Strength of Flocs Formed by the Complexation of Lysozyme with Leonardite Humic Acid

Strength of Flocs Formed by the Complexation of Lysozyme with Leonardite Humic Acid

Aggregation and aggregates properties of natural organic and nanosized macromolecules such as humic substances and proteins are crucial to explore so-called colloid-mediated transport and the fate of substances in soil and water environments. Therefore, the aggregation and dispersion, charging, and...

Full description

Saved in:
Bibliographic Details
Published in:Polymers Vol. 12; no. 8; p. 1770
Main Authors: Wan Abdul Khodir, Wan Khairunnisa, Hakim, Azizul, Kobayashi, Motoyoshi
Format: Journal Article
Language:English
Published: Basel MDPI AG 01-08-2020
MDPI
Subjects:
Acids
Agglomeration
Aggregates
Enzymes
Experiments
Humic acids
Humic substances
Lysozyme
Macromolecules
Mass ratios
Proteins
Soil water
Strength
Volumetric analysis
United States > US
Japan
Germany
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Aggregation and aggregates properties of natural organic and nanosized macromolecules such as humic substances and proteins are crucial to explore so-called colloid-mediated transport and the fate of substances in soil and water environments. Therefore, the aggregation and dispersion, charging, and floc strength of lysozyme (LSZ)–leonardite humic acid (LHA) flocs were experimentally investigated. The experiments were performed in different salt concentrations and LSZ to LHA mass ratios as a function of pH. We obtained the stronger flocs at pH 4.4, where the isoelectric point (IEP) of the complex with the mass ratio 2.5 was confirmed. Thus, the aggregation of LSZ–LHA flocs is mainly caused by charge neutralization. We obtained the floc strength of 4.7 nN around IEP at low salt concentration of 3 mM, which was stronger than 2.8 nN in high salt concentration of 50 mM. The effect of salt concentration can be rationalized by charge-patch attraction at low salt concentration. With increasing mass ratio, the IEP shifted to higher pH. This is due to the increase in positive charge from LSZ in the mixture. The effect of the LSZ to LHA mass ratio on the maximum strength was weak in the range studied.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:2073-4360
2073-4360
DOI:10.3390/polym12081770