The present invention relates to a process for the preparation of stable iodate-exchanged hydrotalcite with zero effluent discharge. The iodate-exchanged hydrotalcite produced is useful as iodizing agent. The invention further relates to utilization of alkaline effluent generated in the process of ion exchange of iodate into SHT so as to fully recycle the residual iodate anion and also utilize the alkali generated in the process for production of additional quantities of iodate through reaction with iodine crystals followed by electrochemical oxidation to obtain pure aqueous solution of iodate salt which can be reused for preparation of the stable iodizing agent. The process gives zero effluent discharge hence economical.