Aim of this study was to assess quality of the Danube sediment from the water source "Ratno Ostrvo", which is in the vinicity of the Oil Refinery "Novi Sad" (Serbia, Yugoslavia), after bombardment of the refinery in 1999. In the period March-October 2000, sediment samples were analysed for their oil and oil-derivates contents, i.e. mineral oils contents, by quantitative IR-spectrophotometry, and by qualitative and quantitative GC/MS analyses for their polycyclic aromatic hydrocarbons (PAH) contents. Oil pollution was detected in sediment samples.

Drainage of industrial and communal effluents, directly into the water flow, as many hydrotechnical activities, significantly influence the schedule and balance of the processes that take place into water. In this paper, there are represented the results of systematic control of the water quality of the Danube river and DTD (Danube-Tisza-Danube) channel on the parts Vrbas-Bezdan and Becej-Bogojevo, at the control station network of the Republic Weather Bureau (the Republic of Serbia), for the period of 1991-1996. The results show that the most adverse influence of anthropogenic factor is on the part of the flow of the DTD (Danube-Tisza-Danube) channel from Vrbas to the flow into Tisza river.

Nowadays, different profile of experts are present opinion that surface water quality are exchanged. Type and degree of mineralization content exchange are shown by argumentation. The work have carried out taking into consideration suitability of Danube water for irrigation. The results of chemical investigation from three sample locations (Bezdan, Novi Sad and Banatska Palanka), Serbia (Yugoslavia) during the period 1981-1995, were analyzed. The main statistical parameters and tests of homogeneity are used during the work. Results have pointed put more or less concentration decreasing of analyzed parameters. From statistical point of view, exchange of electrical conductivity and potassium are prominent on all three localities.

The results of long standing and systematic monitoring of quality of river Danube's water, done by the net of stations for controllingquality of water of the Republic Hydrometeorological Service of Serbia (Yugoslavia) are given in this paper. The amount of organic matter (HPK, BPK5), concentration of dissolved oxygen, nutritive matters (NH4(+), NO2(-), NO3(-) and total PO4(3-) and conductivity are specially examined. The results are shown depending on seasonal measuring (average values for spring, summer, autumn and winter) during the period 1995-1998, and the changes are analyzed.

Application of passive samplers is demonstrated for assessment of temporal and spatial trends of dissolved polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and priority metals in the middle stretch of the Danube river. Free dissolved concentrations of PAHs, measured using SPMD samplers, ranged from 5 to 72 ng L−1. Dissolved PCBs in water were very low and they ranged from 5 to 16 pg L−1. Concentration of mercury, cadmium, lead and nickel, measured using DGT samplers, were relatively constant along the monitored Danube stretch and in the range <0.1, <1–20, 18–74, and 173–544 ng L−1, respectively. Concentrations of PAHs decreased with increasing temperature, which reflects the seasonality in emissions to water. This has an implication for the design of future monitoring programs aimed at assessment of long term trends. For such analysis time series should be constructed of data from samples collected always in the same season of the year.

Surface waters are becoming increasingly contaminated by pharmaceutically active compounds (PhACs), which is a potential risk factor for drinking water quality owing to incomplete riverbank filtration. This study examined the efficiency of riverbank filtration with regard to 111 PhACs in a highly urbanized section of the river Danube. One hundred seven samples from the Danube were compared to 90 water samples from relevant drinking water abstraction wells (DWAW) during five sampling periods. The presence of 52 PhACs was detected in the Danube, the quantification of 19 agents in this section of the river was without any precedent, and 10 PhACs were present in >80% of the samples. The most frequent PhACs showed higher concentrations in winter than in summer. In the DWAWs, 32 PhACs were quantified. For the majority of PhACs, the bank filtration efficiency was >95%, and not influenced by concentrations measured in the river. For carbamazepine lidocaine, tramadol, and lamotrigine, low (<50%) filtration efficiency was observed; however, no correlations were observed between the concentrations detected in the Danube and in the wells. These frequently occurring PhACs in surface waters have a relatively even distribution, and their sporadic appearance in wells is a function of both space and time, which may be caused by the constantly changing environment and micro-biological parameters, the dynamic operating schedule of abstraction wells, and the resulting sudden changes in flow rates. Due to the changes in the efficiency of riverbank filtration in space and time, predicting the occurrence and concentrations of these four PhACs poses a further challenge to ensuring a safe drinking water supply.

The paper presents the results of preliminary study of the intestinal content in bream (Abramis brama L. 1758) of the Danube River through the Belgrade Region. The fishes were collected in May and October during the period 2007-2009 at two sampling sites along the course. A total of 42 fish specimens of different age (2+ to 6+) were examined. By examination of compositing of intestine of bream have been found members from macrozoobentho-groups – Oligochaeta, Gastropoda (Lithoglyphus naticoides), Bivalvia, Amphipoda (Gamaridae). Our investigation showed that the diet of bream is dependent of bottom fauna composition and structure.

This paper presents the results of the Danube River water quality analysis based on the calculated SWQI index values, using the data set provided by the Hydrometeorological service of the Republic of Serbia for the year 2009. The relevant parameters are sampled once a month on average, at 16, measuring stations of the River Danube along the flow through Serbia. Data grouped on the sampling site basis, averaged on a yearly level, resulting in a median SWQI for each sampling station, are employed to obtain a synthesized quality indicator. Research shows that the overall quality of the water of the Danube in Serbia, SWQI = 85 for the given one-year period and to match the descriptive indicator very good water quality.

This paper presents the most important results on water quality investigation of the Danube river in the Iron Gate reservoir. The investigations are conducted by the Institute Jaroslav Cerni by means of regular monitoring renewed after a long pause in 2001. The determined phenomena are considered in regard to water quality of the Danube river in the upstream zone.

This paper provides an assessment of the Mlava River on the Danube River sediment quality. The contents of Zn, Cu, Pb, Cr, Ni, Cd and As were detected in the surface sediment. Based on the obtained concentrations of these seven metals sediment quality pollution category was determined with respect to PLI (pollution load index) and I geo (geo-accumulation index). It is found that M4 site, according to PLI and I geo (As and Cd) values can be classified as very highly polluted.