منابع مشابه
Modeling and Predictive Control of Pellet Reactors for Water Softening
A nonlinear chemical/physical dynamic model in the form of partial differential equations was adopted and further developed to serve as a basis for model predictive control of a pellet reactor for drinking water softening. The model was calibrated using full-scale process measurements. A linear predictive controller based on a lineralization of the model has been designed to achieve the desired...
متن کاملReuse of water treatment residuals from lime softening, Part I: Applications for the reuse of lime sludge from water softening
Lime sludge, an inert material mostly composed of calcium carbonate, is the result of softening hard water before distribution as drinking water. A large city such as Des Moines, Iowa, produces about 32 000 tons of lime sludge (dry-weight basis) annually. This is about half of the lime sludge produced in Iowa per year in eight different cities, and these cities currently have 371 800 tons (dry-...
متن کاملBiomineralization of Calcium and Magnesium Carbonate Minerals Induced by Bacillus licheniformis and Its Application in Water Softening Short title: biomineralization induced by bacteria and application in water softening
Reducing the hardness of hard water is of great concern nowadays due to some adverse effects on water pipes, boilers and soap consumption. Using the method of biomineralization to precipitate calcium and magnesium ions to become carbonate minerals was one of the most important innovations for reducing the hardness of hard water. The present study sought to explore the physical and chemical cond...
متن کاملModeling and Simulation of Water Softening by Nanofiltration Using Artificial Neural Network
An artificial neural network has been used to determine the volume flux and rejections of Ca2+ , Na+ and Cl¯, as a function of transmembrane pressure and concentrations of Ca2+, polyethyleneimine, and polyacrylic acid in water softening by nanofiltration process in presence of polyelectrolytes. The feed-forward multi-layer perceptron artificial neural network including an eight-neuron hidde...
متن کاملHard water softening effect of a baby cleanser
BACKGROUND Hard water is associated with atopic dermatitis (eczema). We wanted to determine if a baby cleanser and its individual components altered free ionized calcium (Ca2+) in a simulated hard water baby bath. For these studies, an in vitro determination of free Ca2+ in a simulated hard water baby bath, and an in vivo exploratory study of free Ca2+ absorption into skin from hard water were ...
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ژورنال
عنوان ژورنال: American Journal of Public Health
سال: 1914
ISSN: 0271-4353
DOI: 10.2105/ajph.4.11.1079