Neutralization of Acid Mine Water with Calcium Carbonate

1994 ◽  
Vol 29 (9) ◽  
pp. 285-296 ◽  
Author(s):  
J. P. Maree ◽  
P. du Plessis
Keyword(s):  
Calcium Carbonate ◽  
Contact Time ◽  
Lower Cost ◽  
Free Acid ◽  
Pilot Scale ◽  
Fluidised Bed ◽  
Acid Mine Water ◽  
Ph Values ◽  
Fluidised Bed Reactor ◽  
Low Solubility

Traditionally, lime is used for the neutralization of acidic effluents. Calcium carbonate should be considered as an alternative because of considerations such as lower cost, low solubility at pH values greater than 7 and simple dosing system required. The paper describes a pilot scale study to determine the technical feasibility of neutralising sulphuric acid-rich water using fluidised bed technology. Limestone was utilised completely when testing iron(III)-rich water, but with iron(II)-rich water, coated limestone particles accumulated in the fluidised-bed reactor. About 70% of the limestone was utilised in the case of water containing 600 mg/l iron(II). A contact time of 4 min was sufficient for the neutralization of acid water containing 4 g/l free acid and 580 mg/l iron(III), compared to 40 min when iron(II) replaced iron(III).

Pilot-scale neutralisation of underground mine water

1996 ◽  
Vol 34 (10) ◽  
pp. 141-149 ◽  
Author(s):  
J. P. Maree ◽  
G. J. van Tonder ◽  
P. Millard ◽  
T. C. Erasmus
Keyword(s):  
Mine Water ◽  
Contact Time ◽  
Pilot Scale ◽  
Underground Water ◽  
Underground Mine ◽  
Economic Feasibility ◽  
Fluidised Bed ◽  
Chemical Composition Of Water ◽  
Before And After ◽  
Time Required

Traditionally acid mine water is neutralised with lime (Ca(OH)2). Limestone (CaCO3) is a cheaper alternative for such applications. This paper describes an investigation aimed at demonstrating that underground mine water can be neutralised with limestone in a fluidised-bed. The contact time required between the limestone and the acid water, chemical composition of water before and after treatment, and economic feasibility of the fluidised bed neutralisation process are determined. A pilot plant with a capacity of 10k1/h was operated continuously underground in a gold mine. The underground water could be neutralised effectively using the limestone process. The pH of the water was increased from less than 3 to more than 7, the alkalinity of the treated water was greater than 120 mg/l (as CaCO3) and the contact time required between mine water and limestone was less than 10 min (the exact contact time depends on the limestone surface area). Chemical savings of 56.4% can be achieved compared to neutralisation with lime.

Combustion of oil palm stone in a pilot-scale fluidised bed reactor

2011 ◽  
Vol 92 (12) ◽  
pp. 2219-2225 ◽  
Author(s):  
Raja Razuan ◽  
Qun Chen ◽  
Karen N. Finney ◽  
Nigel V. Russell ◽  
Vida N. Sharifi ◽  
...  
Keyword(s):  
Oil Palm ◽  
Pilot Scale ◽  
Fluidised Bed ◽  
Fluidised Bed Reactor

Pilot-scale culture ofCoffea arabica in a novel loop fluidised bed reactor

1995 ◽  
Vol 43 (2) ◽  
pp. 171-183 ◽  
Author(s):  
Beno�t Dubuis ◽  
Oemer M. Kut ◽  
Jiri E. Prenosil
Keyword(s):  
Pilot Scale ◽  
Fluidised Bed ◽  
Fluidised Bed Reactor

scholarly journals TREATMENT OF POME BY PILOT PLANT ANAEROBIC FLUIDISED BED REACTOR

2010 ◽  
Vol 9 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Abdullah Al-Mamun ◽  
Azni Idris
Keyword(s):  
Ambient Temperature ◽  
Pilot Plant ◽  
Loading Rate ◽  
Pilot Scale ◽  
Fluidised Bed ◽  
Detention Time ◽  
Start Up ◽  
Palm Oil Mill ◽  
Fluidised Bed Reactor ◽  
Fast Settling

A pilot scale anaerobic fluidised bed reactor (AnFBR) of 2000 L capacity was studied to determine its performance to treat palm oil mill effluent (POME). The pilot plant was operated at ambient temperature with diluted POME as substrate. It took 17 days for the start-up of the reactor with pre-seeded sand media. The AnFBR was capable to remove a large portion of organics at relatively shorter retention time. Maximum and minimum COD removal efficiency of 85% and 65% were attained at a loading rate of 4.0 and 13.8 kgCOD/m3.d. BOD and TSS removal rates varied within the range of 64% - 91% and 68% - 89%, respectively. The AnFBR exhibited low sludge production with lower sludge volume indices (SVI). Maximum and minimum effluent indices for the effluent were 35 mL/g and 11 mL/g, respectively. Low SVI values indicated that, anaerobic fluidised bed reactors generate less sludge with fast settling properties. Promising performance at ambient temperature and for detention time shorter than the present practices supported the possibility of AnFBR to treat POME to meet the new requirement set by the DOE Malaysia.

The Malachite Green Biodegradation in Bioreactors on Various pH Domains

2019 ◽  
Vol 70 (8) ◽  
pp. 2996-2999
Author(s):  
Viorel Gheorghe ◽  
Catalina Gabriela Gheorghe ◽  
Andreea Bondarev ◽  
Vasile Matei ◽  
Mihaela Bombos
Keyword(s):  
Malachite Green ◽  
Contact Time ◽  
Dominant Species ◽  
Wastewater Treatment Plants ◽  
Organic Substances ◽  
Biological Degradation ◽  
Growth Promoters ◽  
Ph Values ◽  
Biological Sludge ◽  
Ph Range

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

Effect of Physicochemical Variables on Algal Autoflotation

1992 ◽  
Vol 26 (7-8) ◽  
pp. 1769-1778 ◽  
Author(s):  
S.-I. Lee ◽  
B. Koopman ◽  
E. P. Lincoln
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Retention Time ◽  
Contact Time ◽  
Pilot Scale ◽  
Dissolved Oxygen Concentration ◽  
Physicochemical Variables ◽  
Rise Rate ◽  
Mixing Intensity ◽  
Maximum Rise

Combined chemical flocculation and autoflotation were examined using pilot scale process with chitosan and alum as flocculants. Positive correlation was observed between dissolved oxygen concentration and rise rate. Rise rate depended entirely on the autoflotation parameters: mixing intensity, retention time, and flocculant contact time. Also, rise rate was influenced by the type of flocculant used. The maximum rise rate with alum was observed to be 70 m/h, whereas that with chitosan was approximately 420 m/h. The efficiency of the flocculation-autoflotation process was superior to that of the flocculation-sedimentation process.

Effects of pressure on flow regimes transition velocities and bubble properties in a pilot-scale pressurised circulating fluidised bed

2021 ◽  
Vol 410 ◽  
pp. 128438
Author(s):  
Xiaoli Zhu ◽  
Pengfei Dong ◽  
Zhiping Zhu ◽  
Raffaella Ocone ◽  
Wuqiang Yang ◽  
...  
Keyword(s):  
Flow Regimes ◽  
Pilot Scale ◽  
Fluidised Bed ◽  
Circulating Fluidised Bed ◽  
Bubble Properties

Preparation and structural analysis of (±)-threo-ritalinic acid

2013 ◽  
Vol 69 (11) ◽  
pp. 1225-1228 ◽  
Author(s):  
Sara Wyss ◽  
Irmgard A. Werner ◽  
W. Bernd Schweizer ◽  
Simon M. Ametamey ◽  
Selena Milicevic Sephton
Keyword(s):  
Methyl Ester ◽  
Free Acid ◽  
Nmr Analysis ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
X Ray Crystallography ◽  
Ph Values ◽  
Ritalinic Acid ◽  
Methyl Phenidate ◽  
Hydrolysis Of

Hydrolysis of the methyl ester (±)-threo-methyl phenidate afforded the free acid in 40% yield,viz.(±)-threo-ritalinic acid, C13H17NO2. Hydrolysis and subsequent crystallization were accomplished at pH values between 5 and 7 to yield colourless prisms which were analysed by X-ray crystallography. Crystals of (±)-threo-ritalinic acid belong to theP21/nspace group and form intermolecular hydrogen bonds. An antiperiplanar disposition of the H atoms of the (HOOC—)CH—CHpygroup (py is pyridine) was found in both the solid (diffraction analysis) and solution state (NMR analysis). It was also determined that (±)-threo-ritalinic acid conforms to the minimization of negativegauche+–gauche−interactions.

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