Evaluation of enhanced coagulation for the removal of dissolved organic nitrogen and the control of nitrogenous disinfection byproduct formation.

摘要

Enhanced coagulation is widely acknowledged as the best available conventional technology for removal of total and dissolved organic carbon (TOC/DOC) and control of regulated trihalomethane (THM4) and haloacetic acid (HAA5) disinfection byproducts (DBPs). Recent DBP toxicity research has indicated that many nitrogen-containing DBPs (N-DBPs) are more cytotoxic and genotoxic than THM4 and HAA5. The objectives of this study were to evaluate the capacity of enhanced coagulation to remove dissolved organic nitrogen (DON) and to reduce formation of dichloroacetonitrile (DCAN) and dichloroacetamide (DCAM), representative species of two important N-DBP classes. Thirteen raw drinking waters from across the U.S., encompassing the range of TOC and alkalinities within the enhanced coagulation matrix, were investigated. This thesis presents and discusses relationships between observed precursor surrogate measures, DBP formation, and results of treatment by enhanced coagulation, which demonstrate greater removal of DOC and chloroform formation potential compared to removal of DON and the selected N-DBPs.