Nitrogen removal from swine wastewater by combining treated effluent with raw manure

Effluents from swine raising can be harmful to the environment if not correctly managed. Nitrogen (N) is usually the main element present at high concentrations in the effluent. Since the use as biofertilizer is not always a feasible alternative, the treatment of swine wastewater is necessary. Variations in N species and water solubility make the treatment difficult and expensive. Additional N removal at low cost via denitrification may be possible by recirculating nitrified effluent in the barns. In this study, raw manure (RM) was homogenized with treated effluent (TE) at RM/(RM + TE) ratios of 1.0, 0.9, 0.8, 0.7, 0.6, 0.5 and 0 in order to simulate the effect of reused water on swine wastewater nitrogen removal. Samples were collected daily during four days and analyzed for pH, oxidation-reduction potential, NH4-N, NO2-N, NO3-N and chemical oxidation demand. The oxidized nitrogen (NOx-N) half-life degradation was estimated using linear regression. NOx-N species half-life less than one day was obtained when treated effluent was combined and thoroughly homogenized with raw manure. It is suggested that combining raw manure with treated effluent (e.g. water reuse) can be a simple and cost-effective strategy to remove nitrogen from swine wastewaters

Recovery of ammonia from anaerobically digested manure using gas-permeable membranes

ABSTRACT Nitrogen (N) can be recovered from different types of wastewaters. Among these wastewaters, anaerobically digested swine manure (digestate) has the highest N content in ammonia form (NH3). It is desirable to reduce N in digestate effluents to safely incorporate them in arable soil in N vulnerable zones (NVZ) and to mitigate NH3 emissions during N land application. Additional benefit is to minimize inhibition of the anaerobic process by removing NH3 during the anaerobic digestion process. This work aimed to apply the gas-permeable membrane technology to evaluate ammonia (NH3) recovery from high-ammonia digested swine manure. Anaerobically digested swine manure with NH4+ content of 4,293 mg N L−1 was reduced by 91 % (to 381 mg N L−1) during the 32-day experiment. Although the results showed a total N recovery efficiency of 71 %, it is possible to increase this recovery efficiency to > 90 % by adjusting the area of the membrane system to match the high free ammonia concentration (FA) in digested swine manure. Moreover, final digestate pH and alkalinity were kept around 8.1 and 8,923 mgCaCO3 L−1, which are convenient for the anaerobic process or incorporation in arable soil when the process is finished

Partial nitritation of swine wastewater in view of its coupling with the anammox process

Partial nitritation (PN) of swine wastewater was investigated in a sequencing batch reactor (SBR) using a high performance nitrifying sludge (HPNS). Characteristics of the wastewater used were low content of biodegradable organic carbon and high alkalinity-to-ammonium ratio. Process temperature was 32°C. Target oxidation of ammonium nitrogen (NH4-N) to nitrite nitrogen (NO2-N) was 57% (1.32 g NO2-N g-1 NH4-N), which corresponds with the stoichiometry of the anammox reaction. This target was successfullly achieved just by controlling the inflow rate and corresponding N loading rate (NLR). An average NLR of 1.47 g NH4-N L-1 d- 1 was applied to the PN-SBR during a period of 70 days. The NO2-N production rate obtained was 0.91 g L- 1 d-1. No nitrate was produced. The PN effluent contained 1.38 g NO2-N g-1 NH4-N, which was within 5% of the target ratio. Under steady state conditions, the pH was shown as a good indicator of the PN process performance. Furthermore, in a second SBR the anammox process was effectively applied to the PN effluent attaining an N conversion rate of 0.36 g N L- 1 h-1 (14.3 mg N g-1 VSS h-1).Postprint (published version

Anammox treatment of swine wastewater using immobilized technology

ppropriate land application of manure nitrogen at agronomic rates must be assured in order to preserve environmental quality of agricultural ecosystems, atmosphere, and water resources. When land is limiting, the combined bioprocess of nitrification-denitrification (NDN) has often been considered for the removal of nitrogen, implying the conversion of ammoniumPostprint (published version

Control de patógenos en los purines de cerdo mediante el tratamiento del nitrógeno y del fósforo

Últimamente ha aumentado mucho la preocupación por la posible contaminación de las aguas, los alimentos y el aire debido a los patógenos existentes en el estiércol, los subproductos del estiércol y los bioaerosoles. Hemos valorado la reducción de los patógenos en un sistema de tratamiento de purines de varias fases, la primera de las cuales consiste en separar los sólidos y los líquidos mediante el uso de polímero, seguida de una fase de eliminación biológica del nitrógeno (N) por medio de la nitrificación y la denitrificación, para a continuación en una última fase extraer el fósforo (P) mediante una precipitación en medio alcalino. Cada fase del sistema de tratamiento ha sido evaluada en relación con su efectividad en la eliminación de patógenos e indicadores de patógenos, realizándolo mediante el recuento de coliformes totales y fecales, enterococos y salmonellas utilizando medios nutritivos selectivos y diferenciales. Nuestros resultados indican que el tratamiento de nitrificación/denitrificación es sumamente eficiente para reducir los patógenos en los purines de cerdo y que la fase de eliminación del fósforo por medio de la precipitación alcalina con calcio produce un efluente higienizado que puede resultar importante por razones de bioseguridad

Partial nitritation of swine wastewater in view of its coupling with the anammox process

Partial nitritation (PN) of swine wastewater was investigated in a sequencing batch reactor (SBR) using a high performance nitrifying sludge (HPNS). Characteristics of the wastewater used were low content of biodegradable organic carbon and high alkalinity-to-ammonium ratio. Process temperature was 32°C. Target oxidation of ammonium nitrogen (NH4-N) to nitrite nitrogen (NO2-N) was 57% (1.32 g NO2-N g-1 NH4-N), which corresponds with the stoichiometry of the anammox reaction. This target was successfullly achieved just by controlling the inflow rate and corresponding N loading rate (NLR). An average NLR of 1.47 g NH4-N L-1 d- 1 was applied to the PN-SBR during a period of 70 days. The NO2-N production rate obtained was 0.91 g L- 1 d-1. No nitrate was produced. The PN effluent contained 1.38 g NO2-N g-1 NH4-N, which was within 5% of the target ratio. Under steady state conditions, the pH was shown as a good indicator of the PN process performance. Furthermore, in a second SBR the anammox process was effectively applied to the PN effluent attaining an N conversion rate of 0.36 g N L- 1 h-1 (14.3 mg N g-1 VSS h-1)

Control de patógenos en los purines de cerdo mediante el tratamiento del nitrógeno y del fósforo

Últimamente ha aumentado mucho la preocupación por la posible contaminación de las aguas, los alimentos y el aire debido a los patógenos existentes en el estiércol, los subproductos del estiércol y los bioaerosoles. Hemos valorado la reducción de los patógenos en un sistema de tratamiento de purines de varias fases, la primera de las cuales consiste en separar los sólidos y los líquidos mediante el uso de polímero, seguida de una fase de eliminación biológica del nitrógeno (N) por medio de la nitrificación y la denitrificación, para a continuación en una última fase extraer el fósforo (P) mediante una precipitación en medio alcalino. Cada fase del sistema de tratamiento ha sido evaluada en relación con su efectividad en la eliminación de patógenos e indicadores de patógenos, realizándolo mediante el recuento de coliformes totales y fecales, enterococos y salmonellas utilizando medios nutritivos selectivos y diferenciales. Nuestros resultados indican que el tratamiento de nitrificación/denitrificación es sumamente eficiente para reducir los patógenos en los purines de cerdo y que la fase de eliminación del fósforo por medio de la precipitación alcalina con calcio produce un efluente higienizado que puede resultar importante por razones de bioseguridad