Heavy metal contamination in water supplies has steadily increased as a result of over population and the expansion of industrial activities (Wang & Peng, 2010). The presence of heavy metals in water supplies is of significant concern due to their toxicity to humans, animals, and plants. Pollutants include cyanide, silver, cobalt, manganese, aluminum, magnesium, arsenic, copper, iron, lead, and mercury. The application of natural zeolites for water treatment is a promising technique in the environmental cleaning process (Wang & Peng, 2010). The utilization of natural zeolites has focused on the removal of ammonium and heavy metals through ion exchange.

A study by Mamba et al. (2009) examined metal removal from water contaminated by heavy metals using HCl-activated clinoptilolite and bacteria. The results indicated that clinoptilolite removed 98 percent of copper, iron, cobalt, and gold. Researchers concluded that clinoptilolite successfully removes metal recovery from mining and mineral processing solutions. It is effective as a water decontaminate.

Turkman et al. (2004) examined the effect of pretreated and untreated clinoptilolite zeolite in the removal of lead, cadmium, nickel, and zinc from wastewaters. Zeolite demonstrated a 96 percent removal efficiency for lead, zinc, and cadmium. The maximum sorption capacities for untreated zeolite were measured as 0.18 and 0.12meq/g, whereas pretreated minerals demonstrated a range of 0.72 and 0.41 meq Cd/g.

Moreno et al. (2001) conducted a series of decontamination tests to measure the impact of zeolite on the purification of acid mine waters. The results suggest that zeolitic materials can be successfully used for heavy metal adsorption in the water purification process. Doses of 5-30 g of zeolite/L were applied based on recorded levels of heavy metals. Researchers found that zeolite increases general pH of ponds, which cause metal-bearing solid phases to precipitate, enhancing the efficiency of the decontamination process (Moreno et al., 2001).