Ultrafiltration of humic acid solutions through unmodified and surface functionalized low-fouling polyethersulfone membranes – Effects of feed properties, molecular weight cut-off and membrane chemistry on fouling behavior and cleanability

2011 ◽  
Vol 81 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Polina Dobromirova Peeva ◽  
Aisyah Endah Palupi ◽  
Mathias Ulbricht
Keyword(s):  
Molecular Weight ◽  
Humic Acid ◽  
Acid Solutions

Characteristics of fouling due to clay-organic substances in potable water treatment by ultrafiltration

1996 ◽  
Vol 34 (9) ◽  
pp. 157-164 ◽  
Author(s):  
Kim C.-H. ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Size Distribution ◽  
Ultrafiltration Membrane ◽  
Organic Substances ◽  
Decomposition Products ◽  
Microbial Decomposition ◽  
Fouling Materials

Effects of clay on fouling due to organic substances and clay were evaluated by model fouling materials and kaolin. Model fouling materials selected were protein, polysaccharide, fulvic acid, humic acid and algogenic matter (EOM:ectracellular organic matter, microbial decomposition products) and kaolin was selected as the clay material. Polysulfone membrane (MWCO(Molecular Weight Cut-Off) 10,000, 50,000 and 200,000) was used as an ultrafiltration membrane. In particular, the flux measurement of solutions containing algogenic matter used an ultrafiltration membrane of MWCO 50,000. The flux of protein and polysaccharide with coexistence of kaolin increased in the case of the ratio of MW/MWCO being greater than one, but did not increase in the case of the MW/MWCO ratio being below one. In contrast, the flux of fulvic acid and humic acid with coextence of kaolin decreased regardless of the ratio of MW/MWCO. The addition of dispersion agent and coagulant in the organic substances and kaolin mixture solution changed the size distribution of kaolin, and resulted in a change of the flux. EOM and microbial decomposition products decreased with the increase of the fraction of organic matter having molecular weight more than MWCO of membrane. The flux of the algogenic organic matter with coexistence of kaolin decreased with the increase of the amount of kaolin. It was suggested that the decline of the flux with coexistence of kaolin was due to the change of the resistance of the kaolin cake layer corresponding to the change in kaolin size distribution with charge.

WETTABILITY OF MONTMORILLONITE CLAYS IN HUMIC ACID SOLUTIONS

2003 ◽  
Vol 51 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Juan de Dios García López-Durán ◽  
Asmae Khaldoun ◽  
Mohamed Larbi Kerkeb ◽  
María del Mar Ramos-Tejada ◽  
Fernando González-Caballero
Keyword(s):  
Humic Acid ◽  
Acid Solutions ◽  
Montmorillonite Clays

scholarly journals Evaluation of a 2-step thermal method for separating organic and elemental carbon for radiocarbon analysis

2014 ◽  
Vol 7 (1) ◽  
pp. 131-169 ◽  
Author(s):  
U. Dusek ◽  
M. Monaco ◽  
M. Prokopiou ◽  
F. Gongriep ◽  
R. Hitzenberger ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Humic Acid ◽  
Organic Carbon ◽  
Organic Compounds ◽  
Strong Evidence ◽  
Elemental Carbon ◽  
Intermediate Temperature ◽  
Thermal Method ◽  
Intermediate Step ◽  
Temperature Step

Abstract. We thoroughly characterized a system for thermal separation of organic carbon (OC) and elemental carbon (EC) for subsequent radiocarbon analysis. Different organic compounds as well as ambient aerosol filter samples were introduced into an oven system and combusted to CO2 in pure O2. The main objective was to test which combustion times and temperatures are best suited to separate OC and EC. The final separation step for OC was combustion at 360 °C for 15 min. Combustion at this temperature proved enough to remove several organic test substances from the filter (including high molecular weight humic acid) but did not remove substantial amounts of EC. For isolation of EC, OC first needs to be completely removed from the filter. This was achieved by water extraction of the filter, followed by combustion of the water insoluble OC at 360 °C and combustion at an intermediate temperature step of 2 min at 450 °C. This last step removed the most refractory OC together with some EC. Finally, the remaining EC was combusted to CO2 at 650 °C. The recovery of black carbon after the intermediate 450 °C step was approximately 80%. Several tests provided strong evidence that OC was removed efficiently during the intermediate temperature step: (i) brown carbon, indicative of refractory OC, was removed; (ii) the fraction modern of EC did not decrease significantly if the temperature of the intermediate step was further increased. Based on tests with various organic compounds, we estimated that charred organic carbon could contribute 4–8% to an elemental carbon sample that was isolated according to our method.

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