Agriculture Reference
In-Depth Information
1
Long-Term Monitoring of Dioxin and Furan
Level in Soil Around Medical Waste Incinerator
Li Xiao-dong, Yan Mi, Chen Tong, Lu Sheng-yong and Yan Jian-hua
State Key Laboratory of Clean Energy Utilization, Zhejiang University
Hangzhou City,
PR China
1. Introduction
The annual generation of solid waste is quite huge in China. For instance, approx. 157
million tons of municipal solid waste (MSW) and 2.04 billion tons of industrial solid waste
(14.29 million tons of hazardous waste) were produced in 2009 (National Bureau of Statistics
of China, 2010). These wastes would contaminate green land, drinking water and even air,
ultimately threatening human health, so they must be treated in scientific methods. Waste
treatment is a big challenge for every country. At present, the conventional disposal system
according the hierarchy of methodologies includes recycle, compost, combustion and
landfill. Combustion has noticeable advantages in volume and weight reduction,
disinfection and short time cost, can also realize energy recovery by using waste to energy
plants. Thermal treatment (pyrolysis and incineration) is the widely applied technology for
waste treatment, for instance, accounting for 18.2% of MSW treatment in China and 11.9% in
USA (2009). There are over 300 central incinerators for hazardous solid waste (HSW) in
China (National Development and Reform Commission of China, 2003) and 93 municipal
solid waste incinerators (National Bureau of Statistics of China, 2010). The present Chinese
regulations prohibit the co-combustion of HSW and MSW (Ministry of Environment
Protection, 2001).
However, waste incineration is still a controversial issue among social and scientific
communities due to its secondary pollution, especially after the observation of
polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in incinerators (Olie et
al., 1977). Waste incineration is thought a major source of PCDD/Fs in the environment.
UNEP (UNEP Chemical, 2005) published the standardized toolkit for identification and
quantification of dioxin and furan, including the emission factor of PCDD/Fs from
combustion and incineration. Research (Gao et al., 2009; Ni et al., 2009) shows the emission
factor of PCDD/Fs from medical waste incinerators (MWI) is nearly 63.3 µg I-TEQ/ton
refuse into the atmosphere and 1.73 µg I-TEQ/ton from municipal solid waste incinerators
(MSWI) in China, respectively. There are 135 dioxins and 175 furans, each with a different
number and position of the chlorine atoms. 17 congeners of PCDD/Fs with 2,3,7,8 positions
substituted by chorine are very toxic, which can induce a variety of adverse health
problems, such as sarcomas, lymphomas and stomach cancer (Mitrou et al., 2001). These
toxic pollutants can be formed by de novo synthesis and from precursor compounds
(McKay, 2002), be emitted into the air through the stack, and transported to the ambient air,
