THE USE OF HEAVY METAL ACCUMULATING PLANTS FOR DETOXICATION OF CHEMICALLY POLLUTED SoILS

ANTONKIEWICZ, J., JASIEWICZ, Cz., RYANT, p.: The use of heavy metal accumulating plants for detoxication of chemically polluted soils. Acta univ. agric. et silvic. Mendel. Brun., 2004, LII, No. 1, pp. 113-120 The studies conducted from 1997 to 1999 in a vegetation hall were performed as a pot experiment on ordinary silt soil. Jerusalem artichoke, maize, Sida hermaphrodita rusby, amaranth and hemp were used as indicator plants. The results confirmed, great diversification of the element contents which depends not only on the species but also on the part of individual plants. Analysis of the data revealed also another dependence: increased concentration of heavy metals in the soil corresponded to a higher content of heavy metals in the plants. Significant differences in this respect were observed for the plant species grown in unpolluted or differently contaminated soil. detoxication, heavy metals, plants, polluted soils, Helianthus tuberosus L., Zea mays L., Sida hermaphrodita Rusby, Amaranthus L., Cannabis sativa L., Jerusalem artichoke, maize, amaranth, hemp Ročník LII 11 Číslo 1, 2004 113 Industrial activities cause a fast and considerable degradation of soil and vegetation cover, which necessitates seeking for suitable methods of management to restore industrial lands. On a chemically polluted soil vegetation may play an important ecological and sanitary role. Proper management of such areas including selection of plants to grow may significantly contribute to recovery of soil (SIUTA, 1995). Numerous efforts have been undertaken recently to remove heavy metals from soils, among others through phytoremediation (JASIEWICZ and ANTONKIEWICZ, 1999, KUCHARSKI et al., 1998, SAS-NOWOSIELSKA, 1999). Plants revealing high capability for heavy metal accumulation have been also sought (GAMBUś, 1997b, JASIEWICZ and ANTONKIEWICZ, 2000ab). The selection of plant species resistant to enhanced concentration of heavy metals and accumulating high amounts of them could support reclamation of the contaminated areas (KUCHARSKI et al., 1999). Among species with enhanced tolerance to heavy metals in soil belong Sida hermaphrodita rusby, amaranth, Jerusalem artichoke and fibre plants: hemp and linseed (NALBORCZYK, 1995, GRzEBISz et al., 1998ab, BORKOWSKA and STyK, 1997, JASIEWICZ and ANTONKIEIWCZ, 1999). The aim of the investigation was to determine the effect of the soil pollution with heavy metals (Cd, Pb, Ni, Cu and Zn) on the yield of studied plants species and accumulation of heavy metals in plant biomass. MATERIALS AND METHODS The studies were conducted in 1997-1999 as pot experiments in a vegetation hall. An ordinary silt soil with cation exchange capacity (CEC) 811 mmol (+) · kg–1, pHKCl = 6.0 and organic C content 9.5% was used. Heavy metal contents determined in 65% solution of HNO3 and 70% HClO4 were as follows: 1.2 mg Cd, 54.3 mg Pb, 5.0 mg Ni, 13.8 mg Cu and 226.6 mg Zn· kg –1soil d.w. The experimental design 114 J. Antonkiewicz, cz. Jasiewicz, P. ryant comprised the following 8 treatments (each in 4 replications): control without heavy metal addition and 7 treatments with increasing doses of heavy metals (tab. I). The heavy metals were applied as water solutions of the following salts: 3CdSO4 · 8H2O, CuSO4· 5H2O, NiSO4 · 7H2O, Pb(NO3)2 and ZnSO4· 7H2o. All pots received the same basic fertilisation with: 0.3 g N as NH4No3; 0.08g P in KH2po4; 0.20 g K in KH2po4 + KCl and 0.05g MgSO4 · 7H2O per 1 kg of soil d.w. The heavy metals and fertilisers were mixed with the soil one week prior to the seed sowing. Jerusalem artichoke, maize, Sida hermaphrodita rusby, amaranth and hemp were the indicator plants. Vegetation periods for individual plants were diversified and the average duration in three years experiments was: for Jerusalem artichoke, maize, Sida, amaranth and hemp: 127, 99, 153, 88 and 99 days, respectively. During the vegetation period the plants were watered with redistilled water and soil moisture maintained at 60% of maximum water holding capacity. The plants were harvested at full ripeness. They were dried at 75oC and then the aerial parts yield amount was determined by weighting. The contents of Cd, Pb, Ni, Cu and Zn were determined after dry incineration with flame technique in a Philips PU 9100 X atomic absorption spectrophotometer (AAS) (OSTROWSKA et al., 1991). I: experimental design Treatments Doses of metals mg . kg-1 d.w. soil