Sorption of Chelating Agents (HEDP and NTA) Onto Mineral Phases and Sediments in Aquatic Model Systems. Part II: Sorption Onto Sediments and Sewage Sludges.
For an ecological assessment of the introduction and fate of organic chelating agents in the aquatic environment, the previously (part I of the article [1]) reported studies on the adsorption of 1-hydroxyethane-1,1-diphosphonic acid (HEDP) and nitrilotriacetic acid (NTA) onto clay minerals were completed with the investigation of the adsorption onto sewage sludges and sediments. The earlier stated results: “high adsorption strength of HEDP, low adsorption of NTA”, were now confirmed again. The FREUNDLICH-adsorption constants “k” for HEDP were typically found in the range between one and two thousand (adsorption onto sediments), whereas the “k”-values of the NTA adsorption onto sediments did not exceed 35.