Abstract
An addition method of hydoxylammonium chloride in wastewater containing mercury was examined experimentally as a new tertiary treatment to remove mercury by adsorption operation with regenerable chelate resins prepared for heavy metals. It was found that the amount of mercury adsorbed by the resins and the adsorption rate were increased by addition of 0.05-0.1w·v-1% of hydroxylammonium chloride in the wastewater and by adjustment of pH between 3.0-4.0. By the batchwise experiment in which initial concentration of mercury was 1.0mg·1-1, an addition ratio of hydroxylammonium chloride was 0.1w·v-1%, adjusted pH was 4.0 and weight of resins was 1.0g, the concentration of mercury observed at equilibrium was 0.03mg·1-1 but the other side the concentration of mercury without hydroxylammonium chloride was 0.31mg·1-1. And the time to reach at the equilibrium was one third the time obtained without hydroxylammonium chloride. Larger amount of adsorption and higher adsorption rate were also observed by columnwise experiment.
It was more better to use two types of resins equivalently which have calcium-and hydrogen-form respectively. Active carbon was the most profitable as an adsorbent for the post-treatment of hydroxylammonium chloride and the adsorption ratio was 1.1g·g-carbon-1.
