Analyses of Metal Cations in the Bottom Ash of Hospital Incinerator and Open Waste Burning Dumpsite in Umuahia, Abia State, Nigeria

Abstract

This study determined the level of metal cations in incinerator bottom ash and open burning dumpsite in Medical Centre, Umuahia.   Samples were collected at the depths of 0-15 cm, 15-30 cm from bottom ash, 0-15cm, 15-30cm and 30-45cm from soil within hospital   open dumpsite.  Metal cations were analyzed using the absorption spectrophotometer (AAS) and results subjected to principal component analysis (PCA), geo-accumulation (I_-geo) and Contamination/Pollution Index (C/PI) indices. Data presented using ANOVA, and mean separated with (LSD) at P≤0.05 and p≤ 0.01.   Effect of soil depths on cation variability in ash and soil was significant at p≤ 0.05 and ≤ 0.01 levels respectively. Cations    decreased in  order of : Zn²⁺  ≥Mn²⁺ ≥ Cu²⁺  ≥ Cr²⁺≥ Pb²⁺ Cd²⁺in  bottom ash;  Zn²⁺  ≥ Cu²⁺  ≥²⁺ Mn²⁺≥ Cr²⁺  ≥ Pb²⁺≥ Cd²⁺ in open dumpsite.  PCA indicate high loadings on Cu²⁺, Pb²⁺, Mn²⁺, Cd²⁺  in ash   while   dumpsite loaded with Cd²⁺ , Cr²⁺,  Mn²⁺ and Zn²⁺. C/PI decreased in order of: Cu²⁺ ≥Zn²⁺≥Cr²⁺≥Mn²⁺≥ Cd²⁺/Pb²⁺  for bottom ash   ; Cu²⁺ ≥Zn²⁺ ≥Cr²⁺ ≥Mn²⁺ ≥Pb²⁺ ≥Cd²⁺ for  open dumpsite indicating slight to very slight contamination respectively.  I_-geo was in decreased order of: Cd²⁺≥Pb²⁺≥Mn²⁺≥Cr²⁺≥Cu²⁺≥Zn²⁺in ash and Cd²⁺ ≥ Pb²⁺ ≥Mn²⁺≥Cr²⁺≥Zn²⁺≥Cu²⁺in dumpsite indicating uncontaminated to moderately status. Therefore, incinerator bottom ash should be properly managed through pretreatment and landfill disposal and open burning should be discouraged to avert further environmental pollution.