The reuse of laundry machine wastewater

Transcription

1 The reuse of laundry machine wastewater Michela Saracino CNR - ISOF Coffee Talk, 22 January 2013, Bologna

2 Education January 2013: PhD student in Chemistry, University di Bologna, Department of Industrial Chemistry October 2009: Degree in Pharmaceutical Chemistry and Technology, University of Bologna Work experience Nov 2010 on going: research grant Project of Industrial Innovation Efficienza Energetica Industria 2015, Energy & Appliances 2015

3 PROJECT Energy & Appliances Water quality control 2 1 3

4 SURFACTANTS NON IONICS ANIONICS CATIONICS AMPHOTERICS Sodium Dodecylbenzenesulfonate Triton X-100 Hexadecyltrimethylammonium bromide

5 ADVANCED OXIDATION PROCESSES (AOPs) UV / H2O2 pollutant Photocatalysis (UV/TiO2) HO non thermal plasma UV / O3 Ultrasounds e-beam, γ rays

6 Degradation of surfactant solutions Experimental set-up Photochemical reactor: Rayonet RPR UVC lamps (Sylvania, 8W, 254nm) Photochemical reactor Quartz glass tube: 250 ml of solution (20 mg/l) AOP treatment: UV+TiO2 TiO2:VP AEROPERL P25/20 Evonik(0,01% p/v) Pure air Cooling system Treatment time: 30, 60, 90, 120, 240 minutes UVC lamps Analysis Total Organic Carbon,TOC (LCK 385, Hach Lange kit) HPLC (Agilent 1260)

7 TOC (mg C/L) Anionic surfactant + UV + TiO2 HPLC trace with fluorescence detection Sodium Dodecylbenzenesulfonate (SDBS) time 0 TOC trend mg/l -11.4% -48.8% after 30 min. SDBS <10% % <3 mg/l <3 mg/l Time (min.)

8 TOC (mg C/L) Non ionic surfactant + UV + TiO2 Triton X-100 HPLC trace with fluorescence detection time 0 TOC trend mg/l -27.5% -51.5% after 30 min. Triton <10% < 3 mg/l < 3 mg/l Time (min.)

9 TOC (mg C/L) Cationic surfactant + UV + TiO2 Hexadecyltrimethylammonium bromide (HTAB) HPLC trace with Corona detector time 0 TOC trend mg/l -7.5% after 30 min. HTAB <10% % -33.8% -47.7% -70.7% Time (min.)

10 Technological transfer: advanced oxidation processes on laundry machine wasterwater Advanced oxidation treatment Washing cycle: - washing phase ~ 15 L st - 1 rinse ~ 20 L nd - 2 rinse ~ 20 L

11 Laundry machine tests - treatment prototype 2 serial tubes (ø = 8cm, l = 70cm), including 2 UVC lamps (Hg low pressure, 254nm, 39 W)

12 Degradation of laundry machine wasterwater Experimental set-up Laundry machine test legislation cotton strips including standard dirt AOP treatment (UV + H2O2 10 mm) Photophysical treatment (UV) 10 L of laundry machine wastewater Treatment time: 1, 2, 4 hours Analysis Surfactant concentrations (LCK 332, LCK 333 Hach Lange kits) TOC (LCK 385 Hach Lange kit)

13 TOC (mg C/L) Anionics (mg/l) Non Ionics (mg/l) 2 rinse water treatments: UV vs UV + H2O rinse water + UV 0 2 rinse water + UV 2 rinse water + UV +H 2 O rinse water + UV +H 2 O Time (min.) Time (min.) rinse water + UV 2 rinse water + UV +H 2 O Time (min.)

14 Washing cycles with treated water Treatment of 2 nd rinse water (20L) using UV + H2O2 (3 hours) Reuse of treated water for a new washing cycle Washing water Dirt Effectiveness of the new washing cycle: refletance values of the cotton strips supply net water (reference data) 2 nd rinse water treated by UV+H 2 O 2 2 nd rinse water treated by UV+H 2 O 2 drop-wise white 80.5 ± ± ± 0.9 sebum 60.8 ± ± ± 1.0 coal & oil 35.7 ± ± ± 1.3 blood 37.3 ± ± ± 1.2 milk & chocolate 41.6 ± ± ± 1.0 red wine 50.4 ± ± ± 2.4 Total ± 1.7 A ± 2.9 B ± 3.3 C Delta A-B = 11.5 Delta A-C = 5

15 Conclusions Advanced Oxidation Processes proved to be effective in degradation of surfactants and in TOC reduction Laundry machine wastewater tests Effective degradation of surfactants and TOC reduction using UV + H2O2 but H2O2 costs The photocatalytic process (where TiO2 remains stable during the reaction) would be the ideal solution to be included in the new laundry. Perspectives Development of a photocatalyst supported on solid material To scale the best solution inside the new-eco compatible laundry

16 Acknowledgments ISOF-CNR Alberto Zanelli Salvatore Silvano Emmi Luca Pretali Biagio Esposito Maria Luisa Navacchia Massimo Capobianco UNIVERSITY OF BOLOGNA, DEPARTMENT OF INDUSTRIAL CHEMISTRY Fabrizio Passarini INDESIT COMPANY Annalisa Ciarletta Alessandra Papetti Nicola Colucci Mauro Mancini Cinzia Felice Marco Peduto

17 THANK YOU!