@article{oai:tsukuba.repo.nii.ac.jp:00029511, author = {Kobayashi, Motoyoshi and 小林, 幹佳}, issue = {14}, journal = {Water Research}, month = {Sep}, note = {To obtain the strength of flocs against breakup is crucial for controlling flocculation in water treatment and predicting transport of colloidal particles in aqueous environments. Recently, the author reported a method to obtain floc strength from a simple experiment of floc breakup subjected to a laminar converging flow. In this study, this method was applied to natural soil flocs. The flocs were formed by coagulation with 0.5 M NaCl (pH 5.4–5.5, pH 6.6) solutions, 0.1 M CaCl2 (pH 6.4–6.9) solutions, or acidified distilled water with dilute HCl (pH 5.6). Obtained floc strengths were 0.3, 0.7 and 4 nN for Na-, Ca-, and H-coagulated flocs, respectively. Also, floc strength did not change with floc size. These values of floc strengths were 1–3 orders smaller than those of flocs formed with polymer flocculants and/or precipitated ferric or aluminum coagulants.}, pages = {3273--3278}, title = {Strength of natural soil flocs}, volume = {39}, year = {2005}, yomi = {コバヤシ, モトヨシ} }