Removal of cyanobacterial blooms in Taihu Lake using local soils. I. Equilibrium and kinetic screening on the flocculation of Microcystis aeruginosa using commercially available clays and minerals.
Algal removal abilities of 26 clays/minerals were classified into three categories according to the 8-h equilibrium removal efficiency (Q8h) and removal rate at a clay loading of 0.7 g/L. Type I clays (sepiolite, talc, ferric oxide, and kaolinite) had a Q8h > 90%, a t50 (time needed to remove 50% of the algae) < 15 min, and a t80 < 2.5 h. Type II clays (6 clays) had a Q8h 50-90%, a t50 < 2.5 h, and a t80 > 2.5 h. Type III clays (14 clays) with Q8h < 50%, t50 > 8 h and t80 > 14 h had no practical value in removal of algal blooms. When the clay loading was reduced to 0.2 g/L, Q8h for all the 25 materials decreased to below 60%, except for sepiolite whose Q8h remained about 97%. The high efficiency for sepiolite to flocculate M. aeruginosa cells in freshwaters was due to the mechanism of netting and bridging effect.
Pan
Gang
G
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. gpan@mail.rcees.ac.cn
Zhang
Ming-Ming
MM
Chen
Hao
H
Zou
Hua
H
Yan
Hai
H
D000538:Aluminum Silicates; D000863:Antacids; D002681:China; D000077215:Clay; D005068:Eutrophication; D005290:Ferric Compounds; D005427:Flocculation; D005618:Fresh Water / Q000382:microbiology*; D007616:Kaolin; D007700:Kinetics; D017633:Magnesium Silicates; D046931:Microcystis; D008903:Minerals; D012987:Soil; D013627:Talc
D000538:Aluminum Silicates; D000863:Antacids; D005290:Ferric Compounds; D017633:Magnesium Silicates; D008903:Minerals; D012987:Soil; D013627:Talc; C000499:ferric oxide; D007616:Kaolin; C001671:magnesium trisilicate; D000077215:Clay