Bioremediation of naphthalene in water by Sphingomonas paucimobilis using new biodegradable surfactants based on poly (epsilon-caprolactone). Articles uri icon

publication date

  • December 2008

start page

  • 217

end page

  • 223

issue

  • 2

volume

  • 63

International Standard Serial Number (ISSN)

  • 0964-8305

Electronic International Standard Serial Number (EISSN)

  • 1879-0208

abstract

  • New amphiphilic block surfactants ABA based on a central segment of polycaprolactone with different molecular composition were evaluated in the bioremediation of naphthalene in water by Sphingomonas paucimobilis and compared with sodium dodecyl sulphate as reference surfactant (SDS). Also the biodegradation of the new surfactants by bacteria, S. paucimobilis and a mixture of bacteria (Pseudomonas aureginosa, Bacillus subtilis,Bacillus amyloliquefaciens and Bacillus megaterium) was studied by indirect impedance technique and carbon dioxide determination. All the bacteria biodegraded in solution and micellar phase the central segment of PCL with mineralization rates in the range of 0.024&-0.036 mg of CO2 per day. S. paucimobilis biodegraded naphthalene in the presence of the new surfactants and GC analysis demonstrated that conversion to products started immediately after inoculum. In all the experiments, except for SDS, at 140 h of incubation time, the remaining naphthalene concentration was about 10% of the initial concentration. In contrast, the production of CO2was delayed 4&-7 days and values around 75% of naphthalene mineralization degree were achieved in three weeks. The addition of PCL-surfactants, in solution and in micellar phase, not interfered in the naphthalene mineralization. These results have shown promising potential of these biodegradable PCL-surfactants in surfactant-enhanced remediation (SER) technology for removing residual organics from contaminated groundwater and soils.

subjects

  • Chemistry
  • Materials science and engineering

keywords

  • biodegradation; bioremediation; surfactants; polycaprolactone; pseudomonas; bacillus; indirect impedance technique; naphthalene