Implantação e avaliação da eficiência de sistemas WCs acoplados a filtro de carvão ativado para o tratamento de água para consumo humano

Abstract

The changes in the physical, chemical, and biological properties of water sources have been increasing every year, because of many anthropogenic factors. Thus, the absence of treatment of water for consumption can lead to the emergence of waterborne diseases in humans. An alternative that adds to the efforts to mitigate the problem of supplying quality water are the constructed wetlands systems which, if associated with activated carbon filters, can be an efficient technology for treating surface water, with the aim of obtaining potable water. The differential of this system is that it uses low-cost materials for implementation in a real system, in addition to seeking to solve the problem of lack of drinking water for riverside populations in the Amazon. The objective of this work was to develop wetland systems built with vertical flow using the Alocasia macrorrhiza plant coupled to an activated carbon filter (CWCACF) for the treatment of water for human consumption and to evaluate the efficiency through physical-chemical, microbiological and metals parameters potentially toxic. Wetland systems built with vertical flow coupled to the activated carbon filter were built in Manaus/AM and three systems in single-family residences in communities in Itacoatiara/AM. To evaluate the efficiency of the CWCACF systems, the physical-chemical, microbiological parameters and potentially toxic metals were measured in the raw water and in the water treated by the constructed system. The physicochemical parameters were pH, dissolved oxygen (DO), electrical conductivity (EC), turbidity, total suspended solids (TSS) nitrate (N-NO3-), nitrite (N-NO2-), ammonia (N-NH4+), phosphate (P-PO43-) and sulfate (SO42-). The microbiological parameters were total and thermotolerant coliforms (Escherichia coli) and the potentially toxic metals were copper (Cu), zinc (Zn), lead (Pb), iron (Fe) and cadmium (Cd). The efficiencies of the system implemented in Manaus/AM in terms of removing turbidity, TSS, Cu, Zn, Pb, Fe, and Cd were, respectively: 95.15%, 82.78%, 75.13%, 96.98 %, 65.68%, 71.82% and 100%. For the system evaluated in the Sagrado Coração de Jesus community, the efficiency in terms of removing turbidity, STS, Cu, Zn, Pb, Fe, Cd, N-NH4+, N-NO3-, N-NO2-, SO42- and P-PO43- were, respectively: 1th week (0%, 0%, 15.83%, 0%, 0%, 32.92%, 0%, 65.27%, 31.53%, 36.64% and 85.48%); 2th week (95.42%; 0%, 0%, 0% 0%, 7.89%, 22.27%, 70.98%, 71.58%, 28.73% and 0%); 3th week (43.13%, 49.02%, 92.27%, 0%, 0%, 43.47%, 96.63%, 91.03%, 55.48%, 18.75% and 54 .79%). For both CWCACF systems, total and thermotolerant coliforms remained present in the water after treatment, the potability in disagreement with current legislation. From the results obtained, it can be seen that during the initial period of operation, the CWCACF systems already showed good efficiencies in the removal of contaminants, in which it is observed that for the system installed in the Sagrado Coração de Jesus community, the system began to present better efficiency. As for potability, it appears that it is still not possible to obtain potable water through the CWCACF system, a determining factor is the presence of total and thermotolerant coliforms in the treated water, which, according to the legislation, must remain absent. However, given the results obtained, it is possible to observe that if there is a longer operating time of the installed systems, it is likely that there will be an improvement in the removal efficiency.