A study of the removal of inorganic mercury by adsorptive bubble separation methods

Abstract

A study of the removal of mercury (I I) from solution by separate adsorptive bubble {adsubble) methods, namely foam fractionation and precipitate flotation, is presented in this thesis. The results indicat the applicability of an adsubble
method as a polishing stage for mercury containing effluents. The aim of the work was to investigate the feasibility of the inorporation of an adsubble method in the clarification of mercury- bearing effluent from a chloralkali works.
In the foam fractionation experiments, mercury (II) removal up to 99% was obtained with initial mercury (II) concentrations of 0.1 mg dm3 and in the presence of cationic surfactants in suitable excess.· Factors affecting removal of mercury (II) in batch, continuous and semi -continuous modes has been studied including the effect of gas flow rate, surfactant concentra and pH. In precipitate flotation studies, the removal of mercury (II) was increased to around 95% by incorporation of suitable collectors, poly­electrolyte and surfactants and by optimising the pH.
The cold vapour atomic absorption spectrophotometric method for mercury determination was adapted to provide a sensitive and reproducible measure of mercury concentration in samples and interference effects were al so studied. On incorporation of an interface and microcomputer system direct measurements were obtained for peak height and also for peak area.