Department of Chemistry, College of Natural and Computational Sciences, Ambo University, P. O. Box 19, Ambo, Ethiopia.
Department of Chemistry, College of Natural and Computational Sciences, Haramaya University, P. O. Box 138, Dire Dawa, Ethiopia.
Environ Sci Pollut Res Int. 2019 Jun;26(18):18593-18603. doi: 10.1007/s11356-019-05018-z. Epub 2019 May 3.
Surface dusts from electronic and electrical material maintenance workshops may present significant environmental contamination. The aim of this study was to determine levels of selected heavy metals (Cu, Ni, Co, Cd, Cr, Pb, Zn, and Fe) in surface dust samples collected from electronic and electrical device maintenance workshops located in Ambo, Gedo, and Nekemte towns in Ethiopia. An optimized wet digestion procedure (acid mixture, 3 mL HNO, 2 mL HClO, and HO; digestion time, 2 h; digestion temperature, 200 °C) was employed prior to the metals determination by flame atomic absorption spectroscopy. The average amounts of the metals were found to be in the ranges of 73,970-58,980, 59,290-51,120, 8570-5778, 1273-1126, 708.9-261.6, 111.7-101.0, 114.9-89.50, and 12.30-9.620 mg/kg for Pb, Fe, Cu, Cr, Zn, Co, Ni, and Cd, respectively. The results showed that the investigated surface dust samples contained significant levels of the analyzed heavy metals compared to soil samples collected from the corresponding control sites. The heavy metal concentrations in the investigated samples from the three towns followed a decreasing order Pb > Fe >> Cu >> Cr > Zn > Co > Ni > Cd, indicating the presence of elevated amount of Pb in the surface dust samples. The significantly high levels of heavy metals detected in all surface dust samples from electronic and electrical device maintenance shops could be inferred to the seepage of these metals from electronic materials during the maintenance procedures. Based on the result obtained, we strongly recommend a strict monitoring and disposal (policy issue) of wastes generated from electronic and electrical device maintenance shops.
电子和电气材料维修车间的表面灰尘可能会造成严重的环境污染。本研究的目的是测定埃塞俄比亚安博、盖多和内克姆特镇电子和电气设备维修车间采集的表面灰尘样本中选定重金属（铜、镍、钴、镉、铬、铅、锌和铁）的含量。采用优化的湿法消解程序（酸混合物 3mL HNO、2mL HClO 和 H2O；消解时间 2h；消解温度 200°C）对金属进行消解，然后采用火焰原子吸收光谱法进行测定。发现金属的平均含量范围分别为 Pb（铅）73970-58980、Fe（铁）59290-51120、Cu（铜）8570-5778、Cr（铬）1273-1126、Zn（锌）708.9-261.6、Co（钴）111.7-101.0、Ni（镍）114.9-89.50 和 Cd（镉）12.30-9.620mg/kg。结果表明，与从相应对照点采集的土壤样本相比，调查的表面灰尘样本中含有大量分析重金属。三个城镇调查样本中的重金属浓度按 Pb（铅）>Fe（铁）>Cu（铜）>Cr（铬）>Zn（锌）>Co（钴）>Ni（镍）>Cd（镉）的顺序递减，表明表面灰尘样本中存在大量 Pb（铅）。所有电子和电气设备维修车间表面灰尘样本中检测到的重金属含量显著较高，这可能是由于在维修过程中，这些金属从电子材料中渗出所致。根据所获得的结果，我们强烈建议对电子和电气设备维修车间产生的废物进行严格监测和处理（政策问题）。
