วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

Efficiency of Mercury Removal in Packed-Bed Wet from Infectious Waste Incinerator

Amornpon Changsuphan*, Somrat Kerdsuwan**, Vladimir N. Bashkin*

Abstract environment, causing high risk of disease transmission and hence a myriad of health related problems, In the combustion process of infectious waste including such ailments as hepatitis, respiratory and highly quantities of mercury and its parasitic diseases, or even Aides [1]. The department compounds occur in the combustion product during of Public Hygiene, Ministry of Public Health, which the incineration. A large number of different mercury oversees the disposal of infectious waste from compound can be formed and decomposed again due hospitals under the Ministry’s jurisdiction, has to the continuity charging composition of the flue gas. developed standard incinerator designs of 25, 50, and The packed-bed wet scrubber is recommended for 100 - 150 kg/hr capacities. These designs have been improving removal efficiency. The feed wastes for the distributed to the Hospitals so that they may undertake test experiments are composed of simulated waste to commission and manage their own infectious waste including plastic, cotton, rubber gloves and 1,000 ppb incineration facilities. Most of these incinerators have pure mercury per batch (5 kg of simulated wastes per now either depreciated or impaired, prompting the batch). Mercury is fed to the incinerator every 6-10 Department of Public Hygiene to start importing min., at optimum operating temperature and incinerators to replace the old ones. However, under combustion air during the incineration. Mass balance the present economic climate, there are the second between mercury feed rate and mercury emission to thought about this alternative. For the first alternative, the stack is used to determined the mercury removal The Control Department Ministry of Natural efficiency. Three oxidizing agents are selected as a Resources and Evironment under the consultant of capture substance for mercury removal. The three The Waste Incineration Research Center (WIRC) of oxidizing agents are potassium permanganate, the King Mongkut’s Institute of Technology North hydrochloric acid and chlorine. When adding 15, 50 Bangkok has stepped in to play a part in the and 75 ppm of potassium permanganate, one found acquisition of appropriate technologies for the above that the mercury removal efficiencies are 79, 90 and purpose. It has initiated a project for the research and 99% respectively. Hydrochloric acid is added to development of indigenous infectious waste recirculation tank which reduces a pH to 5.0, 4.0 and incinerators. The project aims to import substitution 3.0. The results show approximately 70 % removal and possibly export of the incinerators and to reduce efficiency of mercury. Finally chlorine is selected for trade deficit.[2] mercury capture substance. It is added to recirculation One of the most importance problems of tank at three concentrations; 50, 75 and 100 ppm. The infectious waste incinerators is the control of heavy results show the removal efficiencies of 75, 80 and metals, especially mercury. Highly varying quantities 87% respectively. One found that 75 ppm of of mercury and its compounds occur in the potassium permanganate is more appropriate combustion products during the incineration. A large substance for mercury removal in packed-bed wet number of different mercury compounds can be scrubber than hydrochloric acid and chlorine. The formed and decomposed due to the continuously removal efficiency of the other major air pollutants changing composition of the flue gas and the (CO, NOX and SO2) are not different when compared increasing and decreasing temperature during the with adding and non adding a capture substance. combustion process. The transformation processes of heavy metals during waste incineration begin with the Keywords: Efficiency of mercury removal, infectious volatilization of solid or liquid heavy metals, followed waste incinerator, packed-bed wet by reaction with other elements to form volatile scrubber, mercury mass balance. compound, which are easily released out of the incineration system, mercury particulate and vapors that released from incinerator are captured by scrubber 1. INTRODUCTION [3, 4, 5, 6, 7, 8]. The objective of this study is to select The infectious wastes are those unwanted and some chemical substance to improve efficiency of Hg discard matter originating from healthcare premises. It removal in scrubber. is generally recognized that infectious waste has been mixed with municipal wastes and discharged to the

* The Joint Graduate School of Energy and Environment, King Mongkut’s University Technology Thonburi. ** The Waste Incineration Research Center, Department of Mechanical Engineering, Faculty of Engineering, King Mongkut’s Institute of Technology North Bangkok. Email : [email protected] วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

2.MATERIALS AND METHODS feeding system and a packed-bed wet scrubber. This incinerator can burn about 50 kilograms of infectious 2.1 Location waste per hour. Figure 1 shows the infectious waste This research studied at incinerator of incineration system. Sampran Hospital, a community hospital, located at control system for infectious the Sampran District, Nakornpatom Province, and is incinerator is a packed-bed wet scrubber. The wet under the jurisdiction of Ministry of Public Health. scrubber is used for collecting particulate matter as The hospital has 60 beds and has planned to 120 beds. well as for HCl and SO2. Scrubber is made of stainless The average number of patients is about 5,878 plate of 3 mm. thickness in cylinder shape with patients/month. The average number of admitted-in diameter of 0.8 m. Inside the tower is fill with ceramic patients is 515 patients/month. The average ratio of media and install with solution spray system. Solution admitted-in patients is 93.11% to the maximum spray system includes water pump unit for quencher capacity/month. tower and scrubber tower 2 units per tower. The piping is connect from pumps to each tower and spray 2.2 Incinerator the liquid via nozzle. The solution which is used in the The controlled-air incinerator is designed by quencher tower and scrubber is pumped from the the Waste Incineration Research Center (WIRC) of the recirculation tank. The injected liquid at the lower King Mongkut’s Institute of technology North sump of each chamber is collected and transmitted to Bangkok under the project of Research & recirculation tank. Mist Eliminator is made of stainless Development of Infectious Waste Incinerator which steel plate and placed in the net shape, used to was funding by the Pollution Control Department, eliminate some mists from exhaust gas before ejected Ministry of Natural Resources and Environment. The to atmosphere. working principle of this prototype infectious waste The Hg removal agent was fed into the incinerator is an intermittent controlled-air. It consists recirculation tank and pump to the spray system of the of two combustion chambers with an automatic quencher and scrubber unit.

Figure 1 The infectious Waste Incineration System

2.3 Simulated waste moisture content of 21.50%. The chemical The major physical components of infectious composition analysis of mercury concentration is 1.43 waste are cotton and gauze (67.15%), syringe mg/kg of waste. The simulated infectious waste is (13.48%), and rubber gloves (12.52%) (dry basis) and modeled from major physical components only วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

because it will influences more effects to combustion 2.5.3 Determination of the mercury from solution behavior than the minor component, so the simulated in packed-bed wet scrubber infectious waste includes of moisture contents (22%), Mercury from a solution in scrubber is Cotton (57%), Syringe (11%), Rubber (10%) and adds measured before and after incineration by using Hg of 1 mg/kg of simulated infectious waste. US.EPA Method 7470A [19]. This method is a cold vapor atomic absorption procedure approved for 2.4 Experimental Designed determining the concentration of mercury in mobility The experiment is designed to compare the procedure extracts, aqueous wastes and ground waters. efficiency of mercury removal in a packed-bed wet scrubber with and without adding any capture 2.5.4 Determination of the other major air substances under simulated waste incineration pollutant. condition. The capture substances that are selected for TESTO 350 flue gas analyzer is used to feed in the wet-scrubber include potassium measure combustion gases; Sulfur dioxide (SO2), permanganate, hydrochlorice acid and chlorine at vary Oxide of nitrogen (NOX), and Carbon monoxide (CO) concentrations. The incinerator is operated at optimum before and after packed-bed wet scrubber. The gas operating conditions , for example, the preheating analyzer is an electrochemical cell type. temperature on primary combustion chamber is 700 0C and secondary chamber is 900 0C. The waste is fed in 2.5.5 The efficiency of mercury removal each of 5 min/batch. Each batch contains of 5 The removal efficiency (RE) of hazardous kilograms of simulated waste. mercury constituent in the waste feed is calculated from the following equation [11]; 2.5 Methodology RE = []()W −W W ×100% 2.5.1 Determination of the particulate and gaseous in out in mercury emission. A multiple metal sampling train is used for Where: Win = mass of mercury in the waste stream fed into the packed- bed wet scrubber. stack sampling. Following the procedure in the US. EPA. Method 101A [18], the particulate and gaseous Wout = mass of mercury in the stack prior mercury emissions are withdrawn isokinetically and released to the atmosphere. collected by acidic potassium permanganate. 3. RESULTS AND DISCUSSION 2.5.2 Determination of the mercury from bottom 3.1 Mercury removal efficiency by packed-bed wet ash and infectious waste. A bottom ash is collected and analyzed scrubber without adding any capture substance. following the procedure in the US. EPA Method The results show that 0.936 mg/kg (approximately 90 %) of mercury is emitted from 7471B [20]. This method is approved for measuring total mercury (organic and inorganic) in soil, simulated waste to the primary and secondary sediments, bottom deposits, and sludge-type materials. chamber. Only 0.149 mg/kg (approximately 10%) remains in the bottom ash. After passing the wet It is a cold vapor atomic absorption method and is based on the absorption of radiation at the 253.7 nm. scrubber, mercury emitts to the environment at 0.513 wavelength by mercury vapor. mg/kg (approximately 50 %). Mercury mass balance shows in figure 2. These results show that the efficiency of mercury removal is 49.15%. It is quite low efficiency.

Mercury feed (1 mg/kg) Before Scrubber (0.936 mg/kg) After Scrubber (0.513 mg/kg)

Bottom Ash 0.149 mg/kg water 0.399 mg/kg (lose +0.085 mg/kg) (lose -0.024 mg/kg)

Figure 2 Mercury mass balance without adding any capture substance.

3 วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

3.2 Mercury removal efficiency by packed-bed wet (approximately 10%) of mercury remains in the scrubber with adding potassium permanganate. bottom ash , 0.901 mg/kg (approximately 90%) Potassium permanganate is added to the remains in the flue gas after secondary burning and recirculation tank before incineration at 15, 50 and 75 0.190 mg/kg (approximately 20%) emits from the ppm. Potassium permanganate is a strong oxidizing stack to the environment. Table 1 shows mercury agent with low corrosive properties, easy to buy and mass balance. Thus the efficiency of mercury removal inexpensive. When 15 ppm potassium permanganate 18 78.91%. is added, the results show that 0.075 mg/kg

Table 1.The efficiency of mercury removal in packed-bed wet scrubber from infectious waste incinerator with KMnO4 . KMnO4 Waste Hg Before Hg After Water Supply Bottom Efficiency Feed Wet scrubber Wet scrubber After Ash % ppm Mg/kg mg/kg mg/kg Mg/kg mg/kg 15 1 0.901 0.190 0.710 0.075 78.91 50 1 0.875 0.091 0.712 0.097 89.60 75 1 0.905 0.0081 0.786 0.083 99.10

For 50 ppm of potassium permanganate, By using potassium permanganate as a 0.875 mg/kg (approximately 90%) of mercury remains capture substance, a fraction of mercury is oxidized in the flue gas before wet scrubber. Only 0.097 mg/kg but the details of the reaction in packed-bed wet (approximately 10%) remains in the bottom ash, while scrubber are not well understood, especially with 0.091 mg/kg (approximately 10%) emits to the stack. regard to a part of the system in which the reaction The efficiency of mercury removal in packed-bed wet mainly takes place. A wet scrubbing system is a very scrubber is 89.60 % (see Table 1). complex liquid/gas phase reaction system which is not In the case of 75 ppm potassium in equilibrium [8]. Since the optimum concentration of permanganate, 0.905 mg/kg (approximately 90 %) is potassium permanganate for mercury removal can not in the flue gas occurring before entering the wet calculate, the results indicate that 75 ppm potassium scrubber and 0.083 mg/kg (approximately 10%) permanganate is a optimum condition for removal 1 remains in the bottom ash. Only 0.0081 mg/kg mg/kg of mercury under experimental conditions. (approximately 1%) emits to the air. Table 1 shows 99.10% of the efficiency of mercury removal. 3.3 Mercury removal efficiency by packed-bed wet Figure 3 shows that high concentration of scrubber with adding hydrochloric acid. potassium permanganate increases the efficiency of Hydrochloric acid is added to the mercury removal in packed-bed wet scrubber in the recirculation tank for adjusting the pH of water in the infectious waste incinerator. The highest efficiency of tank to 5.0, 4.0 and 3.0. A study recommends sulfuric mercury removal (99.10%) occurs when one added 75 acid as a capture substance for mercury removal in ppm of potassium permanganate. packed-bed wet scrubber but sulfuric acid has a strong corrosive property. In addition, sulfuric acid is not 100 appropriate substance for the prototype controlled air incinerator with packed-bed wet scrubber because this prototype is not designed for strong acidic condition. 90 The other alternative is hydrochloric acid since it is less corrosive than sulfuric acid. Moreover, 80 hydrochloric acid is not expensive. At pH 5.0, 0.873 mg/kg (approximately 90 %) of mercury is in the flue gas before entering to the 70 wet scrubber and 0.087 mg/kg (approximately 10%)

Removal Efficiency(% remains in the bottom ash. 0.245 mg/kg 60 (approximately 25%) emitts to the air. Table 2 shows 71.93% of the mercury removal efficiency and mercury mass balance. 50 0 20406080 KMnO4 Concentration (ppm) Figure 3 Efficiency of mercury removal by adding of KmnO4 วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

Table 2.The efficiency of mercury removal in packed-bed wet scrubber from infectious waste incinerator with Hydrochloric acid.

HCl Waste Hg Before Hg After Water Supply Bottom Efficiency feed Wet scrubber Wet scrubber After Ash % pH mg/kg mg/kg mg/kg mg/kg mg/kg 5.0 1 0.873 0.245 0.594 0.087 71.93 4.0 1 0.962 0.283 0.650 0.034 70.58 3.0 1 0.944 0.318 0.557 0.048 70.00

When pH of recirculating water is 4.0, 0.962 3.4 Mercury removal efficiency by packed-bed wet mg/kg (approximately 95 % ) passes to the wet scrubber with adding chlorine. scrubber and 0.034 mg/kg ( approximately 5 % ) Three concentrations of chlorine solution (50, remains in the bottom ash. Only 0.283 mg/kg 75 and 100 ppm) are added in recirculation tank. (approximately 30 %) emitts to the environment. In Chlorine is a strong oxidizing agent, easy to find and the case of pH 3.0, the result shows that mercury cheap (0.5 $US per kilogram). before wet scrubber is 0.944 mg/kg (approximately When adding 50 ppm of chlorine, 0.872 90%) while 0.048 mg/kg (approximately 5 %) mg/kg (approximately 90 %) is in the flue gas before remained in the bottom ash and 0.318 (approximately wet scrubber and 0.094 mg/kg (approximately 10%) 30 %) emits to the air. Figure 4. shows that lower pH remains in the bottom ash. Finally, 0.216 mg/kg of water recirculation tank does not improve the (approximately 20%) emits to the air. The efficiency efficiency of mercury removal in packed-bed wet of mercury removal in packed-bed wet scrubber is scrubber. The average efficiency of mercury removal 75.23 % (Table 3). is around 70 %. The pH could not lower than 3.0 In the case of 75 ppm chlorine, 0.890 mg/kg because this incinerator is not designed for acidic of mercury(approximately 90%) is in the flue gas condition. Acidic condition can damage pipe line and before entering to wet scrubber. Only 0.080 mg/kg pump in wet scrubber, while some study recommends (approximately 10%) remains in the bottom ash and pH lower than 3.0. If they can reduce the pH lower 0.173 mg/kg (approximately 20%) emits to the than 3.0 [10], it may be possible to make a higher environment and makes the efficiency of mercury efficiency. removal in packed-bed wet scrubber 80.56%.

100 For 100 ppm of chlorine, 0.916 mg/kg 95 (approximately 90%) is in the flue gas before wet scrubber and 0.075 mg/kg (approximately 10%) 90 remains in the bottom ash. Only 0.122 mg/kg 85 (approximately 10%) emits to the environment and the 80 efficiency of mercury removal is 86.72%. 75 Figure 5. shows that the concentration of 70 chlorine increases the efficiency of mercury removal 65 in packed-bed wet scrubber. The highest efficiency of

Removal Efficiency (% mercury removal (86.72%) occurs when adding 100 60 ppm of chlorine. In this case, one can suggest that 55 chlorine concentration couldn’t increase more than 50 100 ppm because the recirculation tank is a open air 2 2.5 3 3.5 4 4.5 5 5.5 system, chlorine has a strong smell and strong HCl (pH) oxidizing agent has an effect on human health. Figure 4 Efficiency of mercury removal by adding of Hydrochloric acid. วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

Table 3.The efficiency of mercury removal in packed-bed wet scrubber from infectious waste incinerator with Chlorine.

Cl2 Waste Hg Before Hg After Water Supply Bottom Efficiency feed Wet scrubber Wet scrubber After Ash % ppm mg/kg mg/kg mg/kg mg/kg mg/kg 50 1 0.872 0.216 0.582 0.094 75.23 75 1 0.890 0.173 0.667 0.080 80.56 100 1 0.916 0.122 0.688 0.075 86.72

100 When hydrochloric acid is added as a capture substance, the results are not different from without

90 that any capture substance. Figure 7 shows carbon

% monoxide and oxide of nitrogen remove 40% by packed-bed wet scrubber and for sulfur dioxide the 80 efficiency is nearly 100%.

70

 

Removal Efficiency(  

100 

60

 

% 80  none



50 60       pH= 5

50 60 70 80 90 100

   

Cl2 Concentration (ppm) 40  pH= 4

  

Figure 5 Efficiency of mercury removal by adding of 20 

Removal Efficiency ( pH= 3

   Chlorine. 0  3.5 Effects on others major air pollutants CO NOx SO2

Other major air pollutants ( CO, NOX and Figure 7 Removal Efficiency in case of adding HCl SO2) are measured during the determination of the efficiency of mercury removal. When using chlorine as a capture substance, In the case of using potassium permanganate Carbon monoxide and oxide of nitrogen are remove as a capture substance, the packed-bed wet scrubber 50% by packed-bed wet scrubber and for sulfur captures carbon monoxide and oxide of nitrogen about dioxide the efficiency is nearest 100%. The results are 40%. For Sulfur dioxide, wet scrubber captures not different compare with adding a capture substance nearest 100% (Figure 6). The results show no (Figure 8). difference when compared with non-using a capture

substance.



100     

    

100 % 80  none

%     

80 none 60  50 ppm

      

60 15 ppm            40  75 ppm

           

40 50 ppm  100 ppm

Removal Efficiency ( 20

         

20 75 ppm 

Removal Efficiency (       0 0 CO NOx SO2 CO NOx SO2 Figure 8 Removal Efficiency in case of adding Cl Figure 6 Removal Efficiency in case of adding 2 KmnO4 วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

3.6 Hg removal in waste water treatment system leaches with organic materials. For this results, one could not calculate the optimum concentration of the In packed-bed wet scrubber system, mercury capture substance for mercury removal in packed-bed was captured from the gas phase to the liquid phase. wet scrubber. The further study is required to So the water after the rejected by packed-bed wet determined the mercury removal efficiency at the scrubber system must be treated by waste water higher concentration of mercury and investigate treatment system. The coagulation with ferric sulfate reaction of the capture substance for mercury removal. or alum, and filtration with activated carbon were recommended for mercury removal in waste water 5. ACKNOWLEDGEMENT treatment system. The authors would like to express their 4. CONCLUSION grateful to the Joint Graduate School of Energy and Environment for their funding support and the Waste By considering the efficiency of mercury Incineration Research Center, Department of removal in packed-bed wet scrubber of a prototype Mechanical Engineering, Faculty of Engineering, controlled-air infectious waste incinerator, it is shown King Mongkut’s Institute of Technology North that the efficiency of mercury removal for 5 kg waste Bangkok for facility support so that this task can be feed rate and 1 mg/kg of mercury is highest (99.10%) successfully completed. at 75 ppm of potassium permanganate. Potassium permanganate is very cheap and easy to use. Under the experimental conditions, potassium permanganate is an appropriate substance for mercury removal in References packed-bed wet scrubber. The average efficiency is in the range of 70% [1] Kerdsuwan S., “Case Study of Using Hospital for hydrochloric acid. Vogg [8] recommends pH less Waste Incinerator in Thailand”, 93rd Annual than 3.0 to make a high efficiency of mercury Conference of Air&Waste Management removal, but this prototype controlled-air infectious Association, Salt Lake City, USA, June, 2000. waste incinerator is not designed for the acidic [2] Kerdsuwan S, “Design of 50kg/hr Controlled-Air solution. The maximum efficiency of chlorine at Hospital Waste Incinerator”, Proceeding of 93 rd concentration 100 ppm is 86.72%. Vogg [8] also Annual Conference of Air &Waste Management recommends the concentration of Cl2 more than 100 Association (2000) , Salt lake City, USA. ppm, but in this case the chlorine concentration could [3] Adrian Pluss and Ray E. Ferrell, JR.(1991). not increase more than 100 ppm because the “Characterization of Lead and Other Heavy recirculation tank is an open air system and chlorine Metals in Fly Ash from Municipal Waste has a strong smelt and strong oxidizing agent that has Incinerators.” Hazardous Waste and Hazardous an effect on human health. Materials. 8:275-292. To compare other major air pollutants [4] A.J Chandler, T. T. Eighmy, J. Hartlen, O. between non adding and adding a capture substance. Hjelmar, D.S. Kosson, S.E. Sawell, H.A. This results conclude that the capture substance has Vandersloot, J. Vehlow.(1997). Municipal Solid not an effect to the efficiency of the other air Waste Incinerator Residues. 974 p. pollutants removal. [5] Arun D. Shendrikar and D.S. Ensor.(1986). In combustion process all mercury “Measurement of Mercury Combustion Aerosols compounds are transformed to elemental mercury in Emission from Stationary Sources.” Waste since heating mercury compounds to temperatures Management and Research.4: 76-93. above 700 0C [13]. It is difficult to interpret that the [6] Chang-Ya Wu, Pratim Biswas, and Nicholas J. mechanism responsible for the reactions. Difficulties Fendinger.(1994). “Model to Assess Heavy are already encountered when a balance is to be Metal Emission from Municipal Solid Waste and established of mercury streams in the refuse Hazardous Materials.11: 71-92. incineration process [8]. They interpret this as a direct [7] Gray D. Hinshaw. (1994). “Behavior and Control sign that the reduction reaction actually occurs. Until of Metals in a Hazardous Waste Incinerator.” now, details of this reaction are not well understood. A Hazardous Waste and Hazardous Materials.(11): wet scrubbing system is a very complex liquid/gas 93-109. phase reaction system which is not equilibrium, with [8] H. Vogg, H. Braun, M. Metzger and J. Schneider. largely differing gas compositions and varying droplet (1986). “The Specific role of Cadmium and contents on the scrubber head compared to its outlet. Mercury in Municipal Solid Waste Incineration.” In addition, Ionic mercury, once present in water, is Waste Management and research. 4: 65-74. capable of forming a wide variety of complexes and วารสารวิชาการพระจอมเกลาพระนครเหนือ ปที่ 13 ฉบับที่ 4 ต.ค.-ธ.ค. 2546 The Journal of KMITNB., Vol.13, No.4, Oct - Dec 2003

[9] Jan G.T. Bergstrom.(1986). “Mercury Behavior [15] S. Cernuschi, M.Giugliano and I. de Paoli. in Flue Gases.” Waste Management and (1990). “Leaching of Residues from MSW Research. 4: 57-64. Incineration.” Waste Management and Research. [10] Jyh-Cherng Chen, Ming-Yen Wey, and Ming- 8: 419-427. Hong Yan.(1999)." The Effects of Chloride [16] Tay Joo Hwa.(1991). “Leachate of Fly Ash Additives on Adsorption of Heavy Metals Derived from Refuse Incineration. During Incineration.” J. Air and Waste “Environmental Mornitoring and Assessment.19: Management Association. 49:1116-1120. 157-164. [11] Louis Theodore.(1990). Air Pollution Control and [17] T.C. Ho, Hom-Ti Lee, T.H. Kuo, D. Chen, and Waste Incineration for Hospitals and Medical W.D. Bostick.(1994). “Analysis of Incinerator Facilities. 405 p, Van Nostrand Reinhold, New Performance and Metal Emissions from Recent York. Trial and Test Burns.” Hazardous Waste and [12] Ming-Yen Wey, Jeng-Long Su, and Jyh-Cherng Hazardous Materials. 11: 53-70. Chen.(1999). “Influence of Operating Conditions [18] United State. Environmental Protection Agency. on The Formation of Heavy Metal Compounds (2000). Determination of Particulate and During Incineration.” J. Air and Waste Gaseous Mercury Emissions from Stationary Management Association.49; 444-453. Source ( Method 101A). [13] Oliver Lindgvist.(1986). “Fluxes of Mercury in [19] United State.Environmental Protection Agency. The swedish environment: Contributions from (1994). Mercury in Liquid waste (method Waste Incineration.” Waste Management and 7470A). Research. 4: 35-44. [20] United State.Environmental Protection Agency. [14] Paul H. Brunner and Hermann Monch.(1986). “ (1998). Mercury in Solid or Semi-Solid Waste The Flux of Metals Through Municipal Solid (Method 7471B). Waste Incinerators.” Waste Management and [21] United State.Environmental Protection Agency. Research. 4: 105-119. (1992). Toxicity Characteristic Leaching Procedure (Method 1311).

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