WORLD WATER DAY. Why waste water? Bart Van der Bruggen Department of Chemical Engineering KU Leuven (Belgium)

Transcription

1 WORLD WATER DAY Why waste water? Bart Van der Bruggen Department of Chemical Engineering KU Leuven (Belgium)

2 Water and wastewater: one story Water in history Ancient Greece and Rome: aquaducts and fountains 2

3 From wastewater to drinking water Drinkwaterproductie 3

4 Classical wastewater treatment 4

5 Advanced wastewater treatment 5

6 A new approach in wastewater treatment 6

7 Classical drinking water treatment 7

8 Advanced drinking water treatment 8

9 Some trends - wastewater Membrane BioReactor (MBR) for wastewater treatment MBR = challenge: fouling, aeration, cost 9

10 Some trends drinking water Fluidized bed reactor for water softening Cost effective Comfort & economy Water price? 10

11 A trend for drinking water & wastewater Membrane technology as the final solution Intercommunale Waterleidingsmaatschappij van Veurne-Ambacht (IWVA), Koksijde 11

12 A trend for drinking water & wastewater Membranes can retain any pollutant Cost (~desalination); fouling & lifetime; concentrates 12

13 (Waste)water and development First classical methods, then innovation? Are objectives for purification universal? Should standards be the same? Should technologies be the same? Differences due to economical constraints? Which are the additional challenges (compared to developed countries)? 13

14 Starting from classical systems: Hanoi Hanoi 14

15 Low cost solutions? Hanoi 15

16 The low cost, high performance concept Low cost: locally produced Logistic nightmare Business opportunity Technologies are the same Light versions State-of-the-art methods Materials can be different Depends on country/region Design may slightly change Performance plays a role Standards should not be different 16

17 A practical example: adsorption Organic micropollutants: pesticides North Vietnam, Red River Delta Drinking water production: activated carbon Locally made of bamboo and coconut shell Performance close to commercial carbon 17

18 Percent Removed (%) ACBC ACB ACCS Operation time (day) 18

19 Another example: MBR in Vietnam 19

20 Another example: MBR in Vietnam Challenge = cost and logistics Design and assembly: business opportunities Small scale Locally made membranes are missing COST EXPERTISE SUPPLIERS 20

21 Rural and remote areas Business model does not apply Expertise not readily available Other approaches: Constructed wetlands Rainwater harvesting Leasing of technologies 21

22 Constructed wetlands 22

23 Constructed wetlands in Africa Effective in reducing SS, organics (BOD, COD), trace metals and pathogens but less effective in the removal of nutrients Factors that improve the efficiency; hydraulic loading rate, hydraulic residence time, type of substrate, its design, temperature, flow velocity and vegetation type CWs require proper management to remain functional and healthy Regular monitoring of water levels, water flow, biological parameters and water quality is important for CWs to perform well 23

24 Constructed wetlands in Africa Used in a number of African countries such as Tanzania, Kenya, Uganda, Malawi, Zambia, Zimbabwe, Botswana, Ethiopia and Seychelles For secondary treatment of domestic, industrial and acid mine drainage wastewater 23 documented pilot units (horizontal subsurface flow type) were identified in East Africa, mainly in institutions i.e schools, colleges and prisons Data regarding their performances could not be found. Only few (2) have such information. 24

25 CW Region wastewat er type Q Size (M2) scale Type of Plant Pre-treatment (m 3 /d) City abattoir Kampala abattoir 400 exptl Cyperus papyrus Septic tank SEETA HS Mukono full Cyperus papyrus Septic tank Ruaha SS Iringa domestic 20 2 cells of the size 20m x 10m each (serving 1200 people each) full Phragmites mauritianus Septic tank Kleruu TC Iringa domestic 44 baffled system consisting of 4 cells with a total area of 625m 2 full Phragmites mauritianus Septic tank Shinyanga Shinyanga domestic 50 1 cell of size (50mx15m), serving 2500 inmates has planted with full Phragmites mauritianus prison both and Typha latifolia Bariadi prison Shinyanga domestic 50 2 cells with total size of 45mx20m serving 2000 inmates but with no vegetation Malya prison Shinyanga domestic 50 1cell of size 55mx20m serving 3500 inmates full Phragmites mauritianus Chake chake Pemba municipal full Macrophytes native to the Anaerobic pond area MUWSA Kilimanjaro municipal full Phragmites mauritianus WSP Kibo Paper Kilimanjaro industrial Baffled consisting of 3cells of total size 128mx42m full Phragmites mauritianus. BIL Arusha agroprocessing 400 full Cyperus papyrus Anaerobic pond Shimo la Tewa Mombasa domestic full North Mara Musoma AMD 5 15 exptl Phragmites mauritianus IRUWASA Iringa municipal full Phragmites mauritianus WSP Mahe Seychelles domestic full Modjo Addis ababa tannery full Phragmites mauritianus Miyuji Dodoma domestic full cattails China paper Kilimanjaro paper recycling full Phragmites mauritianus MORUWASA Morogoro municipal exptl Phragmites mauritianus WSP Chamazi community DSM domestic full Phragmites mauritianus TPCC DSM domestic exptl cattails Iringa Girls SS Iringa domestic full Phragmites mauritianus septic tank

26 Challenges of CWs in East Africa Most of the established HSSFCW systems are facing problems ranging mainly from clogging overland flow dying of wetland plants and poor effluent quality Lack of operational and maintenance guidelines are main causes of the mentioned problems Poor pretreatment of wastewater influent introduces SS to the system hence contributes largely to clogging of CWs together with the biological growth

27 Rainwater harvesting Rainwater is perceived as one of the alternative water sources especially for developing countries Limitations: o o o o Negative social perceptions Variable quantity Low harvestable quantities (low rainfall, small roof sizes, small reservoirs) Water quality depends on design and maintenance 27

28 Study area: Kabarole district - Uganda Source: PROTOS (2013) 28

29 change in monthly rainfall Predicted change in rainfall - Uganda 60% Rainfall Predictions due to Climate Change for Mpanga Catchment 40% 20% 0% -20% Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec -40% -60% RCP 4.5 A1b-ECHAM A1b-HadCM3 A2-ECHAM A2-HadCM3 B1-ECHAM B1-HadCM3 Average of all scenario The period from April to September is likely to be dryer than what it used to be, whereas October to February will tend to be wetter

30 Evaluation of water quality Water source # % with E.coli = 0 % with E.coli 50 Median E.coli count Median Turbidity Median ph Median DO Borehole Formal rainwater harvesting system Informal rainwater harvesting system Gravity flow water scheme Protected spring Tap water from NWSC Unprotected well Total 140

31 Leasing of technologies 31

32 Fluoride concentration profile in drinking water sources of Ethiopia 32

33 Option to overcome the problem Point-of-Use Under the Sink Adsorption using locally available materials most effective at decentralized level

34 Pilot study in Jimma, Ethiopia Design of a simple but effective treatment method Limitation: removal capacity Pot filter for point-of-use water treatment 34

35 Logistic approach for implementation of Point of Use Customer outreach Responsibilities for stakeholders will be assigned Scheduling and record keeping, spare parts inventory will be considered regeneration and waste disposal will be the responsibility of household members and assigned stakeholder/s (leasing system) customers could purchase and install a POU treatment device(s) a customer contact line will be created 35

36 Conclusions (Waste)water technologies should not be different in developing countries as the performance should be the same Expertise is necessary: collaboration pays off when linked to capacity building A local approach helps to overcome logistic problems Recognize business opportunities, and stimulate this 36