Biosorption of Metals: A Complete Handbook
About this Book
The concept of adsorption is well known over a century. However, only recently the potential of biological materials to adsorb various ions/molecules even in their inactive/dead form have been identified. This process of adsorption termed “biosorption” has attracted several researchers to invest their time and skill. As a result of this, several biosorbents of different genera were identified as potent biosorbents for various metals, dyes and other organic pollutants. Being environmental-friendly as well as cost-effective, biosorption has several advantages over conventional adsorbent such as activated carbon. However, it should be emphasized that biosorption is still mostly lab-restricted technology and seldom applied for real wastewater treatment. Several factors hindered the application of biosorption to industrial wastewaters and this book, in addition to fundamentals, also aims to specify the constraints of biosorption and procedure to eradicate these limitations in real applications. Thus, this book is basically designed to provide (i) an up-to-date look at on-going experimental as well as theoretical activities in the field of biosorption; (ii) critical investigation to clear the prevalent misunderstandings and errors; and (iii) suggestion to transform the available knowledge into applications.
Chapter 1 introduces the readers to metals and their impact on environment as well as
Chapter 2 reviews conventional as well as recent techniques to treat metal-bearing wastewaters. Biological treatment methods such as bioprecipitation, bioaccumulation and phytoremediation (rhizofiltration, phytoextraction, phytostabilization and phytovolatilization) are discussed in detail with adequate literatures. Biosorption technique is introduced and its inherent advantages over other biological as well as conventional treatment methods are highlighted.
Chapter 3 summarizes performance of biosorbents towards various metal ions. The biosorbents taken into account in this chapter encompass various bacteria, fungi, micro-algae, macro-algae, industrial and agricultural wastes.
Chapter 4 discusses metal removal mechanism of biosorption process. The chapter includes various removal mechanisms suggested for different biosorbents. It also reviews various instrumental techniques used to elucidate biosorption mechanisms.
Chapter 5 reports various techniques used to prepare biosorbents for enhanced performance. Chemical pre-treatment, immobilization and genetic modification are discussed.
Chapter 6 lists batch experimental procedure of biosorption process. The influence of experimental parameters such as pH, temperature, biosorbent dosage, biosorbent size, initial solute concentration, ionic strength, agitation rate and contact time on biosorption performance was highlighted. This chapter also lists over 25 isotherm models and several kinetic models for description of biosorption experimental data. The errors associated with linearization of non- linear models are also highlighted with examples.
Chapter 7 explains continuous mode of biosorption process. The packed column biosorption process is discussed and the determination of parameters is detailed. Column models as well as important results are discussed as well.
Chapter 8 discusses scale-up of the biosorption process to industrial applications. Important aspects discussed in the chapter include, (i) behaviour of biosorbent in real solutions; (ii) applicability of biosorption to industrial wastewater treatment processes; (iii) process costs and overall scheme of biosorption; and (iv) development of practical biosorbent to suit real applications.
Chapter 9 suggests possible application of biosorption in other environmental technologies. It shows how to incorporate biosorbents into best management practices such as green roofs and biofilter with illustrations. Last but not at least,
Chapter 10 discusses scope and future directions of biosorption technology.