Zing Yi Ooi

Recovery of kraft lignin from pulping wastewater via emulsion liquid membrane process

Kraft lignin (KL) is a renewable source of many valuable intermediate biochemical products currently derived from petroleum. An excessive of lignin comes from pulping wastewater caused an adverse pollution problems hence affecting human and aquatic life. A comprehensive study pertaining to emulsion liquid membrane (ELM) extraction of lignin from pulping wastewater was presented. ELM formulation contains Aliquat 336 as carrier, kerosene as diluent, sodium bicarbonate (NaHCO3) as stripping agent and Span 80 as surfactant. The emulsion stability was investigated at different surfactant concentrations, homogenizer speed and emulsification time. Modifier (2‐ethyl‐1‐hexanol) was added to avoid segregation of third phase while improving the emulsion stability. At optimum conditions, 95% and 56% of lignin were extracted and recovered, respectively at 10 min of extraction time, 0.007 M of Aliquat 336, 0.1 M of NaHCO3 and 1:5 of treat ratio. Additional of modifier was contributed to highest recovery up to 98%. The ELM process was found to be equally feasible and quite effective in the recovery of KL from real pulping wastewater. Therefore, ELM process provides a promising alternative technology to recover KL from pulping wastewater while solving the environmental problems simultaneously.

Response surface optimization of kraft lignin recovery from pulping wastewater through emulsion liquid membrane process

Kraft lignin (KL) represents a key sustainable source of biomass for transformation into biofuels and high-value specialty chemicals. Excess lignin in pulping wastewater creates pollution problems, hence affecting human. Thus, the KL recovery from pulping wastewater by emulsion liquid membrane was investigated and optimized using response surface methodology in this study. The liquid membrane was prepared by dissolving carrier tricaprylylmethylammonium chloride (Aliquat 336) and hydrophobic surfactant sorbitan monooleate (Span 80) in kerosene (diluent) with sodium bicarbonate (NaHCO3) as the internal stripping phase and 2-ethyl-1-hexanol as the modifier. The comparison between the experimentally optimized, and the RSM optimized values was accomplished by optimizing the following parameters: carrier and stripping agent concentration and treat ratio of emulsion to feed phase. The maximum KL recovery of 97% was obtained under the optimum condition at 0.012 M of Aliquat 336, 0.32 M of NaHCO3, and 1:4.8 of treat ratio.

The Role of Internal Droplet Size on Emulsion Stability and the Extraction Performance of Kraft Lignin Removal from Pulping Wastewater in Emulsion Liquid Membrane Process

It has been discovered that the size of internal droplets in primary emulsion determines emulsion dispersion and stability in emulsion liquid membrane (ELM) process for removal of lignin from pulping wastewater. Generally, primary emulsion contains kerosene, Aliquat 336, sodium bicarbonate, as well as Span 80 as diluent, carrier, internal phase, and surfactant, respectively. Hence, this study had looked into the parameters, including concentration of surfactant, carrier, and stripping agent; emulsification speed and time; as well as agitation speed and time. As a result, the diameter of the smallest droplets (1.4 µm) was formed with maximum lignin extraction (95%), minimum swelling (5%) at 3% (w/v) surfactant concentration, 12,000 rpm of emulsification within 5 minutes, 0.01 M of Aliquat 336, 0.1 M of NaHCO3, and 250 rpm of extraction within 10 minutes. GRAPHICAL ABSTRACT

Removal of Reactive Dye by Flat Sheet-Supported Liquid Membrane Using Tridodecylamine as a Carrier

The discharging of reactive dye-containing wastewater from the textile industry causes environmental destruction and serious health problems. The application of supported liquid membrane (SLM) as a water treatment process has gained strong attention today. In this study, SLM process was used to remove and recover reactive dye from wastewater. Reactive dye, Red 3BS, was removed and recovered through SLM assisted by tridodecylamine (TDA) as a carrier and sodium hydroxide as a stripping agent. The parameters governing the transportation of Red 3BS such as pH of feed phase, concentration of strip phase, and concentration of feed phase were investigated. The results show that almost 100 % and 60 % of 50 ppm Red 3BS was selectively removed and recovered, respectively, using 0.1 M TDA and 0.1 M NaOH at pH 3 of the feed phase.