scholarly journals Heavy Metal Content and Physico-Chemical Analyses of Soils under the Litter of some Medicinal Taxa in the Luki Biosphere Reserve, Democratic Republic of the Congo

Author(s):  
Florent Biduaya Mukeba ◽  
Myriam Mukadi Ngondo ◽  
Nazaire Kabemba Kadima ◽  
Prince Bofati Ilonga ◽  
Patrick Kayembe Bibasuya ◽  
...  

Aim: The aim of this study was to compare the texture, mineral element and heavy metal content of the soil under the litter of different selected species in relation to the plan of their pedogenesis. Methods: The granulometric analysis of the various samples based on laser diffraction, measurements of Total Nitrogen and Total Organic Carbon were performed using the Elemental Analyzer, the Organic Matter content is estimated by the loss of ignition method using a Salvis furnace, In order to estimate the CaCO3 content. The same samples were heated in the oven at 1000°C for 60 minutes and reweighed. The carbonate content is estimated by the loss in mass during this second firing, multiplied by 2.274 which is the molecular weight ratio between CaCO3 and CO2. The heavy metal and mineral composition was evaluated by ICP-AES and AAS. Results: The granulometric analyses show a sandy texture, according to the FAO classification. The organic matter content thus observed in the soils under the litter of these four species did not show any significant difference. The concentration of major mineral elements recorded in soils under the litter of Blighia welwitchii, Oncoba welwitschii, Zanthoxylum gilletii and Harungana madagascariensis did not show any significant difference. However, potassium, phosphorus, and magnesium have a high concentration compared to calcium and sodium. This study showed that the levels of cadmium, lead, arsenic and aluminum in the various samples of litter soils of all plant species including nickel for B. welwitschii are above the standards set by the Canadian Council of Ministers of the Environment for soil quality. Pollution factors for aluminum are the highest. This indicates that aluminum is the most polluting metal. The low pollution factors for lead and nickel are due to the low fixation of these metals by soils. Conclusions: Our study took place in the Luki Biosphere reserve and showed that the different soils under litter are polluted by very toxic and persistent heavy metals such as cadmium, lead, aluminum, arsenic and nickel. This study has revealed new aspects of heavy metal pollution. This pollution represents a serious threat to the environment in general and to humans in particular through the food chain.

2020 ◽  
Vol 4 (1) ◽  
pp. 33-39
Author(s):  
M. M. Rahman ◽  
M.S.H. Bhuiyan ◽  
M.A. Rouf ◽  
R.R. Sarker ◽  
M. H. Rashid

AbstractThere are more than 522 towns and cities in Bangladesh, which generate thousands of tons of solid waste known as Municipal Solid Waste. Low collection coverage and disposal facilities are responsible for unsatisfactory waste management. The composting technology is a good alternative method for managing MSW. The present study was conducted to assess the quality of the MSW compost produced from the solid wastes of Mymensingh Pourashava. For quality assessment physical, chemical and biological properties of prepared compost namelye bulk density, porosity, water-holding capacity, moisture content, pH, organic matter content, C:N ratio, NPKS content, buffering capacity, soluble salts content, heavy metal content and the presence of harmful organisms in the MSW compost were studied. The results indicated that the MSW compost was matured and stable having pH 7.3 and buffering capacity of the MSW compost were good but the organic matter content and C : N (14.5) ratio were low. The N, P, K and S content of the MSW compost were 0.9, 0.3, 0.4 and 0.45 percent of the total volume. The soluble salts content and heavy metal content of the compost were found to be within the permissible limits. The MSW compost contained no E. coli and Salmonella. From the results, it can be concluded that, the composting could produce acceptable quality of compost, which can be used as fertilizer or soil amendment.


Author(s):  
O. A. Lipatnikova

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jinghui Fang ◽  
Wei He ◽  
Shan Meng ◽  
Zengjie Jiang ◽  
Jianguang Fang ◽  
...  

The selectivity of Perinereis aibuhitensis larvae on different sediment types was studied using an experimental behavioral device in the lab. There were six types of sediment with different organic matter content: 2.19, 2.30, 2.86, 3.25, 3.51, and 5.52%. The results indicated significant differences in the six treatments’ organic matter content (p < 0.05). When the P. aibuhitensis larvae initially attached to the sediment, the larvae’s density showed no significant difference among the six treatments. The density of larvae decreased gradually during the experimental period. It increased with the increasing organic matter content in sediment at every sampling time, but there was no significant difference (p > 0.05). The larvae’s specific growth rate in the first month was significantly higher than those in the second and third months (p < 0.05). The mortality showed no significance at different sediments in equal sampling times, but the mortality was lower in high organic matter content sediments. This study showed that the P. aibuhitensis larvae did not make an active selection; random selection happened when initially attached to the sediment with different organic matter contents. Higher organic matter content in the sediment was more conducive to larvae survival, and the organic matter content is the limitation factor on the mortality and the density. The different densities in the natural habitat of P. aibuhitensis might occur due to the passive selection by the environment.


2020 ◽  
Vol 8 (05) ◽  
pp. 342-354
Author(s):  
Pengqiang Yang ◽  
Huanghe ◽  
Rujun Gao

Taking different types of sediments as the research object, this research studied the adsorption and release characteristics of phosphorus under different conditions of different temperatures, coexisting heavy metal ion system, organic matter content and sediment particle size. Through used correlation analysis and principal component analysis, it discussed the influence of various factors on the adsorption and release of phosphorus in sediments. The results show that the adsorption of phosphorus by five different types of sediments from different sources reached saturation equilibrium in about 10 hours, and the increasing rates of 0 ℃, 15 ℃ and 30 ℃ are 17.5% ~ 23.7% and 18.2% ~ 38.3%, respectively.  The addition of coexisting heavy metal ion solution accelerated the adsorption of phosphorus in the sediment and reduced the total amount of phosphorus adsorption, that is, heavy metal ions inhibited the adsorption of phosphorus in the sediment; the presence of organic matter in the sediment would reduce its adsorption of phosphorus , Taihu farm and wetland sampling points have the largest sediment organic matter content. Compared with the other three points, the adsorption of phosphorus of these two  points accounted for 20.6% and 22.1%; the adsorption and release of phosphorus by sediment increased with the decrease of particle size. The maximum release rate was 5.216mg/kg-1·h-1. The result of principal component analysis shows that the order of influence on the adsorption and release of phosphorus by sediments is temperature> disturbance> organic matter content> heavy metal ion influence> particle size of sediments.


2018 ◽  
Vol 14 (2) ◽  
pp. 72-84
Author(s):  
C O AKACHUKU ◽  
V P TOMBERE

The study examined the effect of polluted soil on early growth performance of Pentaclethra macro-phlylla. The objectives of the study were to determine the heavy metal content of the soil and the effect on the growth of this species. Soil samples were collected from an abandoned Sunshine battery facto-ry in Essien Udim Local Government Area of Akwa Ibom State using soil auger. The samples, collect-ed at different soil depths and at various distances, were divided into two parts. A part was analysed in the laboratory to determine the heavy metal content of the soil using digestion and atomic absorption methods, while the other part was used in raising Pentaclethra macrophyla seedlings in polypots. The result of analysis of variance of the soil samples considering the distances showed significant differ-ence in the distribution of copper and lead only (P<0.05), while no significant difference occurred among the concentrations of all the heavy metals at different soil depths. The ranges of concentration of metals in the polluted soil samples in mg/kg were Zn (13.90-41.30), Bo (11.40-27.10), Cd (61.10-77.10), Cu (5.35-49.75), Pb (53.10-153.70), As (0.40-4.50) and Se (1.80-4.30), while the control rec-orded the least amount of Pb (2.40-4.30 mg/kg). On the average, seedlings raised in soils collected from the point of waste disposal (epicentre) had the least growth values in terms of total leaf number (166), stem height (21.90cm), branch number (1.4) and branchlet number (8.8). This signifies stunted growth, which is likely due to the high concentrations of Pb and Cu. Factories should therefore be compelled to eliminate heavy metals before disposing their waste into the environment.


2013 ◽  
Vol 464 ◽  
pp. 184-188
Author(s):  
Chong Hao Huang ◽  
Yong Zhang ◽  
Jun Hong Luo

This thesis is based on the target of the sludge which was dehydrated and percolated by sewage treatment plant. It conducts the feasibility analysis for the agricultural usage of sludge in cities, and carries out composting experiment of dehydrated and filtered sludge which lasts for about fifteen days. This thesis also does some research on the techniques of composting and parameters of sludge. This thesis has some researches on the temperature of sludge, moisture, organic matter, pH, total phosphorus content of nitrogen, heavy metals content and forms, the germination rate index (GI), and other changes during the process of composting. The results show that, after the composting, there has a significant decline in moisture content of the sludge and the organic matters; pH remains neutral; nitrogen has declined; total phosphorus increased. Composting can make majority of heavy metals reduced which was absorbed by the plant that means the decline of unstable heavy metal content. After the composting, germinations rate index (GI) is more than 50 percent, which shows that the composting products have no toxicity and indicates the maturity of composting. Through the analysis of the organic matter of the sludge plant, PH, plant nutrients (N, P,) content, heavy metal content and its forms of distribution and germination rate index (GI), it shows that the sludge of this plant has a good agricultural prospect.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Saïda Mouhoun-Chouaki ◽  
Arezki Derridj ◽  
Djaber Tazdaït ◽  
Rym Salah-Tazdaït

Discharging of untreated municipal solid wastes (MSWs) onto land is very widespread in developing countries. The compounds contained in MSW cause a harmful effect to human and environment. Hence, an assessment of the extent of their local impact is of great interest to figure out the pollution they cause. Therefore, this study aimed at evaluating the effects of discharge of solid wastes on soil quality within the landfill of Ain-El-Hammam municipality (Algeria). To achieve this, different soil physicochemical parameters were considered: granulometry, electrical conductivity, pH, organic matter content, and heavy metal concentration. The results indicated the influence of the MSW on the physicochemical characteristics of the soil by enhancing the organic matter content of soil (4.53%) and increasing heavy metal content (Cu, Zn, Cd, Pb, Ni, and Cr), which is a clear indication of the level of pollution they are generating.


2021 ◽  
Vol 51 (5) ◽  
pp. 83-90
Author(s):  
K. N. Narozhnykh

The problem of food contamination by heavy metals due to their accumulation in biosystems as a result of anthropogenic influences has been studied. The results of cadmium, lead, iron and manganese in cattle from the Novosibirsk Region and the Altai Territory are presented. The purpose of the study was to assess the impact of the ecological and geographical factor on the heavy metal content in the lungs of Hereford bulls. Lung samples were taken from 31 clinically healthy Hereford bulls aged 16-18 months. Sample preparation was carried out in accordance with GOST 26929-94 and 30178-96. The chemical composition of the samples was determined by atomic absorption spectrometry with flame and electrothermal atomization. The median values of the content of cadmium, lead, iron and manganese in the lungs of bull-calf were in the range of 0,01-0,12; 0,07-0,11; 70,9-89,1 and 0,3-0,4 mg/kg. The phenotypic variability of the level of iron and manganese was relatively low, while that of lead and cadmium was high. The dispersions of lead and cadmium levels in the animal groups studied were homogeneous, manganese and iron variants were heterogeneous. The influence of the ecological and geographical factor is characteristic only for cadmium levels. For manganese, iron, lead and cadmium the calculated reference ranges are: 0-1.12; 0-148.1 and 0-0.170 mg/kg respectively. They can serve as a guideline for Hereford cattle bred in the territories of Krasnozersky, Novosibirsky and Maslyaninsky districts of the Novosibirsk region and the Tselinny district of the Altai Territory.


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