RESUMEN
As a model for aerosol transmission, chicken feces was spiked with avian influenza virus (AIV) subtype H10N7 and used to generate a fine particulate matter aerosol. For this an innovative aerosol chamber was developed, that collected PM(2.5) on quartz microfiber filters. With AIV contaminated PM(2.5) dust-coated filters different incubation times ranging from 0 to 4 days and storage mainly at +4 and +20 degrees C and at different relative humidity (RH) were performed. Embryonic death in inoculated hen's eggs with filter elute was the AIV infectivity read out. To determine viral genome presence quantitative real time RT-PCR was applied. The filter elutes contained AIV genome as well as viable virus whereby +20 degrees C indicated a borderline temperature for infectious virus stability. In addition, high relative humidity was critical for AIV viability in PM(2.5). The results allowed a dispersion calculation of infectious AIV in aerosols assuming a worst case scenario for an AIV outbreak in poultry farms. Thus exposure to AIV associated with PM(2.5) is possible near to infected farms and may be a serious risk for fatal influenza disease in both man and animals. Airborne transmission should be effectively preventable by dispersion of water combined with disinfection into the inside air as well as the exhaust air stream of AIV infected farms.
Asunto(s)
Heces/virología , Virus de la Influenza A/patogenicidad , Gripe Aviar/transmisión , Aerosoles , Animales , Embrión de Pollo/virología , Pollos/virología , Femenino , Pruebas de Hemaglutinación/veterinaria , Virus de la Influenza A/genética , Gripe Aviar/virología , Material Particulado , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Operational results of a co-digestion facility were assessed over a period of 18 months. The organic fraction of municipal solid waste (OFMSW) contains a considerable amount of contaminants and grit (up to 6% w/w). A BTA-Pulper efficiently treated the different waste streams and converted a high amount of volatile solids (VS) into the digester feedstock. The seasonal fluctuations of the waste composition significantly influenced the biogas production. The impact of this seasonally variant degradability of VS had to be considered by evaluating the operation results. The waste streams investigated did not show any negative impact on digester performance. The hydraulic retention time (HRT) in the digester considerably affected the VS-reduction. Despite a considerable decrease of VS-degradation a reduction of HRT from 14 to 8 days slightly improves the gas production rate (GPR). An activated sludge system efficiently reduced the pollution of the effluent. The nutrient content of the anaerobic compost was favourable and the content of pollutants was low. The facility produced surplus electrical power up to 290 MJ/t. An overall energy balance shows that the facility substitutes primary energy.
Asunto(s)
Bacterias Anaerobias/metabolismo , Residuos de Alimentos , Eliminación de Residuos/métodos , Bacterias Aerobias/metabolismo , Biodegradación Ambiental , Alemania , Metano/análisis , Estaciones del AñoRESUMEN
Already in the planning or monitoring phase, measures have to be realized for the reduction in emissions of bio-aerosols in biological waste treatment plants. For this purpose, operation-related measures (in open and partially closed plants) and technology-related measures (in closed plants with automatic ventilation) can be taken. A survey on the currently feasible measures for reduction is submitted. The realization has to be adapted to the individual site and type of plant. An enormous demand for examinations is envisaged in order to enable a qualified assessment of the emission behaviour of diverse waste air systems or process steps.
Asunto(s)
Microbiología del Aire , Contaminantes Ocupacionales del Aire/análisis , Contaminación del Aire/prevención & control , Monitoreo del Ambiente , Eliminación de Residuos , Contaminación del Aire/análisis , Humanos , Técnicas MicrobiológicasRESUMEN
The contribution deals with the following topics: --A possible utilization of the biological soil remediation techniques. --Laboratory investigations for remediation projects. --Development of pilot treatments projects. --Technical treatments, monitoring, and the enhancement of microbial activities on a full scale.