Chemical Oxygen Demand 化學需氧量 English English Wikipedia English ChZT English chemical oxygen demand English chemical oxygen demand English COD English COD English COD index http://en.wikipedia.org/wiki/Chemical_oxygen_demand English English English COD index chemical oxygen demand English English Chemical Oxygen Demand (COD) W Chemical Oxygen Demand (COD) Chemical Oxygen Demand English English chemical oxygen demand English English English English English Chemical Oxygen Demand English English chemical oxygen demand English COD index (COD) English English COD English English English Chemical oxygen demand English Chemical Oxygen Demand English English English English English COD English Chemical oxygen demand