Marine ecological impact analysis of residual chlorine emission from LNG transfer station

¹ Laboratory of Waterway Environmental Protection Technology, Tianjin Research Institute for Water Transport Engineering, Tianjin 300456, China
² CCTEG Hangzhou Research Institute Co., Ltd., Hangzhou, Zhejiang, 311201, China

Abstract

During the operation of LNG terminals, sodium hypochlorite was used to prevent Marine organisms from attaching to the equipment, resulting in aquatic life problems caused by residual chlorine discharge. The free residual chlorine in seawater is more toxic to aquatic organisms, and the maximum inhibitory effect on Chlorella growth is shown when the concentration of residual chlorine is 0.20mg/ L. Meanwhile, Chlorella growth is greatly affected by residual chlorine, and the recovery time is longer. The concentrations of zooplankton affected by continuous exposure to chlorine were lower than those affected by intermittent exposure. The effect of residual chlorine on shellfish is relatively small. When the residual chlorine concentration is lower than 1mg/L, shellfish can still open their shells to feed, but the feeding speed decreases.