The addition of fluoride to the public water supply is a method used for reducing tooth decay. In this sense, the control of fluoridation is important for maintaining its efficiency and, at the same time, for avoiding the risk of fluorosis as a result of the consumption of water with excess of fluoride. The objective of this study was to evaluate the adequacy of fluoride levels in the water distributed to populations of the state of Goiás, Brazil. Towards this aim, 5,039 water samples collected between 2011 and 2013 in 225 municipalities of the state of Goiás were analyzed for fluoride level. The results were assessed with regard to season, type of water source and geographic location. Fluoride levels were found to vary between complete absence and 2.5 mg F/L, with 28.2% of the samples being between 0.6 and 0.8 mg F/L, and 39.1% between 0.55 and 0.84 mg F/L. The rainy season produced a greater number of atypical results and higher values than the dry period. The systems supplied by groundwater sources were shown to have a limited control of fluoride concentration compared to systems supplied by surface water sources. Lower concentrations of fluoride were found in samples collected in the North and East Mesoregions of Goiás, with less than 7.5% being between 0.6 and 0.8 mg F/L, which systems are mainly supplied by groundwater sources with fluoride addition. This is an Open Access article distributed under the terms of the Creative Commons Attribution License BY CC

Sanitary landfill leachate (LL) composition varies according to climate variables variation, solid waste characteristics and composition, and landfill age. Leachate treatment is essentially carried out trough biological and physicochemical processes, which have showed variability in efficiency and appear a costly solution for the management authorities. Electrocoagulation (EC) seems a suitable solution for leachate treatment taking into account the characteristics of the liquor. One of the problems of EC is the electrode passivation, which affects the longevity of the process. One solution to this problem could be the replacement of the electrode by one made of recyclable material, which would make it possible to change it frequently and at a lower cost. The objective of the present work was to evaluate the removal of heavy metals (As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se and Zn) and coliforms from a LL by EC using electrodes made from steel swarf (SfE) up to 8 h. Removal efficiencies of detected heavy metals were 51%(Cr), 59%(As), 71%(Cd), 72%(Zn), 92%(Ba), 95%(Ni) and >99%(Pb). The microbial load of coliforms in leachate was reduced from 10.76 × 104 CFU/mL (raw leachate) to less than 1 CFU/mL (after treatment with SfE) (i.e., approximately 100% reduction). The use of SfE in EC of LL is very effective in removing heavy metals and coliforms and can be used as alternative treatment solution for such effluents.

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The rate of attendance to sanitary sewage services is low in rural communities, representing precarious sanitation conditions with dumping in rudimentary cesspools or in the open. Knowledge of the fractions of effluents generated and the places where they are released is important, since inadequate disposal generates public health problems and negatively impacts the environment. In this way, the objective of this work was to identify the amounts of effluent fractions generated and the deficit of sanitary sewage in rural communities in the state of Goiás. The study area included 97 rural communities, from which data were collected regarding the existence of bathrooms, alternatives and disposal sites for domestic sewage fractions, such as feces separated from urine. The results indicated an absence of a bathroom in 6.6% of the analyzed rural households, being in 2.5 and 18.2% in the households of the settlements and quilombolas, respectively, highlighting in the latter the occurrence of disposal in the open or stream in 13.7%. There was a predominant use of rudimentary cesspools to receive sewage and fecal water, while gray water from the kitchen sink and washing tanks are mainly disposed in the backyard, representing the greatest deficit in the communities. Thus, in most of the studied households there is a deficit due to lack of service, due to the release of untreated effluents into ditches/open air, mainly for gray water, and precarious service due to the unsafe disposal of treated effluents or the use of rudimentary cesspools. Few alternative technologies were found for the treatment of effluents, with ecological pit, biodigester and Tapiocanga stone pit being identified. It was concluded that the deficit of sewage in the households of the studied communities is high, due to the release of effluents without treatment and the use of rudimentary cesspools, characterized as lack of service and precarious service, respectively, observed in 84.6% of households.