Electrocoagulation (EC) is a wastewater treatment process in which aqueous pollutants can be removed by adsorption, entrapment, precipitation or coalescence during a coagulation step produced by electrochemically generated metallic species. When using Fe as the sacrificial electrode, Fe(2+) and Fe(3+) ions are formed. As Fe(3+) species are paramagnetic, this property can in principle be used to facilitate their removal through the application of a magnetic field. In the present work we present a proof-of-concept for a combined electrochemical-magnetic method for pollutant removal. For this approach, the amounts of Fe(2+) and Fe(3+) produced in an EC cell at various voltages were measured by spectroscopic methods to confirm that Fe(3+) species predominate (up to 84%). The effectiveness of the presence of a magnetic field in the precipitation of coagulants from a suspension was confirmed by monitoring the turbidity change versus time with and without exposure to a magnetic field, up to a 30% improvement.

The existence of solvated electrons has been known for a long time. Key methods for their production (i.e., photoionization of reducing ions, water radiolysis, and the reaction between H· and OH−) are unsuitable for most school laboratories. We describe a simple experiment to produce liquid ammonia and solvated electrons using materials commonly available, without the dangers associated with the use of solid Na or K metal.

A laboratory demonstration is described where preparation of a salad vinaigrette is mimicked when a table salt-looking substance is added to a clear vinegar-smelling liquid. Then, when adding a pepper-looking solid, the whole preparation either sparks or bursts into flames. This phenomenon takes advantage of the well-known gas reaction between ethyne and chlorine.