General

Exchange equilibria have been determined for pure cation and anion exchangers as well as for amphoteric materials such as activated alumina and activated carbon. The pretreatment of these materials and the experimental conditions needed for obtaining proper equilibrium data have been described in detail in several publications. Cation concentrations can be measured by titration, photometric methods or by atomic absorption spectroscopy. Nitrate concentrations are measured photometrically, chloride and sulfate concentrations by ion chromatography.

In the case of pure anion or pure cation exchange, equilibria samples with increasing amounts of exchanger material are contacted with a fixed volume of the solution at constant temperature until equilibrium is obtained. Experiments with amphoteric equilibria are carried out at constant concentrations in the liquid phase and constant quantities of activated alumina or activated carbon in each of the samples. The volume/mass ratio is adjusted so that there is a substantial degree of sorption, as well as an equilibrium concentration that can be measured easily and with sufficient accuracy. Since the state of equilibrium is mainly dominated by the pH of the liquid phase, the pH value is varied in each series of samples. Details are described in the literature.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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