Nitrifying and Denitrifying Microbiological Mud Encapsulated by the Sol–Gel Method

The aquatic underground mantle in the Peninsula of Yucatan (Mexico) represents the only source of water supply for domestic consumption. Nevertheless, this mantle is extremely vulnerable to infiltration of pollutants as nitrates due to the karstic layer. Nitrates are inorganic pollutants, whose mobility and stability make them highly dangerous in aerobic systems such as underground water. This contaminant has been found at up to 223 mg/L in artesian wells, whereas the maximum limit permitted by the World Health Organization is 45 mg/L. The development of innovative biomaterials, as nitrifying and denitrifying microbiological mud encapsulated in an inert matrix using the sol–gel technique, represents a possible alternative to eliminate nitrates in situ from the underground water of Merida in the state of Yucatan, Mexico. The sol–gel method has been extensively used for the preparation of such materials permitting a higher stability and viability of useful organisms. In this work the thermal properties of nitrifying and denitrifying mud encapsulated in silica gel derived from tetraethoxysilane are presented as a function of temperature. The photopyroelectric technique was used to study how different types of mud interchanges heat with the environment. The specific surface area of the nitrified mud was determined by analyzing the pore size distribution.