Determination of Toxic Organic Compounds in Discharge Water from Hydrostatic Testing of Natural Gas Pipelines

摘要

Hydrostatic testing of natural gas pipelines may lead to production of water which is contaminated with organic compounds in a highly complex mixture. Present in the complex mixture are benzene, C-1 to C-5 alkylated benzenes, dimethyl disulfide, C-3 to C-5 alkylated dissulfides, saturated alkanes, and branched/unsaturated alkanes. Estimated minimum concentrations of benzene were 25 to 38 mg/L. In the second study, a complex mixture of polycyclic aromatic hydrocarbons (PAH) and alkylated polycyclic aromatic hydrocarbons was identified and determined quantitatively in discharge water from hydrostatic testing of natural gas pipelines (DWHT). Over 150 PAH or alkylated PAH were detected in portions of DWHT using solvent extraction for prefractionation and concentration. Components were resolved using gas chromatography and identified using gas chromatography/mass spectrometry. Major components included n-alkanes, branched alkanes, alkylated benzenes, and several aromatic hydrocarbons such as substituted naphthalenes and biphenyls.