Special Issue "Advances in Bioseparation Engineering"

Guest Editor
Prof. Dr. Kostas A. Matis
Laboratory of General and Inorganic Chemical Technology, Department of Chemistry, Aristotle University, GR-541 24 Thessaloniki, Greece
Website: http://users.auth.gr/kamatis/
E-Mail: kamatis@chem.auth.gr
Phone: +30 2310 997743
Fax: +30 2310 997836
Interests: separation science and technology (flotation); wastewater treatment; environmental biotechnology; inorganic materials; mineral processing

Guest Editor
Dr. George Z. Kyzas
Laboratory of General & Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Website: http://kyzas.wordpress.com
E-Mail: georgekyzas@gmail.com
Phone: +30 6947 994624
Interests: removal of pollutants from aqueous waste waters; synthesis of adsorbents; characterization of materials; adsorption and transportation phenomena

Dear Colleagues,

Bioprocesses are known to treat raw materials and thereby generate useful products [1]. The individual operations, or even steps within a process which change or separate components, are called unit operations. For instance, in a typical fermentation process, raw materials are altered significantly by reactions occurring in the reactor. Nevertheless, before and after fermentation, physical changes are carried out that are important in order to prepare materials/substrates for the reaction, and also to extract and purify the desired product(s) from the culture broth.

The concept of unit operations embodies many different methods of separating mixtures and hence, represents a major advance in chemical technology. Over time, however, those and subsequent concepts have evolved into a unified field of separation processes; certainly, there are several major gains in gaining insight into the capability and efficiency from viewing separation processes as a unified field [2]. In this regard, sustainability in this field and its significance for the chemical and process industry has been recently examined [3]. We would be very pleased to receive your valuable contributions in this field.

References
1.     Doran, P.M. Bioprocess Engineering Principles; Academic Press: Sydney, Australia, 1998.
2.     King, C.J. From unit operations to separation processes. Sep. Purif. Methods 2000, 29, 233.
3.     Peleka, E.N.; Matis, K.A. Water separation processes and sustainability. Ind. Eng. Chem. Res. 2011, 50, 421.

Prof. Dr. Kostas A. Matis
Dr. George Z. Kyzas
Guest Editors

Submission

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• bioprocesses
• cell harvesting
• recovery of biomolecules
• membrane-based separations
• purification of water
• adsorption
• extraction
• process development

Type of Paper: Review
Title: Flotation of Biological Materials
Authors: George Z. Kyzas ^1,2 and Kostas A. Matis ^2,*
Affiliations: ¹ Department of Oenology and Beverage Technology, Technological Educational Institute of Kavala, GR-654 04 Kavala, Greece; E-Mail: georgekyzas@gmail.com;
² Division of Chemical Technology & Industrial Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece; E-Mail: kamatis@chem.auth.gr
Abstract: Flotation constitutes a gravity separation process, which originated from the minerals’ processing field; however, it has nowadays found several other applications, as for example in the wastewater treatment field. Concerning the necessary bubble generation method, typically dispersed-air and/or dissolved-air flotation were mainly used. In the former generation technique, usually electro-flotation is classified, too. Various types of biological materials were tested and floated efficiently, such as bacteria, fungi, yeasts, grape stalks, activated sludge, etc. Innovative processes have been studied in our Laboratory, particularly for metal ions removal, involving the initial abstraction of heavy metal ions onto a sorbent (including a biosorbent): in the first process, the application of a flotation stage followed for the efficient downstream separation of metal-laden particles. The ability of microorganisms to remove metal ions from dilute aqueous solutions (as most wastewaters are) is a well-known property. The second separation process, applied effectively, was a new hybrid cell of microfiltration combined with flotation. A large number of techniques have been used today to limit the membranes fouling and among them, certainly is air bubbling, constituting also the transport medium in flotation

Type of Paper: Review
Title: Selective Biosorbents: Recent Bioengineering Insights
Authors: George Z. Kyzas ^1,2,*, and Kostas A. Matis ²
Affiliations: ¹ Department of Petroleum and Natural Gas Technology, Technological Educational Institute of Kavala, Kavala GR–654 04, Greece; E-Mail: georgekyzas@gmail.com; ² Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR–541 24, Greece; E-Mail: kamatis@chem.auth.gr
Abstract: Many researchers have studied the biosorption of different pollutants. However, a limited number of works focus on selectivity, which is characterized as a specific property for each biosorbent. Selective biosorption can be achieved via a special synthesis technique (namely Molecular Imprinting). The design of modern biosorbents is based on two properties/abilities: (i) the biosorption capacity presented, and (ii) the selective ability to recognize and biosorb/bind target molecules among different pollutants. This idea was applied through Molecular Imprinted Polymers (MIPs). The history of molecular imprinting traces back to the 1940s and 1950s, when there was impetus to create an affinity for dye molecules in silica gel, which is considered to be the first imprinted material. MIPs represent a new class of materials (known as non-conventional adsorbents) that have artificially created receptor structures. Specifically, published literature has mainly focused on the application of MIPs in analytical fields; such applications include the separation of enantiomers, binding assays, sensors, etc. Furthermore, the development of MIPs for solid-phase extraction (SPE) has been extensively reported in the areas of food and pharmaceuticals analysis, including their use as selective sorbents for the extraction (or clean-up) of different classes of compounds from various complex matrices. However, until recently, there has been a gap in the literature: there are only a limited number of works addressing bioengineering’s contributions to the development of selective biosorbents. In this review article, the focus is on such recent developments in bioengineering. Kinetic and bioengineering models were reviewed highlighting some crucial parameters that affect selectivity. As model pollutants, some industrial-type compounds were used as dyes, metals, phenols, drugs, pesticides, insecticides, etc. In this review, a critical analysis of bioengineering’s contributions to the development of selective biosorbents describes said biosorbents’ characteristics, advantages, and limitations, and discusses the various bioengineering mechanisms involved.
Keywords: selective biosorbents; molecular imprinting; bioengineering models; environmental pollutants

Type of Paper: Review
Title: Biofouling Issues in Membrane Separations: Major Mechanisms and Preventive-control Strategies
Authors: Petros K. Gkotsis ¹,*, Dimitra Banti ², Efrosini N. Peleka ¹, Anastasios I. Zouboulis ¹ and Petros E. Samaras ³
Affiliations :
¹ Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece; E-mails: petgk@chem.auth.gr (P.K.G); peleka@chem.auth.gr (E.N.P.); zoubouli@chem.auth.gr (A.I.Z.)
² Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece; E-Mail: mpanti@food.teithe.gr
³ Department of Food Technology, Alexander Technological Educational Institute of Thessaloniki, 57400, Thessaloniki, Greece; E-Mail: samaras@food.teithe.gr
Abstract: Membrane fouling is one of the most important considerations in the design and operation of membrane systems as it affects pretreatment needs, cleaning requirements, operating conditions, cost and performance. Given that membrane fouling represents the main limitation to membrane process operation, it is unsurprising that the majority of membrane material and process research and development conducted is dedicated to its characterization and amelioration. With specific regard to filtration in Membrane Bioreactors (MBR), it is widely recognised that the main foulants are the extracellular polymeric substances (EPS) and microbial products excreted by microorganisms. Filtration proceeds according to a number of widely recognized mechanisms which comprise complete, standard or intermediate blocking and cake filtration. Over the last few years several strategies have been employed to control membrane biofouling, such as pretreatment of the feedwater, membrane aeration or application of physical and chemical protocols. However, frequent membrane replacement results in higher operating cost and, thus, limits the widespread implementation of MBR suggesting that membrane biofouling still remains a major issue. Relatively recent developments involve the construction of anti-fouling membranes, the modeling of membrane biofouling by mathematical approaches and the application of ultrasound, ozone and electric field to control membrane biofouling.
Keywords: membrane biofouling; biofouling control strategies; membrane bioreactors