Investigation of the Pollution from Bilge Water in Van Lake

Abstract

In this study, the water pollution caused by the bilge waters of the ships operating in Lake Van was investigated. While the water temperature (WT), pH, dissolved oxygen (DO), oxygen saturation (OS), electrical conductivity (EC) and salinity parameters were measured in ten different stations where the ships are sheltered, chemical oxygen demand (COD) and oil-grease analyses were carried out in the lake water and bilge waters taken from the ships. The lowest and highest COD values were 32 and 240 mg/L, respectively, and the lowest and highest oil-grease values were 23 and 146.5 mg/L, respectively. In the bilge waters, the lowest and highest COD values were 22 and 5 890 mg/L, respectively, and the lowest and highest oil-grease values were 11.3 and 10 000 mg/L, respectively. According to Water Pollution Control Regulation, WT, in general, is I-II. class, DO I. class, OS I. class and pH IV due to the alkaline lake water. However, the mean COD and oil-grease values in the lake sample waters are IV. class. The oil-grease values in all ships were above the limit value (15 mg/L) according to MARPOL 73/78. As a result of the water quality analysis, it was determined that the areas used by the ships as shelters in Van Lake were adversely affected by the bilge waters released by the ships.