The present study performed a qualitative and quantitative characterization of the raw sewage collected at the entrance of the sewage treatment station of the city of Itumbiara, state of Goiás. Samples were collected every two hours over a period of seven consecutive days. Characterization of both point samples and composite samples was performed. The parameters analyzed were: temperature, pH, alkalinity, chemical oxygen demand, oil and grease, electric conductivity, total phosphorus, settleable solids, ammoniacal nitrogen, total suspended solids, volatile suspended solids, fixed suspended solids and turbidity. These results allowed us to verify that it is possible to perform the collection and analysis of a point sample, instead of a composite sample, as a way of monitoring the efficiency of a sewage treatment plant.
Facing the growing demand for water, discussions on environmental sustainability and conservation of this resource have become increasingly important. Among the possibilities for water conservation, air conditioning systems have potential applicability because, during their operation, water is generated via the condensation of air humidity, which is normally discarded. Thus, the objective of this work was to evaluate the water released by air conditioning equipment (condensed water) installed in the Laboratory of Water Analysis (LAnA) qualitatively and quantitatively, in order to verify its potential for use in the laboratory itself. For this, the quality of the water produced by three air conditioners was compared water quality parameters found in the literature, as well as with water produced by a distiller and an ultra-purifier, both used in the LAnA. Water quality was evaluated using physicochemical parameters (i.e. pH, electrical conductivity, resistivity, alkalinity, turbidity, apparent color and hardness) and microbiological parameters (i.e. total coliforms, Escherichia coli and heterotrophic bacteria). The average water flow produced by the three monitored air conditioners was 3.08 L/hour, which is higher than the daily consumption by the LAnA, indicating that its use would be quantitatively propitious. The physicochemical and microbiological analyses found that, condensed water can be used in the routine activities of LAnA. However, for its use as reagent-grade water, a prior treatment would be necessary, mainly due to the presence of heterotrophic bacteria.
The preferred data for analyzing water availability are those of historical flow series of the sources of interest; however, most Brazilian watersheds do not have sufficient fluviometric monitoring. Such cases require techniques for transposing data from one region to another, otherwise known as ‘flow regionalization’. The present work aimed to compare the method proposed by Secretaria de Meio Ambiente e Desenvolvimento Sustentável (SEMAD) of the state of Goiás with the traditional method of regionalization for determining reference flow at the mouth of the surface catchment basin of the Meia Ponte river. Data from eight fluviometric stations were used for regionalization, with the regression equations being adjusted using four different models. The result revealed that the potential and linear models performed the best, both with R2 and R2a values of 0.996 and 0.995, respectively. The relative error in the application of the potential model and of the method adopted by SEMAD were below 30%. The reference flows obtained by the two best performing methods differed, with flow determined by the traditional method being 5.93% lower than that of the SEMAD equation. Therefore, a more detailed study is recommended to determine which equation models better fit the region.
Freshwater is an essential natural resource for humanity, however, its quality has been compromised as a result of natural and anthropogenic interference. The objective of the present study was to determine the Bascarán Water Quality Index (WQIB) for the Tamanduá stream in the municipality of Aparecida de Goiânia, Goiás, Brazil, and relate it to the limits established by CONAMA resolutions nº 357  and nº 274 , for Class 2 freshwater bodies. The study was carried out at three sampling points proximate to urban parks, with samples collected in both the dry and the rainy seasons with the measurement of flow. The physical, chemical and biological parameters were analyzed as recommended in Standard Methods . Parametric descriptive statistics were used for data analysis. The WQIB results classified the water as acceptable (24%), normal (48%), improper (20%) and unpleasant (8%), with turbidity, DO and total coliforms responsible for decreased WQIB in the rainy season. The parameters pH, apparent color and DO do not conform with CONAMA resolution nº 357  while water resources for bathing were classified as excellent according to CONAMA resolution nº 274 .