http://dx.doi.org/10.20884/1.oa.2022.18.S1.979 Analysis of Sulfate (SO 4 ) Concentration in Bittern as Raw Material for Magnesium Sulfate (MgSO 4 ) Uswatun Hasanah, Nike I. Nuzula * , Ashari Wicaksono, Makhfud Efendy, Wiwit S. W. Pratiwi Department of Marine Science, Trunojoyo University of Madura, Bangkalan, Indonesia *Corresponding author: nike.nuzula@trunojoyo.ac.id Received 9 November 2021; Accepted 24 February 2022; Available online 18 April 2022 ABSTRACT The investigation on traditional salt production had developed in the characterization of Bittern. Bittern is the dense residual liquor with specific gravity ≥ 1.28 gr/cm 3 obtained after precipitation and harvesting of NaCl salt from seawater. In this research, the measurment of sulfate in the bittern was carried out. Sulfate is one of the raw materials for MgSO 4 . The determination of sulfate concentration is using a turbidimetric method according to SNI 6989 20:2009 using a spectrophotometer at a wavelength of 420 nm. In this process the Sulfate in an acidic environment reacts with barium chloride (BaCl2) to form barium sulfate (BaSO4) crystals. The light absorbed by the barium sulfate suspension is measured with a photometer and the sulfate content is calculated by comparing the readings with the calibration curve. The results of the analysis showed that at 31 o Baume the sulfate content is 40.0 g/L, at 32 o Baume the sulfate content is 42.6 g/L, at 33 o Baume the sulfate content is 42.8 g/L. The sulfate concentration in the bittern showed a linear increase with increasing water concentration. The sulphate content of bittern with 31 o Be levels has an average value of 40.028 g/L, at 32 o Be levels the average sulphate content is 42.599 g/L and at 33 o Be levels it is 42,825 g/L. Keywords: Bittern, Sulfate, o Be ABSTRAK Investigasi produksi garam tradisional telah berkembang dalam karakterisasi Bittern. Bittern adalah cairan residu padat dengan berat jenis 1,28 gr/cm3 yang diperoleh setelah pengendapan dan pemanenan garam NaCl dari air laut. Pada penelitian ini dilakukan identifikasi konsentrasi sulfat pada bittern. Sulfat merupakan salah satu bahan baku MgSO 4 . Perhitungan konsentrasi sulfat dilakukan dengan menggunakan metode turbidimetri menurut SNI 6989 20:2009, yakni menggunakan spektrofotometer pada panjang gelombang 420 nm. Pada proses ini Sulfat dalam suasana asam bereaksi dengan barium klorida (BaCl 2 ) membentuk kristal barium sulfat (BaSO 4 ). Cahaya yang diserap oleh suspensi barium sulfat diukur dengan fotometer dan kandungan sulfat dihitung dengan membandingkan pembacaan dengan kurva kalibrasi. Hasil analisis menunjukkan bahwa pada 31 o Be kandungan sulfatnya 40,0 g/L, pada 32 o Be kandungan sulfatnya 42,6 g/L, pada 33 o Be kandungan sulfatnya 42,8 g/L. Konsentrasi sulfat dalam bittern menunjukkan peningkatan linier dengan meningkatnya konsentrasi air. Kadar sulfat pahit dengan kadar 31 o Be memiliki nilai rata-rata sebesar 40,028 g/L, pada kadar 32 o Be kadar sulfat rata-rata adalah 42,599 g/L dan pada kadar 33 o Be sebesar 42.825 g/L. Kata kunci: Bittern, Sulfate, Kadar Be 1. Introduction Bittern is a residual product from the production of salt, conventionally referred as old water. It has a form of a yellowish liquid, placed on the crystallization table and does not settle during the evaporation process. Bittern has a special parameter in the form of concertation levels, which is called o Be. Generally, the o Be of seawater is 26 o Be - 29 o Be. Mustafa and Abdullah (2013) stated that Bittern is a solid residue liquid having a specific gravity of 1.28 gm/cm3. In addition, the bittern has a lot of mineral content that does not crystallize in the salt table which makes it a saturated solution Omni-Akuatika Special Issue The 4 th KRIPIK-SciFiMaS 2022: 47 - 52 ISSN: 1858-3873 print / 2476-9347 online Research Article journal homepage: http://ojs.omniakuatika.net