A study of the removal of toxic metal ions in drinking water using modified and unmodified clays.

摘要

Water is absolutely essential for existence, development and preservations of all human life, making it an essential commodity in the world. People living in third world countries are suffering from a water crisis that has become a major health issue. The lack of available clean water contributes to numerous waterborne and water-washed diseases, causing the death of millions of people annually and hindering the development of communities. Clearly this is a major health issue in the world today that must be addressed to save the lives of the millions of people that are dying from preventable ailments. We believe the solution to this crisis, among many, is L3 Technologies (Low cost, Locally available, and Low technologies).;The presence of heavy metals in potable water can cause reduced growth and development, cancer, organ damage, and in extreme cases death. The objective of the research was to remove harmful heavy metals from water sources using different types of clay. We tested for three heavy metals which consisted of copper, cadmium, and lead. We hypothesised that clay has the capability to remove heavy metals, due to clay's ion exchange capability. Ion exchange process in these clays is reversible chemical reaction that takes place between ions held near the mineral surface by unbalanced electrical charges within the structural framework and metal ions in a solution in contact with the clay. In the laboratory we have contaminated the water using the specific heavy metals, at various concentrations that are representing samples from the real world. Afterwards we used clay and inserted into a tea bag (porous material), and took samples out every five minute interval till thirty minutes. They resulting samples were analysed using ICP-AES (Inductively coupled plasma atomic emission spectroscopy). The removal efficiency was found to be maximum at the first five minutes of the experiment. The clay was found to be effective in removal of heavy metals from water. We developed a low cost and low-tech method for removal of heavy metals from drinking water, with nearly 95% efficiency.