Leaching Of Arsenic And Selenium From Fly Ash In The Simulated Field Systems

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Leaching of Arsenic and Selenium from Fly Ash in the Simulated Field Systems

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Author : Lenin P. Kasthuri
Publisher :
ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.:/5 (832 download)

Book Synopsis Leaching of Arsenic and Selenium from Fly Ash in the Simulated Field Systems by : Lenin P. Kasthuri

Download or read book Leaching of Arsenic and Selenium from Fly Ash in the Simulated Field Systems written by Lenin P. Kasthuri and published by . This book was released on 2006 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Fly ash accounts for nearly 60% of coal combustion products produced in the United States. Although fly ash is beneficially used in the cement and concrete industries, in waste stabilization, and as a structural fill, about 60% is disposed in landfills or ponds. Trace elements of major environmental concern such as As, Se, Hg, Cr, Cd, Ni, Pb, Cu, Co etc end up on fly ash particles as a result of coal combustion, which may be potentially released to the environment. For utilization purposes, fly ash is classified as class C or class F, depending primarily on its Si+Al+Fe content. The westernsub-bituminousminous coal typically produces class C fly ash, which is also higher in calcium than class F fly ash typically produced from eastern bituminous coal. Due to the differences in ash composition, the leaching behavior of trace elements varies between different types of fly ashes. In addition, activated carbon and ammonia may be used in power plants to control mercury and NOx emission, which also may affect trace element leaching. This study focused on the leaching potential of two major oxyanions of concern, arsenic and selenium, from different fly ashes under simulated field conditions. The results indicated that As and Se, which occur primarily as anionic species in water, were less leachable from the class C ash compared to the class F ash, at least partially due to the higher calcium content in the class C ash. Results also indicated that the mixing of class C ash and class F ash can significantly reduce the leaching of arsenic compared to the Class F ash alone. Activated carbon and ammonia based technologies do not seem to change the leaching characteristics of both arsenic and selenium from fly ash under natural conditions"--Abstract, leaf iv.

The Leaching Behavior of Arsenic, Selenium and Other Trace Elements in Coal Fly Ash

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Author : Tian Wang
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (233 download)

Book Synopsis The Leaching Behavior of Arsenic, Selenium and Other Trace Elements in Coal Fly Ash by : Tian Wang

Download or read book The Leaching Behavior of Arsenic, Selenium and Other Trace Elements in Coal Fly Ash written by Tian Wang and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The goals of this study are four fold, they are: (1) to investigate the leaching behavior of arsenic and selenium from fly ash as well as their affecting factors; (2) to analyze the speciation of arsenic and selenium in fly ash leachate; (3) to develop a modeling approach to quantify the availability and stability of trace cationic elements in fly ash; (4) to apply this model to describe the leaching/adsorption behavior of arsenic and selenium on fly ash, as well as the calcium effect on arsenic (V) adsorption process"--Abstract, leaf iv

Leaching Characteristics of Inorganic Contaminants from Coal Fly Ash

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Author : Tingzhi Su
Publisher :
ISBN 13 :
Total Pages : 446 pages
Book Rating : 4.:/5 (87 download)

Book Synopsis Leaching Characteristics of Inorganic Contaminants from Coal Fly Ash by : Tingzhi Su

Download or read book Leaching Characteristics of Inorganic Contaminants from Coal Fly Ash written by Tingzhi Su and published by . This book was released on 2011 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Leaching of trace elements raises environmental concerns in coal fly ash disposal and reuse. US EPA is in the process of creating the first national rule on coal ash management. However, due to the complexity of coal fly ash composition, the leaching characteristics of trace elements are not well understood. Meanwhile, driven by the tightening emission regulations, new types of coal fly ashes are continuously generated as a result of the technological evolution at coal energy industry. The changing landscape highlights the needs for a comprehensive database to assess the leaching characteristics of different types of coal fly ashes, evaluation of the emission control technology on the ashes produced in the power industry, a practical method to predict the leachability of trace contaminants, and effective methods to remediate inorganic contaminants in fly ash. This study investigated the leaching of a group of concerned inorganic contaminants from different types of fly ashes, and assessed the impact of trona inject for SO2 emission control at coal combustion plants on the fly ash produced. The results showed that trona injection greatly changed the fly ash physical and chemical composition, and significantly enhanced the leaching characteristics of oxyanionic trace elements, especially arsenic (As) and selenium (Se). A protocol was developed to quantify the availability and stability of As and Se in raw bituminous fly ash under various field conditions. The effectiveness of EDT A-washing in remediating fly ash was studied, and the results demonstrated promising application of EDT A in removing toxic trace elements, including As and Se, from low-Ca coal fly ashes"--Abstract, leaf iv.

Leaching Characteristics of Selenium from Coal Fly Ash

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Author : Mark Allen Cantrell
Publisher :
ISBN 13 : 9781303824548
Total Pages : 286 pages
Book Rating : 4.8/5 (245 download)

Book Synopsis Leaching Characteristics of Selenium from Coal Fly Ash by : Mark Allen Cantrell

Download or read book Leaching Characteristics of Selenium from Coal Fly Ash written by Mark Allen Cantrell and published by . This book was released on 2014 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Selenium (Se) contamination can be a potential groundwater concern near un-lined coal ash landfills. Out of all the Environmental Protection Agency (EPA) priority and non-priority pollutants, Se has the narrowest range between what is considered beneficial and detrimental for aquatic and terrestrial organisms. The effects of ash type (i.e., fresh and weathered), water-extractant type (i.e., deionized water, rainwater, and groundwater), and extraction time (i.e., 2- and 6-hours) on Se, arsenic (As), and chromium (Cr) concentrations were investigated from Class C, subbituminous coal fly ash produced at the Flint Creek Power Plant located in Benton County, AR. Water-extractable Se concentrations differed (P = 0.03) between ash types across water-extractants, but were unaffected by extraction times. Unexpectedly, fresh ash water-extractable Se concentrations were below minimum detection limits (i.e., 2.0 mug L−1) for all treatments. In contrast, averaged over extraction times, the weathered ash water-extractable Se concentration was greatest (P

Part I: Increased Leaching of Arsenic, Selenium, Molybdenum, and Vanadium from High Calcium Coal Ash Containing Trona Reaction Products. Part II: Using Agricultural Byproduct Rice Hull as Biosorbent to Remove and Recover Metal Ions in Water

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Author : Yongbo Dan
Publisher :
ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.:/5 (96 download)

Book Synopsis Part I: Increased Leaching of Arsenic, Selenium, Molybdenum, and Vanadium from High Calcium Coal Ash Containing Trona Reaction Products. Part II: Using Agricultural Byproduct Rice Hull as Biosorbent to Remove and Recover Metal Ions in Water by : Yongbo Dan

Download or read book Part I: Increased Leaching of Arsenic, Selenium, Molybdenum, and Vanadium from High Calcium Coal Ash Containing Trona Reaction Products. Part II: Using Agricultural Byproduct Rice Hull as Biosorbent to Remove and Recover Metal Ions in Water written by Yongbo Dan and published by . This book was released on 2013 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Part I. The trona is being injected to control SO[subscript x] emission from coal-fired power plants. The results showed that trona ash leached significantly more As, Se, Mo, and V than the control fly ash did, especially under the natural pH condition. In addition, trona ash had a significantly greater soluble fraction than the control ash. Further investigation indicated that greater amounts of the studied anionic elements in the trona ash were associated with the soluble, trona reaction products. Moreover, the insoluble fraction of the trona ash lost its capability to adsorb these elements under the natural pH condition. The competition from other major anions in the trona ash leachate might also have contributed to the reduced adsorption of the trace anionic elements under other pH conditions. Part II. Untreated rice hull showed very good removal of Pb, Ag, Cd and Cu, but the removal efficiencies for the other elements was relatively low. Sodium hydroxide treatment significantly improved the removal efficiency for all metal elements tested. The pH affected the removal significantly. It is believed that the electrostatic attraction between negatively charged rice hull and positively charged metal elements is the principal removal mechanism, though the other factors may also play some roles. Adsorption kinetics was found very fast. For the fast kinetics metal ions, removal efficiency in column format was higher than that in batch format. However, for others, removal efficiency in column format was lower than that in batch format because of short contact time between rice hull and metal ions. Rice hull was successfully employed for metal elements removal in surface water sample. Due to the other content in the real water sample, the removal efficiency was lower than that in reagent water matrix"--Abstract, leaf iv.

Part I

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Author : Yongbo Dan
Publisher :
ISBN 13 :
Total Pages : 61 pages
Book Rating : 4.:/5 (96 download)

Book Synopsis Part I by : Yongbo Dan

Download or read book Part I written by Yongbo Dan and published by . This book was released on 2013 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Part I. The trona is being injected to control SO[subscript x] emission from coal-fired power plants. The results showed that trona ash leached significantly more As, Se, Mo, and V than the control fly ash did, especially under the natural pH condition. In addition, trona ash had a significantly greater soluble fraction than the control ash. Further investigation indicated that greater amounts of the studied anionic elements in the trona ash were associated with the soluble, trona reaction products. Moreover, the insoluble fraction of the trona ash lost its capability to adsorb these elements under the natural pH condition. The competition from other major anions in the trona ash leachate might also have contributed to the reduced adsorption of the trace anionic elements under other pH conditions. Part II. Untreated rice hull showed very good removal of Pb, Ag, Cd and Cu, but the removal efficiencies for the other elements was relatively low. Sodium hydroxide treatment significantly improved the removal efficiency for all metal elements tested. The pH affected the removal significantly. It is believed that the electrostatic attraction between negatively charged rice hull and positively charged metal elements is the principal removal mechanism, though the other factors may also play some roles. Adsorption kinetics was found very fast. For the fast kinetics metal ions, removal efficiency in column format was higher than that in batch format. However, for others, removal efficiency in column format was lower than that in batch format because of short contact time between rice hull and metal ions. Rice hull was successfully employed for metal elements removal in surface water sample. Due to the other content in the real water sample, the removal efficiency was lower than that in reagent water matrix"--Abstract, page iv.

Proceedings

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Author :
Publisher :
ISBN 13 :
Total Pages : 464 pages
Book Rating : 4.4/5 (898 download)

Book Synopsis Proceedings by :

Download or read book Proceedings written by and published by . This book was released on 1980 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Chemical Stabilization of Coal Fly Ash for Simultaneous Suppressing of As, B, and Se Leaching

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Author : Sri Hartuti
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (115 download)

Book Synopsis Chemical Stabilization of Coal Fly Ash for Simultaneous Suppressing of As, B, and Se Leaching by : Sri Hartuti

Download or read book Chemical Stabilization of Coal Fly Ash for Simultaneous Suppressing of As, B, and Se Leaching written by Sri Hartuti and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The discard of coal fly ash produced from the combustion of pulverized coal in a coal-fired boiler of thermal power plants has led to environmental concerns. Due to the interaction of fly ash particles with weathering and hydrological processes, the rainfall leaches out toxic elements in coal fly ash from the ash heaps. This situation has been pointed out as a potential contamination of soil, surface, and groundwater. In this chapter, the available fly ash treatment techniques to minimize future release of toxic trace elements (arsenic, boron, and selenium) have been documented, and the recent investigations dealing with leaching suppression effect of arsenic, boron, and selenium from coal fly ash have been reviewed. The leaching characteristics of arsenic, boron, and selenium are discussed, and a simple and low-cost leaching control method is presented in the context of treating the fly ash through chemical stabilization technique using additives containing high levels of calcium. Experimental results described in this chapter show the chemical stabilization technique utilizing Ca-containing additives is an effective technique for simultaneous suppressing of As, B, and Se leaching from coal fly ash.

Trace Metal Control for Fly Ash Through Attenuation and Solidification

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Author : Gautham Parangusa Das
Publisher :
ISBN 13 :
Total Pages : 366 pages
Book Rating : 4.:/5 (841 download)

Book Synopsis Trace Metal Control for Fly Ash Through Attenuation and Solidification by : Gautham Parangusa Das

Download or read book Trace Metal Control for Fly Ash Through Attenuation and Solidification written by Gautham Parangusa Das and published by . This book was released on 2004 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to investigate two different approaches for controlling trace metals that leach from coal combustion fly ash. In particular, one part of the research program consisted of a systematic evaluation of an array of sorbents for possible use as permeable reactive material. The second part of the research considered the use of mixtures of lime, fly ash, and flue gas desulfurization material (FGD) to stabilize the ash and reduce leachability. To assess the ability of the additives to attenuate heavy metals, batch and column sorption tests were conducted. The methodology involved screening a wide variety of low cost (e.g., steel byproducts, rubber dust, compost) and innovative materials (e.g., kudzu, biofilm, pondweed) as well as conventional additives (activated carbon and alumina, zeolites) for benchmarking purposes. Promising additives included limestone and steel byproducts. In the case of limestone, batch sorption studies revealed large distribution coefficients (K[subscript]d) of 15,740, 1520 and 540 L/kg, for cadmium, chromium and selenium, respectively. However, subsequent column testing yielded K[subscript]d values less than 10 L/kg, suggesting a kinetic limitation on the reaction mechanism for the flow rates investigated. Solidification was investigated on both laboratory and field-scales, where fly ash blended with varying amounts of lime was subjected to various leach procedures. Leaching results showed that arsenic leached below the reporting limit (10 [mu]g/L) for fly ash alone, while the 0.50% lime amendment increased the leachability to nearly 50 [mu]g/L. There is a threshold level of lime amendment, beneath which may result in an increase in pH and leachability of oxyanions such as arsenic, chromium, and selenium. Sufficient lime must be added to engender the cementitious reactions which are responsible for immobilizing contaminants.

Transportation Research Record

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Author :
Publisher :
ISBN 13 :
Total Pages : 596 pages
Book Rating : 4.3/5 (555 download)

Book Synopsis Transportation Research Record by :

Download or read book Transportation Research Record written by and published by . This book was released on 1995 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: "For more than 50 years, the Transportation Research Record has been internationally recognized as one of the preeminent peer-reviewed journals for transportation research papers from authors in the United States and from around the world. One of the most cited transportation journals, the TRR offers unparalleled depth and breadth in the coverage of transportation topics from both academic and practitioner perspectives. All modes of passenger and freight transportation are addressed in papers covering a wide array of disciplines, including policy, planning, administration, economics and financing, operations, construction, design, maintenance, safety, and more."--Publisher's website

The Department of Energy's FY 1997 Budget Request for the Office of Energy Research (OER)

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Author : United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment
Publisher :
ISBN 13 :
Total Pages : 1348 pages
Book Rating : 4.3/5 (121 download)

Book Synopsis The Department of Energy's FY 1997 Budget Request for the Office of Energy Research (OER) by : United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment

Download or read book The Department of Energy's FY 1997 Budget Request for the Office of Energy Research (OER) written by United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment and published by . This book was released on 1996 with total page 1348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Small Business Innovation Research

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Author : DIANE Publishing Company
Publisher : DIANE Publishing
ISBN 13 : 9780788103766
Total Pages : 130 pages
Book Rating : 4.1/5 (37 download)

Book Synopsis Small Business Innovation Research by : DIANE Publishing Company

Download or read book Small Business Innovation Research written by DIANE Publishing Company and published by DIANE Publishing. This book was released on 1994 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Managing Coal Combustion Residues in Mines

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Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 0309100496
Total Pages : 273 pages
Book Rating : 4.3/5 (91 download)

Book Synopsis Managing Coal Combustion Residues in Mines by : National Research Council

Download or read book Managing Coal Combustion Residues in Mines written by National Research Council and published by National Academies Press. This book was released on 2006-08-14 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Burning coal in electric utility plants produces, in addition to power, residues that contain constituents which may be harmful to the environment. The management of large volumes of coal combustion residues (CCRs) is a challenge for utilities, because they must either place the CCRs in landfills, surface impoundments, or mines, or find alternative uses for the material. This study focuses on the placement of CCRs in active and abandoned coal mines. The committee believes that placement of CCRs in mines as part of the reclamation process may be a viable option for the disposal of this material as long as the placement is properly planned and carried out in a manner that avoids significant adverse environmental and health impacts. This report discusses a variety of steps that are involved in planning and managing the use of CCRs as minefills, including an integrated process of CCR characterization and site characterization, management and engineering design of placement activities, and design and implementation of monitoring to reduce the risk of contamination moving from the mine site to the ambient environment. Enforceable federal standards are needed for the disposal of CCRs in minefills to ensure that states have adequate, explicit authority and that they implement minimum safeguards.

Fossil Energy Update

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Author :
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ISBN 13 :
Total Pages : 790 pages
Book Rating : 4.:/5 (31 download)

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Download or read book Fossil Energy Update written by and published by . This book was released on 1978 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Leachate Control of Coal Fly Ash Through Hydrophobicity and Contaminant Fixation

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Author : Jenet Truelsen Hattaway
Publisher :
ISBN 13 :
Total Pages : 326 pages
Book Rating : 4.:/5 (889 download)

Book Synopsis Leachate Control of Coal Fly Ash Through Hydrophobicity and Contaminant Fixation by : Jenet Truelsen Hattaway

Download or read book Leachate Control of Coal Fly Ash Through Hydrophobicity and Contaminant Fixation written by Jenet Truelsen Hattaway and published by . This book was released on 2014 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research study was to determine whether the leaching of metals from coal fly ash can be reduced or eliminated by increasing hydrophobicity (water repellency) or contaminant fixation in fly ash. A secondary goal was determining how the newer EPA leaching tests compare with the Resource Conservation and Recovery Act (RCRA) specified Toxicity Characteristic Leaching Procedure (TCLP). Coal fly ash (CFA) is a product of coal combustion that is captured by air pollution control devices. The consistency and physical properties of fly ash make it a valuable substitute for a number of construction components such as road base, structural fill and as a partial substitute for cement in concrete mixtures. However, concerns that metals present in fly ash may leach and migrate into water supplies impacted the expanded use of coal fly ash. Millions of tons of fly ash are produced each year during electric power production and only 42% is recycled, primarily into concrete. Leaching occurs when water in contact with a solid material causes the solid to release some of its constituents into the contacting water. If water can be prevented from contacting the fly ash, leaching should not occur. Organosilanes (OS) are a family of chemicals that facilitate covalent bonding and render surfaces water repellent. Two different OS products were tested in this study as a method of imparting hydrophobicity to the fly ash. A contaminant fixation product, to sequester the metals in chemical bonds, was the third treatment tested. Treated and untreated coal fly ash was tested according to four different leaching procedures, methods 1311, 1313, 1314 and 1316 of the U.S. Environmental Protection Agency's "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods" also known as SW-846. Method 1311 (TCLP) is the established leaching test used for regulatory screening to determine toxicity. Method 1311 was compared with Methods 1313, 1314, and 1316. The leachates were analyzed for seventeen metals: Aluminum, Arsenic, Barium, Boron, Cadmium, Calcium, Chromium, Copper, Iron, Lead, Magnesium, Manganese, Molybdenum, Selenium, Silicon, Vanadium, and Zinc. While no treatment tested prevented leachability of all constituents in this battery of leaching tests, different treatments were effective in reducing leaching of different constituents. For example, one OS treatment reduced arsenic concentrations 24% to 72% within the pH range of 5.5 to 10.5. This suggests that a chemical treatment may be developed that can prevent or reduce leachability. Analysis indicates that treatment efficacy varies with pH, test method and the metal analyzed. The extent to which these leaching results accurately reflect likely field performance remains unclear. Methods 1313, 1314 and 1316 provide more information about the leaching behavior of a material and may provide more appropriate regulatory guidance than Method 1311 (TCLP) if used with applicable environmental conditions rather than a blanket "worse case" scenario. The comparison also highlighted that Method 1311 (TCLP) may under report leaching concentrations for such elements as arsenic, selenium, and molybdenum when the material has a high natural pH.

Flue Gas Desulfurization and Industrial Minerals

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Author : M. Michael Miller
Publisher :
ISBN 13 :
Total Pages : 720 pages
Book Rating : 4.3/5 (243 download)

Book Synopsis Flue Gas Desulfurization and Industrial Minerals by : M. Michael Miller

Download or read book Flue Gas Desulfurization and Industrial Minerals written by M. Michael Miller and published by . This book was released on 1993 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains 4,101 references on FGD [Flue Gas Desulfurization] ... primarily from 1982 through June 1993. Complements the "Flue Gas Desulfurization and Denitrification" bibliography published by the U.S. Dept. of Energy in Jan. 1985. References were located on the Energy, Science and Technology, Pollution Abstracts, and Environmental Bibliography databases. Primarily covers FGD and the use of industrial minerals in the desulfurization process or in by-product utilization and disposal. Emphasizes post-combustion removal of sulfur dioxide through processes such as in-duct injection and wet and dry scrubbing.

Scientific and Technical Aerospace Reports

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Author :
Publisher :
ISBN 13 :
Total Pages : 1368 pages
Book Rating : 4.:/5 (31 download)

Book Synopsis Scientific and Technical Aerospace Reports by :

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 1368 pages. Available in PDF, EPUB and Kindle. Book excerpt: