scholarly journals Modelling metal–humic substances–surface systems: reasons for success, failure and possible routes for peace of mind

2012 ◽  
Vol 76 (7) ◽  
pp. 2643-2658 ◽  
Author(s):  
P. E. Reiller
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Iron Oxides ◽  
Metal Surface ◽  
Natural Organic Matter ◽  
Organic Material ◽  
Ternary Systems ◽  
Mineral Surfaces ◽  
Satisfactory Description ◽  
Wide Range

AbstractIron oxides and oxyhydroxides are commonly of considerable importance in the sorption of ions onto rocks, soils and sediments. They can be the controlling sorptive phases even if they are present in relatively small quantities. In common with other oxides and clay minerals, the sorption pH-edge of metals is directly linked to their hydrolysis: the higher the residual charge on the metal ion, the lower the pH-edge. Modelling of this process has been successfully carried out using different microscopic or macroscopic definitions of the interface (e.g. surface complexation or ion exchange models that may or may not include mineralogical descriptions). The influence of organic material on the sorption of many metals is of significant. This organic material includes simple organic molecules and more complex exopolymeric substances (e.g. humic substances) produced by the decay of natural organic matter. Sorption of this organic material to mineral surfaces has been the subject of a large body of work. The various types of organic substances do not share the same affinities for mineral surfaces in general, and for iron oxides and oxyhydroxides in particular. In those cases in which successful models of the component binary systems (i.e. metal–surface, metal–organic, organic–surface) have been developed, the formation of mixed surface complexes, the evolution of the surface itself, the addition order in laboratory systems, and the evolution of natural organic matter fractions during sorption, have often precluded a satisfactory description of metal–surface–organic ternary systems over a sufficiently wide range of parameter values (i.e. pH, ionic strength, concentration of humic substances). This manuscript describes the reasons for some successes and failures in the modelling of the ternary systems. Promising recent advances and possible methods of providing more complete descriptions of these intricate systems are also discussed.

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

scholarly journals Using water hyacinth (Eichhornia crassipes) biomass and humic substances to produce urea-based multi-coated slow release fertilizer

Cellulose ◽  
2021 ◽  
Author(s):  
Iris Amanda A. Silva ◽  
Osmir Fabiano L. de Macedo ◽  
Graziele C. Cunha ◽  
Rhayza Victoria Matos Oliveira ◽  
Luciane P. C. Romão
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Nitrogen Fertilization ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Slow Release ◽  
Leaching Tests ◽  
Slow Release Fertilizer ◽  
Atmosphere System

AbstractUrea-based multi-coated slow release fertilizer was produced using water hyacinth, humic substances, and chitosan, with water rich in natural organic matter as a solvent. Elemental analysis showed that the nitrogen content of the fertilizer (FERT) was around 20%. Swelling tests demonstrated the effectiveness of the water hyacinth crosslinker, which reduced the water permeability of the material. Leaching tests showed that FERT released a very low concentration of ammonium (0.82 mg L−1), compared to the amount released from urea (43.1 mg L−1). No nitrate leaching was observed for FERT, while urea leached 13.1 mg L−1 of nitrate. In water and soil, FERT showed maximum releases after 30 and 40 days, respectively, while urea reached maxima in just 2 and 5 days, respectively. The results demonstrated the promising ability of FERT to reduce nitrogen losses, as well as to minimize environmental impacts in the soil–plant-atmosphere system and to improve the efficiency of nitrogen fertilization. Graphic abstract

Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques

2008 ◽  
Vol 57 (7) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seong-Nam Nam ◽  
Gary Amy
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Analytical Techniques ◽  
Size Exclusion ◽  
Effluent Organic Matter ◽  
Fluorescence Excitation ◽  
Wide Range ◽  
Exclusion Chromatography

Using three analytical techniques of size exclusion chromatography (SEC), fluorescence excitation-emission matrix (EEM), and dissolved organic nitrogen (DON) measurement, differentiating characteristics of effluent organic matter (EfOM) from natural organic matter (NOM) have been investigated. SEC reveals a wide range of molecular weight (MW) for EfOM and high amount of high MW polysaccharides, and low MW organic acids compared to NOM. Clear protein-like peaks using fluorescence EEM were a major feature of EfOM distinguishing it from NOM. Fluorescence index (FI), an indicator to distinguish autochthonous origin from allochthonous origin, differentiated EfOM from NOM by exhibiting higher values, indicating a microbial origin. In EfOM samples, DON present in higher amounts than NOM.

scholarly journals Fouling analysis of polysulfone ultrafiltration membranes used for drinking water treatment

2011 ◽  
Vol 11 (6) ◽  
pp. 668-674 ◽  
Author(s):  
B. Q. Zhao ◽  
C. P. Huang ◽  
S. Y. Chen ◽  
D. S. Wang ◽  
T. Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Ultrafiltration Membranes ◽  
Fluorescence Excitation ◽  
Hydrophobic Fraction

Natural organic matter (NOM) plays a significant role in the fouling of ultrafiltration membranes in drinking water treatment processes. For a better understanding of the interaction between fractional components of NOM and polysulfone (PS) ultrafiltration membranes used for drinking water treatment, fouling and especially the physically irreversible fouling of natural organic matter were investigated. Resin fractionation, fluorescence excitation–emission matrix (EEM) spectroscopy, fourier transform infrared spectroscopy (FTIR), contact angle and a scanning electron microscope (SEM) were employed to identify the potential foulants. The results showed that humic acid and fulvic acid of small size were likely to permeate the membrane, while the hydrophobic fraction of humic and fulvic acid and aromatic proteins tended to be rejected and retained. Organic compounds such as proteins, humic substances, and polysaccharide-like materials, were all detected in the fouling layer. The physically irreversible fouling of the PS membrane seemed to be mainly attributed to the hydrophobic fraction of humic substances.

Retention behaviour of humic substances onto mineral surfaces and consequences upon thorium (IV) mobility: case of iron oxides

2002 ◽  
Vol 17 (12) ◽  
pp. 1551-1562 ◽  
Author(s):  
Pascal Reiller ◽  
Valérie Moulin ◽  
Florence Casanova ◽  
Christian Dautel
Keyword(s):  
Humic Substances ◽  
Iron Oxides ◽  
Mineral Surfaces ◽  
Retention Behaviour

The role of humic substances in chromium sorption onto natural organic matter (peat)

Chemosphere ◽  
2006 ◽  
Vol 63 (11) ◽  
pp. 1974-1982 ◽  
Author(s):  
J. Kyziol ◽  
I. Twardowska ◽  
Ph. Schmitt-Kopplin
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Natural Organic Matter

Impact of natural organic matter coatings on the microbial reduction of iron oxides

2018 ◽  
Vol 224 ◽  
pp. 223-248 ◽  
Author(s):  
Christine Poggenburg ◽  
Robert Mikutta ◽  
Axel Schippers ◽  
Reiner Dohrmann ◽  
Georg Guggenberger
Keyword(s):  
Organic Matter ◽  
Iron Oxides ◽  
Natural Organic Matter ◽  
Microbial Reduction ◽  
Reduction Of Iron

scholarly journals NOM removal technologies – Norwegian experiences

2010 ◽  
Vol 3 (1) ◽  
pp. 1-9 ◽  
Author(s):  
H. Ødegaard ◽  
S. Østerhus ◽  
E. Melin ◽  
B. Eikebrokk
Keyword(s):  
Organic Matter ◽  
Activated Carbon ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Membrane Filtration ◽  
Granular Media ◽  
Physical Adsorption ◽  
Nanofiltration Membranes ◽  
Removal Technologies ◽  
Molecular Sieving

Abstract. The paper gives an overview of the methods for removal of natural organic matter (NOM) in water, particularly humic substances (HS), with focus on the Norwegian experiences. It is demonstrated that humic substances may be removed by a variety of methods, such as; molecular sieving through nanofiltration membranes, coagulation with subsequent floc separation (including granular media or membrane filtration), oxidation followed by biofiltration and sorption processes including chemisorption (ion exchange) and physical adsorption (activated carbon). All these processes are in use in Norway and the paper gives an overview of the operational experiences.

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