Characterization and Purification of Groundwater Using Carbon Dot Impregnated into Biosand Filters: A Case of Warri and its Environs, Niger Delta, Nigeria

Abstract

The release of toxic gases and spills into the ecosystem prior to anthropogenic activities can increase the level of pollutants in hydrological systems. This possibly influences the number of harmful substances that percolate into aquifers. The drilling of polluted aquifers for domestic and drinking purposes and consuming such water untreated consequently increases the risk of developing water-related health issues. The study presents the quality and purification of groundwater samples in the Warri metropolis through water-quality analysis and biosand filtration method Aappropriatemethod (Appropriate Technology Enableds Development technique), respectively. The pH results were very low in all the groundwater samples presented with values ranging from 5.16±0.03 to 6.81±0.09, except for table water samples serving as controls. Total iron concentration was above the regulatory limits of 1.00 mg/L in some locations, recording concentrations between 0.758±0.340 mg/L and 1.204±0.740 mg/L. Groundwater samples contaminated with coliform bacteria were recorded in some locations. It suggests that the groundwater quality of the studied locations is relatively poor and unsafe for drinking untreated. This is possibly due to high hydrocarbon exploration and production activities, together with other anthropogenic activities in the area. Nevertheless, the filtration of the groundwater samples with biosand filter effectively improved the taste, reduced the iron content, removed particles, and eliminated microbial contaminations. However, the pH was relatively low after filtration and was further enhanced in the filtration with the carbon dots. The carbon dot filtration can be viewed as a better substitute to for granites in the filter beds of the biosand filter unit to influence pH conformance.