Colloidal organics

Initial tests of Brownian pumping required the measurement of Th in colloids separated from seawater samples. " Th proved to be an especially useful tracer of colloidal uptake of metal species because of its constant source and relative abundance. Baskaran et al. (1992) and Moran and Buesseler (1992) used cross-flow filtration to separate the colloidal fraction and both studies reported significant (up to 78% of total) " Th in this fraction. Subsequent work largely supported these observations (Moran and Buesseler 1993 Huh and Prahl 1995) and suggested the importance of colloidal organic matter in scavenging Th (Niven et al. 1995). [Pg.468]

Niven SEH, Kepkay PE, Boraie A (1995) Colloidal organic carbon and colloidal dynamics during a coastal phytoplankton bloom. Deep-Sea Res II 42 257-273 Nozaki Y, Thomson J, Turekian KK (1976) The distribution of Pb-210 and Po-210 in the surface waters of the Pacific Ocean. Earth Planet Sci Lett 32 304-312... [Pg.491]

Guo LD, Santschi PH (1996) A critical evaluation of the cross-flow ultrafiltration technique for sampling colloidal organic carbon in seawater. Marine Chem 55 113-127 Guo LD, Wen LS, Tang DG, Santschi PH (2000) Re-examination of cross-flow ultrafiltration for sampling aquatic colloids evidence from molecular probes. Marine Chem 69 75-90 Guo LD, Hunt BJ, Santschi PH (2001) Ultrafiltration behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natnral waters. Water Res 35 1500-1508... [Pg.602]

The secondary treatment is linked to the primary treatment in a typical wastewater treatment plant. It is designed to remove soluble and colloidal organics as well as suspended solids that are not trapped in the primary treatment. The treatment processes employed in this section of the wastewater... [Pg.914]

Holbrook RD, Love NG, Novak JT (2004) Sorption of 17-beta-estradiol and 17 alpha-ethinylestradiol by colloidal organic carbon derived from biological wastewater treatment systems. Environ Sci Technol 38 3322-3329... [Pg.108]

Mineral Colloid-Organic Substance-Microorganism Interactions... [Pg.4]

In the majority of cases, minerals in topsoils are partially covered with organic materials, especially humic substances, which are to a large extent microbially resistant. The most common mode of mineral colloid-organic material-microorganism interactions may be depicted as follows (Theng and Orchard 1995) ... [Pg.16]

Mineral Colloid-Organic Substance-Microorganism Interactions in Relation to Soil Structural Stability... [Pg.21]

Bioavailability of Metals, Nonmetals and Xenobiotics Immobilized on Soil Components, (4) Distribution and Activity of Biomolecules in Terrestrial Systems, (5) Interactions between Soil Microbial Biomass and Organic Matter/Nutrient Transformations, and (6) Impact of Interactions among Soil Mineral Colloids, Organic Matter and Biota on Risk Assessment and Restoration of Terrestrial Ecosystems. There were 2 plenary lectures, 9 invited speakers, 36 oral presentations and 45 posters. Dr. N. Senesi from University of Bari, Italy, presented an IUPAC lecture entitled Metal-Humic... [Pg.359]

Fig. 2.10 Mean colloidal organic matter (COM - zooplankton+phytoplankton+dissolved organic carbon) burden [kmol P/m2], integrated over the uppermost 90 m (euphotic zone).

Fig. 2.13 Mean fraction of DDT bound on detritus (upper panels) and colloidal organic matter (lower panels) in the euphotic zone [%].

$Fig. 2.13 Mean fraction of DDT bound on detritus (upper panels) and colloidal organic matter (lower panels) in the euphotic zone [%].$

In a study of the bioaccumulation of metals as colloid complexes and free ions by the marine brown shrimp, Penaeus aztecus [29] the colloids were isolated and concentrated from water obtained from Dickinson Bayou, an inlet of Galveston Bay, Texas, using various filtration and ultrafiltration systems equipped with a spiral-wound 1 kDa cutoff cartridge. The total colloidal organic carbon in the concentrate was found to be 78 lmgdm 3. The shrimps were exposed to metals (Mn, Fe, Co, Zn, Cd, Ag, Sn, Ba and Hg) as radiolabelled colloid complexes, and free-ionic radiotracers using ultrafiltered seawater without radiotracers as controls. The experiments were designed so that the animals were exposed to environmentally realistic metal and colloid concentrations. [Pg.367]

Figure 6.1. Species around soil particles. CC, day colloid COM, colloidal organic matter. [Pg.133]

Colloids Organic Colloids Inorganic Colloids iron oxyhydroxides... [Pg.42]

Brownawell, B.J. The role of colloid organic matter in the marine geochemistiy of PCBs, Ph.D. Dissertation, Woods Hole-MIT Joint Program. Cambridge, MA. 1986. [Pg.1637]

Electrodialysis Relies on proven technology 85,000 11,000 Membrane fonhng and clogging by residnal colloidal organic matter in gronndwater may reqnire more skill and care than other systems discussed in this application. [Pg.530]

Hence, in principle, we could explain the discrepancies between predicted and observed BAFt values by the reduction of the bioavailability of the compounds caused by sorption to colloidal organic matter present in the culture media. We should note, however, that depending on the nature of the dissolved organic matter (i.e., molecular size distribution, aromaticity, polarity, etc.), the KiDOC value of a compound may vary considerably (see Section 9.4). [Pg.347]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...