Terrestrial humics

Stuermer, D. H. and Payne, J. R. (1976). Investigation of seawater and terrestrial humic substances with carbon-13 and proton nuclear magnetic resonance. Geochim. Cosmochim. Acta 40,1109-1114. 

Kogut, M. B. and Yoelker, B. M. (2001). Strong copper-binding behaviour of terrestrial humic substances in seawater, Environ. Sci. TechnoL, 35, 1149-1156. 

Bollag JM (1983) In Christman RF, Gjessing ET (eds) Aquatic and terrestrial humic materials. Ann Arbor Sci Publ, Ann Arbor, Michigan, p 33... 

The most striking characteristic of the dissolved humic substances is their chromophoric nature. As part of the DOM, they impart a yellow-brown cast to marine and freshwaters and, hence, are part of the CDOM pool. Terrestrial hiunic substances compose a significant fraction of the riverine DOM entering the ocean. In seawater, humic substances compose 5 to 15% of the HMW DOM. Differences exist in the bulk properties of marine and terrestrial humic substances. These are summarized in Table 23.6. They have been used to trace the fate of terrestrial organic matter in the ocean. 

Aquatic conditions favor greater hydrogen contents Terrestrial humic compounds have generally low concentrations of hydrogen... 

Fig. 1.9 Terrestrial humic acid model (a) tetramer open form and (b) trimer trapping an additional monomer (Schulten, 2001)...

R. F. Christman and E. Gjessing (eds.), Aquatic and Terrestrial Humic Materials , Ann Arbor Science, Ann Arbor,... 

More than 100 organochlorines have been identified and structurally characterized in the laboratory chlorination of terrestrial humic acid, although the major products are chloroform and trichloroacetic acid, followed by dichloroacetic acid and chlorinated C-4 dicarboxylic acids (324). In addition, other products that form in the chlorination of both humic acid and the model compound 3,4-dihydroxybenzoic acid are shown in Scheme 3.11. A more recently discovered source of natural organically bound chlorine is peat, reaching to 0.2% of the dry weight, and estimated to have accumulated globally to the extent of 280-1,000 million tons (169). 

Tipping (1981) showed that the adsorption of terrestrial humic substances could reverse the positive electrophoretic mobility of iron oxides. Thus, both terrestrial and marine organics are strong adsorbates, able to reverse zeta potential. 

O Loughlin, E. J., S. J. Traina, and Y. P. Chin. 2000. Association of organotin compounds with aquatic and terrestrial humic ltface substances. Environmental Toxicology and Chemistry 19 2015. 

Hatcher, P. G., Breger, I. A., Dennis, L. W., and Maciel, G. E. (1983). Solid-state 13C-NMR of sedimentary humic substances New revelations on their chemical compostion. In Aquatic and Terrestrial Humic Materials, Christman, R. F., and Gjessing, E. T., eds., Ann Arbor Science, Ann Harbor, MI, pp. 37-81. 

TABLE 14.1. Marker Signals in Py-FIMS of Aquatic and Terrestrial Humic Substances, Soil Fractions, and Whole Soils... 

Schulten, H.-R. (1987). Pyrolysis and soft ionization mass spectrometry of aquatic/terrestrial humic substances and soils. J. Appl. Anal. Pyrolysis 12,149-186. 

Th fall of the Orgueil meteorite in 1864 enabled various scientists to confirm the previous observations once again. Cloez noted in 1864 the remarkable similarity between the elementary composition of the terrestrial humic substances and that of the carbonaceous matter in the Orgueil meteorite . 

Shuman, M.S., Collins, B.J., Fitzgerald, RJ. and Olson, D.L. (1983) Distribution of stability constants and dissociation rate constants among binding sites on estuarine copper-organic complexes rotated disk electrode studies and an affinity spectrum analysis of ion-selective electrode and photometric data. In Aquatic and Terrestrial Humic Materials (eds Christman, R.F. and Gjessing, E.T.). Ann Arbor Science, Ann Arbor, MI, pp. 349-370. 

Sea water contains a much lower concentration of dissolved organic matter than river water. More than half of this dissolved organic load is of a humic nature. These dissolved organic acids tend to flocculate as the salinity increases (10). Hair and Bassett (11) have observed an increase in the particulate humic acid load of an estuary as one approaches the sea. Although no studies of the distribution of humic materials throughout an estuarine system have been performed, it would appear that estuaries and their sediments in particular, act as a major sink for the dissolved and particulate humic materials. Nissenbaum and Kaplan (12) have observed that terrestrial humic materials are not deposited at great distances from shore in the marine system. A study of the flux of particulate carbon through the Chesapeake Bay comes to a similar conclusion (13). 

Esterification should be as facile as with a free fatty acid, unlike terrestrial humic substances (Schnitzer and Khan, 1972). 

FIGURE 7. Acidic functional groups in marine and terrestrial humic acids.. After Hue et al. (1974). 

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