and installing the tire system compared to the concrete one.