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The removal of non-ionic surfactants (NS), as well as a long-chained ethoxylates, short-chained NS and poly(ethylene glycols)(PEG), was investigated in two sewage treatment plants (STP) of the activated sludge type and one trickling filter type. The indirect tensammetric method (ITM), and the ITM combined with the Bismuth Active substances (BiAS) separation scheme (BiAS-ITT) were used for the determination of NS and their metabolites. on average, 85% reduction of total Ns was determined in the activated sludge type STP and 53% reduction in the case of the trickling filter type STP. significant concentrations of NS metabolites (short-chained NS and PEG) were determined in raw sewage, which indicate that NS biodegradation had already started in the sewer system. Both tensammetric methods prove to be a useful tool in monitoring Ns and their metabolites in STP.
In the years 1996-1998 in the sewage treatment plant in Hajdów an experiment was set up in order to determine the optimal number of plants and the method of proliferation of Sida hermaphrodita R. on sewage sludge. The cultivation of Sida was carried out on especially prepared plots with an added 50 cm thick layer of sewage sludge. Two methods of plantation establishing (propagation) were used - generative and vegetative. Three plant densities were used per 1 ha: 3 kg of seeds or 33,000 seedlings; 6 kg of seeds or 50,000 seedlings; and 9 kg of seeds or 100,000 seedlings. A higher yield of stems and greater amounts of Fe extracted from the sludge were obtained from vegetative plant propagation. In the conditions of greater number of plants, considering stem yield, Sida took from the sludge more Co, Fe, and Ni. The three-year cultivation of Sida hermaphrodita caused positive changes in the structure of the sewage sludge.
A questionnaire study was performed in 99 workers at a large sewage treatment plant to investigate self-reported health complaints from workplace exposure to bioaerosols. The study population was divided into subgroups according to different work stations: mechanical treatment (MT), biological treatment (BT), sewage sludge treatment (SST) and operation control (OC). The questionnaire included personal data, workpost and job characteristics, exposure to chemicals, history of employment and exposure, workplace hygiene and protective measures, smoking and drinking habits. There was also a series of 25 questions on subjective health complaints grouped into the following clusters: 'flu-like symptoms', 'respiratory symptoms', 'nose, eye, throat and skin irritation', 'neurological symptoms' and 'gastrointestinal symptoms'. Each subject was asked whether the complaints had occurred 'frequently', 'rarely', or 'never' within the previous 12 months. Air concentrations of endotoxins and (1›3)-ß-D-glucans in the worker's breathing zone were also determined. The measurements of concentrations were made in the summertime during a morning shift. To determine endotoxins concentration, the Chromogenic Limulus Amebocyte Lysate (LAL) Test was applied. The questionnaire data and determination results were subject to a statistical analysis. No statistically significant relationship was found between the reported health complaints and such variables as job title, exposure to endotoxins and glucans, tobacco smoking, age and period of employment as sewage worker. The findings revealed that among the complaints, muscle and joint ache was reported most frequently, while among the symptom clusters, the flu-like symptoms prevailed. These symptom clusters occurred most frequently in OC workers, and were least often found in SST workers. In the worker's breathing zone, the geometric mean concentration of endotoxins amounted to 20.3 ng/m3 and of glucans to 7.76 ng/m3, and was not related to job title or job characteristics. A high correlation was found between endotoxins and (1→3)-ß-D-glucans concentrations (Pearson correlation coefficient 0.86, p<0.0005).
Artykuł przedstawia ocenę skuteczności hydrofitowego systemu doczyszczania ścieków obciążnych zmiennym (pod względem ilościowym i jakościowym) ładunkiem ścieków browarniczych, na przykładzie oczyszczalni w Sierpcu. Rezultaty badań uzyskane w latach 2002-2004 wskazują, że oczyszczalnia hydrofitowa służąca doczyszczaniu ścieków pochodzących z komunalnych oczyszczalni ścieków obciążonych znacznym ładunkiem substancji organicznych jest stosunkowo efektywna metodą. Analiza wyników badań wykazała, że hybrydowy hydrofitowy system doczyszczania ścieków znacząco podwyższa i stabilizuje efektywność pracy oczyszczalni w Sierpcu. Skuteczność doczyszczania ścieków w systemie hydrofitowym wzrastała z każdym rokiem pracy systemu. Dokonano oceny możliwości praktycznego zastosowania tego systemu i stwierdzono, że dla efektywnego oczyszczania ścieków w Sierpcu, minimalna powierzchnia oczyszczalni hydrofitowej powinna wynosić 2 ha.
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