Removal performance of lignin compound from simulated pulping wastewater using emulsion liquid membrane process

Abstract

Removal of lignin from pulping wastewater has considerable interest due to high market value in conversion to external biofuel and specialty chemicals. Thus, it is important to remove lignin for increasing revenue while reducing environmental problems. Removal of lignin from simulated pulping wastewater using emulsion liquid membrane (ELM) was proposed in this study. Thereby, optimum removal performance of the ELM was achieved by identifying the best set of liquid membrane formulation and affect parameter conditions. Selection of liquid membrane component was made on the basis of conventional liquid-liquid extraction studies to accomplish the extraction study in ELM process. The liquid membrane was formulated by dissolving the carrier trioctylamine (TOA) in kerosene as the diluent, sodium chloride (NaCl) as receiving phase and Span 80 as surfactant. The results showed that the optimum condition can be achieved at feed phase pH of 3, 3% (w/v) of surfactant concentration, 5 minutes of extraction time, 250 rpm of agitation speed, 0.1 M TOA, 1:10 of treat ratio and 1.5 M of NaCl. At these conditions, a stable emulsion was performed and 94% of lignin was extracted.