APPLICATION OF FENTON REAGENT IN THE TEXTILE WASTEWATER TREATMENT UNDER INDUSTRIAL CONDITIONS

Transcription

1 APPLICATION OF FENTON REAGENT IN THE TEXTILE WASTEWATER TREATMENT UNDER INDUSTRIAL CONDITIONS Stanisław Ledakowicz 1 & Lucyna Bilińska 2 1 Department of Bioprocess Engineering, Technical University of Lodz, Lodz, Wolczanska 213, Poland, stanleda@p.lodz.pl 2 Factory of Color Biliński Co., Konstantynów Łódzki, Mickiewicza 29

2 Outline of the presentation Introduction Textile wastewater Overview of Fenton reaction Experimental Results and Discussion Conclusions

3 Textile wastewater generated in Bilinski Co.Factory l x 7 10 baths x 40 dying machines Bleaching Rinsing Acidifing Deying Acidifing Washing I Washing II Washing III Rinsing Softening * Fir reactive dying m 3 /d Textile waste water effluent consists of mainly three components: (1) effluent from preparation process, (2) effluent from dyeing and (3) from finishing processes. Effluents released from dying process, consists of dyes, salts and surfactants. The dyes used in textile industry are varieties of synthetic organic compounds, forms the major constituent of the textile waste water and thus are also major pollutant.

4 Cotton finishing process Bleaching of cotton fabric is generally processed at C for 1 h, reactive dyeing can be carried out at 60 C or C depending on the dyestuff properties.

5 Textile Factory Biliński Co. in Konstantynów Łódzki

6 Characteristics of textile wastewater Parameter, unit COD, mg/l BOD 5, mg/l N total, mg/l 5 70 P total, mg/l 1 6 Conductivity ms/cm Chlorides, mg/l Sulfates, mg/l Color, Pt-Co ph Baban et al. (2003), Ciardelli et al. (2001), Eremektar (2007), Mihułka et al. (2003), Villegas-Navarro et al. (2001) Wastewater from dyehouse Biliński Co. Parameter/Process Bleaching Rinsing Acidifying Dyeing Acidifying Washing Rinsing Final effluent COD mg O 2 /l ph Chlorides mg/l Out of range Nitrates mg/l , Nitrites mg/l Phophates mg/l Sulfates mg/l

7 Mechanism of Fenton reaction H 2O2 Fe H Fe H 2O HO HO Fe k Fe HO R H k i H 2O R HO R H k j H 2O R HO HO R H k k H 2O R Fe 2R j k i 3 j 3k R k i Fe k 5 product(dim er) R Fe H k k Fe i j k product RkH k 1-76 M -1 s -1 ; k(h 2 O 2 +OH ) = 2.2 x 10 7 M -1 s -1 k 2-3 x 10 8 M -1 s -1 ; k M -1 s -1 ;

8 Experimental with Fenton reagent Materials C.I. Reactive Black Trade name Setazol DPT M= Max. absorbance at λ=596 nm FeSO 4 7H 2 O Perhydrol H 2 O 2 conc. 30% LDR liquid dispersing and sequestering agent based on naphthalene sulphonic acid condensate and carboxylates H 2 SO 4 conc.94% aqueous solution1:10 NaCl up to 100g/l

9 Effect of ph on Fenton discoloration 1,0 YKHL, ph=3 YKHL, ph=2 YHB, ph=3 YHB, ph=2 BDPT, ph=3 BDPT, ph=2 0,8 0,6 A/A 0 0,4 0,2 0, time in sec. The fastest discoloration proceeded with ph value equal to 3

10 Influence of the initial concentration of H 2 O 2 and Fe(II) on k d for Fenton reaction Optimum: FeSO 4 :H 2 O 2 =1:10

11 Ratio FeSO4: H =1:10 has been chosen for the further decoloration tests Technical University of Lodz Influence of the initial H 2 O 2 and Fe(II) concentrations on Fenton discoloration A/A 0 1,0 0,9 0,8 0,7 0,6 0,5 0,4 25mgFeSO 4 :125mgH 2 O 2 25mgFeSO 4 :250mgH 2 O 2 75mgFeSO 4 :375mgH 2 O 2 75mgFeSO 4 :750mgH 2 O 2 100mgFeSO 4 :500mgH 2 O 2 100mgFeSO 4 :1000mgH 2 O 2 FeSO 4 : H =1:5 and 1:10 0,3 0,2 0,1 0, time in sec.

12 Influence of the initial H 2 O 2 and Fe(II) concentrations on Fenton discoloration stężenie barwnika [mg/dm 3 ] stężenie soli żelaza [mol/l] stężenie H 2 O 2 [mol/dm 3 ] 10-3

13 Influence of NaCl concentration on Fenton discoloration 1,0 0,8 0,6 C.I. Reactive Black 5 1g/l NaCl 5g/l NaCl 10g/l NaCl 20g/l NaCl 40g/l NaCl 80g/l NaCl C/C 0 0,4 0,2 0, time in min.

14 Influence of NaCl concentration on Fenton discoloration rate 1,2x10-3 1,0x10-3 C.I. Reactive Black 5 (1-C/C 0 )/t, 1/s 8,0x10-4 6,0x10-4 4,0x NaCl concentration, g/l

15 Influence of surfactant addition on Fenton discoloration Perigen LDR - liquid dispersing and sequestering agent based on naphthalene sulphonic acid condensate and carboxylates 1,0 0.5g/l LDR 1.0g/l LDR 2.0g/l LDR C.I. Reactive Black 5 0,8 0,6 C/C 0 0,4 0,2 0, time in min.

16 Fenton discoloration of simulated and real industrial wastewater 1,0 0,8 simulated BDPT, 250mg/lFeSO 4 simulated BDPT, 350mg/lFeSO 4 simulated BDPT, 500mg/lFeSO 4 real BDPT, 350mg/lFeSO 4 0,6 real BDPT, 500mg/lFeSO 4 C/C 0 0,4 0,2 0, time in sec.

17 After two solutions containing the reagents are mixed, they are studied by spectroscopy methods. The dead time 1-2 ms is time between the end of mixing the two solutions and the beginning of observation of the kinetics. Stopped -flow spectrophotometer DX-17 MV (Applied Photophysics) (millisec) and Hewlett-Packard 8452A diode-array spectrophotometer ph = 2; V = 150 l; H 2 O 2 conc. = 0.5 x 10-4 mol/dm 3 ; Dye conc. = 25 mg/dm 3 FeCl 2 4H 2 O or FeSO 4 7H 2 O conc. = (0.5-5) x 10-3 mol/dm 3 ;

18 UV Absorbance changes of Acid Blue 62 during treatment with FeCl 2 4H 2 O/H 2 O 2 1,0 FeCl 2. 4H 2 O x 10-3 M; Absorbance 0,8 0,6 0,4 0,2 direction of spectrum changes isosbestic point H 2 O x 10-4 M; Acid Blue mg/dm 3 time: 200 sec direction of spectrum changes isosbestic point 0, wavelength [nm]

19 Pseudo-first order rate constant of decoloriation by Fenton's reagent versus Fe 2+ concentration O NH2 SO3Na 0,6 FeCl 2. 4H 2 O O O NH NH C CH3 0,5 0,4 Acid Blue 62 Acid Red 27 Reactive Blue 81 FeSO 4. 7H 2 O NaO3S N=N OH SO3Na k [ s -1 ] 0,3 Acid Blue 62 Acid Red 27 Reactive Blue 81 0,2 SO3Na Cl 0,1 N N NH SO 3 Na N=N NaO 3 S OH NH N SO 3 Na Cl 0,0 0,0 0,1 0,2 0,3 0,4 0,5 Fe 2+ concentration [mol/dm 3 ] x 10 2

20 Pulse Radiolysis A method of studying fast chemical reactions in which a sample is subjected to a pulse of ionizing radiation, products formed by the resulting reactions are studied spectroscopically. Accelerator ELU-6E Pulse 17 ns energy 6 MeV current of pulse 10 A time of reaction 200 ns - 10 s 1 - UV & VIS lamp; 2 - cuvette (1 cm 2 ); 3 - electron flux; 4 - accelerator; 5 - computer; 6 - monochromator; 7 - system of mirrors

21 Water radiolysis H O e 2 H 2O e e H O e 2 aq H 2O eaq H 2O * H 2O * H HO nbond. Aqueous electron an electron released during ionization of a water molecule, surrounded by water molecules so that the electron cannot escape. Selection of *OH radicals by saturation with N 2 O eaq N O H HO N 2 2 N 2O H N 2 HO Selection of Cl - 2 ion-radicals with N 2 O saturation, acidified with HCl (ph=1) HO Cl HOCl HOCl H H 2O Cl Cl Cl Cl 2

22 Pulse Radiolysis Acid Red 27 Radioliza impulsowa A 0,00-0,05-0,10 Cl 2 *- stężenie barwnika: 25 mg/dm 3 długość fali: 520 [nm] Opis kinetyczny OH * kinetyka pseudo-pierwszorzędowa k = 0.62 x 10 6 [s -1 ] Cl 2 *- model dwóch reakcji równoległych I-rzędowych k 1 = 0.62 x 10 6 [s -1 ] k 2 = 1.43 x 10 3 [s -1 ] HO HOCl Cl Cl Cl H Cl HOCl 2 H 2 OH * -0,15 0,0 5,0x10-6 1,0x10-5 1,5x10-5 2,0x10-5 2,5x10-5 3,0x10-5 3,5x10-5 O Cl czas [sec]

23 HPLC of Triton X-100 aqueous solution treated with *OH CH 3 CH 3 H 3 C - C - CH 2 - C - - O - ( CH 2 - CH 2 O ) n - H CH 3 CH3 0 min 5 min 15 min wielkość piku czas retencji

24 Chromatograms of Triton X-100 aq. solution treated with *OH radicals a) 0 min., b) 10 min., c) 20 min., d) 40 min

25 NMR 1 H data of Triton X-100 aqueous solutions non-treated after oxidation

26 Oxidation vs. flocculation Percentage of initial values of COD [%] percentage of COD reduction after oxidation percentage of COD reduction after oxidoflocculation H 2 O 2 conc.: 0.13 mol/dm 3 0 0,0 2,0x10-3 4,0x10-3 6,0x10-3 8,0x10-3 1,0x10-2 FeSO 4. 7H 2 O [mol/dm 3 ] With Fenton s reagent 88% of COD was destroyed, however, 60% of COD was found in the sediment. The average of COD reduction for all experiments was 2530% after oxidation and 90% after flocculation.

27 Oxidation vs. flocculation Synthetic wastewater simulating the real textile wastewater from knitting companies Alizarine blue (C. I ) Tetrapol CLB (sodium alkilonaphthaleno-sulfonate & sodium salt of sulfated fatty acid) Avivage KG (anionoactive sulfoesters of higher fatty alcohols & and minerals) 3 9% 1 31% 2 60% 1 - percentage of COD removal by oxidation, 2 - percentage of COD in the sediment, 3 - percentage of COD in the solution after oxidoflocculation.

28 Conclusions Fenton reagent appeared to be very effective in degradation of aqueous solution of many dyestuffs and surfactants. Inhibition effect of NaCl presence in textile wastewater on discoloration has been found: the higher content of NaCl the poorer discoloration degree. The emulsification effect of surfactants present in textile wastewater in the concentration above CMC causes a decrease of discoloration rate. Simulated textile wastewater are not the same with respect to discoloration by Fenton reagent as real wastewater generated during reactive dying in industrial scale.

29 Perspectives Experimental set-up: compound parabolic collector (CPC) for degradation of Reactive Blue 4 solar reactor (50 L - CSTR, centrifugal recirculation pump & solar collector unit with area of 2m 2 ) Applied Catalysis B: Environmental 80, (1-2),, 42-50, 2008

30 Acknowledgement The great contribution of my previous PhD students has been acknowledged, in particular : Dr. Eng. Renata Maciejewska- Żyłła, from Textile Research Institute in Lodz, Dr. Eng. Kinga Skalska, Department of Environmental Engineering Systems of TU Lodz, and also Dr. Eng. Jan Perkowski from Institute of Applied Radiation Chemistry of TU Lodz, as well as financial support of Polish Ministry of Higher Education and Science in the form of many grants.

31 Thank you very much for your kind attention