In the inland region of Southern California, a 116-km brine line distribution system transports brackish desalination brine to the coast for treatment and ocean discharge, however, solid precipitation and pipeline scaling occurred in the brine line. This case study investigated brine chemistry and solid precipitation behaviors. Brine chemical composition at multiple sites along the brine line was measured and the theoretical type and amount of solid formation was predicted using chemical modeling. Lab-scale simulation experiments were performed to evaluate the impacts of antiscalant and flow turbulence on solid formation in the brine. Sampling data showed that pre-existing solids discharged from inland brackish desalination plants accumulated in the brine line which may lead to scaling problem. Chemical modeling predicted that calcite, dolomite, silica and hydroxyapatite were oversaturated and has high potential to precipitate. Lab simulation data suggested that the delayed solid formation was mostly due to the presence of antiscalants, especially secondary antiscalants in low flow turbulence conditions. Results suggests that to minimize scaling issues in the brine line infrastructure, two strategies of active on-site brine pretreatment to remove antiscalants and hardness ions, and operational optimization on the brine line for better flow control and real-time monitoring should be considered and will be examined in the future.

Inland desalination brine disposal: A baseline study from Southern California on brine transport infrastructure and treatment potential

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.