Dissolved Organic Matter in Lakewater: Characteristics of Molecular Weight Size-Fractions and Ecological Implications

Allen, Harold L.

doi:10.2307/3543433

Cited by 66 publications

(15 citation statements)

References 19 publications

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“…Giesy and Briese (1977) also found Fe to be more concentrated in the larger organic fractions in Okefen0kee swamp water (/zg Fe/mg C). Similarly, Beck and others (1974) found the highest Fe:OC ratio in the largest fraction eluted from Sephadx G-50, and Allen (1976) reported that the greatest Fe binding by organics occurred in the larger molecular weight organics. The higher Fe:OC ratio in the larger fractions may be caused not by more Fe being coordinated by this portion but by the association of colloidal Fe containing particles with the organics in this fraction, which have higher ash contents (Giesy and Briese, 1977).…”

Section: Resultsmentioning

confidence: 99%

Metal binding capacity of selected maine surface waters

Giesy

Briese

Leversee

1978

Geo

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ABSTRACT/Concentrations of Ca, Cd, Cu, Fe, and Pb and binding capacities for Cd, Cu, and Pb were determined for water samples collected from 12 lakes in southwestern Maine using atomic absorption and ion-selective electrodes, respectively. Surface waters in this area are soft and characterized by low pH. Some lakes were highly colored with refractory organics, whereas others had very low organic carbon concentrations. Both Cu and Pb concentrations were positively correlated with organic carbon content. Copper and Pb binding capacities were significantly correlated with organic carbon content, whereas Cd binding capacity was positively correlated with pH, but not with organic carbon. Surface water binding capacity for Pb was greater than that for Cu or Cd. More than 99% of the Ca from all waters studied was removed onto cationic exchange resins. Less than 1% of the total Cu existed as cationic species in highly humic waters, whereas as much as 65% existed as cationic species in less humic waters. Conversely, more than 99% of the Cd present in humic waters existed as cationic species, whereas as little as 50% existed as cationic species in less humic, more alkaline waters. These correlative studies indicate that binding by organic carbon is important for both Cu and Pb in this area and must be considered in models of trace metal speciation. However, Cd binding in the same waters is not correlated with organic carbon, which does not need to be considered in speciation models for Cd.

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Section: Resultsmentioning

confidence: 99%

Metal binding capacity of selected maine surface waters

Giesy

Briese

Leversee

1978

Geo

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“…Allen (1969) noted a direct relationship between the concentrations of DOC and the standing crops of phytoplankton in Lake Lotsjon . However, as Allen (1977) demonstrated, the susceptibility of various molecular weight fractions of the soluble organic pool to bacterial uptake can be very different, and thus there may not necessarily be any direct correlation between heterotrophic activity and total DOC . The parameter Vmax has been found to relate reasonably well with the numbers and activities of heterotrophic bacteria (Allen, 1969) .…”

Section: Discussionmentioning

confidence: 99%

Heterotrophic glucose uptake and respiration in Lake Kinneret

1979

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“…This disparity can probably be explained by the selective uptake of DOC of low molecular weight by bacteria. Studies have shown that bacteria can selectively remove organic molecules of low molecular weight from solution (Ogura 1975;Kaplan 1980) and excrete DOM of higher molecular weight (Nalewajko and Lean 1972;Allen 1976). The DOC increase in White Clay Creek was really a net measurement of algal release, with the DOC of low molecular weight undergoing rapid processing.…”

Section: Discussionmentioning

confidence: 99%

Diel fluctuations of DOC generated by algae in a piedmont stream1

Kaplan

Bott

1982

Limnology & Oceanography

156

117

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Diel fluctuations in dissolved organic carbon (DOC) were measured in White Clay Creek, a piedmont stream in SE Pennsylvania. DOC concentrations, measured on 16 days from late March to early June and on 2 days in early November, 1978 and 1979, showed rapid increases from predawn minima to late afternoon maxima and gradual decreases after sunset. Concentrations increased during a single day by as much as 40% of the daily minimum. These measurements were made during periods of constant discharge and were not related to volume of flow or changes in groundwater DOC concentrations. Laboratory and microcosm experiments suggested that benthic algae excreted most of the DOM and that bacterial uptake modified its concentration and composition. When the diel pulse was strongest, net algal DOC excretion accounted for 20% of the total DOC exported from the watershed that day. Additional data show that the 14C method of measuring algal excretion is quantitatively and qualitatively inaccurate for periphyton incubated for 2–4 h.

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Dissolved Organic Matter in Lakewater: Characteristics of Molecular Weight Size-Fractions and Ecological Implications

Cited by 66 publications

References 19 publications

Metal binding capacity of selected maine surface waters

Metal binding capacity of selected maine surface waters

Heterotrophic glucose uptake and respiration in Lake Kinneret

Diel fluctuations of DOC generated by algae in a piedmont stream1

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