Microbial Toxicity of Cd and Hg in Different Soils Related to Total and Water-Soluble Contents

1997 ◽  
Vol 38 (3) ◽  
pp. 200-204 ◽  
Author(s):  
Gerhard Welp ◽  
Gerhard W. Brümmer
2007 ◽  
Vol 35 (2) ◽  
pp. 597-600
Author(s):  
Ida Kincses ◽  
Tibor Filep ◽  
Péter Nagy ◽  
Andrea Kovács

2020 ◽  
Vol 175 ◽  
pp. 12022
Author(s):  
Guriyat Podvolotskaya ◽  
Sergey Belopukhov ◽  
Vitaly Savich ◽  
Andrey Sorokin ◽  
Nikolay Tyutrin

Soil solutions and the surface waters are characterized by properties, processes and regimes. Soil solutions of different soils and their surface water have different biological activity and change the activity of dissolved stimulants and inhibitors. The object of the study are soil solutions of the main types of soils obtained in the model experiments with the ratio of soils: water equal to 1:1 and 1: 2, soil solutions and surface water in the flooding of soils with water for 1 week – 3 months. The research method consisted in the assessment of pH, Eh, activity of K, NO3, NH4, Ca, Mg by conventional methods, assessment of concentrations of water-soluble compounds extracted from soils by ionite membranes, in the assessment of biological activity of solutions using biotests. The following is suggested for additional evaluation: the using of cation and anion membranes, determination of interrelation between the properties of waters, equation of pair correlation and multiply regression. The informative value of the gradient of surface water concentrations at different distances from the floor of the reservoir, at different depths of the overwatered soils is shown. The mobility of Ca, Mg, Fe, Mn in soils and the content of their water-soluble forms depends on both pH and Eh, whose influence on the content of water-soluble forms of the considered cations shows the effects of synergy and antagonism. The rate of change in the composition of soil solutions during soil flooding depends on a combination of soil properties, temperature, and duration of flooding. Soil solutions of different soils and their surface waters have differentrates.


2018 ◽  
Author(s):  
Eduardo Moreno Jiménez ◽  
Sara Aceña-Heras ◽  
Vladimir Fristak ◽  
Stefanie Heinze ◽  
Bernd Marschner

The contamination of soils and waters with organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), affect a large number of sites worldwide that need remediation. In this context soils amendments can be used to immobilise PAHs while maintaining soil functioning, with biochar being a promising amendment. In this experiment phenantrene (Phe) was used as a frequent PAH contaminating soils and we studied the effect of three biochars at 1% applications to three different substrates, two agricultural topsoils and pure sand. We evaluated the changes in soil properties, sorption-desorption of Phe, and mineralisation of Phe in all treatments. Phe in pure sand was effectively sorbed to olive pruning (OBC) and rice husk (RBC) biochars, but pine biochar (PBC) was not as effective. In the soils, OBC and RBC only increased sorption of Phe in the silty soil. Desorption was affected by biochar application, RBC and OBC decreased water soluble Phe independently of the soil, which may be useful in preventing leaching of Phe into natural waters. Contrastingly, OBC and RBC slightly decreased the mineralisation of Phe in the soils, thus indicating lower bioavailability of the contaminant. Overall, biochar effects in the two tested soils were low, most likely due to the rather high soil organic C (SOC) contents of 2.2 and 2.8% with Koc values in the same range as those of the biochars. However, OBC and RBC additions can substantially increase adsorption of Phe in soils poor in SOC.


Agropedology ◽  
2019 ◽  
Vol 30 (2) ◽  
Author(s):  
P.C. Srivastava ◽  
◽  
S.P. Pachauri ◽  

Among micronutrients, boron (B) occupies a prime place next to zinc (Zn) in Indian Agriculture. Acidic soils, coarse-textured soils subjected to leaching in high rainfall areas, and calcareous soils are likely to be deficient in B (Srivastava and Gupta 1996). According to an estimate based on soil testing of more than two lakh samples drawn from 508 districts of India indicated that 23.2 percent of soil samples are deficient in B (Shukla et al. 2019). Though there are several methods for the analysis of B in soils yet hot water-soluble B (Berger and Truog 1940; Gupta 1967) or dilute CaCl2 extractable B (Cartwright et al. 1983; Adams et al. 1991) are widely adopted for different soils all over the World (Diana 2008). The assembly adopted for the extraction of hot water soluble or dilute CaCl2 extractable B is costly as it requires the use of low B glass or quartz boiling flask equipped with a condenser tube for refluxing (Parker and Gardner 1981) which generally poses difficulty in handling and maintenance. Schuppli (1986) used a Teflon Erlenmeyer flask (125 ml) capacity attached to a Teflon reflux condenser to extract hot water-soluble B from soils, and an asbestos mat was placed between the hot plate and the flask to prevent damage to the Teflon flask. This publication proposes a low-cost assembly to extract hot water-soluble or hot CaCl2 extractable B in soils.


2021 ◽  
Vol 4 (2) ◽  
pp. 26-35
Author(s):  
Almu H. ◽  
Abdulkadir N.A. ◽  
Sani A. ◽  
Adamu U.K. ◽  
Aminu M.A.

A study was conducted on the distribution of potassium in the surface soil of Kano University of Science and Technology teaching, research and commercial farm, Gaya during 2018/2019 session. The contents of different forms of potassium were observed. Water soluble, exchangeable, non-exchangeable, mineral and total potassium were determined in surface soil (0–15cm) in KUST teaching, research and commercial farm, Gaya. The results showed that the average values for water soluble K, exchangeable K, non-exchangeable K, mineral K and total K were: 0.14, 0.18, 0.35, 1.36 and 3.92 Cmol/Kg soil respectively. The values for K saturation percentage (KSP) ranged between 0.12–019 and exchangeable K between 0.13–0.20 Cmol/Kg clay. There was a wide variation in the values of various forms of K and among indices associated with mineral composition in different soils. The results show that the values of K form in most of the studied soils are quite low. Consequently, the supplying power of potassium in these soils is low and the need for potassium fertilizer is recommended.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5074 ◽  
Author(s):  
Eduardo Moreno Jiménez ◽  
Sara Aceña-Heras ◽  
Vladimír Frišták ◽  
Stefanie Heinze ◽  
Bernd Marschner

The contamination of soils and waters with organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), affect a large number of sites worldwide that need remediation. In this context soils amendments can be used to immobilise PAHs while maintaining soil functioning, with biochar being a promising amendment. In this experiment, phenantrene (Phe) was used as a frequent PAH contaminating soils and we studied the effect of three biochars at 1% applications to three different substrates, two agricultural topsoils and pure sand. We evaluated the changes in soil properties, sorption-desorption of Phe, and mineralisation of Phe in all treatments. Phe in pure sand was effectively sorbed to olive pruning (OBC) and rice husk (RBC) biochars, but pine biochar (PBC) was not as effective. In the soils, OBC and RBC only increased sorption of Phe in the silty soil. Desorption was affected by biochar application, RBC and OBC decreased water soluble Phe independently of the soil, which may be useful in preventing leaching of Phe into natural waters. Contrastingly, OBC and RBC slightly decreased the mineralisation of Phe in the soils, thus indicating lower bioavailability of the contaminant. Overall, biochar effects in the two tested soils were low, most likely due to the rather high soil organic C (SOC) contents of 2.2 and 2.8% with Koc values in the same range as those of the biochars. However, OBC and RBC additions can substantially increase adsorption of Phe in soils poor in SOC.


1958 ◽  
Vol 38 (2) ◽  
pp. 85-93 ◽  
Author(s):  
R. L. Halstead ◽  
A. J. MacLean ◽  
K. F. Nielsen

When carbonates of magnesium or calcium were added to surface samples of four acid soils to establish a range in exchangeable Ca:Mg ratios, magnesium carbonate reduced exchangeable calcium and, with one exception, calcium carbonate reduced exchangeable magnesium. Corresponding reductions of water-soluble magnesium and calcium occurred in two of the soils. For a given amount of the cation in exchangeable form, there was more magnesium than calcium in water-soluble form. The carbonate treatments had no effect on exchangeable potassium but usually reduced water-soluble potassium. The exchangeable Ca:Mg ratios in the different soils varied from 0.6:1.0 to 1.5:1.0 where magnesium carbonate was applied, and from 4.1:1.0 to 13.5:1.0 where calcium carbonate was used.Yields of alfalfa grown in the soils increased with addition of carbonates. The width of the Ca:Mg ratio in the treated samples had no significant effect on yield except in one soil where the pH was raised to slightly above the neutral point. Magnesium carbonate reduced calcium in the plants more than calcium carbonate reduced magnesium. With addition of potassium, the percentage reduction of plant magnesium was greater than that of calcium. Values for sum of cations in the plants were reduced by the magnesium carbonate treatment and usually by addition of potassium. The carbonate of calcium tended to be slightly more effective than that of magnesium in increasing the phosphorus content of the plants.From the standpoint of alfalfa yield, it is suggested that a magnesian limestone may be expected to be a satisfactory corrective of acidity, even though the resulting Ca:Mg ratio in the soil may be relatively low.


2018 ◽  
Author(s):  
Eduardo Moreno Jiménez ◽  
Sara Aceña-Heras ◽  
Vladimir Fristak ◽  
Stefanie Heinze ◽  
Bernd Marschner

The contamination of soils and waters with organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs), affect a large number of sites worldwide that need remediation. In this context soils amendments can be used to immobilise PAHs while maintaining soil functioning, with biochar being a promising amendment. In this experiment phenantrene (Phe) was used as a frequent PAH contaminating soils and we studied the effect of three biochars at 1% applications to three different substrates, two agricultural topsoils and pure sand. We evaluated the changes in soil properties, sorption-desorption of Phe, and mineralisation of Phe in all treatments. Phe in pure sand was effectively sorbed to olive pruning (OBC) and rice husk (RBC) biochars, but pine biochar (PBC) was not as effective. In the soils, OBC and RBC only increased sorption of Phe in the silty soil. Desorption was affected by biochar application, RBC and OBC decreased water soluble Phe independently of the soil, which may be useful in preventing leaching of Phe into natural waters. Contrastingly, OBC and RBC slightly decreased the mineralisation of Phe in the soils, thus indicating lower bioavailability of the contaminant. Overall, biochar effects in the two tested soils were low, most likely due to the rather high soil organic C (SOC) contents of 2.2 and 2.8% with Koc values in the same range as those of the biochars. However, OBC and RBC additions can substantially increase adsorption of Phe in soils poor in SOC.


Author(s):  
J. G. Robertson ◽  
D. F. Parsons

The extraction of lipids from tissues during fixation and embedding for electron microscopy is widely recognized as a source of possible artifact, especially at the membrane level of cell organization. Lipid extraction is also a major disadvantage in electron microscope autoradiography of radioactive lipids, as in studies of the uptake of radioactive fatty acids by intestinal slices. Retention of lipids by fixation with osmium tetroxide is generally limited to glycolipids, phospholipids and highly unsaturated neutral lipids. Saturated neutral lipids and sterols tend to be easily extracted by organic dehydrating reagents prior to embedding. Retention of the more saturated lipids in embedded tissue might be achieved by developing new cross-linking reagents, by the use of highly water soluble embedding materials or by working at very low temperatures.


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