Adsorption Behaviour of Tween 85 on Nano-Aluminium Particles in Aluminium/JP-10 Suspensions.

A stability analyser and a rheometer were used to study the effects of Tween 85 (polyoxyethylene sorbitan trioleate) on the dispersion properties of nano-aluminium/JP-10 (exo-tetrahydrodicyclopentadiene) suspensions. Results show that the addition of Tween 85 can effectively improve the stability of two-phase suspensions by hindering particle aggregation and reduce the viscosity of a system. The surface characteristics of the zeta potential and the contact angle were measured. The dispersion of the suspensions was improved by Tween 85 mainly by enhancing the steric hindrance of particles. The adsorbed particles obtained in JP-10 with different Tween 85 concentrations were analysed via scanning electron microscopy and Fourier transform infrared spectroscopy to explore the adsorption behaviour of Tween 85 molecules on the surface of aluminium particles and to confirm that Tween 85 formed an adsorption layer on the particle surface. Thermogravimetric analysis indicated that the adsorption amount of Tween 85 increased with its concentration in JP-10. The roughness analysis of the surface of adsorbed particles was measured via atomic force microscopy to characterise the thickness of the adsorption layer. The results showed that Tween 85 molecules formed an irregular adsorption layer on the particle surface, and an increase in the concentration of Tween 85 in JP-10 increased the thickness of the adsorption layer.

[Simulation of Concentration Measurement of SO(2), NO(2) and Particles Simultaneously by Differential Optical Absorption Spectroscopy].

Our daily life is disturbed seriously by the haze weather now. It is very important to measure the haze composition quantificationally. The main composition of haze is SO(2), NO(2) and particles. At present, the research of measuring gas and particle simultaneously is rare relatively. This paper use differential optical absorption spectroscopy (DOAS) to simulate the concentration measurement of gas and particle simultaneously and obtain some meaningful results. Absorption spectral of many groups of different concentration of SO(2), NO(2) and particle were simulated, and each concentration was inverted by DOAS. In the first group of single component, the concentration change from 100 to 1 000 ppm, the inverted error of SO(2) is not greater than 0.17%, and which is 0.64% for NO(2). When the diameter of particle change from 100 to 500 nm, the inverted error is not greater than 2.08%. In the second group of multiple gases, when the concentration ratio of SO(2) and NO(2) is at the range of 1 : 10 and 5 : 1, the error of SO(2) is not bigger than 8%, and 5% for NO(2), relatively. But when the concentration of SO(2) is 10 times than NO(2), the error is higher than 10% for NO(2). In the third group of gas and particle, the error of gas concentration is lower than 10%, but the concentration error of particle is depended on signal to noise ratio (SNR) greatly. When SNR is higher than 40 dB, error can lower than 10% and when SNR is lower than 30dB, the error is bigger than 20%. From these results, we can see that DOAS can measurement SO(2), NO(2) and particles simultaneously effectively, and can applied to measure and analyze haze composition. However, when the absorption strength of the gases is different greatly, the strong absorption gas influent the weak absorption gas largely. And the SNR is lower, the error of inverted particle concentration increased greatly. The solution of these problems need better filtering and noise reduction method.

[The Experimental Research on Reducing the Minimum Measureable Limit of Tunable Diode Laser Absorption Spectroscopy with Wavelet Analysis].

To obtain the weaker second harmonic signal of low concentration, reduce the minimum measurable limit and improve the sensitivity and accuracy of absorption measurement, a serious of data processing methods are proposed based on tunable diode laser wavelength modulation spectroscopy. The experiment on lower NH3 concentration at 2.25 µm was carried out in a 10.13 m absorption cell with different concentration. The peak height of the second harmonic signal is maximum at m=2.2, which optimizes the signal-to-noise ratio. In order to guarantee the optimal signal-to-noise ratio, the experiment was carried out by loading the optimal high frequency modulation signal. WMS-2f was performed at a repetitive scan rate of 200 Hz and a current-modulation rate of 15 kHz, wavelength modulation spectroscopy with the optimal signal-to-noise ratio was adopted for its better noise immunity to measure different lower NH3 concentration in the Herriott cell. This survey is focused on the ν2+ν3 bands of absorption spectra near 2.25 µm in near-infrared region at ambient temperature and pressure, the line strengths of 2.25 µm are much larger than the absorption lines in the telecommunication bands, using stronger NH3 absorption lines can offer the potential of lower detection limits. During the data processing, the background signal of the original harmonic should be deducted at first, the second harmonic signal of 0.6×10-6 was obtained in a 10 m long-path Herriott cell after data processing, these signal processing mainly consist of cross-correlation analysis, multiple averages and wavelet transform analysis, the cross-correlation analysis was used to control the shift of center wavelength, the multiple averages and wavelet transform analysis were used to reduce influences of the environment noise, after that we get the revised second harmonic signal and improve the accuracy of the measurement results. The experimental results show that these data processing methods can obviously improve the signal quality and reduce the minimum measurable limit about 100 times lower than before. The experiment doesn't need to add any laboratory equipment and can well restrain the influence of the environmental noise and other disturbance, so these signal process combined with wavelength modulation technique will be more useful for on-line gas detection technology.

[Research on the Distribution of Gas Concentration of Two-Dimensional Reconstruction Based on Tunable Diode Laser Absorption Spectroscopy with Multispectral Absorption].

The two-dimensional concentration distribution was reconstructed by using algebraic iterative reconstruction algorithm. This paper mainly focused on the effects of multispectral H2O absorptions on condition that the laser beam was less and the temperature was known, i.e. the influence of temperature on spectral line-strength was not considered as to this concentration distribution. Based on ART algorithm, increased spectral lines and increased laser beam were compared under the same concentration model. Three H2O lines were selected to reconstruct two-dimensional distribution of non-uniform gas concentration, and these three transitions were selected within the external cavity diode laser turning range in the simulated system. The interested region was discretized to 10×10 grid points, and the temperature and concentration of the reconstruction model were not evenly distributed, so the unimodal distribution and bimodal distribution were used to describe the concentration distribution. The simulated system also calculated the effective utilization of laser beams and absorption lines. The results showed that the reconstruction quality quickly increased with increasing H2O absorption lines when the laser beams were very few, the increased absorption lines could get more spectral information related to the concentration. The increased laser beam is also effective to improve the accuracy of reconstruction results, but increasing the absorption lines can better reconstruct a two-dimensional concentration distribution. Improving the absorption lines can also effectively reduce the costs of the hardware and the complexity of the measurement system, which shows that the multispectral absorption lines are applicable to in-situ measurements.

[The Research for Trace Ammonia Escape Monitoring System Based on Tunable Diode Laser Absorption Spectroscopy].

In order to on-line measure the trace ammonia slip of the commercial power plant in the future, this research seeks to measure the trace ammonia by using tunable diode laser absorption spectroscopy under ambient temperature and pressure, and at different temperatures, and the measuring temperature is about 650 K in the power plant. In recent years lasers have become commercially available in the near-infrared where the transitions are much stronger, and ammonia's spectroscopy is pretty complicated and the overlapping lines are difficult to resolve. A group of ammonia transitions near 4 433.5 cm(-1) in the v2 +v3 combination band have been thoroughly selected for detecting lower concentration by analyzing its absorption characteristic and considering other absorption interference in combustion gases where H2O and CO2 mole fraction are very large. To illustrate the potential for NH3 concentration measurements, predictions for NH3, H2O and CO2 are simultaneously simulated, NH3 absorption lines near 4 433.5 cm(-1) wavelength meet weaker H2O absorption than the commercial NH3 lines, and there is almost no CO2 absorption, all the parameters are based on the HITRAN database, and an improved detection limit was obtained for interference-free NH3 monitoring, this 2.25 µm band has line strengths several times larger than absorption lines in the 1.53 µm band which was often used by NH3 sensors for emission monitoring and analyzing. The measurement system was developed with a new Herriott cell and a heated gas cell realizing fast absorption measurements of high resolution, and combined with direct absorption and wavelenguh modulation based on tunable diode laser absorption spectroscopy at different temperatures. The lorentzian line shape is dominant at ambient temperature and pressure, and the estimated detectivity is approximately 0.225 x 10(-6) (SNR = 1) for the directed absorption spectroscopy, assuming a noise-equivalent absorbance of 1 x 10(-4). The heated cell experiments with controlled the temperature were performed to validate the sensing strategy. Here the Wavelength Modulation Spectroscopy (WMS) strategy was usually used to measure lower gas concentration for high noise immunity to the non-absorption transmission losses. The great agreement 2f signal with the calibrated concentration is within the uncertainty at different temperatures by using simple digital signal processing such as multiple averages, wavelet analysis and so on. The denoise processing has a great advantage in application and implementation over other noise suppression techniques. The result provided a good basis for trace ammonia escape detection based on tunable diode laser absorption spectroscopy.

Dioxins and their fingerprint in size-classified fly ash fractions from municipal solid waste incinerators in China--mechanical grate and fluidized bed units.

The distribution of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), in brief dioxins, has seldom been addressed systematically in fly ash from municipal solid waste incinerators (MSWIs). This study shows the amount and fingerprint of PCDD/Fs in fly ash from four different Chinese MSWIs, that is, three mechanical grate units and one circulating fluidized bed unit. In these fly ash samples, dioxins-related parameters (international toxic equivalent quantity, total amount of PCDD/Fs, individual isomer classes, and 17 toxic 2,3,7,8-substituted congeners) all tend to increase with decreasing particle size for mechanical grate incinerators, yet only for the finest fraction for fluidized bed units. Moreover, the fluidized bed incinerator seems superior to grate incineration in controlling dioxins, yet a comparison is hampered by internal differences in the sample, for example, the fluidized bed fly ash has much lower carbon and chlorine contents. In addition, the presence of sulfur from mixing coal as supplemental fuel to the MSW may poison the catalytic steps in dioxins formation and thus suppress the formation of dioxins. With more residual carbon and chlorine in the fly ash, it is easier to form dioxins during cooling. Nevertheless, there is no apparent relation between Fe, Cu, and Zn contents and that of dioxins in fly ash.

[The reconstruction of two-dimensional distributions of gas concentration in the flat flame based on tunable laser absorption spectroscopy].

The experimental method by using the tunable diode laser absorption spectroscopy combined with the model and algo- rithm was studied to reconstruct the two-dimensional distribution of gas concentration The feasibility of the reconstruction program was verified by numerical simulation A diagnostic system consisting of 24 lasers was built for the measurement of H2O in the methane/air premixed flame. The two-dimensional distribution of H2O concentration in the flame was reconstructed, showing that the reconstruction results reflect the real two-dimensional distribution of H2O concentration in the flame. This diagnostic scheme provides a promising solution for combustion control.

[Study of a wire-to-plate positive pulsed corona discharge reactor by emission spectroscopy].

In order to get extensive knowledge of wire-to-plate pulsed corona discharge reactor, the influences of different diameters of wire electrode, different wire-to-plate and wire-to-wire spacing on OH radical generation were experimentally investigated under atmospheric pressure based on emission spectrum, and the spatial distribution of OH radicals in the electric field was also discussed in detail The results showed that OH radicals decrease along the X-axis, and the activation radius is approximately 20 mm; showing a trend of first increase and then decrease along the Y-axis, with the activation radius being more than 30 mm. OH radical has small change as the diameter of wire electrode changes below 2 mm, with a sharp decline as the diameter continues to increase. OH radical emission intensity increases as wire-to-wire spacing increases and decrease as wire-to-plate spacing increases.

[Analysis of streamer properties and emission spectroscopy of 2-D OH distribution of pulsed corona discharge].

Streamer plays a key role in the process of OH radical generation. The propagation of primary and secondary streamers of positive wire-plate pulsed corona discharge was observed using a short gate ICCD in air environment. The influence of the applied voltage on the properties was investigated. It was shown that the primary streamer propagation velocity, electric coverage and length of secondary streamer increased significantly with increasing the applied voltage. Then 2-D OH distribution was investigated by the emission spectrum. With the analysis of the OH emission spectra, the distribution of OH radicals showed a trend of decreasing from the wire electrode to its circumambience. Compared with the streamer propagation trace, the authors found that OH radical distribution and streamer are in the same area. Both OH radical concentration and the intensity of streamer decreased when far away from the wire electrode.

[Study of emission spectroscopy of OH radicals in pulsed corona discharge].

In the present paper, OH radicals generated by pulsed corona discharge in humidified air, N2 and Ar in a needle-plate reactor were measured by emission spectra. With the analysis of the emission spectra, the influence of pulse peak voltage and frequency on OH radical generation was investigated in the three kinds of background gases. The influence of the gas humidity on the generation and the distribution of OH radicals in the electric field was also discussed in detail. The authors studied the influence of the gas humidity on the generation of OH radicals in the electric field by the control of accurate change in humidity, and we also studied the distribution of OH radicals in the electric field in different background gases including humidified air, N2 and Ar by the accurate change in scales. The experiment shows that the output of OH radicals grows as the pulse peak voltage and frequency grow, but the influence of gas humidity on the process of generating OH radicals by pulsed corona discharge depends on the discharge background. The rules of the generation change when the background gases change. As the humidity in the background gases grows, the amount of OH radicals grows in the air, but it grows at first and decreases at last in N2, while it decreases at first and grows at last in Ar. The distribution of OH radical shows a trend of decreasing from the needle-electrode to its circumambience.

Emission characteristics of volatile compounds during sludges drying process.

The emission characteristics of volatile compounds (VCs) during municipal sewage sludge (MSS) and paper mill sludge (PMS) drying process were investigated through experiments conducted on a lab-scale tubular drying furnace and a pilot-scale paddle dryer, respectively. The result indicated that five kinds of VCs, i.e. CO(2), NH(3), C(7)H(16) (n-heptane), volatile fatty acids (VFAs) and CH(4) were emitted during the drying process. It was found that the NH(3) and CO(2) were the primary compound released from the MSS drying process. In the case of the PMS, the VFAs and CO(2) were the main compounds released. The temperature and water content of sludge had great effects on the emission rates of NH(3), C(7)H(16), CO(2) and VFAs. The pH and chemical oxygen demand (COD) of condensate from the paddle dryer were also studied. It showed that pH and COD of condensate from MSS were much higher than that from the PMS, and that the higher COD value of the MSS condensate interrelated to the higher ammonium and sulfur content of it.

[Study on the optical properties of flame soot in the terahertz spectra domain].

Flame soot is an import product as a result of incomplete combustion of hydrocarbon fuels, and has important effect on the generation of some pollutant. The optical properties of the soot are the base for the optical combustion diagnostics. Terahertz time-domain spectroscopy technique was used to study the optical properties of the soot within 0.2-1.6 THz and the frequency-domain spectra were obtained through Fourier transform. The complex refractive index of the soot was deduced by the fixed-point iteration. The comparison of the complex refractive index between terahertz spectra domain and thermal radiation spectra domain was conducted and two methods of extracting the parameters were also compared. The results indicated that the soot has strong absorption in the studied spectra and the difference in the refractive index between the two spectra domains was not obvious, but the absorptive index variation in the thermal radiation spectra domain was larger. The difference between the two parameter extraction methods was not significant. The deduced results can provide the optical data of soot for the application of terahertz time-domain spectroscopy technique to the optical combustion diagnostics, and extend the optical combustion diagnostics application area.

[Ammonia gas concentration and velocity measurement using tunable diode laser absorption spectroscopy and optical signal cross-correlation method].

Simultaneous online measurement of gas concentration and velocity can be realized by tunable diode laser absorption spectroscopy (TDLAS) technique and optical signal cross-correlation method. The fundamental and relative factors of gas concentration and velocity measurement are described in the present paper. The spectral lines of NH3 used for gas sensing at communication band in near infrared range were selected and analyzed by the calculation based on the HITRAN database. In the verification experiment, NH3 and N2 were mixed by two mass flow meters and sent to flow through the quartz tube 0. 016 m in inner diameter and 1 m in length at normal temperature and pressure. The spectral line located at 6,548.7 cm(-1) was scanned at high frequency by the diode laser of 15 MHz linewidth and 1 cm' tunable range with no mode hoppings. The instantaneous NH3 absorbance was obtained using direct absorption method and the gas concentration was calculated. At the same time, the non-intrusive optical absorption signal cross-correlation method was utilized to obtain two concentration signals from two adjacent detectors mounted along the gas tube. The corresponding transit time of gas passing through the detectors was calculated by cross-correlation algorithm, and the average gas velocity was inferred according to the distance between the two detectors and the transit time. The relative errors were less than 7% for the gas concentration measurement, and less than 10% for the gas velocity measurement. Experimental results were proved to be of high precision and good repeatability in the lab. The feature of fast response and capacity immune to the in situ disturbance would lead to a potential in industry application for the real time measurement and control of gas pollutant emission in the future.

Source identification of PCDD/Fs in agricultural soils near to a Chinese MSWI plant through isomer-specific data analysis.

Isomer-specific data were investigated in order to identify the sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in agricultural soils, including Fluvo-aquic and paddy soils, in the vicinity of a Chinese municipal solid waste incineration (MSWI) plant. Homologue and isomer profiles of PCDD/Fs in soils were compared with those of potential sources, including combustion sources, i.e., MSWI flue gas and fly ash; and the impurities in agrochemicals, such as the pentachlorophenol (PCP), sodium pentachlorophenate (PCP-Na) and 1,3,5-trichloro-2-(4-nitrophenoxy) benzene (CNP). The results showed that the PCDD/F isomer profiles of combustion sources and agricultural soils were very similar, especially for PCDFs, although their homologue profiles varied, indicating that all the isomers within each homologue behave identically in the air and soil. Moreover, factor analysis of the isomer compositions among 33 soil samples revealed that the contamination of PCDD/Fs in agricultural soils near the MSWI plant were primarily influenced by the combustion sources, followed by the PCP/PCP-Na and CNP sources. This implication is consistent with our previous findings based on chemometric analysis of homologue profiles of soil and flue gas samples, and identifies PCP/PCP-Na as an additional important source of PCDD/Fs in the local area. This makes the similarities and differences of isomer profiles between Fluvo-aquic and paddy soils more explainable. It is, therefore, advisable to use isomer-specific data for PCDD/F source identifications where possible.

[Measurement on gas temperature distribution by tunable diode laser absorption spectroscopy].

The technique of tunable diode laser absorption spectroscopy (TDLAS) can be used for gas temperature distribution measurement by scanning multiple gas absorption lines with a tunable diode laser. The fundamental of gas temperature distribution measurement by TDLAS is introduced in the present paper, and the discretization strategy of equation for gas absorption is also given here. Using constrained linear least-square fitting method, the gas temperature distribution can be calculated with the help of physical constraints under the condition of uniform gas concentration and pressure. Based on the spectral parameters of four CO absorption lines near 6330 cm(-1) from HITRAN database, the model of two-temperature distribution at 300 and 600 K with each path length of 55 cm was set up. The effects of relative measurement error and different path length constraints of temperature bins on the gas temperature distribution measurement results were simulated by constrained linear least-square fitting. The results show that the temperature distribution calculation error increases as the relative measurement error rises. A measurement error of 5% could lead to a maximum relative error of 11%, and an average relative error of 2.2% for calculation result. And the weak physical constraints of path length for temperature bins could increase the calculation result error during the process of constrained linear least-square fitting. By setting up the model of two-temperature distribution with gas cells at room temperature as the cold section and in tube furnace as the hot section, the experiment of gas temperature distribution measurement in lab was carried out. Using four absorption lines of CO near 6330 cm(-1) scanned by VCSEL diode laser, and fitting the background laser intensity without absorption by the cubic polynomial to get the baseline signal, the integrals of spectral absorbance for gas temperature distribution measurement can be calculated. The relative calculation errors of path length for temperature bins are about 7.3%, 6.5%, 4.7% and 2.7% in the four cases.

[Temperature measurement of DC argon plasma jet].

The electron temperature of DC arc plasma jet is an important parameter, which determines the characteristics of plasma jet. The measurement of emission spectrum was performed to obtain the spectral intensities of some Ar lines and the method of diagrammatic view of Boltzmann was adopted to calculate the electron temperature. The results indicated that the electron temperature dropped at different speed along with the axes of the plasma jet and rose rapidly when the current was increased, and it also rose when the flowrate of argon was increased.

[Emission spectroscopy diagnosis of the radicals generated in gas-liquid phases gliding arc discharge].

Gas-liquid phases gliding arc discharge has been investigated as a potential treatment technology for liquid phase pollution treatment. To further understand the interaction mechanisms of gas-liquid phase gliding arc degradation process for the wastewater treatment, the characteristics of major reactive species (the OH and NO radicals) in a gas-liquid gliding arc at atmospheric pressure have been investigated by using optical emission spectroscopy. The chemical reactions that may lead to the generation of free radicals in the discharge were discussed. The influence of operating conditions (water feed rate, input voltage etc. ) on the relative intensity of radical emission was studied. The results show that axial evolution of the relative emission intensity of both reactive species exhibit the similar tendency under the same operating conditions. In non-thermodynamic equilibrium region of the arc discharge, the intensities of both radicals increase with the input voltage. In addition, the intensity of OH radical increases with the water feed rate, while the opposition phenomena are observed for NO radical.

Assessment of winter air pollution episodes using long-range transport modeling in Hangzhou, China, during World Internet Conference, 2015.

A winter air pollution episode was observed in Hangzhou, South China, during the Second World Internet Conference, 2015. To study the pollution characteristics and underlying causes, the Weather Research and Forecasting with Chemistry model was used to simulate the spatial and temporal evolution of the pollution episode from December 8 to 19, 2015. In addition to scenario simulations, analysis of the atmospheric trajectory and synoptic weather conditions were also performed. The results demonstrated that control measures implemented during the week preceding the conference reduced the fine particulate matter (PM2.5) pollution level to some extent, with a decline in the total PM2.5 concentration in Hangzhou of 15% (7%-25% daily). Pollutant long-range transport, which occurred due to a southward intrusion of strong cold air driven by the Siberia High, led to severe pollution in Hangzhou on December 15, 2015, accounting for 85% of the PM2.5 concentration. This study provides new insights into the challenge of winter pollution prevention in Hangzhou. For adequate pollution prevention, more regional collaborations should be fostered when creating policies for northern China.

Effects of inorganic chlorine source on dioxin formation using fly ash from a fluidized bed incinerator.

Chlorine source is indispensable for polychlorinated dibenzo-p-dioxin and furan (PCDD/F) formation during municipal solid waste (MSW) incineration. Inorganic chlorine compounds were employed in this study to investigate their effects on PCDD/F formation through heterogeneous synthesis on fly ash surfaces. A fly ash sample obtained from a fluidized bed incinerator was sieved to different size fractions which served as the PCDD/F formation sources. The capability of different metal chlorides which facilitate the formation of PCDDs/Fs was found to follow the trends: Na < Mg < K < Al < Ca, when two particle fractions of >177 miocrom and 104-125 microm were used in the experiments. However, the capability of NaCl, MgCl2 and KCl did not seem much different from each other, whereas CaCl2 and AlCl3 were much more active in PCDD/F formation. NaCl and MgCl2 were relatively effective to produce more PCDDs, while KCl, AlCl3 and CaCl2 generated more PCDFs during heterogeneous reactions occurring on fly ash. 2,3,7,8-TCDF was the most significant contributor to the toxicity of the PCDDs/Fs formed from inorganic chlorine sources. Decreasing the sizes of fly ash particles led to more active formation of PCDDs/Fs when NaCl was used as inorganic chlorine in the experiment. The highest PCDDs/Fs produced from particles with size <37 microm, while the lowest PCDDs/Fs produced from particles with size >177 microm. The toxicity generally increased with decreasing size of the fly ash particles. The formation of PCDDs was mainly facilitated by the two size fractions, 104-125 microm and <37 microm, while the formation of PCDFs was favored by the two other size fractions, >177 microm and 53-104 microm.

Laboratory-scale study of the suppression of PCDD/F emission during coal and MSW co-incineration.

The experimental test of co-incinerating Chinese raw municipal solid waste (MSW) and coal in a laboratory-scale tubular reactor was first reported in present study, and the emission of normal gas components and the effects of the S/C1 molar ratio or coal mixing percentages on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/Fs) emission were investigated and discussed. The results indicated that OCDD was the only PCDD homologues since others like TCDD-HpCDD was hardly detected, while as the categories of PCDF homologues were comparatively much more general. The amount of PCDD was much larger than that of PCDF in all operating conditions. Since sigma PCDF/sigma PCDD<<1, the dominant role of the precursor formation was proven in our experimental conductions. With increasing the coal addition to MSW (from 0 to 16%), PCDD and PCDF were reduced considerably. Coal and MSW may suppress the PCDD/F emissions efficiently (over 95%) during the MSW incineration process. The PCDD/F suppression results of the present study could be helpful guidance to the industrial application of Chinese MSW and auxiliary coal co-incineration processes. The PCDD/F stack emission data of two industrial incinerators using co-incineration technology in China seem to have a great positive reduction of PCDDs/Fs.