Performance of the deep bed filter at its

Performance of the deep bed filter at its loading with particles and microorganisms Leon Gradon and Ewa Sztuk e-mail: L. [email protected] pw. edu. pl phone: +48 22 234 91 80 address: Warynskiego 1, 00 -645 Warsaw, PL Separation Techniques, 26 -28 September 2016, Valencia

Contents § Introduction § Principles of deep-bed filtration § Mechanisms of particle and bacteria deposition § Filter loading and biofouling § Formation of fibrous filters with the melt-blown technique § Testing of filters § Conclusions Separation Techniques, 26 -28 September 2016, Valencia

Introduction – World Trends world population growth growing demand for water climate changes water reclamation and reuse * www. unwater. org Separation Techniques, 26 -28 September 2016, Valencia

Introduction – World Trends * www. ces. uoguelph. ca Separation Techniques, 26 -28 September 2016, Valencia

Introduction – depth filtration untreated water AIM CHALLENGES maximalize the time of filtration with high filtration efficiency and low pressure drop 1. Resuspension of deposit filtration efficiency agglomerate break relocation pressure drop 2. Removal of nanoobjects time 3. Biofouling filtered water Separation Techniques, 26 -28 September 2016, Valencia

Principle of deep-bed filtration α(z), df(z) c 0 ck z Separation Techniques, 26 -28 September 2016, Valencia

Mechanisms of particle deposition Separation Techniques, 26 -28 September 2016, Valencia

Composite filters: testing Henry C. et al. (2013) Langmuir, 29 (45), 13694 -13707 Polypropylene Zinc oxide Silver Halloysite Hematite Arizona Test Dust ζ [m. V] -40 -6 -33 -30 -20 -30 Separation Techniques, 26 -28 September 2016, Valencia

Performance of filter during loading A B SEM images of a fibrous filter tested on solid particles. CLSM images of a fibrous filter tested on natural river water. A – outer layer, B – 1 mm deep, C – 5 mm deep. Separation Techniques, 26 -28 September 2016, Valencia

Formation of fibrous deep-bed filter 1 – polymer container 2 – extrusion screw 3 – electric heater 4 – die 5 – compressor and air heater 6 – fiber collector Separation Techniques, 26 -28 September 2016, Valencia

Single fiber formation Separation Techniques, 26 -28 September 2016, Valencia

continuity equation: equation of motion: Newton’s constitutive equation: energy balance equation: Separation Techniques, 26 -28 September 2016, Valencia

Fiber axial stretching force Separation Techniques, 26 -28 September 2016, Valencia

Distribution of process parameters inside the fiber Separation Techniques, 26 -28 September 2016, Valencia

Polymer molecules orientation Separation Techniques, 26 -28 September 2016, Valencia

Formation of fibrous deep-bed filter Separation Techniques, 26 -28 September 2016, Valencia

Theory Mixed – fiber filters: testing nanofiber microfiber Przekop R. , Gradon L. (2008) Aerosol Science and Technology, 42, 483 -493. microfiber nanofibers filtration efficiency [%] Experiment 100 80 60 40 20 0 0. 5 1. 0 particle size [μm] standard 1. 5 2. 0 mixed-fiber Separation Techniques, 26 -28 September 2016, Valencia

Performance of filter during loading Separation Techniques, 26 -28 September 2016, Valencia

100 2. 5 80 2. 0 pressure drop [bar] filtration efficiency [%] Performance of filter during loading 60 40 1. 5 1. 0 0. 5 20 0. 2 0. 4 0. 6 time [-] 0. 8 1 0 0. 2 0. 4 0. 6 0. 8 1 time [-] Separation Techniques, 26 -28 September 2016, Valencia

Formation of fibrous deep-bed filter 1 – polymer container 2 – nanoparticles container 3 – twin-screw extrusion cylinder 4 – die 5 – composite monofilament 6 – water bath 7 – knife system 8 – composite granulate Separation Techniques, 26 -28 September 2016, Valencia

Filter modifications with nanoparticles Separation Techniques, 26 -28 September 2016, Valencia

Filter modifications with nanorods 1) 2) Separation Techniques, 26 -28 September 2016, Valencia

Filter modifications with nanoparticles Antibacterial and bacteriostatic plate test: A - on E. coli on differentiating medium incubated for 24 h at 37°C, B – on B. subtilis on LB medium incubated for 24 h at 37°C. PP – pure polypropylene. 1, 2, 3, 4 – layers of modified fabric starting from the filter’s inlet. Separation Techniques, 26 -28 September 2016, Valencia

Composite filters: testing Changes of optical density of test cultures induced by the presence of particular filters Separation Techniques, 26 -28 September 2016, Valencia

Performance of filter during loading Separation Techniques, 26 -28 September 2016, Valencia

Biofouling dead / live bacteria number [-] 1. 4 1. 2 1 0. 8 0. 6 0. 4 0. 2 0 0 20 40 60 80 100 t standard composite with 1% Zn. O, 0. 1% Ag Separation Techniques, 26 -28 September 2016, Valencia

Biofouling 2. 5 pressure drop [bar] 2. 0 1. 5 1. 0 0. 5 0. 0 0 20 standard 40 60 time [min] 80 100 composite with 1% Zn. O, 0. 1% Ag Separation Techniques, 26 -28 September 2016, Valencia

Conclusions § Deep-bed filters are efficient tools for removal of submicron particles and microorganisms form water. § Filter loading with abiotic particles and colonization of microorganisms within the filter significantly reduce the filter life-time. § Melt-blown is a useful technique for designing of deep-bed structures for uniform distribution of deposits in the filter volume. § Composite fibers consisting Ag/Zn. O nanoparticles on the surface significantly reduce biofouling effect during collection of microorganisms in filter. Separation Techniques, 26 -28 September 2016, Valencia

Thank you for your attention Separation Techniques, 26 -28 September 2016, Valencia