Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01C—PLANTING; SOWING; FERTILISING
  • A01C3/00—Treating manure; Manuring
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
  • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
• • C—CHEMISTRY; METALLURGY
  • C05—FERTILISERS; MANUFACTURE THEREOF
  • C05F—ORGANIC FERTILISERS NOT COVERED BY SUBCLASSES C05B, C05C, e.g. FERTILISERS FROM WASTE OR REFUSE
  • C05F3/00—Fertilisers from human or animal excrements, e.g. manure
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/20—Nature of the water, waste water, sewage or sludge to be treated from animal husbandry
• • 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
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
  • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
  • Y02A40/20—Fertilizers of biological origin, e.g. guano or fertilizers made from animal corpses
• • 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
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/141—Feedstock
  • Y02P20/145—Feedstock the feedstock being materials of biological origin

Definitions

• This invention relates to the treatment of piggery effluent .
• Piggery effluent is generally high in phosphorus and if discharged without treatment will contaminate ground water, rivers, lakes and the like by encouraging the growth of algae and other aquatic plants.
• Various processes for treating the effluent have been considered but most are too costly to implement on a commercial scale. For example, raw effluent has been treated by the addition of lime but because of the quantity of lime required the cost is prohibitive.
• solid lime is added to the settling tank and mixed with the fines.
• a lime sludge is formed and after settling thereof the liquid may be discharged or used for irrigation.
• the solids removed by the screening and settling and the lime sludge may be used as fertiliser.
• the quantity of lime required to treat the recycled effluent is consider ⁇ ably less than that required to treat non-recycled effluent.
• the invention resides in a process for treating piggery effluent to reduce the phosphorus content comprising screening the effluent to remove the larger solid particles, separating the remaining fine solids by settling, recycling portion of the supernatant liquid through the piggery as flushing liquid whilst keeping the addition of fresh water to the system to a minimum, screening the recycled effluent to remove the larger solid particles, mixing the separated liquid and fines supernatant liquid with solid lime, separating the lime sludge formed and discharging the separated liquid to waste or irrigation.
• Fig.l is a diagrammatic representation of a first embodiment of the process
• Fig.2 is a graph showing the results of treatment of liquid from various stages of the process with two different types of lime.
• Fig.3 is a diagrammatic representation of a further process clarifying the liquid before discharge to waste.
• the effluent from the sheds 11 is passed into a sump 12 from where it is passed through a screen 13 to remove the larger solids.
• the sepa ⁇ rated liquid with the entrained fines is then passed to a settling tank 14.
• the substantially clear supernatant liquid flowing over the top of the tank 14 is passed to a tank 15 from where it is recycled as flushing liquid.
• the recycled liquid again passes through the sump 12 and the screen 13 to remove any larger solid particles picked up during flushing.
• the separated liquid passes to the settling tank 14.
• the number of times the effluent liquid is recycled will be gov ⁇ erned by the size of the piggery and the amount of phosphorus can be retained by the solid particles.
• solid lime in the form of lime kiln dust or hydrated lime is added to the tank 14 and mixed with the liquid and fines therein.
• the mixture is passed to a settling tank 16.
• a lime sludge is formed and settles to the bottom of the tank 16.
• Substantially clear liquid is withdrawn from the vesseL 16 and discharged to waste or used for irrigation.
• the lime sludge is dewatered and dried and may be used as fertiliser.
• the larger solids removed by the screen 13 may be mixed with the lime sludge if desired, or used separately as a fertiliser.
• the lime was added as it entered the vessel 14.
• a pump was used to mix the lime and effluent thoroughly and pump it to the settling tank 16 and allowed to settle overnight (16- 20 hours).
• Samples of the screened solids, primary waters (Prim- those which had been through the piggery once only), recycled (Pre primary waters which had been recycled through the piggery a number of times), and treated waters (Post- supernatant after settling) were taken and analysed for total phosphorus (TP) and total dissolved phospherus (DP). Total solid phosphorus was estimated by the difference.
• Any unsettled floes of lime, which may contain phos ⁇ phorus and entrained in the liquid discharged from the settling tank 16, may be removed by utilising the embodiment of the process illustrated diagrammatically in Fig.3 of the drawings.
• the liquid passing from the settling tank 16 containing the floes of lime is mixed with sand, primary flocculant and polyelectrolyte in the vessel 17, utilising the techniques disclosed in Australian Patent Specification No.22673/88.
• the sand may be recycled.

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Soil Sciences (AREA)
• Environmental Sciences (AREA)
• Inorganic Chemistry (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Removal Of Specific Substances (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=25637008

Family Applications (1)

Country Status (3)

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Citations (1)

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• 1991
  • 1991-01-29 AU AU72333/91A patent/AU7233391A/en not_active Abandoned
  • 1991-01-29 EP EP19910903732 patent/EP0464193A4/en not_active Withdrawn
  • 1991-01-29 WO PCT/AU1991/000032 patent/WO1991011393A1/fr not_active Ceased

Patent Citations (1)

Non-Patent Citations (1)

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