scholarly journals Preparation of nanoclay embedded polymeric membranes for the filtration of natural organic matter (NOM) in a circular crossflow filtration system

2020 ◽  
Vol 37 ◽  
pp. 101408
Author(s):  
M.S. Seshasayee ◽  
Z. Yu ◽  
G. Arthanareeswaran ◽  
D.B. Das
2003 ◽  
Vol 3 (5-6) ◽  
pp. 155-164 ◽  
Author(s):  
J.-M. Laîné ◽  
C. Campos ◽  
I. Baudin ◽  
M.-L. Janex

Since the first membrane applications at the end of the 1980s, the water treatment engineering community has been able to develop reliable low pressure membrane systems that are capable of producing high quality drinking water at a competitive price, making membrane technology an attractive solution to both upgrade existing plants and design new ones. A competitive price means low capital and operating cost, which are inversely proportional to membrane hydraulic performance (permeate flux). Porous membranes lose their hydraulic performance as materials accumulate on their surfaces and/or within their pores, a process called membrane fouling. Although a significant effort has been devoted to elucidating the fouling mechanisms of polymeric membranes by natural organic matter (NOM), no single model has yet been accepted. In fact, most of the existing literature is contradictory, showing that membrane fouling is far from being fully understood. This article reviews over a decade of Ondeo's experience on characterizing and preventing fouling of polymeric membranes by natural organic matter and inorganic compounds. The review focuses on the role of NOM size and hydrophobicity, of membrane chemistry, and of solution pretreatment (coagulation and/or adsorption). In addition, the efficacy of some currently used strategies to minimize membrane fouling is also discussed.


2017 ◽  
Vol 35 (1) ◽  
pp. 137-140 ◽  
Author(s):  
Beata Malczewska

Abstract The application of microgranular adsorptive filtration (μGAF) has been successfully used in conjunction with membrane filtration. It proves to be efficient not only in removal of natural organic matter (NOM) but also it significantly reduces the extent of fouling. There are a few mathematical models evaluated to understand the underlying mechanism of fouling. This paper describes a method of predicting filtration capacities using constant flow datasets collected when μGAF was applied. The results suggest that the behaviour of fouling in microgranular adsorptive filtration system varies between different filtration operations and natural water quality. In analysed case the mechanism of pores blocking can be described by the complete blocking mechanism.


2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky

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.


2000 ◽  
Vol 49 (5) ◽  
pp. 269-280 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Ying-Shih Ma ◽  
Guor-Cheng Fang ◽  
Fang-Fong Zing

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho

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.


2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.


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