VARIASI WAKTU KONTAK PADA FILTER MANGANESE GREENSAND DAN PASIR SILIKA TERHADAP PENURUNAN MANGAN (Mn) DALAM AIR BERSIH

Abstract

PT Dirgantara Indonesia is a company produces aircraft and weapons. Monitoring the quality industrial environment is important as stipulated in PMK No.70 of 2016 concerning Standards and Requirements for Industrial Occupational Health. Clean water quality parameters that must be checked is manganese (Mn) levels, if the concentration is above the quality standard it can affect employee health. The results of laboratory examinations of manganese levels clean water in office buildings amounted to 0,66 mg/liter, while the quality standard for manganese levels allowed is 0,5 mg/liter. The purpose of this study was to reduce manganese levels in clean water commonly used by employees using filters with Manganese Greensand and Silica Sand media. This study uses the experimental type of post-test design with control, the independent variable water contact time and the dependent variable manganese (Mn) levels. Sampling was carried out by grab sampling, sample population was an office building reservoir with volume 19 liters. Examination of manganese levels before and after treatment with contact time three minutes, five minutes and seven minutes using the SNI 6989.5: 2009 method of manganese (Mn) Test Method by Atomic Absorption Spectrophotometry (AAS) - Flame. Based on the results of the research there is significant difference between manganese levels with variations contact time in the Kruskal Wallis test. The percentage reduction in manganese levels was greatest at contact time of seven minutes, which amounted to 87,36%. The use of filters with manganese greensand and silica sand is good for clean water treatment process in office buildings.