File Name: physical chemical and biological characteristics of solid waste .zip
You were introduced to the main types of liquid waste in Study Session 1. This study session is the first of three that builds on that introduction and describes liquid wastes in more detail. We begin with a closer look at the sources and characteristics of liquid wastes.
Degradation of organic wastes in the presence of oxygen by microorganisms and bacteria, releasing carbon dioxide gas and heat and producing solid material compost that can be used as a soil amendment. An example of Aerobic Decomposition is the waste degradation that occurs in a compost pile. See Composting. Contrast Anaerobic Digestion.
The discussion is limited to an analysis of residential, commercial, and some industrial solid wastes. Because the specific weight of MSW is often reported as loose, as found in containers, uncompacted, compacted, and the like, the basis used for the reported values should always be noted. Specific weight data are often needed to assess the total mass and volume of waste that must be managed.
Typical specific weights for various wastes as found in containers, compacted, or uncompacted are reported in Table 3. Table 3. Because the specific weights of solid wastes vary markedly with geographic location, season of the year, and length of time in storage, great care should be used in selecting typical values. In the wet-weight method of measurement, the moisture in a sample is expressed as a percentage of the wet weight of the material; in the dry-weight method, it is expressed as a percentage of the dry weight of the material.
The wet-weight method is used most commonly in the field of solid waste management. The moisture content will vary from 15 to 40 percent, depending on the composition of the wastes, the season of the year, and the humidity and weather conditions, particularly rain.
Example 3. Solution: Set up the computation table to determine dry weights of the solid waste components using the data given in Tabel3. The field capacity of waste materials is of critical importance in determining the formation of leachate in landfills. Water in excess of the field capacity will be released as leachate. For example, the feasibility of combustion depends on the chemical composition of the solid wastes.
If solid wastes are to be used as fuel, the four most important properties to be known are: Proximate analysis. Fusing point of ash Ultimate analysis major elements Energy content 3. Because of the concern over the emission of chlorinated compounds during combustion, the determination of halogens is often included in an ultimate analysis. The results of the ultimate analysis are used to characterize the chemical composition of the organic matter in MSW.
Determine the chemical composition of the organic fraction, without and with sulfur and without and with water, of a residential MSW with the typical composition shown in Table 1. Solution: Set up a computation table to determine the percentage distribution of the major elements composing the waste. Compute the molar composition of the elements neglecting the ash. Determine an approximate chemical formula without and with sulfur and without and with water.
Set up a computation table to determine normalized mole ratios. By using a laboratory bomb calorimeter and By calculation, if the elemental composition is known. Typical data for energy content and inert residue for the components of residential wastes are reported in table below. The Btu values given in the table may be converted to a dry basis by using Eq. Determine the energy value of a typical residential MSW with the average composition shown in Table 1. Solution: Assume the heating value will be computed on an as discarded basis.
Determine the total energy content using the data given in Table 2. The necessary computations are presented below. If Btu values are not available, approximate Btu values for the individual waste materials can be determined by using Eq. Determine the energy value of typical residential MSW with the average composition determined in example 3. Determine the percentage distribution by weight of the elements composing the waste, using coefficients that have been rounded off.
The use of VS in describing the biodegradability of the organic fraction of MSW is misleading, as some of the organic constituents of MSW are highly volatile but low in biodegradability e. The rate at which the various components can be degraded varies markedly.
For practical purposes, the principal organic waste components in MSW are often classified as rapidly and slowly decomposable. The development of odors in on-site storage facilities is more significant in warm climates.
Typically, the formation of odors results from the anaerobic decomposition of the readily decomposable organic components found in MSW. For example, under anaerobic reducing conditions, sulfate can be reduced to sulfide S-2 , which subsequently combines with hydrogen to form H2S The formation of H2S can be illustrated by the following two series of reactions.
If were not for the formation of a variety of sulfides, odor problems at landfills could be quite significant. The biochemical reduction of an organic compound containing a sulfur radical can lead to the formation of malodorous compounds such as methyl mercaptan and amino butyric acid.
The methyl mercaptan can be hydrolyzed biochemically to methyl alcohol and hydrogen sulfide:? Physical transformations do not involve a change in phase e. Component separation is used to transform a heterogeneous waste into a number of more-or-less homogeneous components.
Component separation is a necessary operation in the recovery of reusable and recyclable materials from MSW, in the removal of contaminants from separated materials to improve specifications of the separated material, in the removal of hazardous wastes from MSW, and where energy and conversion products are to be recovered from processed wastes. In most cities, the vehicles used for the collection of solid wastes are equipped with compaction mechanisms to increase the amount of waste collected per trip.
Paper, cardboard, plastics, and aluminum and tin cans removed from MSW for recycling are baled to reduce storage volume, handling costs and shipping costs to processing centers as shown in figure3. At disposal sites solid wastes are compacted to use the available land effectively. The objective of size reduction is to obtain a final product that is reasonably uniform and considerably reduced in size in comparison with its original form.
Note that size reduction does not necessarily imply volume reduction. In some situations, the total volume of the material after size reduction may be greater than that of the original volume e.
All three of these processes are often classified as thermal processes. Combustion chemical oxidation :combustion is defined as the chemical reaction of oxygen with organic materials, to produce oxidized compounds accompanied by the emission of light and rapid generation of heat. The end products derived from the combustion of MSW, Eq.
In practice, small amounts of ammonia NH3. Sulfur dioxide SO2 , nitrogen oxides NOx , and other trace gases will also be present, depending on the nature of the waste materials.
Pyrolysis: Because most organic substances are thermally unstable, they can be split, through a combination of thermal cracking and condensation reactions in an oxygen-free atmosphere, into gaseous, liquid, and solid fractions. In contrast with the combustion process, which is highly exothermic, the pyrolytic process is highly endothermic.
For this reason, destructive distillation is often used as an alternative term for pyrolysis. The characteristics of the three major component fractions resulting from the pyrolysis of the organic portion of MSW are: A gas stream containing primarily hydrogen H2.
Gasification: The gasification process involves partial combustion of a carbonaceous fuel so as to generate a combustible fuel gas rich in carbon monoxide, hydrogen, and some saturated hydrocarbons, principally methane. The combustible fuel gas can then be combusted in an internal combustion engine or boiler.
When a gasifier is operated at atmospheric pressure with air as the oxidant, the end products of the gasification process are: A low-Btu gas typically containing carbon dioxide CO2 , carbon monoxide CO , hydrogen H2 , methane CH4. And nitrogen N2 ; A char containing carbon and the inerts originally in the fuel, and Condensable liquids resembling pyrolytic oil as shown in figure3. The principal organisms involved in the biological transformations of organic wastes are bacteria, fungi, yeasts, and actinomycetes.
These transformations may be accomplished either aerobically or anaerobically depending on the availability of oxygen. The principal differences between the aerobic and anaerobic conversion reactions are the nature of the end products and the fact oxygen must be provided to accomplish the aerobic conversion.
Biological processes that have been used for the conversion of the organic fraction of MSW include aerobic composting, anaerobic digestion, and high-solids anaerobic digestion. The extent and the period of time over which the decomposition occurs will depend on the nature of the waste, the moisture content, the available nutrients, and other environmental factors.
Yard wastes and the organic fraction of MSW can he converted to a stable organic residue known as compost see Fig. Compost is the resistant organic matter that remains. The resistant organic matter usually contains a high percentage of lignin, which is difficult to convert biologically in a relatively short time. Lignin, found most commonly in newsprint, is the organic polymer that holds together the cellulose fibers in trees and certain plants. In most anaerobic conversion processes carbon dioxide and methane constitute over 99 percent of the total gas produced.
Materials most often recovered from MSW include paper, cardboard, plastic, garden trimmings, glass, ferrous metal, aluminum, and other nonferrous metal.
Empty 30 and gallon drums must be metal and open-topped can be recycled at no charge if they've been cleaned and rinsed. Plastic drums are considered garbage. Close top or bung hole drums must fill out an empty container certificate available at the landfill office. Application Forms Please e-mail completed forms to specialwaste wastecom. Forms may be faxed to To download this free program, visit the Adobe Website get.
A field trial was conducted on a silty-loam soil under potato culture in NW Spain, to assess the effect of municipal solid waste MSW compost in a heavily fertilized acid soil. Compost addition at the highest dose decreased bulk density and increased soil porosity and soil stability against water erosion. Compost significantly increased soil microbial biomass and dehydrogenase activity. Due to the high nutrient status in the control soil, potato yield was not increased by compost or inorganic fertilization. A negative consequence of compost addition was the increased extractability of trace metals such as Zn, Cu, Pb and Ni, although their total concentrations in soil or in potato tubers did not increase with respect to the control.
You were introduced to the main types of liquid waste in Study Session 1. This study session is the first of three that builds on that introduction and describes liquid wastes in more detail. We begin with a closer look at the sources and characteristics of liquid wastes. Study Session 5 focuses on the different types of latrine available for urban areas in Ethiopia. In Study Session 6 you will learn about the management and treatment of liquid wastes. The type and composition of liquid waste depends on the source.
Physical. • Chemical. • Biological. Page Physical Characteristics. ➢This includes the determination of percent contents of various ingredients of the solid waste.
The discussion is limited to an analysis of residential, commercial, and some industrial solid wastes. Because the specific weight of MSW is often reported as loose, as found in containers, uncompacted, compacted, and the like, the basis used for the reported values should always be noted. Specific weight data are often needed to assess the total mass and volume of waste that must be managed. Typical specific weights for various wastes as found in containers, compacted, or uncompacted are reported in Table 3.
The Environmental Protection Agency EPA defines solid waste as any garbage or refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, including solid, liquid, semi-solid, or contained gaseous material resulting from industrial, commercial, mining, and agricultural operations, and from community activities. There are two primary types of solid waste -— municipal solid waste trash or garbage and industrial waste a wide variety of non-hazardous materials resulting from the production of goods and products. Conversely, hazardous waste is waste that is dangerous or potentially harmful to our health or the environment. Hazardous wastes can be liquids, solids, gases, sludges, discarded commercial products e. Under Texas regulations, non-hazardous wastes are categorized as Class 1, Class 2 and Class 3. Class 2 and Class 3 waste are considered less harmful to the environment or human health than Class 1 waste. Class 1 wastes are wastes which are regulated by the TCEQ and are potentially threatening to human health and the environment if not properly managed, because of the constituents and properties this class can include.
Увидев эту цифру, Бринкерхофф испытал настоящий шок. 999 999 999. Он ахнул. Миллиард долларов. Соблазнительный образ Кармен тут же улетучился. Код ценой в один миллиард долларов. Некоторое время он сидел словно парализованный, затем в панике выбежал в коридор.
За дверью послышалось какое-то жужжание, словно кабина была на месте.
За этой дверью находился один из самых великих людей, которых ей довелось знать. Пятидесятишестилетний коммандер Стратмор, заместитель оперативного директора АНБ, был для нее почти как отец. Именно он принимал ее на работу, именно он сделал АНБ для нее родным домом. Когда десять лет назад Сьюзан поступила в агентство, Стратмор возглавлял Отдел развития криптографии, являвшийся тренировочной площадкой для новых криптографов, криптографов мужского пола. Хотя Стратмор терпеть не мог выделять кого-нибудь из подчиненных, он с особым вниманием относился к своей единственной сотруднице. Когда его обвиняли в фаворитизме, он в ответ говорил чистую правду: Сьюзан Флетчер - один из самых способных новых сотрудников, которых он принял на работу. Это заявление не оставляло места обвинениям в сексуальном домогательстве, однако как-то один из старших криптографов по глупости решил проверить справедливость слов шефа.
Тысчонка за сеанс. Бринкерхофф ухмыльнулся. Деньги налогоплательщиков в действии. Когда он начал просматривать отчет и проверять ежедневную СЦР, в голове у него вдруг возник образ Кармен, обмазывающей себя медом и посыпающей сахарной пудрой. Через тридцать секунд с отчетом было покончено. С шифровалкой все в полном порядке - как. Бринкерхофф хотел было уже взять следующий документ, но что-то задержало его внимание.
На каждой - буква алфавита. Сьюзан повернулась к. - Так скажите же мне .
A description of the methods used to determine chemical characteristics of the wastes is in Bareither et al. (b). Bulk waste samples ranging.Reply
solid waste is an important physical property because it governs the movement of liquids & gases in a landfill. resulting from the burning of waste.Reply