using the Ultra Low Pressure Ultra Filtration (ULPUF) process Univ. Prof. Dr. Ing. Franz Bernd Frechen Universität Kassel

Transcription

1 Simple Decentralised DrinkingWater Treatment: using the Ultra Low Pressure Ultra Filtration (ULPUF) process Univ. Prof. Dr. Ing. Franz Bernd Frechen Universität Kassel Chair, IWA Specialist Group Membrane Technology Winner 2011 in the category society Slide 1

2 WASH water, sanitation & hygiene Without t safe water, hygiene is problematic Sanitation only does not avoid diseases Optimal results are achieved if all three issues are addressed Safe water is a core target Transportation of safe water in rural areas is not safe and much too expensive Decentralized water treatment is the key concern and membrane technology is the key technology Slide 2

3 The MDG concerning drinking water Rd Reduce by hlfth half the proportion of people without sustainable access to safe drinking water until the year 2015 (based on situation in 1990) Done: from 24% down to 9% Not done concerning numbers: from 1270 million down to 663 million Slide 3

4 Actual situation World rural population: unimproved water source 1,000, , cap pita 600, , , Source: WHO/UNICEF Joint Monitoring Programme (JMP) for Water Supply and Sanitationhttp estimates/tables/ wssinfo org/data Slide 4

5 Actual situation China rural population: unimproved water source 250, , cap pita 150, ,000 50, Source: WHO/UNICEF Joint Monitoring Programme (JMP) for Water Supply and Sanitationhttp estimates/tables/ wssinfo org/data Slide 5

6 which technology to be used? Table 7.8 Reductions of bacteria, viruses and protozoa achieved by household water treatment technologies Slide 6

7 Priciples of membrane filtration Dead end filtration Cross flow filtration ment ISBN 978 ogy for Wastewater Treatm rane Technolo ource: Membr So Slide 7

8 filtration is mostly done by the cake layer raw cake layer water (filtration active) filtrate 1 /1 000 of the diameter of a human hair (MWCO 150 kdalton) Solids (organic, anorganic, bacteria, pathogens, ) Slide 8 membrane typical pore width 20 to 100 nm ( to µm)

9 removal of bacteria, example cholera wikipedia Slide 9 cholera bacteria diameter 300 to 500 nm, length nm ( 2 µm) membrane typical pore width 20 to 100 nm ( to µm)

10 WaterBackpack PAUL designed by DESEE: at DESEE, starting ti 2001, we designed the WaterBackpack called PAUL, a small membrane ultrafiltration (UF) unit membrane area 9.5 m 2 1,200 L/d for 400 people p in emergency and 60 people as permanent supply weight: 23 kg hiht12 height: 1.2 m size: 0.4 m x 0.4 m 6 or 12 units fit on a standard Euro palette 0,80 m max. Slide 10

11 operation principles PAUL dead end filtration ultra low pressure: 0.00 to 0.08 bar (0.04 typical) flat sheet vertically mounted Slide 11

12 Flux decay at standard TMP dead dend filtrationti according to literature, the permeate flow will come to zero (with TMP between 0.3 and 10 bar) feed = raw water decay of filtrate flow rate membrane filtrate = permeate Melin/Rautenbach: Membranverfahren. 3 rd edition ISBN Springer Berlin Heidelberg New York Slide 12

13 Flux stabilization at low TMP Slide 13

14 dead end filtration no sizing effect high h velocities (= forces) along the membrane surface have a sizing effect, leaving higher percentages of small particles on the membrane surface: high h likeliness of pore clogging With ULPUF in dead end mode, force along (parallel to the) membrane is close to Zero! percen ntage of particle size 1 no crossflow (original particle distribution) 2 5 increasing crossflow velocity from 0.3 m/s to 1.5 m/s particle size Rippberger,S.(1993): Berechnungsansätze zur Crossflow Filtration. Chem Ing Tech. h 65, Nr 5, Slide 14

15 Membrane resistance and pore blocking Slide 15 6 ment ISBN ogy for Wastewater Treatm rane Technolo ource: Membr So

16 Low TMP The lower the TMP as the dii driving force for small particles to be dragged into the pores, the lower the occurrence of pore blocking With ultra low TMP, the small particles presumably cannot even pass the cake layer Slide 16

17 cake layer removal dead dend filtration ti is only recommended ddwith very low suspended solids content as can be found in surface waters (in general and during emergencies) cake layer has to be removed somehow but if simple operation is essential, this cannot be done by backflush Slide 17

18 models of cake layer with cross flow Slide 18

19 operation principles PAUL flat sheet vertically mounted td forces at a cake layer particle during filtration F g force of gravity feed F N filtration force permeate F F friction force membrane Slide 19

20 operation principles PAUL forces at a cake layer particle during filtration ti and filling F? force due to turbulence when filling F g force of gravity feed F N filtration force permeate F F friction force membrane Slide 20

21 operation principles PAUL forces at a cake layer particle during filtration ti pause F g force of gravity F S sticky force membrane Slide 21

22 operation principles PAUL forces at a cake layer particle during filtration ti pause and filling F? force due to turbulence when filling F g force of gravity F S sticky force membrane Slide 22

23 operation principles PAUL forces at a cake layer particle during tap closing F g force of gravity plus short term surge when closing tap F S sticky force membrane Slide 23

24 how much water is filtered per day? 1,200 L/d (800 bottles 15Liter 1.5 each) see picture: 1 day production (1.2 tons of water) Slide 24

25 Bacteria removal Log R Reductio on Value LRV Fresenius Fresenius Fresenius Fresenius Fresenius Fresenius e.coli coliforme I.E. e.coli coliforme I.E. ISO ISO ISO ISO ISO ISO PAUL A PAUL A PAUL A PAUL B PAUL B PAUL B Min min 5,301 5,368 4,444 5,672 5,929 5,041 Mittel avg 5,689 5,704 5,092 6,013 6,144 5,245 Max max 6,362 6,415 5,568 6,380 6,431 5,544 analyzed by Institut Fresenius, Göttingen Slide 25

26 Virus removal (Federal Environment Agency UBA) added virusses human adenovirusses analyzed by Federal Environment Agency, Dessau/Roßlau Slide 26

27 Virus removal (Federal Environment Agency UBA) total amount filtered in m³ feed: drinking water analyzed by Federal Environment Agency, Dessau/Roßlau Slide 27

28 How to use in permanet DW supply? top view side view front valve closed valve open tile with valve incl. float, replaces sieve Slide 28

29 How to use in permanet DW supply? raw water tank optional: pre-sieve optional: valve detail tile valve float valve closed top view side view front valve open valve closed valve open tile with valve to be mounted in the filtered water tank at proper height filtered water tank tile with valve incl. float, replaces sieve Slide 29

30 How to use in permanet DW supply? raw water tank optional: pre-sieve optional: valve detail tile valve float valve closed top view side view front valve open valve closed valve open tile with valve to be mounted in the filtered water tank at proper height filtered water tank tile with valve incl. float, replaces sieve Slide 30

31 conclusions advantages of the ULPUF in this application 1. the ULPUF process achieves LRV from 3 up to more than 6 for bacteria as well as for viruses 2. the membrane more or less only serves as a support for the filtrating cake layer this is also exemplified by the high LRV for viruses 3. no cross flow, thus no sizing effect of the cake layer low risk of pore blocking 4. TMP is ultra low, this means driving force of small particles through the cake layer into the pores is very low low risk of pore blocking 5. if EPS occur, they will be transported down to the bottom volume and not be recycled to the membrane surface 6. structure of the cake layer and bacterial activity keep up the cake layer s permeability Low invest, small area: high maintenance & replacement costs high invest, large area: low main tenance & no replacement costs Slide 31

32 and about cost Slide 32

33 more very important facts No spare parts import necessary, as no cartridges tid etc. must be replaced on a regular basis No waste of resources concerning firewood, as boiling the water for disinfection is not necessary anymore Waste minimization, as water will no longer be supplied in plastic bottles Local added value by creation of employment as plant manufacturer/water vendor/plant operator/maintenance worker perfect for micro financing Dramatically reduced dcases of illness, thus less cost due to illness less cost due to inability to work less absence from school = improved educational opportunities Slide 33

34 Uganda Slide 34

35 Tanzania Schaupp Slide 35 Sh Schaupp Schaupp installed March 2012 since then, no more cases of diarrhea, cholera or other waterborne diseases according to locals

36 Peru Slide 36

37 Ecuador Slide 37

38 Ghana Slide 38

39 Nepal Slide 39

40 Nepal Slide 40

41 distribution of PAUL Madagascar: 10 Congo: 17 Malawi: 22 Comoros: 13 Colombia: 8 Cuba: 12 Kenya/ Somalia: 31 Kenya: 9 Cameroon: 9 Malaysia: 4 Mexico: 2 Mongolia: 3 Mozambique: 3 Namibia: 1 Myanmar: 160 Nepal: 217 Nigeria: 5 Niger: 1 Pakistan: 255 1,822 PAUL as of Cambodia: 7 Pakistan: 257 Peru: 10 India: 14 Indonesia: 12 Haiti: 169 Philippines: 165 Vietnam: 118 Guatemala: 1 Senegal: 1 United Kingdom: 2 unknown: 91 Russia: 1 Ghana: 11 Sambia: 1 Switzerland: 1 Zimbabwe: 1 France: 1 Somalia: 11 Eritrea: 5 Ecuador: 5 Dom. Rep.: 1 Chile: 2 Bolivia: 1 Afghanistan: 14 Egypt: 5 Venezuela: 10 Togo: 2 Bulgaria: 1 Bénin: 10 Uganda: 21 Turkey/Syria: 5 Tanzania: 14 St. Lucia: 2 South Sudan: 7 Swaziland: 1 Taiwan: 2 Slide 41

42 thank you very much for your attention! Winner 2011 in the category society Slide 42 Humanity Care Foundation