**Bioremediation of Polluted Waters Using Microorganisms**

Luciene M. Coelho, Helen C. Rezende, Luciana M. Coelho, Priscila A.R. de Sousa, Danielle F.O. Melo and Nívia M.M. Coelho

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/60770

#### **Abstract**

sired because of the insufficient performance or insufficient adaptability to various condi‐

This book discusses the recent advances in bioremediation of wastewater and polluted soil. In the first chapters of this book, respected researchers in this field describe how the optimi‐ zation of microorganisms, enzymes, absorbents, additives and injection procedures can help to realize excellent bioremediation. The general concept of bioremediation of polluted water is reviewed in chapter 1. In chapters 2–4, the utilization of Haloarchaea, Synechocystis and other microorganisms identified using metagenomics are introduced as effective reaction agents for bioremediation. Because bioremediation often occurs in specific environments, the selection of microorganisms which can actively work in said environments is a key fac‐ tor for optimal bioremediation. The contents of these chapters will assist the selection of mi‐ croorganisms for bioremediation. Moreover, in chapters 5–7, the authors discuss optimal biosurfactants for adsorption, enzymes for the degradation of dyes and the effects of addi‐ tives for bioremediation, respectively. The proper selection of absorbents, enzymes and ad‐ ditives is another key factor for optimal bioremediation. In the latter chapters, other respected researchers in this field introduce bioremediation processes that have been per‐ formed in the field. The eliminations of hexavalent chromium (VI) and organochlorine pesti‐ cides by fungi are introduced as concrete examples in chapters 8 and 9. Moreover, in chapters 10 and 11, phytoremediation of landfill soil and bioremediation of lead are dis‐

This book will be useful for those studying or developing new bioremediation processes and students studying environmental science and engineering. It will provide important infor‐ mation about recent advances in bioremediation and novel ideas for effective bioremedia‐ tion. Finally, I would like to thank Ms. Ana Pantar, Ms. Ivona Lovric and the publishing process managers of the InTech Publishing Group for their great support and assistance

> **Dr. Naofumi Shiomi** Kobe College, Japan

cussed, including novel methods for bioremediation.

throughout the writing and publication process of this book.

tions.

VIII Preface

Water pollution is an issue of great concern worldwide, and it can be broadly divided into three main categories, that is, contamination by organic compounds, inorganic compounds (e.g., heavy metals), and microorganisms. In recent years, the number of research studies concerning the use of efficient processes to clean up and minimize the pollution of water bodies has been increasing. In this context, the use of bioreme‐ diation processes for the removal of toxic metals from aqueous solutions is gaining considerable attention. Bioremediation can be defined as the ability of certain biomolecules or types of biomass to bind and concentrate selected ions or other molecules present in aqueous solutions. Bioremediation using microorganisms shows great potential for future development due to its environmental compatibility and possible cost-effectiveness. A wide range of microorganisms, including bacteria, fungi, yeasts, and algae, can act as biologically active methylators, which are able to at least modify toxic species. Many microbial detoxification processes involve the efflux or exclusion of metal ions from the cell, which in some cases can result in high local concentrations of metals at the cell surface, where they can react with biogenic ligands and precipitate. Although microorganisms cannot destroy metals, they can alter their chemical properties via a surprising array of mechanisms. The main purpose of this chapter is to provide an update on the recent literature concerning the strategies available for the remediation of metal-contaminated water bodies using microorganisms and to critically discuss their main advantages and weaknesses. The focus is on the heavy metals associated with environmental contamination, for

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instance, lead (Pb), cadmium (Cd), and chromium (Cr), which are potentially hazardous to ecosystems. The types of microorganisms that are used in bioremedia‐ tion processes due to their natural capacity to biosorb toxic heavy metal ions are discussed in detail. This chapter summarizes existing knowledge on various aspects of the fundamentals and applications of bioremediation and critically reviews the obstacles to its commercial success and future perspectives.

**Keywords:** Metals, microorganisms, bioremediation, polluted water
