Cationic Polyelectrolytes – Anionic Surfactant Complexes Used in the Coagulation Flocculation Processes
نویسندگان
چکیده
S-a studiat experimental îndepărtarea particulelor fine de formazină din apă prin precipitare/coagulare cu complex de polielectrolit şi surfactant şi anume complex poliacrilamidă (produs industrial denumit Praestol 644, obţinut de Degussa) şi laurilsulfat de sodiu (SLS). S-a adăugat oxid de calciu pentru a iniţia precipitarea complexului de polielectrolit împreună cu particulele fine. S-au efectuat experimente cu complecşi având concentraţia de surfactanţi peste concentraţia de agregare critică (cac), cantitatea adăugată corespunzând potenţialului electrocinetic ξ nul pentru amestecul complex de formazină în suspensie. Utilizând metoda microscopiei video şi analizei imaginilor, s-a studiat cinetica procesului de floculare. Rezultatele au indicat durata optimă necesară formării flocoanelor. Au fost determinate viteza de sedimentare a flocoanelor, conţinutul de apă al precipitatului şi volumul de precipitat obţinut, turbiditatea iniţială şi finală a probelor de apă. Turbiditatea finală a apei a fost criteriul principal în determinarea condiţiilor optime de operare. Rezultatele testelor au arătat că, spre deosebire de metoda clasică de coagulare – floculare, în acest caz turbiditatea finală a apei şi durata procesului sunt mult mai mici, sedimentarea flocoanelor are loc mai rapid, dar conţinutul de apă şi volumul nămolului obţinut sunt mult mai ridicate. Utilizând aceste rezultate, au fost determinate condiţiile favorabile de operare.
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