Distribution of Cu, Zn, Pb, Cr, Ni, Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determin...Distribution of Cu, Zn, Pb, Cr, Ni, Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined. Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m^2. Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210, respectively. Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carriers and their distribution. Heavy elements were mainly concentrated inside the particle size fraction 〈 50 μm. Their levels decreased with distance increasing from the industry. According to the reference soil, enrichment factors were about 10, 15, 32 and 100 times for Zn, Pb, Cu, and Cr, respectively inside the particle size fraction 〈 50 μm on the closest sites to the industry. The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste. Heavy elements were entrapped inside agglomerates of sulfates, phosphates and iron oxihydroxides in a diffused shape. Polonium-210 with an enrichment factor of about 56, showed the same behavior of the spatial distribution of the trace elements.展开更多
<p> The concentrations and distribution of naturally occurring radionuclides <span><span><span><span>(</span><sup><span>238</span></sup><span>U, </s...<p> The concentrations and distribution of naturally occurring radionuclides <span><span><span><span>(</span><sup><span>238</span></sup><span>U, </span><sup><span>235</span></sup><span>U, </span><sup><span>234</span></sup><span>U, </span><sup><span>230</span></sup><span>Th, </span><sup><span>226</span></sup><span>Ra, </span><sup><span>210</span></sup><span>Pb, </span><sup><span>232</span></sup><span>Th, </span><sup><span>228</span></sup><span>Ra, and </span><sup><span>40</span></sup><span>K)</span></span></span></span><span><span><span><span> were determined by alpha and gamma spectrometry in soil and sediments collected from Luilu and Dilala rivers located in the mining district of Kolwezi (Lualaba Province) of the Democratic Republic of the Congo. The average concentrations of </span><sup><span>238</span></sup><span>U and </span><sup><span>226</span></sup><span>Ra in the analyzed samples were 5</span></span></span></span><span><span><span> </span></span></span><span><span><span>-</span></span></span><span><span><span> </span></span></span><span><span><span>10 times higher than the world average values for soil provided by the </span></span></span><span><span><span>United Nations Scientific Committee on the Effects of Atomic Radiation. However,</span></span></span><span><span><span><span> the average concentrations of </span><sup><span>232</span></sup><span>Th were found similar to the world average. In both river basins, artisanal mining activities and</span></span></span></span><span><span><span> mineral washing sites displayed the higher concentration values of radionuclides. The mean values of health risk indices calculated for those sites were found sig</span></span></span><span><span><span>nificantly higher compared to world average levels. Radiation protection measures seem needed to ensure the radiation safety of local populations.</span></span></span> </p> <p> <span><span><span><br /> </span></span></span> </p> <p> <span style="font-size:16px;"><strong>Graphical Abstract</strong></span> </p> <p> <span><展开更多
基金supported by the research grants program of the Lebanese Council for Scientific Research
文摘Distribution of Cu, Zn, Pb, Cr, Ni, Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined. Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m^2. Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210, respectively. Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carriers and their distribution. Heavy elements were mainly concentrated inside the particle size fraction 〈 50 μm. Their levels decreased with distance increasing from the industry. According to the reference soil, enrichment factors were about 10, 15, 32 and 100 times for Zn, Pb, Cu, and Cr, respectively inside the particle size fraction 〈 50 μm on the closest sites to the industry. The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste. Heavy elements were entrapped inside agglomerates of sulfates, phosphates and iron oxihydroxides in a diffused shape. Polonium-210 with an enrichment factor of about 56, showed the same behavior of the spatial distribution of the trace elements.
文摘<p> The concentrations and distribution of naturally occurring radionuclides <span><span><span><span>(</span><sup><span>238</span></sup><span>U, </span><sup><span>235</span></sup><span>U, </span><sup><span>234</span></sup><span>U, </span><sup><span>230</span></sup><span>Th, </span><sup><span>226</span></sup><span>Ra, </span><sup><span>210</span></sup><span>Pb, </span><sup><span>232</span></sup><span>Th, </span><sup><span>228</span></sup><span>Ra, and </span><sup><span>40</span></sup><span>K)</span></span></span></span><span><span><span><span> were determined by alpha and gamma spectrometry in soil and sediments collected from Luilu and Dilala rivers located in the mining district of Kolwezi (Lualaba Province) of the Democratic Republic of the Congo. The average concentrations of </span><sup><span>238</span></sup><span>U and </span><sup><span>226</span></sup><span>Ra in the analyzed samples were 5</span></span></span></span><span><span><span> </span></span></span><span><span><span>-</span></span></span><span><span><span> </span></span></span><span><span><span>10 times higher than the world average values for soil provided by the </span></span></span><span><span><span>United Nations Scientific Committee on the Effects of Atomic Radiation. However,</span></span></span><span><span><span><span> the average concentrations of </span><sup><span>232</span></sup><span>Th were found similar to the world average. In both river basins, artisanal mining activities and</span></span></span></span><span><span><span> mineral washing sites displayed the higher concentration values of radionuclides. The mean values of health risk indices calculated for those sites were found sig</span></span></span><span><span><span>nificantly higher compared to world average levels. Radiation protection measures seem needed to ensure the radiation safety of local populations.</span></span></span> </p> <p> <span><span><span><br /> </span></span></span> </p> <p> <span style="font-size:16px;"><strong>Graphical Abstract</strong></span> </p> <p> <span><
