Investigation of the causative substances of persistent COD in leachate from marine final disposal sites

Abstract

A survey was conducted at the Kinuura Port No. 3 Area Final Disposal Site to identify the causative substances of persistent COD contained in the leachate from the controlled landfil site, and to consider stable and effective treatment methods.

A questionnaire survey revealed that chelating agents, which have been identified as a source of persistent COD, are used in the waste brought to the disposal site to suppress the leaching of heavy metals.

A water quality analysis using GC/MS confirmed that N,N-diethyldithiocarbamate (DDTC), a type of chelating agent, remains in the leachate for a long period of time without being decomposed.

Since the loss of DDTC during the pre-analytical treatment process and the presence of other COD sources have not understood, future challenges in order to take measures to treat persistent COD is to establish a method for quantifying DDTC in the leachate and to calculate the contribution of DDTC to total COD from the correlation between DDTC and COD.