Introduction:

among the factors that affect the quality of water, we can mention suspended solids, which can be made up of organic and inorganic matter, hardness, pH, presence of bacteria, coliforms, etc.

Objective:

establish a comparison of the flocculation efficiency between two types of alum (KAl (SO4)2. 12H2O): commercial and prepared from recycling material (aluminum foil), used as a flocculating agent, in the inlet water of the Metropolitan University (Caracas).

Materials and Methodology:

water samples are taken, located at different points, within the University. They are characterized from the physicochemical point of view. Next, the coagulation-flocculation procedure is carried out, beginning with the determination of the isoelectric point, which will determine the appropriate pH, where the process will be carried out. The optimum concentration of the coagulant, necessary to achieve effective flocculation, is determined. The values obtained are, respectively, 47 ppm for commercial alum and 40 ppm for synthesized alum, from recycled material.

Results:

after applying the two types of alum, an improvement in the visual appearance of the samples (turbidity) was observed in both cases. It involved a reduction in absorbance (clarification), on average, of 73 % with commercial alum and 58 % for that obtained from recycled material. Regarding hardness, the decrease was 26 % and 27 % respectively and the decrease in conductivity, 70 % in both cases.

Conclusions:

from the investigation, the effectiveness of both types of alum, as a flocculating agent, emerges. In both cases the results were similar, which could lead to a low-cost method if commercial alum is substituted for alum prepared from recycled material.