CA2282432C - Biosorption agents for metal ions and method for the production thereof - Google Patents
Biosorption agents for metal ions and method for the production thereof Download PDFInfo
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- CA2282432C CA2282432C CA 2282432 CA2282432A CA2282432C CA 2282432 C CA2282432 C CA 2282432C CA 2282432 CA2282432 CA 2282432 CA 2282432 A CA2282432 A CA 2282432A CA 2282432 C CA2282432 C CA 2282432C
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- 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
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/22—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising organic material
- B01J20/24—Naturally occurring macromolecular compounds, e.g. humic acids or their derivatives
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- 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
- Y02W30/00—Technologies for solid waste management
- Y02W30/40—Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse
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Abstract
The invention relates to biosorption agents for metal ions with a biological - nature base. Said agents consist of particles which are formed by grinding cereal grains and are insoluble in an aqueous system and/or inorganic solvents, which are modified in such a wa y that the nitrogen content ranges from 0.1 to 10%, the phosphor content ranges from 0.1 to 20% and the sulfur content ranges from 0.1 to 8%.
Description
Description The invention relates to new biosorbents for binding metal ions, produced from residue of the food industry, and to the production process and use of such biosorbents.
The biosorption of heavy-metal ions to materials of bio-natural origin - which is also referred to as biosorbent - has created considerable, practical interest due to the easy and inexpensive accessibility, simple modifiability, partially high binding capacity to metal ions and their biodegradability. This biomass is obtained, e.g., as a by-product or as residue or waste material in large-scale fermentation, in the form of metal-binding algae in oceans, as well as in agriculture and in the forest, paper and food industry. The use of such biomass, which is available in large quantities and at low cost as metal-immobilizing biosorbents is an appealing alternative for removing heavy metals from the environment instead of the conventional ion-exchanger chromatography with synthetic polymers or inorganic materials.
Biomasses obtained in industrial processes of large-scale fermentations show in some cases a very high metal-binding capacity which, e.g., in some fungi can amount to 25%
of their biomass, and in certain brown algae of marine origin even up to 30%
of their biomass (Biotechnol. Prog. 1995, 11, 235-250). Such high binding rates are generally not the rule. Due to the fact that the microbial biomass obtained by industrial means, and the biomasses obtained by harvesting the algae of the oceans, are a cheap base material for the production of heavy- metal ion binding biosorbents, more effective biosorbents are produced by chemically modifying such biomass.
Carbo-hydrate-containing raw materials, as well as by-products, residue or waste materials of the forest and paper industry, are likewise taken into consideration as potential biosorbents for metal ions. Even more than bioabsorbers.of microbial origin, such carbohydrate-containing biomasses have first of all to be chemically modified in order to result in effective biosorbents. The modification reactions are carried out in such a way as to increase the already naturally existing, however very low ion exchange capacity of these biosorbents. Such high binding capacity is primarily achieved by introducing phosphate groups into the carbohydrate-containing biomasses derived from the forest and paper industry. Through phosphorylation with variable phospholating agents phosphate groups are convalent bonded, e.g., in cellulose (FA-A-2206977) lignocellulose (WO
93/11196) wood residue (JP90-122269), saw dust (JP87-267 663), paper pulp (JP86-234-543) and starch (JP92-308 078). However, such biosorbents and the production processes thereof have not yet been technically applied.
In contrast to the biosorbents of marine and microbial origin and those derived from the forest and paper industry, the possibilities of biosorption of metal ions to residue and waste materials from agriculture and the food industry have not been examined to any extent up to now, and the chemical modification of such regenerative raw materials for the development of metal-binding bioabsorbers and their technical use for metal-ion absorption has not been considered at all.
Starting out from this premise, it is the object of the this invention to suggest new biosorbents for metal ions and a process to produce same on a bionatural basis.
The problem is solved with respect to the biosorbents by biosorbents on a biological-natural basis derived from grain grinding residue, and in regard to the production process of biosorbents by a method in which the residue is chemically treated to enhance its metal ion binding capacity. In a preferred embodiment, the bisorbent in accordance with the invention consist of residue from grain grinding in an aqueous system and/or particles insoluble in inorganic solvents, which have been modified through treatment with a combination of the general formula I
The biosorption of heavy-metal ions to materials of bio-natural origin - which is also referred to as biosorbent - has created considerable, practical interest due to the easy and inexpensive accessibility, simple modifiability, partially high binding capacity to metal ions and their biodegradability. This biomass is obtained, e.g., as a by-product or as residue or waste material in large-scale fermentation, in the form of metal-binding algae in oceans, as well as in agriculture and in the forest, paper and food industry. The use of such biomass, which is available in large quantities and at low cost as metal-immobilizing biosorbents is an appealing alternative for removing heavy metals from the environment instead of the conventional ion-exchanger chromatography with synthetic polymers or inorganic materials.
Biomasses obtained in industrial processes of large-scale fermentations show in some cases a very high metal-binding capacity which, e.g., in some fungi can amount to 25%
of their biomass, and in certain brown algae of marine origin even up to 30%
of their biomass (Biotechnol. Prog. 1995, 11, 235-250). Such high binding rates are generally not the rule. Due to the fact that the microbial biomass obtained by industrial means, and the biomasses obtained by harvesting the algae of the oceans, are a cheap base material for the production of heavy- metal ion binding biosorbents, more effective biosorbents are produced by chemically modifying such biomass.
Carbo-hydrate-containing raw materials, as well as by-products, residue or waste materials of the forest and paper industry, are likewise taken into consideration as potential biosorbents for metal ions. Even more than bioabsorbers.of microbial origin, such carbohydrate-containing biomasses have first of all to be chemically modified in order to result in effective biosorbents. The modification reactions are carried out in such a way as to increase the already naturally existing, however very low ion exchange capacity of these biosorbents. Such high binding capacity is primarily achieved by introducing phosphate groups into the carbohydrate-containing biomasses derived from the forest and paper industry. Through phosphorylation with variable phospholating agents phosphate groups are convalent bonded, e.g., in cellulose (FA-A-2206977) lignocellulose (WO
93/11196) wood residue (JP90-122269), saw dust (JP87-267 663), paper pulp (JP86-234-543) and starch (JP92-308 078). However, such biosorbents and the production processes thereof have not yet been technically applied.
In contrast to the biosorbents of marine and microbial origin and those derived from the forest and paper industry, the possibilities of biosorption of metal ions to residue and waste materials from agriculture and the food industry have not been examined to any extent up to now, and the chemical modification of such regenerative raw materials for the development of metal-binding bioabsorbers and their technical use for metal-ion absorption has not been considered at all.
Starting out from this premise, it is the object of the this invention to suggest new biosorbents for metal ions and a process to produce same on a bionatural basis.
The problem is solved with respect to the biosorbents by biosorbents on a biological-natural basis derived from grain grinding residue, and in regard to the production process of biosorbents by a method in which the residue is chemically treated to enhance its metal ion binding capacity. In a preferred embodiment, the bisorbent in accordance with the invention consist of residue from grain grinding in an aqueous system and/or particles insoluble in inorganic solvents, which have been modified through treatment with a combination of the general formula I
2 a, n c wherein X 0, S or NH
R1 = NH2, NH-NH2, and R2 = NH2, NH-NH2, NH-CO-NH2, N(HC3)-CH2-COOH, NH-(CH2)3 -CH(NHZ)-COOH, and acids, such that the nitrogen content is in the range of 0.1 to 20%, the phosphor content in the range of 0.1 to 20%, and the sulphur content in the range of 0.1 to 8%.
In a preferred embodiment of the method of production of the biosorbents, the residue from grain grinding is treated at 50 to 200 C over a time span of 1 to 20 hours with a combination of the compound of general formula I, as defined above, and an acid, and subsequently separated.
Residue from grain grinding forms the basis of biosrobents, according to the invention. Such residue, which is obtained by extracting the flour from the grain, accumulates in large quantities in flour mills during the flour production process. Due to its high carbohydrate content, as well as its nitrogen content of approximately 3%, its 2a phosphorus content of less than 2% and its sulphur content of less than 0.2%, the residue has only been used as animal feed up to now and not as a base material for useable products, e.g., for obtaining biosorbents for metal-ion binding.
Residue from the grinding of all kinds of grain, such as wheat, barley, rye, triticale, millet, as well as corn and rice can be used to produce the biosorbents, according to the invention.
Residue of grain grinding itself has - even though it is very low - a metal-binding capacity of less than 0.2 milli-equivalents per gram of dry material. In order to be able to fully utilize the advantages of the residue of grain grinding, it is necessary to modify it, if possible, by simple and inexpensive methods to achieve greater binding capacities to metal ions.
The biosorbents for binding metal ions are characterized by consisting preferably of spherical particles of residue of grain grinding - which are insoluble in aqueous systems and/or organic solvents - i.e. residue of grains from which the flour content has been extracted and which are composed of carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus and in which the residue of grain-grinding is modified in such a way that the nitrogen content of the biosorbents is 0 to 20% (preferably 4 to 15%), the phosphorus content is 0 to 20% (preferably 6 to 15%) and the sulphur content is 0 to 8%.
According to the invention, the ground-grain residue is modified preferably by reacting it with carbonic or thiocarbonic acid derivatives, or mixtures of both, of general formula (1), X= C
in organic solvents or watery solutions, or a mixture of both at temperatures of 50 C up to 200 C in the presence of an acid, or if necessary, also without acid.
R1 = NH2, NH-NH2, and R2 = NH2, NH-NH2, NH-CO-NH2, N(HC3)-CH2-COOH, NH-(CH2)3 -CH(NHZ)-COOH, and acids, such that the nitrogen content is in the range of 0.1 to 20%, the phosphor content in the range of 0.1 to 20%, and the sulphur content in the range of 0.1 to 8%.
In a preferred embodiment of the method of production of the biosorbents, the residue from grain grinding is treated at 50 to 200 C over a time span of 1 to 20 hours with a combination of the compound of general formula I, as defined above, and an acid, and subsequently separated.
Residue from grain grinding forms the basis of biosrobents, according to the invention. Such residue, which is obtained by extracting the flour from the grain, accumulates in large quantities in flour mills during the flour production process. Due to its high carbohydrate content, as well as its nitrogen content of approximately 3%, its 2a phosphorus content of less than 2% and its sulphur content of less than 0.2%, the residue has only been used as animal feed up to now and not as a base material for useable products, e.g., for obtaining biosorbents for metal-ion binding.
Residue from the grinding of all kinds of grain, such as wheat, barley, rye, triticale, millet, as well as corn and rice can be used to produce the biosorbents, according to the invention.
Residue of grain grinding itself has - even though it is very low - a metal-binding capacity of less than 0.2 milli-equivalents per gram of dry material. In order to be able to fully utilize the advantages of the residue of grain grinding, it is necessary to modify it, if possible, by simple and inexpensive methods to achieve greater binding capacities to metal ions.
The biosorbents for binding metal ions are characterized by consisting preferably of spherical particles of residue of grain grinding - which are insoluble in aqueous systems and/or organic solvents - i.e. residue of grains from which the flour content has been extracted and which are composed of carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus and in which the residue of grain-grinding is modified in such a way that the nitrogen content of the biosorbents is 0 to 20% (preferably 4 to 15%), the phosphorus content is 0 to 20% (preferably 6 to 15%) and the sulphur content is 0 to 8%.
According to the invention, the ground-grain residue is modified preferably by reacting it with carbonic or thiocarbonic acid derivatives, or mixtures of both, of general formula (1), X= C
in organic solvents or watery solutions, or a mixture of both at temperatures of 50 C up to 200 C in the presence of an acid, or if necessary, also without acid.
3 In another exemplified production process of biosorbents, according to the invention, 0.1 part by weight of sulphuric acid and 2 parts by weight of an addition compound of phosphoric acid and carbonic and/or thiocarbonic acid derivative, or a mixture of both, and possible also 0.5 up to 2 parts by weight of sodium triphosphate are dissolved or suspended in 20 parts by weight of distilled water. 1 part by weight of residue of grain grinding is added to this mixture and worked to a well mixed, dough-like mass which is processed as described above.
As a result of such production processes, biosorbents with a very high metal-ion binding capacity are obtained. Their typical exchange capacities range from 3 to 6 milli-equivalents per gram of dry biosorbent. By varying the concentration of the reaction components, solvents, reaction temperatures and the reaction time, it is also possible, if requested, to synthesize biosorbents with lower exchange capacities than those indicated above.
The reaction mixtures are reprocessed in such a way that the solvent is separated from the suspensions, and the remaining solid matter is washed with water, diluted hydrochloric acid and distilled water, and then dried at 100 C. The solid matter of the former dispersion is to be suspended in water and likewise washed with water, diluted hydrochloric acid and distilled water and subsequently dried.
Biosorbents based on residue of grain grinding can be used very advantageously, according to the invention, to absorb metal ions, particularly, however, the ions of heavy metals and radionuclides. They have a substantially higher binding capacity of those ions than the unmodified residue of grain grinding. The absorption of metal ions can be accomplished by way of the batch procedure as well as the column procedure. In the batch procedure the biosorbents are suspended in the metalliferrous solutions, which should have a pH-value of 4 to 8, preferably 4.5 to 7Ø The solution is stirred for 0.3 minutes up to 8 hours, preferably 0.5 to 3 hours. Thus, the metal ions become bound to the bioabsorber. In the column procedure, the bioabsorbers are filled into a chromatographic column. The content of the column is brought -to a pH-value as
As a result of such production processes, biosorbents with a very high metal-ion binding capacity are obtained. Their typical exchange capacities range from 3 to 6 milli-equivalents per gram of dry biosorbent. By varying the concentration of the reaction components, solvents, reaction temperatures and the reaction time, it is also possible, if requested, to synthesize biosorbents with lower exchange capacities than those indicated above.
The reaction mixtures are reprocessed in such a way that the solvent is separated from the suspensions, and the remaining solid matter is washed with water, diluted hydrochloric acid and distilled water, and then dried at 100 C. The solid matter of the former dispersion is to be suspended in water and likewise washed with water, diluted hydrochloric acid and distilled water and subsequently dried.
Biosorbents based on residue of grain grinding can be used very advantageously, according to the invention, to absorb metal ions, particularly, however, the ions of heavy metals and radionuclides. They have a substantially higher binding capacity of those ions than the unmodified residue of grain grinding. The absorption of metal ions can be accomplished by way of the batch procedure as well as the column procedure. In the batch procedure the biosorbents are suspended in the metalliferrous solutions, which should have a pH-value of 4 to 8, preferably 4.5 to 7Ø The solution is stirred for 0.3 minutes up to 8 hours, preferably 0.5 to 3 hours. Thus, the metal ions become bound to the bioabsorber. In the column procedure, the bioabsorbers are filled into a chromatographic column. The content of the column is brought -to a pH-value as
4 described in the batch procedure, and the metalliferous solution of the same pH-value is passed continuously through the column. In doing so, the metal ions likewise become bound to the biosorbents. According to the dimensioning of the column content and the metalliferous solutions of heavy metals, water purified in compliance with statutory regulations leaves the column. The metalliferous bioabsorbers can subsequently be regenerated with diluted acids and re-used for metal-ion binding purposes.
A special advantage of the biosorbents, according to the invention, is that the residue and waste material obtained from the food industry can be used as biosorbents.
Particularly the residue of grain-grinding which accumulates in flour mills as remainder, by which is meant the residue of the grain from which the flour has been extracted, is a potential material. Such residue has characteristics which make the latter especially suitable for the development of biosorbents. Said residue is insoluble in watery or organic solvents, and its change in volume is insignificant when subjected to a change in the pH-value or in ion strength. Furthermore, such residue is hydrophillic and can therefore very well tolerate being wetted with water. Thus, it is suited for work in aqueous media without restrictions. Due to the physical properties said residue is most suitable for the continuous application of metal-ion absorption in columns for the flow chromatography despite its bio-organic nature.
The biosorbents obtained according to the invented process, show a substantially improved binding capacity to metal ions, particularly, however, to heavy-metal ions and ions of radionuclides than the unmodified residue of grain grinding or the biosorbents of marine or microbial origin. Due to standardized production processes, reproducible binding rates for metal ions are available with respect to such biosorbents, which, however cannot be guaranteed for algae and microorganisms. In the latter case the metal-binding rate depends mainly on growth conditions. The biosorbents, according to the invention, bind univalent metal ions as well as metal ions of a higher valence and surpass in their binding capacity to heavy-metal ions and radionuclides the conventional absorbers of organic or inorganic origin.
In the compounds of the general formula (1) the following mean:
X = O,S, NH;
R1 = NH2, NH-NH2; and R2 = NH2, NH-NH2, NH-CO-NH2 N(CH3)-CH2-COOH.
N H-C Hz)3-C H( N HZ)-COO H
The invention relates, in addition, to a production process for biosorbents for metal ions on a bionatural basis in which the residue of grain grinding is treated with the above-described compound of the general formula (1) and subsequently separated. The residue of grain grinding is preferably processed in the presence of an acid. The duration of the treatment with the compound of the general formula (1) can range from 1 to 20 hours at a temperature of 50 to 200 C.
The modification is achieved in an organic solvent, a watery solution or a mixture of both.
Aprotic solvents with a higher boiling point, preferably dimethylformamide or dimethyl sulphoxide, are used as solvents. As watery solutions, it is preferable to use either distilled water or phosphate buffer with a pH-value of 5.0 to 8.0 and an ion strength ranging from 0.01 to 1 Mol/L, which may contain, in addition, polyphosphates and/or the salts thereof, or mixtures.of the above-mentioned organic solvents and watery solutions.
Sulphuric acid and/or phosphoric acid and/or polyphosphoric acid are used as acids.
A preferred production process is characterized by suspending the residue of grain grinding either in a solvent which contains a carbonic acid or thiocarbonic acid derivative or a mixture of both and possibly a dissolved acid. The suspensions are heated to 100 C
up to 200 C, preferably to 140 C up to 160 C whilst stirring. The stirring continues at the selected reaction temperature for 0.5 to 8 hours or, however, the suspension is processed into a disperse dough-like system by using the compounds of the general formula (1), which are dissolved in the solvents, and possibly an acid. Such dough is subjected for 2 to 20 hours, preferably 4 to 15 hours to a temperature of 60 C
to 100 C, preferably 700 to 80 C. The subsequent modification of the residue of grain grinding at temperatures of 120 C to 200 C, preferably 140 to 160 C is completed within 1 to 10 hours, preferably 2 to 5 hours. In both cases the duration of the heating depends on the selected temperature. The incubation can be accomplished statically or in a mobile manner by means of appropriate devices.
The weight ratios of the components to be used for the reactions can be chosen freely to a large extent. The weight ratio of the acid to the carbonic acid or thiocarbonic acid derivative, or a mixture of both is set to 0.1:2 up to 0.1:20, preferably 1:2 up to 1:6, and possibly by adding 0.1 up to 5 parts by weight, preferably 0.5 up to 2 parts by weight of a polyphosphate or its alkali salt. It is advantageous to produce a concentrated solution from the solvent used and the carbonic acid and/or thiocarbonic acid derivative, or a mixture of both.
In an exemplified process to produce the new biosorbents, one part by weight of phosphoric acid with 6 parts by weight of carbonic acid and or thiocarbonic acid derivative, or a mixture of both, are dissolved in 100 parts by weight of dimethylformamide at 80 C. 10 parts by weight of residue of grain grinding is added to this solution, and the modification of the ground-grain residue is carried out according to the selected and determined conditions as described above.
In a particularly advantageous production process of biosorbents, according to the invention, 1 part by weight of phosphoric acid and 4 parts by weight of carbonic and/or thiocarbonic acid derivative, or a mixture of both, and possibly, in addition, 0.5 to 2 parts by weight of sodium triphosphate are dissolved or suspended in 30 parts by weight of distilled water. By adding 15 parts by weight of ground-grain residue to this solution or suspension and by mixing the components well, a dough-like mass is produced which is kept at 75 C for 15 hours. Thus, the modification of the residue of grain grinding, according to the above-mentioned conditions of reaction, is completed.
The residue of grain grinding required for the production of the biosorbents, according to the invention, is easily accessible, cheap by being the remainder of the grain grinding process, and easy to modify with inexpensive chemicals.
The invented production process can also be carried out in such a way that no aprotic, organic, and in many cases toxic and environmentally hazardous solvents have to be used. The metal-loaded biosorbents can be easily regenerated with diluted acids and subsequently re-used for metal absorption. Due to their bio-organic nature, biosorbents which have become unusable or are no longer completely regenerative can be combusted as an advantageous means of disposal so that only a small volume of inorganic material remains as residue. After becoming loaded with particularly problematic metal ions, e.g., radionuclides, the disposal of the biosorbents is much simpler compared to the conventional absorbers for radionuclides based on sythentic-organic polymers or inorganic absorbers. In addition, the invented bioabsorbers are biodegradable, so that after the binding of the radionuclides and the entailing removal of same from the environment, e.g., through composting or anaerobic fermentation whilst obtaining methane from bioabsorbers loaded with radionuclide, there is less special refuse.
The bioabsorbers derived from regenerative raw materials, preferably residue of grain grinding for metal-ion absorption, can be used for the metal-ion elimination from soakage water, watery solutions and extracts from soil, sludge, industrial residue and urban waste, as well as water from processing, and waste-water from energy-producing, material-transforming, municipal and agricultural enterprises.
The invention is explained below in greater detail by six examples.
Example 1 4 g of carbamide phosphate and 1 mL of concentrated sulphuric acid are dissolved at 60 C in 100 mL of dimethylformamide, and 10 g of dried residue of grain grinding is added to the solution. Whilst stirring, the suspension is slowly heated to 145 C, and at this temperature the suspension is continued to be stirred for 3 hours. The solid matter is filtered off and washed with water, 0.1 n of hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 3.85%, a sulphur content of 0.32%
and a phosphorus content of 3.15%. 1 g of dry bioabsorber is suspended in 25 mL of distilled water and filled into a chromatographic column, and the content of the column is set to a pH-value of 5Ø A cupric sulphate solution of the same pH-value is guided through the column in order to determine the bonding capacity of the bioabsorber. It amounts to 46 mg Cu per gram of bioabsorber.
Example 2 A mixture of 4 g of carbamide phosphate and 2 g of sodium triphosphate are dissolved at 80 C in 30 mL of water. By adding 5 g of residue of grain grinding to it and mixing the mixture well, a dough-like mass is produced. This mass is first of all kept at 75 C for 15 hours and afterwards for 2 hours at 150 C. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 3.64%, a sulphur content of 0.22%
and a phosphorus content of 4.11%. The binding capacity is determined as described in Example 1. It amounts to 52 mg Cu per gram of bioabsorber or 48 mg Co per gram of bioabsorber.
Example 3 g of thiocarbamide and 30 g of carbamide are dissolved together with 15 g of ortho-phosphoric acid at 75 C in 50 mL of dimethylformamide. 15 g of residue of grain grinding is added to this solution. By mixing this mixture well, a dough-like mass is produced.
This mass is first of all kept at 75 C for 15 hours and afterwards at 150 C
for 2 hours.
The dark mass is subsequently suspended in 150 mL of water, filtered off, and resuspended in a solvent mixture of 100 mL of ethanol and 20 mL of 0.1 n sodium lye and stirred at 80 C for one hour. After filtering off again, the solid matter is washed several times with water, 0.1 n hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 5.17%, a sulphur content of 2.85%, and a phosphorus content of 7.55%. The binding capacity is determined as described in Example 1. It amounts to 75 mg Cu per gram of bioabsorber or 210 mg Pb per gram of bioabsorber.
Example 4 30 g of carbamide and 15 g of ortho-phosphoric acid are dissolved at 75 C in 30 mL of water. 15 g of residue of grain grinding is added to this solution. By mixing this mixture well, a dough-like mass is produced. This mass is first of all kept for 15 hours at 75 C
and afterwards at 150 C for 2 hours. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 8.19%, a sulphur content of 0.38%
and a phosphorus content of 14.02%. The binding capacity is determined as described in Sample 1. It amounts per gram of bioabsorber to 145 mg Cu, 245 mg Ag, 165 mg Ni, 178 mg Co, 122 mg Cr, 117 mg Mo, 150 mg Zn, 132 mg Mn,385 mg Pb, 324 mg Hg, 275 mg Cd, 436 mg U, 356 mg Cs.
Example 5 20 g of semicarbazide hydrochloride and 10 g of polyphosphoric acid are dissolved at 80 C in 30 mL of water. 10 g of residue of grain grinding is added to the still warm solution. By mixing the mixture well, a dough-like mass is produced. This mass is first of all kept for 15 hours at 75 C and afterwards at 150 C for 4 hours. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 19.10%, a sulphur content of 0.18%
and a phosphorus content of 3.86%. The bonding capacity is determined as described in Example 1. It amounts to 85 mg Cu, 110 mg Ag, 65 mg Co, 201 mg Hg, 98 mg Cd or 197 mg U per gram of bioabsorber.
Example 6 20 g of aminoguanidine hydrogen carbonate, 2 g of sodium triphosphate and 10 g of ortho-phosphoric acid are separated from pH value 7.0 in 30 mL of 0.1 m phosphate buffer, and the pH-value of the solution is brought with 2 n sodium lye again to pH-value 7Ø 15 g of residue of grain grinding is added to the solution, and by mixing the mixture well a dough-like mass is produced. This mass is first of all kept for 10 hours at 75 C
and afterwards for 5 hours at 140 C. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 4.43%, a sulphur content of 0.56%
and a phosphorus content of 4.81%. The bonding capacity is determined as described in Example 1. It amounts to 55 mg Cu, 48 mg Zn, 162 Pb, 74 mg Cd or 148 mg Hg per gram of bioabsorber.
A special advantage of the biosorbents, according to the invention, is that the residue and waste material obtained from the food industry can be used as biosorbents.
Particularly the residue of grain-grinding which accumulates in flour mills as remainder, by which is meant the residue of the grain from which the flour has been extracted, is a potential material. Such residue has characteristics which make the latter especially suitable for the development of biosorbents. Said residue is insoluble in watery or organic solvents, and its change in volume is insignificant when subjected to a change in the pH-value or in ion strength. Furthermore, such residue is hydrophillic and can therefore very well tolerate being wetted with water. Thus, it is suited for work in aqueous media without restrictions. Due to the physical properties said residue is most suitable for the continuous application of metal-ion absorption in columns for the flow chromatography despite its bio-organic nature.
The biosorbents obtained according to the invented process, show a substantially improved binding capacity to metal ions, particularly, however, to heavy-metal ions and ions of radionuclides than the unmodified residue of grain grinding or the biosorbents of marine or microbial origin. Due to standardized production processes, reproducible binding rates for metal ions are available with respect to such biosorbents, which, however cannot be guaranteed for algae and microorganisms. In the latter case the metal-binding rate depends mainly on growth conditions. The biosorbents, according to the invention, bind univalent metal ions as well as metal ions of a higher valence and surpass in their binding capacity to heavy-metal ions and radionuclides the conventional absorbers of organic or inorganic origin.
In the compounds of the general formula (1) the following mean:
X = O,S, NH;
R1 = NH2, NH-NH2; and R2 = NH2, NH-NH2, NH-CO-NH2 N(CH3)-CH2-COOH.
N H-C Hz)3-C H( N HZ)-COO H
The invention relates, in addition, to a production process for biosorbents for metal ions on a bionatural basis in which the residue of grain grinding is treated with the above-described compound of the general formula (1) and subsequently separated. The residue of grain grinding is preferably processed in the presence of an acid. The duration of the treatment with the compound of the general formula (1) can range from 1 to 20 hours at a temperature of 50 to 200 C.
The modification is achieved in an organic solvent, a watery solution or a mixture of both.
Aprotic solvents with a higher boiling point, preferably dimethylformamide or dimethyl sulphoxide, are used as solvents. As watery solutions, it is preferable to use either distilled water or phosphate buffer with a pH-value of 5.0 to 8.0 and an ion strength ranging from 0.01 to 1 Mol/L, which may contain, in addition, polyphosphates and/or the salts thereof, or mixtures.of the above-mentioned organic solvents and watery solutions.
Sulphuric acid and/or phosphoric acid and/or polyphosphoric acid are used as acids.
A preferred production process is characterized by suspending the residue of grain grinding either in a solvent which contains a carbonic acid or thiocarbonic acid derivative or a mixture of both and possibly a dissolved acid. The suspensions are heated to 100 C
up to 200 C, preferably to 140 C up to 160 C whilst stirring. The stirring continues at the selected reaction temperature for 0.5 to 8 hours or, however, the suspension is processed into a disperse dough-like system by using the compounds of the general formula (1), which are dissolved in the solvents, and possibly an acid. Such dough is subjected for 2 to 20 hours, preferably 4 to 15 hours to a temperature of 60 C
to 100 C, preferably 700 to 80 C. The subsequent modification of the residue of grain grinding at temperatures of 120 C to 200 C, preferably 140 to 160 C is completed within 1 to 10 hours, preferably 2 to 5 hours. In both cases the duration of the heating depends on the selected temperature. The incubation can be accomplished statically or in a mobile manner by means of appropriate devices.
The weight ratios of the components to be used for the reactions can be chosen freely to a large extent. The weight ratio of the acid to the carbonic acid or thiocarbonic acid derivative, or a mixture of both is set to 0.1:2 up to 0.1:20, preferably 1:2 up to 1:6, and possibly by adding 0.1 up to 5 parts by weight, preferably 0.5 up to 2 parts by weight of a polyphosphate or its alkali salt. It is advantageous to produce a concentrated solution from the solvent used and the carbonic acid and/or thiocarbonic acid derivative, or a mixture of both.
In an exemplified process to produce the new biosorbents, one part by weight of phosphoric acid with 6 parts by weight of carbonic acid and or thiocarbonic acid derivative, or a mixture of both, are dissolved in 100 parts by weight of dimethylformamide at 80 C. 10 parts by weight of residue of grain grinding is added to this solution, and the modification of the ground-grain residue is carried out according to the selected and determined conditions as described above.
In a particularly advantageous production process of biosorbents, according to the invention, 1 part by weight of phosphoric acid and 4 parts by weight of carbonic and/or thiocarbonic acid derivative, or a mixture of both, and possibly, in addition, 0.5 to 2 parts by weight of sodium triphosphate are dissolved or suspended in 30 parts by weight of distilled water. By adding 15 parts by weight of ground-grain residue to this solution or suspension and by mixing the components well, a dough-like mass is produced which is kept at 75 C for 15 hours. Thus, the modification of the residue of grain grinding, according to the above-mentioned conditions of reaction, is completed.
The residue of grain grinding required for the production of the biosorbents, according to the invention, is easily accessible, cheap by being the remainder of the grain grinding process, and easy to modify with inexpensive chemicals.
The invented production process can also be carried out in such a way that no aprotic, organic, and in many cases toxic and environmentally hazardous solvents have to be used. The metal-loaded biosorbents can be easily regenerated with diluted acids and subsequently re-used for metal absorption. Due to their bio-organic nature, biosorbents which have become unusable or are no longer completely regenerative can be combusted as an advantageous means of disposal so that only a small volume of inorganic material remains as residue. After becoming loaded with particularly problematic metal ions, e.g., radionuclides, the disposal of the biosorbents is much simpler compared to the conventional absorbers for radionuclides based on sythentic-organic polymers or inorganic absorbers. In addition, the invented bioabsorbers are biodegradable, so that after the binding of the radionuclides and the entailing removal of same from the environment, e.g., through composting or anaerobic fermentation whilst obtaining methane from bioabsorbers loaded with radionuclide, there is less special refuse.
The bioabsorbers derived from regenerative raw materials, preferably residue of grain grinding for metal-ion absorption, can be used for the metal-ion elimination from soakage water, watery solutions and extracts from soil, sludge, industrial residue and urban waste, as well as water from processing, and waste-water from energy-producing, material-transforming, municipal and agricultural enterprises.
The invention is explained below in greater detail by six examples.
Example 1 4 g of carbamide phosphate and 1 mL of concentrated sulphuric acid are dissolved at 60 C in 100 mL of dimethylformamide, and 10 g of dried residue of grain grinding is added to the solution. Whilst stirring, the suspension is slowly heated to 145 C, and at this temperature the suspension is continued to be stirred for 3 hours. The solid matter is filtered off and washed with water, 0.1 n of hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 3.85%, a sulphur content of 0.32%
and a phosphorus content of 3.15%. 1 g of dry bioabsorber is suspended in 25 mL of distilled water and filled into a chromatographic column, and the content of the column is set to a pH-value of 5Ø A cupric sulphate solution of the same pH-value is guided through the column in order to determine the bonding capacity of the bioabsorber. It amounts to 46 mg Cu per gram of bioabsorber.
Example 2 A mixture of 4 g of carbamide phosphate and 2 g of sodium triphosphate are dissolved at 80 C in 30 mL of water. By adding 5 g of residue of grain grinding to it and mixing the mixture well, a dough-like mass is produced. This mass is first of all kept at 75 C for 15 hours and afterwards for 2 hours at 150 C. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 3.64%, a sulphur content of 0.22%
and a phosphorus content of 4.11%. The binding capacity is determined as described in Example 1. It amounts to 52 mg Cu per gram of bioabsorber or 48 mg Co per gram of bioabsorber.
Example 3 g of thiocarbamide and 30 g of carbamide are dissolved together with 15 g of ortho-phosphoric acid at 75 C in 50 mL of dimethylformamide. 15 g of residue of grain grinding is added to this solution. By mixing this mixture well, a dough-like mass is produced.
This mass is first of all kept at 75 C for 15 hours and afterwards at 150 C
for 2 hours.
The dark mass is subsequently suspended in 150 mL of water, filtered off, and resuspended in a solvent mixture of 100 mL of ethanol and 20 mL of 0.1 n sodium lye and stirred at 80 C for one hour. After filtering off again, the solid matter is washed several times with water, 0.1 n hydrochloric acid and distilled water and dried at 100 C.
This bioabsorber has a nitrogen content of 5.17%, a sulphur content of 2.85%, and a phosphorus content of 7.55%. The binding capacity is determined as described in Example 1. It amounts to 75 mg Cu per gram of bioabsorber or 210 mg Pb per gram of bioabsorber.
Example 4 30 g of carbamide and 15 g of ortho-phosphoric acid are dissolved at 75 C in 30 mL of water. 15 g of residue of grain grinding is added to this solution. By mixing this mixture well, a dough-like mass is produced. This mass is first of all kept for 15 hours at 75 C
and afterwards at 150 C for 2 hours. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 8.19%, a sulphur content of 0.38%
and a phosphorus content of 14.02%. The binding capacity is determined as described in Sample 1. It amounts per gram of bioabsorber to 145 mg Cu, 245 mg Ag, 165 mg Ni, 178 mg Co, 122 mg Cr, 117 mg Mo, 150 mg Zn, 132 mg Mn,385 mg Pb, 324 mg Hg, 275 mg Cd, 436 mg U, 356 mg Cs.
Example 5 20 g of semicarbazide hydrochloride and 10 g of polyphosphoric acid are dissolved at 80 C in 30 mL of water. 10 g of residue of grain grinding is added to the still warm solution. By mixing the mixture well, a dough-like mass is produced. This mass is first of all kept for 15 hours at 75 C and afterwards at 150 C for 4 hours. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 19.10%, a sulphur content of 0.18%
and a phosphorus content of 3.86%. The bonding capacity is determined as described in Example 1. It amounts to 85 mg Cu, 110 mg Ag, 65 mg Co, 201 mg Hg, 98 mg Cd or 197 mg U per gram of bioabsorber.
Example 6 20 g of aminoguanidine hydrogen carbonate, 2 g of sodium triphosphate and 10 g of ortho-phosphoric acid are separated from pH value 7.0 in 30 mL of 0.1 m phosphate buffer, and the pH-value of the solution is brought with 2 n sodium lye again to pH-value 7Ø 15 g of residue of grain grinding is added to the solution, and by mixing the mixture well a dough-like mass is produced. This mass is first of all kept for 10 hours at 75 C
and afterwards for 5 hours at 140 C. The dark mass is subsequently suspended in 150 mL of water, filtered off, and washed several times with water, 0.1 n hydrochloric acid and distilled water, and dried at 100 C.
This bioabsorber has a nitrogen content of 4.43%, a sulphur content of 0.56%
and a phosphorus content of 4.81%. The bonding capacity is determined as described in Example 1. It amounts to 55 mg Cu, 48 mg Zn, 162 Pb, 74 mg Cd or 148 mg Hg per gram of bioabsorber.
Claims (12)
1. Biosorbents for metal ions on a biological-natural base, characterized in that they consist of residue from grain grinding in an aqueous system and/or particles insoluble in organic solvents, which have been modified through treatment with a combination of the general formula I
wherein X=O,S or NH
R1 = NH2, NH-NH2 and R2 = NH2, NH-NH2, NH-CO-NH2, N(HC3)-CH2-COOH, NH-(CH2)3-CH(NH2)-COOH, and acids, such that the nitrogen content is in the range of 0.1 to 20%, the phosphor content in the range of 0.1 to 20%, and the sulphur content in the range of 0.1 to 8%.
wherein X=O,S or NH
R1 = NH2, NH-NH2 and R2 = NH2, NH-NH2, NH-CO-NH2, N(HC3)-CH2-COOH, NH-(CH2)3-CH(NH2)-COOH, and acids, such that the nitrogen content is in the range of 0.1 to 20%, the phosphor content in the range of 0.1 to 20%, and the sulphur content in the range of 0.1 to 8%.
2. Biosorbents according to Claim 1, characterized in that the nitrogen content lies in the range of 4 to 15% and the phosphor content in the range of 6 to 15%.
3. Biosorbents according to Claim 1 or 2, characterized in that the particles are spherical.
4. Biosorbents according to at least one of Claims 1 to 3, characterized in that the cereal grains are selected from wheat, barley, oats, rye, triticale, millet, maize and rice grains.
5. Method for the production of biosorbents according to at least one of Claims 1 to 4, characterized in that the residue from grain grinding is treated at 50 to 200 °C over a time span of 1 to 20 hours with a combination of the general formula I, wherein the general formula I is as defined in Claim 1, and with an acid, and subsequently separated.
6. Procedure according to Claim 5, characterized in that the residue from grain grinding moves in suspension in water solution and/or organic solvents and is treated at 100 to 200 °C over a time span of 0.5 to 8 hours.
7. Procedure according to Claim 6, characterized in that the treatment is done at 140 to 160 °C.
8. Method according to at least one of Claims 5 to 7, characterized in that the residue from grain grinding is processed with the combination of the general formula (1) in a aqueous solvent and/or organic solvent into a dispersed, pasty mush, that this mush is kept for 2 to 20 hours at a temperature of 60 to 100 °C, and that afterwards, the modification of the residue from grain grinding occurs at temperatures of 120 to 200 °C in the course of 1 to 10 hours.
9. Method according to Claim 8, characterised in that the pasty mush is left at a temperature of 70 to 80 °C over a time span of 4 to 15 hours, and that the modification at 140 to 160 °C is done over 2 to 5 hours.
10. Method according to at least one of Claims 5 to 9, characterized in that the weight ratio of the acids to the combination of the general formula (1) is set at 0.1 : 2 to 0.1 :
20.
20.
11. Method according to Claim 10, characterized in that the weight ration is set at 1 : 2 to 1 : 6.
12. Method according to at least one of Claims 5 to 11, characterized in that in the treatment, a polyphosphate or one of its alkali salts is added.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19718452.9 | 1997-04-30 | ||
| DE19718452A DE19718452C2 (en) | 1997-04-30 | 1997-04-30 | Biosorbents for metal ions and process for their manufacture |
| PCT/EP1998/001827 WO1998048933A1 (en) | 1997-04-30 | 1998-03-27 | Biosorption agents for metal ions and method for the production thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2282432A1 CA2282432A1 (en) | 1998-11-05 |
| CA2282432C true CA2282432C (en) | 2007-09-18 |
Family
ID=7828338
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2282432 Expired - Fee Related CA2282432C (en) | 1997-04-30 | 1998-03-27 | Biosorption agents for metal ions and method for the production thereof |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0979143B1 (en) |
| JP (1) | JP2001522301A (en) |
| AT (1) | ATE284754T1 (en) |
| CA (1) | CA2282432C (en) |
| DE (2) | DE19718452C2 (en) |
| HU (1) | HUP0001724A3 (en) |
| WO (1) | WO1998048933A1 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10005681B4 (en) | 2000-02-07 | 2005-06-16 | Atc Dr. Mann E.K. | Method and device for the decontamination of metal-containing waters |
| DE10045788A1 (en) * | 2000-09-07 | 2002-04-04 | Atc Dr Mann | Process for reducing the volume of radioactive waste |
| WO2003084878A1 (en) * | 2002-04-05 | 2003-10-16 | Atc Dr. Mann E.K. | Use of agricultural grains, plant parts thereof, and grinding residues for decontaminating waters that are polluted with chlorinated hydrocarbon |
| DE10361872A1 (en) * | 2002-12-20 | 2004-07-01 | Atc Dr. Mann E.K. | Use of renewable resource materials as adsorbents for decontaminating drug-contaminated water |
| US7803937B2 (en) | 2003-10-31 | 2010-09-28 | Kowa Co., Ltd. | Cellulose II phosphate ester and metal-adsorbing material using the same |
| JP4702874B2 (en) * | 2004-10-08 | 2011-06-15 | ミヨシ油脂株式会社 | Heavy metal-containing waste treatment agent and heavy metal-containing waste treatment method |
| JP4562128B2 (en) * | 2004-12-02 | 2010-10-13 | ミヨシ油脂株式会社 | Waste disposal method |
| DE102007003410B4 (en) | 2007-01-23 | 2012-07-12 | Produktions- Und Umweltservice Gmbh | Ion exchange filter cartridge made from modified natural fiber yarns for the removal of particles, heavy metals and hardness formers in water treatment and their production |
| DE102011114952A1 (en) | 2011-10-06 | 2013-04-11 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Adsorbent for the separation of fluorinated organic compounds from contaminated fluids, process for its preparation and use thereof |
| CN113398889B (en) * | 2021-06-10 | 2022-10-11 | 广西大学 | Multi-adsorption-site biomass-based hyperbranched multi-metal ion adsorption material and preparation method and application thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2205805A5 (en) * | 1972-10-10 | 1974-05-31 | Escorblac Michel | Absorbent material from corn-cobs - by fragmenting, grinding, classifying, screening and sifting |
| DE4203928A1 (en) * | 1992-02-11 | 1993-08-12 | Juergen Buil | Binder for removing mineral oils, chemicals or liquids - comprising comminuted cereal grains puffed by heat |
| DE4239749C2 (en) * | 1992-11-26 | 1996-05-30 | Meisch Hans Ulrich Prof Dr | Phosphorylated wood |
| WO1995002452A1 (en) * | 1993-07-15 | 1995-01-26 | Boris Afanasjevitch Velitchko | Process for preparing sorbents from polysaccharide-containing raw materials, sorbents and their use |
| KR0150855B1 (en) * | 1995-10-20 | 1998-08-17 | 강재헌 | Heavy metal biosorbent extracted from biomass |
-
1997
- 1997-04-30 DE DE19718452A patent/DE19718452C2/en not_active Expired - Fee Related
-
1998
- 1998-03-27 EP EP98919178A patent/EP0979143B1/en not_active Expired - Lifetime
- 1998-03-27 AT AT98919178T patent/ATE284754T1/en not_active IP Right Cessation
- 1998-03-27 HU HU0001724A patent/HUP0001724A3/en unknown
- 1998-03-27 WO PCT/EP1998/001827 patent/WO1998048933A1/en active IP Right Grant
- 1998-03-27 JP JP54652298A patent/JP2001522301A/en active Pending
- 1998-03-27 CA CA 2282432 patent/CA2282432C/en not_active Expired - Fee Related
- 1998-03-27 DE DE59812388T patent/DE59812388D1/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2282432A1 (en) | 1998-11-05 |
| HUP0001724A2 (en) | 2000-10-28 |
| EP0979143A1 (en) | 2000-02-16 |
| DE59812388D1 (en) | 2005-01-20 |
| HUP0001724A3 (en) | 2001-11-28 |
| WO1998048933A1 (en) | 1998-11-05 |
| ATE284754T1 (en) | 2005-01-15 |
| JP2001522301A (en) | 2001-11-13 |
| DE19718452A1 (en) | 1998-11-05 |
| EP0979143B1 (en) | 2004-12-15 |
| DE19718452C2 (en) | 2001-09-13 |
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