Waste Management Practices 2nd Edition John Pichtel - Solutions

Suppose your community has decided to develop a waste management program with a goal of substantially greater waste recycling and materials recovery. The three major alternatives are source separation, a dirty MRF, and a clean MRF. Discuss the key factors to consider in order to identify the
It is undesirable to land-apply raw solid wastes to soil because undesirable reactions may occur, which could inhibit plant growth. Explain.
When a waste possessing a high C:N ratio (200:1) is land-applied: (a) microbial growth is relatively unchanged, (b) agricultural plants cannot compete with soil microbes for soil N, (c) N is converted into ammonia gas (NH3) and lost to the atmosphere, (d) nitrogen is converted to N2 gas.
During the composting of MSW, a series of complex N transformations, including immobilization, nitrification, mineralization, and others occur. Explain how the C:N ratio declines during composting. What are the fates of N and C? Provide specific reactions.
Microbial succession is important to bring the composting process to completion. Explain.
Explain how fire could be generated in an actively composting pile. How could such a scenario be prevented?
Compare the dynamics of microbial populations, oxygen levels, and temperature over time with the turned pile method of composting versus aerated static piles.
Discuss the pH requirements for optimizing composting. Why, from a biochemical or microbiological perspective, is this pH range most effective?
Composting of sewage sludge poses different management concerns compared with composting of MSW. Describe how the process may differ in terms of pathogen control, odor control, leachate control, and aeration.
Explain how anaerobic reactions may occur in a compost pile that contains 15%-20%oxygen in the interstitial spaces.
What is the relationship between pile temperature and microbial growth and activity?What is an ideal compost temperature range? Why is this range considered optimal?
The city of Pristine, IL, in developing their comprehensive waste management program, will establish a composting facility adjacent to the transfer station. What attributes should be considered when screening potential locations for a composting site? Consider size of area, soils, drainage and
The land area of the selected compost site is smaller than optimum. Based on practical issues, the following compost method should be used: (a) turned pile, (b) static pile with forced aeration, (c) sheet composting, (d) on-the-shelf heated bins, (e) avoid composting altogether and land-apply the
Is there a large-scale MSW composting program operating in your community? What are the feedstock materials? Where is the facility located; for example, adjacent to the transfer station or landfill? On privately owned land? How are odors and leachate production managed?
List and discuss the possible uses for finished compost. What are the benefits of MSW composting in a community integrated waste management program? Given the time, space requirements, energy and labor requirements, is composting economically justified for a community?
For decades, the market value of compost has been quite low. However, many communities continue to support yard waste composting programs. Explain why this is so.
Bench scale tests of aerobic composting were conducted on a feedstock with the starting empirical formula C28H46O22N. Pilot tests indicated that 1000 kg dry solids of the feedstock decreased to 245 kg dry solids by completion. The final product empirical formula was determined to be C12H16O6N.
At a waste-handling facility, a mixture of approximately 70 metric tons of food waste and yard waste is to be composted. The moisture content of the feedstock measures 5.5%. It has been previously determined that an ideal moisture content for the compost pile should be about 58%. Calculate the
Determine the direction of groundwater flow and draw directional arrows.
Observe the data for groundwater quality in the site wells. Are there any constituents that are in excess of maximum contaminant levels (see Table 10.1, also the Code of Federal Regulations)?
Based on groundwater data, can you suggest the plots and waste types that may be contributing to the highest levels of contamination?
Do you observe any correlation between concentrations of any of the contaminants in groundwater?
In the groundwater, does the EC correlate with data for any elements or compounds?
As mentioned above, MSW2 contained relatively higher concentrations of metals compared with other feedstocks. Why were these metals detected only at very low levels in the soil or groundwater?
If we were to assume that the soils were similar from both sites, which compost feedstock results in the lowest NO3− concentrations in groundwater? The highest concentrations?
From the data, what is the general relationship between soil data for NO3− and groundwater data for NO3−? For NH4+? For metals?
This study was not a strictly scientific one; however, conduct an Analysis of Variance(ANOVA) on soil data and determine whether any of the treatments is significantly different in terms of NO3− content, P, or K levels.
Conduct an ANOVA on groundwater data and determine whether any of the treatments is significantly different in terms of NO3− contamination of groundwater.
What corrective measures would you propose in order to control the excess leaching of nutrients from any of these sites?
MSW combustion involves physical and chemical transformations in which solid materials are converted into gases and some solid residues. What factors affect the types of gases produced? What factors influence the quantity of solid residues, both carbonaceous and inorganic?
Compare the operation of a mass-burn incinerator with that of a RDF-burning facility, in terms of: fuel types; waste processing operations and equipment; convenience; resource recovery; energy utilization.
What are the functions of combustion chamber overfire and underfire air? How can they be adjusted to optimize incineration?
List the engineering and design factors that serve to enhance MSW combustion in an incinerator.
Define stoichiometric air and heat value.
Discuss the major gaseous emissions from a mass-burn incinerator and how each may be effectively removed from the flue.
SO2 production may be controlled during mass-burn incineration by addition of limestone directly to the combustion chamber. What are the advantages and disadvantages of this procedure over flue gas desulfurization?
An incinerator operating at a sufficiently high temperature and air inflow rate may still generate PICs. Explain how such a phenomenon may occur.
How do PCDDs and PCDFs form during mass-burn incineration (given that the firebox temperature is sufficiently high, for example, >1000°C, to destroy virtually all organic compounds)? In what physical form(s) are these compounds emitted?
Describe particulate matter as relates to MSW combustion. What are its chemical and physical properties? What size range of particulates are the most potentially damaging when inhaled? How do certain toxins (e.g., metallic vapors, chlorinated hydrocarbons)react with particulate matter to increase
Generation of atmospheric pollutants is directly related to MSW charge rate and combustion chamber conditions, among other factors. Explain.
Explain how the following air pollutants can be removed from stack gases: SO2, particulates, mercury, and PCDDs.
Explain why the majority of MSW incinerators in the United States are mass-burn rather than RDF-fired.
How do electrostatic precipitators and cyclone separators differ in terms of efficiency of removal of particulate matter, SO2, and PCDDs.
Cd occurring in raw MSW can become significantly more soluble (and hence more leachable)following MSW combustion in a mass-burn incinerator. Explain.
Discuss the major concern(s) with RDF storage, both indoors and outdoors.
Which of the following is a significant concern when considering RDF production and utilization with coal: (a) dust production; (b) odor production; (c) separation of RDF and coal during handling; (d) some plants are unable to market the RDF; (e) all of the above.
For RDF to produce the same amount of heat as coal, more ash will probably be produced.Explain.
Compare and contrast RDF and raw MSW in terms of fuel properties. How do they differ in heat content, moisture content, density, and ash content?
How do RDF and coal differ regarding emissions of SO2, NOx, and HCl? How do they differ in ash composition?
A materials recovery facility is being installed in Pristine, IL (pop. 110,000). The MRF will be receiving mixed MSW. RDF will be produced. For maximum efficiency and ease of mixing with coal, what form (e.g., fluff, wet-pulped, densified, etc.) of RDF is recommended?
How will the RDF be stored: (a) in the customers’ yard for easy utilization; (b) in a covered pole barn; (c) no need to store the RDF as it will be immediately sent to market; (d) in 50:50 mixtures with coal in customers’ yard.
An incinerator burns 120 MT/h of MSW with the formula C285H455O235N4S. How much air is needed to completely combust this waste? A rate of 35% excess air is used during combustion.
Calculate the heating value for the waste discussed in Question 23.
List and discuss the passive approaches to landfill gas removal.
What is the minimum landfill CH4 concentration that poses an explosion hazard? At what concentration is methane of possible commercial (heating) value?
Under RCRA, new landfills cannot be located in seismic zones unless the operator can demonstrate that all containment structures (e.g., liners) are designed to resist the maximum horizontal shifting (true or false).
Landfill bird hazards to airports can be limited to a certain extent by shredding and baling MSW prior to disposal. Explain.
Landfill sizing is affected by the desired landfill lifetime, population served, and shape and height of the landfill, among other factors. Explain.
What chemical changes occur during earliest anaerobic stage of decomposition in a sanitary landfill? Discuss in terms of pH, BOD, and transformations of metals.
Methanogenic microorganisms prefer what specific environmental conditions? How do they respond to pH?
What factors influence methane gas migration below the land surface? Consider soil texture, soil temperature, soil moisture, and barometric pressure.
What waste types are restricted from sanitary landfills under current federal regulations?Be specific.
What is the significance of saturated hydraulic conductivity (Ks) in assessing soil for landfill liners and caps, and as landfill foundation? How is Ks influenced by soil texture and engineering practices (e.g., compaction)? What is the RCRA limit for liner Ks?
RCRA calls for stringent controls in MSWLF operation for air quality, explosive gases, stormwater runoff, wetlands protection, cover material, and vectors. Discuss the specific requirements for each.
Geomembrane installation practices may influence future losses of leachate. List and discuss the factors that must be considered for successful geomembrane installation.
Explain the various phases of MSW decomposition in a closed landfill cell. How do leachate quality and gas composition differ between each phase?
Under what conditions is passive landfill gas control acceptable? When is active gas control a requirement?
How does landfill gas differ from utility-grade natural gas in terms of chemical composition?How must landfill gas be processed to render it suitable for sale to an energy utility?
If stormwater enters a landfill unit and contacts waste, how does its regulatory designation change (i.e., according to RCRA)—is it considered nonhazardous, hazardous, special waste, or another designation? How is it to be managed?
RCRA regulations require that bulk or noncontainerized liquid wastes are not to be placed in MSWLFs, with two exceptions. What are they?
Landfill leachates vary in terms of physical characteristics, inorganic and organic composition, microbial populations, and toxicity. How are the above variables affected by waste type and by age in the landfill cell?
Subtitle D requires, at the time of landfill closure, the installation of a final cover (cap)system. What are the primary purposes of the cover? Consider erosion, subsidence, and limiting leachate production.
What are the subtitle D requirements for proper landfill cover design and construction?
How does landfill reclamation occur, i.e., what mechanical steps are required for successful reclamation? How is reclamation beneficial in terms of extending landfill lifetime and enhancing resource recovery?
The Second Law of Thermodynamics states, in essence, that all systems proceed toward maximum disorder (i.e., chaos, entropy). How can a landfill metamorphose over time in the context of the Second Law? In other words, discuss how landfill liners, LCR systems, and caps can be transformed 100 years
Soil material is being assessed as a possible liner for a sanitary landfill. A soil core was collected and brought to the laboratory. A 10 cm tall section of soil has 2 cm of water continuously ponded on it. The area of the core surface is 78 cm2. A total of 62 mL water is collected per hour.
Determine the area required for a new sanitary landfill with a projected lifetime of 20 years. The landfill will serve a population of 175,000 people. It is estimated that per capita waste generation is 1.9 kg/day (4.1 lb/day). Waste density in the landfill averages 625 kg/m3.Landfill height is not
Calculate the annual volume of leachate generated per hectare for a sanitary landfill located along the east coast of the United States. The climate is temperate, average annual rainfall is 122 cm/year (48 in./year), and evapotranspiration is estimated at 48%. The wastes are covered with soil and
Determine the direction of groundwater flow and draw directional arrows.
From the contaminated wells identified, define the extent of any plume and sketch its outline on the map.
Discuss any observable trends in migration of contaminants over the study period.
Based on the behavior of the metals, what can you conclude about the pH of the leachate?
Do the data for chlorinated organics indicate a possible human health hazard? What could be the possible source of these chemicals? Can any arise from natural decomposition of disposed wastes?
Based on groundwater data and the need for additional landfill space, is an extension of this landfill facility justifiable? Give reasons.
What is the top priority for hazardous waste management (general method) under RCRA, and what is the lowest priority?
Which of the following under RCRA is (are) not excluded from the rules and regulations applicable to hazardous waste generators, treatment, storage, disposal, and transportation?(a) domestic sewage, (b) spent nuclear or by-product material, (c) household waste, (d) spent halogenated solvents.
What are acute hazardous wastes? Provide an accurate technical definition.
Which of the following property(ies) is (are) not characteristics that define a RCRA hazardous waste? (a) radioactive, (b) corrosive, (c) ignitable, (d) reactive, (e) biohazard.
What pH range does noncorrosive waste display?
What is the name of the test method used to determine if a waste is toxic? Outline the procedures of the method.
Can a generator legally mix a listed hazardous waste with sufficient nonhazardous solid waste to the point where the mixture is diluted and therefore no longer classified as a hazardous waste? Discuss.
The Hi-Jinx Metalworks Corp. has produced several gallons of spent paint stripper. Based solely on the Material Safety Data Sheet (see following pages), could this waste be a RCRA hazardous waste?
Outside one of the Hi-Jinx warehouses (which had stored paint stripper in the past), several leaking drums are discovered by a state inspector. A sweet solvent odor permeates the air.Is the contaminated soil considered a hazardous waste? Explain.
The environmental safety officer at the Hi-Jinx plant identifies dozens of drums containing a reddish filter cake near the site’s electroplating wastewater treatment plant. After analyzing the filter cake, the level of chromium in the sludge is determined to be 75 mg/kg and the TCLP test measures
Can a waste be both a listed hazardous waste and a characteristic hazardous waste? Explain.
At an automobile body shop and painting facility, metal parts are reworked and repainted, engine components are cleaned and reworked, and fiberglass and metal body parts are repaired and painted. List at least ten different types of waste generated at the facility.Separate into solid (nonhazardous)
List potential sources of hazardous waste generated in your university or company. Name all listed hazardous wastes. To what list(s) do they belong? If they are not listed, what specific characteristics render them hazardous?
Write in the name of each hazardous waste list in the table below: Name of List -List Provide examples of wastes your university generates on this list: -List Provide examples of wastes your university generates: -List Provide examples of wastes your university generates: -List Provide examples of
For the four hazardous waste characteristics, list their hazardous waste numbers: Characteristic EPA Waste Number Ignitable Corrosive Reactive Toxicity characteristic
Define “cradle-to-grave responsibility” for a hazardous waste generator. Discuss the regulatory requirements for packaging, storage, transportation, and manifesting. For how long is the generator responsible for this waste?

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Waste Management Practices 2nd Edition John Pichtel - Solutions

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