Sustainable Waste-to-Energy Technologies: Bioelectrochemical Systems

The food industry produces a large amount of waste and wastewater, of which most of the constituents are carbohydrates, proteins, lipids, and organic fibers. Therefore food wastes are highly biodegradable and energy rich. Bioelectrochemical systems (BESs) are systems that use microorganisms to biochemically catalyze complex substrates into useful energy products, in which the catalytic reactions take place on electrodes. Microbial fuel cells (MFCs) are a type of bioelectrochemical systems that oxidize substrates and generate electric current. Microbial electrolysis cells (MECs) are another type of bioelectrochemical systems that use an external power source to catalyze the substrate into by-products such as hydrogen gas, methane gas, or hydrogen peroxide. BESs are advantageous due to their ability to achieve a degree of substrate remediation while generating energy. This chapter presents an extensive literature review on the use of MFCs and MECs to remediate and recover energy from food industry waste. These bioelectrochemical systems are still in their infancy state and further research is needed to better understand the systems and optimize their performance. Major challenges and limitations for the use of BESs are summarized and future research needs are identified

Bioremediation: a novel approach to food waste management

Bioremediation is a general concept that includes all those processes and actions that take place in order to biotransform an environment, already altered by contaminants, to its original status. Although the processes that can be used in order to achieve the desirable results vary, they still have the same principles; the use of microorganisms or their enzymes, that are either indigenous and are stimulated by the addition of nutrients or optimization of conditions, or are seeded into the soil. There are several advantages of the implementation of such methods but mainly they have to do with the lack of interference with the ecology of the ecosystem. This article presents general bioremediation principles and techniques along with representative examples of their use both in the laboratory and industry and the ways that they work and give results in the five main areas of the food industry where bioremediation is applicable. Although the application of bioremediation to the food industry is not new, developments in microbiology and genetic engineering have given a valuable instrument to scientists to deal with contaminants in the environment. Pesticides, herbicides, insecticides, cleaning chemicals and chemicals used in the food chain are among the new contaminants which have entered the biogeochemical cycles. Bioremediating Methods transform the contaminants into substances that can be absorbed and used by the autotrophic organisms with no toxic effect on them. (C) 2002 Elsevier Science Ltd. All rights reserved

Microbial Consortia, a Viable Alternative for Cleanup of Contaminated Soils

The growth population and anthropogenic activity are constantly threatening the environment caused by the accumulation of different kinds of pollutants in the biosphere, especially in soils and sediments. Co-contaminated of environment with toxic organic and inorganic substance is often actually. For the remediation of soils contaminated with mainly petroleum, pesticide and heavy metals, several physical or chemical techniques have been developed inadequately. Inside the technologies "eco-friendly remediation", the bioremediation have emerged as an option using natural biological activity. Bioremediation are methods where microorganisms degrade one or various pollutants to non-toxic compounds, so working individually or coordinately inside a microbial consortium. A microbial consortium is the natural association of two or more microbial populations of different species, which act together in a complex system. The success of a bioremediation process with pure cultures is very low and restricted. Therefore, use of a microbial consortium appears to be more feasible and reliable. The chapter aims to review of the techniques for the elimination or degradation of pollutants using microbial consortia and highlight the importance of microbial consortia assessment. Also afford a discussion on the application of these techniques to the development of strategies and remediation policies.Fil: Villegas, Liliana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Martinez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Rodriguez, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Amoroso, Maria Julia del R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin