Preliminary investigation of the association of organic material and carbon dioxide with sedimentary particles

Abstract

The removal of dissolved organic compounds and carbon dioxide from sea water by sedimentary minerals and the subsequent incorporation of both in sedimentary deposits are determined by various environmental factors. The laboratory experiments discussed in this report were devised so as to permit consideration of the effect of type of organic compound, solution concentration, mineralogy, pH, chlorinity, mineral settling rate and temperature on the mineral-organic association in aqueous systems. The investigation was conducted by radiometric analysis with the use of dl-alanine, glycine, aspartic acid, oxalic acid, succinic acid, fructose, glucose ad sucrose, all known to occur in natural waters and deposits. These organic compounds were spiked with their carbon-14 counterpart. The carbon dioxide phase was accomplished in a like manner with the use of spiked carbon-14 dioxide. The minerals under investigation were montmorillonite, illite, kaolinite and quartz, all commonly found in marine deposits. It has been demonstrated that the association of amino acids, dibasic acids and carbohydrates with minerals is primarily dependent upon the molecular weight, structure and functional groups of the compounds as well as upon the available surface area and surface "activity" of the mineral. Impressed on these principal variables are pH, chlorinity and temperature of the system. The total phenomena observed in these experiments can best be explained by the formation of a complex clay-organic gel. The data cannot be explained on the basis of a physical phenomenon alone, and it appears that the triggering for the mechanism forming the complex gel is in part physical and chemical as related to both the organic compound and the mineral. Once the initial system is formed, the growing particles may act as a molecular sieve capable of continuously removing organic material from solution during the settling process..