RESUMO
This work aimed to measure the odour impact of untreated cow and pig slurries and treated (digestate and liquid fraction of digestate) manures when they were used on soil at a field scale, while also testing different spreading methods, i.e. surface vs. injection. Five experiments were performed in 2012-2016 on different farms. Odours were quantitatively (specific odour emission rate - SOER) (OUEm-2h-1) measured by using dynamic olfactometry and qualitatively, i.e. to obtain an "odour fingerprint", by using an electronic nose (EN). Anaerobic digestion was effective in allowing the reduction of potential odour emission from digestates, so that when they were dosed on soil, odours emitted were much lower than those from soils on which untreated slurries were used. Slurries/digestate injection reduced much more odour emitted by soils so that SOER tended to become more similar to that of the control (untreated soil) although the odours were slightly greater. Odour fingerprint data indicated that there was a direct correlation between SOER and odour fingerprints. This was due to the ability of EN to detect ammonia, S-compounds and methane that were (the first two mainly), also, responsible for odours. Very good regression was found for Log SOER and EN by using a Partial Least Square (PLS) approach (R2=0.73; R2cv=0.66; P<0.01) for matrices used to fertilize soils in lab tests. Unfortunately, regression was not so good when odour data from field experiments on soil were used, so that EN cannot be proposed to replace olfactometry. EN fingerprints for control (Blank) and injected organic matrices were virtually identical, due to the creation of cavities in the soil during the injection that decreased the treated surface. Anaerobic digestion and subsequent digestate injection allowed us to reduce odour impact, avoiding annoyance to local inhabitants.
RESUMO
This work represents the first attempt to evaluate the precision of the specific oxygen uptake rate method expressed in terms of repeatability (r) and reproducibility limits (R). Three laboratories were involved in an inter-laboratory test for the validation of respiration analyses on six biomass samples (three composts and three biostabilized products) having different degrees of biological stability. Both the maximum specific oxygen uptake rate peak (SOUR) and the cumulative oxygen demand after 12 h (OD(12)) and 20 h (OD(20)) of respiration test were investigated. Precisions expressed as the relative standard deviation were in the range of 9-41%. Linear regressions found for r and R, versus OD(12) and OD(20), enabled derivation of precision values (r and R) for all respirometric levels within the operating range. The OD(12) and OD(20) indices were found to be more adequate to indicate biological stability since they were less influenced by random errors than the SOUR index.
Assuntos
Oxigênio/metabolismo , Solo , Reprodutibilidade dos Testes , Temperatura , Fatores de TempoRESUMO
In this paper, the effect of biodrying process on municipal solid waste (MSW) properties was studied. The results obtained indicated that after 14d, biodrying reduced the water content of waste, allowing the production of biodried waste with a net heating value (NHV) of 16,779±2,074kJ kg(-1) wet weight, i.e. 41% higher than that of untreated waste. The low moisture content of the biodried material reduced, also, the potential impacts of the waste, i.e. potential self-ignition and potential odors production. Low waste impacts suggest to landfill the biodried material obtaining energy via biogas production by waste re-moistening, i.e. bioreactor. Nevertheless, results of this work indicate that biodrying process because of the partial degradation of the organic fraction contained in the waste (losses of 290g kg(-1) VS), reduced of about 28% the total producible biogas.
Assuntos
Eliminação de Resíduos/métodos , Dessecação/métodos , Temperatura Alta , OdorantesRESUMO
Odours (OU(E)) and volatile organic compounds (VOC) emission during biological process used to treat MSW were studied under standardized conditions in order to detect potential risk for workers and population. Results obtained indicated that odours and VOCs emitted depend on the biological stability of waste measured by the dynamic respiration index (DRI) and a very good correlation were found between these parameters (OU(E) vs. DRI, r=0.96, p<0.001, n=6; VOC vs. DRI, r=0.97, p<0.001, n=6). GC-MS study of the VOCs indicated the presence of a group of molecules that were degraded during the process. On the other hand, a second group of molecules, i.e. aromatic and halogenated compounds, and furan persisted in the waste sample, although molecule concentrations were always lower than Threshold Limit Value-Time Weighted Average (TLV-TWA).
Assuntos
Odorantes , Eliminação de Resíduos , Respiração , Compostos Orgânicos Voláteis/metabolismo , Biodegradação Ambiental , Furanos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidrocarbonetos Aromáticos/metabolismo , Hidrocarbonetos Halogenados/metabolismoRESUMO
Ten cases of malignant lymphoma of the female urethra have been reported. To our knowledge we report the first such case in a man who presented in acute urinary retention with a mass protruding from the urethral meatus. Multiple subcutaneous nodules developed over the anterior abdominal wall and a 3 x 3 cm. mass developed above the umbilicus. Wedge resection of this mass was consistent with large cell lymphoma. Treatment consisted of 2 courses of arabinoside C, doxorubicin and prednisone. Followup 6 months later showed no urethral or other recurrence. Local excision, radical excision, radiotherapy (external beam and intracavitary) and chemotherapy have been used with success in other cases.