Evaluación de la efectividad de la semilla de Teberinto (Moringa oleífera Lam.) como método de remoción de arsénico y plomo en agua para consumo humano

Abstract

The present study was developed in the chemistry agricultural laboratory of the Faculty of Agronomic Sciences of the University of El Salvador, from June 2016 to April 2017. To evaluate the effectiveness of Moringa oleifera Lam. In the removal of arsenic and lead, at the laboratory level samples of water were prepared with a concentration of approximately 1.00 mg/l of arsenic (27 replicates) and 1.00 mg/l of lead (27 replicates), to which were added Three doses: 0.25, 0.50 and 1.00 g of Moringa oleifera Lam. seed meal per liter of prepared water sample. To obtain the flour, the seeds were dried and then crushed, then passed through a 0.5 mm sieve and a fine flour-like homogeneous powder was obtained and three reaction times: 1, 2 and 3 hours. After the reaction time had elapsed, the treated water was filtered, using a home filter to remove the flocs formed after the treatment. The homemade filter was made with: plastic bottles of alimentary grade that consisted of layers of: gravel and cotton of 6 cm each. The concentration of the metals in the water samples, before and after the treatments, was determined by calculating the percentage of removal of these metals and comparing the results obtained with the regulations for drinking water NSO 13.07.01: 08 (As 0.01 mg/l and Pb 0.01 mg/l). The analysis of the variables under study was governed by the Factorial Design, using the InfoStat 2014-E Statistical Program and the IBM PASS SPSS 22 Statistics Software, at a 95% confidence level. The factors studied were: Moringa oleifera Lam. Seed dose: 0.25, 0.50 and 1.00 g and removal time: 1, 2 and 3 hours; The dependent variables were: percentage of removal of arsenic and percent removal of lead expressed in percentage (%). The study concludes that the flour from Moringa oleifera Lam. Is effective in the removal of heavy metals. In the case of arsenic, the highest removal rate was 82.11% (1.00 g in 1 hour) and for lead the highest removal percentage was 99.90% (0.50 g in 3 Hours and 1.00 g in 2 and 3 hours). In spite of having removed more than 80% of arsenic, initial concentration of 1,025 mg/l, the values established by the NSO regulation 13.07.01: 08 (0.01 mg/l As) for drinking water were not met, obtaining a concentration Final (0.183 mg/l); In the case of lead, the concentrations removed above 98%, complied with the maximum limits required by regulations for drinking water NSO 13.07.01: 08 (0.01 mg/l Pb), and even presented values lower than the maximum allowed by said standard.