Radiation effects on residents caused by comprehensive utilization of slag in building materials / 中国辐射卫生

Objective This study intends to analyze the radioactivity level of slag and its building materials, estimate the effective dose of the residents caused by the comprehensive utilization of slag in building materials, and provide basis for rational utilization of slag. Methods Data of slag production and its comprehensive utilization in building materials, radioactive level investigation and detection of slag and building materials in different periods and regions were collected from 2005 to 2016. Using the room model of concrete structure and the model of calculating equilibrium equivalent radon concentration with the specific activity of 226Ra in indoor building materials, the external and internal radiation doses of residents caused by comprehensive utilization of slag for building materials were estimated respectively, and then the annual additional effective dose and collective dose of residents were estimated. Results The contents of 226Ra and 232Th in the slag were relatively high, while the contents of 40K were relatively low. The radionuclide content in slag cement decreased significantly. The annual additional effective doses of slag used in concrete and cement mixture relative to ordinary cement were 0.40 mSv·a−1 and 0.20 mSv·a−1 respectively. The annual additional collective dose and 50-year collective dose caused by slag used in building materials were 3.87 × 103～1.84 × 104 man·Sv and 1.94 × 105～9.20 × 105 man·Sv respectively. Conclusion The comprehensive utilization of slag in building materials increases the additional effective dose of residents, so the use of some slag in building materials needs to be paid more attention to. In addition, the influence of comprehensive utilization of slag in building materials, such as the way, the amount of slag and the amount of building materials, on the annual additional effective dose of residents caused should also be paid attention to.

Advances in microbial remediation of the re-dissolved chromium contaminated sites / 生物工程学报

Wet detoxification has traditionally been seen as the most promising technology for treating chromium-contaminated sites. However, the addition of chemicals in the wet detoxification process not only increases the cost but also introduces extra pollutants. Moreover, the chromium-containing slag may be re-dissolved in the form of Cr(VI), and the increased concentration of Cr(VI) results in a serious "returning to yellow" phenomenon in the chromium-contaminated sites, causing undesirable secondary pollution. Microbial remediation is a promising technology to address the re-dissolution of chromium-containing slag after wet detoxification, and this article reviews the advances in this area. Firstly, the toxicity, current situation and conventional technologies for treating the chromium-containing slag were briefly summarized. The mechanisms of the inevitable re-dissolution of chromium-containing slag after wet detoxification were summarized. Three main mechanisms, namely bioreduction, biosorption and biomineralization, which are involved in the environmental-friendly and efficient microbial remediation technology, were reviewed. The variation of microbial species and the succession of microbial community during the bioremediation of chromium-contaminated sites were discussed. Finally, future research directions were prospected with the aim to develop long-term, stable and sustainable technologies for remediating the chromium-contaminated sites.

EFFECT OF DIFFERENT SUBSTRATES AND AUXINS ON ROOTING OF Leucadendron sp. (PROTEACEAE) / EFECTO DE DIFERENTES SUSTRATOS Y AUXINAS EN EL ENRAIZAMIENTO DE Leucadendron sp. (PROTEACEAE)

ABSTRACT Colombian flower growers are faced with economic and social problems, so they are looking for alternatives, which include Proteas, ornamentals that require research that ensures an appropriate, local technical management. One of the Proteas most likely to be involved in this search is the genus Leucadendron. Therefore, this study aimed to establish the best basis for rooting its cuttings. The experimental design was a split plot design with a factorial arrangement. Four substrates were evaluated in combination with two auxins, naphthaleneacetic acid (NAA) and indolebutiric acid (IBA), three doses each, plus a commercial control. Each treatment was repeated three times and the experimental unit consisted of 30 stakes at the first locality and 25 at the second one. The most relevant results showed that vermiculite was the best substrate for rooting cuttings of Leucadendron at both localities. Also, it was identified that IBA is the growth regulator which improved the rooting percentage, the root volume, the stem decreased the percentage of losses.

RESUMEN Los cultivadores colombianos de flores tradicionales están confrontados con problemas, tanto económicos como sociales, por lo que están buscando alternativas, que incluyen a las Proteas, ornamentales que requieren investigación, que asegura un manejo técnico. Una de las Proteas con más posibilidad de estar involucrado en este desarrollo es el género Leucadendron. El diseño experimental empleado fue un diseño de parcelas, divididas con arreglo factorial. Así, que el objetivo de este estudio fue establecer la base para el enraizamiento de las estacas. En combinación con dos auxinas, ácido 1-naftalenacético (ANA) y ácido indolbutírico (AIB), tres dosis de cada una y el control comercial, se evaluaron cuatro sustratos. Cada tratamiento, se repitió tres veces y cada unidad experimental consistió en 30 estacas, para la primera localidad y de 25, para la segunda. Los resultados más relevantes mostraron que el mejor sustrato para el enraizamiento de estacas de Leucadendron fue la vermiculita, en ambas localidades. También, se identificó que AIB es el regulador de crecimiento que mejoró el porcentaje de enraizamiento, el volumen de raíces, la longitud del tallo disminuyó el porcentaje de pérdidas.

Characterization of two metal resistant Bacillus strains isolated from slag disposal site at Burnpur, India.

Two strains of Bacillus sp. resistant to arsenate and lead designated as AsSP9 and PbSP6, respectively were isolated from the slag disposal site. They were identified to be related to Bacillus cereus cluster on the basis of 16S rDNA based sequence analysis and phenotypic characteristics. Both were rod-shaped (AsSP9, 2-5 μm and PbSP6, 2-4 μm), aerobic, salt tolerant (2-8% NaCl), endospore forming bacteria with minor differences like the AsSP9 showed sporangial bulging and PbSP6 had positive lipase activity. The temperature range for their growth was 20-40oC and pH range 6.0-9.0 with an optimum temperature of 37oC and pH of 7 for both strains. The principal nitrogen sources for AsSP9 and PbSP6 were DL-Tryptophan and L-Phenylalanine, respectively. The suitable carbon source for AsSP9 was lactose and for PbSP6 sucrose. The heavy metal accumulation efficiency was found to be 0.0047 mg g-1 of dry mass for AsSP9 and 0.686 mg g-1 of dry mass for PbSP6.

Calcário e silicato aplicados em eucalipto: efeito no solo e na planta / Lime and silicate applied in eucalypt: effect on soil and plant

A escória siderúrgica, constituída de silicato de cálcio é uma alternativa para a correção da necessidade de Ca e Mg dos solos. O presente trabalho foi desenvolvido na Fazenda Floresta do Lobo - Uberlândia-MG para avaliar os efeitos da aplicação de escória como fonte de Si, Ca e Mg no crescimento do eucalipto em comparação à calagem. O experimento foi instalado em LATOSSOLO VERMELHO distrófico típico, em 30/11/2005, em DIC, em esquema fatorial 5x2 para a comparação de duas fontes de corretivos de acidez, com cinco doses e cinco repetições. Os tratamentos referentes às doses de escória e calcário foram aplicados nas proporções 0,1 /4, 1 /2 1 (1,5 t ha-1) e 2 vezes a necessidade corretivo. A escória proporcionou maior fornecimento de Si quando comparada com o calcário, apresentando comportamento linear. Quanto ao teor de Mg, esse foi fornecido em maior quantidade pelo calcário dolomítico. Analisando o teor de Ca e o DAP observa-se que não houve diferença significativa entres as fontes, sendo que ambos apresentaram comportamento linear. Os corretivos aumentaram o teor de Ca, Mg e DAP.

Slags, consisting of calcium silicate, are an alternative for the correction of Ca and Mg requirements in soils. This study was done at Fazenda Floresta do Lobo - Uberlândia-MG, to evaluate the effect of slag application as a source of Si, Ca and Mg for the growth of eucalypt in comparison to lime. The experiment was done in a typical dystrophic red latosol, on November 30 2005, in a completely randomized design, as a 5x2 factorial to compare two sources of soil correctives in five doses, with five replications. The treatments of slag and lime were applied in the proportion of 0, », ½, 1 (1.5 t ha-1) and 2 time the corrective requirement. Slag supplied more Si than lime, showing a linear response. In contrast, magnesium was supplied in greater amounts by dolomitic lime. No differences were found for Ca contents and the DBH (diameter at breast height) between the two sources, and both of them had linear responses. It can be concluded that the correctives increased the contents of Ca, Mg and the DBH.

Influence of accumulation of heaps of steel slag on the environment: determination of heavy metals content in the soils

The presence of high level of heavy metals involves a human healthy risk that could induce chronic diseases. This work reports on the metal contamination due to heaps of steel-slag accumulated during more than 40 years in allotments and industrial areas in the southern part of Madrid (Spain). Several slag and soil samples were collected in an area of 10 km² and characterized by different conventional (XRD and XRF) and no so common methods (ESEM, thermoluminescence and EDS-WDS). The analysis reveal the presence of: (i) important amounts of Fe (43 percent), Mg (26 percent), Cr (1.1 percent), Mn (4.6 percent), S (6.5 percent) in the form of Fe-rich slag phases (wustite, magnetite...), Si and Ca-rich phases (larnite, ghelenite...), Cr (chromite), Mn (bustamite) and graphite, (ii) traces of some other contaminants such as Cr (7700 ppm), Zn (3500 ppm), Ba (3000 ppm), Pb (700 ppm) or Cu (500 ppm) on pathway soil samples that come from the steel slag, and (iii) Co (13 ppm), Pb (78 ppm) and V (54 ppm) in farmland soil samples. Although the existing heavy metals content is not appropriate for the current use, the extremely high metal contamination of the surrounding areas is more worrying. The properties of the soil farmlands (pH circa 7, 13 percent of clay, mainly illite, and 1-4 percent of organic matter content) show suitable conditions for the retention of cationic metals, but further studies on the movilization of these elements have to be performed to determine the possibility of severe human health risks. This sort of study can provide useful information for the politicians regarding the appropriate use of the territory to prevent possible health hazard for the population.

A presença de altos niveis de metais pesados envolve riscos à saúde humana e pode induzir doenças crônicas. Este trabalho relata a contaminação metálica causada por pilhas de escória siderúrgica acumulada durante mais de 40 anos em áreas industriais na parte sul de Madrid (Espanha). Amostras de escória e solo foram coletadas em uma área de 10 km² e caracteri-zada por diferentes métodos, convencionais (XRD, XRF) ou não (ESEM, termoluminescência e EDS-WDS). A análise revela a presença de: i) quantidades importantes de Fe (43 por cento), Mg (26 por cento), Cr (1,1 por cento), Mn (4,6 por cento), S (6,5 por cento) formando várias fases ricas em Fe (wüstita, magnetita), Si e Ca (larnita, guelenita), Cr (cromita), Mn (bustamita) e grafite; (ii) tiajos de outros contaminantes, como Cr (7700 ppm), Zn (3500 ppm), Ba (3000 ppm), Pb (700 ppm) e Cu (500 ppm), no solo dos caminhos para as pilhas de resíduos e (iii) Co (13 ppm), Pb (78 ppm) e V (54 ppm) em amostras de solo agrícola. Embora os teores de metais pesados não sejam apropriados para uso corrente, a elevada contaminação de areas adjacentes é mais preocupante. Os solos adjacentes (pH ca. 7, 13 por cento de argila - principalmente ilita) e 1-4 por cento de matéria orgânica mostram condições adequadas para a retenção de cátions, mas outros estudos deverão ser realizados para determinar a possibilidade de riscos à saúde humana. Este tipo de trabalho pode fornecer informaçãoo útil para gestores públicos, com relação ao uso do território e prevenção de riscos à saúde da população.

Reatividade de escórias silicatadas da indústria siderúrgica / Reactivity of silicate slags of the iron and steel industry

As escórias siderúrgicas são usadas na agricultura, mas são poucos os trabalhos sobre sua reatividade. Neste trabalho, objetivou-se avaliar escórias siderúrgicas em diferentes frações granulométricas quanto à correção do pH e liberação de Ca, Mg e Si para o solo. O delineamento foi inteiramente casualizado com 4 repetições em esquema fatorial com 6 fontes (escória de alto-forno 1, escória de fosfato, escória de alto-forno 2, escória de aciaria de forno AOD, escória de aço inox e escória de forno LD) e 5 distribuições granulométricas (2 - 1,41; 1,41 - 0,85; 0,85 - 0,50; 0,50 - 0,30 mm e < 0,30 mm) e dois tratamentos adicionais (testemunha e CaCO3). O CaCO3 foi usado como padrão para a determinação do índice de reatividade de cada escória. Foram aplicados 1500 mg kg-1 de equivalente CaCO3 e em todos os tratamentos e as doses de cada escória foram calculadas pelo seu PN-determinado. Houve aumento do pH com a redução do tamanho das partículas para todas as escórias. A escória de fosfato apresentou maior eficiência na liberação de Ca + Mg em relação ao carbonato quando o tamanho das partículas foi menor que 0,5 mm. Houve baixa eficiência na correção da acidez e liberação de Ca e Mg no solo nas.escórias de alto forno. Para maior liberação de silício, é necessário utilizar partículas de tamanho menor (<0,3 mm) para a escória de fosfato e de aço inox tamanhos intermediários (0,85 a 1,41), enquanto para a escória AOD e LD não há interferência da granulometria.

The slags are used in the agriculture as soil acidity correctives in same rates of lime, but there are few studies about its reactivity in soils. The objective was to compare slag reactivity to soil acidity correction and calcium, magnesium, and silicon liberation. A completely randomized experimental design was used, with 4 repetitions in factorial with 6 sources (blast furnace slag 1, phosphate slag, blast furnace slag 2, AOD furnace steel slag, stainless steel slag and LD furnace steel slag) and 5 particle sizes (2-1.41; 1.41-0.85; 0.85-0.50; 0.50-0.30 mm and < 0,30 mm) and two additional treatments (control and CaCO3). The CaCO3 was used as a pattern for the determination of the reactivity index of each source. All treatments received 1500 mg kg-1 of equivalent CaCO3 and each rate of slags was calculated by its determined neutralization power. The pH-value increased with reduction of particle size in all slags. The phosphate slag showed best efficiency on the liberation of Ca + Mg compared to the calcium carbonate in the granulometrics inferior to 0.5 mm. There was low efficiency in soil acidity correction and liberation of the Ca and Mg in soil to slag of blast furnace. It is necessary to use particles smaller than 0.3 mm to improve silicon availability of phosphate slag and particles between 0.85 and 1.41mm to stainless steel slag. The silicon availability of AOD furnace steel slag and LD furnace steel slag were not influenced by particle size.

Níveis de silicato de cálcio e magnésio na produção das gramídeas Marandu e Tanzânia cultivadas em um Neossolo Quartzarênico / Level of calcium and magnesium silicate in the yield of Marandu grass and Tanzania grass cultivated in one Quartzsandy Neosoil

O estudo foi conduzido em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras, Lavras-MG, com o objetivo de avaliar o efeito da correção da acidez do solo, por meio da aplicação de níveis de silicato de Ca e Mg, na produção das gramíneas Brachiaria brizantha cv. Marandu e Panicum maximum cv. Tanzânia-1 cultivadas em solo Neossolo Quartzarênico ortic. O delineamento experimental utilizado foi blocos ao acaso, em esquema fatorial 2 x 5 com quatro repetições, sendo duas forrageiras e cinco níveis de saturação por bases (V por cento original, 40, 60, 80 e 100 por cento). Cada unidade experimental correspondeu a um vaso sem furos, com capacidade para 4,0 dm³ de solo, totalizando 40 vasos. Foram avaliadas as produções de MS por corte (PMS) e total (PTMS), a altura e o número de perfilhos. Não houve variação entre as gramíneas em altura de perfilhos. O Tanzânia foi superior ao Marandu em PMS e número de perfilhos. Houve aumento linear na PMS, PTMS e altura de perfilhos. Conclui-se que ambas as gramíneas responderam de forma positiva à elevação dos níveis de V por cento, em PMS, até 54,8 por cento. O Tanzânia produziu mais MS em relação ao Marandu.

This study was conducted in a greenhouse of the Soil Science Department at Universidade Federal de Lavras, Lavras-MG, with the purpose of evaluating the effect of the soil correction acidity, by the application of Ca and Mg silicate levels, in the production of grasses Brachiaria brizantha cv. Marandu and Panicum maximum cv. Tanzânia-1 cultivated in Quartzsandy Neosoil ortic. The experimental design was a randomized complete block, in 2 x 5 factorial scheme with four replicates, being two forages and five levels of base saturation (BS percent); (original BS, 40, 60, 80 and 100 percent). Each experimental unit corresponded to a pot with a capacity of 4.0 dm³ of soil, totalizing 40 pots. The dry matter yield (DMY) for cut and total (TDMY), height and number of tillers were evaluated. There were no variations among the grasses in tiller height. Tanzania grass was superior to Marandu grass in DMY and tiller number. There were linear increases in DMY, TDMY and tiller height as the BS percent levels increased. It follows that both grasses responded positively to the rise of BS percent in DMY until 54.8 percent. Tanzania grass produced more DM in relation to Marandu grass.

Cloning,expression and characterization of sLAG-3-Ig / 中国病理生理杂志

AIM: To obtain a vaccine with sLAG-3 as immunoadjuvant and investigate its biologic activity in order to establish the safe and effective way for asthma as one of the specific immunotherapy.METHODS: The coding sequence of LAG-3 was amplified by polymerase chain reaction,the expression vector pcDNA-sLAG-3-Ig was constructed by inserting the PCR products of sLAG-3 and Fc sequence of IgG.With electroporation transfection,pcDNA-sLAG-3-Ig was transfected into COS-7 cells and its biologic activity was investigated by Western blotting analysis.RESULTS: By temperature induction,the LAG-3-Ig was highly expressed in E.coli DH5?.LAG-3-Ig fusion protein was observed by SDS-PAGE and Western blotting,the results showed that the LAG-3-Ig protein was an antagonist of the IL-4-induced synthesis of IgE in B cells.CONCLUSION: A new vaccine with sLAG-3 as immunoadjuvant was obtained.It could inhibit synthesis of IgE in B cells.Thus,LAG-3-Ig would be hopeful to establish the safe and effective way for asthma as one of the specific immunotherapy.