PRELIMINARY ANALYSIS OF WATER PRODUCTION RATE AND TURBIDITY IN SOURCE WATER FROM MOUNT MERAPI USING A MULTI-LAYER SAND FILTER

Setya Winarno

Abstract: In Indonesia, little importance is placed on the coverage of water supply services and even less importance is focused on water filtration. Today, many people in the surroundings of Merapi Mountain, Yogyakarta City, Indonesia are utilizing one-layer sand filtration, which is frequently used as a robust method of removing suspended solids from water. Because they have a single layer of sand filtration medium with a diameter of about 0.5–3 mm, sand filters remove only relatively large solids. This paper elaborates the effective size of each sand granule with two sand layers in terms of the water production rate and turbidity in order to benefit people in the surroundings of Mount Merapi. A flow rate study was conducted by creating three parallel sand boxes (length = 20 cm, width = 30 cm, and height = 80 cm). Each box consisted of two sand layers with a height of 20 cm each. Box 1 was filled with 20 cm of 0.5-mm sand at the top and 20 cm of 0.3-mm sand at the bottom. Box 2 had 20 cm of 1.0-mm sand at the top and 20 cm of 0.5-mm sand at the bottom, while Box 3 had 20 cm of 1.5-mm sand at the top and 20 cm of 1.0-mm sand at the bottom. The three sand boxes were then compared. From the obtained results, the relationship between average flow rate and turbidity was found and had a positive linear trend of 4.881 NTU/Lh-1 . To fulfil the Decree of the Indonesian Health Minister No. 907/MENKES/SK/VII/2002, which specifies that the maximum turbidity for clean water is 5 NTU, Box 2 is an effective solution with a flow rate of up to 2.9 Lh-1 . However, long-term investigations should be conducted to assess how these relationships change over the expected lifetime of the sand filter.

Keywords: Sourcewater, Production Rate, Turbidity, Sand Filter

DOI: https://doi.org/10.15623/ijret.2017.0603006