Emissions from MSW

Tian, H.H., Ouyang, N., 2003. Preliminary investigation on dioxins emission from MSW incinerators. Environmental Chemistry 22 (3), 255-258 (in Chinese). 

To develop national guidelines for emissions from MSW incinerators. 

Dutch Studies. In a study examining emissions from MSW incinerators operating in the Netherlands, a number of emission types were measured acid, gases, organics, particulates, CO, etc.20 The relationship between particulate and PCDD/F emissions was tested. In presenting a plot of these emissions, the report stated that no really clear correlations emerge. ... 

Recent tests provide an excellent example of the control of PCDD/F emissions from MSW combustion facilities.46 Tables 4 and 5 reproduce the results of a multiple regression analysis on operating variables relevant to the combustion system (i.e. before the combustion gases enter the pollution abatement equipment). 

Emissions from MSW incinerators operating under good conditions are in the range of 1-100 ng TCDD equivalents /Nm resulting... 

Hazardous waste incinerators. Hazardous waste incinerators have also been the object of public concern. However, available data indicate the emissions from such incinerators operating under good conditions are of the same magnitude as emissions from MSW incinerators. The isomeric patterns of PCDDs and PCDFs are similar to those reported from MSW incinerators... 

An extreme good similarity was reported for the isomeric pattern of the tetra- and penta-CDFs found in automobile exhausts and in emissions from MSW incinerators (12) and steel mills, see Figure... 

Zeiss, C.A. 2006, Accelerated methane oxidation cover systems to reduce greenhouse gas emission from MSW landfills in cold-semi arid regions Water Air Soil Poll. 176 285-306. 

A preliminary investigation on dioxin emission from MSWI in China has been campaigned by Tian and Ouyang (2003). Flue gas of 15 different types of MSW incinerators was monitored. About half of the data exceeded the national standard for dioxin emissions limit (1 ng TEQ m-3 National Standard of the People s Republic of China, 2001) and the highest was at 100 ng TEQ m-3 level. However, this report did not provide precise concentrations. Total dioxin emissions to air from MSWI was estimated to be 72 ng TEQ annually in China based on the monitoring data of Tian and Ouyang (2003). Stack furnaces (with bag filters for dust removal) are the major type of MSW incinerators in China but not the major contributor to dioxin emissions. Fluid-bed furnaces accounted for 60% of the dioxin emissions from MSWI. 

The most relevant problem originating from MSW incineration is flue gas treatment, since untreated incineration flue gas can contain large amounts of macropollutants (e.g., CO, S02, HC1, NOx, particulates) andmicropollutants (e.g., PAHs, mercury compounds, polychlorinated biphenyls, dioxins, furans). The necessity of reducing polluting emissions to levels compatible with existing regulations dictates the adoption of rather sophisticated- and expensive flue gas treatment sections in incineration plants. 

Figure 1 Observed and predicted PCDD/F emissions from a MSW incinerator, using chlorobenzenes and chlorophenols as surrogates. (Taken from Oberg and Bergstrom25)...

The concentrations of mercury in the landfill gas were estimated with the aid of a simulation program EandGEM that was developed by the office of Research and Development United States Environmental Protection Agency (US EPA). Land GEM is based on a fust-order decomposition rate equation for quantifying emissions from the decomposition of landfilled waste in municipal solid waste (MSW) landfills. The software provides a relatively simple approach to estimating landfill gas emissions. Model defaults are based on empirical data from US landfills. Field test data can also be used in place of model defaults when available. This software was also useful to forecast the future levels of mercury generation from LEG. 

The current emission level of cadmium from MSW incinerators represent less than 2.0% of total atmospheric emissions of cadmium in the EU countries. The enforcement of the new EU Directive on emissions of cadmium gives a maximum permissible concentration of 0.05 mg/Nm. In these conditions, emissions associated to the... 

The second fraction of spent Ni-Cd batteries is introduced in landfills (as illustrated in Figure 22). The EC Directive on waste imposes a strict control of leachate emissions. More than 2,000 sites have been reviewed and 95% of them show cadmium concentrations in leachates below 5 micrograms per litre (Eggenberger 2000). This represents the recommended concentration of cadmium for drinking water by the World Health Organization (WHO). This low emission level from MSW landfills has been confirmed by Swedish researchers (Flyhammer 1996). 

Carbon-based processes (both direct injection and fixed-bed) have been developed for control of mercury emission from municipal- and hazardous-waste incinerators [10, llj. Existing data from the incinerators provide some insight on mercury control, but these data cannot be used directly for coal-fired utilities because mercury concentrations, species, and process conditions differ greatly [Ij. For example, municipal solid waste (MSW) mercury concentrations (200 to 1000 pg/m ) are one to two orders of magnitude larger than for flue gases generated by coal combustion sources. 

Emissions from waste combustion of various types will likely decline as well, given the mix of new rales on municipal solid waste (MSW) and hazardous waste combustion. Walsh et al. (2001) reported that in past decades, the late 1960s, MSW burning in the New York City area emitted up to ca. 800 MT Pb/year. 

Xiaofang, Y. (2008). Polycyclic aromatic hydrocarbon (PAH) emission from co-firing municipal solid waste (MSW) and coal in a fluidized bed incinerator, Waste Manage., 28, pp. 1543-1551. 

Formation of Airborne Emissions. Airborne emissions are formed from combustion of waste fuels as a function of certain physical and chemical reactions and mechanisms. In grate-fired systems, particulate emissions result from particles being swept through the furnace and boiler in the gaseous combustion products, and from incomplete oxidation of the soHd particles, with consequent char carryover. If pile burning is used, eg, the mass bum units employed for unprocessed MSW, typically only 20—25% of the unbumed soHds and inerts exit the combustion system as flyash. If spreader-stoker technologies are employed, between 75 and 90% of the unbumed soHds and inerts may exit the combustion system in the form of flyash. 

---