礦物加工外文翻譯---鈾礦山酸性水中硫酸鹽還原菌的檢測（原文）

1、Technical noteMonitoring of sulfate-reducing bacteria in acid water from uranium minesJ.S. Benedetto *, S.K. de Almeida, H.A. Gomes, R.F. Vazoller, A.C.Q. LadeiraCentro de Desenvolvimento da Tecnologia Nuclear—CDTN/CNEN,

2、 R. Prof. Ma ´rio Werneck s/n, Campus da UFMG, Pampulha, 30123-970 BH, MG, BrazilReceived 3 May 2005; accepted 24 August 2005 Available online 17 October 2005AbstractOne of the most serious environment problems crea

3、ted by the mining industry is acid mine drainage. In one plant of Nuclear Indus- tries of Brazil—INB, this problem is a matter of concern. The presence of iron sulfites, such as pyrite, generates water with acidity above

4、 the levels allowed by the legislation and therefore, inappropriate for releasing straight into the environment. The industry maintain a high cost treatment in acid water from mines and waste disposal which consists in n

5、eutralizing and precipitating heavy metals. The treatment of acid water using sulfate-reducing bacteria (SRB) has been used in other countries with quite good technical results as well as econom- ical advantages and thus

6、, the object of this research. A seasonal study was carried out on the sulfate-reducing bacteria present in the liquid effluent discharged from two wastes disposal of the uranium mine, in phase of decommission, in Poc &#

7、184;os de Caldas. This study shows the presence of SRB in the analyzed environmental, as well as some factors that are related with the amount of SRB presents, such as: dissolved oxygen, pH and organic matter. ? 2005 Els

8、evier Ltd. All rights reserved.Keywords: Sulfate-reducing bacteria; Acid mine drainage1. IntroductionOne of the most serious environmental problems created by the mining industry is acid mine drainage. In one plant of Nu

9、clear Industries of Brazil—INB, this problem is a matter of concern. In that unit the uranium ore was pro- cessed until 1995 and generated a big amount of barren ore with U3O8 lower than 200 ppm. These barren ores were d

10、eposited in large neighboring areas from the mining re- gion, in waste rock piles The sulfite minerals present in these areas, including pyrite, generated high acidity water with radionuclides elements (uranium, thorium

11、and ra- dium) and stable elements (manganese, zinc, fluorite, iron,etc.). The level of these elements were above the environ- mental legislation content (Resoluc ¸a ?o CONAMA, 2005). Actually the treatment involves

12、chemical precipitation and any interruption leads to an increasing pollution on the aquatic system (Cipriani, 2002). The treatment of acid water using sulfate-reducing bacteria—SRB have been used in other countries with

13、quite good technical as well as economical results. SRB are useful to abate acid mine drainage—AMD due to two fundamental reasons. Firstly because of their capacity to reduce sulfate to sulfite. These sulfites react addi

14、tionally with certain metals dissolved in the contaminated waters, such as copper, iron and zinc, forming insoluble precipitates. On the other hand, the sys- tem acidity is reduced by their own action of sulfate reduc- t

15、ions and by the carbon metabolism of the bacteria (Garcia et al., 2001). In this context the objective of this study con- sisted in seasonal diagnostic of the sulfate-reducing bacte- ria present in the aquifer system of

16、the INB Industry Complex in Caldas, Brazil.0892-6875/$ - see front matter ? 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.mineng.2005.08.012* Corresponding author. Tel.: +55 31 34993316; fax: +55 31 34993399. E-m

17、ail addresses: jsb@cdtn.br (J.S. Benedetto), ska@cdtn.br (S.K. de Almeida), hgomes@cnen.gov.br (H.A. Gomes), vazoller@uol.com.br (R.F. Vazoller), acql@cdtn.br (A.C.Q. Ladeira).This article is also available online at: ww

18、w.elsevier.com/locate/minengMinerals Engineering 18 (2005) 1341–1343The medium values of SBR in water samples were low as we can see in Table 2. Some studies showed that high con- centrations of heavy metals and low pH v

19、alues (3.0–3.5) are limiting factors that influence the SRB increasing acid water from mine (Fro ¨mmichen et al., 2004; Garcia et al., 2001). The lowest pH value (below 3.5) was measured dur- ing the months of March

20、 and April and higher number of SRB (2.8 MPN mL?1) was detected in February in WR8 site when the water pH was higher (5.2). Anaerobic reac- tors studies for the metals and sulfites removing from mine acid water have show

21、n high SRB increasing, from 4.0 · 107to 8.0 · 108 bacteria mL?1 on acid medium mainly due to organic matter enrichment in these systems (Jong and Parry, 2003). According to expected results, the highest values

22、of SRB were detected in the period between February and August in water samples collected 12.5 m of depth in the PM, where it was also detected the lowest oxygen concentrations along the period. The dissolved oxygen valu

23、es measured in bot- tom samples of the mine lake (UTM) changed from 4.0 to 10.1 mg O2 L?1 and were according to the values obtained by Meier et al. (2004) using sediment/water interface sam- ples of acid water from Lusat

24、ia (Germany). The values of SRB as well as most of its occurrences in the sediment samples in the three sampling sites were high- er if compared with water samples along the year. This was expected as lower concentration

25、s of dissolved oxygen were found in the sediment and higher concentrations of avail- able organic matter for the populations of SRB were found in the sediment samples. These results are on a par with dif- ferent studies

26、conducted with acid water from mine.4. ConclusionThe results obtained from the microbiological variables presented seasonal variation in the three points evaluated.The results showed that SRB was present in water samples

27、 presenting low pH values and high concentrations of heavy metals, as well as in samples with high oxygen levels. The sediment was the preferential place for SRB occurrence and WR8 site presented the highest values of SR

28、B detected in that experimental study.AcknowledgmentsThe authors are grateful to FAPEMIG (Fundac ¸a ?o de Amparo a ` Pesquisa do Estado de Minas Gerais) for the financial support.ReferencesCipriani, M., 2002. Mitiga

29、c ¸a ?o dos impactos sociais e ambientais decor- rentes do fechamento definitivo de minas de ura ?nio. Doctor Thesis; Instituto de Geocie ?ncias, Universidade Estadual de Campinas, Cam- pinas/SP Brazil. Fro ¨mm

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31、D.A., Ballester, A., Bla ´zquez, M.L., Gonza ´lez, F., 2001. Bioremediation of an industrial acid mine water by metal- tolerant sulfate-reducing bacteria. Minerals Engineering 14 (9), 997– 1008. Jong, T., Parry

32、, D.L., 2003. Removal of sulfate and heavy metals by sulfate reducing bacteria in short-term bench scale upflow anaerobic packed bed reactor runs. Water Research 37 (14), 3379–3389. Meier, J.P., Baben Zien, H.D., Wendat

33、Potthoff, K., 2004. Microbial cycling of iron and sulfur in sediments of acidic and pH neutral mining lakes in Lusatia (Brandenburg, Germany). Biogeochemistry 67, 135– 156. Postgate, J.R., 1979. The Sulphate-Reducing Bac

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