Impact of extracted algogenic organic matter on coagulation performance

2015 ◽  
Vol 15 (3) ◽  
pp. 617-624 ◽  
Author(s):  
Linan Xing ◽  
Christopher W. K. Chow ◽  
Jiane Zuo ◽  
Dongsheng Wang ◽  
Rolando Fabris ◽  
...  

Understanding coagulation behaviour and treatability of waters impacted by algogenic organic matter (AOM) is important for waters with frequent algal blooms. Physico­­–chemical characteristics of AOM spiked into a water sample, before and after coagulation, were investigated using high-performance size exclusion chromatography (HPSEC) with UV and fluorescence detection, three dimensional-fluorescence excitation emission matrix (3D-FEEM) measurement and resin fractionation in which three fractions were determined including very hydrophobic acid (VHA), slightly hydrophobic acid (SHA) and hydrophilic fractions. Release of AOM from algal cells with consequential increases in dissolved organic carbon and UV absorbance led to changes in 3D-FEEM spectra indicative of increased aromatic protein presence. Changes in disinfection by-product formation potential after the AOM spiking indicated possible interactions between natural organic matter and AOM. A study of the treatability of the AOM spiked water using two coagulants, alum and a polyaluminum composite coagulant, was conducted with the relative percentages of UV absorbance values of both the SHA and hydrophilic fractions higher in the post coagulated AOM spiked water than in the coagulated water, with corresponding reductions in the VHA proportion. It was found that the increased SHA and hydrophilic components in the AOM spiked natural water were recalcitrant to removal by both coagulants.

2011 ◽  
Vol 64 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Qunshan Wei ◽  
Rolando Fabris ◽  
Christopher W. K. Chow ◽  
Changzhou Yan ◽  
Dongsheng Wang ◽  
...  

The character of dissolved organic matter (DOM) in source waters from two countries (Australia and China) was investigated using an extended fractionation technique by combining resin adsorption, ultrafiltration and high performance size exclusion chromatography. There are distinctive chemical characteristics associated with DOM origins. Australian sourced DOM had higher hydrophobic acid (HoA) content and exhibited a more pronounced humic character, indicating a higher influence from allochthonous organics (decayed plant bodies from vegetated catchments). The higher content of hydrophobic base and neutral components found in Chinese DOM, may be attributed to the effects of increasing pollution caused by the rapid urbanization in China. The molecular weights (MWs) of aquatic HoA are predominantly in the moderate (e.g. 1–10 kDa) or small (e.g. <1 kDa) ranges. This suggests that aquatic HoA should not be assumed as high MW organics without experimental validation. It is also found that some of the low MW compounds in our samples were hydrophobic, which could explain the observation of low MW organic compounds being able to be removed by conventional treatment processes.


2008 ◽  
Vol 57 (7) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seong-Nam Nam ◽  
Gary Amy

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.


2000 ◽  
Vol 6 (6) ◽  
pp. 449-456 ◽  
Author(s):  
F.J. Sánchez-Muniz ◽  
R. Arroyo ◽  
J.M. Sánchez-Montero ◽  
C. Cuesta

Information on digestibility and absorption of oils and fats used for frying is under debate. To get knowledge on this, unused palm olein (9.27 ± 0.10% w/w polar content), used frying palm olein with a moderate degree of alteration (14.81 ± 0.90% w/w polar content) and highly altered used frying palm olein (26.36 ± 0.30% w/w polar content) and their respective nonpolar and polar fractions were studied. Samples were analyzed by high-performance size-exclusion chromatography before and after a 20-min in vitro incubation with pancreatic lipase. Formation of monoacylglycerols and free fatty acids reflected no relevant differences between unused and moderately altered oleins, whereas the most altered olein was hydrolyzed to a much lesser degree. The presence of oligomers (dimers and polymers of triacylglycerols) negatively affected the hydrolysis of triacylglycerol monomers in whole oleins. The hydrolysis of these monomers in the isolated nonpolar and polar fractions ranked between 60.2% and 78.5%. Oligomers were efficiently hydrolyzed by pancreatic lipase in whole un used and moderately altered oleins but not in the most altered one. Polymers from isolated polar fractions were poorly hydrolyzed or not hydrolyzed at all. These data suggest that whole oleins contained some compounds that increase susceptibility of oligomers to enzymatic hydrolysis and that such compounds were not present in the polar fraction.


2011 ◽  
Vol 64 (8) ◽  
pp. 1685-1691 ◽  
Author(s):  
T. Li ◽  
B. Z. Dong ◽  
Z. Liu ◽  
W. H. Chu

Algogenic organic matter (AOM) was extracted from blue-green algae (cyanobacteria) and its characteristic was determined by various methods including high-pressure size-exclusion chromatography (HP-SEC), hydrophobic and hydrophilic fractionation, molecular weight (MW) fractionation and fluorescence excitation emission matrix (EEM). The results revealed that AOM was hydrophilic fractionation predominantly, accounting for 78%. The specific ultraviolet absorbance of AOM was 1.1 L/(mg m) only. The analysis for MW distribution demonstrated that organic matter greater than 30,000 MW accounted for over 40% and was composed of mostly neutral hydrophilic compound. EEM analyses revealed that protein-like and humic-substances existed in AOM. A test for membrane filtration exhibited that AOM could make ultrafiltration membrane substantial flux decline, which can be attributed to membrane pore clog caused by neutral hydrophilic compound with larger MW.


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