Solid-Phase Partitioning and Leaching Behavior of Pb and Zn from Playground Soils in Kabwe, Zambia

Toxics

Pawit Tangviroon¹  Toshifumi Igarashi¹  Tsutomu Sato¹  Mayumi Ito¹  Walubita Mufalo²  Mayumi Ishizuka³  Shouta Nakayama³  Hokuto Nakata³  Meki Chirwa⁴  Imasiku Nyambe⁴ 

[1] Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan;Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan;Faculty of Veterinary Medicine, Hokkaido University, Kita 18, Nishi 9, Kita-Ku, Sapporo 060-0818, Japan;IWRM Centre/Geology Department, School of Mines, The University of Zambia, Lusaka 32379, Zambia;

关键词: contamination;    lead;    zinc;    bio-accessibility;    leaching;    Kabwe;   

DOI  :  10.3390/toxics9100248

来源: DOAJ

【 摘 要 】

Zambia’s Kabwe mine wastes (KMWs) are responsible for contaminating the surrounding soil and dust in the Kabwe district. Unfortunately, these wastes arise from the historical mining activities of lead (Pb) and Zinc (Zn), which lacked adequate waste management strategies. As a result, potentially toxic elements (PTEs) (Pb and Zn) spread across the Kabwe district. To assess the soil pollution derived from previous mining activities, we studied topsoil samples (n = 8) from the school playground soils (SPs). In this study, the degree of contamination, geochemical partitioning, and leachability, coupled with the release and retention of Pb and Zn, were studied. The SPs were classified as extremely enriched (EF > 40) and contaminated with Pb (I_geo > 5). On average, Pb (up to 89%) and Zn (up to 69%) were bound with exchangeable, weak acid-soluble, reducible and oxidizable phases, which are considered as ’geochemically mobile’ phases in the environment. The leachates from the soils (n = 5) exceeded the Zambian standard (ZS: 190:2010) for Pb in potable drinking water (Pb < 0.01 mg/L). Furthermore, the spatial distribution of Pb and Zn showed a significant reduction in contents of Pb and Zn with the distance from the mine area.

【 授权许可】

Unknown