scholarly journals Mercury uptake by Paspalum distichum L. in relation to the mercury distribution pattern in rhizosphere soil

Author(s):  
Su Xu ◽  
Ping Gong ◽  
Wen Ding ◽  
Shengchun Wu ◽  
Xinwei Yu ◽  
...  

Abstract Paspalum distichum L. was tested to evaluate their phytoremediation capacity for Hg contaminated soil through analyzing the dissipation of Hg in soil through a greenhouse study by using self-made rhizos box. Original soil samples were collected at Hg mining site with serious Hg contamination and a control site, respectively. Planting of P. distichum. L last for 60 days. Soil and plant samples were collected from four periods (0 d, 20 d, 40 d and 60 d) and soil samples were collected from five different rhizosphere distance in horizontal direction (0–2 cm, 2-4cm, 4-6cm, 6-8cm,8-10cm). The results showed that the presence of P. distichum. L significantly accelerated the Hg dissipation in soil compared with control. Hg concentration in the rhizospheric soil was affected by the plant growth period and the distance to the plant roots. The closer of soil to the root of P. distichum. L, the lower mercury concentration in soil. During the 60-day growing period, the concentrations of total Hg (THg) and methylmercury (MeHg) reduced by 45% and 64%, respectively, in the rhizosphere (0-2cm) of Hg contaminated soil. However, MeHg concentration was increased near the roots (0–4 cm) during the initial growing period (0–20 d), which may be attributed to the influence of root exudates. Root is the major part for Hg accumulation in P. distichum. L. The low ratio between Hg concentrations in underground and aboveground tissues indicated that it seemed difficult for Hg translocation from root to shoot. The highest THg (9.71 ± 3.09 µg·g− 1) and MeHg (26.97 ± 0.98 ng·g− 1) value in root of P. distichum. L were observed at the 20th day when P. distichum. L grown in Hg contaminated soil. The results of chemical fractions analyses showed that elemental Hg and residual Hg were the two major speciations followed by organic bound Hg in the Hg contaminated soil, which indicated the high bioavailability and ecological potential risk of Hg in Hg contaminated soil.

Author(s):  
Beheshteh Haghparast-kenari ◽  
Tooran Nayeri ◽  
Shahabeddin Sarvi ◽  
Mohammad Taghi Rahimi ◽  
Ehsan Ahmadpour ◽  
...  

Background: Soil-transmitted parasites (STPs) are significant intestinal parasites that infect humans and animals and impose considerable burdens on human society and animal husbandry industries. Therefore, the present study aimed to determine the prevalence of parasitic elements of soil samples collected from the north of Iran. Methods: A total of 256 soil samples were collected from public parks, public places, vegetable gardens, sand heaps, and shadow areas near houses in the north of Iran and examined using the sucrose flotation method. Results: Out of 256 examined samples, 131 (51.2%) ones showed parasitic contamination including larvae (43%), oocysts (14.1%), and different eggs (6.6%). According to the results, the most and least common parasites observed in the samples were larvae (43%), as well as Toxascaris leonina, and Trichuris trichiura (0.4%), respectively. Moreover, the most and least contaminated locations were sand heaps (62.5%) and shadow areas near houses (45.6%), respectively. Regarding cities, Behshahr (68.3%) and Sari (67.5%) had the highest contaminated soil samples, whereas Chalus (37.5%) showed the lowest contamination. On the other hand, rural samples showed more contamination, compared to urban areas (P< 0.05). Conclusion: The findings of the present study indicate that the overall prevalence of STPs in examined areas and highly contaminated soil samples can be considered as a potential source of human contamination particularly tourists with STPs.


2018 ◽  
Vol 9 (1) ◽  
pp. 79-84
Author(s):  
Vaishali V. Shahare ◽  
Rajni Grover ◽  
Suman Meena

Background: The persistent dioxins/furans has caused a worldwide concern as they influence the human health. Recent research indicates that nonmaterial may prove effective in the degradation of Dioxins/furans. The nanomaterials are very reactive owing to their large surface area to volume ratio and large number of reactive sites. However, nanotechnology applications face both the challenges and the opportunities to influence the area of environmental protection. Objective: i) To study the impact of oil mediated UV-irradiations on the removal of 2,3,7,8-TCDD, 2,3,7,8-TCDF, OCDD and OCDF in simulated soil samples. ii) To compare the conventional treatment methods with the modern available nanotechniques for the removal of selected Dioxins/furans from soil samples. Methods: The present work has investigated an opportunity of the degradation of tetra and octachlorinated dioxins and furans by using oil mediated UV radiations with subsequent extraction of respective dioxins/furans from soils. The results have been compared with the available nanotechniques. Results: The dioxin congeners in the simulated soil sample showed decrease in concentration with the increase in the exposure time and intensity of UV radiations. The dechlorination of PCDD/Fs using palladized iron has been found to be effective. Conclusion: Both the conventional methods and nanotechnology have a dramatic impact on the removal of Dioxins/furans in contaminated soil. However, the nanotechniques are comparatively costlier and despite the relatively high rates of PCDDs dechlorination by Pd/nFe, small fraction of the dioxins are recalcitrant to degradation over considerable exposure times.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ehizonomhen S. Okonofua ◽  
Kayode H. Lasisi ◽  
Eguakhide Atikpo

AbstractLand farming technique was used to treat hydrocarbon contaminated soil collected from a crude oil spill sites in Edo State, Nigeria. Calibrated standard auger was used to collect soil samples from the site at depth below 30 cm. The samples were characterized and classified. Cow dung and NPK fertilizer were added as additives to complement the nutriments of the soil samples before total petroleum hydrocarbon (TPH) quantification and remediation procedures. Factorial design was applied to vary the input parameters such as pH, mass of substrate, moisture content and turning times of land farming so to ascertain the optimal conditions for the procedure. The result revealed that the in-situ TPH value was 5000 mg kg− 1 on the average and after 90 d of treatment, TPH reduced to 646 mg kg− 1. The turning rate, pH, moisture content and mass of substrate hade 83, 4.36, 0.48 and 0.046% contribution, respectively, for the degradation process using land farming treatment. Numerical optimization techniques applied in the optimum point for land farming input parameters to achieve predicted maximum removal of 99% were evaluated as pH, mass of substrate, moisture content and turning rate to be 6.01, 1 kg, 10% and 5 times in a week, respectively. TPH removed at this optimum point was 98% reducing from 5000 to 636 mg kg− 1. The high coefficient of determination (r2 = 0.9865) as observed in the closeness of predicted and experimental values reflects the reliability of the model and hence, land farming practice with close attention on turning rate as revealed by this study, is recommended for TPH contaminated soil remediation.


2010 ◽  
Vol 34 (3) ◽  
pp. 985-992 ◽  
Author(s):  
Roseli Freire Melo ◽  
Luiz Eduardo Dias ◽  
Jaime Wilson Vargas de Mello ◽  
Juraci Alves Oliveira

Arsenic has been considered the most poisonous inorganic soil pollutant to living creatures. For this reason, the interest in phytoremediation species has been increasing in the last years. Particularly for the State of Minas Gerais, where areas of former mining activities are prone to the occurrence of acid drainage, the demand is great for suitable species to be used in the revegetation and "cleaning" of As-polluted areas. This study was carried out to evaluate the potential of seedlings of Eucalyptus grandis (Hill) Maiden and E. cloeziana F. Muell, for phytoremediation of As-polluted soils. Soil samples were incubated for a period of 15 days with different As (Na2HAsO4) doses (0, 50, 100, 200, and 400 mg dm-3). After 30 days of exposure the basal leaves of E. cloeziana plants exhibited purple spots with interveinal chlorosis, followed by necrosis and death of the apical bud at the 400 mg dm-3 dose. Increasing As doses in the soil reduced root and shoot dry matter, plant height and diameter in both species, although the reduction was more pronounced in E. cloeziana plants. In both species, As concentrations were highest in the root system; the highest root concentration was found in E. cloeziana plants (305.7 mg kg-1) resulting from a dose of 400 mg dm-3. The highest As accumulation was observed in E. grandis plants, which was confirmed as a species with potential for As phytoextraction, tending to accumulate As in the root system and stem.


2021 ◽  
Vol 86 (1) ◽  
Author(s):  
G. Zh. Abdieva ◽  
P. S. Ualieva ◽  
А. М. Мalik ◽  
N. S. Akimbekov ◽  
А. N. Eshmukhanbet ◽  
...  

2018 ◽  
Vol 15 (35) ◽  
pp. 158-168
Author(s):  
Firas M. Radhi

In the present research, the chemical washing method has been selected using three chelating agents: citric acid, acetic acid and Ethylene Diamine Tetraacetic Acid (EDTA) to remove 137Cs from two different contaminated soil samples were classified as fine and coarse grained. The factors that affecting removal efficiency such as type of soil, mixing ratio and molarity have been investigated. The results revealed that no correlation relation was found between removal efficiency and the studied factors. The results also showed that conventional chemical washing method was not effective in removing 137Cs and that there are further studies still need to achieve this objective.


2021 ◽  
Vol 2 (1) ◽  
pp. 84-95
Author(s):  
David Okechukwu Okeke ◽  
◽  
Jonathan Chinenye Ifemeje ◽  

The level of heavy metals (Fe, Cu, As, Pb, Cd, Mg, Ca, Hg, Ni, Cr, Zn, Ag, Co, Mo, Se and Al) in soils and food crops (okra, cassava and rice) cultivated within selected mining sites in Ebonyi State, Nigeria were determined using FS240AA Atomic Absorption Spectrophotometer (AAS) according to the method of American Public Health Association (APHA). Soil samples were collected from Enyigba mining site, Ikwo mining site, AmeriAmekamining site, Izza mining site, MkpumeAkwatakwa mining site and MpumeAkwaokuku mining site while the food crop samples (okra, cassava and rice) were collected from the farmlands within the mining sites. Control samples were collected 500m away from the mining destinations were there was no evidence of mining activities on the soils. A total of sixty sub-samples and six control soil samples were collected for this study. Generally, the values of all the heavy metals analyzed for soil and food crop samples were higher than the values recommended by the World Health Organization (WHO), and those from the control site suggesting possible mobility of the metals from mining sites to farmlands through leaching and runoffs. The findings in this study also revealed that the food crops contain heavy metals exceeding the maximum permissible concentration, and could be detrimental to human health when they are consumed.


Author(s):  
M. N. Okeke ◽  
Paul Chukwuka Eze ◽  
C. N. Eze

<strong>Aims:</strong> The purpose of this project is to find the concentration of heavy metals (Cu, Zn, Pb, As, Cr, Ni, Cd, Fe and Mn) in the top soil and the plant around the waste dumpsite from Enugu municipal solid waste disposal sites. <strong>Methodology and results: </strong>This was done through collection of soil samples from four designated public municipal solid waste dump sites (Ngwo Umueze, Presidential, New-market and Emene) in Enugu metropolis. The soil samples were collected at 10 metres intervals away from the centre location point of each dump site at constant depth (0 - 15 cm were mixed together and sample picked from it). The samples collection design are as follows: centre (0m) of the dump sites, 10 metres, 20 metres, 30 metres and the control sample which measured 65 metres away from the centre of dumpsites at the same depth. Plant samples were taken just at the centre (0m) and control measures which is at 65 meters distance away from each dump sites. The Goat grasses harvested were taken to the lab to check and analyse its heavy metals intake from the soil. These samples were analysed using atomic absorption spectrophotometer (AA320N) model. On the average, high concentrations of Zn, Fe, Mn, Cu, and Pb were found in the soil samples collected at the centre of the dump sites as 141.70, 121.5, 75.53, 70.33 and 64.53mg/kg respectively. The lower concentrations were obtained in the soil samples taken at the control site which 65 metres distance away from the centre of the four dump sites as 12.00, 81.55, 8.70, 9.56 and 6.51mg/kg for Zn, Fe, Mn, Cu, and Pb respectively. In the plant sample, concentration of Fe (98.00 mg/kg) was found to be the highest in the root at New market dumpsites, while Nil concentration of as (Nil mg/kg) was the least value at Emene from the control distance. <strong>Conclusion, significance and impact study:</strong> SPSS statistical package was used to find out the significant differences between the treatments mean (heavy metals). The result shows that the heavy metals analyses were within the acceptable or permissible limit by WHO/FAO.


Sign in / Sign up

Export Citation Format

Share Document