Addition of copper-sequestering agents to alginate gel to enhance copper recovery from aqueous media

A mixture of sodium alginate and sodium polystyrenesulfonate (NaPSS) was used as the absorbent for copper in this work. A viscous solution of the mixture was dispensed into a copper-containing solution circulating in a loop fluidized bed reactor to form alginate gel in situ. Batch absorption data was treated by Langmuir model to yield copper binding capacity and binding stability constant. Results were compared with those of our previous work in which no NaPSS was added to Na-alginate. Based on the Langmuir parameters, the critical copper concentration above which the addition of NaPSS can enhance the copper loading of the alginate gel was calculated. The ratio of copper loading of the alginate gel with the addition of NaPSS to that without the addition of NaPSS at any copper concentration was predicted as well. Similar calculations were made for the case of using the mixture of Na-alginate and Microcystis as the copper absorbent.