Advanced oxidation for aromatic amine mineralization after aerobic granular sludge treatment of an azo dye containing wastewater

Transcription

1 Advanced oxidation for aromatic amine mineralization after aerobic granular sludge treatment of an azo dye containing wastewater Ana M. T. Mata (1,2), Nídia D. Lourenço (1), Helena M. Pinheiro (1) (1) Instituto Politécnico de Setúbal, Rua Vale de Chaves, Campus do IPS, Estefanilha, Setúbal, Portugal (2) ibb, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal

2 Introduction Textile wastewater - negative environmental impact - heavily loaded regarding organic carbon and color (70% from azo dyes) 2 phase biological treatment anaerobic dye reduction (color removal) aerobic further oxidation (COD removal) Aerobic Granular Sludge Sequencial Batch Reactor (AGS-SBR) Colorless dye persisten metabolites Intense color e - colorless colorless Acid Red 14: p-4a1ns (stable amine) o-amine (unstable) 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

3 Aim The aim of this work was: - Apply advanced oxidation processes (AOP) in simple configuration, as a post-treatment of an AGS-bioreactor to promote the mineralization of the azo dye metabolites Ozonation UV irradiation - The recirculation of the AOP treated effluent back to the AGS-bioreactor was also tested to evaluate the improvement of the overall removal of organic load (COD) 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

4 Experimental System 40 mg/l Dye (AR14) 1000 mg/l COD Emsize1 Textile Wastewater AGS-SBR 6h cycle 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

5 Experimental System 40 mg/l Dye (AR14) 1000 mg/l COD Emsize1 Textile Wastewater Fill 2h AGS-SBR effluent Iddle AGS-SBR 6h cycle Anaerobic 3h Discharge Aeration Settling 3 to 5 min 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

6 Experimental System 40 mg/l Dye (AR14) 1000 mg/l COD Emsize1 Textile Wastewater Fill 2h AGS-SBR effluent Iddle AGS-SBR 6h cycle Anaerobic Color and COD removal > 80% but Recalcitrant aromatic amine (41ANS) Discharge Aeration 3h Settling 3 to 5 min AGS-SBR effluent collected along a period of 2 days for following experiments 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

7 Experimental System AGS-SBR effluent Ozonation post-treatment 60-watt Electronic Ozonizer 5 L/min Sample: 800 ml in an 1L cylinder Ozone fed for 60 minutes samples collected at 0, 5, 10, 20, 30, 45 and 60 min Followed by HPLC UV-vis COD Color and COD removal > 80% but Recalcitrant aromatic amine (41ANS) 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

8 Experimental System AGS-SBR effluent Color and COD removal > 80% but Recalcitrant aromatic amine (41ANS) Ozonation post-treatment UV irradiation post-treatment 60-watt Electronic Ozonizer 5 L/min Sample: 800 ml in an 1L cylinder 150-watt, medium pressure mercury lamp ( nm) Sample: 600 ml in a 850-mL photoreactor Ozone fed for 60 minutes samples collected at 0, 5, 10, 20, 30, 45 and 60 min 30 min irradiation samples collected at 0, 5, 10, 20 and 30 min Followed by HPLC UV-vis COD Followed by HPLC UV-vis COD 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

9 Experimental System Recirculation of the AOP treated effluent back to the AGS-bioreactor was also studied Followed by HPLC UV-vis COD TSS 13 th IWA SWWS and 5 th ROS, Athens SET. 2016

10 Results Ozonation post-treatment 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

11 Results Ozonation post-treatment 4A1NS concentracion by HPLC 3, B UV-vis spectra 2,5 Absorbance 2 1,5 1 0 min (SBR effluent) 10 min Ozonation 60 min Ozonation 0, Wavelength (nm) HPLC chromatogram 5 min O 3 -> 85% conversion of 4A1NS disappearance amine peak at 320 nm General disappearance of residual peaks or retention time reduction COD value was unchanged (no mineralization) 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

12 Results UV irradiation post treatment

13 Results UV irradiation post treatment 4A1NS concentracion by HPLC 3, B UV-vis spectra 2,5 Absorbance 2 1,5 1 SBR effluent (0 min) 10 min UV irradiation 30 min UV irradiation 0, Wavelength (ƞm) HPLC chromatogram need 20min UV -> 85% conversion of 4A1NS at 10min amine peak at 320 nm still remains disappearance of all residual metabolites COD value almost unchanged (no mineralization) 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

14 Results Recirculation to bioreactor after AOP 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

15 Absorbance Results Recirculation to bioreactor after AOP 3,5 3 2,5 2 1,5 1 UV-vis spectra beginning of biological cycle (O3) end of biological cycle (O3) beginning of biological cycle (UV) end of biological cycle (UV) 0, λ (nm) no change of the ozonised effluent a slight absorbance decrease of UV-irradiated effluent HPLC essentially unchanged both for Ozone an UV-irradiated effluent recirculation to bioreactor increments COD removal by 20% - ozonised effluent 15% - UV-irradiated effluent 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

16 Conclusions 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

17 Conclusions - The conversion of the recalcitrant 4A1NS amine was successfully achieved using the two AOP tested as post-treatments - A removal efficiency of 85% for the recalcitrant amine could be obtained with either 5 min of ozonation or 20 min of UV irradiation. - COD removal in both AOP treatments was insignificant, but a simulated recirculation of these effluents back to the biological treatment achieved removal yields of 15 to 20%. - It can be concluded that ozonation and UV irradiation are promising options as polishing treatments for the effluents coming from AGS-SBR treatment of textile wastewaters, aiming to eliminate recalcitrant aromatic amines resulting from azo dye bioreduction. 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016

18 Acknowledgements - This work was financed by Fundação para a Ciência e a Tecnologia (FCT, Portugal) through the BIOTEXTILE project (PTDC/EBB-EBI/120624/2010) and the funding received by ibb - Institute for Bioengineering and Biosciences (UID/BIO/04565/2013). - A.M.T. Mata and N.D. Lourenço acknowledge the financial support of FCT through doctoral (SFRH/BD/49432/2009) and post-doctoral (SFRH/BPD/88095/2012) research grants, respectively. - Instituto Politécnico de Setúbal is also acknowledged for financial support granted to A.M.T. Mata. - Funding received by ibb from Programa Operacional Regional de Lisboa 2020 (Project N ) is also acknowledged. Thank you for your attention! anatavaresmata@gmail.com 13 th IWA SCWWS and 5 th SCROS, Athens SET. 2016