Evaluasi Lokasi Titik Sampling Debu Jatuh terhadap Lokasi Cerobong di PT. Krakatau Steel

Abstract

PT Krakatau Steel as the biggest steel industry in Southeast Asia having seven main factories, has an inclination to produce pollutant materials to environment surrounding, one of them is falling dust. The amount of increasing population, transportation condition and vegetation surround the factories affect distribution change and direction of falling dust spread, by watching at those matters above and the early condition of Cilegon city when PT Krakatau Steel exist. The present study has purpose at knowing the direction frequency and the wind velocity to the falling dust spread produced through PT Krakatau Steel stacks and to evaluate sampling location point toward the cerobong location of PT Krakatau Steel. A method in the study comprised taking of falling dust sample in 50 sampling points then it was taken 15 samples from 3 areas consisted of urban, village and industry having dust weight more than the quality standard as big as 20 ton/km /month in industrial area and 10 ton/km2/month in settlement area, according to the Governmental Regulation No. 41 of 1999 on Control of the Air Pollution. The sample then analyzed with a spectrometry for its total Mn substance and titrimetry for its total Fe substance. Collecting of meteorology data comprises wind direction, wind velocity and humidity that will be used to determination of overlay direction and distance of sampling point and also authentication of the falling dust spread to the wind direction by using the Gauss distribution formula to determine the direction and distance of spread. Results of the study showed the frequency of wind direction in 2002 tended from 180° -0°, in 2003 from 225° -0°, in 2004 from 270° -90° and in 2005 from 22,5°-45°. The average velocity ranged between 2,1 m/s -2,6 m/s in 2002-2005. From the measurement outputs it was obtained the weight of dust from each stacks that is 3,65 g/m³ from stack A; 59,66 g/m³ from stack B; 13,37 g/m³ from stack C; 91,65 g/m³ from stack D; 78,16 g/m³ from stack E; 24,56 g/m³ from stack Fand 7,59 g/m³ from stack G. By doing mathematical calculation using the Gauss distribution formula, it was obtained results that will be compared with the dust weight obtained from the above measurement. Then we got eight sampling points that needed to be considered to be altered or permanent that is number 1, 7, 40, 41, 46, 16, 2 and 6, two sampling points needed to be altered are number 8 and 47, and five sampling points that are still used are numbers 3, 42, 13, 4 and 5.