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Showing 1401 - 1205 of 1205 Journals sorted alphabetically
Transportation Research Record : Journal of the Transportation Research Board     Full-text available via subscription   (Followers: 32)
Transportmetrica A : Transport Science     Hybrid Journal   (Followers: 8)
Trends in Applied Sciences Research     Open Access   (Followers: 1)
Tribology in Industry     Open Access   (Followers: 4)
Tribology International     Hybrid Journal   (Followers: 46)
Tribology Letters     Hybrid Journal   (Followers: 7)
Tribology Transactions     Hybrid Journal   (Followers: 35)
Trilogía     Open Access  
Turkish Journal of Engineering     Open Access  
Turkish Journal of Engineering and Environmental Sciences     Open Access   (Followers: 1)
Türkiye Arazi Yönetimi Dergisi     Open Access  
Türkiye Coğrafi Bilgi Sistemleri Dergisi     Open Access  
Türkiye Fotogrametri Dergisi     Open Access  
Türkiye İnsansız Hava Araçları Dergisi     Open Access  
U.Porto Journal of Engineering     Open Access  
UKH Journal of Science and Engineering     Open Access  
Ultramicroscopy     Hybrid Journal   (Followers: 4)
Uludağ University Journal of The Faculty of Engineering     Open Access  
Uluslararası Mühendislik ve Teknoloji Araştırmaları Dergisi / International Journal of Engineering and Technology Research     Open Access  
Universal Journal of Applied Science     Open Access   (Followers: 2)
Universal Journal of Engineering Science     Open Access   (Followers: 2)
Universidad, Ciencia y Tecnología     Open Access   (Followers: 1)
Usak University Journal of Engineering Sciences     Open Access  
Utilities Policy     Hybrid Journal   (Followers: 2)
Vacuum     Hybrid Journal   (Followers: 12)
Vestnik of Don State Technical University     Open Access  
Vibration     Open Access   (Followers: 16)
Virtual and Physical Prototyping     Hybrid Journal   (Followers: 4)
Visualization in Engineering     Open Access   (Followers: 1)
Walailak Journal of Science and Technology     Open Access  
Waste and Biomass Valorization     Hybrid Journal   (Followers: 3)
Waste Management Series     Full-text available via subscription   (Followers: 1)
Waves in Random and Complex Media     Hybrid Journal  
Waves, Wavelets and Fractals - Advanced Analysis     Open Access  
Wear     Hybrid Journal   (Followers: 27)
Welding in the World     Hybrid Journal   (Followers: 7)
West African Journal of Industrial and Academic Research     Open Access   (Followers: 2)
World Electric Vehicle Journal     Open Access  
World Journal of Engineering and Technology     Open Access  
World Journal of Environmental Engineering     Open Access   (Followers: 3)
World Pumps     Full-text available via subscription   (Followers: 2)
World Science and Technology     Full-text available via subscription  
Yugra State University Bulletin     Open Access   (Followers: 1)
ZDM     Hybrid Journal   (Followers: 1)
Zede Journal     Open Access   (Followers: 1)
Zeitschrift für Arbeitswissenschaft     Hybrid Journal  
Zeitschrift fur Energiewirtschaft     Hybrid Journal  
Вісник Приазовського Державного Технічного Університету. Серія: Технічні науки     Open Access  

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Waste Management Series
Number of Followers: 1  
 
  Full-text available via subscription Subscription journal
ISSN (Print) 1478-7482
Published by Elsevier Homepage  [3207 journals]
  • Series Page
    • Abstract: Publication date: 2006
      Source:Waste Management Series, Volume 7


      PubDate: 2014-09-19T05:20:59Z
       
  • Chapter 1 Introduction
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter discusses the concept of integrated waste management. It is necessary to plan and implement an overall waste management program such that its various elements are compatible with one another. The compatibility of the elements of the program has led to the widespread use of the term, “integrated waste management.” In solid waste management nomenclature, the term “integrated” would be reserved for systems, schemes, operations, or elements in which the constituent units can be designed or arranged such that one meshes with another to achieve a common overall objective. The first medium- and large-scale processes were designed to treat the entire municipal solid waste (MSW) stream. It is possible that the designs of the facilities were appropriate at that time because the major constituents of the municipal solid waste were of biological origin. The integration of various processes is a necessity to meet high levels of waste diversion and reduce the reliance on land disposal. The collection and treatment of the organic fraction of MSW can help meet regulatory and other requirements associated with the reduction of the quantities of waste reaching the landfill. Composting is a relatively simple and cost-effective method of treating organic wastes.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 2 History of composting
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter examines the history of urban waste generation and its management. The early composting methods were being refined in India, China, Malaysia, and in other countries. Mechanization was developed for the use of composting as a method for the treatment and sanitary disposal of municipal solid waste. These efforts resulted in several mechanical innovations. Some of the main objectives of these processes were to improve the aesthetics of the composting process by enclosing the material in some type of structure and to reduce the amount of time required to stabilize the composting material. Several experimental studies were conducted on composting in a silo-type digester using mechanical mixing. The result of this work demonstrated that a substantial amount of attention had been paid to the development of more efficient mechanical stirring and to the solution of mechanical problems associated with digester operations. Silo digesters had been used primarily in relatively small installations for segregated waste having a high concentration of organic matter. The processing units were highly mechanized to provide continuous aeration and were designed to try to reach thermophilic temperatures to achieve rapid degradation.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 3 Microbiology of the composting process
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter discusses the microbiology of the composting process. The biological cycling of nutrients is indispensable for life and is mediated through microorganisms. Biotransformation is a biological modification that alters the chemical structure of a substance. The decay of materials during composting follows the common biochemical pathways of any other degradation process. Generally, plant materials make up the highest amounts, while animal tissues or microbial components are only minor fractions of any mixture, but usually are the most nutrient-rich fractions. The degradation of organic compounds under natural conditions usually occurs in soils and sediments, on the soil surface, or in water bodies. In most cases, the decomposing substrates have physical contact with the degraded material or with an external matrix. Continuous composting processes may be regarded as a sequence of continuous cultures, each of them with their own physical, chemical, and biological properties and feedback effects. All of the microbial transformations of nitrogen occurring in nature also take place during composting, even if with different significance.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 4 Factors that affect the process
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter examines the factors that affect the composting process. In composting, the substrate is the waste to be composted and, similar to any other biological process, the chemical and physical characteristics of the substrate are critical in the viability of the process. The complexity and nature of the molecular structure of the substrate are particularly important because these characteristics define the assimilability of nutrients by various microorganisms. Composting is a bio-oxidative microbial degradation process of mixed organic matter. This exothermic process produces a relatively large quantity of energy. High pH values in the starting material in association with high temperatures can cause a loss of nitrogen through the volatilization of ammonia. Water is essential for all microbial activity and should be present in appropriate amounts throughout the composting cycle. Optimal moisture content in the starting material varies and essentially depends on the physical state and size of the particles and on the composting system used.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 5 Systems used in composting
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter discusses the steps associated with compost and product preparation. One of the key purposes of equipment in composting is to provide the microorganisms responsible for the degradation with an optimum environment within the constraints brought about by financial feasibility. General experience in composting has shown that availability of oxygen is the environmental factor of most concern. Physical movement of particles, also known as agitation, is accomplished in two ways: tumbling and stirring. During the tumbling process, the particles are lifted and then allowed to drop or fall. The gaseous envelope around the particle is renewed during the mechanical process of agitation. There are some general guidelines that can be applied to maximize the potential for a composting system to be efficient, produce a product of suitable quality, and be cost effective. The first and very important guideline is that a composting system does not have to be technically complicated to be successful. The second guideline requires that the system to be used should be readily adaptable to the labor and economic conditions of the community in which it is to be used. The general classification of composting systems is also presented in the chapter.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 6 Design of composting plants
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter describes the different aspects of the designs of composting plants. The aesthetics of a composting plant must become an important component of the design to achieve sustainable development and to avoid repeating costly mistakes. A proper architectural approach to the design of a composting plant makes a substantial contribution to its integration with its surroundings and better acceptance by the public. The design and implementation of a composting plant involves a number of contributions from a variety of disciplines, such as architecture, civil works, and those involved in the technical facilities. A composting plant for size reduction and the stabilization of mixed organic waste should be located as close to the disposal site as possible. This typically is an interim solution because the landfill will eventually be closed. The closure plan for the landfill should aim at making the site inconspicuous in the landscape. The configuration of all the units of a composting plant has to be not only required by the necessity of the machinery, but also by the need of existing urban patterns and an aesthetical solution for the building.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 7 Quality and agronomic use of compost
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter describes the quality and agronomic use of compost. The main positive aspect of compost use in agriculture is probably related to the sustainability of this practice. The application of compost to soil is of considerable interest as a means of maintaining a suitable soil structure, as well as a means of adding organic material to soil whose organic matter content has been reduced by the practice of intensive agriculture. The concentration of nitrogen in compost is probably the most interesting from either an environmental or an agronomic point of view and this is the reason for using N content as the basis for calculating the application rates of compost. Soil water and thermal regime influence the redox processes of heavy metals and the more general decomposition processes of compost organic matter. The depth of soil tillage also is important because it determines the nature of the contact and the reactions between metals and soil constituents. The variety and complexity of physico-chemical and biological components in compost and in a soil system affect the possibility of studying the effects of the addition of organic materials into the soil.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 8 Bioremediation
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter describes key features of the application of biological processing to the treatment of toxic and hazardous organic wastes and discusses the use of such processing to remediate sites contaminated with hazardous wastes. The biological treatment of waste necessarily means that the waste is susceptible to successful decomposition by microorganisms and microorganisms can utilize the waste as a source of carbon and energy. Enrichment is the technique of establishing conditions that favor the proliferation of microbes capable of using the nutrient elements present in the molecules of the substrate. In the case of composting toxic organics, the sole source of nutrient elements would be the molecules of the toxic compounds. The types and intensities of odor emanating from a composting mass reveal shortcomings in operational and environmental factors, as well as deficiencies in the amount of degradation, stability, or the quality of the end product. Composting has been demonstrated to be moderately effective in remediating soil contaminated with polychlorinated biphenyls.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 9 Pathogenic agents
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter describes the pathogens of humans, animals, and plants that may be present in organic wastes. The recycling of biological wastes by aerobic or anaerobic biotechnological treatment is necessary to protect the environment and to save natural resources. The recycling process may be conducted either in large-scale plants operated mostly in urban industrial areas, or in small plants operated primarily in the rural environment to improve the farmer's income. A relatively large number of pathogens are found in solid and liquid organic wastes and the most prevalent are bacteria, viruses, fungi, and parasites. Fungi present in wastes and materials used for composting are mainly of interest from the point of view of occupational health and phytohygiene. The presence of parasites or their infective stages in wastes or residues of plant, animal, or human origin depends on the nature of the wastes and the level of pretreatment. Parasites are of veterinary and medical importance if the raw materials used for composting are generated in wastewater treatment facilities or in slaughterhouses. Plant pathogenic parasites must also be considered, even if some of them are highly specialized on certain plants, which limit their epidemiological importance. Cyst-forming nematodes are the most relevant because these cysts may survive in the soil for several years.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 10 Suppression of soil-borne phytopathogens by compost
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter examines the suppression of soil-borne phytophathogens by compost. Compost is used in agriculture and horticulture as a fertilizer or to improve the physical structure of soil, including potting soil mixtures. Compost-amended soil has been found to show enhanced suppression of plant diseases caused by soil-borne nematodes, fungi and bacteria, in various cropping systems. The maturity and stability of compost are important for the degree of disease suppressiveness of soil that can be achieved. In stable compost, easily degradable carbon sources have been used by the microflora present, leading to a stable microbiological system. The microbial succession during the composting process can be separated into different phases, as guided by the temperature regime. The spiking of compost with disease-suppressive microorganisms is a method that may enhance the disease-suppressive properties of compost. During the thermophilic phase of the composting process, many organisms are killed. The correlation between compost-amended soil microflora and disease suppression is also discussedin the chapter.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 11 Odor emissions from composting plants
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter discusses the odor emissions from composting plants. Odor emissions are one of the main problems in the planning of a composting facility. The main sources of odors are (1) the raw material, (2) the metabolic products that arise during aerobic degradation, and (3) some of the metabolic products during anaerobic degradation. Another factor governing odor formation is the method of the operation of the composting plant. The chapter presents a study in which the analysis of the total carbon content of the sample air by means of an FID was carried out simultaneously with most of the measures for odorant concentrations. The odorant concentration of the gas sample to be measured is determined by dilution with neutral air down to the odor threshold. Unavoidable odors are those arising from the anaerobic and aerobic transition products and process-related metabolic products, which are generated during decomposition by turning or the aeration of windrows. It has been found that olfactometric measurements allow statements about odorant concentrations at the point of emissions.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 12 Marketing of composts
    • Abstract: 2007
      Publication year: 2007
      Source:Waste Management Series, Volume 8

      This chapter presents the evaluation of the market potential of compost products. The size of a particular market for compost depends, to a large extent, on the quality of the compost and on the types of uses for the material. Composts from different types of substrates have different characteristics and consequently have different potential markets. The agricultural industry is the largest potential market for compost, particularly compost produced from the organic fraction of municipal solid waste (MSW). Public agencies have the potential to use both high- and low-quality composts. High-quality compost can be used in areas where humans and/or animals may come in direct contact with the materials. Lower quality compost would be suitable for land reclamation and filling. The residential sector also represents a sizeable market for soil amendments. The results of marketing surveys show that a large number of people expressed a preference to use compost from yard waste than from the organic fraction of MSW or from biosolids.

      PubDate: 2012-12-15T09:51:58Z
       
  • Foreword
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7



      PubDate: 2012-12-15T09:51:58Z
       
  • Acknowledgements
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7



      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 1 Introduction
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses complete waste management systems. Recycling, resource recovery, waste management, and environmental protection have been among the major concerns in almost all extraction and process industries. A complete waste management system today must comprise waste reduction, reuse, recycling, and resource recovery, commonly referred to as 4 Rs, in addition to disposal methods, such as landfill and incineration. Reduction refers to the actions that lessen the quantity of waste generated and eventually needs to be managed. It is also called “waste minimization” and requires adopting existing technologies in such a way as to maximize the efficiency of production, collect the byproducts and waste generated, and explore their use for beneficial purpose. Integrated waste management source reduction and reuse receive priority; however, recycling is emphasized because it potentially prevents useful material from being combusted or land filled, thus, reducing the cost of waste disposal and reducing landfills and tailing ponds. The processing of such metallurgical wastes and the recovery of valuable components and in some cases converting them into useful compounds will not only help to reduce pressure on ponds and landfills, but also it will, at least in part, offset the cost of environmental protection.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 2 Waste Characterization
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the process of waste characterization in metallurgical industry. It is necessary to characterize the waste, both in terms of chemical and mineralogical composition. Chemical composition is determined by digesting the material in appropriate acids, usually hydrochloric acid and when required nitric acid, and analyzing the solution by atomic absorption spectroscopy. In the majority of techniques, a surface is analyzed by measuring the emitted radiation after bombardment by an electromagnetic particle or wave. To perform meaningful surface analysis, it is necessary to know the physical properties of the excitation beam together with the physics of interaction with the sample and the character of the emitted particles. The identification of minerals in a sample is facilitated by image analysis. If a mineral displays a unique grey level in the black and white image, or a distinct color in the color image, its image is segmented from the image of the field of view. On-line identification of materials, as they are crushed and separated in different size ranges, is of great use to achieve higher recovery of recyclable material because it enables the selection of separation process and the optimization of process parameters.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 3 Physical and physico-chemical processes
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the importance of physical and physico-chemical processes in metallurgical industry. Physical processes, which usually do not require chemical agents, are often sought after for materials separation. They are based on exploiting the differences in specific physical properties, such as specific gravity, magnetic properties, and electrical conductivity. Physico-chemical processes are based on the surface chemical characteristics of the components to be separated. The success of the physical and physico-chemical methods is determined by variations in such properties among individual components to be separated and recovered. A principal requirement for the success of any physical separation process is that the individual components to be separated should be satisfactorily liberated from each other and the two should not be bound together in a chunk. In precipitate flotation, an ionic species is concentrated from an aqueous solution by forming a precipitate, which is then removed by flotation. An important feature of precipitate flotation is the low value of collector to colligend ratio because each macroscopic particle contains a large number of colligend ions, but only requires a monolayer of collector on the surface for good flotation.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 4 Hydrometallurgical processes
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter examines the different aspects of the hydrometallurgical processes. The recovery of metal values and other potentially useful products from metallurgical wastes often requires chemical treatment. Dissolved metal ions in solution can be precipitated as insoluble or sparingly soluble compounds. Most of the common heavy metal ions, such as Fe, Cu, Zn, and Ni, in metallurgical effluents can be precipitated as hydroxides, sulfides, carbonates or phosphate. The recovery of metal ions from solution by ion exchange process has been used for many years in process industry. Strong acid resins are produced by introducing sulfonic acid groups into the three-dimensional hydrocarbon backbone structure of a polymeric resin. Weak acid resins are based on a carboxylic acid grouping achieved by the synthesis of a polymer. Strong base resins are made by introducing a quaternary ammonium grouping onto the hydrocarbon backbone of the resin. When the resin is completely ionized as with strong acid and strong base resins, the effective capacity and maximum capacity are the same because the number of exchangeable groups equals the number of ionogenic groups.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 5 Biotechnological processes
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the sources of biomass and possible mechanisms of metal uptake, along with their potential in metal recovery from metallurgical effluents. Certain natural materials of biological origin can retain large quantities of metal ions by one of the different possible mechanisms, including sorption and complexation. The biological material of such properties is called “biomass” and the phenomenon is called “biosorption.” It has been exploited for the separation and recovery of metals from effluents and for toxicity removal. An economical source of biomass for the production of biosorbents is spent biomass from a fermentation process for the manufacturing of biochemical products, such as antibiotics, enzymes, organic acids, and possibly vitamins. An abundant source of mixed microbial biomass is the activated sludge wastewater treatment process. The biomass from the fermentation process may have to be passed through a sieve to remove particulate material. This material can be present as an insoluble component of the fermentation medium and adds nothing to the biosorption agent. Biological treatment systems where live microbial sludge or biofilms serve the function of metal sorbers have been used in many places for the collection and removal of heavy metals from industrial metal-containing effluents.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 6 Pyrometallurgical processing
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter examines the different aspects of pyrometallurgical processing. Pyrometallurgical processing involves high temperature reactions, roasting, smelting, and converting. A variety of high temperature furnaces are used in metallurgical industry. Primary smelting operations have a high capacity and a tolerance for fine powdered materials containing minor impurities and for mixed metallic scrap unsuitable for direct recycling to the foundry industry. Sweating furnace is any furnace operated at a temperature where a portion of the charge liquefies and can be drained off. Sweating most commonly applies in aluminum recycling where it is desired to separate aluminum from iron or brass. The most important benefit of flash smelting is the effective containment of sulfur dioxide produced in sulfide roasting. This has resulted in waste minimization by marked reduction in sulfur dioxide emission and consequent environmental benefit. Because it utilizes the exothermic properties of sulfide minerals, the process requires very little additional fuel.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 7 Metal recycling
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the principal processes of recycling metals from metallurgical scrap. Metallurgical scrap is generated in industries using metals as auto parts, machinery, and other engineering materials. A review of the principal techniques and processes employed for recovery and recycling in iron and steel industry is presented in the chapter. The reduction of the size of large scrap material to enable consolidation, shipment, and subsequent feeding into furnaces is done using suitable equipments, such as shears, flatteners, and torch-cutting and turning crushers. The sweat furnace is used by many metal scrap recyclers for the purpose of separating aluminum, zinc, and/or lead from iron in composite parts. It can also be used to remove contaminants, such as dirt, rubber, plastics and other combustibles, from aluminum, zinc and lead-beating scrap. In addition, the furnace can be used to compact loose and bulky nonferrous scrap for transportation to a secondary smelter. Tin affects the impact properties of steel and is apparent only in the presence of copper. The electrolytic detinning process consists of leaching in a hot alkaline solution. Metallic tine dissolves quickly, while the tine that has alloyed with the iron takes longer. The dissolution reaction is accelerated through simultaneous electrolysis.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 8 Metallurgical slags, dust and fumes
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter examines the formation and properties of metallurgical slags, dust, and fumes. Slags, dust, and fumes are common products in almost all extractive metallurgical operations. Dust and fumes may contain toxic metals in fine particle size and as such are a potential environmental and health hazard. They are a potential secondary source of many metals and also can be converted into useful by-products of practical value. In extractive metallurgical operations, a slag phase is generated, formed mainly from the addition of the mixtures of oxides and fluxes and is also composed of reaction products like those resulting from the oxidation of charge materials and the dissolution of refractories. The physical structure and the gradation of granulated slag depend on the chemical composition of the slag, its temperature at the time of water quenching, and the method of production. Chemical composition of the slag varies with the stage in the process in which it is generated. Several treatment procedures have also been suggested in the chapter to enhance to properties of steelmaking slags for incorporation into asphalt.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 9 By-product processing and utilization
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the by-product processing and utilization in metallurgical processes. Many of the secondary or waste products contain valuable material, which can be recovered through new technologies, or they can be directly used for specific industrial, construction, or agricultural purposes, sometimes after appropriate treatment. The conversion of such materials to valuable, marketable products could lead to the development of secondary or spin off industries and they can be useful by-products of the original process. The use of iron blast furnace slag as a cement supplement is one of the big successes in the field of by-product recycling industry. Slag utilization in construction is an overall process including several stages from slag production to end uses. Successful utilization is generally based on several stages or links. The properties of slag is advantageous in applications where chemically inert material with the characteristics of cement is desired. Potential use of steel industry slag to construct landfill covers has also been described in the chapter.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 10 Resource recovery from process wastes
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the resource recovery from process wastes metallurgical industry. The extraction of valuable metals or minerals from ores, the processing of concentrates resulting from the beneficiation of these ores by pyrometallurgical and /or hydrometallurgical means, and the commercial use of the extracted metals or minerals results in a wide variety of by-products. Some of these by-products contain residual metals or minerals of commercial value and may be reprocessed for the recovery of these additional and often different metals or minerals. Acid rock drainage is often treated by precipitating all metals as hydroxides by mixing lime to a pH 9–10. The discharge water is practically free of dissolved heavy metals, such as Fe, Cu, and Zn. The last two are considered to be toxic and their removal is essential before the reclaimed water is discharged or recycled. This conventional method results in a bulky precipitate of metal hydroxides, but does not leave room to recover metal values, in particular, copper and zinc. Gold is conventionally recovered from the associated minerals by alkaline cyanide leaching. The mill railings may be pretreated by sulfuric acid. The acid completely decomposes calcite, but has no discernible effect on goethite, jarosite, or quartz.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 11 Recycling of water and reagents
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the recycling of water and reagents in the metallurgical industry. Water has many vital functions in almost every mineral and metal processing operation. It is used as a carrier for fine solids, provides a column in which separation processes take place, is used in dust collection and cleaning systems, is employed in smelter refractory cooling systems, and is a reagent in hydrometallurgical operations. The water inevitably picks up fine solid particles, soluble slats, and organic materials in the course of this use necessitating purification treatment to make it suitable for recycling or before discharge to water courses is permitted. The recycling of water from various solid–liquid separations on the concentrate and tailing streams is called internal reuse. The reclamation of water from tailing pond areas, usually more distant from the concentrator, is called “external reuse.” Active carbon is an effective adsorbent for both inorganic and organic compounds. Industrial active carbon is prepared by degasifying charcoal. Metal binding capacities of various microorganisms are potentially useful to remove hazardous metals from wastewater and facilitate its reuse. Many biomasses, such as peat moss, often exist in small sponge floes, which generally necessitate suitable solid–liquid separation downstream of a reaction tank.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 12 Emerging new technologies
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 7

      This chapter discusses the development of technologies for resource recovery from mineral and metallurgical wastes. Many of these techniques, based on physico-chemical principles, originated and were applied in other separation processes, such as the separation of organic molecules and biochemicals of importance in pharmaceutical industry. Magnetic carriers are magnetic materials designed to bind selectively on a nonmagnetic material to separate using magnetic separation techniques. Generally, a probing molecule or reactive functional group on magnetic carriers has a specific affinity to targeted biological cells or metal ions. The interaction between fabricated magnetic particles and target molecules can be described by a key and lock relationship. The most widely used technique for covalently placing reactive organic groups on inorganic species is through the reaction of inorganic surface with silane coupling agents with dual functionalities, inorganic group at one end and organic group at the other. Magnetic resin beads do not settle to a close-packed bed, but form loose floes containing large volumes of void water. This property makes it possible for the resins to be pumped without attrition, and also enables suspended solids in the feed stream to pass through the resin bed without blinding it.

      PubDate: 2012-12-15T09:51:58Z
       
  • In remembrance to Stephen Tiong-Lee Tay
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6



      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 1 Mechanisms and models for anaerobic granulation
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter reviews the existing mechanisms and models for anaerobic granulation in upflow anaerobic sludge blanket (UASB) systems and builds up a general model for anaerobic granulation. The inert nuclei model for anaerobic granulation was initially proposed by Lettinga. This model suggests that the presence of nuclei or microsize biocarrier for bacterial attachment is a first step toward anaerobic granulation. The selection pressure model suggests that microbial aggregation in UASB reactor appears to be a protective microbial response against high selection pressures. In UASB reactors, selection pressure is created by upflow liquid flow pattern. It has been reported that under very weak hydraulic selection pressure operating conditions, no anaerobic granulation is observed. The results have shown that flocculant anaerobic sludge could be converted into a relatively active granular sludge by enhancing agglomeration through short hydraulic stress of less than 8 h. The attrition model proposed that granules originate from fines formed by attrition and from the colonization of suspended solids from the influent. The secondary minimum adhesion model is based on the DLVO theory for colloidal particles, which proposes that reversible adhesion takes place in the secondary minimum of the DLVO free energy curve.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 2 Factors affecting anaerobic granulation
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter analyzes the factors affecting anaerobic granulation. Anaerobic decomposition of organics is accomplished through a series of biochemical reactions, which is very dependent on temperature. Most take place at mesophilic condition. As a core microbial component of anaerobic granules, methanogenic bacteria grow slowly in wastewater and their generation times range from 3 days at 35°C to as high as 50 days at 10°C. There is an optimum range of temperature for successful functioning of anaerobic system. Most upflow anaerobic sludge blanket (UASB) reactors are operated at mesophilic range, though some can be operated at a temperature as high as 70°C. Anaerobic granular sludge systems are most suitably operated for the treatment of municipal wastewater at low and moderate temperatures. The relatively low pH conditions facilitate the maintenance of anaerobic granular structure and can be satisfactorily explained by the proton translocation-dehydration theory. The characteristics of feed are also considered a key factor influencing the formation, composition, and structure of anaerobic granules. The complexity of substrate may exert a selection pressure on microbial diversity in anaerobic granules, which influences the formation and microstructure of granules.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 3 Applications of anaerobic granulation
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter presents an overview of the applications of anaerobic granulation. Anaerobic treatment process has been successfully applied in various types of industrial wastewaters. It ranges from food wastewaters to nonfood wastewater, such as chemical plants. Food, breweries, and beverages industries have the largest share of anaerobic treatment plants built to treat their wastewaters. The data also affirms that anaerobic treatment is an established technology for a wide variety of industrial applications. The upflow anaerobic sludge blanket (UASB) reactors have been applied to a wide range of industrial wastewater, including those containing toxic or inhibitory compounds. Anaerobic treatment processes are suitable in tropical conditions because anaerobic treatment functions well in temperatures exceeding 20°C. They are characterized by low sludge production and low energy needs. Anaerobic sludge bed reactor systems can be started within a few days with granular seed sludges and they may be applied across a wide range of conditions and strengths of wastewater. Expanded granular sludge bed reactor (EGSB) systems are particularly suited to low temperatures and low strengths and for the treatment of recalcitrant or toxic substrates.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 4 Mechanisms of aerobic granulation
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter focuses on the mechanisms of aerobic granulation. Aerobic granulation is a process of microbial self-immobilization without the support of a carrier. Similar to the formation of biofilms and anaerobic granules, aerobic granulation should be a multiple-step process in which a number of physico-chemical and biological factors should be involved. Many factors have been known to affect the formation of aerobic granules in sequencing batch reactor (SBR). Compared with continuous microbial culture, the main feature of SBR is its cycle operation—that is, each cycle consists of filling, aeration, settling, and discharging. In SBR, the settling time is likely to exert a selection pressure on the sludge particles. Only particles that can settle down within a given settling time would be retained in the reactor, otherwise they would be washed out of the system. Selection pressure in terms of upflow velocity has been recognized as a driving force toward successful anaerobic granulation in upflow anaerobic sludge blanket (UASB) reactors. Similarly, in aerobic granulation, a selection pressure should be created to promote the formation of aerobic granules in SBR.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 5 Factors affecting aerobic granulation
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter discusses the factors that affect aerobic granulation. Aerobic granulation can be regarded as the gathering together of cells through cell-to-cell immobilization to form a stable, contiguous, multicellular association. These aggregated granules have a compact structure as compared with suspended sludge flocs. Studies show that aerobic granulation is a gradual process from seed sludge to compact aggregates, further to granular sludge and finally to mature granules. For cells in a culture to aggregate, a number of factors could affect this process. Aerobic granules can grow on a wide variety of organic substrates in sequencing batch reactor (SBR), including glucose, acetate, ethanol, phenol, particulate organic matter-rich wastewater, soybean-processing wastewater, and both simulated and real municipal wastewater. Aerobic granules is a process independent of or insensitive to the characteristics of feed wastewater, while evidence shows that the microbial structure and diversity of mature aerobic granules are closely related to the type of substrates used. Aerobic granulation in SBR is substrate concentration-independent, but the kinetics behavior of aerobic granules is related to the applied substrate loading. Similar to the formation of a biofilm, aerobic granules can form at different levels of hydrodynamic shear forces. As a result, hydrodynamic shear force is not a primary inducer of aerobic granulation in SBR.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 6 Structure of aerobically grown microbial granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter focuses on the structure of aerobically grown microbial granules. Microbial granule, called “mycetoma” or “sclerotia,” can be formed inside the body of humans or animals. It is a spherical or ellipsoidal aggregate of slow-growing bacterial cells or fungal mycelium in the infected body part. These spherical granules are formed, probably, because of microbial growth in dense tissue, which is a pressing aggregate of microbial cells evenly from all directions. Current interest to aerobically grown microbial granules is related to their formation during wastewater treatment in sequencing batch reactors (SBR). Aerobically grown microbial granules are actively investigated as bioagents for the biological treatment of wastewater. The features of aerobically grown microbial granules, which are used in wastewater treatment, are spherical or ellipsoidal shape, sometimes they can be elongated so that they are rod-like, they have size ranging from 0.2–7 mm, have filamentous, smooth, or skin-like surface, which is dominantly hydrophobic or hydrophilic, and have a gel-like interior (matrix). They also consist of layers and microaggregates of specific microorganisms, several channels and pores, and the inclusions of particulates. Typical shapes of the granules are sphere or ellipsoid. The roundness is evaluated by the ratio of the shortest and longest axis of ellipsoid.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 7 Microorganisms of aerobic microbial granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter presents an overview of the microorganisms of aerobic microbial granules. Aerobically grown microbial granules are aggregates which are specified with regular shape (spherical, egg-shaped, or elongated oval in cross section); with size from 0.5 to several mm; with high-settling velocity from 0.2–2 cm/s; and with high density and sludge-to-volume index (SVI) ranging from 20–80 g/l. The observation of the different growth stages of aerobic granules implies that the development of aerobic granules might go through a sequence of specific, but poorly understood, chemical and biological processes. Aerobically grown microbial granules contain obligate anaerobe Bacteroides spp. These bacteria usually dominate in human feces. The source of the initial inoculation of aerobic microbial flocs in wastewater treatment plant by Bacteroides spp. is the raw sewage or the effluent from anaerobic digester. Ecological consequence from the detection of obligate anaerobic bacteria in aerobically grown granule is that the boundary of anaerobic microzone in microbial matrix of the granule or thick biofilm can be detected by the visualization of the layer of Bacteroides spp., or other anaerobic microorganisms by FISH with specific fluorescence-labeled oligonucleotide probe. This method reliably shows the place of anaerobic layer, which depends on average oxygen gradient during the microbial granule growth and activity.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 8 Nutrient removal by microbial granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter focuses on the mechanism of nutrient removal by microbial granules. Nitrogen and phosphorus are key nutrients causing eutrophication in water body and they are required to be removed from water resources in many countries. Biological nutrient removal (BNR) can be accomplished by nitrification, denitrification, and enhanced biological phosphorus removal (EBPR). However, these systems often encounter several difficulties, including sludge bulking because of the proliferation of filamentous organisms, requirement for a long sludge age to ensure stable nitrification, and requirement for a large space if multistage systems are employed. In the past few years, aerobic granules for organic carbon removal have been developed in sequencing batch reactors (SBR). Compared to conventional activated sludge flocs, aerobic granular sludge has a regular, dense, and strong physical structure, good settling ability, high biomass retention, and the ability to withstand shock load. Evidence shows that the problems encountered in the suspended growth nutrient-removal system can be overcome by developing and applying N-removing and P-accumulating granules. A more compact and efficient granule-based biotechnology would be expected for high-efficiency N and P removal. This chapter presents detailed information with regard to the development of microbial granules for the nutrient removal processes.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 9 Removal of phenol from wastewater by microbial granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter analyzes the removal of phenol from wastewater by microbial granules. Phenol is an important industrial chemical and is used in the production of polycarbonate resins, explosives, paints, inks, perfumes, wood preservatives, textiles, drugs, and as an antibacterial and antifungal agent. Because of its widespread use and its ubiquity, phenol is a major pollutant of the environment. In view of the widespread occurrence of phenol, microorganisms can be found in many environments that are able to use phenol as a carbon and energy source. Aerobic degradation of phenol by microorganisms is mainly based on the ortho- and meta-cleavage pathways. During the first step of the aerobic phenol degradation pathway, molecular oxygen is used by the phenol hydroxylase enzyme to add a second hydroxyl group in the ortho-position to the one already present to produce catechol, which can then be degraded by either the ortho- or the metacleavage pathways. In aerobic phenol degradation, the highly reactive molecular oxygen is used for the initial attack on the aromatic ring and for the final ring cleavage step. Pure cultures of anaerobically respiring bacteria can completely oxidize phenol to carbon dioxide using nitrate, ferric iron, or sulfate as terminal electron acceptor. At least two phenol degradation pathways have been suggested to occur under methanogenic conditions.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 10 Seeds for aerobic microbial granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter focuses on the seeding process for aerobic microbial granules. Microbial granulation is a process exploited in biological wastewater treatment whereby bacteria are organized into highly structured suspended granules that are capable of removing biodegradable organic matter, nitrogen, and phosphorus. The addition of previously grown microbial biomass as starter culture is a common approach in wastewater treatment plants to start up the conventional activated sludge and anaerobic digestion processes after technological accidents or process failure. Therefore, similar approach can be used to start up the process with granulated microbial biomass. There are some known commercial application of the granules as the seeds to upgrade or initiate wastewater treatment, for example, product ARGUS consisting of granules used as seeds for biological treatment of wastewater from chemical, pharmaceutical, and food industries, as well as oil refineries, landfills, pig, and poultry farms in cases that existing treatment plant is not working properly and should be upgraded and in new plants for the treatment of complex and toxic chemicals. Studies also suggest that it is better for stable wastewater treatment process to use particles from disrupted granules as the seeds to ensure their further growth to matured and stable granules.

      PubDate: 2012-12-15T09:51:58Z
       
  • Chapter 11 Biosorption properties of aerobic granules
    • Abstract: 2006
      Publication year: 2006
      Source:Waste Management Series, Volume 6

      This chapter focuses on the biosoroption properties of aerobic granules. Aerobic granulation is an innovative biotechnology. Aerobic granules are microbial aggregates with strong and compact microbial structure and settling velocity and density of aerobic granules are much higher than conventional bioflocs. The chapter presents a study in which the biosorption of Cd2+ by aerobic granules was tested. The biosorption profiles of cadmium at different initial cadmium concentrations (Co), indicated that about 50% of the amount of adsorbed cadmium at equilibrium was removed in the first 1 h of the test and the biosorption equilibrium was gradually achieved in 3 h. When the initial granules concentration was constant, the increased Cd2+ concentration led to an increase in the Cd2+ uptake capacity from 38.2 mg Cd2+/g granules at 10mg/l Cd2+ to 99.8 mg Cd2+/g granules at 150mg/1 Cd2+. The chapter shows the biosorption profiles of copper at different initial copper concentrations with a fixed granules concentration of 100 mg/1. The biosorption behaviors of copper at different initial granules concentration with a constant initial copper concentration of 100 mg/1 is also shown in the chapter.

      PubDate: 2012-12-15T09:51:58Z
       
 
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