Potential of S-containing and P-containing complexones in improving phytoextraction of mercury by Trifolium repens L.

Abstract

Mercury is a global pollutant in the modern world. There is a large number of areas in the world where mercury is present in soils in significant quantities. Remediation methods which have traditionally been proposed may pose a risk of secondary mercury contamination and/or adverse health effects for cleaners. Phytoextraction of heavy metals from the soil environment is currently considered one of the promising non-invasive methods of remediation. But this approach has limited effectiveness. Chemically induced phytoextraction can increase the efficiency of this process both by converting less bioavailable mercury compounds to bioavailable fractions in the soil and by increasing the rate of transfer of metals in plants. This paper presents the results of a screening study of various chemical amendments to enhance the phytoextraction of mercury by Trifolium repens L . The results showed good potential for the induction of phytoextraction of phosphorus(P) and sulfur (S)-containing chelates. With this study, for the first time for the phytoextraction of mercury, the monoethanolamine salt of 2,2′-(ethylenedithio) diacetic acid was used as the S-containing chelate, and the disubstituted potassium salt of 1-hydroxy ethylidene-1,1-diphosphonic acid was used as the P-containing chelate. Further attention is given to study the effect that exogenous application of phytohormones and plant growth regulators has on the efficiency of mercury absorption and physiological status of plants, which performed well in combination with a P-containing chelate.

Effect of monoethanolamine salt-containing dicarboxylic acid and plant growth regulators on the absorption and accumulation of mercury

“…Such schemes have great potential for practical applications. The increasing effect of the chelating agent by treatment with GA and IAA was also recorded in relation to other inducers: EDTA with phytoextraction of lead using corn ( Zea mays L.) and HEDP for the phytoextraction of mercury ( Hadi et al, 2010 ), cadmium, copper, and nickel ( Makarova et al, 2021a , 2021b) with T. repens. These data corroborate with the results obtained using the induction scheme [thiosulfate + PGRs (GA/IAA/Fe-EDDHA)], although complexones of different classes were used (polyaminopolycarboxylic and phosphonic acids).…”

“…T. repens was used in experiments in the first stage ( Makarova et al, 2021a ). The positive qualities of T. repens in this study are winter resilience hardiness for the Russian climate and ability to produce sufficient biomass.…”

“…The coefficients of BAF and TF were estimated according to the methods described in previous studies ( Cojocaru et al, 2016 , Makarova et al, 2021a ).…”

“…A recent publication of the proposed study described a new chelating agent that represents the class of polycarboxylic acids. The monoethanolamine salt of bithiodiacetic acid, in which the sulfur atom acts as a coordination partner for mercury, creates a high selectivity of interaction ( Makarova et al, 2021a ). According to data obtained using meadow clover ( Trifolium repens L.), the coefficient of biological accumulation (the concentration of the test substance in/on the test organism referred to the concentration of the test substance in the environment) with the addition of monoethanolamine salt of 2,2′-(ethylenedithio) diacetic acid (MEDBA) was higher than that of EDTA and sodium thiosulfate.…”

Adição de fito-hormônio e de bactéria promotora de crescimento em sistemas alagados construídos tratando águas contaminadas com cromo

“…Em contraste, o uso de BPCV e fito-hormônio isolado ou associado nos sistemas SACF+B, SACF e SACB minimizaram os danos visuais. De acordo comMakarova et al, (2021), o uso de fito-hormônio aumenta a eficácia dos sistemas antioxidantes das plantas, ajudando a reduzir o estresse metabólico causado pela presença de metais pesados. JáCaires et al (2021), afirmam que o uso de bactérias promove o crescimento de plantas e aumenta a produção de fito-hormônios, resultando em alongamento radicular e maior aquisição de nutrientes e água(CAIRES et al, 2021).5.2.2.…”