Ultrasound Assisted Removal of Unstable Form of Cu and Ni from Contaminated Soil

2014 ◽  
Vol 522-524 ◽  
pp. 678-681
Author(s):  
Chun Lei Zhang ◽  
A. K. Agadzi ◽  
Xiao Tong Fei ◽  
Ting Li

Heavy metals exist in different forms in polluted soils however only the unstable form is bioavailable and potentially threatening to the environment. This study adopted the ultrasound technique as a tool to transform the unstable heavy metal forms into soluble forms and remove them. Acoustic cavitation coupled with mechanical stirring was used to facilitate the removal of Cu and Ni from a polluted soil. Effect of sonication treating time, sonication power and slurry concentration factors on the removal efficiency (RE) were studied. Test results show that the RE increase with sonication treating time, the best RE for Cu and Ni are 40-50 minutes and 30-40 minutes respectively. Increasing the sonication power can improve the removal of Cu but particularly for Ni, the optimal sonication power is 400W. High concentration slurry is better for Cu removal but for Ni, a more dilute slurry is more effective.

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1608
Author(s):  
Aslihan Esringü ◽  
Metin Turan ◽  
Asli Cangönül

Heavy metal pollution is among the important environmental problems in the world. Many techniques have already been used to remove the heavy metals such as lead (Pb) and cadmium (Cd). Among them, the phytoremediation method is an environmentally friendly and green technology. This study was carried out to determine the efficiency of fulvic acid (FA) application in removing Pb and Cd from polluted soil using Tagetes eracta L. and Zinnia elegans Jacq. ornamental plants. The results indicated that, FA application, number of flower per plants, and plant fresh weight of Tagetes eracta plants and Zinnia elegans plants increased 187.5%, 104.5% and 155.5%, 57.7%, respectively with application of 7000 mg L−1 FA at 100 mg kg−1 Pb pollution condition, whereas 42.85%, 16.5%, and 44.4–36.1% with application of 7000 mg L−1 FA at 30 mg kg±1 Cd pollution condition, respectively. With the FA application in the Zinnia elegans plant, the root part has accumulated 51.53% more Pb than the shoot part. For Cd, the shoot part accumulated 35.33% more Cd than the root. The effect of FA application on superoxide dismutase (SOD), peroxidase (POD) and, catalase (CAT) of the Tagetes eracta were decreased as 32.7%, 33.1%, and 35.1% for Pb, 21.2%, 25.1%, and 26,1%, for Cd, and 15.1%, 22.7%, and 37.7% for Pb, and 7.55%, 18.0%, and 18.8% for Cd were in Zinnia elegans respectively. In conclusion, Tagetes eracta and Zinnia elegans can not be recommended for remediation of Pb and Cd polluted area, but FA can be recommended for Pb and Cd stabilization in polluted soil.


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1057
Author(s):  
Ehab Azab ◽  
Ahmad K. Hegazy

Heavy metal-contaminated soil constitutes many environmental concerns. The toxic nature of heavy metals poses serious threats to human health and the ecosystem. Decontamination of the polluted soil by phytoremediation is of fundamental importance. Vegetation is an appealing and cost-effective green technology for the large-scale phytoremediation of polluted soils. In this paper, a greenhouse experiment was carried out to test the potential of Rhazya stricta as a heavy metal phytoremediator in polluted soil. Plants were grown for three months in pots filled with soils treated with the heavy metals Cd, Pb, Cu, and Zn at rates of 10, 50, and 100 mg/kg. The bioaccumulation factor (BCF) and translocation factor (TF) were calculated to detect the ability of R. stricta to accumulate and transfer heavy metals from soil to plant organs. The results showed that under increasing levels of soil pollution, the bioconcentration of Cd and Zn heavy metals showed the highest values in plant roots followed by leaves, whereas in the case of Pb and Cu, roots showed the highest values followed by stems. Heavy metals accumulation was higher in roots than in stems and leaves. The BCF of Zn reached the highest values in roots and stems for 10 mg/kg soil treatment, followed by the BCFs of Cd, Cu, and Pb. The TF for the different heavy metal pollutants’ concentrations was less than unity, suggesting that the plants remediate pollutants by phytostabilization. The TF values ranged from higher to lower were in the order Zn > Cu > Cd > Pb. The rapid growth of R. stricta and its tolerance of heavy metals, as well as its ability to absorb and accumulate metals within the plant, recommends its use in the phytoremediation of slightly polluted soils in arid lands by limiting the heavy metals transport.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1394
Author(s):  
Paloma Campos ◽  
Heike Knicker ◽  
Rafael López ◽  
José María De la Rosa

Soil pollution by trace elements is a huge problem around the globe. In addition, heavy metal immobilization and primary productivity are two soil ecosystem services of contemporary importance to society. The goal of this study was to evaluate the effects of using olive pit and rice husk biochars as soil amendments for the immobilization of trace elements and on plant development growing in heavy metals-polluted soils under greenhouse conditions. The application of high doses (5% and 10%) of biochar significantly increased pH, water holding capacity and total C content of the soils. Dehydrogenase activity in the moderately acidic soil was greater than in the acidic soil due to the high concentration of metals and high acidity of the latter. The application of biochar reduced the β–glucosidase activity. Furthermore, the concentrations of CaCl2-extractable heavy metals significantly decreased in biochar amended pots, indicating metal immobilization, which was consistent with the increase in soil pH. Distribution of trace elements in the different fractions was modified after 65 days of incubation, independently of the treatment. The Cu and Zn contents in the oxidizable fraction were reduced with incubation, whereas Cd and Zn in the residual fraction increased. The reduction of bioavailable concentrations and increments in the residual or more stable fractions indicated less risk for the organisms in the environment. All biochars addition significantly increased the root-to-shoot ratio compared to the control soil. Particularly, 10% of amendment increased this ratio in the greatest extent. The application of 10% w/w of rice husk biochar produced at 500 °C was the most effective in restoring soil functionality and reducing the availability of heavy metals in the polluted soils.


Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 


2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.


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 ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 649
Author(s):  
Estefanía Noriega-Fernández ◽  
Izumi Sone ◽  
Leire Astráin-Redín ◽  
Leena Prabhu ◽  
Morten Sivertsvik ◽  
...  

The aim of this work was to evaluate the potential of ultrasound (US), alone or in combination with mild heating and/or EDTA towards reduction of As, Cd, I, and Hg content of Laminaria hyperborea. Concentrations of As, Cd, I, and Hg of 56.29, 0.596, 7340, and <0.01 mg kg−1 of dry weight, respectively, were found in L. hyperborea blades. Treatment with US at 50 °C increased approx. 2-fold the amount of As released, although did not affect significantly the content of Cd or I, as compared to control (no US) samples. Reducing the temperature to 8 °C significantly decreased the effect of US, but heating at 80 °C did not cause a significant effect as compared to treatments at 50 °C. On the other hand, treatment with 0.1 N EDTA at 50 °C enhanced the percentage of Cd released by approximately 7-fold, regardless of sonication. In the present work, the combination of US and EDTA at 50 °C for 5 min led to a significant reduction of the As (32%), Cd (52%) and I (31%) content in L. hyperborea, thus improving the product’s safety for consumers.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Azizul Moqsud

AbstractIn this research, bioremediation of tsunami-affected polluted soil has been conducted by using collective microorganisms and recycled waste glass. The Tohoku earthquake, which was a mega earthquake in Japan triggered a huge tsunami on March 11th, 2011 that caused immeasurable damage to the geo-environmental conditions by polluting the soil with heavy metals and excessive salt content. Traditional methods to clean this polluted soil was not possible due to the excess cost and efforts. Laboratory experiments were conducted to examine the capability of bioremediation of saline soil by using recycled waste glass. Different collective microorganisms which were incubated inside the laboratory were used. The electrical conductivity (EC) was measured at different specified depths. It was noticed that the electrical conductivity decreased with the assist of the microbial metabolisms significantly. Collective microorganisms (CM2) were the highly capable to reduce salinity (up to 75%) while using recycled waste glass as their habitat.


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