Analysis of Chemical Parameters in Water Pollution Using the Winkler Titration

Abstract

An experiment titled “Water Pollution” was conducted to identifyindicators of water pollution, determine the chemical parameters contributing towater contamination, and calculate the pollution index. The methods used in thisexperiment were both qualitative and quantitative, involving the Winkler Titration technique and the calculation of Biochemical Oxygen Demand (BOD) values. A seawater sample was treated with MnSO₄, NaOH, and KI, forming a white precipitate. After standing, H₂SO₄ and a basic indicator were added, producing a pinkish-red color. The solution was then titrated with Na₂S₂O₃ until it became clear (at 15 ml), and the BOD value was calculated. The resultsobtained were DOi = 1.73 mg/L, DO₅ = 0.14 mg/L, and BOD = 1.59 mg/l. This experiment provides insight into the causes and chemical parameters responsible for water pollution.