Classifications

• • 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
  • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
• • 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
  • C02F1/28—Treatment of water, waste water, or sewage by sorption
  • C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
• • 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
  • C02F1/58—Treatment of water, waste water, or sewage by removing specified dissolved compounds
  • C02F1/586—Treatment of water, waste water, or sewage by removing specified dissolved compounds by removing ammoniacal nitrogen

Definitions

• the invention relates to a process for the purification of industrially agricultural or private waste water from their impurities ammonium compounds and, in connection therewith, the phosphate compound and optionally heavy metals.
• the "ammonia stripping" process has become known is expelled by alkalinization of the waste water the Ammoniu in the form of ammonia from the waste water and washed out from the stripping gas by means Saur.
• the ammonium is separated from the waste water by ions
• ammonium impurities are separated in two stages by nitrification and denitrif Decoration in such a way that the ammonium remaining in the wastewater after biological purification is oxidized to nitrate by eight bacteria using special bacteria and then anaerobically reduced in the middle of other bacterial strains over a further four to five treatment steps elemental nitrogen, which is released into the atmosphere without damage can.
• This known method is extremely energy-consuming with high oxygen consumption, whereby d ammonium elemental nitrogen, which can be used as an excellent fertilizer, is converted and is therefore lost as a usable substance.
• this process produces undesirable nitrogen oxide as a by-product and contributes to air pollution.
• the present invention has for its object to provide a method for the purification of wastewater from their nitrogen and in conjunction therewith phosphate impurities and possibly heavy metals, with the aid of which other usable reaction products can be obtained at low cost and with good cleaning results.
• Another important advantage of the method of the invention over the known method is also seen therein that the addition of the reaction causing materials in *** • * ⁇ 'of the passage takes place in the waste water completely negative mold, so that not only in Waste water contained compounds are eliminated In addition, no residues of reagent material, which are also to be regarded as impurities, are found in the pure water. As extensive tests have shown, the impurities are separated far more than 9 and overall a cleaning quality that is close to drinking water quality is achieved if immediately usable Reaction products that are ideal for use in fertilizers in agriculture or for other industrial processing.
• Another advantage of the method of the invention i can also be seen in the fact that it can be used with equally good results for cleaning d waste water from both its ammonium and from their phosphate impurities and can easily be modified depending on the composition of the product Waste water allows.
• the use of the second reaction stage can be dispensed with and the reaction can be carried out exclusively with the aid of essentially monohydrogen phosphate, in particular magnesium hydrogen phosphate the pellets take place, whereas the cleaning of waste water containing both ammonium and phosphate compounds is expediently carried out in two stages, the excess ammonium compounds generally contained in the waste water being reduced to such an extent in the first stage, which is essentially formed from pellets of MgH, that the phosphate content and the ammonium content in a quantitative ratio in the wastewater is its stoichiometric proportion of the magnesium-ammonium-phosphate mole equivalent. Further (final) cleaning then takes place in the second cleaning stage on the pellets essentially formed from Mg 3 (P0 ⁇ 2) .
• the pellet suitable for use in the process according to the invention is advantageously produced in a two-stage process in such a way that phosphoric acid and metal oxide, in particular magnesium oxide with a high bulk density, are first homogenized while maintaining a reaction temperature between 25 and 30 * * * - C and then reacted and then reacted the sludge containing the orthophosphate is pelletized with the addition of further metal oxide and kaolin.
• the green pellets formed are then advantageously air-dried for a period of between 16 and 2 hours and then, for activation, for a period of from 2 to 4.5 hours, preferably about three hours, a temperature treatment at 250 ° C. to 375 ° C., preferably about 30 ° subjected to heating to the activation temperature and cooling after activation with a heating or Cooling rate of 50 ⁇ / hour takes place.
• two series-connected absorbers are advantageously provided, each of which alternately contains al fresh reaction material, pre-cleaning stage and main cleaning stage are used in such a way that the sorber acting as the working stage is filled with fresh material after saturation of the material by saturation and the other , now serving as the main cleaning stage is connected upstream as a pre-cleaning stage.
• the waste water it is expedient for the waste water to be mechanically filtered after leaving the absorber Deposition of the heavy metal hydroxide precipitated in the absorber due to the alkalization occurring there to a pH between 9 and 10.
• the pellets saturated and thus consumed by conversion to magnesium-ammonium-phosph can either be rinsed to remove mechanically adhering heavy metal residues and then used immediately as fertilizer or in a first stage by adding v diluted sodium hydroxide solution and / or diluted lime in a second step by adding Carbon dioxide can be worked up.
• a recommended refurbishment can be carried out as follows
• the pellets have a bulk porosity of over 85% by volume and a mechanical strength of about 15 kg / cm.
• the specific surface area of the pellets is approximately 50 m * * * * / g.
• the pellets obtained are used for the simultaneous removal of ammonium and phosphate ions from waste water.
• no special measures are required to adjust the A ___ monium / phosphate ratio with a very high excess of ammonium ions.
• a small amount of phosphoric acid i the absorber depending on the ammonium ion concentration i cleaned wastewater may be required to accelerate the reaction to be admitted.
• a further 14.5 kg of magnesium oxide, further as pore-forming material 2 kg of kaol and, according to the balance sheet, 7.6 kg of pelletizing water are mixed in and d pelletizing in the usual manner until pellets are formed performed a diameter of about 1 to 2.5 mm.
• the pellets obtained are used as an active substance for cleaning wastewater containing only ammonium ion and others
• the supply of phosphoric acid to the absorber for this purpose depends on the residual concentration of ammonium ion at the absorber outlet.
• the wastewater then flows through two further absorbers connected in series and filled with active pellets according to Example 1, a load of 5 to 15 m * - 5 wastewater per 1 m 3 pellets (residence time 1 to 3 minutes) being maintained.
• the second most absorber in the flow is filled with fresh pellets.
• the active pellets have a weight gain of approx. 20% after saturation. Magnesium ions cannot be detected or at least traces can be detected in pure water. //
• Pre-clarified wastewater with 3000 mg ammonium nitrogen / liter is introduced into a double absorber filled with active pellets according to Example 2 with a load of 3 to 10 m * 3 wastewater per 1 m * 3 pellets.
• D pure water flowing out of the absorber contains between 2 and 5 NH 2 N / liter and is passed in the manner described in Example 3 over a filter serving d separation of heavy metals.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Removal Of Specific Substances (AREA)
• Water Treatment By Sorption (AREA)
• Fertilizers (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Applications Claiming Priority (2)

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• 1990
  • 1990-03-21 DE DE4009082A patent/DE4009082A1/de not_active Withdrawn
• 1991
  • 1991-03-18 BR BR919105096A patent/BR9105096A/pt unknown
  • 1991-03-18 WO PCT/EP1991/000520 patent/WO1991014656A1/de not_active Application Discontinuation
  • 1991-03-18 EP EP91905788A patent/EP0473750A1/de not_active Withdrawn
  • 1991-03-21 CN CN91103336A patent/CN1055721A/zh active Pending
  • 1991-03-21 KR KR1019910004437A patent/KR910016630A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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