title: Flocculation of diatomite by methylated milk casein in seawater.
abstract: A new biodegradable flocculant was prepared from a common and inexpensive protein. Milk casein was methylated in a 0.05 M HCl methyl alcohol solution at room temperature. The methylated milk casein (MeCS), having a methylation degree of 81%, was applied to the separation or flocculation of diatomite in seawater (pH 8.1+/-0.1) at room temperature (18-23 degrees C). The flocculating ability of MeCS was evaluated by a sedimentation balance method (cumulative measurement method). The diatomite suspension was effectively flocculated by the addition of a small amount of MeCS (0.25 wt% of the diatomite weight). The results of sedimentation analysis showed that the size-frequency curve had a very sharp and high peak; thus the diatomite floc formed by MeCS had a rather uniform size. The settling velocity of diatomite floc at the appropriate MeCS dosages (0.25-2 wt% of diatomite) was about 3 x 10(-3) ms(-1).
authors.affiliation: Division of Marine Biosciences, Graduate School of Fisheries Sciences, Hokkaido University, Minato-Cho 3-1-1, 041-8611 Hakodate, Japan. seki@elsie.fish.hokudai.ac.jp
authors.forename: Hideshi
authors.initials: H
authors.lastname: Seki
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shinguh
authors.forename: Hideo
authors.initials: H
authors.lastname: Maruyama
mesh_terms: D000818:Animals; D002364:Caseins / Q000737:chemistry*; D007692:Diatomaceous Earth / Q000737:chemistry*; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D008745:Methylation; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D015233:Models, Statistical; D012623:Seawater / Q000737:chemistry*; D013696:Temperature
chemical_list: D002364:Caseins; D008894:Milk Proteins; D007692:Diatomaceous Earth; C033787:diatomite