Green Adsorbents

Foreword

When Dr. Kyzas asked me to write this preface, I was honored and thrilled to have the opportunity to introduce this outstanding work!

I have been impressed with the promising career of Dr. Kyzas who has contributed enormously in the field of environmental technology and in particular adsorption phenomena. He has both published extensively on this subject and is well qualified to write and edit such books. Dr. Kyzas has made significant contributions in the synthesis and adsorptive evaluation of various materials during his early research career. The research potential of Dr. Kyzas is really impressive. The high-level of his research includes: (i) publication of many papers in highly Impact Factor scientific journals; (ii) oral or poster presentation in National and International Scientific Conferences; (iii) publication of many chapters in scientific books; (iv) editorship in Scientific journals; (v) reviewership in Scientific journals. However, the most impressive thing in his early scientific research career is that until the end of his Ph.D. he had published 6 papers, while the next 5 years took off his research capabilities, publishing 52 papers in high Impact Factor journals. Taking into account (i) his age; (ii) his teaching work (until now) as a.Lecturer at Technological Educational Institute of Kavala (Greece); (iii) the impressively rapid growth of his research career in a relatively young age, I can assure that Dr. Kyzas can be easily considered as one of the topranked young scientist of Greece.

The book is very well organized in multiple short chapters that are beautifully illustrated both with ultrasound images and diagrams. Initially, they introduce the subject with a chapter on the different compositions of industrial wastewaters. Next, adsorption (as the major treatment of wastewater) is presented, which is a simple, rapid, and economic decontamination technique. This technique is also described in this eBook both in batch mode examples and fixed-bed ones. The following chapters introduce the synthesis of various materials used as adsorbents. These are environmental-friendly materials satisfying some basic standards of the general field of “green technology”. Examples of polluatnts removed from wastewaters with green adsorbents are then presented as dyes, heavy metals (ions), pesticides, phenols, insecticides etc. The last chapters report some useful information which can be characterized as real and practical regarding technoeconomical data for the use of green adsorbents. Industrial scaling and economic perspectives are posed along with the future trend of green adsorption technology.

This book, while very comprehensive, remains simple in its approach. It makes a very complex and rather intimidating organ accessible to both the novice and the seasoned examiner. Furthermore, this book is presented as an eBook which is a very innovative format, awaited with great anticipation. Such novel media will challenge the primacy of bulky printed books. Many books will soon be available as eBooks and carried as a small discrete thumb-drive or even downloaded perhaps on an electronic device. Electronic versions of books are the future of our industry and Dr. Kyzas has stepped up in choosing such a modern and practical display for his book.

In conclusion, I am very excited about this eBook, not only because it is superbly organized and is well illustrated, but also because as an eBook it can be carried and propagated throughout our community much more easily than a hard copy book. Dr. Kyzas has succeeded admirably in their endeavor to produce what promises to be an outstanding resource on “Green Adsorption” technology.

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Preface

One of the most recent trends in environmental technology is the research turn to green chemistry. It is generally accepted that one of the most promising techniques for wastewaters treatment is adsorption. On this basis, numerous adsorbent materials have been synthesized up to now. However, nowadays, there is a novel concept, which promotes the use of materials with the lowest possible cost. The economic crisis of the 2000s led researchers to turn their interest to adsorbent materials with lower cost. Attempts were already realized to use some low-cost adsorbent materials in order to initially treat synthetic aqueous solutions and then real industrial samples. In this eBook, the main scope is to describe these environmental-friendly materials namely “green adsorbents”, as I firstly introduce this term. With this term, it is meant the adsorption process using low-cost materials originated from: (i) agricultural sources and by-products (fruits, vegetables, foods); (ii) agricultural residues and wastes; (iii) low-cost sources from which most complex adsorbents will be produced (i.e., activated carbons after pyrolysis of agricultural sources).

It is a fact that low-cost adsorbent materials belong to a hot-topic of recent literature given its economic perspective. Although they present a slightly lower adsorption capacity compared to more complex materials (i.e. polymers), their near zero cost of preparation makes them very attractive in chemical technology. In this field, some crucial factors will be developed regarding the removal of those environmental pollutants from aqueous systems with the aforementioned type of materials.

Three main categories of environmental pollutants are discussed as: (i) dyes; (ii) heavy metals, and (iii) others (phenols, pesticides/insecticides etc). This category will be preferred to be presented as general category of “others”, because the number of published works for this type of pollutants is still limited compared to those of dyes or metals.

Extensive comparison will be done for: (i) their adsorption capacity, showing the main models used up to now for the expression of their theoretical maximum capacity theoretically; (ii) their kinetic behavior, showing the main models used and some more specific kinetic simulations; (iii) parameters influenced by adsorption (salinity, particle size or mass of adsorbent etc); (iii) their reuse potential, given the ultimate goal of each adsorbent to be used in industrial/factorial design; (iv) fixed-bed columns; (v) the surface of those low-cost materials (comments about their characterization); (vi) economic perspectives; (vii) future trends and applicability.

List of Contributors