Combined alginate-humic acid fouling mechanism and mitigation during microfiltration: Effect of alginate viscosity

2021 ◽  
Vol 39 ◽  
pp. 101852
Author(s):  
Dagmar Ólafsdóttir ◽  
Bing Wu
Keyword(s):  
Humic Acid ◽  
Fouling Mechanism

scholarly journals New insights into the humic acid fouling mechanism of ultrafiltration membranes for different Ca2+ dosage ranges: results from micro- and macro-level analyses

2018 ◽  
Vol 77 (9) ◽  
pp. 2265-2273 ◽  
Author(s):  
Rui Miao ◽  
Ying Wu ◽  
Pei Wang ◽  
Gongzheng Wu ◽  
Lei Wang ◽  
...  
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Membrane Fouling ◽  
Layer Structure ◽  
Dominant Factor ◽  
Adhesion Forces ◽  
Fouling Mechanism ◽  
Wide Range ◽  
Three Stages ◽  
Main Factor

Abstract To reveal the mechanisms of the influence of Ca2+ on membrane fouling with humic acid (HA), the adhesion forces of HA with both other HA molecules and the membrane, the HA fouling layer structure, HA fouling experiments, and the HA rejections at a wide range of Ca2+ dosages were investigated. The results indicated that the effect of Ca2+ on HA fouling can be divided into three stages. At lower ionic strength (IS) of CaCl2, the change in electrostatic forces is the main factor in controlling HA fouling behavior; i.e., increasing Ca2+ dosages resulted in more serious membrane fouling. When the IS of CaCl2 reached 10 mM, HA aggregates became the dominant factor in the fouling process, which could result in a porous fouling layer accompanied by less membrane fouling. Interestingly, much weaker membrane fouling was observed when the IS increased to 100 mM and the HA rejection began to decline. This was because a stronger hydration repulsion force was generated, which could weaken the compactness of the fouling layer and the adhesion forces of HA with both the membrane and HA, while enabling smaller-sized HA to pass more easily into the permeate, which led to less membrane fouling and a lower HA rejection.

scholarly journals Probing fouling mechanism of anion exchange membranes used in electrodialysis self-reversible treatment by humic acid and calcium ions

2021 ◽  
pp. 100173
Author(s):  
M.A.C.K. Hansima ◽  
J. Ketharani ◽  
D.R. Samarajeewa ◽  
K.G.N. Nanayakkara ◽  
Ajith C. Herath ◽  
...  
Keyword(s):  
Humic Acid ◽  
Anion Exchange ◽  
Calcium Ions ◽  
Anion Exchange Membranes ◽  
Fouling Mechanism

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

Changes in the Humic Acid–Metal Complexation Characteristics Depending on Humification Degree / Humīnskābju – Metālu Kompleksveidošanās Rakstura Izmaiņas Atkarībā No Humifikācijas Pakāpes

2012 ◽  
Vol 51 (3) ◽  
pp. 228-237
Author(s):  
D. Dudare ◽  
M. Klavins
Keyword(s):  
Humic Acid ◽  
Stability Constants ◽  
Humic Acids ◽  
Complex Stability ◽  
Peat Layer ◽  
Raised Bog ◽  
Complexing Capacity ◽  
Humification Degree ◽  
Complexation Process ◽  
Complex Stability Constants

The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids isolated from two well-characterized raised bog peat profiles in respect to the basic properties and humification characteristics of the studied peats and their humic acids. The complex stability constants significantly change within the studied bog profiles and are well correlated with the age and decomposition degree of the peat layer from which the humic acids have been isolated. Among factors that influence this complexation process, molecular mass and ability to form micellar structures (supramolecules) of humic substances are of key importance.

Major and Trace Elements in the Humic Acid

2018 ◽  
Author(s):  
Zoltán Kis ◽  
Katalin Gméling ◽  
Tímea Kocsis ◽  
János Osán ◽  
Mihály András Pocsai ◽  
...  
Keyword(s):  
Trace Elements ◽  
Humic Acid ◽  
Activation Analysis ◽  
Analytical Techniques ◽  
Major And Trace Elements ◽  
Prompt Gamma Activation Analysis ◽  
Prompt Gamma ◽  
Gamma Activation ◽  
X Ray ◽  
Precise Analysis

We present precise analysis of major and trace elements of the humic acid. We used three different element analytical techniques in our investigations as prompt-gamma activation analysis (PGAA), neutron activation analysis (NAA) and X-ray fluorescence (XRF) analysis was carried out. We identified 42 elements in our sample.

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