第二章 文獻回顧
2.6 三氯沙處理技術及瓶頸
三氯沙為目前許多個人護理用品中，較為廣泛使用的一種污染物，
可能對環境生態系統及人體健康造成長期威脅，除了傳統廢水處理系 統無法有效將其去除外，因其疏水性，於土壤及河川底泥亦經常被檢
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表 2.9 電動力技術對於有機污染土壤處理彙整-實驗尺度
Contaminants Experiment parameter Summary results Literature
Diesel
Electrode: Graphite (10.0 cm × 10.0 cm × 1.0 cm) Electrolyte: 30.36 mg/L of NaNO3 , 70 mg/L of
NaHCO3 and 88.75 mg/L of Na2SO4 (Flushing agent: 8.2 mM SDS)
Potential gradient: 1.5 V/cm (polarity reversal) EK cell size: 10 ×10 ×5 cm3 (methacrylate)
1. Initial concentration: 10000 mg/kg
2. 36% of the diesel was removed in the soil under 1.5 V/cm after 15 days
Mena et al., 2016
Diesel
Electrode: Graphite (10.0×10.0×1.0 cm3)
Electrolyte: 30.4 mg/L NaNO3; 70.0 mg/L NaHCO3; 88.7 mg/L Na2SO4 ; 2.4 g/L
SDS(catholyte) Potential gradient: 1 V/cm
EK cell size: 20 cm×10.0 cm×10.0 cm (methacrylate)
1. A surfactant was necessary to improve the contact between
microorganisms and diesel, and 29% of the diesel was removed from the soil in only 14 days.
2. High buffer concentration was required that caused a high current density, high conductivity, soil heating and nutrient removal by a high EOF. However, it was negatively affected the biological activity.
Ramírez et al.,2015
TPHs
Electrode: graphite electrodes (20 cm×10 cm× 1 cm) Potential gradient:1 V/cm
Reaction time: 10 days
EK cell size: 100 cm×100 cm×25 cm Initial concentration: 45000 mg/kg Electrode configuration: diagonal center
1. 48% removal efficiency of TPH was achieved around the electrodes, and the minimum was obtained at the diagonal center of four electrodes, implying a positive correlation between the degradation
efficiency and electric intensity.
2. No significant spatial shifts in microbial community composition and bacterial numbers were detected among different sampling positions.
Guo et al .;2014
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表 2.7 電動力技術對於有機污染土壤處理彙整-實驗尺度(續)
Contaminants Experiment parameter Summary results Literature
phthalate esters and acetaminophen
Electrode: Titanium rod
Electrolyte: Houjing River water
Potential gradient: 1 V/cm (polarity reversal) Reaction time: 28 days
EK cell: 6.5 cm in diameter and 21 cm in length.
(cylindrical compartments)
1. Injection of nano-schwertmannite slurry and H2O2 into the anode reservoir would yield ‧OH that transported by the electroosmotic flow and/or electrophoresis from the anode the to cathode.
2. ACE (100%) > DnBP (91%) > DEHP (55%) > DiNP (46%)
3. The practice of electrode polarity reversal would maintain neutral pH for sediment after remediation.
Yang et al., 2016
Phthalate esters and acetaminophen
Initial concentration:(1) DEHP, 0.5-23.9 mg/kg;(2) DBP:0.3-30.3 mg/kg;(3)diethyl phthalate (DEP): 0.1-1.1 mg/kg; DPP, DPhP, BBP, DHP, and DCP were below detection limits.
Electrolyte: Houjing River water & daily injection of 3.14g Na2S2O8 plus 0.63g nano-Fe3O4
Potential gradient: 2 V/cm Reaction time: 14 days
1. Daily injection of S2O82− and nano-Fe3O4 slurry into the anode reservoir is appropriate.
2. 93.87% removal of DnBP and 53.87% removal of DEHP were octylphenol and triclosan.
Electrode: platinized titanium bars Electrolyte: NaNO3
Current : 20 mA Reaction time: 28 days.
1. EE2/E2/BPA/NP/O: Between 52% ~ 66% of removal efficiency.
2. The highest quantities of contaminants moved towards the catholyte, particularly when the EOF was kept constant.
3. The extent of mobilization towards the cathode end was mainly dependent on compounds solubility and octanol-water partition coefficient.
Guedes et al.,2014
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表 2.10 電動力技術對於有機污染土壤處理彙整-模場尺度
Contaminants Experiment parameter Summary results Literature
Cl-,NO3-,SO4
2-Electrode: graphite electrodes (7 cm in diameter × 25 cm in length)
Potential gradient:1 V/cm Reaction time: 10 days
EK cell size: 100 cm×100 cm×25 cm Electrode configuration :hexagonal
1. The chloride-removal efficiency was −62.3% in the top layer, −32.0%
in the middle layer, and 31.3% in the bottom layer.
2. The nitrate-removal efficiency was 21.5% in the top layer, 35.6% in the middle layer, and 44.7% in the bottom layer.
3. The average removal efficiency of sulfate was 25.4% in the top layer, 17.1% in the middle layer, and 24.4% in the bottom layer.
Kim et al .;2012
Atrazine and oxyfluorfen
Electrode: Graphite (100.0 cm2) Electrolyte: 1000 mg/dm3 SDS Potential gradient: 1 V/cm Reaction time: 15 days
EK cell size: 20 cm*10 cm*10 cm(methacrylate) Electrode configuration :linear
1. Reversible changes in the polarity control avoid extreme pH values.
2. The evaporation loses in reversible electrokinetic adsorption barriers (45–50%) were lower than those obtained in Electrokinetic soil flushing compared to (60–65%).
3. The adsorption of pesticide onto activated carbon prevents evaporation.
Vieira dos Santos et al.,
2016
oxyfluorfen
Electrode: Graphite(1 cm × 1 cm× 10 cm3) .
Electrolyte: with calcium dodecylbenzenesulfonate as the surfactant, ie, cleansing agent
Potential gradient: 1 V/cm Reaction time: 34 day
EK cell size: 70 cm× 50 cm× 50 cm
1. Initial concentration of oxyfluorfen is 20 mg/kg.
2. After only a 34 day treatment, the concentration decreased from 20.0 to 7.4 mg/kg
3. Without any treatment ,only 5.5 % of oxyfluorfen was removed, whereas when electrokinetic fence is applied, the removal efficiency is approximately 63% (60.7% of improvement vs. natural volatilization).
Risco et al.,2016
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表 2.8 電動力技術對於有機污染土壤處理彙整-模場尺度(續)
Contaminants Experiment parameter Summary results Literature
2,4-dichlorophen oxyacetic acid
Electrode: Graphite (10.0 cm × 10.0 cm × 1.0 cm) Electrolyte: tap water
Potential gradient: 1 V/cm Reaction time: 15 days
EK cell size: 10 cm×10 cm×20 cm
1. It was possible to remove 90.2% and 73.6% of 2,4-D in the electro-remediation powered with DC power supply and PV solar panels, respectively.
2. The average daily charge supplied during electrokinetic soil flushing powered with solar panel is 6.2 Ah /d.
Souza et al .,2016
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測到，如表2.11所示，許多文獻使用化學氧化方式處理三氯沙。
Ren et al. (2014) 研究了三氯沙在高頻超音波（850 kHz）和各種 電極的水溶液中的聲電化學降解。金剛石鍍鈮(niobium)電極具有最佳 降解效果，並比較不同參數對降解程度的影響，發現在pH值2.5，三 氯沙初始濃度為1 mg/L之液相環境下，經過15 分鐘、10 V電壓之超音 波電化學處理後，可以達到92 %的降解效果。
Munoz et al. (2012)於初始濃度為10 mg / L之三氯沙水溶液中，利 用類芬頓(Fenton-like)反應進行降解實驗，在鐵和過氧化氫濃度分別 為1 mg/L、5 mg/L，溫度為25 ℃下，在小於1 小時幾乎使三氯沙完全 降解，顯示類芬頓法對於三氯沙處理之可行性。
Song et al. (2012)改良類芬頓(Fenton-like)反應利用BiFeO3磁性奈 米顆粒作為過氧化氫之催化材料進行三氯沙降解，研究結果發現初始 TCS濃度34.5 μmol/L，單獨使用過氧化清不添加催化劑之情況下反應 180分鐘後，僅有些微降解，但當加入0.5 g/L的BiFeO 3奈米顆粒後，
三氯沙的去除率提高到82.7 %，研究結果表明異質系統對於催化H2O2， 具有一定之潛力。
Nfodzo et al. (2011)研究以硫酸根高級氧化技術降解三氯沙，並評 估由Fe2+，Co2+，Cu2+和Ag+金屬作為催化劑，催化單氧過硫酸鹽(PMS) 和過硫酸鹽(SPS)的效果，結果發現對於兩種過硫酸鹽而言，不同金 屬有不同的催化效果，對於PMS而言，Co2+具有較佳的催化效果，相 對於Co2+而言，鐵對於其催化效果有限，雖然同樣可以使TCS的處理 效果達到接近100 %，然而以催化劑的劑量相比，Fe2+催化PMS之比
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例為40:1，相較於Co2+的3:1而言，使用的劑量較大，顯示Co2+對於PMS 之催化能力。
Gao et al. (2016)研究中，在水相環境下研究TCS的降解，其中考 慮了代表性陰離子Cl-和HCO3，溶液pH，天然有機物如黃腐酸的影響， -結果表明，TCS的降解受到溫度和pH依賴性，雖然酸性條件更有利於 降解，但TCS亦可以在中性pH值下有效去除，這使得過硫酸鹽氧化成 為地下水中較難降解有機物氧化的優先選擇。
Chen et al. (2016)研究結果表明過錳酸鉀對於液相環境下處理三 氯沙具一定之效果，在最佳反應條件之pH=8，[TCS]0=20 mg/L，
[KMnO4]=0.31 mM處理下，經過120秒處理後可以達到99%之處理效 果，然於pH=4時觀察到最低之TCS降解效果，經過5分鐘降解後僅有 78%之降解效果，顯示其對於pH值具有較高依賴性。
相比下Fenton試劑(H2O2/Fe2+)、臭氧(O3)及過錳酸鉀(KMnO4)較常 和過硫酸鹽進行比較，然而上述氧化劑於實際應用中有幾個較為重要 之缺點，如: H2O2於Fe2+存在之狀況下會快速耗盡，且由於催化劑之 特性影響，Fenton反應較適合於低pH值之情況發生，而O3微溶於水 (~40 mg/L)和在水中之低傳送率限制其應用，KMnO4對污染物具有選 擇性，因此，過硫酸鹽（S2O8
2-）(SPS)系統於近年來受到重視，而在 三氯沙之處理中，過硫酸鹽之應用目前還尚未普遍，僅有初步研究，
故其於電動力技術之發展潛能相對於羥基氧化技術較高且較穩定，此 點也已受到許多研究之重視。
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表 2.11 三氯沙液相處理技術彙整
Methods Experimental parameters Reaction time Removal efficiency Literature
Sonoelectrochemical [TCS0]=1 mg/ L, pH=2.5 15 min 92% Ren et al., 2014
Fenton-like oxidation Fe3+: 1 mg/L, H2O2: 25 mg/L, [TCS0]=10 mg /L 60 min 95% Munoz et al., 2012
Enhanced Fenton-like process
[TCS0]=34.5 μmol/ L ,H2O2 (10.0 mmol/L), pH 6.0 at room temperature,
BiFeO3 MNSPS (0.5 g/L); 180 min 82.7% Song et al., 2012
Sulfate radical AOP [TCS0]= 9 mg/L ,Initial pH=7, oxidant and metal concentrations:
0.093 mM
30 min >95% Nfodzo et al., 2011
Thermally activated persulfate system
[TCS0]= 0.031 mM,[K2S2O8]0= 0.155 mM, Temperature =80℃ 100 min ≒99% Gao et al., 2016
AOP with potassium permanganate
[TCS0]=20 mg/L, [KMnO4]=0.31 mM, Temperature =25℃ 120 sec ≒99% Chen et al., 2016
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