Column study of the leaching and degradation of anionic surfactants in oil-polluted soil; 87–97

2007 ◽  
Vol 56 (2) ◽  
pp. 87
Author(s):  
J Budashova ◽  
A Selberg ◽  
T Tenno
2019 ◽  
pp. 405-412
Author(s):  
Aare Selberg ◽  
Jana Budashova ◽  
Kalev Uiga ◽  
Toomas Tenno

Surfactants are applied as emulsifiers or solubilizers by treatment of polluted soil. Theproblem of secondary pollution has arisen as result of the surfactant-enhanced remediation ofa polluted soil contaminated with hydrophobic organic compounds. Several studies haveshown that the surfactants are biodegradable in aerobic conditions and the biodegradabilitydepended on the chemical properties and concentration of surfactant. A study of the leachingof surfactants from the soil is important, as it is difficult to identify the reason for thereduction of concentration of pollutants in the soil: is it degradation or leaching? Theexperiments were carried out with a fine sandy soil in column tests and CaCO3 was added toincrease soil pH. The soil was treated twice with the bioremediation agent SR-100. The soilpH, the concentrations of anionic surfactant and petroleum hydrocarbons at the differentdepths of soil were determined. The microbial activity of soil fractions was evaluated byrespirometer. The concentration of surfactants was determined colorimetrically as MethyleneBlue active substances (MBAS). The concentration of anionic surfactants decreased in theupper layer of the columns, but it increased in the lower layers. It indicated the leaching ofthe anionic surfactants from soil during experiments of 60 days. The amounts of residualsurfactants were lower in the samples of polluted soil in comparison with unpolluted soil. Thesamples of lower soil fractions had higher microbial activity in comparison with upperfractions. Soil pH was measured as pHH20, pHKcl and pHcac12 instead of the pH of soilsolution, because soil was too dry. The pH of fine sandy soil was 5.8 and during theexperiment the value of pH increased in the lower layer of soil till pHH20 = 7.5.


Author(s):  
E. Naranjo

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.


2019 ◽  
Vol 18 (6) ◽  
pp. 1297-1309
Author(s):  
Antonis A. Zorpas ◽  
Maria K. Doula ◽  
Vassilis J. Inglezakis ◽  
Jose Pedreno Navvaro ◽  
Dimitrios J. Bilalis

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.


2020 ◽  
Vol 51 (6) ◽  
pp. 528-540
Author(s):  
I. V. Lyanguzova ◽  
M. S. Bondarenko ◽  
A. I. Belyaeva ◽  
M. N. Kataeva ◽  
V. Sh. Barkan ◽  
...  

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