scholarly journals POSSIBILITIES OF PURIFICATION OF HEAVY METALS CONTAMINATION IN SOILS

2019 ◽  
Vol 1 (11(41)) ◽  
pp. 7-9
Author(s):  
N. A. Kavtaradze ◽  
K. N. Kochiashvili ◽  
M. A. Stephanishvili ◽  
T. A. Dgebuadze ◽  
M. Z. Japaridze

Methods of neutralisation of different types of soils contaminated with heavy metals are studied. Certain strains of microorganisms have been selected, local microflora has been studied and identified at the genus level in laboratory conditions. Considering the conducted works, development of modified forms of humic acids, stimulation of local microorganisms and creation of geochemical barriers using local natural raw materials is recomended. Obtained results makes possible to develop comprehensive and rational model by means of inovative technologies for effective purification of soils contaminated with heavy metals.

2020 ◽  
Vol 18 (1) ◽  
pp. 58-68 ◽  
Author(s):  
Minru Liu ◽  
Zhihua Tang ◽  
Zhenrong Lin ◽  
Huafang Guo ◽  
Zhen Yu ◽  
...  

AbstractTo investigate the characteristics of humic acids (HAs) and the combined effects of HAs on heavy metals, three HAs derived from kitchen waste compost (KW), pig manure compost (PM), and green waste compost (GW) were exposed to Cd(II) and Zn(II). The elemental contents and functional groups of HAs were different due to different raw materials. Fulvic-, humic-like content C1, humic-like content C4, and two protein-like contents C2 and C3 were identified in three HAs by EEM-PARAFAC analysis. The effects of HAs on heavy metals were associated with the metal species and HA source. Our results reveal that titrating Cd(II) caused stronger fluorescence quenching compared to titrating Zn(II) for all HAs. C1 and C4 of KW-HAs and PM-HAs showed fluorescence quenching after Cd(II) was added, whereas negligible fluorescence quenching was found when Zn(II) was added. In addition, C1 and C4 in the GW-HAs did not show obvious fluorescence quenching regardless of whether Cd(II) or Zn(II) was added. C3 in all HAs caused significant fluorescence quenching, suggesting that C3 plays an important role affecting the mobility of heavy metals. Consequently, these results suggest that HAs from KW and PM have greater potential for Cd-contaminated soil remediation than those from GW.


Author(s):  
R. Z. Uridia ◽  
N. A. Kavtaradze ◽  
K. N. Kochiashvili ◽  
M. A. Stephanishvili ◽  
I. I. Mikadze ◽  
...  

Waste generated due to the growth of the modern industry is undergoing natural disposal in the environment for a long period of time. A special danger is caused by heavy metals that do not undergo biodegradation. Known purification methods of soils are not always effective and profitable. Correct selection of soil remediation methods contaminated with heavy metals ensures effective cleaning and restoration of soils. For this purpose, selecting representatives of various taxonomic groups of microorganisms binding heavy metals in the soil is carrying out. A complex method of purification of soils contaminated with have metals is being developed. Modified forms of humic acids were developed, geochemical barriers using local clays were created. Works to biostimulate local microorganisms required for bioremediation of soils contaminated with heavy metals are conducted. Remediation and increasing the fertility of soils contaminated with heavy metals are necessary for the prevention of further penetration of these metals into agricultural crops.


2007 ◽  
Vol 32 (7) ◽  
pp. 5405-5512
Author(s):  
M. Abou-Raya ◽  
M. Shalaby ◽  
A. Kassem ◽  
Amalika El-Dahshan ◽  
Faten Ibrahim

Author(s):  
O. M. Mamenko ◽  
S. V. Portiannik

Around the industrial cities, the difficult environmental situation is due to the release of pollutants in the atmosphere that contain heavy metals, especially those that are dangerous to the environment, such as cadmium and lead. The increase in the accumulation of pollutant in soils of agricultural land also leads to the use of agrochemicals – pesticides and mineral fertilizers. Under such environmental conditions, it is necessary not only to grow crop production, but also to produce livestock products – milk. The production of environmentally safe, high-quality and competitive on the milk market requires the use of proven technological feeding and animal feeding methods. The selection of the optimal type of feeding of cows reduces the transition of heavy metals into dairy raw materials. In the experiment, it was found that the siln-root-type type of feeding had the smallest transition of Cd and Pb from feed rations into dairy raw materials, the transition factor of cadmium – 0.24, lead – 0.25. The most intense was the migration of Pb from the ration to milk from cows of the first control group with the silo-hinga-co-central type of feeding: the transition factor was 0.39 and Cd was 0.34. A similar situation was observed in cows of the first control groups with males and females feeding type, where the transition factor was 0.36 Cd and 0.34 Pb. The total supply of heavy metals with the diet for different types of feeding practically did not differ. The balancing of dietary rations with the specially developed mineral-vitamin premix “MP-A” contributed to the reduction of the transition of heavy metals Cd, Pb, Cu and Zn into milk, while the highest quality milk was obtained from cows with a haylage type of feeding. As a result of the experiment, it was possible to achieve a positive effect and reduce the content of heavy metals in milk of cows in all farms with different types of feeding animals for optimum quality and safety of milk, which met the requirements of the state standard, which convinces the transition factor, which was in the cows of the second experimental group on Cd 0,09 in animals with a sows-root-type type of feeding; 0.10 – silo-haylage; 0.12 – silage-hay type and 0.15 with silo-haylage-concentrate type, respectively; Pb – 0.01 in cows with a hill-and-hay type of feeding; 0.07 – silo-haylage-concentrate; 0.08 – silo-root crop and 0.09 with silo-hay type respectively; Cu – 0.01 in cows with silo-haylage and silo-root-crop type of feeding; 0.02 with silo-haylage-concentrate and silo-hay type respectively; Zn – 0.05 in animals with males and haylings type of feeding; 0.06 – silo-haylage-concentrate; 0.08 – silo-root crop and 0.010 with silo-hay type, respectively. In the third experimental group of cows, the average transition factor of heavy metals from milk to Cd, Pb, Cu and Zn was 0.04. The use of premix and bio-preparation has reduced the transition of heavy metals from milk to an average of 1.5–4.3 times. Productivity of animals was on average in cows of the second and third experimental groups of 17–22 kg per day compared with the control group – 14 kg. The content of Cd in the milk of dairy cows with a hay-concentrate-feeding type was 0.053 mg/kg in the first control group, in the second experimental group, where the mineral-vitamin premix “MP-A” was additionally fed to 0.024, and in the third, where Subcutaneous injection of biologically active drug “BP-9” was used up to 0.014 mg/kg; Pb from 1.794 mg/kg – to 0.331 and 0.032 mg/kg respectively; Cu from 2.63 mg/kg to 0.34 and 0.35 mg/kg respectively; Zn from 8.74 mg/kg to 4.97 and 3.87 mg/kg, respectively. Feeding cows to antioxidant premix allows approximately 2–2.5 times to reduce the transition from diet to dairy raw materials that are hazardous to animal health and the quality of milk toxicants for any type of feeding. Future studies are aimed at studying the effects of different types of feeding, taking into account the balancing of diets with a special premix for the production of high-quality, environmentally safe milk.


2016 ◽  
Vol 15 (3) ◽  
pp. 579-587 ◽  
Author(s):  
Maria-Ema Faciu ◽  
Francois Xavier Nshimiyimana ◽  
Souad El Blidi ◽  
Abdellah El Abidi ◽  
Abdelmajid Soulaymani ◽  
...  

Author(s):  
Diana Demiyah Mohd Hamdan ◽  
Mohd Khalizan Sabullah ◽  
Jovelyn Seludin ◽  
Amirah Syuhada Mohd Azman ◽  
Mohd Hamdan Adnan

2021 ◽  
Vol 9 (7) ◽  
pp. 1417
Author(s):  
Xuejun Wang ◽  
Si Shen ◽  
Hao Wu ◽  
Haixia Wang ◽  
Lvjing Wang ◽  
...  

Dipropyl phthalate (DPrP) coexists with cadmium as cocontaminants in environmental media. A coculture system including the DPrP-degrading bacterium Glutamicibacter nicotianae ZM05 and the nondegrading bacterium Acinetobacter tandoii ZM06 was artificially established to degrade DPrP under Cd(II) stress. Strain ZM06 relieved the pressure of cadmium on strain ZM05 and accelerated DPrP degradation in the following three ways: first, strain ZM06 adsorbed Cd(II) on the cell surface (as observed by scanning electron microscopy) to decrease the concentration of Cd(II) in the coculture system; second, the downstream metabolites of ZM05 were utilized by strain ZM06 to reduce metabolite inhibition; and third, strain ZM06 supplied amino acids and fatty acids to strain ZM05 to relieve stress during DPrP degradation, which was demonstrated by comparative transcriptomic analysis. This study provides an elementary understanding of how microbial consortia improve the degradation efficiency of organic pollutants under heavy metals contamination.


2021 ◽  
pp. 002199832110316
Author(s):  
Nuno Gama ◽  
B Godinho ◽  
Ana Barros-Timmons ◽  
Artur Ferreira

In this study polyurethane (PU) residues were mixed with residues of textile fibers (cotton, wool and synthetic fibers up to 70 wt/wt) to produce 100% recycled composites. In addition, the effect of the type of fiber on the performance of the ensuing composites was evaluated. The presence of fibers showed similar effect on the density, reducing the density in the 5.5-9.0% range. In a similar manner, the addition of fillers decreased their thermal conductivity. The 70 wt/wt wool composite presented 38.1% lower thermal conductivity when compared to the neat matrix, a reduction that was similar for the other type of fibers. Moreover, the presence of fillers yields stiffer materials, especially in the case of the Wool based composites, which with 70 wt/wt of filler content increased the tensile modulus of the ensuing material 3.4 times. This was attributed to the aspect ratio and stiffness of this type of fiber. Finally, the high-water absorption and lower thermal stability observed, especially in the case of the natural fibers, was associated with the hydrophilic nature of fibers and porosity of composites. Overall, the results suggest that these textile-based composites are suitable for construction and automotive applications, with the advantage of being produced from 100% recycled raw-materials, without compromised performance.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.


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