Combining submerged membrane technology with anaerobic and ...

Chapter 2where:M fas: molarity of FAS (mol·L -1 ), andV fas: volume of FAS consumed in the titration (mL).The COD is calculated with the following equation 2.2:eq. 2.2where:COD: chemical oxygen demand (mg O 2·L -1 ),A: mL of FAS consumed by the blank,B: mL of FAS consumed by the sample,M fas: molarity of FAS (mol·L -1 ), and8000: milliequivalent weight of oxygen x 1000 mL·L -1 .V: mL of sampleInterferencesThe most common interferent is the chloride ion. Chloride reacts with silver ion toprecipitate silver chloride, and thus inhibits the catalytic activity of silver. Bromide andIodide can interfere similarly.2.1.1.2. Total dissolved carbon (TDC), dissolved organic carbon (DOC) anddissolved inorganic carbon (DIC)The organic carbon in water and wastewater is composed of a variety of organiccompounds in different oxidation states. Some of this carbon compounds can be oxidisedfurther by biological or chemical processes and the biochemical oxygen demand (BOD)and chemical oxygen demand (COD) may be used to characterise these fractions. Totalorganic carbon (TOC) is a more convenient and direct expression of total organic contentthan COD, but does not provide the same information. Unlike COD, TOC is independent ofthe oxidation state of the organic matter and does not measure other organically boundelements, such as nitrogen and hydrogen, and inorganics that can contribute to the oxygendemand measured by COD (APHA-AWWA-WPCF, 1998). To determine the quantity oforganically bound carbon, the organic molecules must be broken down and converted to asingle carbon molecular form that can be measured quantitatively. In this case, the DOC64