Sustainable Chemistry for the Environment (Aug 2023)
Assessments of microbial and heavy metal contaminations in water supply systems at the University of Environment and Sustainable Development in Ghana
Abstract
The main component of the environment that is essential for human existence on earth is availability of quality water. As human activity has evolved, particularly in the industrial, household, and agricultural sectors, groundwater systems are exposed to various contaminants. Groundwater is one of the main sources of water at the University of Environment and Sustainable Development (UESD) in Ghana. However, no research has been carried out to assess the levels of microbial load and heavy metal toxicants in water transmission systems at UESD. In this current study, we investigated the levels of selected heavy metals and microbial load present in the water supply systems at UESD. Water samples were collected from four (4) different zones at the University. Atomic absorption spectroscopy (AAS) was used to analyse the levels of eleven heavy metals (Fe, Cd, Cu, Cr, Zn, Mn, Co, Hg, Pb, Ni and As), whereas correct growth media were used to estimate microbial loads. Observations for water samples were compared to the permissible limits, using one-sample t-tests. Similarly, paired t-tests and Tukey’s honestly significant difference were used to compare observations between water samples from the zones. Water quality indicators (hazard quotient (HQ) and health hazard index (HI)) were used to examine any potential health risks. In addition, water quality index (WQI) was used to predict the quality of the groundwater at UESD campus. The results showed that the levels of Fe, Cd, Cu, Cr, Zn, Mn, Co and Hg were within the permissible limits. However, the levels of Pb, Ni and As for all the sampling zones were significantly higher than the permissible limits. The results of HI and HQ for the oral ingestion pathways of the metals were within the accepted levels. The result of WQI showed that heavy metals would contaminate groundwater in wells and the natural pond on UESD campus. Total coliforms, faecal coliforms and Escherichia coli colony-forming units present in the water samples were significantly higher than the acceptable levels, indicating a possible health risk when ingested. Therefore, we recommend water recycling and regular water quality monitoring programs at the University.
