Typology of Municipal Wastewater Treatment Technologies in Latin America

Abstract

This paper presents an analysis of the wastewater treatment plants in six Latin American and Caribbean countries. Based on a sample of 2734 municipal treatment facilities, the applied processes are classified by sizes (influent flow) and type of technologies. The distribution of the technologies is also presented for each of the six countries. In addition, a representative municipal wastewater characterization, based on influent data from 174 treatment plants, is proposed. Results show that stabilization ponds, activated sludge, and the upflow anaerobic sludge blanket reactors represent 80% of the treatment facilities of the sample, providing treatment to 81% of the total flow considered. Moreover, 67% of the plants in the sample are small (flow <25 L/s) and the very small facilities (influent flow <5 L/s) are extensively applied in the region (34% of the sample), especially in Mexico and Brazil. The use of very small treatment plants may result in low energy efficiency systems and on possible incompliance of the discharge standards. This common practice in several countries in Latin America should be revised in order to improve the environmental performance of such facilities.Abbreviations: BOD, biochemical oxygen demand; GHG, greenhouse gas; UASB, upflow anaerobic sludge blanket 926Clean -Soil, Air, Water 2012, 40 (9), 926-932

Methane emissions from stabilization ponds for municipal wastewater treatment in Mexico

“…In such case, the mitigation possibilities are clear and focus on increasing the treatment capacity of the country, meeting at the same time the existing environmental regulations. This should be done based on sound decisions on selecting treatment technologies that may have lower environmental impact, meeting technical and economic criteria (Noyola et al 2012). …”

“…Based on the number of facilities, stabilization ponds (SP) are the most applied WWT process in the region (Noyola et al 2012). SP comprise an arrangement in series, basically anaerobic, facultative and maturation ponds, or just two of these elements.…”

UN World Water Development Report 2017: "Wastewater: The untapped resource"

“…The principal technologies used (approximately 80% both in terms of the number of facilities and of treated flow) are stabilization ponds, activated sludge and up-flow anaerobic sludge blanket reactors (Noyola et al, 2012). …”

“…Moreover, many wastewater treatments plants, particularly in smaller communities, are plagued by poor operation and maintenance, and are sometimes eventually abandoned because of a lack of technical and financial capacity among local governments and service providers. Most of these facilities are small and cannot take advantage of economies of scale, resulting in high costs and high probability of incompliance with discharge standards (Noyola et al, 2012). Urban wastewater is still largely regarded as waste and as leading to additional costs, rather than a potential source of water supply and nutrients which can substantially reduce the pressures on the environment.…”

Método de diseño reducido para lagunas de estabilización

“…Según Noyola et al (2012), la tecnología más utilizada para el tratamiento de las aguas residuales en México es de lagunas de estabilización, con 40% de las plantas. Además que la mayoría de las instalaciones de tratamiento de aguas residuales (60%) operan con flujos iguales o menores a 5 L/s y se clasifican como plantas pequeñas.…”