Utilization of Bio-sand Filter Technology to Reduce The Hardness of Groundwater in Bangunjiwo Village, Yogyakarta

Water is the most critical requirement for the community for daily needs. Groundwater in Bangunjiwo Village, Yogyakarta has a high level of hardness. groundwater in the village contains high Magnesium (Mg2+) and Calcium (Ca2+) reaches more than 180 ppm. The purpose of this study is to reduce the level of hardness of water in Bagunjiwo Village using bio-sand-filter technology. The sampling of groundwater in Bangunjiwo Village is done randomly at several different points. Water filtration with bio-sand-filter technology uses sand media by growing biofilm layers. Biofilm layers made from layers include gravel with a diameter of 2 cm, small gravel with a diameter of 1 cm, zeolites with a diameter of 0.5 cm, and layers of clay. Each layer is bordered by gauze. The arrangement is soaked in water for 21 days, resulting in biofilms in the media. The results of screening with bio-sand-filter technology showed a decrease in hardness of groundwater reached 78.67 % with a discharge of 0.5 litres per minute. Bio-sand-filters can absorb the content of Magnesium and Calcium even pathogens in the water. Bio-sand-filter technology is expected to be able to overcome community problems in Bangunjiwo Village, Yogyakarta.