Effect of the type of aluminium coagulant and water pH on the destabilization of colloids

• Autorzy: Świderska-Bróż M. , Rak M.
• Języki publikacji: EN

Abstrakty

EN

The study was conducted on a laboratory scale with the aim to examine how the type and dose of the aluminium coagulant as well as water pH influence the extent of colloid destabilization. The samples used for the purpose of the study contained water from the River Odra, with a natural or an adjusted pH, and were treated with aluminium sulphate (alum) or prehydrolyzed polyaluminium chlorides. The results obtained have revealed that polyaluminium chlorides are more efficient neutralizers of the negative electrokinetic potential of the colloids than alum. As a consequence, the substitution of alum by polyaluminium chlorides reduced the required concentration (g Al/m3) of watersoluble aluminium hydrolysis products which provided a comparable decrease in the absolute value of the ? potential. The efficiency of polyaluminium chlorides was found to increase with their basicity and with the polymerization of the products of aluminium prehydrolysis. A major factor contributing to the value of the negative ? potential of the colloids and to the extent of their destabilization was the concentration of H+ ions. The decrease in the pH value was concomitant with the decrease in the absolute value of the ? potential of the colloids that were present in the river water and with the increase in the extent of their destabilization by the coagulants examined. The effect of H+ ion concentration (in the water being treated) on the destabilization of colloids was the strongest with the alum coagulant and decreased with the increasing basicity of the polyaluminium chlorides tested.

Słowa kluczowe

EN

coagulation; pH effects; alkalinity; water treatment; aluminum

PL

koagulacja; pH efekt; kwasowość; oczyszczanie wody; glin; aluminium

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Environment Protection Engineering
• Rocznik: 2009
• Tom: Vol. 35, nr 4
• Strony: 63--72
• Opis fizyczny: bibliogr. 13 poz.

Twórcy

autor

Świderska-Bróż M.

autor

Rak M.

• Institute of Environmental Protection Engineering, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław,

Bibliografia

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