Abstract

Water contamination by heavy metals is a growing environmental concern, particularly in urban markets such as 
Ggaba Market in Uganda, where human activities contribute to pollution. This study aims to assess the 
concentration of selected heavy metals; lead (Pb), iron (Fe), nickel (Ni), cadmium (Cd), and mercury (Hg) in water 
from Ggaba Market and evaluate the effectiveness of bone char as an adsorbent for their removal. Water samples 
were collected from two different locations, analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP
MS), and subjected to biochar treatment. The results indicated high concentrations of heavy metals in untreated 
water samples, with iron, lead, and cadmium exceeding World Health Organization (WHO) safety limits. Biochar 
treatment significantly reduced the levels of heaviest metals, particularly lead, iron, and cadmium, achieving near
complete removal. However, nickel and mercury were less effectively removed, indicating the need for optimization 
or complementary treatment methods. These findings highlight the severity of heavy metal contamination in Ggaba 
Market and underscore the potential of biochar as a cost-effective and eco-friendly water purification technique. The 
study recommends the adoption of biochar in water treatment systems, further research into its optimization for 
mercury and nickel removal, and increased public awareness of water pollution risks.