Dear Elisabeth,
Thank you very much for your feedback about my post. I agree that there are some challenges such as the urine storage, transport and reuse. In this case (mentioned in the paper) we evaluated the urine collection from one waterless urinal which was installed in the context of a university campus, but there was not the urine storage. However in large scale it would be recommended, so it would require space and transport until the places to use it as fertilizer. There are some urban agriculture projects in Sao Paulo, located near the university campus, so this could be an interesting possibility. After the conclusion of this study I showed the results, mainly about the water savings estimates for the department of projects in the university, in order to try to stimulate the replacement of the existing flush urinals by waterless urinals, but so far it has not been done. Here in Brazil it is not easy to find waterless urinal for buying and its price is high in comparison to the conventional urinal. I remember we had the support of a company which sold us the waterless urinal for a low price. There are some malls and airports here in Brazil with waterless urinal in bathrooms but the urine is not collected. I believe maybe in the future it will be possible to implement urine collection in our campus for application as fertilizer in large scale. In my opinion it would be necessary an integrated planning, involving partnerships with researchers in other fields (such as agronomy), institutions and farmers to accelerate this process. Currently I am conducting research about resource recovery in Wastewater Treatment Plants in Sao Paulo area.

Answering your second question, yes, water fee is cheap, but Sao Paulo city and its metropolitan region faced water crisis/problems with water supply recently due to drought in Southeast region. In addition it is a region with high population and low amount of water available per resident. So initiatives for water conservation are important in this area. But unfortunately there is a predominant culture of abundance.
About waterless urinals, thank you for sending the forum about this discussion. I think there is more public acceptance for men waterless urinal than for dry toilets in Brazil, but research should be developed on this topic.

Regards
Mariana

Dear Mariana,

Thanks a lot for posting about your paper here! Great to see that it's open access, too!

The fertilising qualities of urine are well known by now and your study confirmed it again. Usually, a large scale project on urine reuse in cities is hampered by the costs of urine storage, transport and reuse (as it's quite a dilute fertiliser). You said "In future work, we will examine the logistical questions concerning scaling urine collection, transport, and application as fertilizer." Are you hopeful that any upscaling will be possible in your university?
Usually, water and fertiliser are both still to cheap to make this into a financially viable option. But perhaps the situation is different in Sao Paulo?
Waterless urinals are in my opinion great and they have certainly gained a lot of popularily in Germany in the last decade or so.
See also here about waterless urinals on this discussion forum:
forum.susana.org/172-urinals

Regards,
Elisabeth

Dear All,

Following is the article which has been published recently.
´´The sanitation and urban agriculture nexus: urine collection and application as fertilizer in São Paulo, Brazil`` -Journal of Water, Sanitation and Hygiene for Development (September 2017; Vol. 7, No. 3).

washdev.iwaponline.com/content/7/3/455

Abstract:
Separately collected urine is an attractive potential fertilizer because of its high nutrient content, low cost, and inherent linkage of urban wastewater management and peri-urban agriculture. Urine from waterless urinals was applied to corn and lettuce plants to examine the impact of urine application rates and frequency on plant growth and soil parameters. In both corn and lettuce experiments, urine application significantly (p < 0.05) increased growth and leaf production relative to control plants. More frequent applications led to lower soil cation exchange capacities for corn and higher soil nitrogen content for both crops. Based on preliminary implementation calculations, waterless urinals at the University of São Paulo (USP), School of Arts, Sciences, and Humanities campus could lead to over 1,500 m3 of water saved and 360 m3 of urine produced on an annual basis. These experiments and modeling results are discussed in the context of scaling up urban urine collection, transport, and fertilization in São Paulo, Brazil.

Thank you
Best regards

Mariana C. Chrispim
MSc in Environmental Health
PhD student in Sustainability
University of Sao Paulo-Brazil.