Indian Journal of Science and Technology

Abstract

Water is fundamental in all ecosystems and indispensable for different biological processes: anthropic processes have altered the quality and quantity of water and caused imbalances. The water in the upper basin of the river Bogotá shows high levels of turbidity, due to non-dissolved solids like algae, muds, microbes or other particles, caused by the shedding of wastes, which absorb and disperse the light which pierces them, and thus increase the degree of turbidity and reduce the quality of the water. Aim: To assess the effect, as natural coagulants, of the seeds of guayaba (guava), Psidium guajava L, or the episperm of the seeds of avocado, Persea americana. Method: We used the jar test with parameters of design and control in standardized conditions, different combinations of doses of the coagulant and a rapid mixture time, velocity gradient and sedimentation time for the evaluation of three extracts of each seed in its respective solution of water, one with 10% ethanol and another with 10% acetic acid. Three tannins were used as an organic control: quebracho (Schinopsis balansae), mimosa (Acacia dealbata) and castaño (chestnut, Castanea sativa); and aluminum sulfate () was used as an inorganic control. The water samples were taken from the upper basin of the río Bogotá in La Marinilla sector, near the road between Chocontá and Villapinzón. Findings: In all cases, it was found that the use of the extract of the Psidium guajava L in a water solution with 10% of acetic acid reduced the levels of turbidity, with an effectiveness of 99.15% and 98.36%. The results obtained from the episperm of the seeds of avocado, Persea americana Mill. likewise showed a reduction in the levels of turbidity, with the extract in a solution with 10% of acetic acid the most effective, at 80.45%. Castaño was the tannin which showed the highest yield, with an effectiveness of 93.72%. Application: This investigation not only showed benefits in the search for new alternatives for natural coagulants but it also highlighted the importance of being able to reuse industrial residues.

Keywords: Coagulant Activity, Persea americana Mill. Psidium guajava L