Optimum conditions of zinc removal by Hapalosiphon hibernicus.  
Torit, J., Inthorn, D., Incharoensakdi, A. and Thiravetyan, P.
Journal : Thai Environmental Engineer Journal, 23(3):179-188.
The optimum conditions of zinc removal by using Hapalosiphon hibernicus cells immobilized on polyethylene terepthalate and synthetic fiber and free cells system. These included effects of initial pH, initial cell amount, contact time, zinc concentration and zinc adsorption at equilibrium were studied. The results showed that optimum initial PH were 5-9 and optimum cell amount was 0.015 g dry wt. Immobilized cells on polyethylene terepthalate and synthetic fiber and the free cells system had the highest uptake at 311.53, 253.57 and 258.71 mg Zn/g dry wt., respectively and in all systems reached equilibrium at 90 minutes. Initial zinc concentration at 50 mg/L had the highest zinc uptake. Zinc adsorption of Hapalosiphon hibernicus was fitted to the Langmuir isotherm equation. The maximum adsorption capacity (qmax) and the binding constant (kb) of zinc were 59.25 mg/g dry wt. and 0.36, respectively. The uptake of zinc increased with increasing zinc concentrations. From these results, Hapalosiphon hibernicus is efficient in zinc removal in natural water or canals contaminated with low concentrations of zinc.