1. Improving WASH for urban settings under stress of migrants
Integrated mobile approach for faecal sludge treatment using microwave irradiation
Improving WASH for urban settings under stress of migrants
C.M. Hooijmansa, E. Kocbeka, H.A. Garciaa, Z. Dalalab, M. Aladdousb, D. Brdjanovica
a Department of EEWT, UNESCO-IHE, The Netherlands
b School of Natural Resources Engineering and Management, GJU, Jordan

2. Partners
Eva Kocbek
Peter Mawioo

3. Context: emergency sanitation
Heavy usage of onsite sanitation facilities in refugee camps or cities with a high influx of refugees
Rapid accumulation of large amounts of fresh FS in pit latrines/ septic tanks which should be frequently emptied
FS contains large amounts of pathogens, uncontrolled disposal might jeopardize human health and pollute the scarce water resources
SDG’s: alternative technologies to fill the gap that business as usual technologies have not been able to address

4. Disease(s) and/or symptoms
Principal human pathogenic bacteria identified in municipal
wastewater and sewage sludge
Pathogen
Disease(s) and/or symptoms
Salmonella spp.
Salmonellosis, typhoid
Shigella spp.
Bacillary dysentery
Escherichia coli (enteropathogenic strains)
Gastroenteritis
Pseudomonas aeruginosa
Otitis externa, skin infections (opportunistic pathogen)
Yersinia enterocolitica
Acute gastroenteritis
Clostridium perfringens
Gastroenteritis (food poisoning)
Clostridium botulinum
Botulism
Bacillus anthracis
Anthrax
Listeria monocytogenes
Listeriosis
Vibrio cholera
Cholera
Mycobacterium spp.
Leprosy, tuberculosis
Leptospira spp.
Leptospirosis
Campylobacter spp.
Staphylococcus
Impetigo, wound infections, food poisoning
Streptococcus
Sore throat, necrotizing fasciitis, scarlet fever
Appl Environ Microbiol Sep; 74(17): 5267–5275.

5. Emergency sanitation
“In many emergency situations access to adequate sanitation is one of the strongest determinants of survival. At times, humanitarian actors lack sufficient capacity to ensure affected people have access to adequate sanitation. Unlike increased availability of emergency water supply options, only few alternatives for sanitation have been developed over the last thirty years.”
=> Need for innovation
Emergency Sanitation Workshop at U-IHE, 2012, UNHCR, IFRC, NLRC, Oxfam.

6. What to do with FS to protect water resources and health?
Sanitization
Pathogen kill/inactivation; affected by heat, moisture content, pH.
Relation between temperature and time: ↑ T, time
Liquid sludge: heat transfer by mixing*1
More solid sludge: heat transfer by air flow*2
Liquid sludge: lime addition
Especially helminth eggs are a problem to inactivate…….
MicroWave heating technology
*1Norwegian and Swedish Red Cross and partners – A-Aqua: Hygieniser100 and VacuSan
*2LaDePa South Africa ↓

7. MW based reactor system
NLRC is working on a FS desludging unit for emptying pit latrines
Microwave (MW) based reactor system for FS treatment
Compact and portable

8. MW heating
Microwaves… … help to minimize wall effects since the vessel wall is not directly heated. … provide a more energy efficient way of heating (direct “in-core” heating). … allow faster heating of a reaction mixture
Microwave heating of gases and solids…
… is hardly possible! Gases cannot be heated under microwave irradiation, since the distance between the rotating molecules is too wide. Similarly, solid materials like ice are (nearly) microwave transparent, since the water dipoles are bound in the crystal lattice and cannot move as freely as in the liquid state. However, some conductive solid materials, like silicon carbide, where electrons can move freely, are excellent microwave absorbers and therefore heat very quickly.

9. MW heating electric energy -> kinetic energy ->heat
All domestic “kitchen” microwave ovens as well as commercially available dedicated microwave reactors :frequency of 2.45 GHz (corresponding to a wavelength of cm).
electric energy -> kinetic energy ->heat

10. Microwave Dielectric Heating
(a) Dipolar polarization:
Microwave field is oscillating, the dipoles in the field align causing rotation: heat energy.
(b) Ionic conduction:
Dissolved charged particles (usually ions) oscillate back and forth under the influence of changing electric field: heat energy. .
Dipolar polarization: Substance to be able to generate heat when irradiated with microwaves must be a dipole, i.e. its molecular structure must be partly negatively and partly positively charged. Since the microwave field is oscillating, the dipoles in the field align to the oscillating field. This alignment causes rotation, which results in friction and ultimately in heat energy.
Ionic conduction (see Figure 3) During ionic conduction, dissolved (completely) charged particles (usually ions) oscillate back and forth under the influence of microwave irradiation. This oscillation causes collisions of the charged particles with neighboring molecules or atoms, which are ultimately responsible for creating heat energy. As an example: if equal amounts of distilled water and tap water are heated by microwave irradiation, more rapid heating will occur for the tap water because of its ionic content in addition to the dipolar rotation of water molecules
More rapid heating will occur for the tap compared to distilled water

11. Dielectric properties
Material must have certain dielectric properties in order to be heated in the microwave field: expressed by dielectric power factor:
𝑡𝑎𝑛𝛿= 𝜀 " 𝜀 ′ = 𝑑𝑖𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝑙𝑜𝑠𝑠 𝑓𝑎𝑐𝑡𝑜𝑟 𝑑𝑖𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡
Dielectric loss factor = depicts the amount of input MW energy that is lost by being converted (dissipated) to heat within the material
Dielectric constant = ability of material to store MW energy as it passes through
So: materials with high dielectric loss factors are easily heated by MW energy. A low loss material can be heated indirectly by MW energy by blending with a high loss material (i.e. MW facilitator e.g. char). The MW first heats the facilitator which then heats the low loss material.

12. Very specific heating of material
FS: contain high amounts of dipolar molecules such as water and organic complexes: good candidates for the MW dielectric heating; .
A low loss material can be heated indirectly by MW energy by blending with a high loss material (i.e. MW facilitator e.g. char).
Interaction of different materials with microwaves:
i) electrical conductors (e.g. metals)
ii) absorbing materials (e.g. water) and
iii) insulation materials (e.g. Teflon, glass, quartz).

13. Results of laboratory tests with sewage sludge
Temperature evolution during microwave treatment of samples of wet sewage as received; and mixed with 5 wt% of the char obtained in a previous run
J.A. Menendez et.al, Fuel Processing Technology, Volume 91, Issue 1, January 2010, Pages 1–8

14. Message on MW heating Internal heating -> rapid
Selected heating -> high energy efficiency
Heating uniformity by stirrer/turntable/belt conveyer
Figures:

15. Results of laboratory tests with faecal sludge
Rapid temperature evolution
Pathogen inactivation
Weight reduction
Conclusion:
Efficient way of pathogen kill off due to rapid heating, and promising for FS drying
P. Mawio et.al, Sci Tota.l Environ Apr 1; : 72–81

16. Results of pilot tests with various type of sludge
Microwave reactor unit
Sample: 4 kg (centrifuged) WAS, SS and FS
Microwave power: 3.4 kW
Exposure time: 30, 60, 90, 120 and 240 min

17. Dried sludges
FS 90 % DS
CWAS 80 % DS
SS 90 % DS
WAS 90 % DS

18. Calorific value of various biomass
Results of pilot tests with various type of sludge
Results of pilot tests with various type of sludge
Dry WAS
80 % DS
Calorific value of various biomass
Dry centrifuged WAS
90 % DS

19. Container system Dielectric properties of sludge
Calorific value of sludge
Pathogenic indicators
Energy consumption per unit
Alternative energy source

20. Application of renewable energy
Testing of system at pilot site location
Faculty, staff and students

21. WAJ:
Standards for wastewater, sludge reuse
Stakeholder involvement and perception more critical than standards
Interested in application of complete system once ready after research stage
Miyahuna:
Interested in technology for application
Alternative technology for unique and/or dispersed situations
Potential end-users

22. Further research with focus on application in Jordan
Further development together with partners
Optimization of the system in Jordan with German Jordanian University, Water Authority, Miyahuna
Action research on user acceptance
Outcome: experience and application of a promising technology to de- sludge and treat on-site FS for Jordan, increased local WASH capacity
The MW system will remain for further use with the partners in Jordan