**Acknowledgements**

method were efficient and a quantity of 0.7 mg of alloyed (Ni, Cr and Mn was majority) metals was obtained. For a selective recovery of heavy metals is necessary that the electrochemical process should be conducted according to the differences of deposition potential of each metal

The balance of phytoremediation and heavy metal extraction indicated that the thermal treatment followed by ash leaching and electrolysis was an efficient method of metal extraction from the phytoremediation by-products – the plant biomass. By this process could be recov‐ ered saleable heavy metals and the waste resulted from phytoremediation was a heavy metal

For the studied area, in the vicinity of metallurgical plant of Targoviste city, the heavy metal concentration in soil for Cu, Sn, Pb and Mn exceeded the alert threshold for agricultural soil. For Zn, Ni and Cr, some of the results showed values that exceeded also the alert threshold

The metal concentration in soil was according with the position against the pollution source. The heavy metal concentration was widely different in the seven studied species of perennial grasses, and the bioaccumulation capacity was different according with the species and metal concentration in soil. Even a species accumulate high concentrations of metals, this could be because of the high content of metal in soil, not because the species showed accumulative

**Metal Maximal concentration in studied species (mg/kg) Maximal value of bioaccumulation factor**

**Table 8.** The maximal values of heavy metal concentration and bioaccumulation factor for studied plant species

The thermal treatment of plant biomass was an effective method for metal concentration in

**Cu** 113,83 *Festuca pratensis* 1,12 *Cynodon dactylon* **Zn** 921,67 *Lolium perenne* 1,36 *Cynodon dactylon* **Sn** 379,23 *Festuca pratensis* 6,06 *Cynodon dactylon* **Pb** 66,30 *Lolium perenne* 12,29 *Luzula campestris* **Co** 4,6 *Agrostis tenuis* 0,40 *Agrostis tenuis* **Ni** 60,23 *Agrostis alba* 1,63 *Agrostis alba* **Mn** 703,93 *Lolium perenne* 0,33 *Lolium perenne* **Cr** 191,99 *Stipa capillata* 2,67 *Agrostis alba* **Mo** 25,63 *Festuca pratensis* 15,34 *Cynodon dactylon*

[42, 43].

**8. Conclusions**

for industrial soils.

capacity – BF higher than 1 (Table 8).

the material which will be used in metal recovery.

low-concentration material, without toxicity risk.

330 Environmental Risk Assessment of Soil Contamination

The research is part of the PhD thesis "Studies and research concerning the remediation of heavy metal polluted soil by eco-technological procedure", in Romanian, realized by the author in 2011. Is a good opportunity to thank my colleagues Adrian Catangiu for his involve‐ ment in the experiment of metal recovery by electrolysis and Irina Fierascu and Radu Claudiu Fierascu for their involvement in the sample analyses by ICP-AES and EDXRF. Also I want to thank my thesis coordinator, Prof. Georghe Ionita for his support.
