Avaliação do uso e eficiência de tratamentos domiciliares de água em comunidades rurais na Amazônia Central

Abstract

In the Amazon, most of the rural population lives in small and dispersed groups lacking essential services. The region has the world's greatest water availability of surface fresh water, but the population does not have quality water for consumption. The consumption of non-potable water is a health risk, and water treatment at home can be one of the sanitary barriers to protecting human, environmental, and animal Health. Residents of rural communities traditionally use techniques for water treatment, but their efficiency is unknown. Therefore, the research aimed to evaluate water use conditions in riverside communities in the Central Amazon and home treatment solutions to improve quality. The research was developed in three stages. The conditions of household water use were analyzed from a database of 3,285 households, referring to 2018, using descriptive statistics and simple correspondence analysis. Next, a cross-sectional field sample study was carried out on the efficiency of the water treatment methods. In the last stage, a longitudinal study was conducted to evaluate ceramic candle filters' efficiency, use, and applicability for water treatment in riverside communities. The research revealed that 71% of the riverside population does not have a water supply system. The main way of accessing water is rainwater harvesting. The existence of a water supply and access to well water are associated with larger communities (more than 17 households) and located in non-floodable areas. Home treatment is adopted by 90% of the population and the use of sodium hypochlorite is the main method. The use of hypochlorite in rainwater promoted disinfection in some samples. However, the dose used (1 mg/L) is lower than recommended. For river water, sedimentation and straining removed up to 22% of the turbidity, with values close to 40 UNT in the treated water. The increase in the number of bacteria recorded mainly in river water after sedimentation and straining (0.3 log increase in Escherichia coli – E. coli ) indicated the probable contamination of containers used for handling and storing treated water. Ceramic candle filters significantly (p<0.05) removed E. coli contamination (0.6 log removal) but were not able to reach the minimum quality standard in 96% of the samples evaluated. The three types of ceramic candles tested were statistically similar in removing E. coli and turbidity. The presence of colloidal silver in one of the candles did not result in greater microbiological efficiency. It is concluded that rainwater chlorination is a suitable option for riverside communities in the central Amazon in the current context, and other forms of household water treatment have limited efficiency. To be used effectively and safely to protect health, investments in treatment technology and, especially, in training and raising awareness among user families are necessary.