In this paper we have pointed out the hydrogeological condition in the catchment area of the Jablanica river in the south Serbia (Yugoslavia). The two units are separately presented here. The first one is mountainous part of the catchment area upstream of the gaging station of Lebane and the second one is the part of the terrain in the plain down stream to the river mounth near Pecenjevac. The hydrogeological characteristics of the two mentioned regions are given to explain the reasons of existing the constant flow of the Jablanica to Lebane and its disappearing course in the period of recession in the plain downstream. The quality of water in the Jablanica river at Lebane is good. Down stream of this gaging station the waste water collector flows into the river. In the part of recession period the ratio between them is unfavourable. We have also discussed the quality of water at the gaging station of Pecenjevac and pointed out the function of sandy-gravel deposits in the process of natural purification of the Jablanica flow.

Removal of natural organic matter (NOM) from groundwater by aluminium sulphate and polyaluminium chloride (PACl) was investigated. The maximal decrease of UV absorbance at 254 nm was near 70%. Decrease of permanganate value about 50% was achieved by PACl coagulation. Similar effect can be achieved using 2.5 fold higher concentration of aluminium sulphate. Coagulation process at pH 5.5 was successful with 3-5 times less concentration of coagulant. The heterogenous composition of NOM in water had been changing by coagulation. The total trihalomethane formation potential is 50-60% lower in coagulated water. The greatest removal was success for chloroform precursors.

In our previous papers, it is concluded that wood sawdust can be applied as adsorbent for heavy metals removing from water. All earlier investigations are done in batches, while it is confirmed that different heavy metals are adsorbing with various efficacy on sawdust of different kind of wood. Adsorption of copper ions from model water is investigated in this paper, by its passing throw column filled with poplar and fir sawdust, granulation in the range 0.5-1 mm. Starting concentration of copper ions was the same in all experiments, and flowrates of model water and column geometry are varied. Certain volumes of water are taken on the column outlet, and copper ions concentration are determinated in this samples. On the basis of these results breakthrough curves are obtained, and adsorption parameters in dynamic conditions are determinated.

Removal of natural organic matter from water was investigated using granulated activated carbon. Groundwater from northern Banat region (Serbia, Yugoslavia) was used. Samples of raw water and water after coagulation were ozonated and than GAC adsorption was performed. The investigation was carried out under the static conditions to determine the GAC adsorption capacity and kinetic coefficients.