The sewage sludge from wastewater treatment plant of Iasi, a city with 300,000 inhabitants, for domestic and industrial origin, was stored in a mud pond arranged on an area of 18,920 m2. Chemical analyzes of the sludge showed that, of all the chemical elements determined, only Zn is found at pollutant level (5739 mg∙kg-1), i.e. almost 30 times more than the maximum allowable limit for Zn in soil and 45 times more than the Zn content of the soil on which the mud pond has been set. Over time, the content of Zn in the mud pond, but also from soil to which it has been placed, has become upper the normal content of the surrounding soil up to a depth of 260 cm. On the other hand, the vegetation installed on sewage sludge in the process of mineralization, composed predominantly of Phragmites, Rumex, Chenopodium, and Aster species had accumulated in roots, stems and leaves Zn quantities equivalent to 1463 mg Kg-1, 3988 mg Kg-1, 1463 mg Kg-1, respectively, 1120 mg∙Kg-1. The plants in question represents the natural means of phytoremediation, and sewage sludge as such may constitute a fertilizer material for soils in the area, on which Zn deficiency in maize has been recorded. In addition, the ash resulted from the incineration of plants loaded with zinc may constitute, in its turn, a good material for fertilizing of the soils that are deficient in zinc.
Baker A.J.M., Mc. Grath R.D., Reeves R.D., Smith J.A.C., 2000, Metal Hyperacumulator Plants: A Review of the Ecology and Physiology of a Biochemical Resource for Phytoremediation of Metal polluted Soils. Phytoremediation of Contaminated Soil and Water. Lewis Publ. Boca Raton, FL., By Terry N and Banuelas G. (Ed.), 85-107.
Baker A.J.M., Brooks R.R., 1989, Terrestrial higher plants wich hyperaccumulate metalic elements. A review of their distribution, ecology and phytochemistry, Biorecovery, 1, 81-126.
Cho-Ruk K., Kurukate J., Supprung P., Vetayasuporn S., 2006, Perennial plants in the phytoremediation of lead-contaminated soils, Biotechnology, 5, 1-4.
Dickinson N.M., Baker A.J.M., Doronila A., Laidlaw S., Reeves R.D., 2009, Phytoremediation of inorganics; realism and synergies, International Journal of Phytoremediation, 11, 97-114.
Dornescu D., Pleșa D., Petrovici P. Dorneanu V., 1972, Influence of zinc on maise on Jijia-Bahlui Depression chernozem, Analele ICCPT Fundulea, seria B, 231-245 (in Romanian)
Greger M., 1999, Metal availability and bioconcentration in plants, in Heavy Metal Stress in Plants (Ed. Prasad M.N.V. and Hagemeyer J.) Springer, Heidelberg.
Lăcătușu R., Rizea N., Lazăr R., Kovacsovics B., Matei M.G., Matei S., Lungu M., Preda M., Claciu I., 2005, Level II Environmental Balance and Risk Assessment required for the clearance of sludge storage Tomești, ICPA Bucharest Archive (In Romanian).
Lăcătușu R., Lăcătușu A.-R., Stanciu-Burileanu M.M., Lazăr D.R., Lungu M., Rizea N., Catrina V., 2012, Phytoremediation of a sludge depozit proceeded from a city wastewater treatment plant, Carpathian Journal of Earth and Environmental Sciences, 7, 1, 71-79.
Marinciuc Irina Elena, Catrina Virginia, Lăcătușu R., Lazăr Rodica, Topală Daniela, 2010, Research regarding the phyto-rehabilitation of the sludge storage area from wastewater treatment plants, An. Știin. Univ. “Al. I. Cuza” Iași, Geologie, Tomul LVI, 2, 75-81.
Malski D., Roman C., Miclean M., Șenilă M., Ștefănescu L., Malsch-Florian B., Bolonyi A., Ghira G., Brăhaița D., Cuhan A., 2013, Phytoextraction of heavy metals from industrially polluted zone using Lolium perenne and Lemna minor, Environmental Engeneering and Management Journal 12,5, 1103-1108
Park W., Ahn S.J., 2014, How do heavy metal ATPase contribute to hyperaccumulation?, J. Plant Nutr. Soil Sci., 177, 121-127.
Pollard A.J. Reeves R.D., Baker A.J.M., 2014, Facultative hyperracumulation of heavy metals and metalloids, Plant Science, 217-218, 8-17.