Sodium lignosulfonate alkylates based-biosurfactants for efficient remediation of oily sludge.

An alkylated sodium lignosulphonate (ALS) was prepared for highly efficient thermal washing treatment of oily sludge. The ALS was characterized for their chemical structure and surface activity. Furthermore, ALS was used as a thermal cleaning agent to treat oily sludge under different conditions to obtain an optimal thermal washing process. Finally, the oily sludge before and after thermal washing were characterized to explore its structural and compositional changes. Results obtained from the Fourier Transform Infrared spectroscopy (FT-IR) and Two-dimensional Heteronuclear Single Quantum Coherence(2D-HSQC) confirmed the successful grafting of fatty acid chains(C12) onto the LS molecules. ALS was an ideal surfactant with suitable HLB value and excellent surface tension reduction, foaming and emulsification properties. The optimum thermal washing process for oily sludge was: thermal washing temperature 30 °C, ALS concentration 1.5 g/L.