Paul Taboada-González

Household Solid Waste Characteristics and Management in Rural Communities

Globally there is a lack of knowledge about waste generation and composition in rural areas because these types of studies have been conducted mainly in big cities. This leaves the local sanitation authorities without information to properly plan its operations. Generally, characterization studies are carried out by using the technique of sampling taking at home level. This method requires human, material and economic resources that sometimes are limited for local sanitation authorities. This paper presents the results of a characterization study obtained by direct analysis of household solid waste generated in two rural communities in northern Mexico. The research also outlines a procedure for estimating the waste generation rate when financial constraints prevent the development of a characterization study at home level. This study attempts to fill the information gap on the generation and composition of solid waste in rural areas. The results indicate a waste generation of 0.631 kg/cap/day in San Quintin and 1.047 kg/cap/day in Vicente Guerrero. The specific weights of the uncompacted SW were respectively 145 kg/m 3 and 123 kg/m 3 . The specific weight of the compacted SW was 229 kg/m 3 in San Quintin. Statistically, the composition of waste between these two rural communities differs in one fraction.

Municipal Solid Waste Generation and Characterization in Ensenada,Mexico

A comprehensive study of the generation and characterization of municipal solid waste is essential to the long- term efficient and economical planning for solid waste management. The aim of this study was to quantify and analyze the solid waste generated in the city of Ensenada, Mexico, and to use this data in a project that will generate energy through methane gas production. Ensenadas per capita waste generation is approximately 0.87 ± 0.07 kg per person per day within a 98% confidence interval. Ensenadas solid waste composition consists of food scraps at 34.28%, paper and cardboard 22.49%, plastic 12.53%, disposable diapers 7.14%, and textiles 6.58%. Of the total waste generated, 86.36% has potential for reuse, whereas 13.65% has no further identifiable use and must be landfilled. Of the usable percentage, 48.34% can be recycled and 51.66% can be used to generate energy, obtaining financial and environmental benefits.

Application of analytic hierarchy process in a waste treatment technology assessment in Mexico

The high per capita generation of solid waste and the environmental problems in major rural communities of Ensenada, Baja California, have prompted authorities to seek alternatives for waste treatment. In the absence of a selection methodology, three technologies of waste treatment with energy recovery (an anaerobic digester, a downdraft gasifier, and a plasma gasifier) were evaluated, taking the broader social, political, economic, and environmental issues into considerations. Using the scientific literature as a baseline, interviews with experts, decision makers and the community, and waste stream studies were used to construct a hierarchy that was evaluated by the analytic hierarchy process. In terms of the criteria, judgments, and assumptions made in the model, the anaerobic digester was found to have the highest rating and should consequently be selected as the waste treatment technology for this area. The study results showed low sensitivity, so alternative scenarios were not considered. The methodology developed in this study may be useful for other governments who wish to assess technologies to select waste treatment.

Household hazardous wastes as a potential source of pollution: a generation study.

Certain domestic wastes exhibit characteristics that render them dangerous, such as explosiveness, flammability, spontaneous combustion, reactivity, toxicity and corrosiveness. The lack of information about their generation and composition hinders the creation of special programs for their collection and treatment, making these wastes a potential threat to human health and the environment. We attempted to quantify the levels of hazardous household waste (HHW) generated in Mexicali, Mexico. The analysis considered three socioeconomic strata and eight categories. The sampling was undertaken on a house-by-house basis, and hypothesis testing was based on differences between two proportions for each of the eight categories. In this study, HHW comprised 3.49% of the total generated waste, which exceeded that reported in previous studies in Mexico. The greatest quantity of HHW was generated by the middle stratum; in the upper stratum, most packages were discarded with their contents remaining. Cleaning products represent 45.86% of the HHW generated. Statistical differences were not observed for only two categories among the three social strata. The scarcity of studies on HHW generation limits direct comparisons. Any decrease in waste generation within the middle social stratum will have a large effect on the total amount of waste generated, and decrease their impact on environmental and human health.

Solid Waste Management in a Mexican University Using a Community-Based Social Marketing Approach

Waste separation and recycling programs in higher education institutions requires an approach that reach people in different ways. Social marketing approach has proved to be effective in helping reach the desired change for very different initiatives. In this paper is presented a sixteen month experience of a paper and cardboard separation program at the Ensenada Campus of the Autonomous University of Baja California (UABC). Although the support from the University authorities is important, through different experiences it was found that in UABC the programs that work better are the ones that do not depend on the work of personnel but on the participation of students and academic staff. To gain this participation the strategies used in social marketing were used. To date through UABC s paper and cardboard program the institution has diverted more than six tons of this type of waste from the main waste stream. Based on the evaluation of the program and on the increasing community response, it can be said that the social marketing strategies used in this program were successful.

Adaptación de Inóculos Durante el Arranque de la Digestión Anaerobia con Residuos Sólidos Orgánicos

espanolEn este estudio se analizo la adaptacion de dos inoculos, tomados en una industria lactea y una industria cervecera, en digestores anaerobicos de mezcla completa (CSTR). El estudio es necesario porque en el uso de la tecnologia anaerobica, el arranque del sistema es critico y lento, y para acelerar el tiempo de arranque de un digestor anaerobico, se recurre a la inoculacion. Se caracterizaron los residuos de alimentos y los inoculos, se alimentaron los digestores a una misma concentracion y composicion del residuo organico, y se analizo la reaccion de degradacion durante 150 dias. La adaptacion del inoculo dos (industria cervecera) al residuo organico fue mas rapida y estable en el proceso de degradacion, lo que dio un mayor rendimiento de biogas y concentracion de metano (48.3%). Sistemas de digestion operando con un pH por debajo de 6.5 producen biogas con bajo contenido de metano. EnglishIn this study, the adaptation of two inoculums, taken from a dairy industry and a brewing industry, in continuous anaerobic flow stirred digesters (CSTR) was analyzed. The study is needed because in the use of anaerobic technology, the start-up of the system is critical and slow and inoculation is used to speed up the start-up time in anaerobic digesters. The food waste and inoculums were characterized, the digesters were fed at the same concentration and composition of organic waste, and degradation reaction was analyzed during 150 days. The adaptation inoculum two (brewing industry) to the organic residue was faster and more stable in the degradation process, resulting in a higher yield of biogas and methane concentration (48.3%). Digestion systems operating with a pH below 6.5 produce biogas with low methane content.

GENERACIÓN Y COMPOSICIÓN DE LOS RESIDUOS SÓLIDOS URBANOS EN AMÉRICA LATINA Y EL CARIBE

En America Latina y el Caribe (ALC) las viviendas continuan siendo la fuente principal de generacion de los residuos solidos urbanos (RSU), por lo que la informacion veraz sobre la generacion y composicion es fundamental para su gestion, ya que en general carecen de infraestructura suficiente para el tratamiento adecuado de estos. Esta investigacion analiza la generacion de residuos solidos domesticos (RSD), a efecto de comparar su composicion y establecer similitudes y diferencias que inciden en los patrones de generacion de RSU en esta region. El analisis y comparacion de la composicion se realizo con base en datos de generacion de RSD (kg/hab-d) de las ciudades de Asuncion, Paraguay; Ensenada, San Quintin, Vicente Guerrero, Morelia y Zinacantepec, Mexico; Mataucana y Trujillo, Peru; Cartagena, Colombia y Quito, Ecuador. Entre los principales resultados se encontraron variaciones en la generacion y composicion de los RSD de las ciudades estudiadas y la fraccion organica continua siendo predominante; no obstante la heterogeneidad de la composicion se ha incrementado, siendo la mayor parte de componentes reciclables. Los analisis de generacion en los paises de estudio confirman que las viviendas de ALC mantienen una estratificacion socioeconomica similar pero que no incide en la composicion y cantidad de residuos solidos producidos. Lo anterior corrobora la importancia de contar con datos precisos y actualizados de tasas de generacion y composicion, ya que estos datos son criticos para el diseno de programas de gestion que incluyan el reciclaje y la disposicion final adecuada.

Optimización de un Sistema de Abastecimiento de Pintura a Concesionarios de Baja y Media Demanda

espanolEl objetivo de este estudio fue optimizar el sistema de administracion de inventarios en un centro de distribucion que ayude a incrementar la productividad de la empresa. Esto es de interes porque uno de los aspectos de exito de una empresa se refiere a la adecuada operacion de los centros de distribucion. Se hizo una clasificacion ABC de los articulos mas representativos de una empresa de distribucion de pinturas y se realizaron proyecciones empleando el software Oracle CrystalBall®. Se realizo un estudio de las instalaciones y equipo de manejo de materiales. Los porcentajes de utilizacion anual son 47.87% para los articulos clase A, 38.24% para los articulos clase B y 13.89 para los articulos clase C. La capacidad actual de almacenaje es suficiente para la demanda. El trabajo muestra que el desarrollo de politicas de inventario adecuadas permite mantener un resurtido dinamico al centro distribucion. EnglishThe aim of this study was to optimize a system for inventory management in a distribution center to help increasing business productivity. This is of interest because one aspect for the success of a company is related to the proper operation of the distribution centers. An ABC classification of the most representative items of a paint distribution company was carried out, and projections were done using the Oracle software CrystalBall®. A study of the facilities and material handling equipment was performed. The annual utilization rates are 47.87% for the class A items, 38.24% for Class B items and 13.89% to class C items. The current storage capacity is sufficient for the present demand. This work shows that the development of appropriate inventory policies keeps a dynamic refill in the distribution center.