Speciation of organic matter in natural waters—interaction of polyacrylates and polymethacrylates with major cation components of seawater

摘要: Abstract The speciation of some high molecular weight polycarboxylates was studied in different ionic media. Polyacrylates here investigated ( W =2.0, 5.1 and 20.0 kDa) form weak species with alkali metal cations K =10 2 mol l −1 , t =25 °C, I =0 ) quite stable complexes alkaline earth >10 6 ). Results are reported from experiments performed a multicomponent electrolyte solution simulating the major composition seawater (artificial seawater). Protonation constants this medium expressed as polynomial function S 1/2 =salinity) sharp lowering respect to values obtained non-interacting aqueous tetraalkylammonium salts can be ascribed formation cation complexes. A simplified approach, according which salt is considered single 1:1 salt, used describe total interacting ability components towards polyacrylates. complex data degree proton dissociation weight: empirical equations take into account these functions also given.