Waste Treatment

Microbial conversion of energy crops and organic wastes to biogas has become one of the most attractive technologies for energy production, resource recovery, and waste treatment. It creates a wide breadth of positive environmental impacts because it reduces emissions of greenhouse gases, improves the management of manure and organic wastes, and replaces mineral fertilizer. Biogas is used today mainly for electricity and heat production, but it can also be applied as a vehicle fuel or for the production of hydrogen which is necessary for fuel cells. Biogas production in the agricultural sector is a very fast growing market in many European countries. This paper presents the current situation in Germany which has the highest number of agricultural biogas plants in Europe.

The implementation of increasingly stringent standards for the dis- charge of wastes into the environment has necessitated the need for the develop- ment of alternative waste treatment processes. A review of research directed toward developing enzymatic treatment systems for solid, liquid and hazardous wastes is presented. A large number of enzymes from a variety of di†erent plants and microorganisms have been reported to play an important role in an array of waste treatment applications. Enzymes can act on speci-c recalcitrant pollutants to remove them by precipitation or transformation to other products. They also can change the characteristics of a given waste to render it more amenable to treatment or aid in converting waste material to value-added products. Before the full potential of enzymes may be realized, it is recommended that a number of issues be addressed in future research endeavors including the identi-cation and characterization of reaction by-products, the disposal of reaction products and reduction of the cost of enzymatic treatment.

Plasma waste treatment has over the past decade become a more prominent technology because of the increasing problems with waste disposal and because of the realization of opportunities to generate valuable co-products. Plasma vitrification of hazardous slags has been a commercial technology for several years, and volume reduction of hazardous wastes using plasma processes is increasingly being used. Plasma gasification of wastes with low negative values has attracted interest as a source of energy and spawned process developments for treatment of even municipal solid wastes. Numerous technologies and approaches exist for plasma treatment of wastes. This review summarizes the approaches that have been developed, presents some of the basic physical principles, provides details of some specific processes and considers the advantages and disadvantages of thermal plasmas in waste treatment applications.

List of Contributors. Foreword. Preface. Acknowledgements. 1.0. Introduction (Kevin R. Henke). Abstract. 1.1 Arsenic Origin, Chemistry, and Use. 1.2 Arsenic Environmental Impacts. 1.3 Arsenic Toxicity. 1.4 Arsenic Treatment and Remediation. 1.5 References. 2.0. Arsenic Chemistry (Kevin R. Henke and Aaron Hutchison). Abstract. 2.1 Introduction. 2.2 Atomic Structure and Isotopes of Arsenic. 2.3 Arsenic Valence State and Bonding. 2.4 Chemistry of Arsenic Solids. 2.5 Introduction to Arsenic Oxidation and Reduction. 2.6 Introduction to Arsenic Methylation and Demethylation. 2.7 Arsenic in water. 2.8 Chemistry of Gaseous Arsenic Emissions. 2.9 References. 3.0. Arsenic in Natural Environments (Kevin R. Henke). Abstract. 3.1 Introduction. 3.2 Nucleosynthesis: The Origin of Arsenic. 3.3 Arsenic in the Universe as a Whole. 3.4 Arsenic Chemistry of the Solar System. 3.5 Arsenic in the Bulk Earth, Crusts, and Interior. 3.6 Arsenic in Hydrothermal and Geothermal Fluids and their Deposits. 3.7 Oxidation of Arsenic-Bearing Sulfides in Geologic Materials and Mining Wastes. 3.8 Interactions between Arsenic and Natural Organic Matter (NOM). 3.9 Sorption and Coprecipitation of Arsenic with Iron and Other (Oxy)(hydr)oxides. 3.10 Arsenate (As(V)) Precipitation. 3.11 Reductive Dissolution of Iron and Manganese (Oxy)(hydr)oxides. 3.12 Arsenic and Sulfide at < 50oC. 3.13 Arsenic and its Chemistry in Mined Materials. 3.14 Marine Waters and Sediments. 3.15 Estuaries. 3.16 Rivers and Other Streams. 3.17 Lakes. 3.18 Wetlands. 3.19 Groundwater. 3.20 Glacial Ice and Related Sediments. 3.21 Arsenic in Air and Wind-blown Sediments. 3.22 Petroleum. 3.23 Soils. 3.24 Sedimentary Rocks. 3.25 Metamorphic Rocks. 3.26 References. 4.0. Toxicology and Epidemiology of Arsenic and its Compounds (Michael F. Hughes, David J. Thomas, and Elaina M. Kenyon). Abstract. 4.1 Introduction. 4.2 Physical and Chemical Properties of Arsenic. 4.3 Exposure to Arsenic. 4.4 Arsenic Disposition and Biotransformation in Mammals. 4.5 Systemic Clearance of Arsenic and Binding to Blood Components. 4.6 Tissue Distribution. 4.7 Placental Transfer and Distribution in the Fetus. 4.8 Arsenic Biotransformation. 4.9 Arsenic Excretion. 4.10 Effects of Arsenic Exposure. 4.11. Cardiovascular. 4.12. Endocrine. 4.13 Hepatic. 4.14 Neurological. 4.15 Skin. 4.16 Developmental. 4.17 Other Organ Systems. 4.18 Cancer. 4.19 Animal Models for Arsenic-induced Cancer. 4.20 Mechanism of Action. 4.21 Regulation of Arsenic. 4.22 References. 5.0. Arsenic in Human History and Modern Societies (Kevin R. Henke and David A. Atwood). Abstract. 5.1 Introduction. 5.2. Early Recognition and Uses of Arsenic by Humans. 5.3 Alchemy, Development of Methods to Recover Elemental Arsenic, and the Synthesis of Arsenic Compounds. 5.4 Applications with Arsenic. 5.5 Increasing Health, Safety, and Environmental Concerns. 5.6 Arsenic in Crime. 5.7 Poisoning Controversies: Napoleon Bonaparte. 5.8 Arsenic in Prospecting, Mining, and Markets. 5.9 Arsenic in Coal and Oil Shale Utilization and their Byproducts. 5.10 References. 6.0. Major Occurrences of Elevated Arsenic in Groundwater and Other Natural Waters (Abhijit Mukherjee, Alan E. Fryar, and Bethany M. O'Shea). Abstract. 6.1 Introduction. 6.2 Arsenic Speciation and Mobility in Natural Waters. 6.3 Immobilization of Arsenic in Hydrologic Systems. 6.4 Mobilization of Arsenic in Water. 6.5 Natural Occurrences of Elevated Arsenic around the World. 6.6 References. 7.0. Waste Treatment and Remediation Technologies for Arsenic (Kevin R. Henke). Abstract. 7.1 Introduction. 7.2 Treatment Technologies for Arsenic in Water. 7.3 Treatment Technologies for Arsenic in Solids. 7.4 Treatment Technologies for Arsenic in Gases. 7.5 References. Appendices. A: Common Physical and Chemical Constants and Conversions for Units of Measure. B: Glossary of Terms. B.1 Introduction. B.2 Glossary. C: Arsenic Thermodynamic Data. C.1 Introduction. C.2 Modeling Applications with Thermodynamic Data. C.3 Thermodynamic Data. D: Locations of Significant Arsenic Contamination. E: Regulation of Arsenic: A Brief Survey and Bibliography. E.1 Introduction. E.2 Regulation of Arsenic in Water. E.3 Regulation of Arsenic in Solid and Liquid Wastes. E.4 Sediment and Soil Guidelines and Standards for Arsenic. E.5 Regulation of Arsenic in Food and Drugs. E.6 Regulation of Arsenic in Air. E.7 Other References. Subject Index.

A literature review has been undertaken to investigate the performance of the different anaerobic process configurations and operational conditions used in poultry and livestock waste treatment. The results of the extensive literature review showed that a wide range of different reactor volumes varying from 100 mL to 95 m 3 were utilized in the investigation of anaerobic processing of poultry manure. Retention times studied were between 13.2 h and 91 days. Most of studies were carried out under mesophilic conditions maintained between 25 and 35°C. Chemical oxygen demand (COD) removals and organic loading rate (OLR) ranged from 32 to 78%, and from 1.1 to 2.9 kg COD m—3 day—1, respectively. Biogas yields were achieved between 180 mL g—1 COD added and 74 m3 day—1 for a wide range of different reactor configurations. Up-flow anaerobic sludge blanket (UASB) seems to be a suitable process for the treatment of poultry manure wastewater and the liquid fraction of hen manure, due to its ability to maintain a sufficient amount of active biomass. The literature review showed that various reactor configurations such as fixed-film reactor, attached-film bioreactor, anaerobic rotating biological reactor, batch reactors, downflow anaerobic filter, fixed dome plant, UASB, continuously stirred tank reactor (CSTR), up-flow anaerobic filter (UAF), temperature-phased anaerobic digestion (TPAD), anaerobic hybrid reactor (AHR), and two-stage anaerobic systems are well suited to anaerobic processing of cattle manure. At both mesophilic and thermophilic conditions, high COD removals (87—95%) were achieved for treatment of cattle manure wastewaters. The COD and volatile solids (VS) reductions obtained were 37.9 to 94% and 9.6 to 92%, respectively. During the studies, OLR and retention times ranged between 0.117 and 7.3 g VS L—1 day—1 and between 0.5 and 140 days, respectively. In anaerobic processing of cattle manure, methane yields between 48 mmol CH4 L— 1 and 4681.3 m3 CH4 month— 1 were found for the corresponding reactor volumes of 120 mL and 1300 m3, respectively. In anaerobic processing of swine manure, OLR ranged from 0.9 to 15.42 g VS L—1 day— 1 at mesophilic conditions (25—35°C). The reactor volumes varied between 125 mL and 380 L. Temperature and retention times ranged from 25 to 60°C, and 0.9 to 113 days, respectively. COD and VS reductions achieved were between 57 and 78% and between 34.5 and 61%, respectively. Moreover, methane yields were obtained between 22 and 360 mL CH4 g —1 VS added. The results showed that UASB, anaerobic baffled reactors, CSTR, and anaerobic sequencing batch reactor (ASBR) were successfully utilized in anaerobic processing of swine manure at both mesophilic and thermophilic conditions.

Fifty years have passed since the first application of separate sludge di gestion to waste treatment. During this period numerous reports have con tributed to the knowledge of anaerobic waste treatment systems. In recent years, primarily since 1960, more re search attention has been directed to ward the microbial population dy namics of anaerobic systems (1) (2) (3). This paper presents the results of a laboratory study into the biolog ical solids retention time aspects of anaerobic waste treatment.

Detailed and comprehensive accounts of waste generation and treatment form the quantitative basis of designing and assessing policy instruments for a circular economy (CE). We present a harmonized multiregional solid waste account, covering 48 world regions, 11 types of solid waste, and 12 waste treatment processes for the year 2007. The account is part of the physical layer of EXIOBASE v2, a multiregional supply and use table. EXIOBASE v2 was used to build a waste‐input‐output model of the world economy to quantify the solid waste footprint of national consumption. The global amount of recorded solid waste generated in 2007 was approximately 3.2 Gt (gigatonnes 1 ), of which 1 Gt was recycled or reused, 0.7 Gt was incinerated, gasified, composted, or used as aggregates, and 1.5 Gt was landfilled. Patterns of waste generation differ across countries, but a significant potential for closing material cycles exists in both high‐ and low‐income countries. The European Union (EU), for example, needs to increase recycling by approximately 100 megatonnes per year (Mt/yr) and reduce landfilling by approximately 35 Mt/yr by 2030 to meet the targets set by the Action Plan for the Circular Economy. Solid waste footprints are strongly coupled with affluence, with income elasticities of around 1.3 for recycled waste, 2.2 for recovery waste, and 1.5 for landfilled waste, respectively. The EXIOBASE v2 solid waste account is based on statistics of recorded waste flows and therefore likely to underestimate actual waste flows.

Part 1 Fundamentals of radioactive materials separations processes: chemistry, engineering and safeguards: Chemistry of radioactive materials in the nuclear fuel cycle Physical and chemical properties of actinides in nuclear fuel reprocessing Chemical engineering for advanced aqueous radioactive material separations Spectroscopic on-line monitoring for process control and safeguarding of radiochemical streams in nuclear fuel reprocessing Safeguards technology for radioactive materials processing and nuclear fuel reprocessing facilities. Part 2 Separation and extraction processes for nuclear fuel reprocessing and radioactive waste treatment: Standard and advanced separation: PUREX processes for nuclear fuel reprocessing Alternative separation and extraction: UREX+ processes for actinide and targeted fission product recovery Advanced reprocessing for fission product separation and extraction Combined processes for high level radioactive waste separations: UNEX and other extraction processes. Part 3 Emerging and innovative techniques in nuclear fuel reprocessing and radioactive waste treatment: Nuclear engineering for pyrochemical treatment of spent nuclear fuels Development of highly selective compounds and processes for solvent extraction of long-lived radionuclides from spent nuclear fuels Developments in the partitioning and transmutation of radioactive waste Solid-phase extraction technology for actinide and lanthanide separations in nuclear fuel reprocessing Supercritical fluid and ionic liquid extraction techniques for nuclear fuel reprocessing and radioactive waste treatment Development of biological treatment processes for the separation and recovery of radioactive wastes.

Efficient nuclear waste treatment and environmental management are important hurdles that need to be overcome if nuclear energy is to become more widely used. Herein, we demonstrate the first case of using two-dimensional (2D) multilayered V2CTx nanosheets prepared by HF etching of V2AlC to remove actinides from aqueous solutions. The V2CTx material is found to be a highly efficient uranium (U(VI)) sorbent, evidenced by a high uptake capacity of 174 mg g(-1), fast sorption kinetics, and desirable selectivity. Fitting of the sorption isotherm indicated that the sorption followed a heterogeneous adsorption model, most probably due to the presence of heterogeneous adsorption sites. Density functional theory calculations, in combination with X-ray absorption fine structure characterizations, suggest that the uranyl ions prefer to coordinate with hydroxyl groups bonded to the V-sites of the nanosheets via forming bidentate inner-sphere complexes.

Cost estimation is a basic requirement for planning municipal solid waste management systems. The variety of organizational, financial and management schemes and the continuously developing technological advancements render the economic analysis a complex task, made more complex by the scarcity of real cost data. The objectives of this paper were: (1) to explore the problems arising in getting cost estimates from scattered and limited published data; (2) to suggest a procedure for generating cost functions relating initial set-up cost and operating cost with facility size; and (3) to present such cost functions, relevant to European states, for selected types of solid waste treatment and disposal facilities. Regarding the problems of available scarce data, one needs to deal with cost figures which correspond to facilities with variations in size, technology, year of construction, working conditions, level of technological automation, environmental impacts, social acceptance, capacity utilization rate, composition of inflowing waste, waste management policies, degree of compliance with quality standards, etc. The paper addresses this issue and discusses the proper use of statistical analyses in such cases of fragmented data; moreover, it points out some usual misuses of statistics by analysts and the danger of getting erroneous results. The suggested process for generating cost functions acceptable to the decision-makers is pivoted around the question of acceptable approximation level. Finally, approximate cost curves are suggested for waste-to-energy facilities, landfilling facilities, anaerobic digestion facilities and composting facilities.