Efectos de productos calcáreos sobre diversos tipos de calidad de agua y tiempos de medición en ph y oxigeno disuelto

Abstract

In aquaculture, liming is mainly a means to neutralize acidity, the use of calcareous products is frequent, however, there is little information about their real and quantifiable benefits, which in many cases are not supplied in an adequate way, causing affectations in the balance of the different ecosystems and increasing production costs. The calcareous products currently on the market have different compositions and important properties that must be taken into account in practical applications. The two most important properties of limestone materials are the neutralizing capacity which establishes the amount of acid it can neutralize and its particle size which dictates the dissolution rate to neutralize the acidity. The following trial was conducted in order to know the type of interaction between calcium carbonate and calcium hydroxide on different types of water, depending on the pH and dissolved oxygen at different times, in order to know which combination of treatment between type of water and calcareous product is the best. A Completely Randomized Factorial Experiment was carried out, in which five experimental units were used, where one corresponded to the control. Four study factors were used: the type of water (fresh, salt and brackish water), the calcareous products (calcium carbonate and calcium hydroxide), the dose of carbonated product in grams (0.1; 0.2; 0.4; 0.8) and the time in minutes (0, 10, 30). To process the experimental design information, SPSS software was used to characterize the data distribution of the dependent variables, and the measures of tendency, central, dispersion and kurtosis were estimated. Since there was no interaction between the treatments of the study factors, a statistical analysis of the data of the effect of each treatment of the study factor individually (Types of Water, Dose, Moments or Carbonated Products) was carried out by means of intra-group factorial ANOVA. Finally, to determine the best treatment for pH and dissolved oxygen (mg/L) means, Post-Hoc Duncan Tests were performed.It was determined that there is interaction between the type of water and the calcareous product that was used as a function of pH, showing that the best treatment combination between the type of water and the calcareous product was Freshwater- - Ca〖(OH)〗_2with a pH of 8.57 of the water. No interaction was obtained between the type of water and the doses of the liming products, determining that the best doses were 0.8 g and 0.4 g with a mean water pH. 8.28 and 8.25, respectively. A similar case was obtained in the interaction between the type of water and the moment of measurement, it was concluded that the best moments of measurement for pH were 10 and 30 minutes. Finally, it was demonstrated that there is interaction between the type of water and calcareous product used as a function of the dissolved oxygen (mg/L) of the water, resulting in the best combinations of treatment between the type of water and the calcareous product is Freshwater- Ca〖(OH)〗_2 with a mean of 6.4, however it does not differ from the combination brackish water- Ca〖CO〗_3.