Adsorption of potassium ions from vinasse

Vinasse is the principal liquid waste effluent resulting from alcohol distillation unit, caused by beet or cane molasses fermentation. Increasing awareness of environmental issues in recent years has resulted in a number of technologies being applied for the vinasse treatment as it contains high COD, BOD and mineral nutrients. A possibility of producing the potassium sulfate fertilizer in the form of solution was investigated by adsorption of potassium ions from vinasse and then eluting the latter by sulfuric acid solution. Vinasse was passed through strong acid cation exchange resins columns which adsorb potassium ions. Three technique of adsorption were used (Batch, Semi batch, and Fixed bed). Desorption of potassium was performed using H2SO4 solution forming potassium sulfate solution (15 % conc.), which could be used as a fertilizer, while the remaining vinasse free-potassium can be used in animal feed preparation. It was observed that the adsorption capacity increases by increasing the flow rate, decreasing of initial concentration and decreasing temperature. The highest desorption capacity was achieved at 0.4M sulfuric acid solution and temperature of 35oC.