本研究以流體化結晶床結合化學氧化沉澱程序，利用鋇或者鈣作為沉澱劑，去除煙氣脫硫廢水中的硼。利用雙氧水將硼氧化成過硼酸，利用鋇作為沉澱劑可以在pH為10.5的環境下將煙氣脫硫廢水中的硼從620 mg/L去除到10 mg/L以下。此外，通過處理合成廢水和來自火力發電廠的煙氣脫硫廢水，分析了煙氣脫硫廢水中影響對硼處理程序的影響因素。
使用鋇或者鈣作為沉澱劑處理含硼合成廢水的結果顯示，在硫酸鹽對硼的摩爾比為1或者以下的時候，使用鋇作為沉澱劑仍然能去除廢水中90%以上的硼，但隨著硫酸鹽的增多，對硼的去除效率也隨之受到影響，硫酸鹽對硼的摩爾比越大，去除效率則越低。在使用鈣作為沉澱劑時，在硫酸鹽對硼的摩爾比為1的時候，就僅僅只除去了廢水中40%的硼。在使用鋇處理來自火力發電廠的煙氣脫硫廢水的結果顯示，在硫酸鹽對硼的摩爾比小於1的時候，能正常去除廢水中的硼，當硫酸鹽對硼的摩爾比大於1的時候，可以通過使用過量的鋇來減少硫酸鹽的影響。在使用流體化結晶床處理煙氣脫硫廢水的時候，有大量的污泥產生，通過對污泥進行TCLP分析，得到污泥中的鋇濃度為13.8 mg/L，而台灣對固體廢棄物的鋇濃度管制值為100 mg/L。

In this study, a fluidized crystallization bed combined with a chemical oxo-precipit-ation process, using barium or calcium as a precipitant to remove boron in flue gas desulfurization wastewater. Using hydrogen peroxide to oxidize boron to perboric acid, barium can be used as a precipitant to remove boron in flue gas desulfurization wastewater from 620 mg/L to less than 10 mg/L in an environment with a pH of 10.5. In addition, through the treatment of synthetic wastewater and flue gas desulfurization wastewater from coal-fired power plants, the factors affecting the boron treatment process in flue gas desulfurization wastewater were explored.

The results of using barium or calcium as a precipitating agent to treat boron-containing synthetic wastewater show that when the molar ratio of sulfate to boron was 1 or less, using barium as a precipitant can still remove more than 90% of boron in the wastewater. However, with the increase of sulfate, the removal efficiency of boron was also affected. The greater the molar ratio of sulfate to boron, the lower the removal efficiency. When calcium was used as a precipitant, and the molar ratio of sulfate to boron was 1, only 40% of boron in the wastewater was removed. The results of using barium to treat flue gas desulfurization wastewater from coal-fired power plants show that when the molar ratio of sulfate to boron was less than 1, more than 98% the boron in the wastewater can be removed. When the molar ratio of sulfate to boron was greater than 1, the effect of sulfate on the boron removal efficiency can be reduced by using overdosed barium. When a fluidized crystallization bed was used to treat flue gas desulfurization wastewater, a large amount of sludge was produced. Through TCLP analysis of the sludge, the barium concentration in the sludge is 13.8 mg/L, which is less than the regulation limit of 100 mg/L in Taiwan.

Acknowledgements i
中文摘要 ii
Abstract iii
Contents v
List of Tables viii
List of Figures ix
1 Introduction 1
1.1 FGD wastewater 1
1.2 B removal 2
1.3 Problems 4
1.4 Objective 4
2 Literature reviews 6
2.1 FGD process and wastewater produced 6
2.1.1 Development of FGD 6
2.1.2 Boron in FGD 8
2.1.3 Wastewater of wet FGD 9
2.2 Chemical oxo-precipitation 10
2.3 Fluidized crystallization bed 13
2.3.1 Fluidized-bed homogeneous crystallizer (FBHC) 13
2.3.2 Using a fluidized-bed reactor to continuously remove heavy met als in FGD wastewater 16
2.4 Sulfate removal 17
2.4.1 Sulfate removal by precipitation  17
2.4.2 Sulfate removal by crystallization 19
3 Materials and Methods 20
3.1 Chemical 20
3.2 Experimental set up and procedures 22
3.2.1 Experimental set up 22
3.2.2 Experimental procedures 23
3.3 Analysis 24
4 Results and Discussion 26
4.1 Chemical equilibrium modeling of Ba/Ca/Sulfate/Boron interaction 26
4.2 Removing boron using barium as precipitant 30
4.2.1 Effects of sulfate on B removal and residual Ba for COP-FBC
process using barium as precipitant 30
4.2.2 Reduce residual barium by reducing Ba dosage 35
4.3 Removing boron using calcium as precipitant 37
4.3.1 Effects of sulfate on B removal and residual Ca for COP-FBC
process 37
4.4 Application of COP-FBC system in real wastewater from coal-fire power
plant 40
4.4.1 Treatment of high-concentration of FGD wastewater using COP FBC process 40
4.4.2 Treatment of chemical coagulation treated FGD wastewater 42
4.4.3 TCLP to characterize sludge collected from COP-FBC 44
5 Conclusions 46
References 47
1.1 Boron discharge limits of wastewater from FGD 3
2.1 Soluble constituents and pH reaction of the FGD wastewater [28] 10
2.2 Comparison of chemical precipitation and fluidized-bed reactor [35] 17
3.1 FGD wastewater quality collected from Ho-Ping coal-fired power plant on October 11, 2020 20
3.2 FGD wastewater quality collected from Ho-Ping coal-fired power plant on March 21, 2021 21
3.3 FGD wastewater from Ho-Ping coal-fired power plant treated by chemical coagulation using ferric salts 21
2.1 Schematic diagram of 1st generation of wet-Process Limestone/Lime Gypsum Flue Gas Desulfurization System [21] 7
2.2 Schematic diagram of 2nd generation of wet-Process Limestone/Lime Gypsum Flue Gas Desulfurization System [21] 7
2.3 Schematic diagram of 3rd generation of wet-Process Limestone/Lime Gypsum Flue Gas Desulfurization System [21] 8
2.4 Thermodynamic equilibrium of peroxo compounds and corresponding constants of boric acid, hydrogen peroxide, perborates and proton [17] 10
2.5 Effect of pretreatment pH on removal of boron by COP process (Initial boron concentration = 1000 mg/L, initial [H2O2]/[B] = 1.5, [Ba]/[B] = 0.6, pretreatment time = 20 min) [17] 12
2.6 Apparatus of fluidized-bed reactor for FBHC [10] 15
2.7 Schematic drawing of the fluid-bed pilot plant [35] 16
3.1 Schematic diagram of fluidized-bed reactor for FBC 23
4.1 The species distribution of Ca for solution with Ca and B molar ratio of 1:1 and initial Ca concentration of 0.01 M using the modeling software Mineql+. Temperature = 25°C 27
4.2 The species distribution of Ca for solution with Ca, B and sulfate molar ratio of 1:1:1 and initial Ca concentration of 0.01 M using the modeling software Mineql+. Temperature = 25°C 27
4.3 The species distribution of Ba for solution with Ba and B molar ratio of 1:0 and initial Ba concentration of 0.01 M using the modeling software Mineql+. Temperature = 25°C 28
4.4 The species distribution of Ba for solution with Ba ,B and sulfate molar ratio of 1 and initial Ba concentration of 0.01 M using the modeling software Mineql+. Temperature = 25°C 29
4.5 Effect of sulfate on Boron removal in fluidized-bed system using barium as precipitant (Initial [B] = 54 mg/L, [Ba]/[B] = 1, [H2O2]/[B] = 2, and pH = 10.5) 31
4.6 Boron removal efficiency VS. Sulfate/B molar ratio (Initial [B] = 54 mg/L, pH = 10.5 and at BV = 12) 32
4.7 Effect of sulfate on Boron removal in fluidized-bed system using barium as precipitant (Initial [B] = 54 mg/L, [SO224]/[B] = 2, [H2O2]/[B] = 2 and pH = 10.5) 33
4.8 Boron removal efficiency VS. Ba/B molar ratio (Initial [B] = 54 mg/L,[SO224]/[B] = 2, [H2O2]/[B] = 2, pH = 10.5 and at BV = 12) 34
4.9 Effects of Sulfate on Boron removal efficiency of COP process (Initial [B]= 54 mg/L, [Ba]/[B] = 1, [H2O2]/[B] = 2 and pH = 10.5) with sulfate being first removed with Ba at Ba/Sulfate = 1 35
4.10 Boron removal efficiency VS. Ba:B molar ratio (Initial [B] = 500 mg/L, without sulfate, [H2O2]/[B] = 2 and pH = 10.5) 36
4.11 Effect of sulfate on Boron removal in fluidized-bed system using calcium as precipitant (Initial [B] = 54 mg/L, [SO224]/[B] = 1, [H2O2]/[B] = 2 and pH = 10.5) 38
4.12 Boron removal efficiency VS. Sulfate/B molar ratio (Initial [B] = 54 mg/L, [SO224]/[B] = 1, [H2O2]/[B] = 2, pH = 10.5 and at BV = 12) 39
4.13 A comparison of the performance of barium and calcium in the COP FBC system (Initial [B] = 54 mg/L, [H2O2]/[B] = 2, and pH = 10.5) 40
4.14 Boron removal of wastewater from coal-fired power plant using COP FBC system. (Initial [B] = 620 mg/L, [Ba]/[B] = 1, [H2O2]/[B] = 2, pH= 10.5, and [SO224]/[B] = 0.5) 42
4.15 Boron removal of wastewater from coal-fired power plant using COP sys tem. (Initial [B] = 74 mg/L, [H2O2]/[B] = 2, pH = 10.5, and [SO224]/[B]= 2.5) 43
4.16 Removal efficiency of boron in COP process after removing sulfate first from wastewater of Ho-ping power plant wastewater with Ba/sulfate =1. (Initial [B] = 103.7 mg/L, [H2O2]/[B] = 2, pH = 10.5, and [SO224]/[B]= 2.5) 44

[1] P. L. Joskow, R. Schmalensee, and E. M. Bailey, (1998) “The Market for Sulfur
Dioxide Emissions” American Economic Review 88(4): 669–685. doi: 10.
2307/117000. [2] H. N. Soud. Developments in FGD. 29. IEA Coal Research London, 2000. doi:
EDB-00:044926. [3] W. Yi-wei, (2006) “Study on the wastewater treatment in limestone-gypsum wet
FGD process” Electric Power 4: 75–78. doi: 1673-0038201935-0227-02. [4] J. B. Lefers, W. F. van den Broeke, H. W. Venderbosch, J. de Niet, and A.
Kettelarij, (1987) “Heavy metal removal from waste water from wet lime(stone)-
gypsum flue gas desulfurization plants” Water Research 21(11): 1345–1354.
doi: 10.1016/0043-1354(87)90008-X. [5] M. Andalib, S. Arabi, P. Dold, and C. Bye, (2016) “Mathematical modeling
of biological selenium removal from flue gas desulfurization (FGD) wastewa ter treatment” WEFTEC 2016 - 89th Water Environment Federation
Annual Technical Exhibition and Conference: 228–248. doi: 10 . 2175 /193864716819706770. [6] F. D. Mooney and C. Murray-Gulde, (2008) “Constructed treatment wetlands
for flue gas desulfurization waters: Full-scale design, construction issues and
performance” Environmental Geosciences 15: 131–141. doi: 10.1306/eg.09200707011.
[7] M. R. Riffe, B. E. Heimbigner, and K. A. Braunstein, (2008) “Wastewater treat ment for FGD purge streams” Air and Waste Management Association
- 7th Power Plant Air Pollutant Control ’Mega’ Symposium 2008 2:
798–820. doi: 10.3155/2008CP175.33. [8] Y. Kang, J. Lu, and J. Guo, (2017) “Treatment of Wet FGD Wastewater by a
Modified Chemical Precipitation Method Using a Solid Powder Reagent” Trans actions of Tianjin University 23(2): 110–121. doi: 10.1007/s12209-017-
0027-4. [9] R. Ochoa-Gonz´alez, A. F. Cuesta, P. C´ordoba, M. D´ıaz-Somoano, O. Font, M. A.
L´opez-Ant´on, X. Querol, M. R. Mart´ınez-Tarazona, and A. Gim´enez, (2011)
“Study of boron behaviour in two spanish coal combustion power plants” Jour nal of Environmental Management 92(10): 2586–2589. doi: 10.1016/j.
jenvman.2011.05.028. [10] X. Vu, J. Y. Lin, Y. J. Shih, and Y. H. Huang, (2018) “Reclaiming Boron as Cal cium Perborate Pellets from Synthetic Wastewater by Integrating Chemical Oxo Precipitation within a Fluidized-Bed Crystallizer” ACS Sustainable Chem istry and Engineering 6(4): 4784–4792. doi: 10 . 1021 / acssuschemeng .
7b03951. [11] S. Bakirdere, S. Orenay, and M. Korkmaz, (2014) “Effect of Boron on Human
Health” The Open Mineral Processing Journal 3(1): 54–59. doi: 10.2174/
1874841401003010054. [12] V. C. Kok, P. R. Winn, Y.-J. Hsieh, J.-W. Chien, J.-M. Yang, and G.-P. Yeh,
(2019) “A pilot survey of potentially hazardous trace elements in the aquatic environment near a coastal coal-fired power plant in Taiwan” Environmental
health insights 13: 1178630219862236. doi: 10.1177/1178630219862236.
[13] L. Fang, X. Liu, H. Wu, and Z. Zhang, (2011) “Discharge control of boron in
inland nuclear power plant” Chinese Journal of Nuclear Science and En gineering 31(1): 86–92. doi: 0258-0918(2011)01-0086-07. [14] Y. Xu and J. Q. Jiang, (2008) “Technologies for boron removal” Industrial and
Engineering Chemistry Research 47(1): 16–24. doi: 10.1021/ie0708982. [15] Y. J. Shih, C. H. Liu, W. C. Lan, and Y. H. Huang, (2014) “A novel chemical oxo precipitation (COP) process for efficient remediation of boron wastewater at room
temperature” Chemosphere 111: 232–237. doi: 10 . 1016 / j . chemosphere .
2014.03.121. [16] C. K. Tsai, N. T. Lee, G. H. Huang, Y. Suzuki, and R. A. Doong, (2019) “Simulta neous Recovery of Display Panel Waste Glass and Wastewater Boron by Chem ical Oxo-precipitation with Fluidized-Bed Heterogeneous Crystallization” ACS
Omega 4(9): 14057–14066. doi: 10.1021/acsomega.9b01900. [17] J. Y. Lin, Y. J. Shih, P. Y. Chen, and Y. H. Huang, (2016) “Precipitation recovery
of boron from aqueous solution by chemical oxo-precipitation at room tempera ture” Applied Energy 164: 1052–1058. doi: 10.1016/j.apenergy.2014.12.
058. [18] J. Y. Lin, Y. J. Shih, T. Y. Hsieh, and Y. H. Huang, (2016) “Role of phase
transformation of barium perborates in the effective removal of boron from aque ous solution: Via chemical oxo-precipitation” RSC Advances 6(68): 63206–
63213. doi: 10.1039/c6ra11545d.
[19] S. Tait, W. P. Clarke, J. Keller, and D. J. Batstone, (2009) “Removal of sulfate
from high-strength wastewater by crystallisation” Water Research 43(3): 762–
772. doi: 10.1016/j.watres.2008.11.008. [20] C. T. Benatti, C. R. G. Tavares, and E. Lenzi, (2009) “Sulfate removal from
waste chemicals by precipitation” Journal of Environmental Management
90(1): 504–511. doi: 10.1016/j.jenvman.2007.12.006. [21] R. S. Ren, F. E. Shi, X. M. Huang, and D. H. Jiang, (2011) “Application of
additives to the wet flue gas desulfurization” 2011 International Conference
on Electric Technology and Civil Engineering, ICETCE 2011 - Pro ceedings: 1037–1040. doi: 10.1109/ICETCE.2011.5776280. [22] P. S. Nolan, K. E. Redinger, G. T. Amrhein, and G. A. Kudlac, (2004) “Demon stration of additive use for enhanced mercury emissions control in wet FGD
systems” Fuel Processing Technology 85(6-7): 587–600. doi: 10.1016/j.
fuproc.2003.11.009. [23] R. Jamil, L. Ming, I. Jamil, and and Rizwan Jamil, (2013) “Application and
Development Trend of Flue Gas Desulfurization (FGD) Process: A Review” In ternational Journal of Innovation and Applied Studies 4(2): 286–297.
doi: ISSN:2028-9324. [24] C. T. Chi and J. H. Lester, (1989) “Utilization of adipic acid byproducts for
energy recovery and enhancement of flue gas desulfurization” Environmental
Progress 8(4): 223–226. doi: 10.1002/ep.3300080413.
[25] D. J. Swaine, (1995) “The contents and some related aspects of trace elements
in coals” Environmental aspects of trace elements in coal: 5–23. doi:
10.1007/978-94-015-8496-8_2. [26] M. Pougnett and M. Orren, (1986) “The determination of boron by inductively
coupled plasma atomic emission Spectroscopy. Part 1: method Development” In ternational journal of environmental analytical chemistry 24(4): 253–
265. doi: 10.1016/S0016-2361(00)00035-1. [27] R. Meij, (1994) “Trace element behavior in coal-fired power plants” Fuel Pro cessing Technology 39(1-3): 199–217. doi: 10.1016/0378-3820(94)90180-5. [28] J. Kluczka, (2020) “Removal of boron and manganese ions from wet-flue gas
desulfurizationwastewater by hybrid chitosan-zirconium sorbent” Polymers 12(3):
doi: 10.3390/polym12030635. [29] Y. Magara, A. Tabata, M. Kohki, M. Kawasaki, and M. Hirose, (1998) “De velopment of boron reduction system for sea water desalination” Desalination
118(1-3): 25–33. doi: 10.1016/S0011-9164(98)00076-9. [30] Y. S. Sadovskii, T. Solomoichenko, T. Prokop’eva, Z. P. Piskunova, N. Razu mova, B. Panchenko, and A. Popov, (2012) “Reactivity of the H2O2/B(OH)3/HO
- system in the decomposition of 4-nitrophenyl esters of diethylphosphonic and di ethylphosphoric acids” Theoretical and Experimental Chemistry 48: 163–
171. doi: 10.1007/s11237-012-9256-8. [31] S. Rey and D. M. Davies, (2006) “Photochemistry of peroxoborates: Borate inhibi tion of the photodecomposition of hydrogen peroxide” Chemistry - A European
Journal 12(36): 9284–9288. doi: 10.1002/chem.200600437.
[32] S. Xing et al., (2011) “Study on Emission Limits for Barium in Industrial
Wastewater” Environmental Protection Science 4: doi: 10.16803/j.cnki.
issn.1004-6216.2011.04.004. [33] M. M. Bello, A. A. Abdul Raman, and M. Purushothaman, (2017) “Applications
of fluidized bed reactors in wastewater treatment – A review of the major design
and operational parameters” Journal of Cleaner Production 141: 1492–
1514. doi: 10.1016/j.jclepro.2016.09.148. [34] J. W. Morse, R. S. Arvidson, and A. L¨uttge, (2007) “Calcium carbonate for mation and dissolution” Chemical Reviews 107(2): 342–381. doi: 10.1021/
cr050358j. [35] P. B. Nielsen, T. C. Christensen, and M. Vendrup, (1997) “Continuous removal of
heavy metals from FGD wastewater in a fluidised bed without sludge generation”
Water Science and Technology 36(2-3): 391–397. doi: 10 . 1016 / S0273 -
1223(97)00413-7. [36] P. Lens, A. Visser, A. Janssen, L. Hulshoff Pol, and G. Lettinga, (1998) “Critical
Reviews in Environmental Science and Technology Biotechnological Treatment of
Sulfate-Rich Wastewaters Biotechnological Treatment of Sulfate-Rich Wastewa ters” Critical Reviews in Environmental Science and Technology 28(1):
41–88. doi: 10.1080/10643389891254160. [37] N. Drouiche, S. Aoudj, M. Hecini, N. Ghaffour, H. Lounici, and N. Mameri,
(2009) “Study on the treatment of photovoltaic wastewater using electrocoagu lation: Fluoride removal with aluminium electrodes-Characteristics of products”Journal of Hazardous Materials 169(1-3): 65–69. doi: 10.1016/j.jhazmat.
2009.03.073. [38] J. Zhang and S.-h. Zhang, (2007) “Sulfate radical removal by barium carbonate
method” China Chlor-Alkali 5: doi: 1004-9649(2006)04-0075-04. [39] T. Itakura, R. Sasai, and H. Itoh, (2005) “Precipitation recovery of boron from
wastewater by hydrothermal mineralization” Water Research 39(12): 2543–
2548. doi: 10.1016/j.watres.2005.04.035.