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Bioremediation of acid mine drainage using decomposable plant material in a constant flow bioreactor 总被引：1，自引：0，他引：1
Under stagnant conditions, the ability of 15 earth materials (non-lime) including various inorganic 2:1 and 1:1 layer silicates, an amorphous oxide, and two 'whole' soils were tested for their pH-buffering efficiency in an acid mine drainage (AMD) water. The purpose was to decrease AMD acidity to a level where sulfate-reducing bacteria (SRB) placed in it may be activated. Of all materials, a whole soil (a high cation-exchange capacity clayey mollisol containing 40% clay, and 4% soil organic matter) caused the greatest pH increases from 2.5 up to 5.5 units after 10 days in the AMD water. Influent AMD was then ameliorated at various speeds through an SRB driven bioreactor using a 50/50 weight over weight (w/w) combination of the mollisol and ryegrass (MR) as the pH buffer substrate. This substrate combination decreased the SRB acclimatisation period (from 50 days in a previous experiment utilising sludge + ryegrass) to <10 days in the present experiment. After causing pH increases from 2.8 to >6 units in 5 days, the buffer reduced the hydraulic retention time (HRT) of the constant-flow reactor from 12 days at flow speeds of 100 ml/day to 2 days at 25 ml/day, respectively. After 10 days, soluble Fe, Al and sulfate were all decreased >1,800-, >40- and 3-fold, respectively. This was a more efficient performance than the no-flow bioreactor of a previous experiment using sludge + ryegrass. This method of AMD rehabilitation is an alternative for localities that lack cheap sources of calcium compounds for chemical treatment, but have a similar soil type and copious quantities of fresh decomposable plant wastes. 相似文献
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Bacterial mitigation of pollutants in acid drainage using decomposable plant material and sludge 总被引：2，自引：0，他引：2
Effects of a clay-lime spiked sewage sludge and fresh decomposable ryegrass on the mitigation of an acid drainage were studied
in the laboratory. Treatments (dry ameliorant weight/leachate ratio) were: (1) sludge (air-dried) at rates of 0, 8, 16 and
24%, (2) ryegrass at 0, 1, 1.5 and 2% (dry weight), (3) sludge (at the above-mentioned rates) and 1.5% ryegrass mixture. Measurements
of mitigation (according to the criteria of changes in pH, Fe, S, Al and heavy metals) made every 10th day for 100 days showed
ryegrass/sludge combination the most effective while sustaining mitigation longest, with or without the influence of sulphate-reducing
bacteria (SRB). Sulphate and Fe in the acid drainage decreased in the order: sludge+ryegrass>sludge>ryegrass by 180, 40, 19;
and 96, 83 and 54% respectively, compared with controls. An 11-fold decrease in soluble Al was caused by the highest rate
of the combined sludge-ryegrass treatment but Al was doubled by the sludge-only treatment, and only minimally affected (2%
reduction) by the ryegrass-only treatment. For the sludge plus ryegrass treatments at the highest rate of application, pH
levels increased significantly, from 2.3 to >7 units and within 20 days of SRB activation, the concentration of Co, Cu, Mn,
Ni and Zn decreased 3-, 15-, 90-, 3- and 50-fold respectively.
Received: 30 March 1999 · Accepted: 31 January 2000 相似文献
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Jérémy Ragusa Lina Maria Ospina-Ostios Silvia Spezzaferri Pascal Kindler 《Swiss Journal of Geoscience》2018,111(3):461-473
The ages obtained from planktonic foraminiferal assemblages retrieved from two exposures in the Gurnigel Flysch and from the re-examination of similar material gathered by previous researchers from the Voirons Flysch reveal only minor discrepancies with previous studies based on nannofossil biostratigraphy. In contrast, major divergences between this work and previous studies on the Voirons Flysch also based on planktonic foraminifera have been identified. They are generally related to distinct approaches in species classification and the use of different zonal schemes. Based on our data, the age of the Voirons Flysch extends from the Early Eocene (planktonic foraminiferal zone P7) to the Middle Eocene (planktonic foraminiferal zone P12). Contrasting with claims made in earlier studies, no specimen of Late Eocene or Early Oligocene age has been observed in the revised material. However, we cannot exclude a younger age (possibly Late Eocene) for the upper portion of this flysch from which we did not revise any sample. Thus, more research and sampling are needed to resolve this question. The palaeogeographic origin of the Voirons-Wägital complex as well as the sedimentation history of these flyschs need now to be re-evaluated in light of this revised biostratigraphic data. 相似文献
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Ragusa Jérémy Kindler Pascal Segvic Branimir Ospina-Ostios Lina Maria 《International Journal of Earth Sciences》2017,106(8):2619-2651
International Journal of Earth Sciences - The Chablais Prealps (Haute-Savoie, France) represent a well-preserved accretionary wedge of the Western Alpine Tethys. They comprise a stack of... 相似文献
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