Chapters authored
Short-Cut Methods for Multicomponent Batch Distillation
This work present the batch distillation shortcut methods developed from the Fenske-Underwood-Gilliland (FUG) method of continuous distillation. In addition, a comparison between the results of shortcut method developed by Diwekar and Narváez-García et al. is done. The results of both methods are compared for validation with the results using the rigorous method presented by Domenech and Enjalbert. The results indicate no significant differences in both shortcut methods being the maximum deviation found between the two shortcut methods is less than 3%. Then, the use of any of both methods is in the ease or difficulty of the solution each of the model equations. Both methods were implemented using Fortran programming. Multdistbatch© software was used for the rigorous method.
Part of the book: Distillation
Potential Production of Ethanol by Saccharomyces cerevisiae Immobilized and Coimmobilized with Zymomonas mobilis: Alternative for the Reuse of a Waste Organic
Fermentation technologies have been developed to improve the production of ethanol and an alternative is the immobilization technology, which offers the possibility of efficiently incorporating symbiotic bacteria in the same matrix. This study analyzes the potential use of immobilized and coinmobilized systems on beads of calcium alginate for ethanol production used mango waste (Mangifera indica) by Zymomonas mobilis and Saccharomyces cerevisiae compared with free cells culture and evaluate the effect of glucose concentration on productivity in coimmobilized system using a Chemostat reactor Ommi Culture Plus. For free cell culture, the productivity was higher for Z. mobilis (5.76 g L-1 h-1) than for S. cerevisiae (5.29 g L-1 h-1); while in coimmobilized culture, a higher productivity was obtained (8.80 g L-1 h-1) with respect to immobilized cultures (8.45 g L-1 h-1 - 8.70 g L-1 h-1). The conversion of glucose to ethanol for coimmobilized system was higher (6.91 mol ethanol) with 50 g L-1 of glucose compared to 200 g L-1 of glucose (5.82 mol ethanol); suggesting the immobilized and coimmobilized cultures compared with free cells offer an opportunity for the reuse of organic residues and high alcohol production.
Part of the book: Yeast
Effect of Hydrodynamic Conditions of Photobioreactors on Lipids Productivity in Microalgae
This research presents the effect of hydrodynamic conditions at different rates of aeration (1.4, 1.8, and 2.3 vvm) and the geometry of two photobioreactors with internal lighting on lipid productivity and other parameters of Chlorella vulgaris. A two-step nitrogen-reduction cultivation mode was applied for promoting lipid accumulation. The inoculum was cultivated initially at 90 mg L−1 N-NH4+, and at the end of the exponential phase, it was fed to 11 L photobioreactor at 20 mg L−1 of N-NH4+. The results showed that with similar aeration rates, the hydrodynamic regime in both photobioreactors was different. However, the increase in shear rate and agitation did not cause cell damage or photoinhibition. The maximum cell growth was 12 × 106 cells mL−1. The highest consumption of nitrogen was 19% and shear rates were of 120-340 s−1. The highest lipid productivity was reached in bubble column at 1.8 vvm with 0.650 mg·L−1 d−1.
Part of the book: Microalgal Biotechnology
Heavy Metal Contamination in a Protected Natural Area from Southeastern Mexico: Analysis of Risks to Human Health
In this chapter, a little of the history of Carmen City, Mexico is addressed; this island is immersed in a Protected Natural Area and in the “Campeche Sound” an oil extraction site. Fishing natural resources were for many years the pillar of the development of the area; the most commercially important species are still shrimp, oysters and scales. Nowadays, although the volumes of capture have decreased considerably, different species of high commercial value are still extracted. The considerable development of the oil industry has brought with its economic development and a better quality of life for its inhabitants; however, the ravages of pollution, rapid population growth, and deforestation have been the unwanted factor. This chapter addresses the effects of heavy metals on human health through a risk analysis, based on the criteria of the US Environmental Protection Agency (USEPA) that was carried out for different commercial species based on carcinogenic factors and not carcinogenic; the results show that the risk from consumption of these species is “potentially dangerous” for human health, especially in those species that, due to their eating habits (mollusks, bivalves, clams) tend to bio-accumulate heavy metals, such as cadmium, which it has been considered by the International Agency for Research on Cancer (IARC) as a risk factor; for this reason, the importance of periodically evaluating and monitoring oyster extraction banks, clams and, in general, all fishery products. Mexican legislation and various international legislations dictate the maximum permissible and tolerable levels of heavy metals in fishery products; the organisms considered in this study exceeded the permissible limits in copper and nickel, which represents a risk for human consumption.
Part of the book: Heavy Metals
Quantification of Heavy Metal Levels in Sediments of the “Palizada” River in a Protected Natural Area of Southeastern Mexico
This chapter shows the results of the determination of the levels of Copper (Cu), Iron (Fe), Magnesium (Mg), Manganese (Mn), and Cadmium (Cd) in sediments of the “Palizada River”; evaluated by atomic absorption. The results show high levels of Fe, Mg, and Mn concerning previous studies and are directly related to agricultural and livestock activities in the area. The metal-metal correlation analysis show significant values, suggesting that the generation source is the same. Some of the pollutants produced by industrial or population centers; end up in natural water bodies; by different physical processes, such as precipitation, complex formation, and others. These contaminants can bioaccumulate in aquatic organisms and reach humans through the food chain. Certain heavy metals such as cadmium (Cd) produced by human activities have been found in the oceans and the tissues of different organisms; which constitutes a risk for consumption; Cd is classified as an element that predisposes to the presence of Cancer. Therefore, the study of sediments is fundamental for determining the degree of contamination of an ecosystem.
Part of the book: Environmental Impact and Remediation of Heavy Metals
Purification of Rainwater Using a Photocatalysis Technique to be Applied to Communities in Ciudad del Carmen, Campeche, Mexico
View all chaptersSmall communities far from the municipal seat do not have access to drinking water, so many children suffer from various gastrointestinal diseases, which cause these children to grow up with nutritional deficiencies. In the state of Campeche, there are 300 sunny days. This energy can be used to install water treatment systems to make it drinkable. Therefore, a treatment system with heterogeneous photocatalysis was proposed using a zinc oxide catalyst doped with silver nanoparticles. The reactor has a metal structure with a flat plate where clay plates support the catalyst. Samples were taken every 2 h to carry out the corresponding analyses and in a period of 8 h of reaction. For the characterization of rainwater adhered to Mexican regulations. The results showed that there was 6400 NMP/100 mL for fecal coliforms at the beginning, and after 4 h, this parameter goes to <2 NMP/100 mL. Initially, the same happened for fecal coliforms; 9200 NMP/100 mL was determined. After 4 h, this parameter drops to <2 NMP/100 mL. The same behavior was observed with chlorides, hardness, and total alkalinity, which showed a tendency to decrease significantly. This confirms that the system works properly to eliminate organic compounds and purify rainwater.
Part of the book: Water Purification