Rapid Determination of CODcr and Application in Water Purification

Abstract

Rapid COD determination method using spectrophotometry with high-temperature-pressure digestion (SHTP) was designed because COD determination by classic potassium dichromate reflux method (CFM, GB/T 11914-89) had some drawbacks, such unable to analysis in batches, high cost, while had some adverse effect on the environment. SHTP was applied to the study the wastewater quality change of constructed welands for domestic sewage treatment. The results showed that there was a positive correlation between CFM and SHTP (r=0.8801). The linear regression equation between the two methods was CODCFM=1.2198CODSHTP - 4.5745, and the significant test shows no significant difference between the two methods (P=0.07＞0.05). Therefore, the study provided a new and fast method to batch monitoring COD of the sewage water purified.