Spreading sewage sludge from municipal wastewater (MWW) treatment on land is still a common practice in developing countries. However, it is well known that sewage sludge without special treatment contains various pollutants, which are (re)introduced into the environment by sludge landspreading and which might in turn have harmful effects on the environment and human health. This is more dangerous in places like Merida, Mexico, where soil is calcareous with fractures along the ground and thin layers of humus. Consequently, any liquid and semisolid wastes have the potential of percolating to the subsurface and contaminate the aquifer. The main aim of this work was using composting as a low cost process to eliminate pathogens contained in sewage sludge from MWW treatment in order to use the final product for land spreading in a safe way for both environment and human health. Two piles for composting process at real scale were settled using a mixture of sewage sludge from municipal waste water and green waste. Composting was carried out by windrow process and it was monitored during four weeks. Concentration of helminth eggs, salmonella and faecal coliforms were measured twice a week to observe its behavior and, as a control process, Temperature, Moisture Content (MC), and pH were also measured. After 30 days of composting sludge from municipal waste water system, salmonella was eliminated by 99%, faecal coliforms by 96% and helminth eggs by 81%. After 3 months compost reached GI = 160%, so did not show any phytotoxicity to seeds.
Maga？a, A. Reactor Anaerobio Horizontal Doble (RAH-D) su desarrollo en la FI-UADY(in Spanish). Ingeniería, Revista Académica de la Facultad de Ingeniería de la Universidad Autónoma de Yucatán. 2002, 6, 61–65.
Febles-Patrón, J.L.; Hoogesteijn, A. Evaluación preliminar de la eficiencia en las lagunas de oxidación de la ciudad de Mérida, Yucatán(in Spanish). Ingeniería, Revista Académica de la Facultad de Ingeniería de la Universidad Autónoma de Yucatán 2010, 14, 127–137.
Manios, V.I.; Stentiford, E.I.; Kefaki, M.D.; Siminis, C.I.; Dialynas, G.; Manios, T. Development of a Methodology for the Composting of Sludge in Crete; Grece. In Proceedings of the International Conference of Organic Recovery and Biological Treatment into the Next Millennium, Harrogate, UK, 3–5 September 1997.
Velazquez Aradillas, J.C.; Sauri Riancho, M.R.; Castillo Borges, E.R.; Herrera, J.; Alcocer-Vidal, V.; Estrella–May, F.; Caba？as–Vargas, D.D. Composting Of Septic Sludge. In Proceedings of the International Conference ORBIT 2006, Biological Waste Management: From Local to Global, Waimar, Germany, 13–15 September 2006.
Norma Oficial Mexicana NOM-004-SEMARNAT-2002, Protección ambiental. Lodos y biosolidos. Especificaciones y Límites máximos permisibles de contaminantes para su aprovechamiento y disposición final(in Spanish). Available online: http://www.semarnat.gob.mx/leyesynormas/Pages/inicio.aspx (accessed on 8 July 2013).
Moodley, P.; Colleen, A.; Hawksworth, D. Standards Methods for the Recovery and Enumeration of Helminth ova in Wastewater, Sludge, Compost and Urine–Diversion Waste in South Africa. University of KwaZulu-Natal, Pollution Research Group Report No. TT322/08; WRC: Durban, South Africa, 2008.
Barrios, J.A.; Jiménez, B.; González, O.; Salgado, G.; Sanabria, L.; Iturbe, R. Destrucción de coliformes fecales y huevos de helmintos en lodos fisicoquímicos por vía ácida(in Spanish). In Proceedings of the XII National Conference 2000: “Ciencia y Conciencia, Compromiso Nacional con el Medio Ambiente”, Federación Mexicana deIngeniería Sanitaria y Ciencias Ambientales, Morelia, Mexico, 15–17 April 2000.
Caba？as-Vargas, D.D.; Sánchez-Monedero, M.A.; Urpilainen Kamilaki, A.; Stentiford, E.I. Assessing the stability and maturity of compost at large-scale plants. In Ingeniería, Revista Académica de la Facultad de Ingeniería de la Universidad Autónoma de Yucatán; 2005; Volume 9, pp. 25–30.