Biofilms--matrix-enclosed microbial accretions that adhere to biological or non-biological surfaces--represent a significant and incompletely understood mode of growth for bacteria. Biofilm formation appears early in the fossil record (approximately 3.25 billion years ago) and is common throughout a diverse range of organisms in both the Archaea and Bacteria lineages, including the 'living fossils' in the most deeply dividing branches of the phylogenetic tree. It is evident that biofilm formation is an ancient and integral component of the prokaryotic life cycle, and is a key factor for survival in diverse environments. Recent advances show that biofilms are structurally complex, dynamic systems with attributes of both primordial multicellular organisms and multifaceted ecosystems. Biofilm formation represents a protected mode of growth that allows cells to survive in hostile environments and also disperse to colonize new niches. The implications of these survival and propagative mechanisms in the context of both the natural environment and infectious diseases are discussed in this review.

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Bacterial biofilms: from the natural environment to infectious diseases.

Bacterial biofilms are formed by communities that are embedded in a self-produced matrix of extracellular polymeric substances (EPS). Importantly, bacteria in biofilms exhibit a set of 'emergent properties' that differ substantially from free-living bacterial cells. In this Review, we consider the fundamental role of the biofilm matrix in establishing the emergent properties of biofilms, describing how the characteristic features of biofilms - such as social cooperation, resource capture and enhanced survival of exposure to antimicrobials - all rely on the structural and functional properties of the matrix. Finally, we highlight the value of an ecological perspective in the study of the emergent properties of biofilms, which enables an appreciation of the ecological success of biofilms as habitat formers and, more generally, as a bacterial lifestyle.

Biofilms: an emergent form of bacterial life.

Principles and potential of the anaerobic digestion of waste-activated sludge

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

Removal of nutrients in various types of constructed wetlands.

This book has been produced to give a total overview of the Activated Sludge Model (ASM) family at the start of 2000 and to give the reader easy access to the different models in their original versions. It thus presents ASM1, ASM2, ASM2d and ASM3 together for the first time.

Modelling of activated sludge processes has become a common part of the design and operation of wastewater treatment plants. Today models are being used in design, control, teaching and research.

Contents 

This title belongs to Scientific and Technical Report Series 

ISBN: 9781900222242 (Print)

ISBN: 9781780402369 (eBook)

Activated sludge models ASM1, ASM2, ASM2d and ASM3 (in Japaneese)

Activated sludge models ASM1, ASM2, ASM2d and ASM3

The sharon process: an innovative method for nitrogen removal from ammonium-rich waste water

Organic matter must be removed from sewage to protect the quality of the water bodies that it is discharged to. Most current sewage treatment plants are aimed at removing organic matter only. They are energy-inefficient, whereas potentially the organic matter could be regarded as a source of energy. However, organic carbon is not the only pollutant in sewage: Fixed nitrogen such as ammonium (NH4+) and nitrate (NO3−) must be removed to avoid toxic algal blooms in the environment. Conventional wastewater treatment systems for nitrogen removal require a lot of energy to create aerobic conditions for bacterial nitrification, and also use organic carbon to help remove nitrate by bacterial denitrification (see the figure). An alternative approach is the use of anoxic ammonium-oxidizing (anammox) bacteria, which require less energy ( 1 ) but grow relatively slowly. We explore process innovations that can speed up the anammox process and use all organic matter as much as possible for energy generation.

http://science.sciencemag.org/content/sci/328/5979/702.full.pdf

Sewage Treatment with Anammox

For information on the online course in Biological Wastewater Treatment from UNESCO-IHE, visit: http://www.iwapublishing.co.uk/books/biological-wastewater-treatment-online-course-principles-modeling-and-design Over the past twenty years, the knowledge and understanding of wastewater treatment have advanced extensively and moved away from empirically-based approaches to a first principles approach embracing chemistry, microbiology, physical and bioprocess engineering, and mathematics. Many of these advances have matured to the degree that they have been codified into mathematical models for simulation with computers. For a new generation of young scientists and engineers entering the wastewater treatment profession, the quantity, complexity and diversity of these new developments can be overwhelming, particularly in developing countries where access is not readily available to advanced level tertiary education courses in wastewater treatment. Biological Wastewater Treatment addresses this deficiency. It assembles and integrates the postgraduate course material of a dozen or so professors from research groups around the world that have made significant contributions to the advances in wastewater treatment. The book forms part of an internet-based curriculum in biological wastewater treatment which also includes: * Summarized lecture handouts of the topics covered in book * Filmed lectures by the author professors * Tutorial exercises for students self-learning Upon completion of this curriculum the modern approach of modelling and simulation to wastewater treatment plant design and operation, be it activated sludge, biological nitrogen and phosphorus removal, secondary settling tanks or biofilm systems, can be embraced with deeper insight, advanced knowledge and greater confidence.

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M.C.M. van Loosdrecht

Papers

Activated sludge models ASM1, ASM2, ASM2d and ASM3 (in Japaneese)

Activated sludge models ASM1, ASM2, ASM2d and ASM3

The sharon process: an innovative method for nitrogen removal from ammonium-rich waste water

Sewage Treatment with Anammox

Biological Wastewater Treatment: Principles, Modelling and Design