Remediation of soil contaminated with copper using Rhamnolipids produced from Pseudomonas aeruginosa MTCC 2297 using waste frying rice bran oil

Abstract

Rhamnolipids production by Pseudomonas aeruginosa MTCC 2297 was studied, using waste frying rice bran oil as carbon substrate. Response surface methodology was employed to arrive at the optimum production condition. Maximum rhamnolipids production (7.6 g/l) was attained with waste frying rice bran oil at 34.8 g/l, with sodium nitrate at 3.9 g/l. Optimum temperature and initial pH were found to be 34°C and 7.4. Batch washing experiments were used to evaluate the efficiency of rhamnolipids on remediating coppercontaminated soils. Synthesized rhamnolipids were used at different concentrations from 0.5 to 2% with and without 1% sodium hydroxide at a fixed ratio of 4:1. It was found out that 2% rhamnolipids removed 71% and 74% of copper from soil with initial concentrations 474 and 4,484 ppm, respectively. The use of waste frying oil in the production of rhamnolipids which was used in the bioremediation of copper-contaminated soil results in an environmentally friendly, cost-effective, and specific alternative to various physical and chemical methods of remediating polluted soil.

Influence of Soil Chemistry and Plant Physiology in the Phytoremediation of Cu, Mn, and Zn

“…These amphiphilic molecules have the capacity to form complexes with trace metals at the soil interface and to desorb trace metals from soil matrix, further increasing their solubility and bioavailability in the soil solution (Venkatesh and Vedaraman, 2012).…”

Advances in applications of rhamnolipids biosurfactant in environmental remediation: A review

“…Juwarkar, Dubey, Nair, and Singh () observed that when di‐rhamnolipid produced by Pseudomonas aeruginosa BS2 was applied in the remediation of metal contaminated soil, the removal efficiency of metals shows the order of Cd = Cr>Pb = Cu>Ni. Venkatesh and Vedaraman () investigated the remediation of soil contaminated by copper using rhamnolipids produced by Pseudomonas aeruginosa MTCC 2297 with a batch washing experiment, and observed that 2% of rhamnolipids removed 74% and 71% of copper from soil with initial concentrations of 4,484 and 474 ppm, respectively.…”

“…Juwarkar, Dubey, Nair, and Singh (2008) observed that when di-rhamnolipid produced by Pseudomonas aeruginosa BS2 was applied in the remediation of metal contaminated soil, the removal efficiency of metals shows the order of Cd = Cr>Pb = Cu>Ni. Venkatesh and Vedaraman (2012) (Dahrazma et al, 2008;Zhong, Yang, et al, 2015), which in turn influence metal removal. For example, Aşçı et al (2007) The addition of other chemicals to rhamnolipid solutions may enhance the metal removal efficiency.…”

Sequential soil washing with mixed biosurfactants is suitable for simultaneous removal of multi-metals from soils with different properties, pollution levels and ages

“…The efficiency of Cu removal with RAM can be high when soil is not co-contaminated with other HMs. Venkatesh and Vedaraman applied a 2% RAM solution to soil spiked with only Cu and were able to remove 74% of the HM, even though its initial concentration was nearly 5000 mg/kg (Venkatesh and Vedaraman 2012).…”

“…In environmental remediation, they can act as ligands and have a strong affinity for HMs due to their carboxyl groups. Up to now, most studies on the use of RAM have involved Cu, Cd, Ni, Pb or Zn removal from soils via soil washing (at varying pH, concentrations of RAM or washing times) or soil flushing (at different concentration of RAM, flushing time or flow rate) (Mulligan and Wang 2006;Juwarkar et al 2007;Venkatesh and Vedaraman 2012;Wan et al 2015).…”