Phytoremediation of sewage sludge by Cymbopogon martinii (Roxb.) Wats. var. motia Burk. grown under soil amended with varying levels of sewage sludge

Abstract

Sewage sludge used as agriculture fertilizers contains a conspicuous amount of potentially toxic metals. In order to prevent the contamination in the food chain, there is an urgent need for the development of sewage sludge clean up technology. The use of non-food, multi-harvest aromatic crops for phytoremediation of sewage sludge has many benefits. Besides the eco-friendly approach, plant biomass generated can be used to extract economically important essential oil free of heavy metals. Cymbopogon martinii was grown in soil (s) amended with different ratios of sewage sludge (ss), that is, 100s:0ss (control), 80s:20ss, 60s:40ss, 40s:60ss, 20s:80ss, and 0s:100ss. The experiment was conducted in a plastic sack under an open environment for 1 year and harvesting was done thrice. Plant growth and essential oil yield were significantly increased with the increasing dose of sewage sludge. Accumulation of toxic metal (Cd, Cr, Pb, Ni) and micronutrient (Fe, Zn, Cu, Mn) increased significantly in the shoot tissues confirmed by estimation of bioaccumulation and bioconcentration, and scanning electron microscopy and X-ray microanalyses. Soil enzyme activities were significantly improved with the plant growth period and increased doses of sludge. Results showed C. martinii acts as hyper-accumulator and thus could be used for phytoremediation of sewage sludge.

Keywords:

• Aromatic grass
• Cymbopogon martinii
• metal removal
• plant growth
• SEM-EDX
• sewage sludge phytoremediation

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Acknowledgments

The authors are thankful to director CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow (India) for providing all the necessary facilities under institutional network Project-BSC0110. GS is grateful to the Council of Scientific and Industrial Research (CSIR), New Delhi, India for the award of Senior Research fellowship and also thankful to the Academy of Scientific and Innovative Research (AcSIR) for Ph.D. registration.

Disclosure statement

All authors declare that they have no conflict of interest.