Publisher Summary This chapter highlights the physiology of autotrophic ammonia- and nitrite-oxidizing bacteria. Several aspects of the physiology of nitrifiers of relevance to their growth and activity in natural environments are considered. The chapter describes the basic features of the biochemistry of ammonia and nitrite oxidation and discusses the growth limiting factors and activity of these organisms. The influence of oxygen concentration, pH value, and inhibitors on their physiology is also described. Nitrification plays a central role in the nitrogen cycle of terrestrial and aquatic ecosystems, converting the most reduced form of nitrogen, NH3, to the most oxidized form, NO3. Nitrifying bacteria occupy niches in many ecosystems and compete successfully with faster and more efficiently growing organisms for oxygen, ammonia, and carbon dioxide. Nitrifiers are capable of reversing the nitrification process, carrying out denitrification and producing nitrite, ammonia, nitrous and nitric oxides, and gaseous nitrogen. Ammonia oxidizers can metabolize urea and can assimilate carbon from methane while nitrite oxidizers can grow anaerobically in the presence of organic compounds and nitrate.

Autotrophic nitrification in bacteria

Completely autotrophic nitrogen removal over nitrite in one single reactor

Oxygen minimum zones (OMZs) harbor unique microbial communities that rely on alternative electron acceptors for respiration. Conditions therein enable an almost complete nitrogen (N) cycle and substantial N-loss. N-loss in OMZs is attributable to anammox and heterotrophic denitrification, whereas nitrate reduction to nitrite along with dissimilatory nitrate reduction to ammonium are major remineralization pathways. Despite virtually anoxic conditions, nitrification also occurs in OMZs, converting remineralized ammonium to N-oxides. The concurrence of all these processes provides a direct channel from organic N to the ultimate N-loss, whereas most individual processes are likely controlled by organic matter. Many microorganisms inhabiting the OMZs are capable of multiple functions in the N- and other elemental cycles. Their versatile metabolic potentials versus actual activities present a challenge to ecophysiological and biogeochemical measurements. These challenges need to be tackled before we can realis...

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Microbial nitrogen cycling processes in oxygen minimum zones.

Many countries strive to reduce the emissions of nitrogen compounds (ammonia, nitrate, NOx) to the surface waters and the atmosphere. Since mainstream domestic wastewater treatment systems are usually already overloaded with ammonia, a dedicated nitrogen removal from concentrated secondary or industrial wastewaters is often more cost-effective than the disposal of such wastes to domestic wastewater treatment. The cost-effectiveness of separate treatment has increased dramatically in the past few years, since several processes for the biological removal of ammonia from concentrated waste streams have become available. Here, we review those processes that make use of new concepts in microbiology: partial nitrification, nitrifier denitrification and anaerobic ammonia oxidation (the anammox process). These processes target the removal of ammonia from gases, and ammonium-bicarbonate from concentrated wastewaters (i.e. sludge liquor and landfill leachate). The review addresses the microbiology, its consequences for their application, the current status regarding application, and the future developments.

New concepts of microbial treatment processes for the nitrogen removal in wastewater

Denitrification kinetics of high nitrate concentration water: pH effect on inhibition and nitrite accumulation

Competition in denitrification systems affecting reduction rate and accumulation of nitrite

Growth of nitrobacter in the absence of dissolved oxygen

A process incorporating sequencing batch reactors for organic removal and denitrification and a fixed-film device for nitrification was investigated in a bench-scale study. Emphasis was placed on the phenomena of sequestering of organic material and its later use as an electron donor for denitrification. Parameters varied to optimize system performance included the nature of the carbon source, the operating scheme during organic removal, and the nature of the nitrified feed stream to the denitrification stage. It was concluded that aeration for organic removal should be provided only until TOC and oxygen respiration sta bilize, providing a residual source of electron donor for later denitrifi cation. Further, a small amount of nitrite in the denitrification feed stream resulted in a robust population of organisms capable of reducing nitrite faster than nitrate, resulting in a 30% increase in the denitrification rate over systems fed only nitrate as an electron acceptor. Res. J. Water Pollut. Control Fed., 62, 259 (1990).

Denitrification in a batch wastewater treatment system using sequestered organic substances.

Bench- and pilot-scale experiments were conducted to investigate the feasibility of a three-stage sequencing batch reactor (SBR) process for carbon and nitrogen removal. Carbon removal was carried out in SBR operated under high loading conditions (Stage 1 ). Nitrification was accomplished in a fixed-film reactor (Stage 2), the effluent from which was returned to the SBR for denitrification ( Stage 3 ). Under both laboratory and field conditions, it was shown that sequestered substances remaining after completion of the Stage 1 process may increase the de nitrification rates by as much as an order of magnitude over true en dogenous rates. To ameliorate the development of a nitrite peak during denitrification, selection methods should be used that promote the growth of true denitrifiers. The overall nitrogen removal capacity of the system is limited to about 75%, not as a result of kinetic limitations but because of the necessity of retaining influent nitrogen in the settled sludge from the first stage. Res. J. Water Pollut. Control Fed., 62, 268 (1990). Biological nitrification and denitrification can be carried out in a variety of process configurations. Among these are proprie tary configurations such as the Bardenpho, Carrousel, Orbal, and Biodenitro processes1_5 as well as the sequencing batch re actor (SBR).6 Operation of these alternative systems requires very low loading rates and a long solids retention time (SRT). As a result, nitrogen removal via these processes is expensive in terms of both capital and operational costs,7 although some sav ings may be realized through reduced sludge management re sulting from lower yields at longer SRTs. Sequencing batch reactors have a distinct advantage over continuous flow processes in that reaction and aeration times are directly and separately controllable. Carbon removal, nitri fication, and denitrification can each be optimized individually, accounting for varying flow conditions and wastewater strengths through manipulation of the reaction periods. Further, with the advent of microprocessor technology, these processes can be controlled automatically at minimal expense. The SBR operates by separating in time, in a single tank, those processes that are separated spatially in a conventional continuous-flow process. A typical operation sequence consists of five steps: fill, react (with or without aeration), settle, decant, and idle. The sequence begins with the introduction of waste water to a partially filled reactor containing settled sludge from a previous cycle. The contents may remain unmixed during fill, a procedure that saves energy and aids in control of filamentous organisms.8-10 Aeration is provided for a length of time sufficient to produce an effluent of the desired quality. Aeration and mixing are then shut off, the microbial floes are allowed to settle under quiescent conditions, and the supernatant is finally drained from the reactor. During low-flow periods, a decanted reactor may undergo an idle period. Sequencing batch reactor systems have been successfully ap plied throughout the world for carbon removal, nitrification, and denitrification. As in continuous-flow systems, the problem with denitrification is an imbalance between availability and demand of electron donors. Often the denitrification rate as well as the quantity of oxidized nitrogen that can be reduced is limited. The purpose of this paper is to discuss the feasibility, advantages, and disadvantages of a method that has been proposed to increase the availability of electron donors without addition of supple mentary substances.

Operation of a three-stage SBR system for nitrogen removal from wastewater

Preface. List of Contributors. Key Note Address. 1 History and Mandate of Sustainability: From Local Forestry to Global Policy. 1.1 Sustainability: Key Word in the Today's Policy Discussion. 1.2 History and Definitions of "Sustainability". 1.2.1 Development of the Technical Terminus in Forestry. 1.2.2 Application in Environmental Politics. 1.2.3 The Definition of "Sustainability" - A Social Negotiation Process on Local and Global Levels? 1.3 Experiences from Forestry and Transfer into other Economic Fields - Possibilities and Limits. 1.3.1 Peculiarities of Forest Ecosystems and Forest Management. 1.3.2 Concept of Industrial Ecology. 1.3.3 Limits in Transferring the Forestry Model to other Economic Sectors. 1.3.4 Approximation to the Ideal "Sustainability". 1.4 Conclusion. Acknowledgement. References. 2 Sustainable Development: Exploring the Cross-Cultural Dimension. 2.1 Introduction. 2.2 Perspectives on Sustainable Development. 2.3 Prerequisites for Sustainable Development. 2.4 Sustainability: Essentials for a Realistic Cross-Cultural Concept. 2.5 Qualitative Growth as a Prerequisite for Sustainable Development. 2.6 Outlook. References. 3 Sustainable Development and Cultural Diversity. 3.1 Introduction. 3.2 The Vertical vs. Horizontal Dimension of Sustainability. 3.3 The Relevance of Cultural Diversity. 3.4 Globalization and Cultural Diversity. 3.5 Agricultural Sector. 3.6 Media Industry. 3.7 Tourism. 3.8 Conclusion. References. 4 Technological Progress in Different Cultures and Periods: Historical Evolution Projected into the Future. 4.1 Introduction. 4.2 Historical Perspective. 4.2.1 Why and Where Technological Progress? 4.2.2 Religious and Secular Approaches. 4.2.3 Perception of Nature as an Obstacle to Technical Progress. 4.2.4 Enlightenment: A Step towards Modern Times. 4.3 Modernity and the Sustainability Concept. 4.3.1 The Twentieth Century. 4.3.2 The Twenty-first Century. 4.4 In Search of a Coherent Evolution of Technology: Past and Future. 4.5 Conclusions. References. 5 Views of Sustainability: Elements of a Synthesis. 5.1 Introduction. 5.2 Definitions. 5.2.1 The Weak Version. 5.2.2 The Strong Version. 5.2.3 Alternative Views and Discussion. 5.3 Accounting for SD. 5.4 The Hartwick-Solow Rule. 5.5 Substitutability and the Role of Technical Progress. 5.6 Catastrophe Points. 5.7 Summary Classification of Economic Models. 5.8 Discount Rate. 5.9 Discussion. References. 6 A New Way of Thinking about Sustainability, Risk and Environmental Decision-Making. 6.1 Introduction. 6.2 Complicated Technology vs. Complex Technology. 6.3 Errors in Thinking and Attitudes. 6.4 The Current View of Sustainability and Risk Analysis. 6.5 A New View of Sustainability. 6.6 An Expanded View of Risk. 6.7 An Expanded Process of Environmental Decision Making. 6.8 Conclusions. References. 7 Humility and Establishing the Sustainable Environment. 7.1 Introduction. 7.2 Pristine Environments and Preservation. 7.3 Specieism. 7.4 Where Do We Go/How Do We Get There? 7.5 Conclusions. Acknowledgment. References. 8 Conflicts and Conflict-solving as Chances to Make the Concept of Sustainable Development Work. 8.1 Sustainability as a Conflict-generating Vision. 8.2 Approaches to Conflict Resolution. 8.3 The Integrative Concept of Sustainable Development as a Framework for Cultural Conflict Resolution. 8.3.1 The Integrative Concept - An Overview. 8.3.2 Conclusions Drawn for Cultural Conflict Management. 8.4 Research Perspectives. 8.5 Summary. References. 9 Sustainability through Science-Technology-Society Education. 9.1 Introduction. 9.2 What is Science-Technology-Society Education? 9.2.1 STS and Sustainability. 9.3 Sample Educational Topics Involving the Everglades. 9.3.1 A Sample Instructional Activity. 9.4 Issues. 9.5 Summary and Implications. References. 10 Sustainability and Consumption of Raw Materials in Germany. 10.1 Religion and Sustainability are in Great Demand. 10.1.1 Why do We Not Use the Knowledge of the Ancients? 10.1.2 The Present Economic Trends and Ecological Effects. 10.1.3 The Prices Do Not Say Ecological Truth. 10.1.4 Existence of the Possibility to Decouple Economic Growth from the Ecologic Destruction? 10.1.5 Sustainability as a Survival Strategy. 10.1.6 Worldwide Interlacing Will Make our Prosperity Safe. 10.2 Conclusions. References. 11 Sustainability, Culture and Regional Scales: Some Remarks from Human Geography. References. 12 Sustainable Development in Asia: Traditional Ideas and Irreversible Processes. 12.1 Introduction. 12.2 Population Growth as a Major Challenge to Sustainable Development. 12.3 Traditional Ideas of Sustainability and the Technocratic Ambitions of Modern Governments. 12.4 Sustainable Societies in Asia. 12.5 Conclusions. References. 13 Sustainability of Development and Valuation of Non-renewable Resources: An Analysis in the Context of Local Cultures. 13.1 Introduction. 13.2 Sustainability in the Context of Economics of Ecology. 13.3 Energy Options and Sustainable Development in the Developing World. 13.4 Cultural Norms and Concerns for Sustainability in Formulating Development Strategy by National and International Agencies. 13.5 Conclusions. References. 14 Sustainability in Latin American Countries: Challenge and Opportunities for Argentina. 14.1 Introduction. 14.2 Core Areas for Sustainable Development. 14.3 What are the Consequences? 14.4 Where Should We Go: Evolution and Tendency? 14.5 How Do We Get There: Driving Forces? 14.6 Eco-Efficiency Production. 14.7 Joining Efforts to Sustainable Development. 14.8 Some Cases from Argentina. 14.9 Conclusions. References. 15 On the Roles Engineers May Play in the Attempt to Meet Basic Demands of Man and Nature. 15.1 Millennium Development Goals. 15.2 Engineers and Sustainability. 15.3 Design of Technology in a Globalizing World. 15.3.1 The Cultural Dimension. 15.3.2 The Global Dimension. 15.3.3 Synthesis. 15.4 Urgent Questions to be Answered. 15.5 Conclusions. References. 16 Integrating Cultural Aspects in the Implementation of Large Water Projects. 16.1 General Conditions. 16.2 Agenda 21 and Integrated Water Resources Management as a Steering Model. 16.3 Parameters of Success Under the Aspect of "Implicit Culture". 16.4 Success Components According to the TTW-Model. 16.5 Appropriate Technology. 16.6 Management. 16.7 Personalities. 16.8 Idea of the Implementation of Cultural Strength as an "Explicit Cultural Aim". 16.9 Integral Planning. 16.10 Integral Redevelopment Models. 16.11 Conclusion: Systematic Implementation of Cultural Values as Project Assets. References. 17 Sustainability from an Entrepreneurial Point of View Seen from the Particular Standpoint of a Company Active in the Water Industry. 17.1 Introduction. 17.2 Role of Industry in Pursuing Sustainable Development. 17.3 Some Remarks about Water Industry. 17.4 Water Technology Considerations. References. 18 Synthesis. 18.1 Sustainability and Sustainable Development. 18.2 Postulates. References. Index.

Peter A. Wilderer

Papers

Competition in denitrification systems affecting reduction rate and accumulation of nitrite

Growth of nitrobacter in the absence of dissolved oxygen

Denitrification in a batch wastewater treatment system using sequestered organic substances.

Operation of a three-stage SBR system for nitrogen removal from wastewater

Global sustainability : the impact of local cultures : a new perspective for science and engineering, economics and politics