Changes in the Lower Drava River Water Quality Parameters Over 24 Years

Abstract

The goal of this study was to analyse 13 physico-chemical and microbiological parameters of the Drava River water at three sampling sites in the lower Drava region (eastern Croatia) over two distinct periods: the pre-war period between 1985 and 1992 and the post-war period between 1993 and 2008. Over both periods, most parameters kept within the tolerable water quality limits, while NO 3 -N, NH 4 -N and BOD 5 were higher. The lower Drava showed slight organic pollution with high concentrations of dissolved oxygen. High levels of total coliforms and heterotrophic bacteria in the post-war period were only found downstream of the town of Osijek. Upstream of Osijek, the river showed a tendency for improvement.

Trend Analysis of Water Quality Parameters in the Middle Part of the Danube Flow in Serbia

“…Right side tributaries also have to be taken into consideration. According to Gvozdic et al [37], the lower Drava River showed slight organic pollution downstream of the city Osijek. Persic et al [38] are reporting only moderate signs of distortion, as a result of anthropogenic activities in watercourses draining the forested catchment of the Spacva River basin.…”

Impact assessment of mine drainage water and municipal wastewater on the surface water in the vicinity of Bor

“…Amonijum jon nije toksičan za žive organizme. Međutim, opasnost za živi svet postoji u slučaju većih vrednosti pH (iznad 9) kada je dominantan NH 3 kao toksična komponenta [12,13].…”

Evaluation of significantly modified water bodies in Vojvodina by using multivariate statistical techniques

“…Povećane vrednosti su uglavnom posledica ispuš-tanja komunalnih i industrijskih otpadnih voda i primena nitratnh đubriva. Nezagađene vode uglavnom sadrže manje od 0,1 mg NH 4 -N, a veće vrednosti mogu da budu posledica ispuštanja komunalnih otpadnih voda [17,18].…”

“…Temperatura može uticati na hemijske i biološke procese i samim tim na uslove života akvatičnih organizama. Na osnovu navedenih podataka može se zaključiti da su temperature vode na mernim stanicama uslovljene sezonskim varijacijama [17][18][19].…”