The released polysaccharide of the cyanobacterium Aphanothece halophytica inhibits flocculation of the alga with ferric chloride
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The effect of the released polysaccharide (RPS) of the cyanobacterium Aphanothece halophytica GR02 on the recovery of the alga by flocculation with ferric chloride was studied. With increasing RPS concentration in algal cultures from 0 to 68 mg L−1 the flocculation efficiency at the same dosage of ferric chloride decreased, and higher dosages of ferric chloride were required to attain the same flocculation efficiency. It is demonstrated that RPS could form complexes with ferrum during flocculation. In conclusion, RPS of A. halophytica GR02 had a significant inhibitory effect on flocculation of the alga with ferric chloride. The inhibitory mechanism of A. halophytica GR02 RPS allows the RPS to compete for ferrum by forming complexes with ferrum, thus leading to the consumption of ferrum in ferric chloride.
KeywordsReleased polysaccharide Flocculation Ferric chloride Cyanobacterium Aphanothece halophytica
This study was sponsored by the National Natural Science Foundation of China (No. 30670400) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.
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