Combining reverse osmosis and electrodialysis for more complete recovery of dissolved organic matter from seawater

Dissolved organic carbon (DOC) in the oceans is one of the largest dynamic carbon reservoirs on earth. The composition and fate of this carbon reservoir is of great interest to earth scientists, atmospheric scientists, and biologists who study global biogeochemical cycles and global warming. Current techniques for the extraction and purification of dissolved organic matter (DOM) from seawater for research purposes recover at best only 30 wt% of DOC. A new technique for the recovery of DOM from seawater has been developed by combining electrodialysis and reverse osmosis. Here we present shipboard results and laboratory work to show the feasibility of our technique. DOC recoveries exceeding 60% and even exceeding 90% for one seawater sample have been found. Analysis of samples recovered using this technique will yield new insights into the cycling of DOC in the oceans.