Sources of CO2for Nuisance Blooms of Algae

Bacterial production of CO2from sucrose substrate increased growth of seven species of algae in CO2-limited laboratory cultures. Decomposition of organic matter in pond water also supplied enough CO2to support good algal growth in cultures deprived of other sources of CO2. Estimates of CO2production from decay of dissolved organic matter in six pond waters ranged from 0.32 to 3.53 mg/L per 24 hr. The carbonate-bicarbonate equilibrium system is a major source of CO2for algal photosynthesis. However, in waters of low or extremely high alkalinity, this system will not support high rates of photosynthesis. In such waters CO2from decomposition will stimulate photosynthesis. Decomposable organic compounds must be considered with nitrogen and phosphorus as factors responsible for accelerated eutrophication and nuisance algal blooms.

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Experimental Studies on the Effect of Arsenic on Microbial Degradation of Organic Matter and Algal Growth

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f80-055 ◽

1980 ◽

Vol 37 (3) ◽

pp. 415-423 ◽

Cited By ~ 9

Author(s):

G. J. Brunskill ◽

B. W. Graham ◽

J. W. M. Rudd

Keyword(s):

Organic Matter ◽

Microbial Degradation ◽

Algal Blooms ◽

Experimental Studies ◽

Algal Growth ◽

Inorganic Arsenic ◽

P Uptake ◽

Particulate Phosphorus ◽

Experimental Lakes Area ◽

Dissolved Phosphorus

Experiments were performed in tubes in Lake 303 at the Experimental Lakes Area to determine the effects of arsenate and arsenite on microbial degradation of organic matter, and to determine rates of reduction and oxidation of inorganic arsenic. Under winter ice, 40 μmol∙L−1 arsenate or arsenite inhibited microbial degradation of organic matter by 50%. Rates of oxidation of arsenite were about 2 μmol∙L−1∙d−1 under aerobic conditions, and rates of reduction of arsenate were about 1 μmol∙L−1∙d−1 under anaerobic conditions. During the ice-free season, arsenate and arsenite had little apparent effect upon rates of degradation of organic matter in lake tubes enriched with nutrients. Rates of formation of particulate phosphorus, and rates of planktonic uptake of dissolved phosphorus were depressed in the presence of arsenic. The observed rate of oxidation of arsenite in summer was similar to the winter value. Arsenate reduction rates ([Formula: see text]30 μmol∙L−1∙d−1) were very rapid under short periods of anaerobiosis. In the presence of large nutrient (N, P) concentrations, As did not inhibit the development of high algal biomass.Based on these experiments, we predict that addition of domestic sewage to arsenate-polluted Kam Lake (near Yellowknife, N.W.T.) will result in a state of restrained eutrophication. Degradation of organic matter will not be inhibited by As in summer, and dissolved phosphorus concentrations will remain high, due to As inhibition of P uptake by the plankton. During the summer, growth of algal blooms may be moderated by As, and more dissolved phosphorus will flow out of the lake to downstream waterbodies.Key words: arsenic, bacteria, algae, organic matter decomposition, eutrophication

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Risk of acidification of the organic shrimp model at Tam Giang commune, Nam Can district, Ca Mau province

Science & Technology Development Journal - Science of The Earth & Environment ◽

10.32508/stdjsee.v1im1.435 ◽

2017 ◽

Vol 1 (M1) ◽

pp. 60-67

Author(s):

Tho Nguyen ◽

Khanh Nguyen Nha Dang ◽

Tu Thi Kim Tran

Keyword(s):

Organic Matter ◽

Pond Water ◽

Depth Range ◽

Alkaline Ph ◽

Wet Season ◽

Pond Sediment ◽

Decomposition Of Organic Matter ◽

Mangrove Soils ◽

Ph Range ◽

Exchange Acidity

This paper assesses the risk of acidification of the organic shrimp model certified by Naturland at Tam Giang commune, Nam Can district, Camau province. Pond water and sediment was sampled in 8 ponds in March, July and November 2015, dike soil and mangrove soils were sampled in March 2015. Pond sediment and mangrove soils are highly reduced (Eh of top sediment and soils to 60 cm depth range respectively from -299 – -1mV and -321 – -52mV). Pond water ranges from neutral to slightly alkaline (pH of pond water 7.01-8.82) and sediment from slightly acidic to slightly alkaline (pH of fresh sediment 6.05-7.64, pHH2O 6.63-7.78, pHKCl 6.35-7.43). Mangrove soils show a large pH range with very low minimums (pHH2O 3.72, pHKCl 3.05), reconfirming the presence of pyrite mineral in the soil profile. Mangrove soils deposited on the dikes (partly oxidized) are very acidic (pHH2O 2.51±0.72, pHKCl 1.81-2.14, exchange acidity 11.56±2.69 meq/100g). At the start of the wet season, pH of pond water reduces sharply as a result of reception of acidic components from the oxidized pyritic material (FeS2) on the dikes. The exchange acidity in pond sediment and mangrove soils are negatively correlated with organic matter, indicating that the decomposition of organic matter under reduced conditions contributes to exchange acidity in pond environment. Risk of acidification of the organic shrimp model is high due to managerial activities (mostly channel digging and disposal of pyrite-containing mangrove soils on the dikes).

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Bacterial response to dissolved organic matter affects resource availability for algae

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f04-229 ◽

2005 ◽

Vol 62 (2) ◽

pp. 472-481 ◽

Cited By ~ 25

Author(s):

Jennifer L Klug

Keyword(s):

Organic Matter ◽

Dissolved Organic Matter ◽

Resource Availability ◽

Inorganic Carbon ◽

Algal Growth ◽

Carbon Limitation ◽

Bacterial Respiration ◽

Photochemical Degradation ◽

Nitrogen And Phosphorus ◽

Bacterial Response

In aquatic systems, the presence of colored dissolved organic matter (DOM) may affect algal growth in numerous ways. This paper focuses on the effects of DOM on resource availability. DOM contains nitrogen and phosphorus, which may become available following microbial or photochemical degradation. Also, addition of DOM may stimulate bacterial growth, which in turn may change the availability of nitrogen, phosphorus, and inorganic carbon to algae. Experiments conducted in a moderately colored lake showed that the effect of DOM on algal growth depended on the amount of nutrients present in the peat extract and on bacterial response to DOM. There was evidence for competition for phosphorus between algae and bacteria in some treatments. In addition, when both bacteria growth and algal growth were high, bacterial respiration of DOM alleviated algal carbon limitation by providing algae with an inorganic carbon source. Thus, the degree to which bacteria are stimulated by the addition of DOM will affect the amount of phosphorus and inorganic carbon available for algal growth. These results suggest that part of the difficulty in predicting algal response to changes in DOM and nutrient concentration may be due partially to variability in bacterial responses.

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Observations on the effect of „Fertosan“- and „QR“- preparations upon the humification of straw

Agricultural and Food Science ◽

10.23986/afsci.71319 ◽

1952 ◽

Vol 24 (2) ◽

pp. 86-92

Author(s):

Armi Kaila ◽

Anha-Meri Pohjanpää

Keyword(s):

Organic Matter ◽

Microbial Population ◽

Experimental Series ◽

Mineral Fertilizers ◽

Nitrogen And Phosphorus ◽

Bacterial Preparation ◽

Laboratory Conditions ◽

Pot Experiments ◽

Decomposition Of Organic Matter ◽

Rye Straw

The effect of the bacterial preparation »Fertosan» and of the possibly biodynamic preparation »OR» upon humification of rye straw was investigated in experimental series both under laboratory conditions and on a larger scale in the field. In all these experiments no evidence indicated that either of these preparations had accelerated the decomposition of rye straw. This could be established under the less favourable conditions in the field composts without mineral fertilizers as well as under the almost ideal conditions in pot experiments where applications of nitrogen and phosphorus were sufficient to satisfy the needs of a large microbial population. Consequently, according to the results of these experiments there seems to be no reason for using such preparations as »Fertosan» and »QR» in humifying rye straw. The decomposition of organic matter seems to depend more on the nitrogen and perhaps even on the phosphorus supply than on an inoculation of some bacteria or on an application of microbial »activators».

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Fish farming in Denmark: environmental impact of regulative legislation

Water Science & Technology ◽

10.2166/wst.1995.0365 ◽

1995 ◽

Vol 31 (10) ◽

pp. 73-84 ◽

Cited By ~ 3

Author(s):

T. M. Iversen

Keyword(s):

Organic Matter ◽

Environmental Impact ◽

Freshwater Fish ◽

Aquatic Environment ◽

Action Plan ◽

Fish Farming ◽

Fish Farms ◽

Nitrogen And Phosphorus ◽

Local Impact ◽

The Impact

The main environmental problems associated with fish farming in Denmark are attributable to the dam, the “dead reach” and nutrient and organic matter discharge. The environmental regulation of fish farming in Denmark started with the Environmental Protection Act of 1974, the Statutory Order of 1985 forbidding wet feed, and the Action Plan on the Aquatic Environment of 1987. In the case of freshwater fish farms, the latter was implemented through the measures stipulated in the 1989 Statutory Order on Fish Farms. The impact of Danish legislative measures to reduce and regulate the environmental effects of freshwater fish farms can be summarized as follows: - the number of fish farms has been reduced from about 800 in 1974 to about 500 at present; - production has tripled since 1974 and has been stable since 1989; - a change from wet to dry feed has reduced the environmental impact of the farms; - the national goals of the Action Plan on the Aquatic Environment of 1987 for reducing fish farm discharges of organic matter, nitrogen and phosphorus have been fulfilled. The main remaining problems are that: - the local impact of fish farms on downstream stream quality is still much too high in about 15% of cases; - the problem of the passage of migrating invertebrates and fish is still unsolved at some farms; - the problems posed by “dead reaches” are still unsolved. It is concluded that sustainable fish farming is possible in Denmark, but with the present technology production will have to be significantly reduced.

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The riverine bioreactor: An integrative perspective on biological decomposition of organic matter across riverine habitats

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.145494 ◽

2021 ◽

Vol 772 ◽

pp. 145494

Author(s):

Ignacio Peralta-Maraver ◽

Rachel Stubbington ◽

Shai Arnon ◽

Pavel Kratina ◽

Stefan Krause ◽

...

Keyword(s):

Organic Matter ◽

Decomposition Of Organic Matter ◽

Riverine Habitats ◽

Biological Decomposition

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Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

Scientific Reports ◽

10.1038/s41598-021-83651-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hidekazu Yoshida ◽

Ryusei Kuma ◽

Hitoshi Hasegawa ◽

Nagayoshi Katsuta ◽

Sin-iti Sirono ◽

...

Keyword(s):

Organic Matter ◽

Early Diagenesis ◽

Ph Change ◽

Carbon Preference Index ◽

Diffusion Growth ◽

Silica Precipitation ◽

Precipitated Silica ◽

Preference Index ◽

Decomposition Of Organic Matter ◽

Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

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