Determination of Chemical Oxygen Demand (COD) Concentration in Domestic Wastewater Using UV-Vis Spectrophotometry Method Based On The Effect Of Reflux Time And Preservation Time: Penentuan Konsentrasi Chemical Oxygen Demand (COD) Dalam Air Limbah Domestik Menggunakan Metode Spektrofotometri UV-Vis Berdasarkan Pada Pengaruh Waktu Refluks Dan Waktu Pengawetan. Stannum : Jurnal Sains dan Terapan Kimia, [S. l.], v. 4, n. 1, p. 13–18, 2022. DOI: 10.33019/jstk.v4i1.2866. Disponível em: https://www.journal.ubb.ac.id/index.php/stannum/article/view/2866. Acesso em: 25 apr. 2026.