Um Estudo para a Aplicação de Gráficos de Controle Estatístico de Processo em Indicadores de Qualidade da Água Potável

Abstract

The water supply in terms of quantity and quality is a growing concern. Water quality has been compromised since the spring, because of the discharge of effluents, which requires investment in treatment plants to ensure the quality of the water supplied. The water leaving treatment plants to the distribution network must achieve the specification for some parameters set in legislation. But in addition to meeting these limits, to maintain the quality of the water supply it is also important to assess the variability. In this sense, statistical control charts play an important role. The main objective of this paper is to analyze the application of statistical control charts for turbidity and residual chlorine, two indicators of the quality of drinking water. The data, both turbidity and residual chlorine, were autocorrelated, and it was necessary to apply specific techniques to solve this problem. Shewhart control charts for individual measures with extended limits extended and applied to residuals from an ARIMA model, were analyzed in this study. These proposals were adequate to monitor these parameters.

Aplicação do Controle Estatístico de Processo (CEP) para monitoramento de melhorias obtidas com o método CAPDo em uma indústria de bebidas

“…Apesar de apresentar dificuldades na detecção de mudanças no processo, o GVI é fácil de ser confeccionado e manuseado, tanto por especialistas, quanto por operadores que não necessitam de habilidades técnicas para trabalhar com esses gráficos (HENNING et al, 2014).…”

“…Alguns aspectos devem ser considerados na aplicação do GVI, tais como: (i) a interpretação do gráfico deve levar em conta a informação de assimetria na distribuição, caso a mesma ocorra; (ii) a correlação entre os pontos do gráfico de amplitude móvel pode estimular um padrão ou ciclos no gráfico e; (iii) o GVI não permite a avaliação direta da dispersão do processo (HENNING et al, 2014;RIBEIRO;TEN CATEN, 2012). O último aspecto pode ser Centro Universitário SOCIESC -UNISOCIESC Joinville, Santa Catarina, Brasil ISSN 2237-5163 / v. 08, n. 01: p. 01-24, ano 2018DOI: 10.14521/p2237-5163.2018 revertido se o cálculo da amplitude móvel for feito pela diferença de cada par de pontos consecutivos, considerando o tamanho amostral (n) igual a 2.…”

Effect of Calcium Hypochlorite in Drip Irrigation System After Application of Red Potassium Chloride

“…For the evaluation of processes in any area, statistical quality control charts are used to observe the quality characteristics of interest, ensuring their maintenance within established limits and indicating when to take corrective and improvement actions. They also allow the systematic reduction of variability in quality characteristics, in an effort to improve the intrinsic quality, productivity and reliability of production or supply (Henning, Walter, Souza, & Samohyl, 2014).…”

Estimation on the Concentration of Suspended Solids From Turbidity in the Water of Two Sub-Basins in the Doce River Basin

“…Large amounts of suspended solids (SS) can affect procreation of fish and invertebrates due to obstruction on breeding habitat (Naveedullah et al, 2016). In addition, TSS can serve as a shelter for pathogenic microorganisms and may be associated to bacterial contamination (Bakan et al, 2010;Henning et al, 2014).…”