固体废物资源化技术

固体废物资源化技术
Recycling Technologies of Solid Waste （Bilingual Teaching）
张文阳
Prof. Dr. Eng.
西南交通大学地球科学与环境工程学院
固体废弃物资源化技术
2011年9月
1. 概论
Introduction
1.1 固体废弃物资源化现状
Status of SW Recycling
1.2循环经济& 零废物目标
Economic cycle and zero waste goals
1.3 固体废弃物资源化的基本原则
Basic principle of SW recyling
1.4 固体废弃物资源化管理和技术体系
Management and technologie system of SW recycling
2. 可资源化固体废物的定义和分类
Definition and Classification of Recyclable SW
2.1 可资源化固体废物的定义
Definition of Recyclable SW
2.2 固体废弃物的来源
Sources of SW
2.3可资源化固体废物的种类
Types of Recyclable SW
2.4可资源化固体废物的组成
Composition of Recyclable SW
2.5 来自分类收集的城市生活垃圾中的可资源化物料
Recyclable Materials Commonly Separated from Recyclable MSW
3. 固体废弃物资源化管理
Management of SW Recycling
3.1 固体废物“3R’s”一体化管理法规
Laws and Regulations of ―3R’s‖ integrated management regulations of SW 3.2 固体废弃物“3R’s”一体化管理体系
―3R’s‖ integrated management system of SW
3.3 发达国家城市生活垃圾资源化财政机制
Financing mechanisms of SW recycling of developed countries
4. 固体废弃物资源化源头分类收集
Source separately collection of SW recycling
4.1 分类收集的城市生活垃圾
MSW of separately collection
4.2 城市生活垃圾分类收集
Separately collection of MSW
5. 分类收集城市生活垃圾的分选技术
Sorting technologies of separately collected MSW
5.1 分选技术的基本方法和设备
Fundamental methode and equipment of sorting technologies
5.2 分类收集城市生活垃圾包装材料分选技术
Processing technologies for separately collected commingled package materials 6. 典型可资源化废弃物处理技术
Treatment technologies of typical recycleble SW
6.1 废玻璃资源化
Glass Recycling
6.2 废金属资源化
Metal Recycling
6.2.1黑色金属（铁和钢）
FERROUS METAL (IRON AND STEEL)
6.2.2 有色金属
NONFERROUS METAL
6.2.3 铝
ALUMINUM
6.3 废纸资源化
Paper Recycling
6.4 废电池资源化
Batteries Recycling
6.4.1 家用电池
Household Batteries
6.4.2 铅酸电池
LADE-ACID BATTERIES 6.5 废塑料资源化
Plastic Recycling
CHAPTER 1
INTRODUCTION
1-1 STATUS OF SW RECYCLING
Solid wastes (SW) comprise all the wastes arising from human and animal activities that are normally solid and that are discarded as useless or unwanted. The term solid waste as used in this text is all-inclusive encompassing the heterogeneous mass of throwaways from the urban community as well as the more homogeneous accumulation of agricultural, industrial, and mineral wastes. The solid waste management is focused on the urban setting, where the accumulation of solid waste is a direct consequence of life.
SOLID WASTE-A CONSEQUENCE OF LIFE
From the days of primitive society, humans and animals have used the resources of the earth to support life and to dispose of wastes. In early time, the disposal of human and other wastes did not pose a significant problem, for the population was small and the amount of land available for the assimilation of wastes was large Although emphasis is currently being placed on recycling the energy and fertilizer values of solid wastes, the farmer in ancient times probably made a bolder attempt at this. Indications of recycling may still be seen in the primitive, yet sensible, agricultural practices in many of the developing nations where farmers recycle solid wastes for fuel or fertilizer values.
Problems with the disposal of wastes can be traced from the time when humans first began to congregate in tribes, villages, and communities and the accumulation of wastes became a consequence of life. Littering of food and other solid wastes in medieval towns-the practice of throwing wastes into the unpaved streets, roadways, and vacant land-led to the breeding of rats. With their attendant fleas carrying bubonic plague. The lack of any plan for the management of solid wastes thus led to the epidemic of plague, the Black Death that killed half of the fourteenth-century Europeans and caused many subsequent epidemics with high death tolls. It was not until the nineteenth century that public health control measures became a vital consideration to public officials, who began to realize that food wastes had to be collected and disposed of in a sanitary manner to control rodents and flies, the vectors or disease.
The relationship between public health and the improper storage, collection, and disposal of solid wastes is quite clear. Public heath authorities have shown that rats, flies, and other disease vectors breed in open dumps, as well as in poorly constructed or poorly maintained housing, in food storage facilities, and in many other places where food and harborage are available for rats and the insects associated with them.
Ecological phenomena such as water and air pollution have also been attributed to improper management of solid wastes. For instance, liquid from dumps and poorly engineered landfills has contaminated surface waters and ground-waters. In mining areas the liquid leached from waste dumps may contain toxic elements, such as copper, arsenic, and uranium, or it may contaminate water supplies with unwanted salts of calcium and magnesium. Although nature has the capacity to disperse, degrade, absorb, or otherwise reduce the impact of unwanted residues in the atmosphere, in the waterways, and on the land, ecological imbalances have occurred where the
natural assimilative capacity has been exceeded.
WASTE GENERATION IN A TECHNOLOGICAL SOCIETY
The development of a technological society can be traced to the beginnings of the Industrial Revolution in Europe; unfortunately, so can a major increase in solid waste disposal problems. In fact, in the latter part of the nineteenth century, conditions were so bad in England that an urban sanitary act was passed in 1888 prohibiting the throwing of solid wastes into ditches, rivers and waters. This preceded by about 11 years the enactment of the Rivers and Harbors Act of 1899 in the United States, which was intended to regulate the dumping of debris in navigable waters. and adjacent lands.
Thus, along with the benefits of technology have also come the problems associated with the disposal of the resultant wastes. To understand the nature of these problems, it will be helpful to examine the flow of materials and the associated generation of wastes in a technological society and to consider the direct impact of technological advances on the design of solid waste facilities.
Fig. 1-1 Materials Flow and Waste Generation
An indication of how and where solid wastes are generated in our technological society is shown in the simplified materials flow diagram presented in Fig. 1-1. Solid wastes (debris) are generated at the start of the process, beginning with the mining of raw materials. The debris left from strip-mining operations, for example, is well known to everyone. Thereafter, solid wastes are generated at every step in the process as raw materials are converted to goods for consumption.
The Effects of Technological Advances
Modem technological advances in the packaging of goods create a constantly changing set
of parameters for the designer of solid waste facilities. Of particular significance are the increasing use of plastics and the use of frozen foods, which reduce the quantities of food wastes in the home but increase the quantities at agricultural processing plants. The use of packaged meals, for example, results in almost no wastes in the home except for the packaging materials. These continuing changes present problems to the facilities designer because engineering structures for the processing of solid wastes involves such large capital expenditures that they must be designed to be functional for approximately 25 years. Thus, the engineers responsible for the design of solid waste facilities must be aware of trends, even though the3, cannot, of course, predict all the changes in technology that will affect the characteristics of solid wastes.
THE CURRENT SITUATION OF SOLID W ASTE MANAGEMENT IN
CHINA
Chinese recent GDP growth has been maintained at around 8% (NBSC, 2010). A series of GDP figures also means a series of problems behind. In China, there are a large number of carbon-intensive manufacturing. Behind the rapid growth of GDP, there are a large number of factories were established. While the large number of factories means the inevitable expansion of the scale of cities. With the rapid development of modern urban construction, urban population and the people‘s consumption are also gowned. However, in the meantime, it also creates a growing number of municipal solid waste (MSW). Although the MSW disposal problem is one of the problems in most of the countries at present, the situation in developing countries are more serious.
China’s economy ran at a double‐digit growth rate (as measured by the percentage increase in gross domestic product) from 2003 to 2008 when the global financial crisis hit, and the country came out strongly from the crisis (ADB, 2010). In parallel to this impressive growth, total primary energy consumption increased from 776 million tonnes of oil equivalent (Mtoe) in 2000 to 2 164 Mtoe in 2009, reflecting a compound annual growth rate in excess of 8% (NBS, 2010).
In the same period, electricity consumption rose to 3 643 terawatt hours (TWh) in 2009, up 6% compared to 2008 and increasing by a factor of 3.4 times since 2000 (CEC, 2010). The IEA estimates that China‘s electricity demand wi ll almost triple to 9 594 TWh by 2035, with an average growth rate of 5.3% (Figure ) (IEA, 2010a).
Fuel and mineral imports from the world have shown the most important increases since 2000 and have maintained their share at 35% and 43% respectively; agriculture, imports have increased at a lower scale resulting in a 10% decrease in its share to 26%.
However, along with urbanization, population growth and industrialization, the quantity of municipal solid waste (MSW) generation has been increasing rapidly. in the meantime, it also creates a growing number of municipal solid waste (MSW). Although the MSW disposal problem is one of the problems in most of the countries at present, the situation in developing countries are more serious.
Fig. 1-2 Increasing quantity of municipal solid waste (MSW) generation
In China, along with urbanization, population growth and industrialization, the quantity of municipal solid waste (MSW) generation has been increasing rapidly. The total MSW amount increased from 31.3 million tonnes in 1980 to 156 million tonnes in 2005.
Fig. 1-3 Variation of quantity of MSW (collected and transported) and the
disposal rate
In 2002, the quantity of MSW disposed of was 74.04 million tons, which was 54.2% of the total quantity of MSW collected and transported. The rest was dumped at appointed sites of the 74.04 million tons of MSW disposed of, 89.30% was landfilled, 3.72% was incinerated, and 6.98% was composted.
Many cities have no modern MSW landfill sites because of poor economic conditions, but the MSW produced has to be disposed of every day, so the MSW is dumped at some selected sites. If MSW is dumped at a site appointed by local government, it is called ―dumping at an appointed site‖ and is legal. If M SW is dumped at a site not appointed by the local government, it is called ―discharging‖ and is illegal.
1-2 ECONOMIC CYCLE AND ZERO WASTE
ECONOMIC CYCLE
Circular economy is a model of economic development which aims at environmental protection, pollution prevention and sustainable development through conservation of resources, reusing, and recycling in order to minimize pollution from the source and reduce overall waste per unit output.
The government should be aware of the following four points:
1 The reuse and recycling of resources and waste promotes an efficient use of existing resources.
2 Protection of the environment and prevention of pollution are the foremost aims of developing a circular economy. However, such aims often cannot be achieved through a traditional market because polluters and beneficiaries do not necessarily have to pay for the damages they cause or benefits they receive (the so-called economics of externality); thus government intervention is required. On the other hand, the government should still make maximum use of economic means and market mechanisms and should incorporate environmental factors into the economic system. Only when absolutely necessary should the government use administrative measures to intervene in the market.
3 Circular economy transforms traditional patterns of economic growth. Circular economy not only targets waste disposal, it also involves transformation of industrial organization and allocation, urban infrastructure, environmental protection, technological paradigms, social welfare distribution, etc. These transformations are based on systemwide innovations for the whole economy. Therefore developing circular economy shall take a system innovation approach as the first step. Furthermore, the government should play a key role in mobilizing society as a whole to establish a new culture of circular economy.
4 To establish a new economic development pattern means either upgrading or replacing the existing production pattern. The new circular economy model can obtain the benefits of environmental protection without compromising rapid economic growth, but the government must realize that certain policies necessary for developing circular economy may lead to rising prices of certain inputs, especially for primary resources, and may reduce the economic growth rate measured by the traditional GDP.
BASIC PRINCPLE OF ECONOMIC CYCLE -- 3R’s
Waste minimisation aims to eliminate waste before it is produced and reduce its quantity. Prevention is the primary goal, followed by reuse, recycling, treatment and appropriate disposal. Reuse: using things again and again by, for example, refilling drinks bottles and re-using envelopes.
Reduce: avoiding the creation of so much waste in the first place, by not buying things wrapped in lots packaging.
Recycle: the reprocessing of specific materials into other materials or products.
CIRCULAR ECONOMIC AT THREE LEVEL
At the level of enterprise, circular economy mainly focuses on cleaner production, comprehensive waste recycling and recovery, and non-hazardous waste disposal. It emphasizes ―reduce, reuse, and recycle‖ for materials and energy.
At the regional level, circular economy emphasizes structuring a substance recycling network which takes the industrial chain as the carrier in order to realize optimum regional resource allocation and reuse through the establishment of an industrial system for comprehensive waste collection, reproduction, recycling and non-hazardous disposal.
At the national level, circular economy represents a new pattern of economic operation, which, assisted by government participation, aims at sustainable economic and social development. This pattern brings waste and environmental elements into the market system, utilises market mechanisms to regulate with laws, regulations, and policies, and follows principles of resource conservation and environmental consciousness.
CIRCULAR ECONOMIC IN PRACTICE
As discussed above, there are many factors that affect what should be considered a practice in a particular situation. Decision makers need to assess how the specific, prevailing background conditions constrain the choices available. It is unlikely that all of the following points will be important in any one instance, but the list of conditions that help to determine what is practice of economic cycle includes:
Level of development
•economic development, including relative cost of capital, labor, and other resources; •technological development; and
•human resource development, in the MSW field and in the society as a whole
Natural conditions
•physical conditions, such as topography, soil characteristics, and type and proximity of bodies of water;
•climate temperature, rainfall, propensity for thermal inversions, and winds; and
•specific environmental sensitivities of a region.
Conditions primarily affected by human activities
•waste characteristics density, moisture content, combustibility, recyclability, and inclusion of hazardous waste in MSW; and city characteristics size, population density, and infrastructure development.
Social and political considerations
•degree to which decisions are constrained by political considerations, and the nature of those constraints;
•degree of importance assigned to community involvement (including that of women and the poor) in carrying out MSWM activities; and
•social and cultural practices.
ZERO WASTE (ZW)
Zero Waste – What is it?
In natural systems, waste does not exist. All waste materials generated by organisms at one level are input or food for organisms at a different level. This fact leads to the important realization: in our life systems, waste represents misplaced resources, and an important aspect of Zero Waste is the need for a shift in attitude, from waste as a problem to waste as a resource.
The Zero Waste starts and ends with Nature itself and the world we live in, which is a whole-system approach to addressing the problem of society‘s unsustainable resource flows. Over time Nature has devised a system where waste from one organism becomes resources for others, creating cyclical material flows in a state of constant equilibrium and balance. Highly sensitive feedback systems ensure that whenever wastes (used resources) begin to accumulate, the
opportunities to utilise them are quickly taken up by other organisms to build more abundance and common wealth. It has taken Nature hundreds of millions of years to perfect Zero Waste and it is a fundamental principle of the natural world.
Zero Waste is a design principle and planning approach for the environmental management of resources.
In short – a ZW strategy ensures that the supplies used, the products sourced and ultimately sold, and packaging are carefully designed or specified:
•to reduce the total amount of material needed,
•to be used for as long as possible and to provide opportunities for re-use, and
•to be easily and economically recycled when useful product life is complete.
In long - a Zero Waste goal will ensure energy, water, and material flows are operating as efficiently as possible. It will ensure fewer resources are used to deliver comparable or better products and services. In adopting Zero Waste, businesses become more sustainable themselves by reducing costs, while reducing the demands their operations place on the environment.
Zero Waste aims to:
•Redesigns the current, one-way SW system into a cyclical system modelled on Nature‘s successful strategies.
•Helps communities develop local economies, sustain good jobs, and provide a measure of selfsufficiency.
•Reduces consumption and ensures that products are made to be reused, repaired or recycled back into nature or the marketplace.
•Is a powerful new concept that enables us to challenge old ways of thinking and inspires new attitudes and behaviour - the hallmarks of a breakthrough strategy.
•Is a competing waste disposal option to landfilling (and incineration) and is consistently showing to be a more economically viable option.
·Protecting public health and the environment from pollution and greenhouse gas production. ·Conserving raw materials and energy in the production, transportation, and disposal of goods. ·Reducing overconsumption by encouraging the consumer to eliminate the purchase of unnecessary goods and packaging, especially single use, disposable items.
·Facilitating community economic development and local jobs in repair, refurbishing and recycling.
·Internalizing environmental and social costs in the prices of products and services. ·Encouraging ―Cradle to cradle‖ design and management systems that cycle a ll materials safely back into the environment or the marketplace.
1-3BASIC PRINCIPLE OF SW RECYCLING
About 3R’s: Waste Reuse, Reduce and Recycle
The ―circular economy‖ as mentioned in above is a generic term for the reducing, reusing and recycling activities conducted in the process of production, circulation and consumption. Waste minimisation aims Similarly to eliminate waste before it is produced and reduce its quantity. Prevention is the primary goal, followed by reuse, recycling, treatment and appropriate disposal. Reuse:using things again and again by, for example, refilling drinks bottles and re-using envelopes.
Reduce: avoiding the creation of so much waste in the first place, by not buying things wrapped in lots packaging.
Recycle: the reprocessing of specific materials into other materials or products.
The basic principle of SW recycling is based on the three target areas of avoidance and minimisation; reuse, recovery and recycling; and bulk reduction and disposal.Within each target area is a series of proposed initiatives, each a goal in itself that in turn contributes to the achievement of the main target.
The waste hierarchy is a list of approaches to managing waste, arranged in order of preferability. The waste hierarchy is widely used as a simple communication tool for waste managment, which is the strategies to aviod products becomming waste and seek to find a use for waste (J Gertsakis and H lewis, 2003). In this thesis, we are going to use the waste hierarchy to analyze the China‘s MSW managment and compare with the Danish waste treatment model, to improve the waste mangement system in China base on the waste hierarchy.
From Fig. 1-4, we can see that the present China‘s waste hierarchy has problems for each aspect, such as landfill is the least priority in the waste hierarchy, but in Chinese present situation, landfill
occupied more than 80% for waste disposal (China Statistical Yearbook, 2009). However, in Denmark, landfill only occupied a little—9%( Henrik Wejdling, 2008), because most of the waste is reused and recycled. Therefore, the sollutions to improve China‘s waste management system is to change ‖China‘s triangle‖ into ‖Danish triangle‖, which means to lower the landfill proportion and increase the proportion of waste reduce, reuse, and recycling (3R).
Fig. 1-4 Differences Between the China‘s Waste Hierarchy and Danish Waste Hierarchy
1-4MANAGEMENT AND TECHNOLOGIES SYSTEMS OF SW RECYCLING Management and technologies system of SW recycling is a leading provider of services and products for solid waste processing systems and recycling facilities. The system provides innovative processing system solutions that result in maximum performance for 3R’s. The following categories are typical management and technologies system about SW recycling:
1. Management system and financial Systen of MSW Recycling
2.Source separately collection for SW recycling
3.Sorting technologies of separately collected MSW
4. Treatment technologies of typical recycleble SW
5. Recycling technologies of municipal bio-waste
6. Thermal treatment technologies (incineration) of MSW
7. Disposal of Residuals for MSW recycling
CHAPTER 4
SOURCE SEPARATELY COLLECTION OF SW RECYCLING
4-1 MSW OF SEPARATELY COLLECTION
Separation for Recycling
The separation of solid waste components at the source of generation is one of the most positive and effective ways to achieve the recovery and reprocess of materials. Once the waste component is separated ,the question facing the homeowner is what to do with the wastes until they are collected or taken to a local buy-back or recycling center.
Why Source Separate?
In Morris County Solid Waste Management Plan requires "source separation" to be the primary method of separating the recyclable waste stream from the solid waste stream for the following reasons:
•Source separation is mandated by law under the country. In support of this law the community favors a consistent source separation policy throughout the residential, commercial and institutional sectors.
•Source separation promotes the removal of all designated recyclable materials from the waste stream and, therefore, helps in achieving high reduction rates.
•Source Separation promotes clean, marketable materials by limiting levels of contamination. Contamination undermines long-term marketability of recyclable materials.
•Source Separation enables the recycler at the source to receive the economic benefits of cost avoidance by not disposing of recyclable materials as solid waste as well as enabling the recycler to receive revenue by the sale of the recyclable material.
•Source separation fosters a free market, independent of the solid waste collection and disposal system. This reduces the need for burdensome regulations and costly enforcement. •Proper documentation is difficult, if not impossible, when recyclables are mixed with solid waste.
•Source separation fosters competition among recycling companies, thereby keeping costs low and quality of services high.
•Source separation encourages a thought process among each individual recycler that solid
waste disposal is every person's responsibility. This can foster further source reduction and recycling activities at work, home and school.
The success of recovery and recycling depends on the separation of waste at source. There is a distinction between 'clean' sorted waste (like paper, plastics, and metals) and 'dirty' waste (contaminated materials, such as food packaging, used tissues and soiled diapers). Dirty waste is commonly known as mixed waste and has little recycling value. On the other hand, clean sorted waste holds high value for the recycling industry.
Waste separation is considered in the greater detail in the following two types:
(1) At Detached Dwellings
The residents or tenants of detached dwellings are responsible for placing the solid wastes and recyclable materials that are generated and accumulated in and around their dwellings in storage containers. The types of storage containers used to depend on whether waste separation is mandated. In many communities, the decision has been made to reach the mandated separation goals using materials recovery facilities (MRFs). In some collection systems, mixed wastes are placed in a variety of storage container with little or no standardization.
(2) At Apartment Buildings
Handling methods in most apartment buildings resemble those used for dwellings, but methods may vary somewhat depending on the waste storage locations and collection method. Typical solid waste storage location include basement storage, outdoors storage, and, occasionally, compactor storage.
In the apartment buildings the most common methods of handling solid wastes involve one or more of the following:
i wastes are picked up by building maintenance personnel or porters from the various floors and taken to the basement or service area;
ii wastes are taken to the basement or service area by tenants; or
iii wastes, usually bagged, are placed by the tenants in specially designed vertical chutes (usually circular) with openings located on each floor. Wastes discharged in chutes are collected in large containers, compacted into large containers, or baled directly.
Recyclable materials may be put outside in the hall or entry way for pickup. Or they may be taken by the tenants to the service area located on each floor for pickup. Bulky items are usually taken to the service area by the tenants or the building maintenance crew. In many apartments, solid waste chutes are used in conjunction with large compactors. The building maintenance personnel are responsible for handling the compressed wastes and any other waste or recyclable materials that tenants bring to the service areas.
4-2 SEPARATELY COLLECTION OF MSW
Collection Systems
Waste materials that have been separated at the source must be collected or gathered together before they can be recycled. The principal methods now used for the collection of these materials include curbside collection using conventional and specially designed collection vehicles, incidental curbside collection by charitable organizations, and delivery by homeowners to drop-off and buy-back centers.
The effectiveness of residential waste separation programs depends on the type of system used for the collection of separated wastes. A number of communities use a collection system in which three containers used for recycled materials in addition to one or more containers for non-recyclable materials. In the three-containers system, newspaper is placed in one container. Aluminum cans, glass, and plastics are placed in the second container. The remaining wastes are placed in the third container. The separated materials, placed in special containers, are collected at the curb.
Curbside Collection
(1) The separated wastes are placed in special containers or bags. In system in which the waste components are separated, the solid wastes remaining after the recyclable materials have been separated are placed in one or more large container.
(2) In some residences, waste compactors are being used to reduce the volume of wastes to be collected. Compacted wastes are usually placed in waste container or in sealed plastic bags. (3) The homeowner or tenants are responsible for transporting the containers equipped with wheels for the recyclable materials and residual waste to the street curb for collection systems.。