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

Partners Eva Kocbek Peter Mawioo

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 www.nelsonmacneil.com

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. 2008 Sep; 74(17): 5267–5275.

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.

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 ↓

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

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. http://wiki.anton-paar.com

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 12.25 cm). electric energy -> kinetic energy ->heat http://wiki.anton-paar.com

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 http://wiki.anton-paar.com More rapid heating will occur for the tap compared to distilled water

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.

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).

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

Message on MW heating Internal heating -> rapid Selected heating -> high energy efficiency Heating uniformity by stirrer/turntable/belt conveyer Figures: http://www.microdenshi.co.jp/en/microwave/

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. 2016 Apr 1; 548-549: 72–81

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

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

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

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

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

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

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