Harvesting of different microalgae through 100-μm-pore-sized screen filtration assisted by cationic polyacrylamide and specific extracellular organic matter

The presence of algae in a drinking water source can have a significant impact on the treatment of that water. Algae and their extracellular organic matter can be precursors for disinfection by-product (DBP) formation which is of concern for treatment plants that employ pre-chlorination. This research examined the DBP formation of suspensions of Scenedesmus quadricauda, a green alga, and the effect of ozonation on that formation. Trihalomethane formation potential (THMFP) was found to increase by 10% to 30% when preozonation was applied versus non-ozonated samples. A slight increase in haloacetic acid (HAA) formation was also observed in the ozonated samples. Ozonation caused an increase in the dissolved organic carbon content of the algal suspension, thereby increasing the concentration of precursors. The alkalinity of the water did not significantly affect the formation potential of either THMs or HAAs.

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Assimilable organic carbon formation from algogenic organic matter and its variation by chlorination

Water Science & Technology Water Supply ◽

10.2166/ws.2006.075 ◽

2006 ◽

Vol 6 (2) ◽

pp. 239-244 ◽

Cited By ~ 1

Author(s):

J. Kim ◽

S. Lee ◽

S. Xu ◽

M. Akiba ◽

M. Nomura ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Culture Medium ◽

Algal Species ◽

Algal Growth ◽

Carbon Formation ◽

Chlorination Process ◽

Assimilable Organic Carbon ◽

Extracellular Organic Matter ◽

Death Phase

The objective of this study is to assess the importance of algae and algogenic organic substances concerned with the formation of assimilable organic carbon (AOC) during algal growth and chlorination process. Laboratory tests were carried out using cultures of algal species (Phormidium tenue) with different culture medium, M-11 and CT. Extracellular organic matter (EOM) produced during the stationary phase and death phase of P. tenue (106 cells/mL) with M-11 culture medium led to significant increase of the AOC concentration, up to 100 times as high as its initial concentration. In case of CT culture medium containing a high DOC component, the AOC concentration did not increase significantly during P. tenue culture. The formation and removal of AOC derived from EOM and intercellular organic matter (IOM) by chlorination were also examined. The AOC concentration after chlorination of EOM and IOM became maximum with 2 mg/L of chlorine dosage while it decreased with increase of chlorine dosage when the dosage was higher than 2 mg/L, suggesting that necessary chlorine dosage to not form AOC is higher than 2 mg/L.

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Water Solubility Enhancement of DDT by Humic Acid and Extracellular Organic Matter of Aquatic Algae

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.565 ◽

2012 ◽

Vol 518-523 ◽

pp. 565-568 ◽

Cited By ~ 2

Author(s):

Hua Ma ◽

Fu Yi Cui ◽

Zhi Wei Zhao ◽

Zhi Quan Liu ◽

Dong Mei Liu

Keyword(s):

Organic Matter ◽

Humic Acid ◽

Water Body ◽

Sampling Method ◽

Water Solubility ◽

Solubility Enhancement ◽

Absorption Coefficients ◽

Solution Ph ◽

Eutrophic Water ◽

Extracellular Organic Matter

The water solubility enhancement of 2,4´-DDT and 4,4´-DDT by humic acid and extracellular organic matter released from Microcystis aeruginosa was investigated by a ingenious sampling method and increasing apparent solute solubilities. Water solubility enhancements of the two DDT isomerizes by both humic acid and extracellular organic matter at the solution pH 7-11, and their solubilities increased with the increase of pH. Absorption coefficients Ciw (2,4´-DDT and 4,4´-DDT) increased with the increase of pH for HA and EOM, but Ciw for EOM are about two times than for HA at same TOC concentrations. The results suggested that more attentions should be paid to the enhancement of organic chemicals by EOM, especially in eutrophic water body where an increasing algae population usually appears, and the enhancement of DDT solubility by EOM may increase the risk of pesticide residues to organisms.

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