Zeolites are crystalline aluminosilicates, three-dimensional, microporous, based on framework structure with a rigid anion, with well-defined channels and cavities. These cavities contain exchangeable metal cations (Na+, K+, etc.) And can also retain removable and replaceable guest molecules (water in natural zeolites). To date about 40 have been characterized structures of natural zeolites and have developed more than 130 synthetic structures. The most important natural zeolites are analcime, chabazite, clinoptilolite, erionite, ferrierite, heulandite, laumontite, and phillipsite mordonita [58].

Zeolites are composed of aluminum, silicon, sodium, hydrogen and oxygen. The crystal structure is based on the three network addresses with SiO4 tetrahedral shaped with four oxygens shared with adjacent tetrahedra. The physical properties unique aspects provide for a wide variety of practical applications. Figure 4 shows the basic structure of the zeolite tetrahedral [63].

The physical properties of the zeolite are that they possess features bright, hardness and wear resistance. Applications of natural zeolites make use of one or more of its chemical properties, usually including adsorption, ion exchange and catalysis. These properties are a function of the crystal structure of each species, cationic structure and composition [63].

Clinoptilolite is from the zeolite minerals are best known for its uses and applications. It is a natural zeolite formed from volcanic ash in lakes and marine waters millions of years ago. Clinoptilolite, is the most studied and is considered more useful, since it is known as an adsorbent of certain toxic gases such as hydrogen sulfide and sulfur dioxide. In fact few countries that have had deposits in operation, including: Japan, Italy, USA, Russia, Hungary, Bulgaria, Cuba, Yugoslavia and Mexico [39]. Recognizes the capacity of the zeolites natural adsorb heavy metals and other contaminants from water. In certain cases, it requires a pretreatment of the zeolite to modify or improve its adsorption properties [62].

5. Conclusion

This chapter has provided the results of research of aerobic and anaerobic biomass in the batch and continuous system using a support for the biomass: silica, polyacrylamide gel, polyurethane, calcium alginate, glutaraldehyde, charcoal and zeolites. The use of support for the biomass increases the development of the microorganisms. Also describes the affecting parameters: time, pH, temperature, HRT, toxicity and stirring speed. Also in this chapter describe the techniques for determination of parameters for anaerobic such as, chemical oxygen demand (COD), alkalinity, methane production, total solids (TSS), volatile solids (VSS), volatile fatty acids (VFA) concentrations, and for the aerobics, the biomass concentration using % of transmittance, McFarland nephelometer, isolation, macroscopic and microscopic characterization, growth kinetics, in batch and continuous system.

Author details

Onofre Monge Amaya, Maria Teresa Certucha Barragan and Francisco Javier Almendariz Tapia

University of Sonora, Department of Chemistry and Metallurgy. Hermosillo, Sonora. Mexico

Acknowledgement

This work was made possible through support provided by the University of Sonora, through the Department of Chemical Engineering and Metallurgy, and Engineering Division. The authors would like to thank: The National Council for Science and Technology (CONACyT), well as students Gisel Figueroa, Gonzalo Figueroa, Guadalupe Lopez, Karla Hernandez, Hiram Banuelos, Carlos Jaramillo, Luis Carlos Platt, Axel Valenzuela, Glenda Duarte.