CLIMATIC AND ANTHROPOGENIC INFLUENCES ON WATER QUALITY IN LAKE BRATES, ROMANIA.

Lake Brates is located near Galati city, in the south-eastern part of Romania being one of the largest lakes in the country. Unfortunately, water quality has greatly decreased in recent years, both due to human actions and to climate change. The present paper aims at establishing the quality of the water in Lake Brates as resulted from the calculation of the water quality index (WQI) by the weighted arithmetic method. In order to calculate this index, several sampling campaigns were carried out in various points of the lake, followed by the measurement of relevant parameters: pH, conductivity, salinity, oxygen demand (DO), chemical oxygen demand (COD), biochemical oxygen consumption at 5 days (CBO5), NO2-, NO3-, N total, Cl-, SO42-, PPO43-, heavy metals (As3+, Cr3+, Cu2+, Ni2+, Zn2+). Both the individual variation of the monitored physicochemical parameters and the variation of the WQI were tracked. Moreover, a correlation of the WQI with the climatic conditions in the region (rainfall and thermal regime) was established. The determinations were made by applying the standardized methods in force in - situ and ex-situ and by using the following equipment: the UV-Vis-NIR Spectrophotometer, Thermo Scientific Vanquish Flex UHPLC system coupled with the Mass Spectrometer, Thermo Scientific Trace GC coupled with the Quadrupole Mass Spectrometer, the Total Reflection X-Ray Fluorescence (TXRF) Spectrometer and a portable multiparameter. [ABSTRACT FROM AUTHOR]