Evaluation of Suitability of Amaranthus Caudatus L. and Ricinus Communis L. in Phytoextraction of Cadmium and Lead from Contaminated Substrates

Abstract

Abstract:The phytoextraction is a process that uses living plants for cleaning up the heavy metals from contaminated soil. The cadmium and lead contamination of soils results from the application of sludge or urban composts, fertilizers, pesticides, motorization, metallurgy, and different technological processes. In industrial terrain the content of cadmium and lead in soils has increased in the recent years. This study was undertaken to evaluate the potential of Amaranthus caudatus L. 'Atropurpureus' and Ricinus communis L. 'Sanguineus Apache' for phytoextraction of cadmium and lead. Two species of ornament plants, i.e. Amaranthus caudatus L. 'Atropurpureus' and Ricinus communis L. 'Sanguineus Apache', were planted in drainless containers in a substrate artifi cially polluted with cadmium and lead in order to evaluate their suitability for phytoremediation of soils or substrates contaminated with these metals. Cadmium was applied at increasing rates of 0, 1, 5 and 10 mg in the form of cadmium sulfate 3CdSO 4 •8H 2 O, while lead was used at 0, 100, 500 and 1000 mg Pb•dm -3 in the form of lead acetate (CH 3 COO) 2 Pb•3H 2 O. The applied doses of cadmium and lead in the experiment refl ected different degrees of soil pollution. After fi ve months of growth it was found that Amaranthus caudatus L. accumulated the biggest concentrations of cadmium and lead in leaves and the lowest concentrations in infl orescences. Ricinus communis L. accumulated the highest concentrations of cadmium in stems, while the lowest concentrations in infl orescences, whereas the biggest concentration of lead was accumulated in infl orescences and the least lead was accumulated in leaves. The biggest reduction of cadmium and lead concentrations after the completion of the experiment was found in substrates, in which Amaranthus caudatus L. was grown. The tested species of ornamental plants may be used in the phytoextraction of cadmium and lead from soils contaminated.

Ricinus communis L. (Castor bean), a potential multi-purpose environmental crop for improved and integrated phytoremediation

“…Castor bean (R. communis, Euphorbiaceae) is a fast-growing, perennial shrub, with a well-developed root system, tolerance to poor soil fertility, high economic and biomass value. These traits make castor bean a candidate species for phytoremediation (16)(17)(18)(19).…”

“…Castor bean has the potential to tolerate and accumulate heavy metals like Cd (13,14 ), As (67,88), Ni (68,89,99), Zn (100), and Cu (70,77) and high tolerance to Cd, Cu and Zn (90). R. communis is a good candidate for the removal of DDTs (dichloro diphenyl trichloroethane) and Cd from contaminated soils (78).…”

The effect of soil risk element contamination level on the element contents in Ocimum basilicum L.

“…Sainger et al investigated the element uptake by plants growing in highly contaminated soils and reported a high adaptatability of some plant species growing in such environment. For example, Bosiacki et al (2013) observed increasing yield of Ricinus communis aboveground biomass with increasing Cd content in cultivation substrate. Clearly, plants growing at the highly contaminated sites developed a range of mechanisms that may be ivolved in the detoxifi cation of risk elements such as reduced uptake of these elements, their binding to the cell wall, immobilization, exclusion of the plasma membrane, reduction of heavy metal transport, compartmentalisation and metal chelation by tonoplast located transporters, expression of stress proteins, role of organic acids and aminoacids, etc.…”

Metabolic responses to zinc stress in Amaranthus caudatus roots and leaves

“…Amaranthus species attract a special interest in the context of Zn stress due to their importance as a source for valuable nutrient-rich foods and fodder crops (Achigan-Dako et al, 2014) with pronounced stress tolerance and well-characterized potential for HM phytoremediation (Watanabe et al, 2009;Bosiacki et al, 2013;Ko et al, 2014). From the point of primary metabolism, this genus is featured with C4 type of photosynthesis (Ludwig, 2016) and elevated production of oxalic acid (Gélinas and Seguin, 2007;Osmolovskaya et al, 2018a).…”