Comparative Phytoremediation of Chromium‐Contaminated Soils by Fenugreek, Spinach, and Raya

Abstract

A glasshouse investigation was undertaken to evaluate the natural potential of fenugreek (Trigonella foenumgraecum L.), spinach (Spinacia oleracea L.), and raya (Brassica campestris L.) for cleanup of chromium (Cr)-contaminated silty loam and sandy soils. Four kilograms of soil per treatment in earthen pots was treated with five levels of chromium [0, 1.25, 2.5, 5.0, and 10.0 mg Cr kg 21 soil through dipotassium chromate (K 2 Cr 2 O 7 ], equilibrated for 21 days at field-capacity moisture content, and then fenugreek, spinach, and raya were grown for 60 days after seeding. The concentration of diethylene triamine pentaacetic acid (DTPA)-extractable Cr increased significantly with increasing rate of Cr application in both soils, but the increase was higher in sandy soil than in silty loam soil. The DTPA-extractable Cr in both soils decreased after harvesting of crops compared to its concentration in soil before sowing of the crops. The decrease in DTPA-extractable Cr concentration was highest in soil growing raya and least in the fenugreek-growing soil. The percent reduction in dry-matter yield (DMY) with increasing levels of added Cr in comparison to the zero-Cr control was highest for fenugreek (49 and 52%) followed by spinach (36 and 42%) and lowest for raya (29 and 34%) in silty loam soil and sandy soil, respectively. Also, the percent reduction in mean shoot yield of all crops was higher in sandy soil (41%) compared to silty loam soil (36%), when the rate of applied Cr was increased from 0 to 10 mg Cr kg 21 soil. The DMY of both shoot and root was highest for raya and lowest for fenugreek. The Cr concentration in fenugreek, spinach, and raya increased with increasing level of added Cr in both soils. The concentration of Cr in both shoot and root was highest in raya, followed by spinach and fenugreek. The overall mean uptake of Cr in shoot was almost four times and in root was about two times higher in raya compared to fenugreek. The findings indicated that family Cruciferae (raya) was most tolerant to Cr toxicity, followed by chenopodiacea (spinach) and Leguminosae (fenugreek). Because raya removed the highest amount of Cr from soil, it could be used for pytoremediation of mildly Cr-contaminated soils.

How Soil Nutrient Availability Influences Plant Biomass and How Biomass Stimulation Alleviates Heavy Metal Toxicity in Soils: The Cases of Nutrient Use Efficient Genotypes and Phytoremediators, Respectively

“…Under these conditions, plant growth and biomass are negatively affected [17][18][19][20]. According to Caldelas et al (2012) [19], not only growth inhibition happened, but also root to shoot dry matter partitioning (R/S) modified (increased 80%) at Cr toxic conditions in Iris pseudacorus L. plants.…”

“…Phytoremediation is an emerging technology and is considered for remediation of inorganic-and organic-contaminated sites because of its cost-effectiveness, aesthetic advantages, and long-term applicability. This technique involves the use of the ability of some plant species to absorb and accumulate high concentrations of heavy metal ions [17]. Some of these species may be a few ones from Brassicaceae family, such as raya (Brassica campestris L.) [17] and Thlaspi caerulescens [23], or from other families, such as spinach (Spinacia oleracea L.) [17], Sedum plumbizincicola [24], Amaranthus hypochondriacus [25], Eremochloa ophiuroides [26], Iris pseudacorus L. [19], Ricinus communis L., plant of Euphorbiaceae family [18].…”

Chromium Uptake Efficiency of <i>Spinacea olaracea</i> from Contaminated Soil

“…From the above result it is also concluded that metal accumulation is higher in roots as compare to shoots. On the contrary, Dheri et al (2007) reported maximum removal of hexavalent chromium 42% through spinach 72 (Spinacea olaracea). The chromium uptake by plants has been found to be positively correlated to chromium application by many workers (Cervantes et al, 2001;Babalola et al, 2008;Singaram, 1994;Singh, 2001;Jain et al, 2000;Negi et al, 2007;Karunyal et al, 1994).…”

“…From the above result it is also concluded that metal accumulation is higher in roots as compare to shoots. On the contrary, Dheri et al (2007) reported maximum removal of hexavalent chromium 42% through spinach …”

Degradation of Total Petroleum Hydrocarbon (TPH) in Contaminated Soil Using <i>Bacillus pumilus</i> MVSV3

“…Earlier investigations were reported on growth of fenugreek on chromium-contaminated soil Dheri et al, 2007 . Agriculture soil was sterilized before the experiments to ensure no interference from other microorganisms Anuradha et al, 2014 .…”