RESUMEN
A No Mix sanitation system was installed in a dormitory at the University of Can Tho in Vietnam, with the objective of recycling nutrients from source separated urine. This paper presents a pilot scale evaporation technology, and investigates the feasibility of recovering nitrogen and phosphorus from human urine by solar still for use as fertilizer. After 26 days of sun exposure, 360 g of solid fertilizer material was recovered from 50 L undiluted urine. This urine-derived fertilizer was mainly composed of sodium chloride, and had phosphorus and nitrogen contents of almost 2%. When tested with maize and ryegrass, the urine fertilizer led to biomass yields and phosphorus and nitrogen uptakes comparable to those induced by a commercial mineral fertilizer. Urine acidification with sulfuric or phosphoric acid prior treatment reduced nitrogen losses, improved the nutrient content of the generated fertilizers, and induced higher biomass yields and nitrogen and phosphorus uptakes than the commercial mineral fertilizer. However, acidification is not recommended in developing countries due to additional costs and handling risks. The fate of micropollutants and the possibility of separating sodium chloride from other beneficial nutrients require further investigation.
Asunto(s)
Desecación/métodos , Fertilizantes , Nitrógeno/aislamiento & purificación , Fósforo/aislamiento & purificación , Luz Solar , Orina/química , Análisis de Varianza , Biomasa , Humanos , Lolium/efectos de los fármacos , Lolium/crecimiento & desarrollo , Nitrógeno/farmacología , Fósforo/farmacología , Proyectos Piloto , Vietnam , Zea mays/efectos de los fármacos , Zea mays/crecimiento & desarrolloRESUMEN
Urine contains a considerable amount of nutrients and potentially could be used as supplement commercial mineral fertilizer; however, it carries risk of contamination. The effect of urine storage as a simple treatment method was examined under tropical conditions. Initial concentrations of total coliforms (2.3 x 10(5) CFU/100 mL), E. coli (<1.0 x 10(4) CFU/100 mL), and Salmonella sp. were less than detection limit after four weeks. Open storage led to nitrogen losses of 90%, whereas closed storage containers retained 93% of total nitrogen. Under storage, the N:P ratio of 8:1 in fresh urine changed to 14:1 in the supernatant and to 1:12 in the precipitate, and 100% of magnesium and 96% of calcium was precipitated. A model showed that, depending on plant requirements, using the mixture of supernatant and precipitate as fertilizer for crops such as cassava was reasonable. To fertilize crops such as rice, however, additional P and K was needed. The nutrient-based flux of heavy metals to soils was negligible.
Asunto(s)
Fertilizantes/análisis , Orina/química , Orina/microbiología , Alemania , Humanos , Metales Pesados/química , Factores de Tiempo , VietnamRESUMEN
BACKGROUND: Human African trypanosomiasis (HAT; sleeping sickness) caused by Trypanosoma brucei gambiense is a fatal disease. Current treatment options for patients with second-stage disease are toxic, ineffective, or impractical. We assessed the efficacy and safety of nifurtimox-eflornithine combination therapy (NECT) for second-stage disease compared with the standard eflornithine regimen. METHODS: A multicentre, randomised, open-label, active control, phase III, non-inferiority trial was done at four HAT treatment centres in the Republic of the Congo and the Democratic Republic of the Congo. Patients aged 15 years or older with confirmed second-stage T b gambiense infection were randomly assigned by computer-generated randomisation sequence to receive intravenous eflornithine (400 mg/kg per day, every 6 h; n=144) for 14 days or intravenous eflornithine (400 mg/kg per day, every 12 h) for 7 days with oral nifurtimox (15 mg/kg per day, every 8 h) for 10 days (NECT; n=143). The primary endpoint was cure (defined as absence of trypanosomes in body fluids and a leucocyte count
Asunto(s)
Eflornitina/uso terapéutico , Nifurtimox/uso terapéutico , Tripanocidas/uso terapéutico , Trypanosoma brucei gambiense , Tripanosomiasis Africana/tratamiento farmacológico , Administración Oral , Adulto , Animales , Congo/epidemiología , República Democrática del Congo/epidemiología , Esquema de Medicación , Quimioterapia Combinada , Eflornitina/efectos adversos , Femenino , Fiebre/inducido químicamente , Estudios de Seguimiento , Humanos , Infecciones/inducido químicamente , Infusiones Intravenosas , Estimación de Kaplan-Meier , Masculino , Nifurtimox/efectos adversos , Seguridad , Convulsiones/inducido químicamente , Resultado del Tratamiento , Tripanocidas/efectos adversos , Tripanosomiasis Africana/diagnóstico , Tripanosomiasis Africana/epidemiologíaRESUMEN
The plant nutrients consumed in human society today are lost through the established wastewater treatment systems in industrialised countries as well as via insufficient or non-existent handling of sewage in the developing world. New sanitation systems have been designated to overcome this failure. The source separated wastewater streams collected within these systems contain a high nutrient content, and can be used as fertiliser as well as soil conditioner after appropriate storage and/or treatment. Application in agriculture with existing techniques is feasible. However, pathogens and pharmaceuticals contained in these fertiliser types are a potential hazard. Nevertheless, storage and appropriate treatment can minimise the risks. The products deriving from these systems have a high potential to preserve available plant nutrient resources and deficiencies in agriculture as well as being able to substitute synthetic plant nutrients and at the same time prevent unwanted environmental nutrient over-enrichment.
Asunto(s)
Fertilizantes , Saneamiento , Heces , Metales Pesados/análisisRESUMEN
BACKGROUND: Human African trypanosomiasis caused by Trypanosoma brucei gambiense is a fatal disease. Current treatment options for patients with second-stage disease are either highly toxic or impracticable in field conditions. We compared the efficacy and safety of the nifurtimox-eflornithine drug combination with the standard eflornithine regimen for the treatment of second-stage disease. METHODS: A randomized, open-label, active-control, phase III clinical trial comparing 2 arms was conducted at the Sleeping Sickness Treatment Center, which was run by Medecins Sans Frontieres, in Nkayi, Bouenza Province, Republic of Congo. Patients were screened for inclusion and randomly assigned to receive eflornithine alone (400 mg/kg per day given intravenously every 6 h for 14 days) or eflornithine (400 mg/kg per day given intravenously every 12 h for 7 days) plus nifurtimox (15 mg/kg per day given orally every 8 h for 10 days). Patients were observed for 18 months. The study's outcomes were cure and adverse events attributable to treatment. RESULTS: A total of 103 patients with second-stage disease were enrolled. Cure rates were 94.1% for the eflornithine group and 96.2% for the nifurtimox-eflornithine group. Drug reactions were frequent in both arms, and severe reactions affected 25.5% of patients in the eflornithine group and 9.6% of those in the nifurtimox-eflornithine group, resulting in 2 and 1 treatment suspensions, respectively. There was 1 death in the eflornithine arm and no deaths in the nifurtimox-eflornithine arm. CONCLUSIONS: The nifurtimox-eflornithine combination appears to be a promising first-line therapy for second-stage sleeping sickness. If our findings are corroborated by ongoing findings from additional sites (a multicenter extension of this study), the new nifurtimox-eflornithine combination therapy will mark a major and multifaceted advance over current therapies.