Stable complexes formation caused by usage of complexing agents as additive in plating solutions, made waste water treatment aggravated and expensive. The investigation results of samples that contain some cations expected in waste waters from this type of facilities, are presented in this paper. The precipitation of disolved heavy metals by neutralization, in the presence of strong chelators, do not give requested results. The dithiocarbamates are effective in complexing heavy metal ions forming insoluble compounds, with solubility far below that of the corresponding hydroxides. Inductively Coupled Plasma Optical Emission Spectroscopy is used for wastewater samples analysis. After the reduction of Cr6+ into Cr3+ ions and homogenization, dithiocarbamate is added. Modified neutralization process with unchanged retention time and pH 9.0 +/- 0.2 results the Law permitted wastewater quality.

Aquatic macrophytes are exceptional accumulations of heavy metals and they are very important in phytoremediation of the pollutants. The aim of the survey was to show according to content of heavy metals in aquatic macrophytes DTD (Danube-Tisza-Danube) canal complex, at localities under great human influence indicate the situation of chemical contamination these localities and to define test species, actually the ones that have the greatest accumulation. Plant material was prepared according to the Standard Methods for Examination of Water and Wastewater of the American Health Association. Analysis of heavy metals in the plant tissue samples was done by standard methods using atomic absorption spectrophotometry. The best accumulator of majority of heavy metals is Ceratophyllum demersum. The results show that mentioned species can be used for removal of heavy metals from water, what means that it has the ability of phytoremediation of pollutants.

Investigation in this study should indicate to importance of aquatic macrophytes in accumulation of toxic metals in aquatic ecosystems and control of their pollution, as well as to indicate which plants are well hyperaccumulators and test species for remediation, in order of protection, regeneration and conservation of the Gruza lake as reservoir that is important for water supply and as particular natural ecosystem.

The contents of heavy metals (Mn, Pb, and Cd) in water, sediments and shoots of emersed plants Phragmites communis, Typha latifolia and Typha angustifolia in the area of Bardaca fish pond were analyzed. Species Typha latifolia has shown the best ability for the bioaccumulation of heavy metals tested. Therefore, this species could be recommended as the phytoremediator of these pollutants from polluted waters. The results of this study indicate that the accumulation of tested elements in the water, and their availability to plants are still far from the critical level which may cause disturbance of balans in the Bardaca ecosystem.