Simultaneous inactivation of antibiotic-resistant bacteria and degradation of antibiotic-resistant genes in alkalised human urine.

The coexistence of pharmaceuticals and microorganisms in source separated urine poses a risk for the development of antimicrobial resistance (AMR), especially when urine-based fertilizers are applied to soils. While prior studies have investigated pathogen inactivation in source-separated wastewater matrices, few have evaluated the simultaneous fate of antibiotic-resistant bacteria (ARBs) and their corresponding resistance genes (ARGs) in real urine matrices, particularly under alkaline conditions. Here, we studied the inactivation of β-lactamase-producing and vancomycin-resistant and the degradation of their respective ARGs ( and A) in alkalized, unhydrolyzed urine (pH 10.

Partitioning behavior and crystallization of urea, salts and water during stepwise dehydration of acidified human urine by evaporation.

This study evaluated the stepwise evaporative concentration of acidified human urine, focusing on dehydration dynamics, crystallization sequence, and the partitioning of major constituents between liquid and solid phases. Unhydrolyzed urine, stabilized with sulfuric acid, was concentrated by convective evaporation, achieving concentration factors (CF) of up to 30 at 20 °C and 43 at 70 °C. Water activity (a) was a reliable indicator for monitoring urine dehydration progress, with a critical threshold of 0.

Consequential life cycle assessment of urban source-separating sanitation systems complementing centralized wastewater treatment in Lund, Sweden.

This study examined various source-separating sanitation systems to evaluate their environmental performance, providing decision-makers with insights for selecting an appropriate system for a newly developed neighborhood in Sweden. A full consequential LCA was conducted to account for resource recovery and substitution. The local wastewater treatment plant WWTP was modeled as a reference.

Circular fertilisers combining dehydrated human urine and organic wastes can fulfil the macronutrient demand of 15 major crops.

This study evaluated the potential for combining dehydrated human urine with one other form of organic waste to create circular fertilisers tailored to meet the macronutrient demand of 15 major crops cultivated globally. Through a reverse blending modelling approach, data on 359 different organic wastes were used to identify 38 fertiliser blends. Materials found to be particularly suitable as blending materials were various biochars and ashes, due to their low nitrogen and high phosphorus and/or potassium content, and byproduct concentrates, due to their high phosphorus content, since the nitrogen content of human urine is disproportionately higher than its phosphorus content.

Selective degradation of endogenous organic metabolites in acidified fresh human urine using sulphate radical-based advanced oxidation.

The human urine metabolome is complex, containing a wide range of organic metabolites that affect treatment of urine collected in resource-oriented sanitation systems. In this study, an advanced oxidation process involving heat-activated peroxydisulphate was used to selectively oxidise organic metabolites in urine over urea and chloride. Initial experiments evaluated optimal conditions (peroxydisulphate dose, temperature, time, pH) for activation of peroxydisulphate in unconcentrated, non-hydrolysed synthetic urine and real urine acidified to pH 3.

Concomitant urea stabilization and phosphorus recovery from source-separated fresh urine in magnesium anode-based peroxide-producing electrochemical cells.

In this study, we investigated the recovery of nitrogen (N) and phosphorus (P) from fresh source-separated urine with a novel electrochemical cell equipped with a magnesium (Mg) anode and carbon-based gas-diffusion cathode. Recovery of P, which exists primarily as phosphate (PO) in urine, was achieved through pH-driven precipitation. Maximizing N recovery requires simultaneous approaches to address urea and ammonia (NH).

Degradation of 75 organic micropollutants in fresh human urine and water by UV advanced oxidation process.

In household wastewater, a large proportion of organic micropollutants (OMPs) load is attributed to human urine. OMPs could pose a risk to human and environmental health when urine collected in source-separating sanitation systems is recycled as crop fertiliser. This study evaluated degradation of 75 OMPs in human urine treated by a UV-based advanced oxidation process.

Human urine: A novel source of phosphorus for vivianite production.

Human urine contributes up to 50 % of the phosphorus load in domestic wastewater. Decentralized sanitation systems that separately collect urine provide an opportunity to recover this phosphorus. In this study, we leveraged the unique and complex chemistry of urine in favor of recovering phosphorus as vivianite.

Factors influencing the recovery of organic nitrogen from fresh human urine dosed with organic/inorganic acids and concentrated by evaporation in ambient conditions.

To feed the world without transgressing regional and planetary boundaries for nitrogen and phosphorus, one promising strategy is to return nutrients present in domestic wastewater to farmland. This study tested a novel approach for producing bio-based solid fertilisers by concentrating source-separated human urine through acidification and dehydration. Thermodynamic simulations and laboratory experiments were conducted to evaluate changes in chemistry of real fresh urine dosed and dehydrated using two different organic and inorganic acids.

Poor awareness and attitudes to sanitation servicing can impede China's Rural Toilet Revolution: Evidence from Western China.

The ongoing Toilet Revolution in China offers an opportunity to improve sanitation in rural areas by introducing new approaches, such as urine source separation, that can contribute to achieving SDG6. However, few studies have systematically assessed the social acceptability of managing human excreta collected in new sanitation systems. Therefore, in this study we performed face-to-face interviews with 414 local residents from 13 villages across three provinces in western China, to analyze the current situation and attitudes to possible changes in the rural sanitation service chain.

Attitudes of food consumers at universities towards recycling human urine as crop fertiliser: A multinational survey dataset.

We present here a data set generated from a multinational survey on opinions of university community members on the prospect of consuming food grown with human urine as fertiliser and about their urine recycling perceptions in general. The data set comprises answers from 3,763 university community members (students, faculty/researchers, and staff) from 20 universities in 16 countries and includes demographic variables (age bracket, gender, type of settlement of origin, academic discipline, and role in the university). Questions were designed based on Ajzen's theory of planned behaviour to elicit information about three components of behavioural intention-attitudes, subjective norms, and perceived behavioural control.

Willingness among food consumers to recycle human urine as crop fertiliser: Evidence from a multinational survey.

Source-separating sanitation systems offer the possibility of recycling nutrients present in wastewater as crop fertilisers. Thereby, they can reduce agriculture's impacts on global sources, sinks, and cycles for nitrogen and phosphorous, as well as their associated environmental costs. However, it has been broadly assumed that people would be reluctant to perform the new sanitation behaviours that are necessary for implementing such systems in practice.

Alkaline dehydration of source-separated fresh human urine: Preliminary insights into using different dehydration temperature and media.

For sanitation systems aiming at recycling nutrients, separately collecting urine at source is desirable as urine contains most of the nutrients in wastewater. However, reducing the volume of the collected urine and recovering majority of its nutrients is necessary, as this improves the transportability and the end-application of urine-based fertilisers. In this study, we present an innovative method, alkaline dehydration, for treating fresh human urine into a nutrient-rich dry solid.

Hygiene aspect of treating human urine by alkaline dehydration.

Over four billion people are discharging untreated human excreta into the environment without any prior treatment, causing eutrophication and spreading disease. The most nutrient rich fraction is the urine. Urine can be collected separately and dehydrated in an alkaline bed producing a nutrient rich fertiliser.

What do consumers think about recycling human urine as fertiliser? Perceptions and attitudes of a university community in South India.

Sanitation systems based on source separation and valorisation of human urine can improve the environmental sustainability of wastewater management. Yet, the social acceptability of such new, resource-oriented sanitation practices have not been assessed systematically. We attempt to address this research gap by reporting the findings of a survey conducted at a South Indian university that evaluated support for urine recycling among 1252 Indian consumers.

Alkaline dehydration of anion-exchanged human urine: Volume reduction, nutrient recovery and process optimisation.

In urine-separating sanitation systems, bacterial urease enzymes can hydrolyse urea to ammonia during the pipe transport and storage of urine. The present study investigated whether it was possible to reduce the urine volume without losing the nitrogen as ammonia. A method for stabilising the urine prior to dehydration was developed.

Farmer attitudes and perceptions to the re-use of fertiliser products from resource-oriented sanitation systems - The case of Vellore, South India.

Relatively little research has been conducted to date on farmer attitudes towards the use of fertilisers from resource-oriented sanitation systems. This study employed a psycho-sociological approach to identify factors that encourage, or discourage, negative and positive attitudes to human waste recycling among farmers in southern India. A survey involving face-to-face interviews was performed with 120 randomly sampled farmers, taking into account the following factors: gender, age, religion, caste, type of farming, farm size, annual income and farming history.