dc.contributor.author	Veerasamy, Devaraj
dc.date.accessioned	2024-04-18T00:53:04Z
dc.date.available	2024-04-18T00:53:04Z
dc.date.issued	2011
dc.description	Thesis (PhD. (Chemical Engineering)
dc.description.abstract	Fouling studies on natural rubber skim latex (NRSL) concentration using an integrated ultrafiltration membrane system has been conducted. This study focuses on parameters which influence fouling, identification of foulants, optimization of latex preservation system and subsequently identification of fouling mechanisms in NRSL concentration process. This investigation is divided into three stages. In the first stage, parameters affecting membrane fouling were studied by adopting an ideal preservation system for concentrating NRSL effectively. The second stage involves studying and identifying the major foulants in the ultrafiltration membrane system during the concentration of NRSL. The optimization of latex preservation system was conducted based on results from previous stages. Fouling mechanisms were identified to quantify all the hydraulic membrane resistances and subsequently the most significant resistances as well as the chemical nature of foulants were determined. The final stage of the study is to minimize the most significant resistance by in-situ ultrasonication in order to optimize the NRSL concentration process. The membrane resistances were quantified through membrane autopsy procedures and by using the resistance-in-series model. The pure water flux test was used to facilitate the design of an effective membrane cleaning procedure. Attenuated total internal reflection fourier transform spectrophotometer (FTIR-ATR), scanning electron microscope (SEM), atomic force microscope (AFM), energy-dispersive X-ray spectroscopy (EDX), atomic absorption spectrophotometer (AAS) and total organic carbon analyzer (TOC) were used in membrane autopsy procedures to characterize the foulants. Results show that the composite preservation system consisting of 0.3% ammonia and 0.2% ammonium laurate is the optimum preservation chemical composition for the concentration of NRSL. The concentration polarization resistance was found to be the highest of the membrane resistances during skim latex concentration process. The foulants identified are amino acids, rubber particles and protein derivatives. Alkaline (0.1M NaOH) and acid (0.1M HNO3) cleaning of the fouled polyvinylidene fluoride (PVDF) tubular membrane at a temperature of 50°C with ultrasonication, achieved the highest flux recovery of 93%. Concentration polarization membrane resistance was found to be the biggest threat to an efficient NRSL concentration process as it can develop at any time, at any trans-membrane pressure, and at any feed concentration. In-situ ultrasonication of 45 kHz frequency was applied to reduce the concentration polarization resistance during NRSL concentration process. The application of in-situ ultrasonication effectively reduced the time required to achieve the targeted concentration and cost savings by almost 30%. The integrated ultrafiltration membrane system developed in this study could effectively optimize the NRSL concentration. This newly developed system would become an economically and environmentally viable process to solve environmental problems associated with the natural rubber (NR) latex industry.
dc.description.sponsorship	Faculty of Chemical Engineering
dc.identifier.uri	http://openscience.utm.my/handle/123456789/1091
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.subject	Rubber—Research
dc.subject	Latex
dc.subject	Membranes (Technology)
dc.title	Fouling studies on natural rubber skim latex concentration using integrated ultrafiltration membrane system
dc.type	Thesis
dc.type	Dataset

Fouling studies on natural rubber skim latex concentration using integrated ultrafiltration membrane system

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