the purpose of this study was comparison of applicability of tertiary treatment of tehran domestic sewage with organic and inorganic coagulants or a combination of them. the far test procedure was applied utilizing: alum, polyelectrolyte wt 2600, anionic polyelectorlyte wt 3000, and nonionic polyelctrolyte wt 2690 as organic coagulants (products of calgon). the combination of lime with each of ...