Phytoremediation Of Co-contaminated Soil Research Articles

Ricinus communis L. (castor bean) as a potential candidate for revegetating industrial waste contaminated sites in peri-urban Greater Hyderabad: remarks on seed oil.

Ricinus communis L. (castor bean or castor oil plant) was found growing on metal-contaminated sites (4) of peri-urban Greater Hyderabad comprises of erstwhile industrial areas viz Bollaram, Patancheru, Bharatnagar, and Kattedan industrial areas. During 2013-2017, about 60 research papers have appeared focusing the role of castor bean in phytoremediation of co-contaminated soils, co-generation of biomaterials, and environmental cleanup, as bioenergy crop and sustainable development. The present study is focused on its use as a multipurpose phytoremediation crop for phytostabilization and revegetation of waste disposed peri-urban contaminated soils. To determine the plant tolerance level, metal accumulation, chlorophyll, protein, proline, lipid peroxidation, oil content, and soil properties were characterized. It was noticed that the castor plant and soils have high concentration of metals such as cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn), and zinc (Zn). The soils have high phosphorous (P), adequate nitrogen (N), and low concentration of potassium (K). Iron (Fe) concentrations ranged from1672±50.91 to 2166±155.78mgkg-1 in the soil. The trend of metal accumulation Fe>Zn>Mn>Pb>Cd was found in different plant parts at polluted sites. The translocation of Cd and Pb showed values more than one in industrial areas viz Bollaram, Kattedan, and Bharatnagar indicating the plants resistance to metal toxicity. Chlorophyll and protein content reduced while proline and malondialdehyde increased due to its tolerance level under metal exposure. The content of ricinoleic acid was higher, and the fatty acids composition of polluted areas was almost similar to that of the control area. Thus, R. communis L. can be employed for reclamation of heavy metal contaminated soils.

Phyto-enhanced remediation of soil co-contaminated with lead and diesel fuel using biowaste and Dracaena reflexa: A laboratory study

In phytoremediation of co-contaminated soil, the simultaneous and efficient remediation of multiple pollutants is a major challenge rather than the removal of pollutants. A laboratory-scale experiment was conducted to investigate the effect of 5% addition of each of three different organic waste amendments (tea leaves, soy cake, and potato skin) to enhance the phytoaccumulation of lead (60 mg kg(-1)) and diesel fuel (25,000 mg kg(-1)) in co-contaminated soil by Dracaena reflexa Lam for a period of 180 day. The highest rate of oil degradation was recorded in co-contaminated soil planted with D. reflexa and amended with soy cake (75%), followed by potato skin (52.8%) and tea leaves (50.6%). Although plants did not accumulate hydrocarbon from the contaminated soil, significant bioaccumulation of lead in the roots and stems of D. reflexa was observed. At the end of 180 days, 16.7 and 9.8 mg kg(-1) of lead in the stems and roots of D. reflexa were recorded, respectively, for the treatment with tea leaves. These findings demonstrate the potential of organic waste amendments in enhancing phytoremediation of oil and bioaccumulation of lead.

Dynamics Phytoremediation of Zn and Diesel Fuel in Co-contaminated Soil using Biowastes

In phytoremediation of co-contaminated soil, developing strategies is a major challenge for simultaneous and efficient remediation of multiple pollutants. A lab-scale experiment was set up to investigate the efficiency of adding 5% (w/w) individually of three different organic waste amendments [tea leaves, soycake and potato skin] to enhance the phytoaccumulation of Zinc and diesel fuel co-contaminated soil by Dracaena reflexa for a period of 180 days. Soil contaminated with Zn (80 mg kg-1DW) was spiked with an initial concentration of diesel fuel (25000 mg kg-1DW). Application of biowastes demonstrates significant degradation of DF compared to control soil. The highest rate of oil degradation was recorded in co-contaminated soil planted with D. reflexa and amended with SC (85%) followed by PS and TL (60 and 53.3%). Although the plants did not accumulate any hydrocarbon from the contaminated soil but there was significant bioaccumulation of Zn in the root and stem of Dracaena plant which was observed. At the end of 180 days, 16.5 mg/kg and 12.2 mg/kg of Zn in the root and the steam of D. reflexa was recorded. Results indicated that the D. reflexa could effectively extract Zn from Zn-contaminated soils even in the presence of diesel fuel concentration.