LOW COST WATER TREATMENT USING NATURAL MATERIALS: A CASE STUDY FOR ASMARA / Kostnadseffektiv vattenrening med hjälp av naturliga material: Tillämpning för Asmara
The high cost of water treatment has rendered provision of good quality water difficult in the developing world. More than 1 billion people are believed to have no access to safe drinking water. Costs of chemicals, filter media and power are the most important parameters that have to be considered in providing affordable treatment. In this paper use of natural materials for improving water treatment system is discussed and a case study for Asmara, the capital of Eritrea, is outlined. An overview of the water supply indicates that here is enough water resource for the present and near future demand. However, the water quality does not meet the WHO guidelines. This is due to both poor performance of the treatment plants and distribution system. High percentage of unaccounted-for-water is observed (about 40 %). It has become critical co improve the water quality through modification of the treatment plants design and operation. Considering the existing financial constraints, effective and low cost treatment using natural materials are suggested. Moringa Oleifera for raw water coagulation and sludge conditioning as well as pumice for filtration has been considered in the study. A combination of natural materials and hydraulic system should be assessed for areas in the developing world.