Processo preliminar de retrolavagem em reator de leito fixo bifluxo (RLF-BF) aplicado a potabilização de água subterrânea do meio rural

Abstract

The treatment technologies applied to water purification in rural Brazil are insipient and the proposition of new technologies must meet the potability standards described in Ordinance No. 888/2021 of the Ministry of Health (MS). Therefore, the objective of this study was to analyze the efficiency of a preliminary Bi-Flow Fixed Bed Reactor Backwash (RLF-BF) process developed by Alves (2018), on a pilot scale. To this end, 15 filtration runs were carried out in the RLF-BF, which included the process of filtration (sand) and filtration/adsorption with granular activated carbon from the babassu epicarp with average granulometries of 1 mm. After carrying out 15 filtration rows and reaching the maximum head loss, the filter bed backwashing process was carried out in an upward direction with a maximum expansion of the filter bed of approximately 125%. After the backwash process, 10 filtration runs were carried out again. The parameters turbidity (uT), apparent color (uH), absorbance (λ– 254 nm), hydrogenion potential (pH), free chlorine (mg L-1), alkalinity (mg L-1), calcium hardness (mg L-1) and total and thermotolerant coliforms, in the pre and post backwash filtration runs and during the backwash. The water used in the filtration lines before and after the backwash came from an artesian well originating in the rural area of the municipality of Cerro Largo and the backwash water from a public supply well under the responsibility of Companhia Rio Grandensse de Saneamento (CORSAN). The backwash to reach the maximum head loss in the filter bed performed with expansion of the filter bed in approximately 125% showed a reduction of 98.72 and 94.83% in relation to the apparent color and turbidity parameters, respectively. Proving to be efficient in the conditions of study carried out. The study was carried out at the Water and Ecotoxicology Laboratory of the Federal University of Fronteira Sul (UFFS), Campus Cerro Largo/RS.