Impacts of heavy metals and soil properties at a Nigerian e-waste site on soil microbial community

Multivariate analysis of the effects of age, particle size and landfill depth on heavy metals pollution content of closed and active landfill precursors

Distribution of radionuclides and heavy metals in the bituminous sand deposit in Ogun State, Nigeria – A multi-dimensional pollution, health and radiological risk assessment

Heavy metal contamination from landfills has become a worldwide problem. Concerns have been raised over their impacts on human health and the environment. Soil amendment-assisted phytoremediation is rapidly gaining attention as a biotechnology to accelerate heavy metal (HM) removal from contaminated soils or immobilize the HMs. How different amendments influence this process is still an important research question. This study quantified the bioaccumulation factor (BAF) and removal efficiency (RE) of HMs by wheat (Triticum aestivum), bean (Vicia faba), and rocca (Eruca sativa) in a pot experiment with biochar (BC), humic substances (HS) (in the form of potassium humate), and iron oxide (FO) amendments to clarify the effect of these treatments on phytoremediation. Each amendment was applied to the soil at a rate of 20 g kg−1 soil, with unamended soil as a control. The results indicated that the available HMs were significantly decreased in the amended soils (p < 0.05) as compared with untreated soil. Plant concentrations of all the studied metals decreased with the soil amendments as compared to untreated soils. BAF was higher than 1 in all plants, and RE indicated the plants were most efficient in removing Pb from the studied soils. In general, soil amendments aided soil HM immobilization and reduced the accumulation of HMs in the cultivated plants. The studied amendments could be further explored as tools to remediate contaminated sites.

Enhanced Immobilization and Phytoremediation of Heavy Metals in Landfill Contaminated Soils

Establishing a human health risk assessment methodology for metal species and its application of Cr 6+ in groundwater environments.

Environmental and health risk posed by heavy metals from municipal landfill cannot be over emphasized. However, the toxicity and fate of metal in the soil is dependent on its chemical form and therefore quantification of the different forms of metal is more meaningful than the estimation of its total concentration. This study investigated the chemical form and potential hazards of heavy metal pollution at two municipal landfills in Sagamu, Ogun state, Nigeria. Soil samples were collected around the landfills and chemical form of Cu, Zn, Cd, Pb, and Fe were studied, using the Tessier Five-step sequential chemical extraction procedure. The results showed that Cu and Fe were speciated into residual fractions with averages of 23.9 and 31.3% respectively, while Cd and Zn were associated with Carbonate fractions with respective averages of 20.3 and 20.6%. The order of mobility and bioavailability of these metals are: Cd > Pb > Cu > Zn > Fe. A comparison of the result of total extractible metals with sta...

https://www.tandfonline.com/doi/pdf/10.1080/09542299.2016.1203267

Oluwaseun Anselm

Papers

Chemical speciation of some heavy metals and human health risk assessment in soil around two municipal dumpsites in Sagamu, Ogun state, Nigeria