Iranian J Env Health Sci Eng, 2005, Vol.2, No.2, pp.12-16 12 Evaluation of the Efficiency of Clay Pots in Removal of Water Impurities * K Naddafi 1 , AM Mahvi 1 , S Nasseri 1 , M Mokhtari 1 , H Zeraati 2 1 Dept. of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Iran 2 Dept. of Epidemiology & Biostatistics, School of Public Health, Tehran University of Medical Sciences, Iran (First received 20 January 2005; accepted in revised form 13 September 2005) ABSTRACT Recently, inexpensive technologies for drinking water supply in small communities are highly consid- ered in developing countries. One of these technologies is the application of ceramic filters that are usually made of diatomaceous earth or clay soil. This research was carried out to determine the effi- ciency of clay pots (as a filter) in removing water impurities. Pilot and the related clay parts were manufactured and its efficiency in removing TDS, hardness, NO3 - , color and turbidity was measured by passing water through the clay pipes. The results showed that the clay filters had not the potential to remove hardness, EC, TDS and nitrate of water. However, they showed excellent efficiency in turbidity removal (≥ 90%) and could significantly decrease the color of the water (≥ 60%). Keywords: Water treatment, Ceramic filters, Small communities INTRODUCTION The crisis of water shortage is still the most im- portant global challenge of the twenty first century. In quantitative term, although 75 per- cent of the earth surface is covered by water, fresh water has the share of only 3 percent of this amount, from which only one percent is available for different human uses (AWWA, 1999; Hammer, 2001). Iran is located in a zone where its average an- nual rainfall is less than 1/3 of the average global annual rainfalls. Furthermore, the local and time distribution of the rainfalls are highly unsuitable and major part of the country is dry with low-water sources. There are parts in Iran where there is neither a usable current surface water nor consumable underground water; therefore, the government has no other alterna- tive than providing water demand of the resi- dents in these regions from other sources (Kor- davani, 2002). This constraint imposes large amount of costs to the government. Based on the reports of World Health Organiza- tion (WHO), nearly 85 percent out of 1.5 billion population of the world has no access to healthy and uncontaminated water and live in small communities who need safe drinking water. A large part of Iran is dwelled by scattered and small communities Because of the high costs of water transfer projects and water treatment plant designs for small communities, inexpen- sive and appropriate technologies including Point of Use (POU) and Point of Entry (POE) *Corresponding author: Tel: +98 21 88954914, Fax: +98 21 88950188, E-mail: k_naddafee@yahoo.com Iranian J Env Health Sci Eng, 2005, Vol.2, No.2, pp.12-16