Water quality management in a treatment plant using the Box-Jenkins method

Drinking water systems are critical to society. They protect residents from waterborne illnesses and encourage economic success of businesses by providing consistent water supplies to industries and supporting a healthy work force. This paper shows a study on water quality management in a treatment plant (TP) using the Box-Jenkins method. A comparative analysis was carried out between concentrations of water quality parameters, and Colombian legislation and guidelines established by the World Health Organization. We also studied the rainfall influence in relation to variations in water quality supplied by the TP. A correlation analysis between water quality parameters was carried out to identify management parameters during the TP operation. Results showed the usefulness of the Box-Jenkins method for analyzing the TP operation from a weekly timescale (mediumterm), and not from a daily timescale (short-term). This was probably due to significant daily variations in the management parameters of water quality in the TP. The application of a weekly moving average transformation to the daily time series of water quality parameter concentrations significantly decreased the mean absolute percentage error in the forecasts of Box-Jenkins models developed. Box-Jenkins analysis suggested an influence of the water quality parameter concentrations observed in the TP during previous weeks (between 2-3 weeks). This study was probably constituted as a medium-term planning tool in relation to atypical events or contingencies observed during the TP operation. Finally, the findings in this study will be useful for companies or designers of drinking water treatment systems to take operational decisions within the public health framework

Evaluation of hot-mix asphalt containing Portland cement treated blast furnace slag

Iron production’s waste materials include significant quantities of blast furnace slag (BFS) which could potentially be used as a substitute for natural aggregates in hot mix asphalt (HMA) used in highway projects. Although many of properties of slag are interesting, its porosity and absorption rate would lead to greater consumption of asphalt. For this study, a Portland cement (PC) paste was used to reduce the porosity of a BFS. This PC treated BFS (called BFS-C) was then used in an HMA to replace the coarse fraction of a natural aggregate. Marshall, Indirect Tensile Strength (ITS), resilient modulus and Cantabro tests were then carried out on different HMA mixtures that included BFS-C. Using BFS-C, HMA’s resistance under monotonic loading, stiffness under cyclic loading, and resistance to moisture damage increased remarkably. In addition, the Cantabro abrasion resistance of BFS-C improved was better than that of the HMA mixture produced with untreated BFS

Multi-Criteria Approach for Prioritizing and Managing Public Investment in Urban Spaces. A Case Study in the Triple Frontier

The aspirations of public administrations to meet quality parameters and standards in urban spaces have fostered new strategies and tools that allow users to give safety and well-being. The participation and interaction of different actors during decision-making in the context of allocation of public resources implies a significant degree of complexity when prioritizing actions in public works. The objective of the study focuses on obtaining an urban street condition index (USCI) that allows an efficient diagnosis of urban infrastructure. The study provides an innovation component for decision-making through the construction of guidelines to prioritize spending on investment in urban infrastructure. The case study has been developed in three countries, Brazil, Paraguay and Argentina (Triple Border) with the aim of drawing management guidelines during the process in public entities. The results for Brazil and Argentina present streets with satisfactory USCI. Paraguay reflects a significant lack of urban infrastructure and compliance of accessibility regulations. Regarding the city of Foz de Iguazú, it has been observed that 50% of the roads require prevailing actions to improve the mobility of the roads; 40% of these reflect reduced mobility and deterioration of urban components, configured as an urgent action, and only 10% of the roads studied reflect adequate mobility conditions

Preliminary study of hot mix asphalt containing water treatment and sewage sludge

Throughout the world, considerable quantities of water treatment sludge (WTS) and sewage sludge (SS) are produced as waste. This study assessed in the laboratory, the possibility to use both waste products when they are incorporated as filler at 1% with relation to the total mass of a hot mix asphalt - HMA. To this end, both waste products were initially reduced to ash through a calcination process. Resistance tests under monotonic load (Marshall and indirect tension tests), and cyclic load (resilient modulus test) were applied on mixes that contained WTS and SS. Besides, moisture damage (modified Lotmman test), and abrasion (Cantabro) resistance were assessed. An analysis of variance (ANOVA) test was performed in order to verify if the results are statically equal or not to those of the control HMA. As a general conclusion, it is reported that both materials show a resistance increase under monotonic load and higher stiffness under cyclic load (cohesion) when they are incorporated into the mix as filler despite the fact that the asphalt content used was less than the control mix. However, some problems are observed associated with moisture damage resistance, and friction wear (adherence)

The mechanical behavior of two warm-mix asphalts

This paper presents results stemming from a comparative experimental analysis of two warm-mix asphalts (WMA) and a dense-graded hot-mix asphalt (HMA). In order to evaluate asphalt mixture behavior, physical and rheological tests were conducted, including tests on resilient modulus, resistance to moisture-induced damage, resistance to fatigue and resistance to permanent deformation. Samples studied were subjected to short (STOA) and long-term (LTOA) aging. As far as asphalt mixture composition is concerned, the same particle size distribution and coarse aggregate were employed for both mixture types. The control HMA mixture was produced with AC 60-70, and the WMAs used the same asphalt cement modified with two chemical additives (Rediset WMX® and Cecabase RT®). The modified mixtures exhibited better resistance to permanent deformation, aging and moisture-induced damage (versus the control mixture). Likewise, WMAs generally saw increased fatigue resistance under controlled-stress loading, which rheological characterization showed is mainly attributable to binder additives and their concomitant modifications

Adquisición y análisis de señales electromagnéticas y meteorológicas

IP 1101-06-010-93Torres -- Lightning peak current estimation analysis fromfieldmeasurements in tropical zones / H. Torres --;The lightning parameters and its spatial (Latitudinal-Topographical) and temporal dependence / H. Torres..;(et al.) -- Nueva metodologia para la evaluacion del factor deriesgo parala proteccion de estructuras;contra rayos;ARTICULOS DE REVISTA : Fenomenologia del rayo / H. TorresEn :Revista Innovacion y Ciencia. Vol. 3, no. 3;(1994) -- Modelos de transformadores de distribucion / H.Torres, L. Barreto En : Revista Mundo Electrico;Colombiano. (Oct. - Dic. 1996) -- Las perturbaciones electromagneticas / L. Buarreto, H. Torres. En : Revista;Innovacion y Ciencia. Vol. 5, no. 2 (1996);PONENCIAS : Multiple time series analysis in tropical lightningresearch /H. Torres, T. L. Barreto, L. A.;Enciso -- Lightning research in Colombia / H. Torres, F. Herrera'-- Estimate of ground flash density and;lightning peak current with one station direction finder /H.Torres, L. Barreto -- Armonicos y calidad de;servicio / L. Barreto, H. Torres -- Procesamiento de señales para analisisde armonicos / L. Barreto, H.;Torres -- Analisis de armonicos : estudio de casos / H. Torres..(et al.) -'- Simulacion de armonicos no;caracteristicos / E. Cano, H. Torres -- Modelos de transformadores de distribucion / H. Torres.(et al.) --;Methodology for lightning protection at petroleum explorationsites / H. Torres..(et al.) -- Caracterizacion;de armonicos : estudio de caso / H. Torres..(et al.) -- Lightning protection for petroleum facilities / H