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

1980 ◽  
Vol 37 (3) ◽  
pp. 415-423 ◽  
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

Sources of CO2for Nuisance Blooms of Algae

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 492-497 ◽  
Author(s):  
Claude E. Boyd
Keyword(s):  
Organic Matter ◽  
Algal Blooms ◽  
Algal Growth ◽  
Pond Water ◽  
Equilibrium System ◽  
Nitrogen And Phosphorus ◽  
Decomposition Of Organic Matter ◽  
High Alkalinity ◽  
Algal Photosynthesis ◽  
Nuisance Algal Blooms

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.

Rapid Communication / Communication RapideAmbient solar ultraviolet radiation and its effects on phosphorus flux into boreal lake phytoplankton communities

2002 ◽  
Vol 59 (7) ◽  
pp. 1090-1095 ◽  
Author(s):  
Paul C Frost ◽  
Marguerite A Xenopoulos
Keyword(s):  
Ultraviolet Radiation ◽  
P Uptake ◽  
Boreal Lakes ◽  
Particulate Phosphorus ◽  
Experimental Lakes Area ◽  
Solar Ultraviolet Radiation ◽  
Variable Effect ◽  
Phytoplankton Communities ◽  
P Flux ◽  
P Addition

We examined the effects of ultraviolet radiation (UVR) on net phosphorus (P) flux into phytoplankton communities in two boreal lakes at the Experimental Lakes Area (ELA), Canada. We manipulated P available to and irradiance received by phytoplankton during four different three-day incubations of dilution bioassays. Net P flux was estimated by measuring the accumulation of particulate P (that retained on glass fiber filters) over the incubation period. No effects of UVR on net P flux were found at ambient P levels in any of the experiments. At the highest levels of P addition, less particulate phosphorus (PP) accumulated in both the minus-UVB (~15–40%; photosynthetically active radiation (PAR) + UVA) and full-sunlight (~25–45%; PAR + UVA + UVB) exposed phytoplankton compared with those that received PAR only. Neither chlorophyll- nor carbon-specific net P flux was affected by UVR exposure at ambient P levels. However, at the highest levels of P enrichment, chlorophyll-specific net P flux increased in response to UVR in both lakes, whereas carbon-specific net P flux declined in one of the lakes and was unaffected by UV exposure in the second lake. Our results indicate that UVR can affect total PP accumulation in enriched systems, but not at ambient P levels, and that UVR has a weak and variable effect on biomass-specific P uptake in phytoplankton under enriched conditions.

Periphyton of the Experimental Lakes Area, Northwestern Ontario

1971 ◽  
Vol 28 (2) ◽  
pp. 215-229 ◽  
Author(s):  
John G. Stockner ◽  
F. A. J. Armstrong
Keyword(s):  
Organic Matter ◽  
Chlorophyll A ◽  
Littoral Zone ◽  
Statistical Treatment ◽  
Algal Growth ◽  
Experimental Lakes Area ◽  
Total N ◽  
Algal Group ◽  
Glass Slides ◽  
Significant Difference

The periphyton of four Experimental Lakes Area (ELA) lakes was examined in 1969. The littoral zone of all lakes was composed chiefly of large boulders and rock shelfs and the epilithic algal assemblage was accordingly dominant. Depending directly on light penetration and substrate availability benthic algal growth in most lakes was negligible at depths greater than 10 m. Throughout the growing season diatoms were the dominant algal group within the epilithic assemblage, comprising more than 60–70% of the total algal volume. Filamentous green and blue-green algae increased in importance in July and August but never constituted more than 40% of the volume of the total algal biomass. A well-defined diatom succession was observed both on the natural lithic substrate and on glass slides. Achnangthes minutissima was the most abundant diatom encountered in the littoral zone of all lakes. Periphyton growth on glass slides in lake 240 was 27 mg organic matter/m2∙day during initial colonization and 250 mg organic matter/m2∙day during the period of maximum growth. The vertical distribution of littoral diatoms in lake 240 was examined and differences among species are discussed in light of possible regulating mechanisms. Achnanthes flexella and Eunotia pectinalis were found only in the psammonal habitat of lake 240.Statistical treatment of chemical analyses of N, P, and chlorophyll a content of periphyton showed no significant difference in amounts of total N among periphyton from lakes, but the distribution of both total P and chlorophyll a was significantly different among lakes examined. Highest concentrations of both P and chlorophyll a were found in lakes 239 and 227. In lake 227, a lake receiving weekly additions of N and P, concentrations of P were significantly greater than in the other lakes. Concentrations of N and P/unit organic weight of periphyton taken at a depth of 1 m in each of the study lakes were greatest in lake 227. Comparisons among lakes are made and, based on the results of these comparisons, the role of N and P as regulators of periphyton growth in the ELA lakes is discussed.

Selection of water source for water transfer based on algal growth potential to prevent algal blooms

2021 ◽  
Vol 103 ◽  
pp. 246-254
Author(s):  
Yongjun Song ◽  
Jing Qi ◽  
Le Deng ◽  
Yaohui Bai ◽  
Huijuan Liu ◽  
...  
Keyword(s):  
Algal Blooms ◽  
Algal Growth ◽  
Water Source ◽  
Water Transfer ◽  
Growth Potential ◽  
Algal Growth Potential ◽  
Selection Of

scholarly journals ORGANIC CARBON DYNAMICS IN GRASSLAND SOILS. 1. BACKGROUND INFORMATION AND COMPUTER SIMULATION

1981 ◽  
Vol 61 (2) ◽  
pp. 185-201 ◽  
Author(s):  
J. A. VAN VEEN ◽  
E. A. PAUL
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Experimental Studies ◽  
Decay Rates ◽  
Background Information ◽  
Plant Residues ◽  
Decomposition Rates ◽  
Straw Decomposition ◽  
Soil Biomass ◽  
The World

The decomposition rates of 14C-labelled plant residues in different parts of the world were characterized and mathematically simulated. The easily decomposable materials, cellulose and hemicellulose, were described as being decomposed directly by the soil biomass; the lignin fraction of aboveground residues and the resistant portion of the roots entered a decomposable native soil organic matter. Here it could be decomposed by the soil biomass or react with other soil constituents in the formation of more recalcitrant soil organic matter. The transformation rates were considered to be independent of biomass size (first–order). Data from 14C plant residue incorporation studies which yielded net decomposition rates of added materials and from carbon dating of the recalcitrant soil organic matter were transformed to gross decomposition rate constants for three soil depths. The model adequately described soil organic matter transformations under native grassland and the effect of cultivation on organic matter levels. Correction for microbial growth and moisture and temperature variations showed that the rate of wheat straw decomposition, based on a full year in the field in southern Saskatchewan, was 0.05 that under optimal laboratory conditions. The relative decay rates for plant residues during the summer months of the North American Great Plains was 0.1 times that of the laboratory. Comparison with data from other parts of the world showed an annual relative rate of 0.12 for straw decomposition in England, whereas gross decomposition rates in Nigeria were 0.5 those of laboratory rates. Both the decomposable and recalcitrant organic matter were found to be affected by the extent of physical protection within the soil. The extent of protection was simulated and compared to data from experimental studies on the persistence of 14C-labelled amino acids in soil. The extent of protection influenced the steady-state levels of soil carbon upon cultivation more than did the original decomposition rates of the plant residues.

Algal blooms modulate organic matter remineralization in freshwater sediments: A new insight on priming effect

2021 ◽  
pp. 147087
Author(s):  
Yarui Wang ◽  
Muhua Feng ◽  
Jianjun Wang ◽  
Xinfang Chen ◽  
Xiangchao Chen ◽  
...  
Keyword(s):  
Organic Matter ◽  
Algal Blooms ◽  
Priming Effect ◽  
Freshwater Sediments

scholarly journals Simulating microbial degradation of organic matter in a simple porous system using the 3-D diffusion-based model MOSAIC

2014 ◽  
Vol 11 (8) ◽  
pp. 2201-2209 ◽  
Author(s):  
O. Monga ◽  
P. Garnier ◽  
V. Pot ◽  
E. Coucheney ◽  
N. Nunan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Organic Matter ◽  
Water Content ◽  
Microbial Degradation ◽  
Diffusion Processes ◽  
Pore Space ◽  
High Water Content ◽  
Porous System ◽  
Micro Computed Tomography ◽  
Bacterial Strains

Abstract. This paper deals with the simulation of microbial degradation of organic matter in soil within the pore space at a microscopic scale. Pore space was analysed with micro-computed tomography and described using a sphere network coming from a geometrical modelling algorithm. The biological model was improved regarding previous work in order to include the transformation of dissolved organic compounds and diffusion processes. We tested our model using experimental results of a simple substrate decomposition experiment (fructose) within a simple medium (sand) in the presence of different bacterial strains. Separate incubations were carried out in microcosms using five different bacterial communities at two different water potentials of −10 and −100 cm of water. We calibrated the biological parameters by means of experimental data obtained at high water content, and we tested the model without changing any parameters at low water content. Same as for the experimental data, our simulation results showed that the decrease in water content caused a decrease of mineralization rate. The model was able to simulate the decrease of connectivity between substrate and microorganism due the decrease of water content.

Electricity generation through a photo sediment microbial fuel cell using algae at the cathode

2017 ◽  
Vol 76 (12) ◽  
pp. 3269-3277 ◽  
Author(s):  
B. Neethu ◽  
M. M. Ghangrekar
Keyword(s):  
Power Generation ◽  
Organic Matter ◽  
Microbial Fuel Cells ◽  
Carbon Capture ◽  
Algal Growth ◽  
Oxygen Demand ◽  
Sediment Organic Matter ◽  
Overlying Water ◽  
Organic Matter Removal ◽  
Removal Efficiencies

Abstract Sediment microbial fuel cells (SMFCs) are bio-electrochemical devices generating electricity from redox gradients occurring across the sediment–water interface. Sediment microbial carbon-capture cell (SMCC), a modified SMFC, uses algae grown in the overlying water of sediment and is considered as a promising system for power generation along with algal cultivation. In this study, the performance of SMCC and SMFC was evaluated in terms of power generation, dissolved oxygen variations, sediment organic matter removal and algal growth. SMCC gave a maximum power density of 22.19 mW/m2, which was 3.65 times higher than the SMFC operated under similar conditions. Sediment organic matter removal efficiencies of 77.6 ± 2.1% and 61.0 ± 1.3% were obtained in SMCC and SMFC, respectively. With presence of algae at the cathode, a maximum chemical oxygen demand and total nitrogen removal efficiencies of 63.3 ± 2.3% (8th day) and 81.6 ± 1.2% (10th day), respectively, were observed. The system appears to be favorable from a resources utilization perspective as it does not depend on external aeration or membranes and utilizes algae and organic matter present in sediment for power generation. Thus, SMCC has proven its applicability for installation in an existing oxidation pond for sediment remediation, algae growth, carbon conversion and power generation, simultaneously.

scholarly journals Phosphorus dynamics in the water of tropical semiarid reservoirs in a prolonged drought period

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Herika Cavalcante ◽  
Fabiana Araújo ◽  
Vanessa Becker
Keyword(s):  
Water Column ◽  
Organic Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Semiarid Region ◽  
Drought Period ◽  
Chl A ◽  
Dissolved Phosphorus ◽  
Phosphorus Dynamics ◽  
Prolonged Drought

Abstract Aim To verify the vertical distribution of phosphorus in the water and to identify the predominant forms of P in the water column for understand the phosphorus dynamics in tropical semiarid reservoirs during a prolonged drought period. Methods Two reservoirs from the semiarid region of Rio Grande do Norte were analysed during the period from May 2015 to June 2016. Were analysed: Suspended solids (SS), chlorophyll a (Chl-a), dissolved oxygen (OD) and temperature. Vertical profiles were plotted for total phosphorus (PT), total dissolved phosphorus (PTD), particulate phosphorus (PP), dissolved organic phosphorus (POD) and soluble reactive phosphorus (FRS). Results The phosphorus values distributed in the water column were high for both reservoirs, presenting the highest values during the periods with lower depth. Gargalheiras presented greater predominance of PT and PP, while Cruzeta had the highest values of FRS. Chl-a and SS values were also consistent with phosphorus values: Chl-a was higher in Gargalheiras, while SS, mainly inorganic, were higher in Cruzeta. Gargalheiras presented anoxic conditions close to the sediment from May 2015 to December 2015, which may induce the release of phosphorus from the sediment to the water column. Values that are too high during the shallower months, especially in Cruzeta, may have been influenced by the release of P from sediment through wind resuspension. Conclusions The amounts and predominant types of phosphorus in the water column are of great importance to understand the phosphorus dynamics and will support restoration plans for the studied environments. In this study it was possible to verify that the reservoirs are susceptible to the release of P from the sediment due to the environmental conditions, mainly low depths, resuspension of the wind and anoxia in the hypolimnion.

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