Environmental

Oral

397323 - Disinfection by-product formation in combined sewer overflow under wet weather conditions

Author(s)

• FD

  Fiona Dunn

  PhD Student
  New York University

Co-Author(s)

• JW

  Jessica Wilson, PhD

  Assistant Professor
  Manhattan College

Co-Authors: Jessica Wilson, Riverdale, NY – Manhattan College

Disinfection of combined sewer overflow (CSO) effluent is necessary to protect surface water sources but can lead to the formation of carcinogenic disinfection by-products (DBPs). For CSOs, higher chlorine doses and/or longer contact times may be needed to meet bacterial effluent requirements. The objective of this work is to determine the DBPs formed at the minimum chlorine dose and contact time that would result in CSO effluent meeting current and proposed bacterial requirements for two facilities with different water quality characteristics. The dominant DBP species that formed were HAAs, which showed higher concentrations at higher initial chlorine doses. HANs were only found after chlorination of influent that had higher NH3 concentrations, likely caused by the formation of chloramines. Both facilities were able to meet the current and proposed bacterial requirements at a chlorine dose of 6 mg/L and a contact time of 15 minutes.