Is polyaluminium chloride better than polyelectrolyte – alum-based coagulation?

At the Barekese Water Treatment Plant in Ghana, an alternative, the polyelectrolyte – polyaluminium chloride (PAC) is also used in coagulation but limited information is available on the operating conditions required to achieve better performance than alum-based coagulation.

Are polyaluminum chloride and polyelectrolyte composite coagulants effective in drinking water treatment?

Abdellah-Anouar. El Foulani, Mohamed. Tahiri & Polyaluminum chloride (PAC)/natural polyelectrolyte composite coagulants have received considerable attention recently due to their exceptional properties in drinking water treatment.

Do polyelectrolyte composite coagulants improve coagulation performance?

El Foulani, Mohamed. Tahiri & Polyaluminum chloride (PAC)/natural polyelectrolyte composite coagulants have received considerable attention recently due to their exceptional properties in drinking water treatment. However, the criteria for selecting polyelectrolytes grafted into the PAC to improve coagulation performance are not yet well defined.

What are composite coagulants based on Pac and polyelectrolytes?

Composite coagulants based on PAC and polyelectrolytes have been developed to increase the aggregation capacity of PAC and subsequently enhance treatment efficiency [13, 14, 15]. Organic–inorganic composite flocculants have the specificity of combining the advantages of these components to correct the deficiencies present in their individual uses.

What is PACL coagulation?

PACls are commonly prepared by controlled neutralization of aluminum chloride. PACls usually contain significant amounts of polynuclear aluminum hydrolysis products , including Al 13, which is considered to be among the more important species , . However, the coagulation mechanisms of PACl arenot fully understood to date.

Why do cationic polyelectrolyte coagulants increase bridging of adjacent colloids?

These results are due to the high gelation capacity of the anionic polyelectrolyte (sodium alginate) compared to the cationic polyelectrolyte (chitosan), which increases the bridging phenomenon [15, 40]. The addition of polyelectrolytes to composites coagulant promoted the bridging of adjacent colloids.