Urban solid waste management in Chongqing: Challenges and opportunities

www.elsevier.com/locate/wasman

Waste Management 26 (2006) 1052–1062

Country report

Urban solid waste management in Chongqing: Challengesand opportunities

Yuan Hui a,*, Wang Li�ao a,b, Su Fenwei a,b, Hu Gang a

a Department of Resource and Environmental Science, Chongqing University, Chongqing 400044, Chinab Key Lab for the Exploitation of Southwestern Resource and the Environmental Disaster Control Engineering, Ministry of Education China,

Chongqing University, Chongqing, China

Accepted 15 September 2005Available online 8 November 2005

Abstract

The dual influences of the resource supply and protection in ecological environments will pose a significant challenge to China�s sus-tainable development. Solid waste management offers opportunities to improve profits by conserving resources and improving environ-mental performance. This paper examines municipal solid waste (MSW) management in urban Chongqing, the nation�s fourth largestmunicipality after Beijing, Shanghai and Tianjin. In this paper, we will provide information on the quantity and composition of MSW, aswell as give an overview of different methods for collection, transport, treatment and disposal of MSW. At present the daily amount ofMSW generated per person is about 1.08 kg; food waste accounts for about 59% of total MSW. MSW in Chongqing has a higher mois-ture content (64.1%) and a lower LHV (3728 kJ/kg) than other cities in Asia, which is an obstruction for incineration. Landfills are themain method of disposal in Chongqing, but pollution caused by simple landfills and lack of backup MSW disposal capacity are becomingmajor problems in the main districts of Chongqing. In this paper, the challenges being faced and opportunities to MSW in Chongqing areanalyzed and some suggestions are given for improving the MSW system in the future.� 2005 Elsevier Ltd. All rights reserved.

1. Introduction

In the past 20 years, the Chinese economy has achievedfaster growth, but ecological damage and environmentalpollution have also increased at a high rate. The govern-ment, and national and foreign experts, agree that the dualinfluences of resource supply and protection of ecologicalenvironments will pose a significant challenge to China�ssustainable development (Qi, 2004; Su and Wang, 2003).

Since China already produces 29% of the world�s MSWeach year (Dong et al., 2001), an integrated solid wastemanagement (ISWM) system that includes the reducing,reusing, recycling and disposal of waste material will playan important role in China�s sustainable development dueto its several benefits: (i) reducing the depletion of theearth�s limited natural resources; (ii) reducing pollution

0956-053X/$ - see front matter � 2005 Elsevier Ltd. All rights reserved.

doi:10.1016/j.wasman.2005.09.005

* Corresponding author. Tel./fax: +86 23 65111477.E-mail address: [email protected] (H. Yuan).

produced by discharging untreated waste; (iii) indirectlysaving energy. At present, ISWM is considered to be anoptimized waste management system where the environ-mentally and economically best solution is chosen for eachcase, without regard to the waste hierarchy (Sundeqvist,1999), and to be the key towards successful MSW treat-ment (Hu et al., 1998). The implementation of the ISWMsystem, however, depends on several important factorssuch as the country statutes, environmental requirements,the strategies in environmental management, energy policy,economic and technological feasibility, and the educationand environmental awareness of the Chinese people.

Some advanced industrial countries, such as Germany,Sweden, Japan, and the United States have achievedremarkable results in resource comprehensive utilizationand solid waste management. As shown in Fig. 1, therehave been a lot of changes in the strategies of solid wastemanagement in these countries during the period of1960–2004. One revolutionary change was that the solid

mailto:[email protected]

1975~1990 1990~2004 1960~1975 Classification Reduction Landfilling

ISWM Recycling Landfills

AvoidanceAvoid

Reduction Recycling Composting Reduction

Recycling Recycling

Recovery Incineration LandfillsRecovery

Land. Landfills

Fig. 1. Solid waste management – revolutionary changes in the strategies in the advanced industrial countries during the period 1960–2004.

H.Yuan et al. / Waste Management 26 (2006) 1052–1062 1053

waste management begins with reduction – using less tobegin with and reusing more – and recycling. In addition,incinerating and composting organic waste became domi-nant methods of solid waste treatment instead of disposalby landfills.

Currently there are about 660 cities in China that pro-duce an annual quantity of about 130 Mt of solid waste.In general, China still has a bigger gap in solid waste recy-cling, treatment technology, and management strategycompared with many advanced countries. Throughoutthe country, solid waste management is becoming a majorissue. The treatment and disposal of urban solid waste willbe an important goal for the governments of all cities in theyears to come. In this area, the potential for developmentand business opportunities are enormous in China.

Chongqing, located in southwest of China, is thenation�s fourth largest municipality after Beijing, Shanghai,and Tianjin. It is also the economic center and the hub ofall transportation (water, land, and air) in and out ofsouthwestern China with busy rivers and highways radiat-ing in all directions. Because of its location at the head ofthe very large reservoir behind the Three Gorges Dam,Chongqing is slated to become the beachhead for the devel-opment of western China.

Chongqing Municipality has 40 districts and countieswith an area of about 82,000 km2, and population of about31 million people. The main urban area of ChongqingMunicipality, often called Chongqing, consists of nine dis-tricts (Dadukou, Yuzhong, Jiangbei, Shapingba, Jiu-longpo, Nan�an, Beibei, Ba�nan, and Yubei) and is thecenter of the Chongqing Municipality in finance, educationand culture. These main districts are between YangtzeRiver and Jialing River. In the past, most of the MSWwas piled along the riversides, dumped directly into theriver or just minimally treated. The secondary pollutioncaused by the MSW was harmful to the sanitation andenvironment. For example, during heavy rains leachatewould run off into the Yangtze and Jialing rivers. Now,as the completion of the Three Gorges Reservoir nears,both the rivers� flow rates and their carrying capacity ofthe pollutants will change; both MSW management and

disposal in Chongqing Municipality are becoming vital tothe environmental protection of the Reservoir area.

In this paper, Chongqing�s urban solid waste manage-ment is introduced in detail with regard to the area�s solidwaste characteristics, management, collection system,treatment processes and the disposal methods. The majorproblems faced at the main districts in the ChongqingMunicipality will also be analyzed. Our analysis explainsthe future challenges and opportunities for improving thesolid waste management system.

2. Generation and characteristics of the urban solid wastes

The amount of MSW generated in the main districts ofChongqing has increased with the growth of the economyand urban population. In 1996, the total amount of theMSW was 0.888 million tons, the average amount gener-ated per day equaled 3072 tons and the daily amount gen-erated per person was 0.95 kg (Li and Gu, 2001). In 2001,the annual total and average amount generated per dayrose to about 1.16 million tons and 3176 tons, respectively,which means the daily amount generated per person rose tonearly 1.08 kg. As shown in Fig. 2, urban solid waste(USW), is mainly composed of domestic refuse, road clean-ing refuse and institutional refuse (official, business,schools, and service industries), as well as a small amountof construction refuse.

Table 1 shows the composition of USW in the main dis-tricts of Chongqing Municipality. It is clear that the concen-tration of food waste in urban solid waste makes up thehighest proportion at 59.2% followed by plastics, paper,fiber, wood, glass, metal, and rubber. The metal content ofsolid waste generated in Shapingba district is higher thanin the two other sites. The characteristics of USW composi-tion at the main districts in Chongqing are shown in Table 2.Compared with the results of an investigation in 1998 (Li andGu, 2001), specific weight, combustibles and ash contentdata in 2002 declined significantly, while the percentage offiber and paper has increased over the years.

It can be seen from Fig. 3 that the composition andproperties of the USW generated in Chongqing are

Table 1Composition of urban solid waste in Chongqing�s main districts (%)

Location Paper Fiber Plastic Rubber Wood Food waste Metal Glass

Longtousi pilling site 10.0 6.1 18.3 0.4 4.4 58.5 0.1 2.2Xinglong pilling site 9.6 6.6 15.2 0.0 5.1 57.8 0.7 4.9Shapingba district 10.6 5.5 13.5 0.4 3.0 61.4 2.4 3.2Average 10.1 6.1 15.7 0.3 4.2 59.2 1.1 3.4

Table 2Characteristics of urban solid waste at the main districts in Chongqing(1998 and 2002)

Characteristics 1998 (Li and Gu, 2001) 2002

Food waste percentage (%) 69.3 59.2Paper and fiber percentage (%) 6.5 16.2Specific weight (kg/m3) 470 351Combustibles (%) 37.1 22.8Ash content (%) 16.31 13.1Moisture content (%) 53.6 64.1Net calorific value (kJ/kg) – 3728

Fig. 2. Urban solid waste composition in Chongqing.

1054 H. Yuan et al. / Waste Management 26 (2006) 1052–1062

different from two other Asian cities, Kitakyushu, Japan(Kitakyushu Environmental Cooperation Center) and Sin-gapore City, Singapore (Bai and Sutanto, 2002), due to dif-ferences in economic development and standards of living.

Fig. 3. Comparison be

Compared with these two cites, the concentration of foodswaste and the moisture content of the urban solid waste inChongqing are much higher while the net caloric value ismuch lower. The net caloric value of the solid waste gener-ated in Kitakyushu and Singapore is about 9630 and8000 kJ/kg, respectively, but the net caloric value of thesolid waste in Chongqing is only about 3728 kJ/kg.Although it meets the lowest caloric value needed for incin-eration, it is far too low for waste heat utilization and cost-effective incineration.

Tchobanoglus et al. (1993) propose the following typicaldistribution of components in residential MSW for low-(per capita income less than US$750, 1990), middle- (percapita income US$750–5000) and upper-income (per capitaincome more than US$ 5000) countries (see Table 3).

tween three cities.

Table 3Comparison of typical distribution of components between Chongqing and low-, middle- and upper-income countries

Component Chongqing(average)

Typical distribution of components in residential MSW (Tchobanoglus et al., 1993)

Low-incomecountries

Middle-incomecountries

Upper-incomecountries

Food waste 59.2 40–85 20–65 6–30Paper 10.1 1–10 8–30 25–60Plastics 15.7 1–5 2–6 2–8Textiles, fiber 6.1 1–5 2–10 2–6Rubber, leather 0.3 1–5 1–4 0–4Yard waste, wood 4.2 1–5 1–10 11–24Glass 3.4 1–10 1–10 4–12Metal 1.1 1–5 1–5 3–13


According to Table 3, Chongqing belongs to the statusbetween low- and middle-income levels. Also, accordingto a MSW overview of Asia (Hunsicker et al., 1996), theMSW generation (per person per day) in Chongqing in2001 was lower than that of the average MSW generationlevel (1.95 kg/person/day) of Japan in 1990s. Developedcountries such as Japan and the US have a relatively highMSW generation rate per person per day, therefore thechanges of the MSW generation and properties of USWin Chongqing show that Chongqing�s standard of livinghas improved and the fuel structure has changed from pre-dominantly coal use to natural gas. This increase of dailyMSW generation per person with increased economicdevelopment and standard of living also occurs in other cit-ies in China such as Guangzhou (Chung and Poon, 1998a),but Chinese people have a habit of preferring food that isunprocessed and unpackaged. The result of this preferencemay mean that the proportion of MSW that is made up offood waste will not decline significantly even as industry

Fig. 4. Urban solid waste

grows and wealth increases. Even in the more developedChinese cities such Guangzhou and Hong Kong, foodwaste is higher when compared to most western countries(Chung and Poon, 1998a).

3. Urban solid waste management

Under the national laws and regulations of solid wastemanagement, treatment and disposal, there are local regu-lations and laws related to USW management, such as‘‘Chongqing Municipal Solid Waste Disposal Fees LevyingRules’’ and ‘‘Municipal Solid Waste Management Rules.’’A representative diagram regarding the solid waste man-agement systems is given in Fig. 4. Chongqing�s solid wastemanagement administration consists of two main institu-tions: the Chongqing Environment Protection Bureau(CEPB) regulates the management of industrial solid waste,while a department under the Chongqing Municipal Admin-istration Commission (CMAC) takes the responsibility for

treatment itinerary.


the management of the MSW. As shown in Fig. 4, the solidwaste management system includes mainly collection sites,transfer stations, recycling and final disposal.

As MSW rapidly grew, the Chongqing Solid WasteDisposal Company (CSWDC) was founded under themanagement of CMAC. CSWDC�s work covered thedesign, construction and management of the solid wastedisposal facilities and landfills. Before the reforms ofthe separating the government from enterprise manage-ment, the Chongqing Solid Waste Company was an eco-nomic unit of the CMAC that was, in turn, anadministrative department of the local government. Afterthe reforms had taken place and in order to enhance thetreatment level of Chongqing, the CSWDC separatedfrom the CMAC, and a state-owned company financedby a local authority, the Environmental and SanitaryProtection Holding Groups (ESPHG) was founded. TheESPHG has been authorized to manage the state�s prop-erties as well as licensed to operate the cleaning, transfer-ring and disposing of urban solid waste through variousfacilities in the main districts of Chongqing Municipality.As a result of market economic principles, the Chongq-ing Solid Waste Disposal Company (CSWDC) has nowbecome a sub-company of ESPHG.

3.1. Collection system

Source-separated collection of household-generatedMSW is one of the key steps for integrated solid wastemanagement (ISWM). Source-separated collection meansthat the MSW is first classified as several different partssuch as composting material (food waste), combustiblematerials (fiber and paper) and recyclable materials(metals and glass). Once classified, these different wastetypes are then collected and forwarded to the appropri-ate users. Unfortunately, source-separated collection atthe household level has not yet been implementedsuccessfully in Chongqing. At present, the maincollection systems of the MSW (as shown in Fig. 5)are as follows:

By residents or

residential village management comp

Residential refuse Collection si

By CMAC

Transfer statiRefuse container

(Separating recycla

By CMAC

Disposal sitRoad cleaning refuse

Fig. 5. Urban solid waste collection sy

(1) Residential refuse: individual households place theirdaily refuse into a container nearby, then the refuseis collected and delivered to the waste collection sta-tion by the residents� committee or the realty manage-ment department of each individual village. TheEnvironmental Sanitary Protection Division of theChongqing Municipal Administration Commission(CMAC) then transfers this refuse to treatment sites.In some large residential villages, the refuse is col-lected and sent directly to the treatment sites by thereal estate company.

(2) Institutional refuse: the collection and transportationof institutional refuse are the responsibility of theindividual institutions or professional environmentand protection companies. (These are paid services.)

(3) Commercial refuse: at most food markets in Chongq-ing, fresh vegetables are often delivered from localfarms and therefore offered directly to the consumerwith very little packaging. Because of this directsource, the refuse always contains a high proportionof organic matter. Except for some unwanted vegeta-bles that are reused as forage to feed animals in thefarms, most refuse is collected by the food market�smanagement office and is sent to the treatment sitesdirectly.

(4) Road and public places cleaning refuse: the cleaningof roads, public places and disposal of this refuse isthe responsibility of a department under the CMAC.The cleaning refuse is first collected into a nearbycontainer, and then it is sent to treatment sites by col-lection vehicles.

(5) Construction refuse: the materials that are unable tobe either recycled or reused are sent directly by theconstruction company to the treatment sites fordisposal.

In some large residential villages, residents are requiredto sort their waste before setting out their waste in bags tobe collected. In 2002, the rate of waste packaging was 68%(CEPB, 2002) and the waste containers on the streets were

anies

Institutional refuse tes (two situations)

By each institution

ons Commercial refuse

ble thing) (two situations)

By each market et al.

es

stem in Chongqing main districts.


not suitable for waste classification. However since 2002,the government has made some attempts to encourage res-idents to classify their waste. In some areas of Chongqing,for example, Shapingba district, the waste containers werere-designed. Local authorities changed the one-box wastereceptacle into a container with two boxes, one for recycla-ble waste and the other for non-recyclable waste (distin-guished by different colors of the containers as well as alabel). In addition, a special box for battery disposal wasset between the two containers.

At present, USW is collected in a mixed state, butresidents can volunteer to participate in the source-separated collection. For residential areas, there are twotypes of urban solid waste collection: collection at roadsidesand household collection. Roadside waste collection is amethod where residents sort recyclable items into the spe-cific collection containers offered by the local authorities.Although many households collect the relatively high valu-able things from the domestic wastes before they place theminto the collection sites, most reusable and recyclable itemsare sent to collection/transfer stations or treatment sites. Asin many cities in developing countries, most reusable thingsare recovered through the discharging process by scaveng-ing from nearby counties that have reusable waste collec-tion system. However, when the scavengers sort throughand remove the reusable items from the waste collectioncontainers or stations, they also often scatter about theremaining unwanted waste on the street. This litter causessanitation problems and is an additional environmentalissue. In addition, workers sorting through the refuse intransfer stations or treatment stations may come into con-tact with physically and chemically unsafe waste products.As a result, these workers are at risk for injury and illness;prolonged contact in this occupation could cause personalhealth and hygiene problems among the operators.

The result of an investigation conducted by ChongqingUniversity in 2002 shows that most of the residents inChongqing were aware of the pre-collection sorting refusecontainers and understood how to use them. Only 21%(Liu, 2003) of all the citizens interviewed disapproved ofthis refuse sorting system. Therefore, there is a strong trendin support of separated refuse collection, which will behelpful to future waste recycling and reuse.

3.2. Transfer station

In Chongqing, the transfer station is a small two-storeybuilding that is used to facilitate the transfer of urban solidwaste from smaller collection vehicles to large transportvehicles. All of them are storage-load transfer stations orplaces where USW is emptied directly into the storage con-tainer and then later loaded into transport vehicles by aux-iliary equipment.

By the end of 2000, there were 304 transfer stations inthe main districts of Chongqing. In 2004, there will be469 MSW transfer stations (23,205 m2) with a total trans-ferring capacity of 3000 t/d. The typical layout of the trans-

fer station is a two-story building. The collected MSW istemporally stored in the MWS holding facility that has atrap door through the ceiling of the first floor. The truckcan enter the first floor, and when the trap door in the ceil-ing is opened, the temporarily stored MSW can be auto-matically dumped into the truck. In terms of sanitation,these transfer stations are well managed and maintained.

3.3. Recycling and treatment

About 6.9% of all USW in Chongqing is incinerated andonly 1.8% is composted. According to 1999 data, theamount disposed of by simple landfills was about 91%,(Li and Gu, 2001).

3.3.1. Recycling

In recycling, waste materials are processed for industrialuse and then reformed into new or similar products.Recycling is often viewed as a resource conservationactivity and it may also offer a greater return for manyproducts in energy savings. The recyclable materials inChongqing�s MSW are paper, plastic and metal. InChongqing, each recyclable beer bottle is worth about¥0.1–0.2 (US$0.01–0.02), each aluminum soda can, ¥0.05(less than US$0.01) and each plastic bottle, ¥0.05–0.1(US$0.01). Waste paper and magazines are worth about¥0.2–0.4 (US$0.02–0.05) per kg. These recyclable materialsare often collected at the source or in waste bins byscavengers and reusable waste collectors patrollingdifferent residential areas. After collection, these items aresent to factories for recycling.

3.3.2. Composting

This second means of recapturing value of MSW isthrough the use of the natural biodegradation process.Composting is widely used in Western countries, but inChongqing Municipality, the composting method is rarelyused because of several market reasons:

1. Because sorting urban solid wastes is not widely prac-ticed by residents, sorting equipment must first be pur-chased before composting can take place. Thisequipment cost would make the price of compost higherthan fertilizer.

2. The public acceptance of composting is low, becausemost farmers have psychological resistance to the prod-ucts derived from wastes.

3. The usefulness of compost is limited. The compost hasless fertility than the chemical fertilizer. Compost canonly be used to grow non-food products such as publicgreen spaces. This lack of demand would cause seriousproblems for survival of the compost company.

4. Strict regulations, monitoring and quality standardswhich prevent the second pollution of compost is notadequate; therefore, composting is currently not a rec-ommended method (Zhang and Li, 2000).


3.3.3. Incineration

The third approach to recapturing the value of MSW isto convert the energy stored in waste by incineration.Although many combustibles are recyclable, there is oftena higher total value in burning the waste for energy than inrecycling it. Currently, only the Yubei MSW treatmentsites have simple incineration facilities (40 t/d), but thesesites have no effective waste gas controlling systemand the energy generated by the furnace cannot yet beutilized.

As stated previously, only 6.9% of the USW in Chongq-ing is disposed of through incineration. There is currentlyone functional incineration facility in Chongqing, One isin the Yubei treatment site. The other facility in Xinglonghas been shut down. But these are both simple incinerationfacilities. When the USW are transferred to the treatmentsites, they are hand-sorted for recyclable items. After segre-gation by gravity separation and vibratory screening, theyare sent to the incineration facilities.

Chongqing�s first modern incineration plant is nowunder construction. Tongxing Incineration Plant, locatedin Tongxing Town, Beibei district, has a capacity of 1000t/d. About 28% of all the urban solid waste in Chongqingwill be sent to the Tongxing Incineration Plant. This incin-eration plant will be equipped with two SITY2000 gratesprovided by MARTIN GmbH; these grates will be suitablefor waste with a high moisture content, a high percentageof incombustibles and a low net caloric value. This plantwill be equipped with a pollution control system and elec-tricity generation facilities (2 · 12,000 kW). This pollutioncontrol system will ensure that the discharge not only meetsthe Chinese standards for pollution control for municipalsolid waste incineration, but also can meet the Europeanpollution control standards for municipal solid waste incin-eration. The schedule for start of operations is at the end of2004.

3.4. Disposal systems

3.4.1. Simple landfill

In past years, a simple landfill or dump was used forurban solid waste disposal in Chongqing main districts.This simple landfill treatment method is still broadly usedin many cities of China. Because the main districts are hillyin terrain, the simple landfill sites were built in the hollowsbetween hills, and the waste was put into the pits fromabove. The simple landfill is a disposal method in which

Table 4Simple MSW treatment sites in Chongqing

Location: Qilongcun Renjiawan Xinglong LongtousiService area(District):

Yuzhong Nan�an Nan�an JiulongpoDadukou

Jiangbei

Area (ha) 20 3 4.4 5.2Capacity (t/d) 1000 300 500 400

Data sources: Department of Resource and Environmental Science, Chongqin

solid waste is disposed of in a manner that is not environ-mentally sound; waste is often exposed to the elements,vectors and scavengers, and susceptible to open burningor combustion with only minimal dust removal facilities.Its pollution-control facilities were always simple and lowin effectiveness. Therefore, the simple landfill had seriousenvironmental problems caused by untreated leachateand lack of covering clay.

There were nine simple landfill sites (Table 4) in themain districts of Chongqing Municipality; these simplelandfills� total disposal capacities were below the amountof daily urban solid waste generation. Most of these simpleMSW treatment sites had MSW separation, compost andincineration or landfill facilities, but because of cost andmarket reasons, the compost and incineration facilitieswere not in use. Since these simple landfill sites were scat-tered in Chongqing, and could not meet the standards ofenvironmental sanitation, Chongqing has now convertedto centralized disposal and has constructed standardized,modern sanitary landfills in order to improve urban solidwaste disposal methods and management. Currently onlytwo out of the original nine simple landfill sites are stillopen and operating – one in Yubei and the other in Beibei– and they will be closed when Heishizi Sanitary Landfillsite and Tongxing Incineration plant are opened.

3.4.2. Sanitary landfill

Because of the harm caused by simple landfills, Chon-gqing is now using new and standardized MSW treat-ment methods to protect the environment and people�shealth. The first standard sanitary landfill in Chongqingwas the Changshengqiao Sanitary landfill which finishedconstruction and opened in June 2003 (Fig. 6). The totalinvestment costs were ¥480 million (US$57.8 million),half of which was financed by the World Bank. Chang-shengqiao Sanitary Landfill is south of the main districtsand covers an area of 68 ha. Its capacity is 1500 t/d,serving five of the nine main districts. It is designed for20 years of service. This landfill employs an engineeredmethod of disposing solid wastes on land in a mannerthat minimizes environmental hazards by spreading thesolid waste in thin layers, compacting the solid wastesto the smallest practical volume and applying a coverat the end of the operating day.

The USW collected at the transfer station is delivered byvehicles to the temporary piling station of the sanitarylandfill, then is sent to the operation site for final disposal

Liangfengya Jinggangbei Yubei Jigongtai Liujiaolanya TotalShapingba Beibei Yubei Banan Jiulongpo

2.8 2 1.4 1.4 1.3550 300 150 Closed Closed 3240

g University.

Collected MSW

Environmental monitoring Sanitation protection Weighing

Operation Transferred to

Closure andthe operation section Compacted Covering PlacementUnloading utilization

Landfill gas Runoff Leachate

Surface water Collection Collection pipe drainage system

Treatment Combustion

Discharge

Fig. 6. Flowchart of Changshengqiao sanitary landfill site in Chongqing.


by compression dumping vehicles (5–8 t). Leachate gener-ated within the sanitary landfill is collected and treated ata leachate treatment station to the first level of theNational Effluent Discharge Standards specified by theState Environmental Protection Agency of China beforebeing discharged into the river.

The daily operational costs of Changshengqiao SanitaryLandfill site are about ¥88/t (US$10.63/t), and the collec-tion and transportation cost of the MSW is about ¥45/t(US$5.42/t). Treatment of leachate by the osmotic mem-brane costs about ¥2/t (US$2.41/t).

As landfill capacity is less than the total amount ofUSW generated per day, a second standard sanitarylandfill facility, Heishizi Sanitary Landfill, is now underconstruction. This sanitary landfill is located in the northof Chongqing�s main districts, covering the districts northof the Jialing River. The landfill�s total design capacity is1000 t/d and it is expected that it will be in operation for25 years of service. According to the design, by the 5thyear of the landfill�s operation, the methane generatedin the landfill will be able to be utilized to generate elec-tricity. The amount of electricity that can be generated isestimated to be about 6.75 million kW/yr with a profit ofmore than ¥3 million (US $0.36 million) per year forabout 25 years. As mentioned above, these two sanitarylandfill sites will be designed, constructed and operatedby the Environmental and Sanitary Protection HoldingGroups.

4. Problems and perspectives

4.1. Problems

4.1.1. Pollution caused by simple landfill sites and unsuitable

site selection

As Chongqing develops economically and grows in pop-ulation, the problems of urban solid waste management

become more and more important to solve. Over time,Chongqing�s urban population will grow, spreading intothe less populated surrounding areas of the city; simplelandfill sites formerly located in the suburbs now existwithin city limits. Because in these simple landfills only anegligible quantity of leachate is treated before being dis-charged into the groundwater, this situation will devaluethe land nearby, pollute the water, land and air as well asendanger the health of more and more people. Althoughthere are two near standard sanitary landfill facilities(Changshengqiao and Heishizi) being built, occupying sucha large area of land is not economically sound for Chongq-ing�s main districts because of the high population densityand high real estate value. After the simple landfill sitesclose, these occupied sites will soon become a part ofChongqing�s urban area and the land will need to be needre-used in a more practical manner. Therefore, a futurechallenge for Chongqing is to find a way to speed up therecovery and stabilization of the landfill sites so that theland can serve a new purpose.

4.1.2. Low LHV of the MSW is an impediment to the

implementation of incinerationThe characteristics of Chongqing�s USW result in three

main problems when considering disposal by incineration.First, the high moisture content and low caloric value ofthe USW result in unstable incineration. Second, an analy-sis of USW also suggests that any energy benefits generatedby incineration do not pay off economically. Third, USWwith a relatively high moisture content has a tendency toerode the incineration systems. As a result, landfills wouldbe the most effective and efficient and, therefore, mostdominant method of disposal. But there is one major disad-vantage to landfilling, even though they can meet thedemands of MSW disposal standards, this method of dis-posal must utilize a large land area – land that is scarce inthis populous city. This is the main reason why incineration


of solid waste has a promising future in Chongqing – itrequires less land utilization. However, if incineration isto be broadly adopted in the future, prevention of dioxinsand fly ash pollution will be a particularly urgent problemand challenge for Chongqing as the area�s hilly topogra-phy, low wind velocity, high frequency of static breezeand already existing air pollution issues are not conduciveto handling additional stressful factors on air quality.

4.1.3. Lack of an efficient and suitable MSW collection

method in Chongqing

The low combustibility and caloric value of Chongq-ing�s urban solid waste is caused by the sorting that scav-engers and reusable waste collectors do at the refusedisposal sites. The refuse in waste containers starts outin a mixed state with all types of solid waste combinedtogether, but scavengers and reusable waste collectorssort through to remove recyclable and reusable items.After they are through, often most of the paper andother combustibles have been removed leaving only thenon-combustibles. Therefore, on the one hand, wastescavengers and reusable waste collectors play an impor-tant role as an informal waste recovery system (Liu,2003), but on the other hand, they create a situation thatlowers the caloric value of solid waste and makes incin-eration a less viable solution for waste disposal in Chon-gqing. There are also some additional problems thatneed to be solved. For example, rummaging throughthe solid waste has a negative impact on the healthand hygiene of these scavengers and waste collectors.In addition, the waste collectors are quite selective aboutwhich types of waste they will take away; waste witheconomic value like paper and beer bottles will be sortedand removed but other types of waste such as batteriesare left behind, causing harm to the environment. Unfor-tunately, these informal waste recovery systems make itharder to regulate and implement a more efficient andstandardize waste treatment system. This kind ofinformal waste recovery system occurs in other cities ofChina (Chung and Poon, 1998b) as well as other devel-oping countries in Asia such as in India (Sudhir et al.,1996).

4.1.4. Lack of the standby MSW disposal capacity

As the Chongqing�s population grows, so too will theamount of USW. It has been forecast that by the year2020 (Lin, 2003), the total amount of urban solid wastegenerated will be 4664.4 t/d. Also the 1996–2000 Environ-mental Sanitary Protection Plan (CMAC, 1997) states thatby the end of 2010, the rate of MSW disposal will be 100%in the main districts of Chongqing Municipality. Althoughthe present disposal capacity of MSW has met the demand,there is not enough standby capacity. In Kitakyushu city,Japan, there is a standby capacity of 34% more than thecurrent amount of urban solid waste generated. The lackof standby disposal capacity will be a problem in thefuture, and unfortunately because of current challenges

regarding the lack of land for additional landfills, poorquality waste for incineration (Huang et al., 2003) andthe low value of compost (Zhang and Li, 2000), this prob-lem is not likely to be solved easily.

4.2. Opportunities and perspectives

In the future, to meet the needs of an integrated solidwaste management system, the following aspects shouldbe improved:

4.2.1. Perfecting the existing waste fees system

Lack of financial support is an obstacle in the localwaste collection system. The amount of funding allocatedfor sanitation and environmental protection in Chongqingis much lower when compared with other large Chinese cit-ies; the average amount Chongqing spent on sanitation andenvironmental protection per capita is only 8% of that ofShanghai (Liu, 2003). In Chongqing�s main districts, theMSW fee per household is now ¥3/mo (US$0.36/mo)(CMG, 2000), which is much lower than that in other bigcities of China. The waste fee levying system should beimproved so that the fees charged can provide adequatefinancial support to the existing urban solid waste disposalfacilities and finance programs to reduce the quantity ofurban solid waste generated.

4.2.2. MSW collection methods should be specialized

according to each district�s individual situations

Because different districts may have different economicsituations, efficient and effective separation and collectionof solid waste materials may require different methodolo-gies. The investigation shows that citizens are highly awareof the usefulness of sorting the refuse; they understand thatsorting their refuse before collection will reduce the amountof solid waste produced and facilitate the recycling of mate-rials as well as reduce the overall cost of waste disposal. Inaddition, sorting out the food waste from MSW and con-verting this organic refuse into compost will reduce theoverall moisture content of the urban solid waste. Shouldincineration become an option for MSW disposal, MSWwith a lower moisture content than currently will increasethe efficiency and cost effectiveness of the facility.

4.2.3. Improving the waste collection systems

Currently, Chongqing has an informal waste sorting,collection and recovery system made up of scavengersand patrolling reusable waste collectors. The local govern-ment should consider organizing and managing this infor-mal system so that it can be better regulated andformalized into a waste collection plan overseen by themunicipal institutions. Not only would this improve theefficiency of urban solid waste collection and recovery,but it would also provide job opportunities for these infor-mal waste collectors as well as better protect their healthand welfare. More detailed research is needed on manage-ment methods.


4.2.4. Implementing an integrated disposal method

Based on current household-sorted waste, when foodrefuse, recyclables and reusable items are sorted out fromthe main bulk of MSW, the moisture content will decreaseand the net caloric value of the remaining MSW willincrease. This change would be an advantage when inciner-ating waste. The ash generated after incineration could bedisposed at the landfill site. This integrated final disposalmethod would reduce the quantity of the urban solid waste,thereby relieving the pressure of the ChangshengqiaoSanitary Landfill and Heishizi Sanitary Landfill sites, andTongxing Incineration Plant. Nevertheless, in the future,Chongqing should enlarge its waste disposal capacityaccording to the amount of urban solid waste growth toavoid the actual disposal capacity decline under some acci-dental circumstances.

5. Conclusions

Due to the rapid urbanization, economic developmentand population growth, the amount of the USW is increas-ing at a rate of about 6%. In the main districts of Chongq-ing, the average amount of USW generated is about1.08 kg/d per capita in 2001. This is an increase from0.95 kg/d per capita in 1996, representing an increase ofabout 13.7%. Chongqing�s MSW has an average net caloricvalue of 3728 kJ/kg. Food waste represents a significantproportion of total MSW risings, and accounts for about59% of total solid waste production. The remaining wasteis made up of plastic (15.7%), paper (10.1%), fiber (6.1%),wood (4.2%), glass (3.4%), metals (1.1%) and rubber(0.3%). The high concentration of food waste is relatedto Chinese eating habits; Chinese people prefer their foodunprocessed with little packaging. Due to the low amountsof packaging, this preference leads to waste that has ahigher proportion of organic food waste.

Sorting and separating waste at the source is consideredto be an effective method of recycling waste items. At pres-ent, USW collection consists of different categories of wasteitems mixed together; however, some attempts of sortingbefore collection have been made with street-side roadrefuse. An investigation of the public awareness and educa-tion indicates that residents are concerned about solidwaste removal and believe that there are advantages to sortwaste before removal. These results shows that as the econ-omy grows and standard of living increases, Chongqingresidents are becoming more and more concerned aboutenvironmental conditions and corresponding effects ontheir health. To address these concerns, the Chongqinggovernment should implement a system that encouragescitizens to separate their waste before collection.

About 90% of Chongqing�s total USW is disposed insanitary landfills and simple landfills. Since the net caloricvalue of Chongqing�s USW meets the minimal require-ments for successful incineration, an integrated disposalmethod should be implemented in Chongqing. This inte-grated disposal method should include the following: (1)

improving the existing waste fees system; (2) specializedseparation and collection methods based on each district�sindividual needs; (3) improving waste collection systems;(4) implementing an integrated disposal method.

Acknowledgments

The investigation in 2002 was done in collaboration withKitakyushu Environmental Cooperation Center. We alsowould like to extend our appreciation to Sharlene Yangfor English editing and revision. We also would like tothank several anonymous reviewers for their inspiringand constructive comments of the paper.

References

Bai, R., Sutanto, M., 2002. The Practice and callenges of solid wastemanagement in Singapore. Waste Manage. 22, 557–567.

Chongqing Municipal Administration Committee, 1997. EnvironmentalSanitary Plan for Chongqing�s Main districts. Chongqing, China.

Chongqing Environmental Protection Bureau, 2001. EnvironmentalCommunique of Chongqing 2002. Chongqing, China

Chongqing Municipality Government, 2000, Legislations of the MunicipalSolid wastes� disposal fees in Chongqing Main districts. Governmentof Chongqing Municipality 2000/79. Chongqing, China.

Chung, S.S., Poon, C.S., 1998a. A comparison of waste management inGuangzhou and Hong Kong. Resources, Conserv. Recycling 22, 203–216.

Chung, S.S., Poon, C.S., 1998b. Recovery systems in Guangzhou andHong Kong. Resources, Conserv. Recycling 23, 29–45.

Dong, S.S., Tong, K.W., Wu, Y.P., 2001. Municipal solid wastemanagement in China: using commercial management to solve agrowing problem. Utilities Policy 10, 7–11.

Huang, B.S., Li, X.H., Wang, L.A., et al., 2003. Analysis of physico-chemical property and discussion of dispose of MSW in urban zone ofChongqing City. J. Chongqing University (Natural Science Edition)26, 9–13.

Hu, D., Wang, R.S., Yan, J.S., Xu, C., Wang, Y.B., 1998. A pilotecological engineering project for municipal solid waste reduction,disinfection, regeneration and industrialization in Guanghan City,China. Ecol. Eng. 11, 129–138.

Hunsicker, M.D., Crockett, T.R., Labode, B.M.A., 1996. An overview ofthe municipal waste incineration industry in Asia and the formerSoviet Union. J. Hazardous Mater. 47, 31–42.

Sundeqvist, Jan-Olof, 1999. Life cycles assessments and solid waste –guidelines for solid waste treatment and disposal in LCA. Report,IVL, Swedish Environmental Research Institute, Stockholm,Sweden.

Li, Dong, Gu, H.Y., 2001. Investigation and analysis of Municipalsolid waste status in Chongqing. Chongqing Environ. Sci. 23, 67–69.

Lin, J.W., 2003. The Planning Model and Application of Municipal SolidWaster Administration. Master Dissertation of ChongqingUniversity.

Liu, L., 2003. An Approach of Multi-level Modeling and GIS forRecycling Behavior. Master Dissertation of Chongqing University,Chongqing, China.

Qi, J.G., 2004, Institute of econometrics and techno-economics of Chineseacademy of social sciences. In: Proceedings of the fifth ChineseEconomists� Forum and 2004 China�s International Workshop on theAnalysis and Forecast of the Social Economic Situation, Beijing,China.

Su, F.W., Wang, L.A., 2003. Feasibility study on ISWM in Sanxia, Projectproposal, Chongqing University.


Sudhir, V., Muraleedharan, V.R., Srinivasan, G., 1996. Integrated solidwaste management in Urban India: a critical operational researchframework. Socio-Economic Planning Sci. 30, 163–181.

Tchobanoglus, G., Theisen, H., Vigil, S.A., 1993. Integrated solid wastemanagement, engineering principles and management issues, McGraw-

Hill for mainland China edition. McGraw-Hill Companies Inc., andTsinghua University Press, Beijing, China.

Zhang, X.D., Li, D., 2000. MSW treatment techniques informative forChongqing. J. Chongqing University (Natural Science Edition) 23, 53–57.

Urban solid waste management in Chongqing: Challenges and opportunities

Documents

Transcript of Urban solid waste management in Chongqing: Challenges and opportunities