RESEARCH ARTICLE Selective extraction and recovery of polyphenols from palm oil mill sterilization condensate using emulsion liquid membrane process Norela Jusoh 1 & Muhammad Bukhari Rosly 1 & Norasikin Othman 1,2 & Hilmi Abdul Rahman 1 & Norul Fatiha Mohamed Noah 1 & Raja Norimie Raja Sulaiman 1,2 Received: 17 June 2019 / Accepted: 2 February 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Polluted sterilization condensate discharged from palm oil mill may contain polyphenols that are rich in the antioxidant property. Emulsion liquid membrane (ELM) process is a promising method for polyphenol recovery due to its several attractive features such as high selectivity, simple operation, and low energy consumption. In this study, the condensate was characterized to determine its total phenolic content (TPC), ionic elements, and pH. ELM formulation containing tributylphosphate (TBP) as a carrier, kerosene as a diluent, sorbitan monooleate (Span 80) as a surfactant, and sodium hydroxide (NaOH) as a stripping agent was developed. The results show that sterilization condensate contains 700–1500 mg GAE/L of TPC. During the ELM process, more than 91% of extraction with 83% recovery and 8.3 enrichment were achieved at the favorable condition of 0.1 M TBP, external phase pH 5, 1 M NaOH, 1:5 treat ratio, 5% v/v of octanol as a modifier, and 100 mg GAE/L external phase concen- trations. Thus, ELM offers a potential alternative technology to extract and recover polyphenols from palm oil mill sterilization condensate while contributing to sustainable production. Keywords Palm oil mill effluent . Characterization . Liquid membrane formulation . Transport mechanism . Waste valorization Introduction Vegetable oils are parts of our common commodities. It has a wide variety of uses, including cooking oils and salad dress- ings, as well as in the production of shortening, margarine, and compound fat. They are also used in many processed products such as mustard, mayonnaise, french fries, non-dairy creamers, sandwich spread, and ice cream. The sources of vegetable oil manufacture are soybean, palm, rapeseed, sun- flower, olive, coconut, sesame, etc. Palm oil is one of the most widely consumed vegetable oil in the world, with global production volume amounted to 69.6 million metric tons in 2017/2018 (Statista 2019). Such mass production resulted in a large amount of palm oil mill effluent (POME), estimated at nearly three times the quantity of crude palm oil (CPO). For each ton of fresh fruit bunches (FFB) processed, an approximate of 0.67 tons of POME is generated (Ng et al. 2011). POME highly pollutes wastewater if it is discharged directly due to its high chemical oxygen demand (COD), biological oxygen demand (BOD), and suspended solids. In response to this issue, researchers worldwide have made various approaches to treat POME, including the inno- vation of other products such as fertilizers, biodegradable plastics, methane, biosurfactant, palm puree, and animal feeds (Liew et al. 2015, Mahlia et al. 2019). The sterilization process contributes a significant amount of wastewater that ended up in POME (Hariz and Takriff 2017). It is the earliest step in palm oil processing and one of the key processes that affect the production performance and palm oil quality. During the process, a lot of steam is used to soften the fruits and enhance the oil extractability, which leads to the generation of large amounts of wastewater. Recently, exploitation of crop processing residues as a poten- tial source of bioactive compounds such as polyphenols has been given much attention. Responsible Editor: Ta Yeong Wu * Norasikin Othman norasikin@cheme.utm.my 1 School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia 2 Centre of Lipids Engineering and Applied Research (CLEAR), Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia Environmental Science and Pollution Research https://doi.org/10.1007/s11356-020-07972-5