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1.
J Environ Manage ; 231: 232-240, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30342336

RESUMO

The development of technologies for unconventional hydrocarbon exploration requires designing procedures to manage drilling waste that are consistent with the waste management hierarchy. In view of this, the possibility to apply shale drill cuttings as a prospective additive (replacing bentonite) to fly ash used for the production of lightweight aggregates (LWAs) was investigated. Moreover, a facile, waste-free method of LWAs production with using shales was proposed. Cuttings were characterized in terms of their mineralogical and elemental composition (XRD and XRF) as well as thermophysical behavior (TG-DTA and fusibility test). The sintered product, in turn, was assessed taking into account its structure, physicochemical and mechanical properties. It was found that the composition of the shale drill cuttings meets the conditions required for the bloating (as expressed by the SiO2/ΣFlux and Al2O3/SiO2 ratios) and binding processes (Al2O3 content), essential for the aggregates production. In comparison to bentonite, shales provided an additional source of kaolinite, which thermal transformation to mullite is crucial for the formation of mechanically durable structure of the aggregate. Moreover, the bulk density of the sintered product was found to be less than 1200 kg/m3, and the dry particle density below 2000 kg/m3, confirming that the obtained porous material belong to lightweight aggregates with accordance to European standard (UNE-EN-13055-1). The porosity of LWA was found to be higher (even up to 50%), thus the apparent density lower, compared with the reference product containing bentonite. These properties were accompanied by the relatively high crushing resistance which was up to 4.4 N/mm2. Hereby, usefulness of shale drill cuttings for LWAs production was confirmed.


Assuntos
Dióxido de Silício , Gerenciamento de Resíduos , Bentonita , Cinza de Carvão , Estudos Prospectivos
2.
Water Sci Technol ; 49(4): 261-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15077981

RESUMO

Photodegradation of organic pesticides in industrial wastewater was examined in a UV/H2O2/air system. An experimentally determined optimal amount of hydrogen peroxide (0.008% v/v) indicates that hydrogen peroxide concentration controlled the efficiency of photodegradation. Pre-treatment operations such as sedimentation, filtration and coagulation were used to obtain better efficiency of pesticide removal and to cut down on irradiation time. Finally, scale-up experiments in the air-sparged hydrocyclone (ASH) reactor were carried out. After 5 min irradiation of 100 dm3 industrial wastewater almost all pesticides were destroyed. Thus the ASH reactor proved to be an effective contactor for carrying out photochemical reactions.


Assuntos
Peróxido de Hidrogênio/química , Oxidantes/química , Praguicidas/química , Praguicidas/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Gases , Resíduos Industriais , Fotoquímica , Raios Ultravioleta
3.
Cent Eur J Public Health ; 8 Suppl: 88-9, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10943487

RESUMO

In the last decade advanced oxidation processes (AOPs) have been gaining importance for destruction of waste as cleaner methods enabling conversion of organic contaminants to harmless species. Photodegradation processes in the presence of hydrogen peroxide (H2O2), ozone (O3) and titanium dioxide (TiO2) are most frequently offered for wastewater treatment. The novel gas-sparged reactor equipped with UV lamp proved to be an efficient system for photochemical degradation. In this investigation 80 ppm aqueous solution of phenol was treated for 40 minutes. 13% of phenol was eliminated in the UV/air system and 73% in the UV/H2 O2/air system at 80 l/min air flowrate. Air sparging did not result in phenol removal with the gas phase.


Assuntos
Ar , Peróxido de Hidrogênio/química , Compostos Orgânicos/química , Raios Ultravioleta , Oxirredução
4.
Cent Eur J Public Health ; 8 Suppl: 37-8, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10943452

RESUMO

Aqueous solutions containing 200 mg/dm3 of p,p'-DDT and methoxychlor were photodegraded for 60 min in UV/TiO2/O2 system and chloride ions concentration and pH were measured. From 60 to 80% of the investigated pesticides were eliminated after treatment. Over 27% of chlorine atoms were splitted off for methoxychlor and 10% for p,p'-DDT. The experimental data suggest, that chlorine atoms were removed from the -CCl3 moiety but the chlorine atoms bound to aromatic ring were left intact at this step of photodegradation.


Assuntos
Cloretos/química , DDT/química , Inseticidas/química , Metoxicloro/química , Titânio/química , Cinética , Microesferas
10.
Bibl Cardiol ; (33): 113-6, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1131163

RESUMO

Ballistocardiography was used for following up the changes in cardiovascular dynamics in 2 groups of patients suffering from hypertensive disease stage II. In a group of hypertensive patients who took CO2 baths for 28 days, or improvement of the pathologically altered Bcg showed with a simultaneous decrease in blood pressure and pulse rate for a better dynamics of the cardiac function. In the group of hypertensive patients taking isothermic tap-water baths under identical conditions, the same trend in the Bcg changes was found, but these changes were not statistically significant.


Assuntos
Balistocardiografia , Banhos , Dióxido de Carbono , Coração/fisiopatologia , Hipertensão/terapia , Pressão Sanguínea , Eletrocardiografia , Coração/efeitos dos fármacos , Humanos , Hipertensão/fisiopatologia , Pessoa de Meia-Idade , Pulso Arterial , Respiração
11.
Bibl Cardiol ; (33): 17-20, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1131178

RESUMO

A comparison of Bcg changes was made between a group of healthy individuals, a group of pneumopaths with normal blood pressure in the pulmonary artery at rest and another group of pneumopaths with pulmonary hypertension at rest. The tension in the pulmonary artery was measured by venous catheterization. It was found that: (1) the H wave of the Bcg was significantly higher in both groups of pneumopaths than in the group of healthy individuals, and (2) the L wave was significantly higher in pneumopathics with pulmonary hypertension at rest than in pneumopaths with pulmonary normotension and healthy individuals.


Assuntos
Balistocardiografia , Coração/fisiopatologia , Hipertensão Pulmonar/fisiopatologia , Adulto , Pressão Sanguínea , Eletrocardiografia , Humanos , Pessoa de Meia-Idade , Respiração
12.
Aktuelle Gerontol ; 11(4): 114-8, 1981 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-6116449

RESUMO

Oral and intravenous glucose tolerance tests were performed in three different age groups, separately for men and women. Blood glucose and insulin levels were examined. Advanced age is associated with reduced glucose tolerance independent whether it is investigated by means of intravenous or oral glucose application. Concomitant examination of plasma insulin, however, differentiates between the intravenous and the oral glucose tolerance test. While the high insulin levels after oral glucose administration are rather increasing with age, the minor insulin reaction after the intravenous glucose route is decreasing with advancing age. Results of the intravenous and the oral glucose tolerance test reveal no difference between male and female subject as long as blood sugar is examined. However, insulin levels and the insulinogenic index are consistently higher in men than in women.


Assuntos
Envelhecimento , Teste de Tolerância a Glucose , Insulina/sangue , Adulto , Idoso , Glicemia/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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