Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F9/00—Multistage treatment of water, waste water or sewage
• • 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
  • C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
• • 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
  • C02F1/286—Treatment of water, waste water, or sewage by sorption using natural organic sorbents or derivatives thereof
• • 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
  • 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
  • C02F1/62—Heavy metal compounds
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2101/00—Nature of the contaminant
  • C02F2101/10—Inorganic compounds
  • C02F2101/20—Heavy metals or heavy metal compounds
• • 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
  • C02F2103/10—Nature of the water, waste water, sewage or sludge to be treated from quarries or from mining activities
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2301/00—General aspects of water treatment
  • C02F2301/08—Multistage treatments, e.g. repetition of the same process step under different conditions

Definitions

• the present invention relates to a method of purification of waste water with a high content of metals, especially Ag and Cu, and a composition for use in this method.
• Metal contamination of the waste water is a common environmental problem. Heavy metals are not biodegradable and are accumulated in living organisms, causing many diseases and health disorders of such organisms.
• Table 1 Overview of methods used for the purification of waste water that contain Ag and Cu on the basis of Bartkiewicz B., "Industrial Wastewater”, PWN, Warsa 2006, Lasko C.L., Hurst M.P., Environ. Sci. Technol., 33, (1999), 3622 3626, and Smith, A.L., Swiderska-Broz M., “Water Treatment”, Oxford University Press, Wroclaw 2000.
• Chitosan is a biopolymer with high sorption properties and ability to chelate metal cations due to the presence of free amino groups in its structure [Lasko et al. (1999)]. Chitosan is non-toxic, fully biodegradable and has a high biocompatibility. Chitosan can be easily modified by chemical reactions and physical processes, which leads to new derivatives of chitosan.
• the modification processes often comprise the crosslinking reactions of chitosan [WS Wan Ngah, L. C. Teong, M.A.K.M. Hanafiah, Carbohydrate Polymers 83 (201 1 ) 1446-1456].
• Chitosan derivatives used in the recovery of copper are shown in Table 2.
• Chitosan is a compound absolutely non-toxic, so that its use, even on an industrial scale, does not cause environmental pollution.
• An important feature of this polymer is its biocompatibility. Further advantages comprise high adhesion and sorption capacity, high chemical reactivity and ability to chelate metals, because of the presence of a number of anchor groups on its surface. Due to the ability to receive multiple spatial conformation, chitosan can also capture the metal ions within its structure.
• Table 2 Overview of the chitosan modification used in the recovery of copper from a ueous solutions.
• GB 2 364 047 discloses a composition for water treatment, and also for the purification of drinking water, comprising (i) an amino group-containing polysaccharide, for example chitosan, (ii) a second, more water-soluble polymeric material having an average molecular weight of at least 100,000, preferably a polyacrylamide.
• the composition can additionally comprise an inorganic metal salt selected from the salts: ferrous sulfate, ferric chloride, aluminum chloride, aluminum sulfate, manganese sulfate, manganese chloride, copper sulfate, copper chloride, or combinations thereof.
• the composition may further comprise a disinfectant.
• Polyacrylamide polymer is used as additional in the described composition. It is known that acrylamide is classified as carcinogenic material (material mutagenic category II). Thus, a use of polyacrylamide for purification of drinking water is associated with a risk of the water contamination with the monomer leading to the health hazard.
• JP 9290231 describes a method for prevention of the leaching of heavy metals from the treated material.
• metal was quenched with mixture of water, chitosan, and phosphoric acid and all the ingredients were kneaded with dust.
• this description comprises no mention of any introduction of such composition into the water in order to remove the metal from water.
• purifying water to a safe level for living organisms.
• a process for purifying waste water according to the invention responds for such a need, thanks to the combination of chitosan with soluble inorganic salts in suitable proportions, which allows treatment of waste water with high content of copper and silver to the levels safe for living organisms.
• a method of water purification treatment involves a two-step process.
• a mixture of commercially available water-soluble salts especially phosphate(V) and sulfate(VI), and chitosan.
• Chitosan is practically insoluble in water, binding silver and copper ions, then in effect, its specific weight increases and it settles on the bottom of the container in the form of an insoluble metal complex.
• Silver (I) and copper (II) react leading to precipitation in result of forming a poorly water-soluble inorganic salts (Ag 2 S044, Ag 3 P0 4
• chitosan mixture with salts provides adequate viscosity and specific weight of the resulting precipitate. This precipitate can be easily filtered out.
• the resulting aqueous solution is colorless, clear, and is characterized by reduced acidity (pH ⁇ 6).
• the second step of this process provides ultimate cleaning of waste water to the level of metal content below 1 ppm. For this purpose an additional, suitable amount of the chitosan is used. After completion of the second step of the reaction the solution obtained by metal removal can be decanted from the precipitate and filtered. A clear, colorless and odorless filtrate is obtained with the metal content below 1 ppm.
• the invention relates to a process for purifying waste water with a high content of metals, comprising two steps.
• the mixture comprising a combination of at least two ions selected from the group consisting of: S0 4 2" , P0 4 3 ⁇ , ⁇ , Cl ⁇ , and chitosan are added to the container filled with waste water, while maintaining the oxygen availability and mixing.
• Precipitate is filtered off, and then in the second step, chitosan is again added to the filtrate preferably chitosan is added in an amount of 10 g/1 to 150 g/1.
• ions selected from SO PO4 3" , ⁇ , CI " are added in the form of well water- soluble salts, comprising acid salts.
• the ions selected from S0 4 2' , P0 4 3" , ⁇ , cr are added as ammonium salts, salts or acid salts of alkali metals, especially sodium or potassium.
• a combination of the salts SO 4 2" , PO 4 3" selected from the group consisting of Na 2 SC> 4 , NaHSC> 4 and Na 2 HP0 4 , NaH 2 P0 4 , Na 3 P0 4 is added .
• the invention is particularly suitable for the purification of waste water with a high content of copper and/or silver.
• the excess of SO4 2" ions in relation to Ag + ions is used. More preferably the excess of SO4 2" ions in relation to Ag + ions in ratio at least 1.1 : 1 molar equivalents, preferably in a ratio of 1.2: 1 molar equivalents is used.
• excess of P ⁇ 3 ⁇ 4 3+ ions in relation to Cu 2+ ions is preferably used. More preferably the excess of P0 4 3+ ions in relation to Cu 2+ ions in ratio at least 1 ,1 : 1 molar equivalents, preferably in a ratio of 1 ,8:1 molar equivalents is used.
• chitosan is added in amount corresponding to 40%-90%, more preferably 50-80%, of the total mass weight of both salts used.
• the present invention also provides a composition for the treatment of waste water with a high content of metals, comprising a mixture of well-soluble salts of acid radical SO4 2" , P0 4 3' , ⁇ , or CP, and chitosan, wherein the salts are in an excess of at least about 1.1 : 1 molar equivalents of the purified metal and chitosan is in an amount equivalent to 40%-90%, preferably 50-80%, of the total weight of each salt used.
• the composition contains preferably ammonium salts or acid salts of alkali metals, especially sodium salts, sodium acid salts, potassium salts or potassium acid salts.
• the composition comprises a combination of salts having acid radical SO4 2" , PO4 3" , wherein salts are selected from the group consisting of Na S0 4 , NaHS0 4 i Na 2 HP04, NaH 2 P0 4 , Na 3 P0 4 .
• Figure 1 shows a UV-VIS spectra, taken in order to determine the concentration of copper ions in the obtained aqueous solution
• Figure 2 is a graph illustrating changes in the concentration of metals in the aqueous solution during the application of the procedure according to the invention
• Figure 3 is a graph showing the kinetics of removing silver(I) and copper(II) ions in reaction with a mixture of chitosan and soluble inorganic salts of phosphoric(V) and sulfuric(VI) acids;
• Figure 4 is a graph showing the kinetics of removing silver(I) and copper(II) ions by chitosan in the second purification step.
• Table 3 Results of the determination of copper ions using UV-VIS spectroscopy, and copper and silver ions using ICP MS in the resulting aqueous solutions.
• the sample under assay Concentration of copper The concentration of ions in ions in solution [nig/1] as solution [mg/1] as measured determined by UV-VIS by ICP MS.
• a process for purification of wastewater with a high content of metals was developed and optimized at a laboratory scale.
• a sample of waste water containing 35 g/1 of silver ions and 10 g/1 of copper ions and pH 3 was subjected to two steps of the purification process.
• mixture of salts 0.28 g Na 2 SC»4, 0.16 g Na 3 P0 4 and 0.22 g of chitosan was added to 5 ml of waste water.
• Significant part of the copper and silver ions in the solution has been precipitated on the bottom of the vessel in the form of a water-insoluble precipitate.
• a clear, colorless filtrate was obtained having reduced acidity (pH ⁇ 6).
• Table 4 Results of ICP MS analysis of the metal content in the samples after the I and II purification step.
• the UV-VIS analysis showed no presence of copper in the obtained solution (copper concentration of ⁇ 7.94 mg kg).
• ICP MS analysis showed the presence of metals at the level of 32 mg kg of silver and 5.34 mg/kg for copper.
• the addition at the second step 50 mg of chitosan, and then centrifuging the precipitate, enables to obtain the content of silver in the solution at the level of 4.00 ⁇ 0.01 mg/kg, and copper - 1.34 ⁇ 0.2 mg/kg.
• Increasing the amount of chitosan in the second step allows obtaining the levels for both metals of less than 1 mg/kg (1 ppm).
• a sample of 5 ml aqueous solution containing 35 g/1 of silver ions and 8 g/1 of copper ions was prepared.
• a mixture of 0.28 g Na 2 S04, 0.16 g Na 2 HP04 and 0.22 g of chitosan was added to the sample.
• the sample was mixed vigorously. Part of silver and copper ions contained in the solution precipitated on the bottom of the vessel in the form of a water-insoluble precipitate.
• the sample was centrifuged, and sample of a small portion of the supernatant solution was collected for the analysis. The remaining solution and precipitate was allowed to stir open to the air. After 24 hours the precipitate was collected by centrifugation and another small portion of the supernatant solution was taken.
• the collected samples were submitted for ICP MS analysis of content of silver and copper ions in solution. In this manner the kinetics of metal ions (Ag, Cu) removal in result of addition of the test mixture according to the invention was determined.
• 0.28 g Na 2 S0 4 , 0.16 g Na 2 HP0 4 (1.2 eq S0 4 2" relative to Ag + ions and 1.8 eq P0 4 3" with respect to Cu z+ ions) and 0.088 g of chitosan (20% by weight of the sum of both the added salts) were added To the second sample.
• 0.28 g Na 2 S0 4 , 0.16 g Na 2 HP0 4 (1 .2 eq S0 4 2" relative to Ag + ions and PO4 3" 1.8 eq with respect to Cu 2+ ions 0.28 g Na 2 S0 4 , 0.16 g Na 2 HP0 4 (1 .2 eq S0 4 2" relative to Ag + ions and PO4 3" 1.8 eq with

Landscapes

• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Removal Of Specific Substances (AREA)
• Water Treatment By Sorption (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49263418

Family Applications (1)

Country Status (3)

Families Citing this family (3)

Family Cites Families (2)

• 2012
  • 2012-08-03 PL PL40023612A patent/PL233402B1/pl unknown
• 2013
  • 2013-08-02 WO PCT/PL2013/000100 patent/WO2014021726A1/en not_active Ceased
  • 2013-08-02 EP EP13770717.0A patent/EP2917153A1/de not_active Withdrawn

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events