結合化學氧化沈澱與流化結晶床處理煙氣脫硫廢水中硼的應用: 影響因子研究

Combining chemical oxygen precipitation and fluidized crystallization bed for treatment of boron in flue gas desulfurization wastewater: Investigation of the influencing factors

吳漢釗(Hanzer Wu)

指導教授 ： 李奇旺

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2021年)

https://doi.org/10.6846/TKU.2021.00217

摘要

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。

關鍵字

流體化結晶床 ； 硼 ； 化學氧化沉澱 ； 鋇 ； 鈣 ； 煙氣脫硫廢水

並列摘要

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.

並列關鍵字

Fluidized-crystallization bed ； Boron ； Chemical oxo-precipitation ； Barium ； Calcium ； Wastewater of flue-gas desulfurization

參考文獻

[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.