Activated carbon helps in crystallization process and final product is obtained after centrifugation and washing several time and dried at 80 °C. Sodium gluconate may be prepared by gluconic acid through ion exchange.A number of steps are involved like filtration, precipitation, acidification, activated carbon treatment, evaporation and crystallization in conventional downstream purification of gluconic acid as shown in Fig. 3.These processes seem to be quite complex involving energy-intensive and expensive steps releasing huge amount of wastewater and demanding relatively high manpower.The conventional downstream purification system requires harsh chemicals like sulphuric acid, liquid ammonia and other chemicals.Thus gluconic acid extraction process also generates large amount of wastewater leading to environmental pollution [8].For gluconic acid extraction from fermentation broth ion-exchange methods are used.