WO2007085039A1 - Biodegradation of organic compounds - Google Patents
Biodegradation of organic compounds Download PDFInfo
- Publication number
- WO2007085039A1 WO2007085039A1 PCT/AU2006/000109 AU2006000109W WO2007085039A1 WO 2007085039 A1 WO2007085039 A1 WO 2007085039A1 AU 2006000109 W AU2006000109 W AU 2006000109W WO 2007085039 A1 WO2007085039 A1 WO 2007085039A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bayer circuit
- oxalate
- organic compounds
- bayer
- biodegradation
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/46—Purification of aluminium oxide, aluminium hydroxide or aluminates
- C01F7/47—Purification of aluminium oxide, aluminium hydroxide or aluminates of aluminates, e.g. removal of compounds of Si, Fe, Ga or of organic compounds from Bayer process liquors
- C01F7/473—Removal of organic compounds, e.g. sodium oxalate
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/18—Extraction of metal compounds from ores or concentrates by wet processes with the aid of microorganisms or enzymes, e.g. bacteria or algae
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/006—Wet processes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Definitions
- the present invention relates to a method for the anaerobic biodegradation of organic compounds in a Bayer circuit.
- the Bayer process is widely used for the production of alumina from aluminium containing ores such as bauxite.
- the process involves contacting alumina- containing ores with recycled caustic aluminate solutions at elevated temperatures, in a process commonly referred to as digestion.
- the sodium aluminate solution so produced also contains insoluble residues from the bauxite ore, and the solids are separated from the solution in a thickener or clarifier.
- the solids known as 'red mud', are taken as underflow from the thickeners, then typically washed to recover caustic values and render the mud suitable for disposal.
- the dense slurry is pumped to drying beds and distributed over a surface to allow the residue to dry atmospherically, with entrained caustic liquor being recovered via an underdrain system. The underdrain caustic liquor is recycled for further use in the Bayer circuit along with spent liquor from other locations in the circuit.
- organic compounds also known as Total Organic Carbon or TOC
- TOC Total Organic Carbon
- Benefits associated with removal of organic compounds from Bayer process solutions include a reduction in the amount of soda in the alumina product, reduced liquor viscosity and improved hydrate agglomeration.
- Subsidiary disadvantages associated with organic compounds of Bayer process solutions include reduced boiling point, foaming, liquor and hydrate absorbance and liquor density.
- Refineries employ several methods to reduce or control the levels of organic compounds in alkaline solutions in process liquor. These may include specific removal processes, controlled entrainment of liquor to residue disposal and natural loss associated with TOC adsorption onto product hydrate.
- Oxalate forms a substantial component of the overall TOC in process liquor. It builds up in the liquor stream as a result of direct input from bauxite and from the natural degradation of other organics as the liquor is continually recycled through the Bayer circuit.
- the invention presented herein was developed to provide an alternative method for the treatment of organic compounds from the Bayer circuit.
- solution or variations such as “solutions”, will be understood to encompass slurries, suspensions and other mixtures containing undissolved solids.
- alkaliphilic' will be understood to encompass a microorganism that can grow in alkaline solutions.
- TOC will be understood to refer to all organic compounds in Bayer process solutions.
- 'GC-TOC relates to those biodegradable compounds specifically identified by gas chromatography (hereinafter GC), namely formate, acetate, oxalate, malonate and succinate.
- GC gas chromatography
- 'OB-TOC will be understood to refer to biodegradable organic compounds not identified by GC.
- a method for the biodegradation of organic compounds in a Bayer circuit including the steps of:
- the portion of the Bayer circuit comprises an alkaliphilic microorganism and an electron acceptor and the microorganism is capable of anaerobic respiration in the presence of the electron acceptor,
- portion of the Bayer circuit to be treated will be any portion where the organic compounds are bioavailable to the microorganism.
- the organic compounds are provided in the form of formate, acetate, oxalate, malonate and/or succinate ions.
- the portion of the Bayer circuit has a pH of between about 9 and about 10.5.
- the Bayer circuit may be treated by any method known in the art to provide a pH of between about 8 and about 12, including carbonation and sea-water neutralisation.
- the portion of the Bayer circuit is carbonated.
- the portion of the Bayer circuit is provided in the form of a residue from the Bayer circuit.
- the Bayer circuit residue is provided in the form of a residue bed.
- the Bayer circuit residue is provided in the form of a superthickener, wherein the underflow from the superthickener is passed to the residue bed. It should be appreciated that the superthickener may not provide sufficient residence time for complete degradation of biodegradable organic compounds and that any degradation commenced in the superthickener may continue in the residue bed.
- portion of the Bayer circuit may comprise more than one species of naturally occurring microorganism.
- the method comprises the further step of:
- the method comprises the further step of:
- the method comprises the step of adding nutrients to the Bayer circuit
- the method preferably comprises the further step of:
- portion of the Bayer circuit to be treated will be any portion wherein the nutrients and/or trace elements are bioavailable to the microorganism.
- the nutrients comprise at least one of nitrogen, phosphorus, magnesium and iron and may be selected from the group comprising nitrates, urea, ammonia, phosphoric acid, mono ammonium phosphate, polyphosphates and yeast/meat extracts. It will be appreciated that the source of nutrients should make them bioavailable to the microorganisms.
- the nitrogen source is preferably a combination of ammonia, nitrate and urea.
- the nutrients comprise magnesium
- the magnesium source is preferably magnesium sulfate.
- the nutrients comprise iron
- the iron source is preferably iron sulfate.
- the electron acceptor is a source of at least one of nitrate (NOs “ ), nitrite (NO 2 " ), iron (Fe 3+ ), sulfate (SO 4 2” ), sulfur (S 0 ), or carbon dioxide (CO 2 ). It will be appreciated that the source of electron acceptor should make them bioavailable to the microorganisms. More preferably, the electron acceptor is in the form of sulfate or nitrate.
- the method of the present invention may be used to selectively degrade oxalate ions in preference to acetate ions.
- the method of the present invention may be used to control oxalate concentrations within a Bayer process circuit.
- the method of the present invention is preferably enhanced by increasing the residence time of solutions containing organic compounds in the residue.
- a method for the biodegradation of oxalate in a Bayer process residue including the steps of: treating a portion of the Bayer circuit to provide a pH of between about 8 and about 12 wherein the portion of the Bayer circuit comprises an alkaiiphilic microorganism and an electron acceptor and the microorganism is capable of anaerobic respiration in the presence of the electron acceptor; and
- the portion of the Bayer circuit has a pH of between about 9 and about 10.5.
- the Bayer circuit may be treated by any method known in the art to provide a pH of between about 8 and about 12, including carbonation and sea-water neutralisation.
- the portion of the Bayer circuit is carbonated.
- the portion of the Bayer circuit is provided in the form of a residue from the Bayer circuit.
- the Bayer circuit residue is provided in the form of a residue bed.
- the sand-diene circuit residue is provided in the form of a residue bed.
- Bayer circuit residue is provided in the form of a superthickener, wherein the underflow from the superthickener is passed to the residue bed. It should be appreciated that the superthickener may not provide sufficient residence time for complete degradation of biodegradable organic compounds and that any degradation commenced in the superthickener may continue in the residue bed.
- the oxalate is provided in the form of plant sodium oxalate cake, recovered from the Bayer process.
- portion of the Bayer circuit may comprise more than one species of naturally occurring microorganism.
- the method comprises the further step of: adding an electron acceptor to the Bayer circuit.
- the method comprises the further step of:
- the method comprises the step of adding nutrients to the Bayer circuit
- the method preferably comprises the further step of:
- portion of the Bayer circuit to be treated will be any portion wherein the nutrients and/or trace elements are bioavailable to the microorganism.
- the nutrients comprise at least one of nitrogen, phosphorus, magnesium and iron and may be selected from the group comprising nitrates, urea, ammonia, phosphoric acid, mono ammonium phosphate, polyphosphates and yeast/meat extracts. It will be appreciated that the source of nutrients should make them bioavailable to the microorganisms.
- the nitrogen source is preferably a combination of ammonia, nitrate and urea.
- the nutrients comprise magnesium
- the magnesium source is preferably magnesium sulfate.
- the nutrients comprise iron
- the iron source is preferably iron sulfate.
- the electron acceptor is a source of at least one of nitrate (NO 3 " ), nitrite (NO 2 ' ), iron (Fe 3+ ), sulfate (SO 4 2” ), sulfur (S 0 ), or carbon dioxide (CO 2 ). It will be appreciated that the source of electron acceptor should make them bioavailable to the microorganisms.
- the electron acceptor is in the form of sulfate or nitrate.
- the method of the present invention may be used to control oxalate concentrations within a Bayer process circuit.
- the method of the present invention is preferably enhanced by increasing the residence time of solutions containing oxalate in the residue.
- a method for the control of oxalate in a Bayer circuit including the steps of:
- the portion of the Bayer circuit comprises an alkaliphilic microorganism and an electron acceptor and the microorganism is capable of anaerobic respiration in the presence of the electron acceptor;
- the portion of the Bayer circuit has a pH of between about 9 and about 10.5.
- the Bayer circuit may be treated by any method known in the art to provide a pH of between about 8 and about 12, including carbonation and sea-water neutralisation.
- the Bayer circuit is carbonated.
- the portion of the Bayer circuit is provided in the form of a residue from the Bayer circuit.
- the Bayer circuit residue is provided in the form of a residue bed.
- the sand-diene circuit residue is provided in the form of a residue bed.
- Bayer circuit residue is provided in the form of a superthickener, wherein the underflow from the superthickener is passed to the residue bed. It should be appreciated that the superthickener may not provide sufficient residence time for complete degradation of biodegradable organic compounds and that any degradation commenced in the superthickener may continue in the residue bed.
- portion of the Bayer circuit may comprise more than one species of naturally occurring microorganism.
- the method further comprises the further step of:
- the method further comprises the further step of:
- the method comprises the step of adding nutrients to the Bayer circuit
- the method preferably comprises the further step of:
- portion of the Bayer circuit to be treated will be any portion wherein the nutrients and/or trace elements are bioavailable to the microorganism.
- the nutrients comprise at least one of nitrogen, phosphorus, magnesium and iron and may be selected from the group comprising nitrates, urea, ammonia, phosphoric acid, mono ammonium phosphate, polyphosphates and yeast/meat extracts. It will be appreciated that the source of nutrients should make them bioavailable to the microorganisms.
- the nitrogen source is preferably a combination of ammonia, nitrate and urea.
- the nutrients comprise magnesium
- the magnesium source is preferably magnesium sulfate.
- the nutrients comprise iron
- the iron source is preferably iron sulfate.
- the electron acceptor is a source of at least one of nitrate (NO 3 ' ), nitrite (NO 2 " ), iron (Fe 3+ ), sulfate (SO 4 2" ), sulfur (S 0 ), or carbon dioxide (CO 2 ). It will be appreciated that the source of electron acceptor should make them bioavailable to the microorganisms.
- the electron acceptor is in the form of sulfate or nitrate.
- the method of the present invention may be used to selectively degrade oxalate ions in preference to acetate ions.
- the method of the present invention may be used to control oxalate concentrations within a Bayer process circuit. Where the portion of the Bayer circuit is provided in the form of a Bayer circuit residue, the method of the present invention is preferably enhanced by increasing the residence time of solutions containing organic compounds in the residue.
- Figure 1a is a schematic flow sheet showing how a method in accordance with a first embodiment of the present invention may be utilised in a Bayer Process circuit
- Figure 1b is a schematic flow sheet showing how a method in accordance with a second embodiment of the present invention may be utilised in a Bayer Process circuit
- Figure 2 is a schematic flow diagram of a bench trial pilot plant
- Figure 3 is a plot of the concentration of organic species in sand column 1 ;
- Figure 4 is a plot of the concentration of organic species in sand column 2;
- Figure 5 is a plot of the concentration of organic species in sand column 3.
- Figure 6 is a plot of the concentration of organic species in sand column 1.
- FIG. 1a shows a schematic flow sheet of the Bayer process circuit 10 comprising the steps of:
- the residue 18 is carbonated 30 to reduce the pH to about 10.5 and the carbonated residue passed to the residue bed.
- Naturally occurring microorganisms in the residue then biodegrade organic compounds in the residue.
- FIG. 1a shows a schematic flow sheet of the Bayer process circuit 10 comprising the steps of:
- plant oxalate cake 38 as a concentrated slurry of sodium oxalate is added to the carbonation tank along with the residue and the carbonated residue passed to the residue bed.
- the residue In a standard Bayer circuit, the residue is known to contain amounts of oxalate, notwithstanding processes to remove the oxalate. In an uncarbonated residue bed, some of the oxalate returns to the Bayer circuit via the residue bed underdrain system. Depending on residence time and moisture, up to 40 % of the oxalate entering the bed may be returned to the circuit, with the balance of the oxalate remaining in the residue. If the residue is carbonated, it is believed that, given sufficient residence time and the availability of appropriate electron acceptor, and under certain circumstances, nutrient addition, all of the oxalate in the residue may be degraded.
- the method may be used to dispose of plant oxalate. Based on experimental information, it is believed that the oxalate concentration in the bed may be increased at least four times and with appropriate holding time and the availability of appropriate electron acceptor, and under certain circumstances, nutrient addition, all of the oxalate in the residue may be degraded.
- the concentrations of formate, acetate, oxalate, malonate and succinate in influent and effluent liquors were determined using a Hewlett Packard 5890 Gas Chromatograph equipped with a Supelcowax capillary column (60 m x 0.2 mm x 0.2 ⁇ m) and flame ionisation detector.
- TOC Total Organic Carbon
- the liquor had low pH and was chosen to represent a lakewater containing a natural population of TOC degrading microorganisms, which are preferably anaerobic and/or facultatively anaerobic.
- Some typical effluent liquor values are shown in Table 3.
- Table 1 Particle size distribution of sand sample.
- Test liquor was transferred from a storage tank to influent liquor storage tanks located in a cool room. At this time if required under the experimental conditions, a nutrient and trace metal solution was added to the influent storage tanks and mixecl thoroughly. The temperature of the refrigerated cool room was maintained at 9 0 C to inhibit microbial growth and thus TOC degradation occurring in the influent liquor prior to its application to the sand columns.
- the influent liquor was filtered through a 5 ⁇ m in-line filter to remove any precipitated compounds prior to addition to the sand columns.
- the influent liquor was added to the top of each sand column using a Grundfos positive displacement dosing pump that could deliver a constant influent liquor flow rate in a range from 0 to 2.5 L/hr.
- the influent liquor flow rate was set at 120 mL/hr, providing a 14 day residence time in each of the sand columns. (The calculated residence time in the residue sand layer being about 45 days based on sand layer saturation level, underdrain flow rate and sand layer area/depth.
- the influent flow rate was monitored periodically and the settings on the pump controller were adjusted accordingly.
- the columns were housed in a climate controlled room set to maintain the temperature at, typically, 20 0 C; similar to that of the underdrain system.
- Lakewater was carbonated using CO 2 , the precipitated alumina solids allowed to settle overnight and the supernatant pumped into a separate holding tank.
- Plant sodium oxalate cake typically contains 40 % wt / wt sodium oxalate with the remainder consisting of Bayer liquor of a varying composition.
- Test liquor with oxalate concentration of 2.5 g/L was chosen to represent a Bayer circuit liquor from a superthickener underflow and test liquor with oxalate concentration of 10 g/L was chosen to represent the underflow liquor with additional oxalate added. The latter test was intended to represent the situation that would be encountered under oxalate disposal conditions.
- a nutrient and trace metal solution was added to the influent liquor in the influent liquor storage tanks for a number of the trials.
- the nutrient target concentration in the influent liquor was based on the assumptions that 5 % of the total biodegradable TOC was used for biomass production, and the ratio of carbon, nitrogen and phosphorus in biomass was Cio ⁇ NieP-i.
- the nutrient and trace metal solution contained Metals 44/Modified MSB solution without the addition of nitriliotriacetic acid, and with the addition of 32 g/L NH 4 CI and 3.7 g/L H 3 PO 4 as a source of N and P, respectively.
- the nutrient and trace metal solution was added to the influent feed liquor at a rate of 1 mL/L, giving a final concentration of 0.0319 g/L NH 4 CI (8.42 mg/L as N) and 0.0037 g/L -H 3 PO 4 (1.18 mg/L as P) (see Tables 4 and 5).
- the nutrient and trace metal solution was modified by replacing 32 g/L NH 4 CI with 48.1 g/L NH 4 NO 3 , which gave a final concentration of 0.0481 g/L NH 4 NO 3 (16.8 mg/L as total N, 8.42 mg/L as N from nitrate).
- the use of NH 4 NO 3 ensured that N from the nitrate would be available to the biomass within the sand column.
- the pKa of NH 3 is 9.3. At pH 10.3, 91% exists as NH 3 and is likely to volatilise before leaching into the sand column.
- nitrate reduction would occur in preference to sulfate reduction. If nitrate reduction occurs within the sand columns, the NH 3 produced would not volatilise under the hydraulic flow of the column and would most likely still be available as a nitrogen source for sulfate-reducing bacteria further down the sand column.
- the total amount of nitrate added to the sand column would only support a small proportion of the biodegradable organic compounds in the liquor being oxidised under a nitrate- reducing pathway, so a nitrate-reducing microbial population would not outcompete the growth of sulfate-reducing microorganisms.
- the nutrient and trace metal solution was added to the influent feed liquor at a rate of 2.3 mL/L, giving a final concentration of 0.1106 g/L NH 4 NO 3 (38.7 mg/L as total N, 19.37 mg/L as N from nitrate) and 0.0085 g/L H 3 PO 4 (2.71 mg/L as P).
- the final concentrations of metals in both low and high oxalate influent liquors are given in Table 6.
- the sand columns were situated in a temperature controlled room at 20 0 C, the temperature chosen to approximate the average temperature which would be expected within the residue area.
- a Gastec gas pump and Drager tube were used to determine whether the volatile gases SO 2 , H 2 S and NH 3 were present in the anaerobic column room and/or within each of the sand columns.
- a Drager tube a specific colour indicator tube for each of the above gases, was fitted to the gas pump. Volumes of air were drawn into the tube from various points within the anaerobic column room. For the detection of the gases from the sand column effluents, the Drager tube was inserted into the effluent tube of each column and volumes of air were drawn into the tube.
- concentrations of free sulfide (as S 2' ) and total sulfide (S 2" and polysulfides) in the effluents of sand columns 1 , 2 and 3 were determined by sulfide titration.
- a reduction in the concentration of sulfate and the presence of sulfides in the effluents is an indication that sulfate reduction has occurred.
- concentrations of free sulfide (as S 2" ) and total sulfide (S 2" and polysulfides) in the effluents of sand columns 1 , 2 and 3 were determined by titration.
- the final titrated solution should have an alkalinity of at least 1 M NaOH. Any autotitrator capable of finding the end point differentially is suitable, such as the Mettler DL-70.
- the electrode response is slow when the concentration of sulfide is below 1 ⁇ g/mL in the titrated solution. Therefore, parameters must be set to allow sufficient time for the particular electrode to respond to each addition of silver.
- Other halogens do not interfere with quantification of free sulfide but iodide must be absent or allowed for by standard addition if partially oxidised forms of sulfide, such as polysulfides, are titrated. Other compounds which complex with silver or sulfide such as cyanide and mercury may interfere.
- the concentration of sulfide was determined from 1 mL of 0.02821 M AgNO 3 is equivalent to 1.100 mg Na 2 S or 0.4523 mg S 2" .
- carbonated lakewater (a low pH -10-10.5 with an alkalinity in the range of ⁇ 20- 30 g/L as Na 2 CO 3 , which contains ⁇ 2-2.5 g/L sodium sulfate, and formate, acetate, oxalate, malonate and succinate, and other organic compounds in varying concentrations) was supplied to sand columns 1 and 2 at an influent flow rate of 120 mL/min, in the absence of and with the addition of nutrients respectively. The sand columns were operated under these conditions for 146 days for column 1 and 132 days for column 2 (Tests 1a and 2a of Table 7 and Figures 3 and 4).
- the concentration of acetate in the effluent from sand column 1 was greater than its concentration in the influent from approximately day 64 onwards.
- the concentration of acetate in the effluent of sand column 1 increased over time, reaching as high as 23% greater than its concentration in the influent by day 139. This suggested that fermentation of organic compounds was occurring within the sand column while the population of sulfate-reducing bacteria was establishing.
- Acetate was also produced in sand column 2 over the first 133 days. The difference in the concentration of acetate between the influent and effluent at days
- the influent flow rate was halved from 120 to 60 mL/hr on days 147 and 133 for sand columns 1 and 2 respectively, increasing the residence time within each sand column from approximately 14 to 28 days (Tests 1 b and 2b, Table 7).
- the increase in the residence time had an immediate effect on the concentration of oxalate in the effluents of both sand columns 1 and 2, with oxalate being completely degraded within 29 days after the change in influent flow rate. There was no difference in the rate of oxalate degradation between columns 1 and 2, which suggested that the residence time had a greater impact on oxalate degradation than nutrient addition. The results also showed that the addition of nutrients were not essential for the degradation of oxalate, but reduced the time required to commence oxalate degradation by increasing the growth rate and establishment of a sulfate-reducing microbial population.
- the increase in the concentration of oxalate in the effluent from sand column 2 on day 188 was believed to be a result of a blockage in the influent pump which occurred approximately two weeks earlier, on day 176.
- the concentration of oxalate in the influent increased from 2.31 to 2.64 g/L at this time, as a result of cleaning the pump, however, the surge in oxalate concentration in the effluent was believed to be from a disturbance with the biomass, as the concentration of sulfate followed the same trend as that for oxalate.
- Nutrient addition may not only increase the rate of degradation of TOC but may also have an effect on the metabolic pathways of organic acid degradation by enhancing the growth rate and establishment of a population of bacteria that can respire anaerobically. Without being limited by theory, it is believed that fermentation of organic compounds occurs, resulting in the production of acetate and other simple organic acids, and once a population of sulfate-reducing bacteria has reached certain threshold population density, the products of fermentation are degraded through anaerobic respiration. The addition of nutrients is believed to enhance the growth rate of microorganisms capable of anaerobic respiration and hence increase the rate of degradation of organic compounds.
- Residence time had a greater impact on oxalate degradation than the addition of nutrients. Without being limited by theory, it is believed that this could have been due to the dilution of a compound which had toxic effects on the growth of biomass, as when the residence time was reduced, degradation of organic compounds (oxalate) was maintained.
- Acetate production in sand columns 1 and 2 could not be quantified due to changes in acetate concentration in the influent with fresh batches, and the residence time difference within the sand columns.
- acetogenesis which involves the reduction of CO 2 to acetate by H 2 .
- Organic acids can also act as electron donors in addition to H 2 .
- acetogenesis generally does not occur in the presence of sulfate-reducing bacteria.
- the pH of the influent liquor was found to be pH 9.5, which was most likely the reason for the degradation of oxalate, as it provided a more favourable environment for the growth of sulfate-reducing bacteria.
- 10 g/L oxalate had almost completely degraded within the sand column and the concentration of sulfate had reduced by 88 %.
- Test 3a showed that 10 g/L oxalate could be completely degraded within the sand column with the addition of nutrients at a flow rate of 120 mL/min. A small amount of acetate appeared to have been produced prior to oxalate degradation, but was not quantified. Once oxalate had completely degraded, the concentration of acetate in the effluent fluctuated and followed the same trend as that of the influent with its concentration generally lower, but it was not degraded. It was possible that either the amount of nutrients provided in the influent was only sufficient for oxalate degradation or that oxalate-degrading bacterium dominated the sand column due to the high concentration of oxalate.
- the test also showed that gas production occurred and that the retention time within the column has a great effect on whether oxalate is completely degraded or not.
- sand column 1 was operated with high concentration oxalate liquor and no additional nutrients, as a continuation from Test 1 b.
- the flow rate was increased from 60 mL/hr to 120 mL/hr and the concentration of oxalate in the influent liquor was approximately 10.5 g/L. This resulted in the mass of oxalate per unit volume to the sand column increasing by a factor of 8 from the previous test.
- a Drager tube was used to determine whether sulfur dioxide, hydrogen sulfide and/or ammonia could be measured in the anaerobic column room or directly from the columns.
- Ammonia could be detected after multiple samples of air were drawn directly from the effluent tubes from sand columns 2 and 3, but not from sand column 1. Given that the influent liquor to sand columns 2 and 3 contained a nutrient solution as a source of ammonia, this result was to be expected. The only possible source of ammonia is from the nutrient, ammonium nitrate. This could occur directly from ammonium nitrate, or from the anaerobic reduction of nitrate.
- the gases could not be quantified since the volume of ambient air that was mixed with emitted gases was not controlled and is highly dependant on the sampling location.
- the concentrations of free sulfide (as S 2" ) and total sulfide (S 2" and polysulfides) in the effluents of sand columns 1 , 2 and 3 are shown in Table 8.
- the results show that the concentrations of sulfide in the effluents of the anaerobic sand columns are much less than the concentration expected from the reduction of approximately 2.5 g/L sulfate, indicating that the majority of sulfide produced has precipitated as metal sulfides.
- the effluents contained fine black particulates, which were believed to be metal sulfides.
- anaerobic processes may be used to completely degrade high concentrations of oxalate (10 g/L). IF anaerobic conditions are provided in a residue bed with a suitable pH, such as a carbonated residue bed, it is possible to biodegrade oxalate through incorporation with carbonated residue disposal.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/AU2006/000109 WO2007085039A1 (en) | 2006-01-30 | 2006-01-30 | Biodegradation of organic compounds |
AU2006337051A AU2006337051A1 (en) | 2006-01-30 | 2006-01-30 | Biodegradation of organic compounds |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/AU2006/000109 WO2007085039A1 (en) | 2006-01-30 | 2006-01-30 | Biodegradation of organic compounds |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2007085039A1 true WO2007085039A1 (en) | 2007-08-02 |
Family
ID=38308772
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/AU2006/000109 WO2007085039A1 (en) | 2006-01-30 | 2006-01-30 | Biodegradation of organic compounds |
Country Status (2)
Country | Link |
---|---|
AU (1) | AU2006337051A1 (en) |
WO (1) | WO2007085039A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101913614A (en) * | 2010-07-12 | 2010-12-15 | 河南省岩石矿物测试中心 | Method for removing silicon in bauxite by using microorganisms |
WO2012094696A1 (en) * | 2011-01-14 | 2012-07-19 | Alcoa Of Australia Limited | Process for the destruction of organics in bayer process streams |
WO2019169441A1 (en) * | 2018-03-06 | 2019-09-12 | Environmental Engineers International Pty Ltd | Method for remediating industrial wastewater |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991012207A1 (en) * | 1990-02-13 | 1991-08-22 | Worsley Alumina Pty. Limited | Biological disposal of oxalates |
WO1994006719A1 (en) * | 1992-09-11 | 1994-03-31 | Alcan International Limited | Improvements in processes for the alkaline biodegradation of organic impurities |
AU5077893A (en) * | 1992-11-17 | 1994-06-02 | Bhp Billiton Worsley Alumina Pty Ltd | Hydrate precipitation and oxalate removal |
-
2006
- 2006-01-30 WO PCT/AU2006/000109 patent/WO2007085039A1/en active Application Filing
- 2006-01-30 AU AU2006337051A patent/AU2006337051A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1991012207A1 (en) * | 1990-02-13 | 1991-08-22 | Worsley Alumina Pty. Limited | Biological disposal of oxalates |
WO1994006719A1 (en) * | 1992-09-11 | 1994-03-31 | Alcan International Limited | Improvements in processes for the alkaline biodegradation of organic impurities |
AU5077893A (en) * | 1992-11-17 | 1994-06-02 | Bhp Billiton Worsley Alumina Pty Ltd | Hydrate precipitation and oxalate removal |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101913614A (en) * | 2010-07-12 | 2010-12-15 | 河南省岩石矿物测试中心 | Method for removing silicon in bauxite by using microorganisms |
WO2012094696A1 (en) * | 2011-01-14 | 2012-07-19 | Alcoa Of Australia Limited | Process for the destruction of organics in bayer process streams |
AU2011355589B2 (en) * | 2011-01-14 | 2015-07-30 | Alcoa Of Australia Limited | Process for the destruction of organics in bayer process streams |
WO2019169441A1 (en) * | 2018-03-06 | 2019-09-12 | Environmental Engineers International Pty Ltd | Method for remediating industrial wastewater |
AU2019230457A1 (en) * | 2018-03-06 | 2020-04-30 | Environmental Engineers International Pty Ltd | Method for remediating industrial wastewater |
AU2019230457B2 (en) * | 2018-03-06 | 2020-07-09 | Environmental Engineers International Pty Ltd | Method for remediating industrial wastewater |
Also Published As
Publication number | Publication date |
---|---|
AU2006337051A1 (en) | 2007-08-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN100491276C (en) | Combined treatment process for high-concentration ammonia nitrogen waste water | |
Le et al. | Phosphorus and potassium recovery from human urine using a fluidized bed homogeneous crystallization (FBHC) process | |
US4522723A (en) | Process for the removal and recovery of heavy metals from aqueous solutions | |
US4519913A (en) | Process for the removal and recovery of selenium from aqueous solutions | |
US4519912A (en) | Process for the removal of sulfate and metals from aqueous solutions | |
JPS5929317B2 (en) | Wastewater treatment method | |
US10059610B2 (en) | Reduction of the amount of sulphur compounds in a sulphur compounds contaminated wastewater stream using a granular sludge treatment system | |
JP2007283223A (en) | Method for recovering phosphorus from sludge | |
JP4925208B2 (en) | Aerobic granule formation method, water treatment method and water treatment apparatus | |
EP0436254A1 (en) | Treatment of aqueous waste streams | |
CA2127437C (en) | Cyanide recycling process | |
US6210589B1 (en) | Process for removing fluoride from wastewater | |
Maree et al. | Neutralizing coal mine effluent with limestone to decrease metals and sulphate concentrations | |
WO2007085039A1 (en) | Biodegradation of organic compounds | |
EP3539930B1 (en) | Method for supplying activated carbon slurry | |
CA2647965C (en) | Nickel sulphide precipitation processes | |
AU654449B2 (en) | Process for the removal of phosphorous | |
KR20110109914A (en) | Material for decontaminating water containing nitrate nitrogen, and method for decontaminating water containing nitrate nitrogen | |
Maree et al. | Neutralization of acid mine water and sludge disposal | |
JP2005040739A (en) | Phosphate-containing wastewater treatment method | |
JP2002326088A (en) | Method and apparatus for treating phosphorous and cod- containing water | |
Maree et al. | Limestone neutralisation of acidic effluent, including metal and partial sulphate removal | |
JPS60168587A (en) | Fluidized bed type catalytic dephosphorization | |
JP2657712B2 (en) | How to regenerate activated carbon | |
JP2009039637A (en) | Method for purifying cyanide-containing wastewater |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2006337051 Country of ref document: AU |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1561/MUMNP/2008 Country of ref document: IN |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 2006337051 Country of ref document: AU Date of ref document: 20060130 Kind code of ref document: A |
|
WWP | Wipo information: published in national office |
Ref document number: 2006337051 Country of ref document: AU |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 06704794 Country of ref document: EP Kind code of ref document: A1 |