Groundwater Pollution and Remediation

摘要

Groundwater pollution is imminent in most developing countries as a result of increased anthropogenic activities apart from possible natural pollutants. This study reviewed groundwater pollution and discussed possible remediation measures. Sources of pollution can be categorized into two major types: point source pollution and non-point source pollution. Point source pollution (e.g. municipal sewage treatment plant and industrial plant, intense evaporation in shallow aquifers, degradation of water sources in areas located in geothermal/volcanic fields, and rock oxidation) is a single identify localized source while non-point source pollution (diffuse sources such as human land use, land use changes, chemical reactions of elements in the air or in the water and pollutes runoff from agricultural areas draining into a river) is characterized by multiple discharge point. Point source is relatively easy to identify, quantify and control. On the other hand, non-point source is difficult to monitor and control because the pollution cannot be traced to a single point of discharge. Pollution occurrence depends on the level of contaminant transported. Contaminants can be transported through filtration, sorption, chemical processes, microbiological decomposition and dilution. Groundwater pollution may cause ecosystem imbalance apart from severe sickness which may lead to death. Prevention of groundwater pollution is more appropriate than remediation. Such preventive measures include proper waste disposal, monitoring of hazardous materials, conducting environmental audit periodically and intensifying health education while remediation includes stream stripping, oxygen sparging, bioremediation, chemical oxidation and thermal treatment. This study revealed two main sources (point source and non-point source) of pollution with non-point pollution more difficult to remediate due to extent of spread. In addition, most pollution of groundwater is anthropocentric and can be prevented through intensive health education.