New sanitation concepts where black water (BW - toilet wastewater) and grey water (GW - shower/washing wastewater) are separated at source, are focused on conserving the richness present in our wastewater in a smaller volume which makes them easier to recover. The Netherlands Institute of Ecology (NIOO-KNAW) in the Netherlands, has implemented such source separated system in its new building. The BW is vacuum collected using only 1L of water per flush and then treated in a UASB (upflow anaerobic sludge blanket), where the carbon is converted into biogas – a green energy source. The remaining effluent, known as anaerobically treated black water (AnBW), contains the major part of the nutrients. One of these nutrients is phosphorus, which, at current extraction rate, will be depleted in the coming century (Cordell et al., 2011). Of all domestic wastewater produced in a household, urine has 40% of phosphorus and 69% of nitrogen, while faeces has 28% of phosphorus and 13% of nitrogen (Kujawa-Roeleveld & Zeeman, 2006). When able to recover that phosphorus, human excreta could supply 22% of the world phosphorus demand (Mihelcic et al., 2011).
A very promising alternative to recover phosphorus, and nitrogen at the same time, is by microalgae growth. Microalgae are becoming increasingly interesting as renewable energy sources due to their fast growth and non-competitive nature with regard to food production. When sufficient light and carbon dioxide are supplied, microalgae biomass production and nutrient uptake are high. The algae biomass could be directly used as a fertilizer, therefore returning the nutrients back to the soil to grow crops and therefore closing the nutrient cycle.
From the beginning of 2018, NIOO-KNAW, the University of Amsterdam (UvA) and Wageningen University (WUR) will help Ecodorp Boekel with the implementation of a decentralized sanitation system focused on closing the nutrient cycle from black water on-site. The acceptance of this innovative system will be tested by the village inhabitants and adaptations will be put in place when needed.
This is a really practical project where students are expected to work independently and be lab proficient. Creativity and trouble-shooting skills are highly appreciated. We accept HBO, BSc and MSc students for periods of a minimum of 4 months.
In the practical experiments, we look at:
Cordell, D., Rosemarin, A., Schröder, J.J., Smit, A.L. 2011. Towards global phosphorus security: A systems framework for phosphorus recovery and reuse options. Chemosphere, 84(6), 747-758.
Kujawa-Roeleveld, K., Zeeman, G. 2006. Anaerobic Treatment in Decentralised and Source-Separation-Based Sanitation Concepts. Reviews in Environmental Science and Biotechnology, 5(1), 115-139.
Mihelcic, J.R., Fry, L.M., Shaw, R. 2011. Global potential of phosphorus recovery from human urine and feces. Chemosphere, 84(6), 832-839.