Water Quality and Contamination

Water Quality and Contamination
SCI 207: Dependence of Man on the Environment















INTRODUCTION
Ground water is present below the surface in porous rocks and is susceptible to contamination by natural and especially human related activities. Large amounts of chemicals like soap and detergents, fertilizers and pesticides, pharmaceutical by-products are discharged in to fresh water aquifers every day. These contaminants leach in to the soil and dissolve in ground water. Different contaminants have different rates of solubility and degradation once they reach the underground water table either by simple flow or by the downward movement of rain water. The ground water may become contaminated with both organic and inorganic substances especially heavy metals like Cadmium, Chromium and Nickel, etc. (Christensen et al, 2001). Pharmaceutical wastes can cause cancer in human cells. (Krifa et al. 2013). Many pharmaceutically active chemicals reach groundwater sources almost untreated and cause contamination. (Herber, 2002).   Increase in the emissions of carbon dioxide by burning fossil fuels is the single largest cause of environmental degradation resulting not only in global warming but also causing acid rain which alters the pH of ground water. Water is a universal solvent; however, its dissolving properties are very sensitive to changes in temperature and pH. Global economic growth has, unfortunately, resulted in high levels of carbon dioxide emissions worldwide with the current annual rate at 3.3% from 1.3% in the last decade. (Canadell et al, 2007). The demands of agricultural output have put a lot pressure on fresh water sources. Rapid industrialization has led to huge increase in the usage of ground water. The untreated industrial wastes are released back in to rivers and streams causing further pollution. Industrial units are the biggest users of ground water today with a share of almost 22% of the total water supply available in the...