Structure of Flocs of Latex Particles Formed by Addition of Protein from Moringa Seeds

Published

October 20, 2014

Author(s)

Maja S. Hellsing, Habauka M. Kwaambwa, Fiona M. Nermark, Bonang B. M. Nkoane, Andrew J. Jackson, Matthew John Wasbrough, Ida Berts, Lionel Porcar, Adrian R. Rennie

Abstract

Proteins extracted from the seeds of Moringa trees are effective flocculents for particles dispersed in water and they are attractive as a natural and sustainable product for water purification. Studies with a model system consisting of polystyrene latex particles have shown that the protein adsorbs to the surface and causes flocculation. Small-angle neutron scattering that exploits contract matching of deuterated particles dispersed in D₂O to highlight bound protein has allowed the maximum adsorbed amount to be determined as about 3 mg m^-2. It is possible to form very compact flocs that are characterized by fractual dimensions that approach the theoretical maximum of 3. Ultra small-angle neutron scattering allows these to be characterized for a range of particle and protein concentrations. Protein from Moringa stenopetala seeds gave rise to lower fractal dimensions compared to Moringa oleifera, but still much larger than values observed for conventional ionic flocculents that are in the range 1.75 to 2.3. These compact flocs are desirable for efficient separation of impurities and dewatering of sludge. A trend of increasing fractal dimension with particle concentration was observed when Moringa stenopetala seed protein was used and this resembles behavior predicted previously in Brownian dynamics simulation of flocculastion.

Citation

Colloids and Surfaces A-Physicochemical and Engineering Aspects

Volume

460

Pub Type

Journals

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Citation

Hellsing, M. , Kwaambwa, H. , Nermark, F. , Nkoane, B. , Jackson, A. , Wasbrough, M. , Berts, I. , Porcar, L. and Rennie, A. (2014), Structure of Flocs of Latex Particles Formed by Addition of Protein from Moringa Seeds, Colloids and Surfaces A-Physicochemical and Engineering Aspects, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914126 (Accessed May 4, 2024)