Characterization of Water Quality Indicators in the Micro-basin of the Arizona River, Atlántida (Honduras)

The water quality was studied in the basin of the Arizona River, supplier of the urban helmet of the municipality of Arizona, department of Atlántida (Honduras). In order to determine the quality of the water provided to the population. The methodology implemented consisted in carrying out tours in the area to obtain information on the delimitation, maps of land uses using tools of the geographic information system (GIS), then it was determined to assign the sampling sites for the three days for three months being the the following: take, storage tank and three taps of the urban center of the municipality of Arizona. The analytical parameters for the micro-watershed (site work) were evaluated and analyzed by the NSF ICA with a multivariate statistical analysis of principal component methods, the remaining analyzes were developed in comparisons according to the admissible values of the Standard Technique for the Quality of Drinking Water of Honduras 1995.


Introduction
Water is a natural resource of economic, strategic and social value, essential for the existence and well-being of the human being, as well as a good for humanity, useful for the maintenance of the planet's ecosystems (Uniagua, 2001). Given its importance for the development of life, and due to its unique characteristics, where no process occurs without direct and indirect action, it is essential that its presence in the environments an appropriate quality for its use (Rebouça, 2002).
Given that in recent years there has been a large population growth, thus diversifying the uses of water, have generated unwanted environmental conditions, such as the growth of the number of solid waste and other anthropogenic activities that accelerate the degradation of quality of water, being a worrisome situation, since according to the United Nations World Report on Water Resources Development in 2017 in Latin America only 8% of wastewater is subjected to some type of treatment.
In Honduras, there is a standard that regulates the quality control of drinking water, called the National Technical Standard for the quality of drinking water of July 31, 1995, where the methods of analysis are specified, as well as the frequency and number of samples required to establish the quality control and the evaluation of the different measurement parameters.
The microbasin of the Arizona River, is the object of study in this work, a river that is born in the community of Zanzibar (Honduras), running its course in a rugged topography with slope of 15-30% and influenced by the presence of broadleaved forests humid and presence of oxisolos with low fertility (Municipal Atlas and land cover, 2015), water quality indicators being studied in different points of the basin. jas.ccsenet.

Study A
The micro hectares ar 1 (

3) Disolved Oxygen
Dissolved oxygen (DO) is one of the most important water quality parameters, since it indicates the contamination of the same, being that the waters that present low values of DO, are caused by the presence of organic matter or material oxidized, demanding in these cases, a demand for oxygen, either for the respiration of microorganisms capable of digesting organic matter or to oxidize inorganic matter, being that such demand can exhaust or diminish the OD (Posada et al., 2013). It is a parameter that in water depends on the atmospheric pressure and the temperature of the water, according to Henry's law.
(4) Nitrates Nitrates, is the most stable form of nitrogen dissolved in water, whose concentration in natural waters is in concentrations of approximately 1.0 g L -1 (Shelton, 1999). Within the metabolism of ecosystems, nitrogen is the most important element, since it is related to the formation of proteins, one of the basic components of biomass.

(5) Total Phosphorus
Phosphorus is another element that leads to the determination of water quality, because when it is found in high concentrations in surface water, it leads to the eutrophication process, causing an increase in water turbidity (M. J. Hammer & M. J. J. Hammer, 2003).

(6) Total Dissolved Solids
The total dissolved solids parameter refers to the matter suspended or dissolved in water, that is, a parameter that measures the total filterable solid waste through a membrane of 2.0 μm. This parameter is decisive for the quality of the waters, since when there are waters with a high concentration of total solids, they generate bad taste for the palate and induce an adverse reaction for the consumer. This parameter is at the same time an indicator of the effectiveness of biological and physical wastewater treatment processes.

(7) Turbidity
Turbidity is another of the relevant analytical parameters in water quality, since it is a parameter that reflects the quantity of colloidal, mineral and organic materials, indicating the presence of contamination (Espigares & Fernández-Crehuet, 1999). In water for human consumption, high levels of turbidity, can protect microorganisms from the effects of disinfection, stimulating the proliferation of bacteria and, accordingly, increase the demand for chlorine. Other substances that increase turbidity in water are the presence of humic substances or heavy metals in water (Macó et al., 2004).

Biological Parameters Analyzed
Regarding the biological parameters determined were thermotolerant coliforms and biochemical oxygen demand (BOD).
(1) Thermotolerant Coliforms Thermotolerant coliforms, also known as fecal coliforms, encompass the species of bacteria found in the intestinal tract of both humans and warm-blooded animals, and can be differentiated into total and fecal coliforms (Silva et al., 2006). In water, it is an important parameter to evaluate the deficient hygienic-sanitary conditions, since this type of bacteria, is constituted by bacteria like Escherichia coli.
(2) Biochemical Oxygen Demand (BOD) The chemical oxygen demand (COD) is one of the most important biological indicators to determine the quality of drinking water, being used as a measure of the amount of oxygen required for the oxidation of biodegradable organic matter, present in the water sample. action of aerobic oxidation (Ramalho, 2003). It was determined at incubation temperature of 20 °C, for 5 days, expressed as mg L -1 O 2 known as BOD 5 .

Formula Used for Determining the Water Quality Index of the Microbasin
Once the chemical and biological parameters were determined, they were introduced into the equation proposed by Brown et al. (1990), to determine the water quality index (ICA) of the National Sanitation Foundation (NSF), according to Equation (1): where, n = parameters; wi = relative weights of each parameter; qi = subscript of parameter i. Finally, the value obtained from the multiplicative weighted function is interpreted by the ICA classification proposed by Brown.

Results and Discussion
To evaluate the quality of the water, samples were taken from different points: the first point was at the construction site of the project, point number two in the storage tank, the third, fourth and fifth point, in faucets distributed in the South zone -This and South-West of the urban area of the municipality of Arizona and the last tap in the final part of the distribution network of the project. In Table 1, the values of the ICA are presented for the three samplings made in the Arizona River micro-basin, obtaining the mean value of 51.37. Depending on the value obtained in the ICA, it is necessary to carry out a type of treatment in the water or another, since for high values obtained from the ICA (90-100), it means that the water will need a lower treatment than others with values lower (50-90) in which they must be subjected to an additional treatment (Torres, Cruz, & Patiño, 2009) as is the case of the value obtained in this work, this being considered in accordance with ICA of the NSF as regular, having that to be carried out a purifying treatment for that water to be consumed. In accordance with Honduran legislation, in the national technical standard for drinking water quality in 1995, the temperature is within the limits established by this legislation that establishes that it must be between 18-30 ºC, with the temperature in this work of 22 ºC.
Regarding the pH value, the norm establishes that it should be between 6.5-8.5, being within the parameters. The value of turbidity, the norm establishes that it must be less than one, being in this work with values higher than those established, especially in the first reading whose value is 4.87 UNT. The high value for turbidity in the first reading, may be due to the presence of sediments from the upper part of the micro-basin caused by the opening of an access road to the community of Zanzibar.
The levels of nitrates in the water for human consumption, according to the norm, are established recommended concentrations of 25 mg L -1 , being the maximum tolerable value of 50 mg L -1 , and for this work, no detectable concentrations of nitrate were found in water, which may be due to the organic matter acting as an interferent.
For the biological parameters, the norm says that coliforms should not exist, being found in this work values superiors to the allowed ones, being able to be due to certain type of anthropogenic contamination.
In Table 2, the values of different parameters for taps and water storage tank are presented. Also the h overuse of the taps an significant board of th were drain As for the value of 1 number 3, this reason given that considerab The maxim exceed the concentrat The measu and the sam These resu temperatur influences

Statisti
In Figure 2 The there was no interference of organic matter in the sample, it was in that only sampling during the investigation that their presence was determined. In the (CP-2) with a 30.9% analysis of the variance describes that the Coliforms Thermotolerant had their lowest presence in ICA 3 of the month of February 2016, this low is attributed to the little sediment present in the Arizona River by the incidence of rains presented weeks after sampling. According to Brooks et al. (1991) The presence of thermotolerant coliforms in surface waters is directly related to the presence of sediments due to runoff from rains or other spills or anthropogenic activities. The temperature did not show significant variability during the three samplings was maintained in the average levels

Conclusions
According to the land use map of the micro-basin, it is evidenced mainly in the upper and middle part, that vocation lands that produce water, are being used for grazing and coffee growing activity that causes: deforestation, soil erosion and consequently, water pollution.
The most influential types of pollution in the water quality of the "new" project in Arizona are: bacteriological and the increase in turbidity is due to the anthropogenic activities carried out in the upper and middle part of the micro-basin, which influence the erosion of large amounts of sediment in the riverbed as a result of excessive deforestation in the micro-basin.
According to the results presented by the ICA of the NSF, in reference to the water quality of the work, the "new" project of the Arizona river micro-basin is regular with an index of 51.37.