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The impact of interactions between algal organic matter and humic substances on coagulation

SYSNO ASEP	0446391
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	The impact of interactions between algal organic matter and humic substances on coagulation
Author(s)	Pivokonský, Martin (UH-J)_{SAI, ORCID, RID} Načeradská, Jana (UH-J)_{SAI, ORCID, RID} Brabenec, T. (CZ) Novotná, Kateřina (UH-J)_{SAI, ORCID, RID} Barešová, Magdalena (UH-J)_{RID, ORCID, SAI} Janda, V. (CZ)
Source Title	Water Research. - : Elsevier - ISSN 0043-1354 Roč. 84, November (2015), s. 278-285
Number of pages	8 s.
Publication form	Print - P
Language	eng - English
Country	GB - United Kingdom
Keywords	coagulation ; Microcystic aeruginosa ; peptides/proteins ; Bovine serum albumin ; natural organic matter ; water treatment
Subject RIV	DJ - Water Pollution ; Quality
OECD category	Environmental sciences (social aspects to be 5.7)
R&D Projects	GAP105/11/0247 GA ČR - Czech Science Foundation (CSF)
Institutional support	UH-J - RVO:67985874
UT WOS	000362147400030
EID SCOPUS	84938685044
DOI	10.1016/j.watres.2015.07.047
Annotation	This study focuses on the effects of molecular interactions between two natural organic matter (NOM) fractions, peptides/proteins derived from cyanobacterium Microcystis aeruginosa (MA proteins) and peat humic substances (HS), on their removal by coagulation. Coagulation behaviour was studied by the jar tests with MA protein/HS mixtures and with single compounds (MA proteins or HS). Aluminium sulphate was used as a coagulant. Besides MA proteins, bovine serum albumin (BSA) was used as a model protein. For the MA protein/HS mixture, the removal rates were higher (80% versus 65%) and the dose of coagulant substantially lower (2.8 versus 5.5 mg L^-1 Al) than for coagulation of single HS, indicating the positive effect of protein-HS interactions on the coagulation process. The optimum coagulation pH was 5.2e6.7 for MA proteins and 5.5e6 for HS by alum. The optimum pH for the removal of MA protein/HS mixture ranged between pH 5.5e6.2, where the charge neutralization of negatively charged acidic functional groups of organic molecules by positively charged coagulant hydroxopolymers lead to coagulation. MA proteins interacted with HS, probably through hydrophobic, dipoleedipole and electrostatic interactions, even in the absence the coagulant. These interactions are likely to occur within a wide pH range, but they result in coagulation only at low pH values (pH < 4). At this pH, the negative charge of both MA proteins and HS was suppressed due to the protonation of acidic functional groups and thus the molecules could approach and combine forming aggregates. Virtually the same trends were observed in the experiments with HS and BSA, indicating that BSA is a suitable model for MA proteins under experimental conditions used in this study. The study showed that increases in organic content in source water due to the release of algae products may not necessarily entail deterioration of the coagulation process and a rise in coagulant demand.
Workplace	Institute of Hydrodynamics
Contact	Soňa Hnilicová, hnilicova@ih.cas.cz, Tel.: 233 109 003
Year of Publishing	2016

Number of the records: 1