257 resultados para laboratory waste

em Scielo Saúde Pública - SP


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The Laboratory Waste Management Program of the Chemistry Department of UFPR started on 1997 and was developed to meet the requirements of co-processing in cement kiln and those of the respective regulation. The in-lab procedures for waste collection and treatment were devised taking into account their cost, simplicity and wide range of application to the various types of residues generated. The program works with a five step annual journey : 1) Waste collection and treatment, 2) Bulk Storage, 3) Licensing (for transportation and co-processing), 4) Transportation and 5) Co-processing.

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This work shows some laboratory waste management developed in order to recover some elements or to prepare the waste for a correct final disposal. The 25 elements chosen cover basically all chemical behaviors found for the metals in the Periodic Table. The treatments adopted were based on the classical behavior in aqueous solution (wet chemistry) but an important condition for a full success was the previous knowledge of the qualitative composition of the wastes treated. Some general trends were found: the final liquid waste was always saline and normally presented a higher volume than the original waste; most original wastes were acid in nature; steps such as solid-liquid separation, washing, evaporating and calcining were currently performed. This work was also a very good experience in chemistry in solution for students and showed them the need of treating wastes for a better environment.

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A laboratory procedure was devised to recover bromine from waste alkaline aqueous solutions used in the isotopic determination of N-15. The laboratory apparatus comprises two round bottom flasks (1 and 2 L), a dropping funnel, a gas bubbler, a gas regulator and glass fittings. The waste solution is acidified with sulfuric acid forming molecular bromine that is stripped out by a flow of nitrogen gas bubbled through the solution. This gas is then bubbled through a solution of lithium hydroxide generating lithium bromide and lithium hypobromite. The efficiency of bromine recovery was estimated to be 82±2%. This resulting solution was successfully reused in the isotopic determination of N-15. The procedure can recycle most of the bromine used in the laboratory saving resources and preserving the environment. The procedure can be adapted to recover bromine of other laboratory waste streams.

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This work presents the students´ profile before and after working in the course "Laboratory Chemical Waste Treatment" in the last ten years. The structure of the course is also described. Although students have shown an increasing previous experience on waste management, many fundamental aspects are missing, especially knowledge on the directives focusing environmental aspects. Visits to industrial plants are also essential to better understand the impact of wastes in environment. Most students nowadays consider waste management as an essential part of their professional formation. A good waste management program must consider several topics of extreme relevance.

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This work shows routes to recover some elements from their laboratory wastes and broken apparatus (thermometers and densimeters). Most elements chosen present a chemical behavior in aqueous solution which is not currently studied in the ordinary experimental classes. The routes were based on the previous knowledge of the qualitative composition of the wastes treated. Wastes containing chromium were the most difficult to treat. The elements were recovered in good yields and can be reused in new experiments. This work was a very good experience in chemistry for students and shows the need of managing wastes for a better environment.

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This study aims to analyze the enteroparasitic occurrence in children from 0 to 12 years old consulted at the University of western São Paulo Clinical Laboratory, Presidente Prudente, SP, Brazil, in relation to the socioeconomic profile of the attended children. Stool samples were examined and a questionnaire was applied with the objective of knowing the patient's age, sex, medical attendance, characteristic of the habitation, provisioning of water, dejection and domestic waste fates, use of footwear and clinical signs. The software EPI INFO 6 (Version 6.04b) was used for the elaboration of the data bank structure and analysis after previous data codification. Among 1,000 children analyzed, as many as 21.3% presented some kind of parasite. The most frequent protozoan was Giardia lamblia (7.3%) followed by Entamoeba coli (3.9%). The most frequent helminth was Enterobius vermicularis (1.9%) followed by Hymenolepis nana (0.5%). The most frequent protozoan association was Giardia lamblia / Entamoeba coli (0.9%).

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Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) are widely used in academic institutions and laboratories for quality control to analyze inorganic elements in samples. However, these techniques have been observed to underperform in sample nebulization processes. Most of the samples processed through nebulization system are discarded, producing large volumes of waste. This study reports the treatment and reuse of the waste produced from ICP OES technique in a laboratory of analytical research at the Universidade Federal do Ceará, Brazil. The treatment of the waste was performed by the precipitation of elements using (NH4)2CO3. Subsequently, the supernatant solution can be discarded in accordance with CONAMA 430/2011. The precipitate produced from the treatment of residues can be reused as a potential sample in undergraduate qualitative analytical chemistry lab classes, providing students the opportunity to test a real sample.

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The objective of the present study was to evaluate the effects of industrial solid waste (whitewash mud) on geotechnical properties considering the following engineering parameters: California Bearing Ratio (CBR), Atterberg limits and Permeability test. Seven soil samples derived from Alagoinhas, Bahia - Brazil, were classified by the Transportation Research Board (TRB) system. Two were selected as having a great geotecnical potential classified as A-3 (0) and A-2-4 (0), whitewash mud contents 10%, 15%, 20% and 25% dry weight and medium compaction effort were studied in the laboratory testing program. The results indicated the soil denominated good gravel as being the most promising one, when stabilized with whitewash mud, reaching the best results with the dosage of 20 and 25% of whitewash mud.

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In this study, was studied the biogas generation from swine manure, using residual glycerine supplementation. The biogas production by digestion occurred in the anaerobic batch system under mesophilic conditions (35°C), with a hydraulic retention time of 48 days. The experiment was performed with 48 samples divided into four groups, from these, one was kept as a control (without glycerin) and the other three groups were respectively supplemented with residual glycerine in the percentage of 3%, 6% and 9% of the total volume of the samples. The volume of biogas was controlled by an automated system for reading in laboratory scale and the quality of the biogas (CH4) measured from a specific sensor. The results showed that the residual glycerine has high potential for biogas production, with increases of 124.95%, 156.98% and 197.83% in the groups 3%, 6% and 9%, respectively, relative to the sample control. However, very high organic loads can compromise the process of digestion affecting the quality of the biogas generated in relation to methane.

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OBJECTIVE: To determine the severity of dapsone (DDS) acute intoxication – an uncommon medical event – using clinical and laboratory parameters. METHODS: Two hundred and seventy four patients with acute DDS intoxication, aged 1 month to 50 years old, were studied and classified into four age groups. Clinical evaluation was assessed through a protocol and correlated with laboratory parameters. Spectrophotometric methods were used to analyze methemoglobinemia (MHbp) and dapsonemia (DDSp). RESULTS: The most prevalent clinical sign of intoxication was cyanosis, seen in 65.7% of the patients and in 100% of children less than 5 years of age. According to laboratory criteria, MHbp-related severe clinical intoxication was seen in 56.2% and DDSp-related occurred in 58% of the patients. Regarding DDSp, intoxication was considered severe when 20 tablets (100 mg each) were ingested, a median of 29 mug/ml. Regarding MHbp, intoxication was severe when 7.5 tablets were ingested, a median of 38% of the total Hb. The correlation between MHbp and DDSp was statistically significant (n=144, r=0.32, p<0.05). Negative correlation was observed between MHbp and the time elapsed since DDS intake (n=124, r=-0.34, p<0.001). There was also a negative correlation between DDSp and the time elapsed since DDS intake (n=63, r=-0.35, p<0.0001). CONCLUSIONS: Longitudinal analysis showed a significant association between methemoglobinemia and the time elapsed after the intake (t), according to the equation: Dapsonemia = 12.9256 - 0.0682t + 0.234 methemoglobinemia

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OBJECTIVE: The clinical differential diagnosis of rash due to viral infections is often difficult, and misdiagnosis is not rare, especially after the introduction of measles and rubella vaccination. A study to determine the etiological diagnosis of exanthema was carried out in a group of children after measles vaccination. METHODS: Sera collected from children with rash who received measles vaccine were reported in 1999. They were analyzed for IgM antibodies against measles virus, rubella virus, human parvovirus B19 (HPV B19) using ELISA commercial techniques, and human herpes virus 6 (HHV 6) using immunofluorescence commercial technique. Viremia for each of those viruses was tested using a polimerase chain reaction (PCR). RESULTS: A total of 17 cases of children with exanthema after measles immunization were reported in 1999. The children, aged 9 to 12 months (median 10 months), had a blood sample taken for laboratory analysis. The time between vaccination and the first rash signs varied from 1 to 60 days. The serological results of those 17 children suspected of measles or rubella infection showed the following etiological diagnosis: 17.6% (3 in 17) HPV B19 infection; 76.5% (13 in 17) HHV 6 infection; 5.9% (1 in 17) rash due to measles vaccine. CONCLUSIONS: The study data indicate that infection due to HPV B19 or HHV 6 can be misdiagnosed as exanthema due to measles vaccination. Therefore, it is important to better characterize the etiology of rash in order to avoid attributing it incorrectly to measles vaccine.

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OBJECTIVE: To estimate the seroprevalence of HIV, hepatitis B and C and syphilis and to describe risk behaviors associated to their transmission among recyclable waste collectors. METHODS: A seroepidemiological survey was carried out in the city of Santos, Southeastern Brazil, in 2005. A total of 315 individuals were enrolled in the survey, of which 253 subjects underwent serological testing HIV, hepatitis B and C and syphilis. Statistical analysis consisted of univariate and bivariate analyses (cross-tabulation and odds ratio) and multivariate analysis (by logistic regression), relating HIV infection with established risk behaviors and seropositivity. RESULTS: Overall seroprevalences were: HIV, 8.9%; hepatitis B, 34.4%; hepatitis C, 12.4%; and syphilis, 18.4%. Subjects were characterized by a predominance of males with low educational and economic levels, subjected to parenteral and sexual exposures to HIV and other sexually transmitted infections. Multivariate analysis results indicated that risk factors for both sexually and parenterally related exposure were significantly associated with HIV in this community. CONCLUSIONS: Seroprevalences found in the study were approximately 10 to 12 times higher than the national average. These communities are socially marginalized and generally not recognized by national programs as potentially endangered populations.

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Two monoclonal antibodies anti-component 5 of Trypanosoma cruzi (I-35/115 and II-190/30) were tested in IFA and ELISA respectively against 35 T. cruzi laboratory clones. Among the 35 clones tested, 18 different isozyme patterns were detected. All clones were recognized by both monoclonal antibodies except one clone which did not react with II-190/30. These results support the universal expression of specific component 5 within the taxon T. cruzi.

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A laboratory study was conducted to test the toxicity of synthetic insecticides added to defibrinated sheep blood kept at room temperature and offered as food to the following triatomine species: Triatoma infestans, Panstrongylus megistus, Triatoma vitticeps, Triatoma pseudomaculata, Triatoma brasiliensis and Rhodnius prolixus. The insecticides used, at a concentration of 1g/l, were: HCH, DDT, Malathion and Trichlorfon, and the lethalithy observed at the end of a 7-day period varied according to the active principle of each. HCH was the most effective by the oral route, killing 100% of the insects, except P. megistus (95.7%) and T. pseudomaculata (94.1%). Trichlorfon killed the insects at rates ranging from 71.8% (T. vitticeps) to 98% (R. prolixus). Malathion was slightly less efficient, killing the insects at rates from 56.8% (T. vitticeps) to 97% (T.brasiliensis). DDT was the least effective, with a killing rate of 10% (T. vitticeps) to 75% (T.brasiliensis). Since the tests were performed at room temperature, we suggest that baits of this type should be tried for the control of triatomines in the field.