Naphthalene degradation in the presence of natural–synthetic surfactants mixture by mixed bacterial cultures

• Plant surfactant (Reetha) can be used for surfactant enhanced biodegradation process.
• Plant–synthetic mixed surfactant system can reduce consumption of synthetic one.
• Biodegradable plant surfactant is environmentally safe.

Biosurfactants are the most probable future candidates to substitute the synthetic surfactants in the area of applied surfactants research. Herein we focused on the natural plant based surfactant (Reetha) extracted from the pod of Sapindus mukorossi and its substitution potential with synthetic surfactants (TX-100, CTAB, and SDBS). Mixture of Reetha and synthetic surfactants was tested for the biodegradation of naphthalene. The biodegradation efficiency of surfactants against two mixed bacterial cultures viz., defined or known culture (KC) and mining waste water culture (WWC) was investigated. Addition of Reetha in the presence of ionic surfactants has increased the degradation efficiency of naphthalene. Degradation rate constants (K) and zeta potential assessments revealed that WWC has more potential than KC with surfactant mixtures (especially CTAB-Reetha). The highest degradation potential (K value = 0.31) was identified with WWC having 0.5 mol fraction of Reetha in CTAB-Reetha combination. The results suggested that the use of Reetha in combination with ionic surfactants has an enormous potential to make the biodegradation process more eco-friendly and economical by decreasing the surfactant cost.

Biodegradation of naphthalene in Reetha–synthetic mixed surfactants micellar media.Figure optionsDownload as PowerPoint slide