Browsing by Author "Torres Lozada, Patricia"
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Item Análisis de peligros y puntos críticos de control en plantas convencionales de tratamiento de agua(Interciencia Association, 2018-01-16) Pérez Vidal, Andrea; Delgado Cabrera, Luis German; Escobar Rivera, Juan Carlos; Cruz Vélez, Camilo Hernán; Torres Lozada, PatriciaEl sistema de análisis de peligros y puntos críticos de control (APPCC) es una herramienta de amplio uso en la industria de alimentos y recomendada en el enfoque de los planes de seguridad del agua (PSA). En este estudio se adaptó una propuesta metodológica aplicable a los procesos de tratamiento de agua que integró los principios del sistema APPCC y los PSA. El estudio se realizó en una planta convencional de potabilización (PTA) en la ciudad de Cali, Colombia, y comprendió dos etapas: 1) identificación de peligros y eventos peligrosos, y 2) determinación de puntos críticos de control (PCC) y puntos de atención (POA). En la primera etapa se caracterizó el agua cruda, clarificada, filtrada y tratada mediante diez jornadas de muestreo y caracterización, en un periodo de 18 meses. En la segunda etapa se adaptó un árbol de decisión que fue aplicado en los eventos peligrosos categorizados en nivel de riesgo medio o superior. Se identificaron un total de 40 eventos peligrosos, 26 PCC y 10 POA, encontrándose como principales PCC las fases de coagulación, floculación/clarificación, filtración y desinfección. La determinación de los PCC contribuyó a la priorización de las fases del tratamiento que requieren de la ejecución de planes de mejoramiento o soporte definidos en los PSA, resultando prioritarios la captación, canales y tuberías de conducción.Item Development and implementation of a water-safety plan for drinking-water supply system of Cali, Colombia(Elsevier GmbH, 2019-11-25) Pérez Vidal, Andrea; Escobar Rivera, Juan Carlos; Torres Lozada, PatriciaThe water-safety plan (WSP) approach integrates risk assessment and management practices into a drinking-water supply system (DWSS), ensuring water quality from the catchment to the consumer. This research was oriented toward the development and implementation of a WSP in the DWSS for the city of Santiago de Cali, Colombia. We adapted the methodological stages of the WSP established by the World Health Organization: (i.) assemble a WSP team, (ii.) describe the existing DWSS, (iii.) identify hazards and hazardous events, (iv.) evaluate risks, and (v.) plan risk management. In this methodological structure, we propose the use of different risk assessment tools at each step of DWSS, which can be implemented in water systems of different sizes. The results of our study allowed the identification of hazardous events that may compromise the effectiveness of the WSP: Of the 103 events found, 16 were related to the catchment, 40 to treatment processes, 27 to the distribution system, and 9 to consumers, while the remaining 11 were associated with organizational, planning, contingency, and emergency factors. We found that the most critical components of the DWSS are the distribution system and the consumers, with 29.6% and 33.3% of the hazardous events classified as at a very high risk level, respectively. Clearly, improvement and support programs for the WSP were needed to optimize existing control measures and corrective actions and to evaluate new ones to reduce risk levels. The treatment processes and distribution system steps were shown as the main barriers of the DWSS mainly they are under governance of water company, unlike the catchment and consumers which presented higher levels of risk because in these steps the water company has less control and influence. Our research confirms that the WSP is an important tool for decision-making by water-service companies—improving their administrative, financial, organizational, and operational management. It also shows that it is essential that their senior management and other stakeholders be part of the WSP team at each stage of implementation of the DWSS.Item Hazard identification in watersheds based on water safety plan approach: Case study of Cali-Colombia(Gheorghe Asachi Technical University of Iasi, Romania, 2016-04) Pérez Vidal, Andrea; Torres Lozada, Patricia; Escobar Rivera, JuanWithin the framework of the Water Safety Plan (WSP), it is necessary to assess and to manage risks in the catchment area, considered the first protection barrier of water supply systems. The Cauca River is one of the major water resources of Colombia and the principal source of drinking water supply for the city of Cali (approx. 2,300,000 people). Taking into account, usually in developing countries, available information and specialized technical resources are limited, in this study were evaluated three management tools of simple application for hazard identification, as a support of risk assessment in the watersheds and integrated with the WSP methodology. The used tools were: (i) matrix of hazardous events, (ii) calculation of Water Quality (WQI) and Water Pollution (WPI) Indexes, and (iii) hazard maps using Geographic Information Systems (GIS). The results showed that the progressive deterioration of water quality is associated with different types of land use of the watershed, which causes diffuse pollution and point source pollution, resulting in the exposure of served population to health risks if adequate treatment barriers are not implemented before the distribution to consumers. The three evaluated tools, showed their usefulness as inputs to risk management and support in activities of surveillance and water quality control. It is important to highlight that the strengthening of the cooperation and active participation of inter-agencies and stakeholders are crucial strategies for risk management in the watersheds.Item Influence of the application of biosolids on the content of humic and fulvic acids in soil cultivated with sugar cane(Fundacion CIPAV, 2016-05-01) Silva Leal, Jorge Antonio; Madriñan Molina, R.; Torres Lozada, PatriciaThis study evaluated the effect of the application of biosolids from a municipal wastewater treatment plant on the content of humic and fulvic acids in vertic Endoaquept soil cultivated with sugar cane. Eight treatments with a randomized block spatial distribution are evaluated using experimental units of 6 m wide x 20 m long: i) control; ii) mineral fertilizer; iii) dehydrated biosolid 1N and 2N; iv) thermally dried biosolid 1N and 2N; and v) alkalized biosolid 1N and 2N (1N and 2N correspond to doses equivalent to one and two times the nitrogen requirement for sugar cane). The results show that while values of humic and fulvic acids showed no significant differences between the control, mineral fertilizer and alkalized biosolid treatments, the application of dehydrated and thermally dried biosolid treatments increased humic acid and fulvic acid content in the soil. This finding demonstrates the benefits of applying such biosolids.