WMR0010.1177/0734242X14521685Waste Management & ResearchAn et al.

Short Report

Generation, collection and transportation, disposal and recycling of kitchen waste: A case study in Shanghai

Waste Management & Research 2014, Vol. 32(3) 245­–248 © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0734242X14521685 wmr.sagepub.com

Ying An1, Guangming Li1, Wenqing Wu2, Juwen Huang1, Wenzhi He1 and Haochen Zhu1

Abstract With respect to waste sorting, Shanghai sets an example for other Chinese cities on the standardized treatment of kitchen waste (KW) in China. According to the results of investigation, about 560 kilo tons of KW from different sources in Shanghai were produced in 2011. Of this, 45.6% (255.6 kilo tons) was collected and transported properly by a comprehensive and formal collection and transportation system. Landfilling and incineration, which are the traditional treatment technologies used, show downward trends because of increasing environmental awareness and land restrictions. Feed production, composting and biodiesel refining play increasingly important roles in the recycling of KW. Safe disposal, reduced KW quantity, public education, and technological innovation are still problematic issues and need to be considered in future waste management in Shanghai. Keywords Kitchen Waste, generation, collection and transportation, disposal, recycling, Shanghai

Introduction Kitchen waste (KW), as the main part of municipal solid waste (MSW) in China, has increased dramatically in quantity by about 10%/year from 2001 to 2009 (Chen et al., 2010; Iacovidou et al., 2012; Rajagopal et al., 2013). In 2009, China generated about 50 million tons of KW, which corresponds to 0.1 kg·d-1 per capita (Li et al., 2009). Shanghai is the first city to focus on improving tKW management and is currently the leader in the country. KW generation in Shanghai increased by 10–15%/year during from 2002 to 2011 (Sciences Academy of Shanghai Environmental Engineering Design, 2011). KW in Shanghai has traditionally been delivered to pig farms as a feed without any specific treatment. Thus, there is a risk that hazardous compounds and pathogens present in the KW may be consumed by humans through the food chain. In addition, some illegal restaurants recycle waste oils/greases originating from refining and slops oil that has already entered the food market, constituting a serious threat to human health. In order to regulate KW processing, Shanghai has proposed several regulations for KW management, but these standards and regulations have not been effectively implemented owing to inadequate management capabilities and misappropriation of resources. How to dispose of a huge amount of KW is a challenge faced by both the government and inhabitants. While literature focusing on MSW generation, collection, recycling and disposal in China and other countries is available, information on KW management in specific cities of China is rare. This report therefore

attempts to discuss the generation, collection and transportation (C&T), disposal and recycling of KW in Shanghai to illustrate the great endeavor in KW management, and also to provide a case study that may form the basis for improved management of specific fractions of solid waste in China and elsewhere.

KW generation in Shanghai Based on the catering service licensing examination standard drafted on 17 June 2010, the catering service is divided into five types, which refer to the type of operation (SFDA, 2010). It included restaurants, nosheries (informal restaurants), snack bars, drink shops and canteens. Restaurants are classified into four categories depending on size. The specific distribution and number of different catering types in each district of Shanghai are shown in Figure 1. In Shanghai there are 16,220 nosheries, 2630 1State

Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China 2Shanghai Waste Administrative Division, Shanghai, China Corresponding author: Guangming Li, State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, China. Email: [email protected]

Downloaded from wmr.sagepub.com at EMORY UNIV on April 19, 2015


Waste Management & Research 32(3)

Figure 1.  Distribution of kitchen waste among different types of catering operations. Table 1.  Collection and transportation (C&T) conditions for kitchen waste in Shanghai. Items

Annual C&T (kilo tons)

Daily C&T (tons)

Certified enterprises

Registered personnel

  Food waste Waste oils/ greases Total

Special vehicles Total

Automotive vehicle



150 262

36 99

17  3

241.8 13.8

662.5 37.8

45 25

404 441

203 364






Source: Statistics from Shanghai Waste Administration Division, 2011.

snack bars, 7963 drink shops and 16,341 canteens. The Pudong district, a newly developed zone, possesses a large number of restaurants, canteens and drink shops compared with other districts and are located here owing to the fact that the are has a lot of factories with thousands of industrial workers. Songjiang, Qingpu, Minhang and Pudong districts share the majority of canteens. In addition, staff dining rooms in university towns are major contributors to KW in Songjiang district. The total number of restaurants of various sizes is about 19,000 and the category of small restaurants (< 150 m2 or 75 seats) are the main contributors of KW. According to the ‘Kitchen waste generation amount investigation report in Shanghai’ (Sciences Academy of Shanghai Environmental Engineering Design, 2011), the total annual amount of KW output in 2011 was about 560 kilo tons, which is equivalent to 1537 t d-1, and accounted for 24% of MSW produced in Shanghai. Consequently, suitable C&T and disposal is of great important for KW management in Shanghai.

C&T Total C&T amount of KW increased by 43.23% from 145.1 to 255.6 kilo tons between 2006 and 2011, accounting for 45.6% of the total output in 2011. Food waste accounted for 241.8 kilo

tons, and waste oils/greases for 13.8 kilo tons. This is equivalent to 700.3 tons per day on average, out of which food waste and waste oils/greases constitute 662.5 and 37.8 tons, respectively. In 2011, there were 45 and 25 certified C&T companies for food waste and waste oils/greases in Shanghai, respectively. Registered personnel was 845, with 404 and 441 for food waste and waste oils/greases C&T, respectively. There were 567 special vehicles in Shanghai, which were composed of 203 and 364 trucks for each collection, respectively. An overview of waste quantities and transportation conditions in Shanghai in 2011 is given in Table 1. According to statistical data for collected and transported quantities of KW for each district in Shanghai, Minhang, Pudong and Changning districts, which had a comprehensive and formal C&T systems, ranked as the top three districts in terms of the amount of KW collected in 2011 (Figure 2). Minhang district, which had the highest amount of KW collected (51.6 kilo tons), had a normalized collection system and it has been identified as one of the nation’s first KW C&T pilot sites. A series of standardization mode operations for C&T will be carried out and the technology will be popularized in Shanghai and then expanded to the whole of China. Compared with food waste, the C&T of waste oils/greases is just beginning, so the current amount of this type of waste that is collected and transported is relatively low.

Downloaded from wmr.sagepub.com at EMORY UNIV on April 19, 2015


An et al.

Figure 2.  Kitchen waste collection and transportation in Shanghai districts in 2011. Table 2.  Overview of kitchen waste disposal enterprises in Shanghai and treatment methods. No.

Disposal enterprises


Huanxing Food Waste Disposal Plant Shanghai Bangxu S&T Limited Company Changning Food Waste Disposal Plant Shanghai Aoxue Biotechnology Limited Company Shanghai Aoxue Biotechnology Limited Company Shanghai Food Waste Disposal Limited Company Kelin Eeathworm Breed Aquatics Limited Company Xiayu hi-tech Limited Company Zhongqi Environmental Protection S&T Limited Company Lvming Environmental S&T Limited Company

2 3 4 5 6 7 8 9 10 Total

Designed disposal capacity (t d-1)

Actual disposal capacity (t d-1)

Service area (district of Shanghai)

Terminal production




Feed supplement




Earthworm feed




Feed supplement




Organic manure



Parts of Pudong

Organic manure



Feed supplement



Minhang, Luwan, Xuhui Baoshan, Zhabei

Earthworm feed

50 45

20 55

Fengxian Fengxian

Feed supplement Biodiesel







Disposal and recycling Owing to land restrictions and large quantities of leachate, landfilling is not the main disposal method for KW in Shanghai. Only Laogang landfill, which has run from the 1980s until now, is receiving KW. Previously, a large bulk of KW mixed with MSW was handled directly by incinerators. This process would not only lower thermal energy utilization, but also aggravated the generation of toxic compounds. The technological innovation of landfilling and incineration, however, has improved these to comply with environmental protection regulations. At the same time, resource recycling is becoming increasingly important, especially for megacities like Shanghai. Until now, eight KW treatment plants and two waste edible oils/greases secondary processing plants have been built for

recycling. Designed disposal capacities are 600 t d-1 for feed and fertilizer, and 75t d-1 for biodiesel. As shown in Table 2, the actual disposal capacity is less than designed. This is mainly owing to poor waste quality and insufficient waste quantity, as a result of two main factors: first, source separation of KW from MSW is often incomplete, which leads to a large proportion of KW being mixed with other MSW and therefore ending up in landfills or incineration plants; and, second, restaurant profit is an important factor. Not only are actual KW generation rates sometimes misreported to reduce disposal costs, but the majority of KW is also sometimes sold as pig feed or for waste oil refining through illegal channels. In China, KW is legal to use as animal feed, provided that the food quality and safety is ensured. Key treatment steps for animal feed production for the companies shown in Table 2 are

Downloaded from wmr.sagepub.com at EMORY UNIV on April 19, 2015


Waste Management & Research 32(3)

high-temperature drying for moisture reduction, protein quality enhancement and pathogen inactivation. Composting involves the use of microorganisms to break down organic residues in presence of oxygen, thus avoiding the production of methane (Khoo et al., 2010; Schleiss, 2008). In Shanghai Aoxue Biotechnology Limited Company, the bacterially-mediated aerobic thermophilic stage in composting is generally followed by a maturation stage involving action of various earthworms. Its composting technology has reduced both residence times for the active composting stage from several weeks to 72 h, and the maturation stage from months to weeks, while new developments in vermiculture have also allowed single-stage vermiculture to be conducted on a large scale. There are two secondary processing plants for producing biodiesel from waste oil/grease in Shanghai. Production is based on acid–base treatment, centrifugation, de-coloration, and plate-frame filtration in sequence. The processing capacity of Shanghai Zhongqi Environmental Protection Limited Company is 16,000–20,000 tons year-1. It is a typical transesterification technology, and the conversion rate for KW is about 80%.

Conclusions In Shanghai, the average amount of KW output was about 1537 tons day-1, accounting for 24% of the MSW produced in 2011. Meanwhile, the total C&T amount of KW was 255.6 kilo tons, which accounts for 45.6% of total output. The districts with more comprehensive and formal C&T systems had better collection and transport performance. Landfilling and incineration are facing increased challenges with respect to environmental restrictions and land shortage. Animal feed, composting and biodiesel production play important roles in transforming and upgrading traditional KW treatment processes. In addition, improving

source separation, reducing gross KW production, enhancing public sense of participation and developing effective KW conversion processes are essential steps in improving future KW management.

Declaration of conflicting interests The authors do not have any potential conflicts of interest to declare.

Funding This study was financially supported by Grant of State Science and Technology Support Program (No. 2010BAK69B24) and Grant of Shanghai Science and Technology Committee (No. 10dz0583200).

References Chen X, Geng Y and Fujita T (2010). An overview of municipal solid waste management in China. Waste Management 30: 716–724. Iacovidou E, Ohandja DG and Voulvoulis N (2012) Food waste co-digestion with sewage sludge – Realising its potential in the UK. Journal of Environmental Management 112: 267–274. Khoo HH, Lim TZ and Tan RBH (2010) Food waste conversion options in Singapore: Environmental impacts based on an LCA perspective. Science of the Total Environment 408: 1367–1373. Li J, Liu LF and Zhang Q (2009) Review of livestock feed from kitchen waste (in Chinese). Feed Industry 30: 54–57. Rajagopal R, Lim JW, Mao Y, Chen CL and Wang JY (2013) Anaerobic co-digestion of source segregated brown water (feces-without-urine) and food waste: For Singapore context. Science of the Total Environment 443: 877–886. Schleiss K (2008) GHG savings from biological treatment and application of compost, prod. moving organic waste recycling towards resource management and biobased economy. In: 6th international conference, ECN/ORBIT e.V. workshop, Wageningen, the Netherlands, 13–15 October 2008. Sciences Academy of Shanghai Environmental Engineering Design (2011) Kitchen Waste generation amount investigation report in Shanghai. SFDA (State Food and Drug Administration) (2010) Catering service licensing examination standard.

Downloaded from wmr.sagepub.com at EMORY UNIV on April 19, 2015

Generation, collection and transportation, disposal and recycling of kitchen waste: a case study in Shanghai.

With respect to waste sorting, Shanghai sets an example for other Chinese cities on the standardized treatment of kitchen waste (KW) in China. Accordi...
2MB Sizes 0 Downloads 3 Views