Chemical Oxygen Demand Analysis of Wastewater Using Trivalent Manganese Oxidant with Chloride removal by Sodium Bismuthate Pretreatment

摘要

Current chemical oxygen demand (COD) analyses generate wastes containing hexavalent and trivalent chromium, mercury, and silver. Waste disposal is difficult, expensive, and poses environmental hazards. A new COD test is proposed that eliminates these metals and shortens analysis time, where trivalent manganese oxidant replaces hexavalent chromium (dichromate). A silver catalyst is not required. Optional pretreatment removes chloride via oxidation to chlorine using Sodium bismuthate, eliminating the need for mercury.