Precipitated iron and manganese plaques restrict root uptake of phosphorus in Lobelia dortmanna

1998 ◽  
Vol 76 (12) ◽  
pp. 2158-2163 ◽  
Author(s):  
Kasper Kjellberg Christensen ◽  
Kaj Sand-Jensen

Plaques of Fe and Mn on root surfaces of submerged aquatic plants are formed in reduced organic sediments with high concentrations of reduced soluble Fe and Mn. Since oxidized metal compounds have a high capacity for P binding, we grew Lobelia dortmanna L. for 6 months on four sediment types, in which the content of organic matter ranged from 0.32 to 1.73%, to test the influence of plaques on assimilation of P and biomass development. Concentration of oxidized Fe and Mn in plaques on Lobelia roots increased significantly with the content of organic matter in the sediment. Lobelia with high concentrations of Fe in the plaques showed very low tissue content of P and low biomass despite the fact that these plants were from the two organic sediments with high concentrations of P. Plants from the two sediments with low content of organic matter and P showed, in contrast, low plaque concentrations but higher biomass and P content. No significant correlations between the content of Fe and Mn in root plaques and in stems and leaves of Lobelia were found. The results suggest that the formation of plaques on Lobelia roots on sediments rich in reduced Fe and Mn restricts uptake of P and biomass production because P is adsorbed to oxidized Fe and Mn in the plaques.Key words: iron plaque, Lobelia dortmanna, macrophyte, organic matter, phosphorus.


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2051
Author(s):  
Ramón Amigo ◽  
Ana María Méndez-Espinoza ◽  
Andrés R. Schwember ◽  
Jorge Cornejo ◽  
Ricardo Baettig ◽  
...  

Iron (Fe) and manganese (Mn) toxicity is a widespread problem in lentil production in the coastal dryland of Chile. Increasing the soil pH by liming with CaCO3 or incrementing grain yields through nitrogen fertilization can help the plants to reduce metal concentration. Thus, the main objective of this work was to evaluate two different fertilization strategies (lime (CaCO3) and nitrogen (N) additions) to reduce Fe and Mn toxicities in lentils. Lentils grown under field conditions with the highest Fe and Mn concentrations showed toxicity symptoms, but without grain yield reductions. In a pot experiment using the same soil as in the field with toxicity symptoms, the dry matter (DM) produced at the end of the trial was higher in the plants that received N while the lowest DM production was recorded in those plants treated with lime. In particular, higher root DM sustained the growth of the N-fertilized shoots, which also positively affected the grain yields being 33% higher than the control treatment (no fertilization addition). In the plants fertilized with N, the Fe and Mn levels in the shoots were lower than the control plants and those grown in soils treated with lime, but showed higher concentrations of Fe and Mn in roots. In parallel, roots exhibited high concentrations of Fe and Mn that were 13- and 9-fold higher than in the shoots. Additionally, a significant decrease of 29% in Mn concentration in the grains of plants treated with N was reported. Overall, our results suggest that an increase in DM of lentils by the addition of N can reduce the Mn concentration on leaves to a level that is likely under the threshold that causes toxicity in plant tissues. Finally, we conclude that the increase of Fe and Mn in the roots may be connected to the reduction of these metals on leaves.



2009 ◽  
Vol 66 (3) ◽  
pp. 353-360 ◽  
Author(s):  
Jolimar Antonio Schiavo ◽  
Jader Galba Busato ◽  
Marco Antonio Martins ◽  
Luciano Pasqualoto Canellas

Humidified fractions of organic matter and soil microorganism populations are used as environmental quality indicators. This work aimed to study the changes in chemical and microbiological soil attributes, as well as in the humidified fractions, of the organic matter in a substrate from a clay extraction area cropped with Brachiaria mutica, Acacia mangium and Eucalyptus. In the Eucalyptus area, the P contents increased linearly with planting time. However, only at the twelfth year, differences between Eucalyptus and B. mutica areas have occurred. In the A. mangium area, such differences in the P content occurred at the third year with increment of 43%, at the 0-10 cm layer, in relation to B. mutica. Also, at the 0-10 cm layer, the total carbon contents were 98%, 78%, 70% and 40% higher than those found in Eucalyptus with three, five, twelve years of age and in the B. mutica area, respectively. Such increments also occurred in the humidified fractions, especially in the fulvic acids (C FA). The population of microorganisms was higher in the A. mangium area, mainly in the summer, where it was observed a positively correlation with total carbon (total bacteria, r = 0.96**, total fungi, r = 0.91*, and phosphate solubilizer microorganisms, r = 0.98**) and with the C FA fraction (total bacteria r = 0.96**, total fungi, r = 0.90*, and phosphate solubilizer microorganisms, r = 0.98**). The use of A. mangium led to improvements in the chemical and microbiological soil attributes in the substrate



2016 ◽  
Vol 31 (2) ◽  
pp. 21
Author(s):  
Juan P. González -Hermoso ◽  
Emilio Peña -Messina ◽  
Anselmo Miranda -Baeza ◽  
Luis R. Martínez -Córdoba ◽  
María T. Gutiérrez -Wing ◽  
...  

ABSTRACT. The effluents from intensive aquaculture operations such as recirculating aquaculture systems (RAS) have high concentrations of sludge that can become a source of pollution if they are not properly treated and disposed. Anaerobic digestion is commonly used for biological degradation of sludge. Pretreatments prior to anaerobic digestion can enhance sludge degradation and decrease nitrogen and phosphorus load through microbial activity. This study examines the effect of four different pretreatments (biological, chemical, mechanical and thermal) in the N and P fluxes and mass balance from a RAS effluent in a seven-month period at ambient temperature. Each month a 15-day experiment was performed. All pretreatments, except chemical, removed N (thermal 29.78%, biological 36.75%, control 42.25%, mechanical 49.46%, chemical -7.68%). All pretreatments produced phosphorus (chemical 1.96%, mechanical 16.07%, thermal 24.37%, biological 32.39%, control 58.50%). Our results showed that the mechanical pretreatment was the most effective in removing N. In contrast, none of the pretreatments reduced P content in the sludge.Efecto de cuatro pretratamientos en el flujo y balance del nitrógeno y el fósforo en efluentes de un sistema de recirculación acuícolaRESUMEN. Los efluentes de un tipo de cultivo intensivo como los Sistemas de Recirculación Acuícola (SRA) presentan altas concentraciones de lodos que pueden llegar a ser una fuente de contaminación si no son tratados y dispuestos apropiadamente. La digestión anaeróbica es usualmente empleada para llevar a cabo la degradación de los lodos. Los pretratamientos previos a la digestión anaeróbica pueden mejorar la degradación de los lodos, así como reducir la carga de nitrógeno y fósforo a través de la actividad microbiana. Este estudio examinó el efecto de cuatro pretratamientos (biológico, químico, mecánico y térmico) en el flujo y balance de masas de N y P de efluentes de un SRA durante un periodo de 7 meses a temperatura ambiente. En cada mes se llevó a cabo un experimento de 15 días. Todos los pretratamientos a excepción del químico, eliminaron nitrógeno (térmico 29.78%, biológico 36.75%, control 42.25%, mecánico 49.46%, químico -7.68%). Todos los pretratamientos produjeron fósforo (químico 1.96%, mecánico 16.07%, térmico 24.37%, biológico 32.39%, control 58.60%). Nuestros resultados indican que el pretratamiento mecánico fue el más efectivo para eliminar N. En contraste, ninguno de los pretratamientos redujo la concentración de fósforo. 



2021 ◽  
Vol 8 ◽  
Author(s):  
Jinghui Fang ◽  
Wei He ◽  
Shan Meng ◽  
Zengjie Jiang ◽  
Jianguang Fang ◽  
...  

The selectivity of Perinereis aibuhitensis larvae on different sediment types was studied using an experimental behavioral device in the lab. There were six types of sediment with different organic matter content: 2.19, 2.30, 2.86, 3.25, 3.51, and 5.52%. The results indicated significant differences in the six treatments’ organic matter content (p < 0.05). When the P. aibuhitensis larvae initially attached to the sediment, the larvae’s density showed no significant difference among the six treatments. The density of larvae decreased gradually during the experimental period. It increased with the increasing organic matter content in sediment at every sampling time, but there was no significant difference (p > 0.05). The larvae’s specific growth rate in the first month was significantly higher than those in the second and third months (p < 0.05). The mortality showed no significance at different sediments in equal sampling times, but the mortality was lower in high organic matter content sediments. This study showed that the P. aibuhitensis larvae did not make an active selection; random selection happened when initially attached to the sediment with different organic matter contents. Higher organic matter content in the sediment was more conducive to larvae survival, and the organic matter content is the limitation factor on the mortality and the density. The different densities in the natural habitat of P. aibuhitensis might occur due to the passive selection by the environment.





Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3059
Author(s):  
Diogo Folhas ◽  
Armando C. Duarte ◽  
Martin Pilote ◽  
Warwick F. Vincent ◽  
Pedro Freitas ◽  
...  

Thermokarst lakes result from the thawing of ice-rich permafrost and are widespread across northern landscapes. These waters are strong emitters of methane, especially in permafrost peatland regions, where they are stained black by high concentrations of dissolved organic matter (DOM). In the present study, we aimed to structurally characterize the DOM from a set of peatland thermokarst lakes that are known to be intense sites of microbial decomposition and methane emission. Samples were collected at different depths from three thermokarst lakes in the Sasapimakwananisikw (SAS) River valley near the eastern Hudson Bay community of Kuujjuarapik–Whapmagoostui (Nunavik, Canada). Samples were analyzed by spectrofluorometry, Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and elemental analysis. Fluorescence analyses indicated considerable amounts of autochthonous DOM in the surface waters of one of SAS 1A, indicating a strong bioavailability of labile DOM, and consequently a greater methanogenic potential. The three lakes differed in their chemical composition and diversity, suggesting various DOM transformations phenomena. The usefulness of complementary analytical approaches to characterize the complex mixture of DOM in permafrost peatland waters cannot be overlooked, representing a first step towards greater comprehension of the organic geochemical properties of these permafrost-derived systems.



1993 ◽  
Vol 27 (11) ◽  
pp. 193-199 ◽  
Author(s):  
S. Beulker ◽  
M. Jekel

The formation of chlorinated organic substances in bleachery effluents of pulp mills is avoided by changing the bleaching processes to nonchlorinating agents. However, high concentrations of poorly biodegradable and colored lignins are remaining. Precipitation can be one option in physico-chemical treatment of these waters. The influence of alum, lime and magnesium hydroxide as precipitation agents for two different bleachery wastewaters was investigated under various conditions. Alum prove to be the most effective precipitant. Application at an Al/DOC-ratio of 0.5 (g/g) yields a reduction of about 60 % of the soluble organic matter in chlorine-bleachery effluents at the pH = 5.5. Oxygen-bleachery effluents require only half of this specific dosage. Lime precipitation also causes low residual concentrations, but the high chemical demand leads to problems in application. The precipitation with magnesium hydroxide cannot be applied, because remaining concentrations of organic materials are quite high. The changes in bleaching processes are responsible for a new kind of wastewater, which has a significantly lower demand of precipitant



The physiology and morphology of iron- and manganese-depositing flagellates are investigated by means of cultural experiments, with special reference to Anthophysa vegetans Stein, Siderodendron manganiferum n.gen., n.sp., Siphomonas Fritschii n.gen., n.sp. and Bikosoeca ( Poteriodendron ) petiolata (Stein) n.comb. Anthophysa multiplies in various liquid media containing small amounts of organic substances, hay decoction being specially favourable. Still better results are achieved with soil-water cultures, which afford the only successful cultures of Siderodendron and Siphomonas , while Bikosoeca also grows well in hay infusions. Addition of Fe" and Mn" is essential. The brown colour of biological iron deposits is shown to be due to admixture of manganese compounds, while mere ferric precipitates are in microscopical amounts almost colourless. Anthophysa and Siderodendron deposit more manganese than iron, so that their stalks appear brown, while those of Siphomonas are generally light brown. The envelopes of Bikosoeca are almost entirely composed of ferric compounds and appear colourless or faintly yellowish. All four organisms exhibit various modifications according to the habitat conditions. The formation of stalks and envelopes respectively depends on the availability of the relevant metals in the form of lower oxides, but the organisms here described can also exist without producing these structures. The oxidation of ferrous and manganese compounds is catalysed by the cells of these flagellates, although the role of this process in the cellular metabolism is not known. Nutrition is holozoic, chiefly by ingestion of bacteria. Like other holozoic flagellates these organisms cannot exist in the presence of an abundant bacterial vegetation owing to the resulting lack of oxygen. They thrive in quiet, well-aerated waters, with a small content of organic substances, above zones in which Fe and Mn compounds are reduced and from which ferrous and manganous compounds diffuse to the overlying oxidation zone, where these flagellates deposit Fe"' and Mn'" in a morphologically defined form. ‘Iron’ flagellates generally live in association and competition with iron bacteria of the Leptothrix group, the removal of which produces much better growth. A description of the relevant flagellates and of their appearance under various conditions, as well as diagnoses of Siderodendron and Siphomonas , are given.



1996 ◽  
Vol 33 (10-11) ◽  
pp. 401-408
Author(s):  
Naïla Ouazzani ◽  
Khadija Bousselhaj ◽  
Younes Abbas

The aim of this work was to determine the depuration efficiencies of an infiltration percolation plant to remove organic matter and nutrients (N and P) and to test the effect of treatment by such system on the fertilizer value of wastewater compared to untreated influent and a control (groundwater). Results of investigations carried out over a month of each season showed the high capacity of this depuration system to remove both particulate and dissolved organic matter (TSS 91%, COD 93% and dCOD 89 to 95%) at all season. Nitrogen and phosphorus were more eliminated at winter and summer. At spring they presented a low percent removal efficiency due probably to overloaded influent. Tests consisting in the reuse a raw wastewater (RW), settled wastewater (SW) or completely treated wastewater (FW) for irrigation of (Lolium perenne) plots showed that biomass yield, nutrients (N,P) exported by plants and protein amount in the plants tissue decreased from plots irrigated by (RW) to completely treated wastewater. But all of them were more important than in the control plants (irrigated by groundwater) and exceeded the mean values reported in literature for meadows plants. The amount of nitrogen and P2O5) applied during the irrigation by wastewater, was equivalent or superior to recommanded dose of fertilizer for meadows. The expected meat or milk production showed a promising potentiality to promove the nutritional quality of farm animals food by using treated wastewater.



2003 ◽  
Vol 60 (7) ◽  
pp. 888-896 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish

Relationships between organic matter (OM) compounds and methyl mercury concentrations ([MeHg]) have been examined in littoral and offshore sediments of Lake Lusignan (Québec). The highest [MeHg] were generally found at the sediment–water interface with exceptionally high concentrations at littoral sites (5.8 ± 1.3 ng·g dry weight–1), which were four times more elevated than at offshore sites (1.6 ± 0.77 ng·g dry weight–1). Source-specific fatty acid (FA) biomarkers identified that littoral sediments contained more than twice as much terrestrial and bacterial OM compounds than offshore sediments, whereas the amount of labile algal OM was three times higher at littoral sites. Results indicate that [MeHg] were higher in the presence of labile OM substrates, and the amount of terrestrial OM compounds could not predict [MeHg]. Correlations between [MeHg] and FA of Desulfovibrio desulfuricans (a sulfate-reducing bacterium producing MeHg) could significantly account for 36% of [MeHg] at offshore sites; however, no significant relationships were found at littoral sites. This study illustrates that the microbial dynamics involved in producing and degrading MeHg in lacustrine sediments are complex and cannot be predicted solely by the quantification of FA biomarkers in D. desulfuricans or by biomarkers in the OM itself.



Sign in / Sign up

Export Citation Format

Share Document