Determination of total organic halides in water

A process for removing purgeable and non-purgeable organic halides from a liquid such as drinking water or wastewater, and for quantitatively determining the concentration of said organic halides in said liquid, said process comprising the steps of:

• a. passing a known quantity of liquid containing organic halides through a packed bed of sorptive material at a flow rate allowing diffusion so that the organic halides are adsorbed and absorbed onto the sorptive material;
• b. thereafter passing a halide ion displacement wash solution through the bed to displace inorganic halides from the sorptive material;
• and
• c. converting the organic halides adsorbed and absorbed by the sorptive material to coulometrically titratable halides, thereby enabling determination of the concentration of organic halides in the liquid,
• the conversion of said organic halides to coulometrically titratable halides being accomplished by an initial heating of said sorptive material with said organic halides adsorbed and absorbed thereon in the presence of a mild oxidant but absence of oxygen to a temperature sufficient to vaporize water therefrom but at a rate of heating insufficient to cause water sputtering, followed by a further heating of said sorptive material with said organic halides adsorbed and absorbed thereon, and of any gases generated by said initial heating, in the presence of an oxidant to a temperature sufficient to cause complete combustion of said sorptive material and generated gases, thereby converting any organic halides present to titratable halides.

A method for converting organic halides in a sample to coulometrically titratable halides, said sample having been pretreated to remove inorganic halides therefrom, said method comprising the steps of:

• (a) heating said sample at a relatively low first temperature to vaporize water and low-temperature volatile organics from said sample, thereby leaving a low-temperature residue;
• said heating at said first temperature occurring at a rate that substantially precludes sputtering of said sample, said water and said low-temperature residue;
• said heating at said first temperature occurring in the presence of a mild oxidant but in the absence of oxygen;
• (b) oxidizing said low-temperature volatile organics at a second temperature, said second temperature being higher than said first temperature, in the presence of an oxidant, whereby any organic halides present in said low-temperature volatile organics are converted to coulometrically titratable halides;
• and
• (c) oxidizing said low-temperature residue at said second temperature in the presence of an oxidant until complete combustion of said low-temperature residue occurs, whereby any organic halides present in said low-temperature residue are converted to coulometrically titratable halides.