scholarly journals Oxygen Transfer Capacity as a Measure of Water Aeration by Floating Reed Plants: Initial Laboratory Studies

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1270
Author(s):  
Antonio Albuquerque ◽  
Peter Randerson ◽  
Andrzej Białowiec

Reed-Phragmites australis (Cav.) Trin. ex Steud, an aquatic plant, commonly used in constructed wetlands for wastewater treatment, supplies oxygen into the subsurface environment. Reed may be used as a ‘green machine’ in the form of a floating vegetation cover with many applications: wastewater lagoons, manure lagoons or sewage sludge lagoons. An important measure of the performance of the plant system is the oxygen transfer capacity (OTC). Accurate prediction of the OTC in relation to reed biomass would be crucial in modelling its influence on organic matter degradation and ammonia–nitrogen oxygenation in such lagoons. Laboratory experiments aiming to determine OTC and its dependence on reed biomass were carried out. Eight plants with a total dry mass ranging from approximately 3 to 7 g were tested. Mean OTC was determined per plant: 0.18 ± 0.21 (g O2·m−3·h−1·plant−1), with respect to leaves-and-stem dry mass (dlsm): 44.91 ± 35.21 (g O2·m−3·h−1·g dlsm−1), and to total dry mass (dtm): 33.25 ± 27.97 (g O2·m−3·h−1·g dtm−1). In relation to the relatively small root dry mass (drm), the OTC value was 136.02 ± 147.19 (g O2·m−3·h−1·g drm−1). Measured OTC values varied widely between the individual plants (variation coefficient 115%), in accordance with their differing size. Oxygenation performance was greatest in the reed plants with larger above ground dry mass (>4 g dlsm), but no influence of the root dry mass on the OTC rate was found.

1994 ◽  
Vol 29 (10-11) ◽  
pp. 471-477 ◽  
Author(s):  
K. Nishidome ◽  
T. Kusuda ◽  
Y. Watanabe ◽  
M. Yamauchi ◽  
M. Mihara

With an oxygen microelectrode developed by the authors for the measurement of dissolved oxygen (DO) concentration profiles of biofilms in a rotating biological contactor (RBC), DO concentration profiles in the inside and outside of rotating biofilms were measured continuously in the air and water phases. Thicknesses of attached-water film (Lw) and the diffusion layer (Ld) formed on the biofilms were estimated from DO concentration profiles. The oxygen transfer rate to the biofilm was determined with measured DO concentration profiles and a steady state biofilm kinetic model by use of the thicknesses of attached-water film and the diffusion layer. The oxygen transfer rates obtained by two independent methods agreed well, so that the method of the measurement of DO concentration profilesis considered highly reliable. The conclusions in this study are summarized as follows: (1) Lw and Ld on a biofilm attached on a partially submerged rotating biological contactor were 50 and 70 μm thick, respectively; (2) The measured oxygen fluxes were about 10 g-O2/m2/day, and reasonably agreed with those calculated from removing rates of ammonia nitrogen.


1987 ◽  
Vol 19 (5-6) ◽  
pp. 869-876
Author(s):  
L. Raschid-Sally ◽  
M. Roustan ◽  
H. Roques ◽  
G. M. Faup

A non-conventional aeration system for oxidation ditches using jets has been developed. The principle of this system is based on the separation of the 2 actions: aeration and circulation. It was concluded that the flow of the liquid in the channel can be successfully modelled using various theoretical approaches. The mean circulation velocity VC, the power dissipated P, and the Peclet number Pe are the 3 important parameters governing the circulation. The oxygen transfer capacity of the system has been studied and compares favourably with that of conventional systems. The advantage of such systems over conventional ones has been discussed.


1993 ◽  
Vol 290 (1) ◽  
pp. 145-150 ◽  
Author(s):  
C A Brearley ◽  
D E Hanke

[3H]Inositol and [32P]Pi labelling of the aquatic plant Spirodela polyrhiza L. revealed the presence of PtdIns(3,4)P2, in addition to PtdIns3P, PtdIns4P and PtdIns(4,5)P2 previously identified [Brearley and Hanke (1992) Biochem. J. 283, 255-260]. PtdIns(3,4,5)P3 was not detected. Throughout a 40 min [32P]Pi-labelling period the specific radioactivity of the gamma-phosphate of ATP and of the ATP pool as a whole increased. Chemical and enzymic dissection of phosphoinositides obtained from plants labelled for 35 min with [32P]Pi showed that over 99.7% of the label in PtdIns3P and PtdIns4P was accounted for by the monoester phosphates. The 3- and 4-monoester phosphates of PtdIns(3,4)P2 accounted for 23.1% and 76.6% respectively of the label, whereas the 4- and 5-monoester phosphates of PtdIns(4,5)P2 accounted for 21.1% and 78.6% respectively. These results are consistent with the synthesis of PtdIns(4,5)P2 via PtdIns4P. The labelling of the individual phosphates of PtdIns(3,4)P2 is, however, inconsistent with synthesis from PtdIns(4,5)P2 via PtdIns(3,4,5)P3, but instead suggests that PtdIns(3,4)P2 is synthesized by 4-phosphorylation of PtdIns3P. These results afford the first evidence that in plants in vivo, synthesis of PtdIns(4,5)P2 follows the pathway described in animal cells and also that plants possess PtdIns3P 4-kinase activity similar to that reported from animal cells.


2014 ◽  
Vol 54 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Stefan Gumiński ◽  
Krystyna Jurajda ◽  
Ewa Tatkowska

The increase in total dry mass and protein in cultures of <em>Chlorella pyrenoidosa, Scenedesmus quadricauda</em> and <em>Ankistrodesmus acicularis</em> was studied. Under autotrophic conditions, increases in dry mass were, as a rule, larger in the nitrate medium than in the ammonium one, under mixotrophic conditions the situation was reversed and in the case of heterotrophy, the individual species reacted differently. The dependence ot the protein content increase on the nitrate or ammonium form of the medium was not clear. Changes in time of the pH and rH of the mediums were followed and the interdependence of these changes with the production of biomass is discussed.


Author(s):  
Ega Puspita Famila Boden Junaedi Putri ◽  
Salnida Yuniarti Lumbessy ◽  
Nanda Diniarti

Catfish (Clarias gariepinus.) is one of the leading commodities that are widely cultivated in Indonesia. The current development of the aquaculture industry, which leads to intensive cultivation systems with an increase in stocking and high amount of feed, causes an increase in organic waste that can reduce water quality. Phytoremediation is one way to stabilize pollutants, both organic and inorganic compounds, through aquatic plants. Water hyacinth (Eichornia crassipess) is one aquatic plant that can reduce total nitrogen up to 73.05%. This study aims to analyze the effect of water hyacinth (E. crassipess) as a phytoremediator on TAN reduction, survival rates, and growth of catfish (C. gariepinus) seeds. This study used a Completely Randomized Design (CRD) method with four treatments and four replications, namely P1 / control (without water hyacinth), P2 (without replacement of water hyacinth), P3 (alternation of water hyacinth every 21 days), and P4 (alternation of water hyacinth) every 14 days). The results showed that the P4 treatment (alternation of water hyacinth every 14 days) gave the lowest TAN content 0.01 mg / L and provided the highest survival rate of 89.88%, as well as the absolute weight and length growth of the most catfish seeds height, i.e., 9.80 g, and 5.50 cm, respectively.


2021 ◽  
Author(s):  
Lee Moores ◽  
Stacy Jones ◽  
Garrett George ◽  
David Henderson ◽  
Timothy Schutt

Herein the matrix effects on the kinetics of aqueous photolysis for the individual munitions constituents of IMX-101: nitroguanidine (NQ), dinitroanisole (DNAN), and nitrotriazolone (NTO) are reported along with the environmentally relevant kinetics and quantum yields. Photolysis potentially represents a major degradation pathway for these munitions in the environment and further understanding the complex matrices effects on photolytic kinetics was needed. Aqueous systems are of particular interest due to the high solubility of NQ (3,800 ppm) and NTO (16,642 ppm) compared to the traditional munitions trinitrotoluene (TNT, 100.5 ppm) and 1,3,5-trinitro-1,3,5-triazine (RDX, 59.9 ppm). Environmental half-lives (and quantum yields) were found to be 0.44 days, 0.83 days, and 4.4 days for NQ, DNAN, and NTO, respectively, under natural sunlight. In laboratory experiments using nominally 300 nm bulbs in a merry-go-round style reactor in DI water the relative rate of photolysis for the three munitions constituents followed the same order NQ > DNAN > NTO, where DNAN and NTO reacted 57 and 115 times more slowly, respectively, than NQ. In the various environmentally relevant matrices tested in the laboratory experiments NQ was not significantly affected, DNAN showed a faster degradation with increasing ionic strength, and NTO showed a modest salinity and pH dependence on its rate of photolysis.


2022 ◽  
Vol 7 (1) ◽  
pp. 51-56
Author(s):  
Agáta Fargašová ◽  
Katarína Szárazová

The dry and fresh biomass and metal concentration (Cr, Ni) in roots and shoots of mustard (S. alba L.) seedlings was evaluated in laboratory experiments with three types of washing waste-waters from cutlery production line. All tested washing waters reduced root dry mass, where-as the dry mass of shoots was either not affected or it increased. The effect of tested washing waters was stronger on fresh mass production than on dry mass production. This indicates problems in water reception and translocation. While the accumulation of Cr was higher in the roots, Ni was distributed equally through the whole plant seedling. Cr uptake in the roots and shoots was in average about 1.7 and 7.3 times, respectively, lower than that of Ni. Ni percentage uptake from washing waters in the roots and shoots was nearly equal and range from 10.2 to 15.8%.


2016 ◽  
Vol 34 (4) ◽  
pp. 657-666 ◽  
Author(s):  
F.C. CARATTI ◽  
F.P. LAMEGO ◽  
J.D.G. SILVA ◽  
J.R. GARCIA ◽  
D. AGOSTINETTO

ABSTRACT Plants compete for resources present below and above the soil surface. The objective of this work was to separate the individual effects of the competition for resources between soybean and corn as competitor plants. The experiment was conducted in a greenhouse, in 2014/2015. The treatments consisted of soybean cultivars (TEC 5718 and TEC 6029) in competition conditions with corn (no competition, competition for soil resources, competition for solar radiation and total competition). The variables evaluated were plant height at 7, 14, 21, 28, 35 and 42 days after emergence (DAE), stem/culm diameter, leaf area, shoot dry mass, root dry mass and the chlorophyll index, at 42 (DAE). The competition for soil resources between soybean and corn is pronounced, being that short cultivars with determinate growth habit, such as TEC 5718, invest more in root biomass, specific leaf area and leaf area ratio when in competition. The soybean cultivars do not suppress corn, but allow it to benefit when associated to its root system, increasing the shoot and root dry mass, leaf area and chlorophyll index.


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