title: Bio-augmentation and nutrient amendment decrease concentration of mercury in contaminated soil.
abstract: Four mercury (Hg) contaminated soils with different pH (7.6, 8.5, 4.2 and 7.02) and total organic carbon contents (2.1, 2.2, 4 and 0.9%) were subjected to bioremediation utilizing a Hg volatilizing bacterial strain Sphingobium SA2 and nutrient amendment. In a field with ~280mg/kgHg, 60% of Hg was removed by bio-augmentation in 7days, and the removal was improved when nutrients were added. Whereas in artificially spiked soils, with ~100mg/kgHg, removal due to bio-augmentation was 33 to 48% in 14days. In the field contaminated soil, nutrient amendment alone without bio-augmentation removed 50% of Hg in 28days. Nutrient amendment also had an impact on Hg remediation in the spiked soils, but the best results were obtained when the strain and nutrients both were applied. The development of longer root lengths from lettuce and cucumber seeds grown in the remediated soils confirmed that the soil quality improved after bioremediation. This study clearly demonstrates the potential of Hg-reducing bacteria in remediation of Hg-contaminated soils. However, it is desirable to trap the volatilized Hg for enhanced bioremediation.
authors: Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia. Electronic address: KhandakerRayhan.Mahbub@uon.edu.au.
authors: Khandaker Rayhan
authors: KR
authors: Mahbub
authors: Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia.
authors: Kannan
authors: K
authors: Krishnan
authors: University of South Australia, Adelaide, SA 5001, Australia.
authors: Stuart
authors: S
authors: Andrews
authors: School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA 5000, Australia.
authors: Henrietta
authors: H
authors: Venter
authors: Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia.
authors: Ravi
authors: R
authors: Naidu
authors: Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, Callaghan, NSW 2308, Australia; Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC-CARE), Mawson Lakes, Adelaide, SA 5095, Australia.
authors: Mallavarapu
authors: M
authors: Megharaj
keywords: Bacterial volatilization; Bioremediation; Cucumber; Lettuce; Sphingobium