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
  • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
  • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
• • 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
  • C02F1/545—Silicon compounds
• • 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
  • C02F1/56—Macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/02—Aerobic processes
  • C02F3/10—Packings; Fillings; Grids
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F3/00—Biological treatment of water, waste water, or sewage
  • C02F3/02—Aerobic processes
  • C02F3/12—Activated sludge 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
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W10/00—Technologies for wastewater treatment
  • Y02W10/10—Biological treatment of water, waste water, or sewage
• • 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
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W10/00—Technologies for wastewater treatment
  • Y02W10/40—Valorisation of by-products of wastewater, sewage or sludge processing

Definitions

• the invention relates to the enhancing of the efficiency of biochemical and/or physico-chemical purification technologies used to remove dissolved and insoluble organic and/or inorganic contaminating materials from waters and to decrease the time and reagent demand of treatment.
• zeolites - or zeolites activated by treatment with reagent or mixtures thereof are added to the sewage to be purified in order to enhance efficiency. It was in Hungary where natural zeolites were first used for sewage purification by activated sludge.
• Heinzel uses a preliminary microbiological and/or enzymatic and/or substrate addition [Heinzel, K., IPUS GmbH. (2000): Zeolite based bioactive product; the corresponding Hungarian patent application number is P0000604].
• the method according to the referred patent application slightly decreases the time re- quirement of the process. This can be explained by the fact that although the bacteria (Nitrosonomas, Nitrobacters, etc.) brought into contact with the zeolite in an aqueous suspension or an aerosol provide a high bacterium concentration on the external zeolite surface, between the bacteria and the zeolite particles stable bond is not formed.
• a significant part of the bacteria is re- moved from the zeolite surface due to the frictions occurring in the biological reactor.
• the accelerating effect can be essentially explained by the excess microorganisms added into the reactor though they have to be adapted to the given sewage.
• the enzyme content of the zeolite with enzyme additives functions as a substrate under the conditions of sewage purification by activated sludge, and, similarly to the zeolites treated with substrates, it can mainly exert its favorable effects in systems with insufficient nutrients.
• the accelerating effect is not significant in this case either, which can be explained by the fact that the limiting factor of the favorable effects of the zeolite addition is rather the adsorption time of the bacteria on the zeolite surface than the time required for the zeolite-substrate adsorption. It follows from the foregoing that the object of the process according to the invention is to find an appropriate method for treating the zeolite-containing materials to enable the bacteria to settle on the zeolite surface quickly and to induce the prompt appearance of the favorable effects of the zeolite and the development of additional favorable effects.
• the process according to the invention is based on the following discoveries:
• the surface charge of the bacteria is also negative in the aqueous phase. It is well known that particles of similar charge repulse each other, therefore, it can be eas- ily seen that the adsorption of the bacteria on the zeolite surface is hindered.
• the fact that the zeolite-bacterium bond is formed can be attributed to the extracellular polymers (ECP) produced by the bacteria since the ECP molecules support positive charges and can bridge the bacteria and the zeolite surface.
• ECP extracellular polymers
• CAP positively charged cation-active polymers
• a CAP-modified zeolite When a CAP-modified zeolite is used a large number of zeolite-bacterium floes are formed in the activated sludge tank due to positively charged bacteria which are bound to the CAP covered zeolite particles, therefore, the zeolite can exert its favorable effects in a few minutes.
• the process according to the invention is based on the idea that zeolites with CAP-treated surfaces have to be added to the water to be purified in order to accelerate the immobilization of the bacteria on the zeolite surface and to increase the bacterium concentration on the surface. This means that, according to the invention, the slow and uncertain biopolymer production of the bacteria is not allowed to control the fixation of bacteria on zeolite.
• the zeolite-CAP bond can be formed only on the external surface of the zeolite crystal since large organic molecules cannot be accommodated in the (inner) pores of the zeolite (the pore diameters are between 6 and 10 A). It can generally be stated that the external surface charge of the zeolites is about 8 to 10% of the total charge or the total ion- exchange capacity (IEC).
• Low molecular weight CAP compounds comprise less monomer units and thus lower number of positive charges, therefore, they can be bound weaker to the zeolite particles and are capable to immobilize lower number of bacteria than high molecular weight CAP.
• high molecular weight CAP compounds it can be difficult to form stable zeolite-CAP bonds with mechanical resistance due to the significant molecular length. It follows that the modification has a certain preferable molecular weight range which is between 5,000 and 250,000 according to the experience of the applicants.
• the CAP can be used preferably in a 5 to 10% excess of the theoretical value.
• the favorable effects occur also at a lower CAP amount but they do not reach their maximum.
• Increasing the CAP amount the positive effects are not decreased, but the CAP excess is removed from the zeolite which may unnecessarily increase the water treatment costs.
• the CAP excess can be removed by washing the modified zeolite with water.
• the zeolite In order to bind chemically the CAP molecules to the zeolite particles in the case of natural zeolites which contain generally Na, K, Ca or Mg in cationic sites, i.e., zeolites in Na-, K-, Mg-, Ca-forms, the zeolite is first to be converted to H- or NH -form or the pH of the aqueous solution of the CAP used for modification is to be decreased below 5. Note that the natural free and bound water content of the zeolites can also be considered as water.
• the pulverized rhyolite tuff is suspended in a two- to threefold amount of a HC1 or ammonium salt solution of about 0.1 normal concentration.
• the treated zeolite is agitated for one to two hours.
• the suspension is settled and decanted.
• the dense suspension remaining after decantation is washed with tap-water until the pH of the rinsing water reaches 6 or it becomes ammonium-free.
• the main feature of the process according to the invention is that, in order to enhance the efficiency and to decrease the time and reagent requirements of biochemical and/or physico-chemical purification technologies used to remove the dissolved and insoluble, organic or inorganic contaminating materials or combinations thereof from waters, one or more artificial or natural materials containing at least 1 weight% crystalline alumino-hydrosilicates having a three-dimensional crystal lattice comprising a pore structure of molecular size, preferably one or more types of rock granules containing clinoptilolite, mordenite and/or other zeolites are added to the water to be treated or to the activated sludge, and macromolecules comprising a large number of positively charged groups, preferably cation-active polymers are bonded previously to the said materials by physical-chemical bonds so that free positively charged groups still remain on the bonded macromolecules.
• Crystalline alkaline or alkaline earth alumino-hydrosilicates having a three- dimensional crystal lattice or mixtures thereof having a grain size below 200 ⁇ m can be used, for example, as rock granules.
• organic macromolecules with quaternary nitrogen atoms, having a molecular weight above 5,000, are bonded as cation-active polymers to the said rock granules before adding them to the water to be purified.
• the bond between the said materials is formed by mixing the rock granules, converted in a hydrogen or ammonium form by an acidic or ammonium salt treatment, with the aqueous solution of a cation-active polymer.
• the bond between the materials is formed by mixing the rock granules with the aqueous solution of the cation-active polymer having a pH below 5.
• the additive produced as described above is mixed, preferably in a concentration of 10 to 200 mg/L, into the water to be purified by a biochemical and/or physico-chemical method, or it is added to the activated sludge decomposing the organic substances, preferably in an amount of 1 to 20 weight%.
• the preferable embodiments of the process according to the invention are illustrated with the follow- ing examples to facilitate understanding but without limiting the invention. Unless otherwise indicated, the percentage values mean weight%.
• 100 kg rhyolite tuff originating from the area of Ratka/Hungary and contain- ing 50 to 55% zeolite is pulverized.
• 200 mL of the 50% aqueous solution of a poly- acrylamine type /poly-2-(hydroxypropyl)-N,N-dimethyl ammonium chloride/ cation- active polymer having a molecular weight of 50,000 is mixed to 18 to 19 liters tap- water and then the pH of the solution is set to 2.2 by the addition of hydrochloric acid. After mixing it for half an hour, when the cation-active polymer molecules are already bound to the tuff particles, the suspension is used to purify sewage.
• the suspension is fed into the sewage to be purified continuously or in batch mode.
• the appropriate suspension/sewage ratio is determined by laboratory experiments. During the experiments, the sewage to be purified is subjected to biological decomposition investigations, in continuous or batch mode, and the suspension/sewage ratio is varied from measurement to measurement. The suspension/sewage ratio leading to the best water quality according to the laboratory experiments is used during the sewage treatment on a large scale. The suspension/sewage ratio is expressed then in gzeoiite/gdry activated sludge units. The preferable gzeoiite dr activated sl dge ratio can be expected to fall between 2 and 15%.
• zeolite 100 kg rhyolite tuff originating from the area of Ratka/Hungary and containing 50 to 55%) zeolite is pulverized. 10 kg of the grain fraction between 30 and 50 ⁇ m of the ground tuff is suspended in 40 liters 0,5 normal HC1 solution. The suspension is mixed for 3 to 4 hours at ambient temperature and the aqueous phase is decanted from the tuff after 10 minutes settling. The tuff is filtered and thoroughly washed with distilled water until the pH of the filtrate increases to 6.
• the filtered, washed tuff is added to 8 to 19 liters tap-water in which the aqueous solution of 1 liter 50%> polyacrylamine /poly-2-(hydroxypropyl)-N,N-dimethyl ammonium chloride/ having a molecular weight of 50,000 has been mixed previously.
• the suspension is mixed for 2 hours and after settling it is decanted and filtered.
• the filtered, surface-treated tuff is washed with tap-water until the total organic carbon content of the filtrate decreases below 2 mg/L.
• the modified tuff freed from the CAP excess is used for water purification according to Example 1.
• 100 kg rhyolite tuff originating from the area of Ratka/Hungary and containing 50 to 55% zeolite is pulverized. 10 kg of the grain fraction between 30 and 50 ⁇ m of the ground tuff is suspended in 40 liters 0,5 normal NH 4 C1 solution. The suspension is mixed for 3 to 4 hours at ambient temperature and the aqueous phase is decanted from the tuff after 10 minutes settling. The tuff is filtered and thoroughly washed with distilled water until the ammonium content of the filtrate decreases below 0.1 mg/L.
• the filtered, washed tuff is added to 8 to 19 liters tap-water in which the aqueous solution of 1 liter 50% polyacrylamine /poly-2-(hydroxypropyl)- N,N-dimethyl ammonium chloride/ having a molecular weight of 50,000 has been mixed previously.
• the suspension is mixed for 2 hours and after settling it is decanted and filtered.
• the filtered, surface-treated tuff is washed with tap-water until the total organic carbon content of the filtrate decreases below 2 mg/L.
• the modi- fied tuff freed from the CAP excess is used for water purification according to Example 1.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Organic Chemistry (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Engineering & Computer Science (AREA)
• Hydrology & Water Resources (AREA)
• Inorganic Chemistry (AREA)
• Biodiversity & Conservation Biology (AREA)
• Microbiology (AREA)
• Treatment Of Sludge (AREA)
• Water Treatment By Sorption (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=89978804

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (4)

• 2000
  • 2000-11-28 HU HU0004740A patent/HU223798B1/hu not_active IP Right Cessation
• 2001
  • 2001-11-27 WO PCT/HU2001/000122 patent/WO2002044094A1/en not_active Application Discontinuation
  • 2001-11-27 AU AU2002220933A patent/AU2002220933A1/en not_active Abandoned

Patent Citations (4)

Non-Patent Citations (5)

Also Published As

Similar Documents

Legal Events