Investigations and comparison of a conventional sand filter and a modified sand filter for water purification.

Abstract

Water being a depleting resource needs to be treated in a sustainable way. The oldest-natural method of purifying drinking water is to use sand filters, made by using layers of sand and gravel placed at proportional depths and sizes. A few drawbacks like requirement of further disinfection, bad odour, inefficiency in removing chemicals like cholrine, fertilizers etc,. does not allow the usage of conventional method. Hence in this research work a Modified Sand Filter is constructed by partial replacement of sand with Granulated Activated Carbon in order to overcome all possible drawbacks.GAC is a locally available material made from materials like coal, wood, coconut shell, nutshells or any carbonaceous materials, which makes it a “sustainable, cost efficient and eco friendly material” as it is a reuse material. The principle of water purification through GAC is adsorption of contaminants in the microscopic pores on its surface. GAC has small, low-volume pores that increase the surface area available for adsorption or chemical reactions. Due to its high degree of micro porosity, one gram of activated carbon has a surface area in excess of 3,000 m2 allowing it to remove particles ranging from 0.5 –10 microns and therefore removes pesticides, chlorides and microplastics as well.It is observed from experimental results that various physical and chemical parameters (taste, odour, pH, turbidity, chloride and hardness) have been improved (IS 10500: 2012) after using the Modified Sand Filter. Therefore further experimentation can be done to check its efficiency in removal of other hazardous substances.