PHOTOELECTROCHEMICAL DETERMINATION OF CHEMICAL OXYGEN DEMAND FOR MODEL ORGANIC COMPOUNDS AND RAW AND TREATED SURFACE WATERS

摘要

This study investigated the use of a novel photoelectrochemical chemical oxygen demandrn(peCOD) analyzer for the detection of natural organic matter (NOM) from four drinkingrnwater treatment plants in Nova Scotia, Canada. This method was investigated because itrncan measure NOM within 5 minutes and does not require hazardous reagents. As anrninitial research step, eight model organic compounds were used to demonstraterninstrument feasibility. The study found that peCOD could accurately detect oxygenrndemand based on theoretical chemistry concepts (i.e. theoretical oxygen demand). Thernnext step in the study evaluated NOM removal in practice. Specifically, a drinking waterrnplant survey found that the removal of NOM, as measured by peCOD, was approximatelyrn3.5 times greater than the removal using traditional NOM surrogates (e.g. total organicrncarbon). This expanded scale in resolution highlighted the instrument’s ability to providerndetailed information on treatment performance that were often more subtle withrntraditional NOM techniques.