THE ADSORPTION OF FOUR HERBICIDES BY DIFFERENT TYPES OF ORGANIC MATTER AND A BENTONITE CLAY*

Weed Research ◽  
1969 ◽  
Vol 9 (1) ◽  
pp. 20-26 ◽  
Author(s):  
P. J. DOHERTY ◽  
G. F. WARREN
Keyword(s):  
Organic Matter ◽  
Bentonite Clay ◽  
Different Types

Characterization of atrazine binding to dissolved organic matter of soil under different types of land use

2018 ◽  
Vol 147 ◽  
pp. 1065-1072 ◽  
Author(s):  
Long-Ji Zhu ◽  
Yue Zhao ◽  
Yan-Ni Chen ◽  
Hong-Yang Cui ◽  
Yu-Quan Wei ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Different Types

scholarly journals Influence of bryophyte biomass and organic matter quantity on the abundance and richness of oligochaetes in forest streams with different phytophysiognomies in southeastern Brazil

2016 ◽  
Author(s):  
Luciana Falci Theza Rodrigues ◽  
Felipe Silveira Leite ◽  
Roberto Da Gama Alves
Keyword(s):  
Organic Matter ◽  
Southeastern Brazil ◽  
Tropical Region ◽  
Positive Relation ◽  
Semideciduous Forest ◽  
Different Types ◽  
Ecological Importance ◽  
Forest Streams ◽  
Favorable Conditions ◽  
Seasonal Semideciduous Forest

<p>Aquatic oligochaetes can be found associated with different types of substrates; including bryophytes (mosses and liverworts) adhered to stones in lotic ecosystems. However, little information is available on the association between oligochaetes and bryophytes in tropical region. Therefore, the aims of this study were: to investigate whether the assemblages of oligochaetes respond to variation in the biomass of bryophytes and quantity of particulate organic matter (POM) present on these plants; verify differences in the composition of oligochaetes in streams flowing through areas with two phytophysiognomies (rocky field and seasonal semideciduous forest). The samples were collected from five first-order streams in the southeast of the state of Minas Gerais. Six samples of bryophytes adhered to stones were obtained from each stream. A total of 1586 oligochaetes were collected and 11 taxa were identified, belonging to the families Naididae and Enchytraeidae. The most abundant taxa were <em>Bothrioneurum</em> (37.95%) and Enchytraeidae (33.01%). A positive relation was observed between oligochaete abundance and POM in two streams (Ibitipoca I and Ibitipoca III) and a positive relation was found between oligochaete abundance and bryophyte biomass in one stream (Ibitipoca I). The composition of the fauna varied within and between the phytophysiognomies studied. The results show that the oligochaetes find favorable conditions to establish themselves in bryophytes, evidencing the ecological importance of these plants as habitat for invertebrates.</p>

The duplicity of floc strength

2004 ◽  
Vol 50 (12) ◽  
pp. 63-70 ◽  
Author(s):  
P. Jarvis ◽  
B. Jefferson ◽  
S. Parsons
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Laser Diffraction ◽  
Growth Potential ◽  
Small Scale ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Growth Behaviour ◽  
Different Types ◽  
Floc Strength

The breakage of flocs is dependent upon the strength of the bonds holding the aggregate together. The present work describes the breakage and re-growth behaviour of three different types of floc, these were: 1) coagulant precipitate flocs, 2) turbidity flocs and 3) organic matter flocs. Floc aggregates were exposed to increased levels of shear on a conventional jar tester and the sizes of the flocs were observed dynamically using a laser diffraction instrument. The organic flocs showed most resistance to breakage across the whole range of shears under investigation. The dynamic procedure provided detailed information on particle size distributions (PSD). Large and small scale degradation events could be identified from analysis of the PSD data. All of the flocs under investigation showed little re-growth potential after breakage. The precipitate and organic flocs showed slightly better re-aggregation of the small floc sizes.

scholarly journals Effect of Different Factors on the Adsorption of Phosphamidon on Two Different Types of Indian Soil

1998 ◽  
Vol 16 (8) ◽  
pp. 583-594 ◽  
Author(s):  
Dhirendra Singh
Keyword(s):  
Organic Matter ◽  
Adsorption Isotherms ◽  
Alluvial Soil ◽  
Organic Matter Content ◽  
Clay Content ◽  
Matter Content ◽  
Natural Soil ◽  
Standard Entropy ◽  
Indian Soil ◽  
Different Types

The effect of exchangeable cations (H+ and Na+). autoclaving, organic matter, anionic surfactants and temperature on the adsorption of phosphamidon on two different types of Indian soil was studied. The adsorption isotherms for all the effects/treatments were in close agreement with the Freundlich equation and yielded S-shaped isotherms. The amount of phosphamidon adsorbed in all cases was higher in medium black (silt loam) soil than alluvial soil (sandy loam) and was related to the organic matter content, clay content, CaCO3 content, surface area and cation-exchange capacity of the soils. The adsorption on both types of soil follows the order H+-soil > Na+-soil > natural soil at 10°C > natural soil at 20°C > autoclaved soil > organic matter-removed soil > anionic surfactant > natural soil at 40°C, which was in accordance with the Freundlich constant, KF, and distribution coefficient, Kd, values. The adsorption capacity of phosphamidon for organic matter and clay content for both the soils was evaluated by calculating the Kom and Kc values when it was found that phosphamidon adsorption was better correlated with the clay content than with the orgnic matter content on the basis of adsorption isotherms. Various thermodynamic parameters such as the thermodynamic equilibrium constant (K0), the standard free energy (ΔG0), the standard enthalpy (ΔH0) and the standard entropy (ΔS0) changes have been calculated as a means of predicting the nature of the isotherms.

scholarly journals A critical review of the effect of water storage reservoirs on organic matter decomposition in rivers

2017 ◽  
Vol 25 (2) ◽  
pp. 193-198 ◽  
Author(s):  
John Gichimu Mbaka ◽  
Mercy Wanjiru Mwaniki
Keyword(s):  
Organic Matter ◽  
Litter Decomposition ◽  
Water Storage ◽  
Organic Matter Decomposition ◽  
Effect Of Water ◽  
Storage Reservoirs ◽  
Different Types ◽  
Negative Effect ◽  
Tree Leaf ◽  
Habitat Variables

Organic matter decomposition is vital in sustaining river food webs. However, little is known about the effect of water storage reservoirs on organic matter decomposition in rivers. In this paper, we reviewed and analyzed 37 studies that investigated the effect of man-made reservoirs on organic matter decomposition in rivers. Most studies focused on decomposition of tree leaf litter (54.1%) and macrophytes litter (43.2%), while fewer studies evaluated decomposition of wood (2.7%). Based on qualitative analysis, the effect of small weirs on organic matter decomposition is local and the effect on most habitat variables is minimal. Mean effect sizes (Hedges’ g) for organic matter decomposition were −1.98 for small weirs, −1.31 for small reservoirs, and −0.66 for large reservoirs. This review demonstrates that, in general, reservoirs have a negative effect on litter decomposition. Litter decomposition, an important ecosystem process, is sensitive to impacts of reservoirs in different types of rivers.

scholarly journals THE ASSESSMENT OF CLIMATE CHANGE AND WATERSHED EFFECT ON THE HETEROTROPHIC METABOLISM IN THE LAKE ONEGO ECOSYSTEM

2017 ◽  
Vol 1 ◽  
pp. 140 ◽  
Author(s):  
N. M. Kalinkina ◽  
L. E. Nazarova ◽  
E. V. Tekanova ◽  
P. Yu. Litinsky ◽  
A. I. Sidorova
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Benthic Communities ◽  
Terrestrial Ecosystems ◽  
Water Bodies ◽  
Balance Study ◽  
Climate Conditions ◽  
Different Types ◽  
Heterotrophic Metabolism ◽  
Matter Flow

Lake Onego, as one of the largest water bodies in a humid zone, is the recipient of terrestrial carbon and plays an important role in the global balance of this element. Due to heterotrophic metabolism in the Lake Onego ecosystem, substantial emissions of carbon dioxide from this lake into the atmosphere can be assumed. However, the extent of this phenomenon is still poorly known. As a climate change has led to an increase in water and organic matter flow into the northern water bodies, the carbon balance study of aquatic ecosystems is of particular relevance. The elements of the water balance for the Lake Onego catchment area in the current climate conditions are assessed. Based on satellite images the model of Lake Onego watershed terrestrial ecosystems is used to simulate the flow of organic matter into the lake with different types of vegetation and topography consideration. The assessment of the benthic communities habitat is carried out taking into account the accumulation of organic matter in various parts of Lake Onego.

scholarly journals Characteristics of Phosphorus Adsorption and Release in Different Types of Sediments

2020 ◽  
Vol 8 (05) ◽  
pp. 342-354
Author(s):  
Pengqiang Yang ◽  
Huanghe ◽  
Rujun Gao
Keyword(s):  
Heavy Metal ◽  
Particle Size ◽  
Organic Matter ◽  
Metal Ion ◽  
Organic Matter Content ◽  
Matter Content ◽  
Heavy Metal Ion ◽  
Phosphorus Adsorption ◽  
Different Types ◽  
Adsorption And Release

Taking different types of sediments as the research object, this research studied the adsorption and release characteristics of phosphorus under different conditions of different temperatures, coexisting heavy metal ion system, organic matter content and sediment particle size. Through used correlation analysis and principal component analysis, it discussed the influence of various factors on the adsorption and release of phosphorus in sediments. The results show that the adsorption of phosphorus by five different types of sediments from different sources reached saturation equilibrium in about 10 hours, and the increasing rates of 0 ℃, 15 ℃ and 30 ℃ are 17.5% ~ 23.7% and 18.2% ~ 38.3%, respectively.  The addition of coexisting heavy metal ion solution accelerated the adsorption of phosphorus in the sediment and reduced the total amount of phosphorus adsorption, that is, heavy metal ions inhibited the adsorption of phosphorus in the sediment; the presence of organic matter in the sediment would reduce its adsorption of phosphorus , Taihu farm and wetland sampling points have the largest sediment organic matter content. Compared with the other three points, the adsorption of phosphorus of these two  points accounted for 20.6% and 22.1%; the adsorption and release of phosphorus by sediment increased with the decrease of particle size. The maximum release rate was 5.216mg/kg-1·h-1. The result of principal component analysis shows that the order of influence on the adsorption and release of phosphorus by sediments is temperature> disturbance> organic matter content> heavy metal ion influence> particle size of sediments.

scholarly journals Microbial composition, diversity, and activity varies across different types of basal ice

2021 ◽  
Author(s):  
Shawn M. Doyle ◽  
Brent C. Christner
Keyword(s):  
Organic Matter ◽  
16S Rrna ◽  
Meta Analysis ◽  
Microbial Composition ◽  
Glacial Ice ◽  
Microbiome Composition ◽  
Basal Ice ◽  
Different Types ◽  
Insight Into ◽  
Read Abundance

ABSTRACTBasal ice often contains entrained subglacial debris and sediment which can serve as a source of nutrients and organic matter and provide habitat for microorganisms adapted to frozen conditions. However, basal ice comes in many different forms and comparatively little is known about how microbial composition, diversity, and activity vary across different types of basal ice. Here, we investigated these parameters in four different types of basal ice from two different glaciers and then used a meta-analysis to compare our findings with microbiome studies of other permanently frozen environments. We found microbiome composition varies substantially between basal ice types, even within the same glacier. Further, the microbiomes of sediment-rich basal ices were distinct from those found in glacial ice and instead were most like those found in permafrost. Consistent with this, microbial diversity was also comparable to that found in permafrost and was much higher relative to glacial ice. Patterns of 16S rRNA read abundance from RNA relative to DNA implicated certain taxa as potentially active in basal ice with ice temperature appearing to be an important predictor for the diversity of taxa inferred to be active. Our results improve our understanding of the microbial ecology of different basal ice types and provide insight into which types are likely habitats for metabolizing microbial communities.

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