DE102004032255A1 - Method for removing dissolved heavy metals, transition metals and/or metalloids from aqueous solution comprises contacting the solution with a water-insoluble hydrophilic polymer complex structure unit present in particle form - Google Patents

Abstract

Method for removing dissolved heavy metals, transition metals and/or metalloids (I) from aqueous solution (II) comprises contacting (by passing) (II) with a water-insoluble hydrophilic polymer complex structure unit (III) (present in particle form) (where recurring metal complex structure unit has at least one formula of (A), (A1) or (A2)) and cross-linking bridges. Method for extracting dissolved heavy metals, transition metals and/or metalloids (I) from aqueous solution (II) comprises contacting (by passing) (II) with a water insoluble hydrophilic polymer complex structure unit (III) (present in particle form) (where recurring metal complex structure unit has at least one formula of (A), (A1) or (A2)) and cross-linking bridges. R : H or optionally substituted alkyl residue; T1>optionally over a electrophilic link with N connected with at least one thiol- or thione group (preferably thiocarbamoyl group) or with at least a thiol group substituted alkyl- or aryl carbonyl group to form metal chelate; and T2>thiocarbamate (preferably over a N-atom bounded heterocyclic residue with at least a thiol- or thione group or with at least a thiol group substituted alkyl- or aryl carbonamide group to form metal chelate. An independent claim is also included for a hydrophilic polymeric complex former (in fine particulate form and filterable) obtained by cross linking a water-insoluble hydrophilic copolymer (IV) of formula [-(A3)m-(B1)-(C1)o-(D)p-(E)q-(F1)r-] (where (A3), (B1), (C1), (D), (E) and (F) are copolymerized monomers) and where at least one-third of the copolymerized monomer (A3) and (B1) reacts with (A), (A1) or (A2). A3 : allylamine, monosubstituted allylamine or diallylamine (in free form or in salt form); B1 : diacetone acrylamide; C1 : (meth)acrylamide or 2-hydroxy ethyl acrylate; D : (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, methacryloyloxy ethane sulfonic acid, 2-acryl amido-2-methpropane sulfonic acid (in free form or in salt form); E : ester of (meth)acryl-, maleic- or itaconic acid, N-tert.butyl acrylamide, styrene, N-vinylpyrrolidone or N-vinylcaprolactam; F1 : bifunctional, trifunctional or tetra functional monomer of acrylamide, methacrylamide or (meth)acryl ester; and m-r : relative portion of the monomer at the copolymer in mol percent (where m, n are 0-69.5 mol.% (with the proviso that m+n is greater than or equal to 15 mol.% and m is greater than or equal to 10 mol.% (when n is less than or equal to 10 mol.%)), o is 0-80 mol%, p is 0-50 mol.% (with the proviso that o+p is greater than or equal to 30 mol.%), q is 0-50 mol.% and r is 0.5-10 mol.%. [Image].

Description

1 Introduction:

The The invention relates to a method for the extraction of metals aqueous solutions below Use of new water-insoluble hydrophilic polymer with metal-binding groups.

Under In the context of the invention, the term "metals" is used to refer to heavy metals dissolved in water, especially dissolved in water Compounds of transition metals and / or semi-metals as well as simple or complex salts of precious metals understood that in neutral to acidic solution at least in part present as cations.

among them In particular, salts of copper, silver, gold, zinc, cadmium, Mercury, tin, lead, iron, cobalt, nickel, ruthenium, rhodium, Palladium, osmium, iridium and platinum understood, as well as salts of Vanadium, manganese, rhenium, thorium, uranium and antimony hydroxide and arsenic acid.

The The method firstly aims at the removal of heavy metals diluted aqueous solutions, which are harmless as waste quality be released to the environment and have to be detoxified.

The Second, the process aims at the enrichment of valuable metals from heavily diluted aqueous solutions of their Salts, the valuable transition metals besides worthless alkaline earth and earth metals.

The Third, the process aims at the extraction of heavy metals in the Framework of mining after the leaching process.

2. State of the art:

With Heavy metals contaminated aqueous solutions fall in all industrial processes in which metals are recovered and are processed.

The usual today The extraction of precious and non-ferrous metals is largely based on the extraction of ore concentrates by mining of ores and enrichment to concentrates, mostly by the technique of flotation in aqueous turbid.

One newer process for processing ores, which has many disadvantages The flotation process avoids the leaching process in particular in the form of the "bio-leaching", in which shredded Erzhaltiges rock treated with acidic aqueous solutions which is the metal in the form of dissolved salts take up. The for the leaching required acidity can by adding mineral acid, especially sulfuric acid, be discontinued or become bacterial through the process Stop processes by yourself. The leaching process can in the ore deposit be made even if sufficient comminution of the ore body is taken care of.

The Obtaining the metal from the acidic solutions may e.g. by separation and enrichment by means of liquid-liquid extraction, by electrolysis or by cementation with a less noble metal, e.g. Zinc or iron. The process has for oxidic and heavily oxidized sulfidic ores meaning, however, it has the Disadvantage, on ores with a high proportion of carbonate gangue because of the release of big ones Amounts of carbon dioxide hardly applicable. It is playing an increasingly important role in the extraction of copper from old mining dumps and from the recovery of the so-called "iron Hutes "of copper deposits.

The Enrichment of the Wertmetallanteils can except by liquid-liquid extraction also by ion exchange and the like Processes take place.

A Also important is the treatment of waters that the natural one Returned cycle or waters, intended for use, but contaminated by heavy metal salts are. Such solutions arise from the commercial use of service water, from precipitation or groundwater by contact with metal salt soils, with Tailings or landfill material; they are often poisonous and make one Environmental hazard.

For the distance heavy metal freight, e.g. the salts of zinc, cadmium, lead, Copper, silver, mercury, from contaminated water are processes become known, which are based on the principle of biosorption. there The heavy metals are added to water treatment plants by adding killed microorganisms, which has a high absorption capacity for heavy metals show to those killed Microorganisms bound and with these by filtration or flotation removed from the water. The method is state of the art. In this context, a large number of works refer to some are selected below are:

• Zouboulis, A.I .; Rousou, E.G .; Matis, K.A .; Hancock, I.C. "Removal of toxic metals of aqueous mixtures: Part 1. Biosorption ", J. Chem. Tech. Biotechnol. 1999, 74, 429-436.
• Kefala, M.I .; Zouboulis, A.I .; Matis, K.A. "Biosorption of cadmium ions by Actinomycetes and separation by flotation ", Envir. Pollution 1999, 104, 283-293.
• Eccles, H. "Treatment of metal-contaminated wastes: why select a biological process? ", Trends Biotech. 1999, 17 (12), 462-465.
• Aldrich, C .; Feng, D. "Removal of heavy metals from wastewater effluents by biosorptive flotation ", Miner. Eng. 2000, 13, 1129-1138.

3. Object of the invention:

Of the Invention has for its object to provide a method with the heavy metal salt-containing aqueous solutions also in high dilution a simple extractive treatment of the part of their metal freight can be exempted, which accounts for heavy metals. The process has primarily for mining, water management and the environmental engineering importance.

4. Subject of the invention

The The invention relates to the extraction of heavy metal ions from aqueous solutions under Use of a solid, water-insoluble polymeric sorbent in particle form.

It is known that many hydrophilic polymers after introduction certain functional groups are suitable for a variety diluted from metal ions aqueous solutions remove.

The inventive method is based on the fact that the heavy metal-containing aqueous solutions with a hydrophilic but water-insoluble Polymer containing metallophilic groups, whereby the content of heavy metal ions or semimetal compounds an environmentally friendly and harmless level is lowered.

4.1. The extraction process

worin die Reste R, T und T' die nachfolgende Bedeutung haben:

R:

H oder ein gegebenenfalls substituierter Alkylrest, z.B. eine Carboxymethylgruppe;

T:

ein ggf. über ein elektrophiles Bindeglied mit N verbundener Rest mit mindestens einer zur Bildung von Metallchelaten befähigte Thiol- oder Thiongruppe, insbesondere eine Thiocarbamoylgruppe oder eine mit mindestens einer Thiolgruppe substituierte Alkyl- oder Arylcarbonylgruppe;

T':

eine Thiocarbamatgruppe, ein bevorzugt über ein N-Atom angebunder heterocyclischer Rest mit mindestens einer zur Bildung von Metallchelaten befähigten Thiol- oder Thiongruppe, oder eine mit mindestens einer Thiolgruppe substituierte Alkyl- oder Arylcarbonamidgruppe, z.B. eine Mercaptoacetamidogruppe oder eine 2,3-Dimercaptopropionamidogruppe.

An object of the invention is therefore a process for the removal of salt-like dissolved heavy metals, transition metals and / or semimetals from aqueous solutions and is characterized in that the solution is temporarily brought into contact with a present in particulate water-insoluble hydrophilic polymeric complexing agent, the recurring metal complex forming Contains structural units of at least one of the formulas (A '), (A'') and (B') and has crosslinking bridges,

in which the radicals R, T and T 'have the following meaning:

R:

H or an optionally substituted alkyl radical, for example a carboxymethyl group;

T:

a radical possibly linked via an electrophilic linker to N with at least one thiol or thione group capable of forming metal chelates, in particular a thiocarbamoyl group or an alkyl or arylcarbonyl group substituted by at least one thiol group;

T ':

a thiocarbamate group, a heterocyclic radical preferably bonded via an N atom with at least one thiol or thione group capable of forming metal chelates, or an alkyl or arylcarbonamide group substituted by at least one thiol group, for example a mercaptoacetamido group or a 2,3-dimercaptopropionamido group.

Under The term thiocarbamate group is derived from thiocarbamic acid Understood partial structures: the Dithiocarbamatrest, the Thiourethanrest, the thiourea radical, the latter also in the form of one or more times substituted derivatives.

The crosslinks can For example, be formed by that for the production of the water Hydrohilic polymer used comonomer mixture at least 0.5 mol% Contains monomer units, especially those derived from a moder polyfunctional monomer which are two to four polymerizable double bonds wearing.

Networking bridges can be found in the Sense of the invention also be formed by nucleophilic groups, e.g. primary or secondary Amino groups, with electrophilic groups, e.g. a methylol group or a carboxylic acid anhydride group be implemented in another chain or chain segment.

To Absorption of the metal ion content from the solution may be hydrophilic, but water-insoluble polymer completely separated by filtration, flocculation, centrifugation and / or flotation become. The particulate water-insoluble hydrophilic Polymer can also be on a carrier be applied and so with the metal salt solution in Be brought in contact, for example as a coating on a or two-sided coated film.

With the inventive method succeeds in a simple manner, dilute aqueous solutions of heavy metal salts or compounds to the metal content by simply bringing into contact revoke. It is sufficient, the polymers of the invention as an aqueous suspension in the metal salt-containing aqueous solution spread over to keep it in contact for a certain amount of time and then to separate it again.

The inventive method allows it, an aqueous solution that by contact with a heavy metal containing material, for Example by leaching an ore body or when passing through one burdened with ore residues Soil loaded with metal salts, the heavy metal content with simple To withdraw procedural steps.

Appropriate waters can be: water from metal contaminated natural springs, rainwater, that has gone through mine dumps or metal-laden aquifers, leach solutions from the leaching process, acid residue solutions from ore mines, metallurgical wastewater, foundry wastewater, wastewater Galvanizing plants, other industrial wastewater, landfill wastewater, solutions, in the wet cleaning of polluted soils attack.

The inventive method is especially for waters or aqueous solutions suitable, containing the compounds of the following metals: tin, lead, copper, Silver, Gold, Zinc, Cadmium, Mercury, Indium, Thallium, Arsenic (III), Antimony (III), selenium (IV), vanadium, chromium, manganese, iron, cobalt, Nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum. It is for the extraction of concentrate solutions expensive metals from low concentrated and heavily oxidized sulfidic Ores are especially valuable.

The Metal extraction can also be done by the metal-containing aqueous solution in a fluidized bed from the aqueous suspension at least one water-insoluble, but hydrophilic polymeric complexing agent is introduced and is separated again after some time. The separation can for Example by sedimentation and decantation, by filtration or over Diaphragm be effected. A particularly fast acting form of the Gravity separation can be the separation of a loaded polymer be with a centrifuge.

A third possibility is to apply the water-insoluble but hydrophilic polymeric complexing agent together with a binder to a band-shaped carrier and to bring it into contact with the metal salt-loaded water in loose or rolled-up form or in the form of chips. A suitable system is described in DE 197 20 538 A1 ,

in the technical scale may be the separation of a polymer loaded with the heavy metal according to the invention Complexing agent especially be effected by flotation, in particular by a process the principle of "dissolved air flotation ". An thereby to be solved Problem is the use of "collectors" and "foaming agents" for the deposition of the loaded polymer, but after flotation should not remain in the water. This problem can be caused by the use of volatile collectors such as ethanol or of cationic polymers, e.g. of cationic strength in small Concentrations, dissolved become.

Also can the back from with a polymer according to the invention coated leaflets or Schnitzeln be designed so that they are the flotative separation without the use of water-polluting frothers or collectors. This is e.g. by laminating the backside with a hydrophobic medium possible.

4.2. The polymeric complexing agents

The hydrophilic, but water-insoluble polymeric complexing agents used as sorbents for heavy metals are new. They consist of finely divided particles and are prepared from novel copolymers of general formula I by introducing special functional groups. - (A) _m - (B) _n - (C) _o - (D) _p - (E) _q - (F) _r - I

A:

Allylamin, ein monosubstituiertes Allylamin, oder Diallylamin, in freier Form oder in Form eines Salzes;

B:

Diacetonacrylamid;

C:

Acrylamid, Methacrylamid, N-(2-Hydroxyethyl)acrylamid, 2-Hydroxyethylacrylat;

D:

Acrylsäure, Methacrylsäure, Crotonsäure, Itaconsäure, Maleinsäure, Fumarsäure, Methacryloyloxyethansulfonsäure, 2-Acrylamido-2-methylpropansulfonsäure, Acrylamidomethansulfonsäure, gegebenenfalls einfach veresterte Acrylamidomethanphosphonsäure, N-Acryloyltaurin in freier Form oder in Salzform;

E:

ein Ester der Acryl-, Methacryl-, Malein- oder Itaconsäure, insbesondere Butylacrylat oder Methylmethacrylat, ferner N-tert.Butylacrylamid, Styrol, N-Vinylpyrrolidon, N-Vinylcaprolactam;

F:

ein Monomer, welches Vernetzungsbrücken bereitstellt, insbesondere ein bifunktionelles, trifunktionelles oder tetrafunktionelles Monomer aus der Reihe der Acrylamide, Methacrylamide, Acrylester, Methacrylester;

m, n:

jeweils 0 – 69,5 mol-%, mit der Maßgabe, dass m + n ≥ 15 mol-%, und dass m ≥ 10 mol %, wenn n ≤ 10 mol-%;

o:

0 – 80 mol-%, p: 0 – 50 mol-%, mit der Maßgabe, dass + p ≥ 30 mol-%;

q:

0 – 50 mol-%;

r:

0,5 – 10 mol-%.

In formula I designate
(A), (B), (C), (D), (E) and (F) copolymerized monomers, and
m, n, o, p, q and r are the relative proportions of monomers in the copolymer in terms of mole percent, according to the following definition:

A:

Allylamine, a monosubstituted allylamine, or diallylamine, in free form or in the form of a salt;

B:

diacetone;

C:

Acrylamide, methacrylamide, N- (2-hydroxyethyl) acrylamide, 2-hydroxyethyl acrylate;

D:

Acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, methacryloyloxyethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidomethanesulfonic acid, optionally monounsaturated acrylamidomethanephosphonic acid, N-acryloyltaurine in free form or in salt form;

e:

an ester of acrylic, methacrylic, maleic or itaconic acid, in particular butyl acrylate or methyl methacrylate, furthermore N-tert-butylacrylamide, styrene, N-vinylpyrrolidone, N-vinylcaprolactam;

F:

a monomer providing crosslink bonds, in particular a bifunctional, trifunctional or tetrafunctional monomer from the series of acrylamides, methacrylamides, acrylic esters, methacrylic esters;

m, n:

each 0 - 69.5 mol%, with the proviso that m + n ≥ 15 mol%, and that m ≥ 10 mol%, when n ≤ 10 mol%;

O:

0 - 80 mol%, p: 0 - 50 mol%, with the proviso that + p ≥30 mol%;

q:

0-50 mol%;

r:

0.5-10 mol%.

In the invention for metal extraction copolymer used is at least one third of the copolymerized Monomers (A) and / or (B) to a metal-binding monomer of Formula (A '), (A' ') or (B') implemented.

The Copolymer I contains as well as the copolymer of the present invention prepared therefrom 0.5-10 mol% copolymerized monomer units that form crosslink bridges, in particular those derived from a bi- or polyfunctional monomer which are two to four polymerizable double bonds wearing.

Networking bridges can be found in the Sense of the invention also be formed by the fact that nucleophilic Groups, e.g. the primary or secondary Amino groups of the monomer portion (A) with electrophilic groups, e.g. one Methylol group or a carboxylic acid anhydride group in one another chain or chain segment.

The Monomer units A and / or B, which in the finished polymer is a thione or thiol group, e.g. carry a thiocarbamate group, so be after the construction of the copolymer skeleton in a second step with the functional group T or T ', where the metal chelating monomer units A ', A ", B' result.

to later Modification by thiocarbamoyl groups or mercaptoalkanoyl groups suitable copolymerized monomers are, for example, allylamine, N-methylallylamine, N-ethylallylamine, N-allylaminoacetic acid, 4-sulfobutylallylamine, Diallylamine.

Polymers containing copolymerized allylammonium salts and processes for their preparation are known from the application US 4,329,441 known.

The Preparation of corresponding polymers is preferably carried out by containing radical polymerization of allylammonium salts Monomergemischen and provides a copolymer corresponding to the formula I. and contains at least 3 monomers, wherein the individual comonomers are represented by the relative proportion m, n, o, p, q and r represents which represents the composition of the starting monomer mixture in mole percent and therefore normative.

in the Purpose of the invention provide allylammonium salts and diallylammonium salts particularly easy to functionalize and therefore preferred monomer units (A) dar. However, it comes for the polymerization also questioned other allylamine-type monomers, for example, allylaminomethanesulfonic acid, 4- (N-allylamino) butanesulfonic acid, Hydrochloride of N-allylglycine or 4- (N-allylamino) butyric acid.

Out J. Am. 79, 3128-3131 [1958] and J. Am. Chem. Soc. 80, 3615-3618 [1958] it is known that diallylammonium salts be incorporated in the radically initiated copolymerization so that a cyclic Structure arises, for which is assumed to be a piperidine ring as a structural element. The polymers described are not networked.

The Monomer unit (C) is above all the comonomer portion, which ensures that yourself the copolymer is pH-independent behaves hydrophilic. Especially for that suitable monomers are: acrylamide, methacrylamide, hydroxyethyl acrylate.

The Monomer unit (D) stands for the comonomer fraction, the one for it make sure that Polymer at pH values> 4 behaves hydrophilic, it determines the charge character of the copolymer and thus the Neutral salt tolerance in neutral and alkaline solution. Cheap Monomers are: acrylic acid, Methacrylic acid, fumaric acid, maleic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, methacryloyloxyethanesulfonic acid.

From At least one of the comonomers (C) and (D) is present in the copolymer.

The Monomer unit (E) significantly determines the particle properties the copolymers and their behavior towards organic solvents. Particularly suitable monomers are: butyl acrylate, methyl methacrylate, N-tert-butylacrylamide, N-vinylpyrrolidone.

The Copolymers of the formula I contain at least 0.5 mol% of a monomer, the networking bridges preferably in the form of one of (F) above bifunctional or trifunctional Monomers.

The Monomer unit (F) determines as crosslinkers - on the density of the crosslinking bridges - essential the swellability of the polymers and thus the penetration of aqueous solutions.

(F) stands especially for Esters and amides of acrylic acid or methacrylic acid, that of bifunctional or polyfunctional alcohols or amines are derived. Therefore typical monomers are ethylene glycol diacrylate, tris-methylolpropane triacrylate, Pentaerythritol tetraacrylate, methylenebisacrylamide, 1,3-bis-acrylamidopropane, Trisacryloylhexahydro-s-triazine. Cheap networking bridges Comonomers are also hydroxymethylacrylamide, methoxymethylacrylamide, Hydroxymethylmethacrylamide or methoxymethylmethacrylamide.

In the copolymers of allylammonium and diallylammonium salts (A) the monomer units are due to the production initially in Form of neutral salts. The later Incorporation of a thiol or thione group T in copolymers of the formula I can only over free primary or secondary Amino groups are carried out in the polymer I by reaction with bases released and to an isothiocyanate or an isothiocyanate precursor compound can be added. The isothiocyanate precursor compound reacts under the reaction conditions as the equivalent of an isothiocyanate.

The Copolymerization of allylammonium salts and diallylammonium salts is suppressed by the presence of free allylic amines. she is therefore bound to the presence of strong acid anions. Are cheap Chloride or the anions of sulfonic acids, including trifluoroacetate comes question.

From that Apart from that, the copolymerization of allylammonium salts is difficult and leads without special radical polymerization neither too high Incorporation rates still acceptable copolymer yields. The copolymerization Allylammonium salts and diallyl ammonium salts in non-aqueous solution succeed only in the presence of special co-initiators or chain transfer.

From the US 4,329,441 It is known that the copolymerization of allylammonium salts and diallylammonium salts in the presence of phosphorus compounds with a PH bond leads to high polymer yields. Particularly favorable compounds are dialkyl phosphites and alkyl or aryl phosphinates. Phosphoric acid, benzene-phosphinic acid and diphenylphosphine oxide are also fundamentally suitable as chain transfer agents for the purposes of the invention.

As well leads the Use of aliphatic, aromatic or heterocyclic Thiols, or enolisable thiones, as chain transfer agents for efficient incorporation of allylammonium groups in copolymers.

DE 29 44 092 A1 contains a description of the process steps according to which suitable polymers are prepared by a precipitation polymerization of ethylenically unsaturated monomers in the presence of a radical initiator and at least one thiol. The process described is also suitable for the preparation of polymers having primary or secondary ammonium groups, from which polymers modified according to the invention by thiocarbamoyl groups T are available. The polymerization is preferably carried out under reflux conditions, ie preferably at temperatures between 80 and 100 ° C. A particularly favorable solvent for the polymerization is t-butanol.

Homo- and copolymers containing diacetoneacrylamide monomer units (B) are known for more than four decades. The installation of the metallophilic Structural element T 'takes place in the case of polymers containing diacetone acrylamide by reacting the keto group with a hydrazine derivative, e.g. one Dithiocarbazate, a derivative of thiosemicarbazide or one of them derived heterocyclic N-amino compound, for example a Derivative of 3-mercapto-4-amino-1,2,4-triazole.

It is known that ketone derivatives of thiocarbazic acids are in equilibrium at pH values around the neutral range, which, depending on the pH on the side of the ring-open hydrazones or the cyclic dihydrothiadiazoles (thiadiazolidines). The ketone derivatives of dithiocarbazic acids are known to be present as thiadiazolidine-2-thiones. In the formula scheme below, the specified derivatives of the copolymerized diacetoneacrylamide are based on the ring-open form, regardless of the equilibrium position.

The Copolymers I fall in the precipitation polymerization in high yield and purity, provided that the content of hydrophobic Monomer 10-20 mol%, based on total monomer, does not exceed. They are considered easy obtainable filterable and easy to dry powder. Especially suitable polymers contain acrylamide as a neutral comonomer (C) and acrylic acid, methacrylic acid or 2-acrylamido-2-methylpropanesulfonic acid as acid comonomers (D).

In the preparation of the copolymers I are used as polymerization initiators preferably organic peroxides used. Suitable initiators are t-butyl peroxy octoate, t-butyl peroxybenzoate, Dibenzoyl. The polymerization is carried out in the absence of atmospheric oxygen carried out, preferably in a nitrogen atmosphere.

It It is not known if the incorporation of the monomers into the rapidly growing Chain occurs statistically, but one can assume that at least in the first phase of chain growth a diffusion-controlled Consumption of the monomers takes place from the solution. By the diffusion-controlled Growth of the polymer chains will increase the uniformity of the polymers favored. About the However, uniformity of the copolymers formed is not known.

The Formation of crosslinking bridges And thus a stable particle shape can also be retrofitted by implementation a non-crosslinked or only slightly crosslinked polymer, the is present in suspended form, with a bifunctional reacting Aldehyde can be achieved, for example, by post-treatment of a non crosslinked copolymers with formaldehyde, glyoxal, glyoxylic acid, glutaraldehyde, 2,5-dimethoxytetrahydrofuran or with a formaldehyde precursor. Also the formation of crosslinks via intercatenare Amide functions is possible.

suitable crosslinked polymers are swellable in water over wide pH ranges, but not soluble due to the built in crosslinking bridges. It It can be assumed that the Polymer an ion exchanger-like Function performs and preferably with transition metal ions Chelates forms, where the thiol group, or the enolisable Thione group, either as a neutral ligand or via its conjugated anion is involved. The chelates can be formed intracatenar or intercatenar.

One high proportion of carboxyl-containing monomers in copolymer I or in the metal-binding invention Copolymer can interfere by leading to the binding of alkaline earth and earth metal ions, as a result the swelling of the polymer particles decreases and the uptake of Heavy metal ions hindered by the polymer. On the other hand can the treatment of a weakly crosslinked polymer with alkaline earth ions or aluminum ions, however, can be exploited specifically, the Crosslinking and thus the swellability of the copolymer in use adjust.

A List of purposefully assembled Copolymers I, over the molar ratios m, n, o, p, q and r of the monomers used is defined indicated below. The sum of the molar ratios m to r refers on the molar ratios the monomers used. Their sum is therefore 100 percent. The information about the Compositions of the copolymers are normative, those actually found Composition may differ slightly.

in the The following is between the copolymers of the formula I, the no carry chelating function (CP-1 to CP-18), and the resulting accessible polymeric metal complexing agents CPT containing a chelating agent Thiol or thione group are functionalized, distinguished. In the chelating polymer CPT may be the proportion of the functional Monomers maximum correspond to the numerical index m, because of the incomplete Reaction of the functionalizable comonomers with the introduction of the thiol / thione group enabled Reagent is usually a part of unchanged. This proportion will not be marked separately. According to the invention is at least one-third of the monomers (A) or (B) to a metal-binding Monomer A ', A' 'or B' reacted.

Listed below is a list of copolymers useful in the introduction of thiol / thione group containing functional groups. CP-1 to CP-15 stand for the allyl and diallyl ammonium copolymers, which after the in DE 29 44 092 A1 as in US 4,329,441 CP-16 to CP-18 for copolymers based on diacetone acrylamide.

Copolymers CP-1 to CP-7

Copolymers CP-8 to CP-15

Copolymers CP-16 to CP-18

In the above-mentioned copolymer CP-1 to CP-18 represents the symbol (id) the linkage of a second copolymer chain and thus - on the degree of crosslinking - a the Swelling controllable structural element dar. The thus suggested identity However, the monomer residues bound thereto are not inventive in nature.

• (A) Allylammoniumchlorid oder Diallylammoniumchlorid in einem molaren Anteil zwischen 20 und 50 mol-%,
• (C) Acrylamid in einem molaren Anteil zwischen 30 und 50 mol-%,
• (D) Acrylsäure oder Methacrylsäure in einem molaren Anteil zwischen 0 und 35 mol-%
• (E) Butylacrylat in einem molaren Anteil zwischen 0 und 15 mol-%, sowie
• (F) N,N-Methylen-bis-acrylamid in einem Anteil zwischen 1 und 5 mol-%.

Particularly advantageous hydrophilic polymeric complexing agents are, for example, those which have been prepared from a crosslinked copolymer of the formula I and contain the following copolymerized comonomer components:

• (A) allylammonium chloride or diallylammonium chloride in a molar fraction of between 20 and 50 mol%,
• (C) acrylamide in a molar fraction between 30 and 50 mol%,
• (D) acrylic acid or methacrylic acid in a molar proportion between 0 and 35 mol%
• (E) butyl acrylate in a molar proportion between 0 and 15 mol%, as well as
• (F) N, N-methylene-bis-acrylamide in a proportion between 1 and 5 mol%.

When Polymerization initiator in the examples either t-butyl peroxyoctoate (t-butyl peroctoate) or t-butyl peroxybenzoate (t-butyl perbenzoate) used. The used chain transfer is Diethyl phosphite, 2,5-dimercapto-1,3,4-thiadiazole or 2,2'-dimercapto-diethyl ether.

For the implementation of neutralized copolymers, the allylamine or diallylamine units as free bases, are particularly suitable as reactants the following aliphatic isothiocyanates: methyl isothiocyanate, ethyl isothiocyanate, Allyl isothiocyanate, the lower alkyl isothiocyanatoacetate, 2-isothiocyanatopyridine, the latter also in dimerized form.

When Reaction partner, the bidentatchelatbildenden in the polymer backbone thiocarbamate groups introduce are capable of acyl isothiocyanates, for example, acetyl isothiocyanate, Trimethylacetylisothiocyanate, benzoylisothiocyanate, alkoxycarbonylisothiocyanates, Alkoxy thiocarbonyl isothiocyanates, carbamoyl isothiocyanates, for example N, N-dimethylcarbamoylisothiocyanate, N, N-dimethylthiocarbamoylisothiocyanate, sulfonylisothiocyanates, e.g. Methanesulfonylisothiocyanate, benzenesulfonylisothiocyanate, N, N-dimethylsulfamoylisothiocyanate; Phosphoryl isothiocyanates, e.g. Diethoxyphosphorylisothiocyanat, Diethoxythiophosphorylisothiocyanate, diphenoxythiophosphorylisothiocyanate, 3-isothiocyanato-benzo-l, 2-thiazol-l, l-dioxide.

The reactive isothiocyanates are selected from the corresponding acyl halides, Acyl halide analogues or alkyl chloroformates or from phosphoryl halides by reaction with inorganic thiocyanates according to known methods produced. Another method of preparation is dithiocarboxylates, Dithiocarbamates, xanthates or thiophosphates with cyanogen chloride or To react cyanogen bromide. These reactions are known to lead first Formation of acyl thiocyanates under the conditions of the synthesis to the desired ones reactive isothiocyanates are rearranged.

phosphoryl and thiophosphoryl isothiocyanates are known and readily reactive heterocumulenes, add the amines in anhydrous systems and in high yields form phosphorylated thioureas. They will be different Methods are prepared, of which the implementation of the corresponding phosphoryl chlorides and thiophosphoryl chlorides with alkali metal thiocyanates, ammonium thiocyanate or lead thiocyanate in aprotic solvents the best known represents.

• Houben-Weyl; Methoden der Organischen Chemie Band 12/1,Seiten 276-286
• Houben-Weyl; Methoden der Organischen Chemie Band 12/2, Seiten 607-798
• R.M. Kamalov, M.G.Zimin und A.N. Pudovik; in Russian Chemical Reviews 54 (12) 1210-1226 [1985]: Isothiocyanates of Phosphorus Acids, N-Phosphorylated Thionocarbamates and Thioureas.

In connection with the electronegatively substituted isothiocyanates, the following literature should be regarded as representative:

• Houben-Weyl; Methods of Organic Chemistry Volume 12/1, pages 276-286
• Houben-Weyl; Methods of Organic Chemistry Volume 12/2, pages 607-798
• RM Kamalov, MGZimin and AN Pudovik; in Russian Chemical Reviews 54 (12) 1210-1226 [1985]: Isothiocyanates of Phosphorus Acids, N-Phosphorylated Thionocarbamates and Thioureas.

Important Data and notes on syntheses and reactions can also be found in reviews, e.g. at

• V. Sharma in Sulfur Reports 8, (5) 327-470 [1989] and
• J. Goerdeler in Quart. Rep. Sulfur Chem. 5 (3) [1970], 169-175.
• J. Michalski; Liebigs Ann. Chem. [1977] 6, 924,
• Roczniki Chem. 31, 585 [1957] and in DBP 952,085, 1,067,017, The 1,129,953.

Information about the Complex-chemical properties of the acylthioureas can be found among others in

• Nachr.Chem.Techn.Lab. 40, No. 6, 682-691 and at
• L. Beyer, E.Hoyer; Z.Chem. 21, 3, 81-91.

information for the complex formation of phosphorylated thioureas with transition metals especially found

• M. G. Zimin, R.M. Kamalov, R.A. Cherkasov and A.N. Pudovik in Phosphorus & Sulfur 13, 371 [1982].

Instead of the free isothiocyanates can also reactive precursors thereof are used, for example S-alkyldithiocarbamates, O-aryl carbamates or cyclized dimers consisting of highly electrophilic Isothiocyanates by longer Standing are formed and give again isothiocyanates when heated.

The Reaction of amino groups with sufficiently electrophilic isothiocyanates extends generally in high yield unless the polymer backbone is is too high crosslinked to allow the reaction with the isothiocyanate. Problems can result from the fact that at unselective reaction also carboxyl groups in the corresponding copolymers for the reaction come. This reaction can be used to build up carbamide groups or crosslinks to lead.

For the implementation of copolymerized allylamine or diallylamine monomer units Activated esters in the form of thiolactones from 4-mercaptoalkanecarboxylic acids, for Example, the homocysteine thiolactone.

Links, the for the introduction a remainder = N-T ', or a cyclized equivalent, in polymers with diacetoneacrylamide units B are found in the series of mercaptocarboxylic acid hydrazides, thiosemicarbazides, the dithiocarbazate, the heterocyclic N-aminothiones from the Rows of N-aminotriazoline thiones, N-aminoimidazoline thiones, and N-aminothiohydantoins.

For the reaction of copolymers I with Diacetonacrylamideinheiten B are particularly suitable the following derivatives of thiosemicarbazide as reactants: 2-methylthiosemicarbazide, 4-methylthiosemicarbazide, 4-allylthiosemicarbazide, 4,4-dimethylthiosemicarbazide, 4-trimethylacetylthiosemicarbazide,
4-Diethoxyphosphorylthiosemicarbazide, 4-Diethoxythiophosphorylthiosemicarbazid, the alkali metal or ammonium salts of dithiocarbazic acid and 1-methyldithiocarbazic acid.

suitable N-amino-azolin-thiones are 1-amino-5,5-dimethyl-2-thiohydantoin, 4-amino-3-mercapto-1,2,4-triazole, 4-amino-3-methyl-5-mercapto-1,2,4-triazole, 4-amino-3,5-dimercapto-1,2,4-triazole, 4-Amino-3-hydroxy-5-mercapto-1,2,4-triazole, 3,4-diamino-5-mercapto-1,2,4-triazole and N-aminorhodanine.

As well are suitable for it Thioglykolsäurehydrazid, 2,3-Dimercaptopropionsäurehydrazid and homocysteine hydrazide, which is particularly easy from the thiolactone accessible is. Also in the 2-mercaptoalkylcarboxylic acid hydrazides is an equilibrium between cyclized and ring open form into consideration.

at the derivatives of dithiocarbazinic remains with the implementation a carbonyl function is not known at the stage of the hydrazone stand, there arise 1,3,4-Thiadiazolidin-2-thiones, the ring by formation of a Heavy metal chelates slightly open becomes.

Chelatbildende Thioharnstoffpartialstrukturen:

A list of complexing or chelating thiourea partial structures according to the invention, thiosemicarbazone groups, acylhydrazone groups and amide groups can be found in the following: Chelating thiocarbazate and thiosemicarbazone partial structures:

Chelating thiourea partial structures:

Chelating mercaptoacylhydrazone and mercaptoamide partial structures:

Especially favorable Structures are of the acid hydrazides the mercaptoalkanecarboxylic acids derived, in turn, made of thiolactones particularly simple can be.

4.3. Advantages of the invention

One particular advantage of the invention is that the copolymers of the invention higher in comparison to biosorbents Can absorb quantities of metal and a stronger one Allow lowering of the metal load. Thus eliminates the Dealing with sorbents in large Volumes and the need for large plant and landfill volumes provide. Also the recovery economically interesting metal components from the loaded polymers is so relieved.

Moreover, selection of the thiol / thion ligands, particularly the thiocarbamate ligands, can provide selective extraction capability and minimize susceptibility to alkaline earth, aluminum, zinc or iron disturbances. Furthermore, the copolymers according to the invention can be optimally adapted to the entire process, including the isolation of the metal-loaded polymer, by the chosen monomer composition. A further advantage results from the fact that the sorption agent according to the invention regenerates, for example by treatment with the aqueous solution of a SH-containing water-soluble low-molecular complexing agent (eg Na ₂ S ₂ O ₃ , (NH ₄ ) ₂ S ₂ O ₃ , NH ₄ SCN , KSCN), and so can be used repeatedly.

5. Manufacturing and application examples:

5.1. Production of master polymers according to the invention.

below will be the production and modification of a number of representative Copolymers by incorporation of a Thiocarbamatgruppe T described.

The Starting materials allylammonium chloride and diallylammonium chloride become commonplace Prepared by treating the free amines with hydrogen chloride, preferably under conditions in which the hydrochlorides crystallize out and can be taken without binding of water.

t-butanol is, unless otherwise stated, with an addition of 10% chlorobenzene used. The duration of the polymerization after the end of the monomer addition is, Unless otherwise stated, 4 hours.

Example 1 Allylamine Copolymers CP-1 to CP-3 (containing carboxyl groups, crosslinked)

CP-1:

you puts 200 ml of t-butanol under nitrogen in a four-necked flask, heated to reflux and hold for 15 minutes boiling.

0.3 ml of t-butyl peroctoate in 5 ml of oxygen-free t-butanol (initiator solution) are added to the boiling mixture, and a monomer solution prepared under nitrogen is added dropwise within 60 minutes with stirring
34.8 g (0.49 mol) of acrylamide,
23.3 g (0.25 mol) of allylammonium chloride,
18.0 g (0.25 mol) of acrylic acid,
1.54 g (0.01 mol) of methylene-bis-acrylamide and
2.30 g of diethyl phosphite in
300 ml of t-butanol too.

To 10 to 15 minutes sets the deposition of the polymer as a white powder one.

Another 5 ml of initiator solution are added after complete addition of the monomers. The mixture is stirred under reflux and cooled to room temperature. The precipitated copolymer is suctioned off on a suction filter, washed with isopropanol and dried in vacuo.
Yield: 63 g = 81% d. theory

CP-2 and CP-3

• are prepared analogously, but with the difference: that in the comonomer mixture instead of acrylic acid the equivalent Amounts (0.25 mol) of methacrylic acid, or itaconic acid be used.

Example 2:

CP-4 to CP-6 (diallylamine copolymer containing carboxyl groups, crosslinked)

you moves as in Example 1, but with the difference that the comonomer composition follows and the amount of diethyl phosphite is increased:

CP-4:

• 34.8 g of acrylamide (0.49 mol),
• 34.0 g of diallylammonium chloride (0.25 mol),
• 18.0 g of acrylic acid Rod. (0.25 mol),
• 1.54 g of methylenebis-acrylamide (0.01 mol) and
• 2.8 g of diethyl phosphite in
• 400 ml of t-butanol
• Yield: 65g white, Swellable in water but insoluble Powder (73.6% of theory)

The Cl determination (8.5% Cl) shows that the diallylammonium chloride is incorporated in the copolymer to 85%

CP-5:

• 34.8 g of acrylamide (0.49 mol),
• 34.0 g of diallylammonium chloride (0.25 mol),
• 18.0 g of acrylic acid Rod. (0.25 mol),
• 3.08 g of methylenebis-acrylamide (0.02 mol) and
• 2.8 g of diethyl phosphite in
• 400 ml of t-butanol

CP-6:

• 34.8 g of acrylamide (0.49 mol),
• 34.0 g of diallylammonium chloride (0.25 mol),
• 18.0 g of acrylic acid Rod. (0.25 mol),
• 6.15 g of methylenebis-acrylamide (0.04 mol) and
• 2.8 g of diethyl phosphite in
• 400 ml of t-butanol

Example 3:

CP-7 (amphoteric allylamine copolymer containing sulfonate groups, crosslinked)

you moves as in Example 1, but with the difference that the comonomer composition follows is set.

• 23.45 g (0.33 mol) of acrylamide,
• 18.8 g (0.33 mol) allylamine,
• 68.3 g (0.33 mol) of 2-acrylamido-2-methylpropanesulfonic acid,
• 1.54 g (0.01 mol) of methylenebis-acrylamide and
• 2.30 g diethyl phosphite
• 500 ml of t-butanol
• Yield: 80.6 g water-insoluble powdery Polymer (72.6% of theory)

Example 4:

CP-8 and CP-9:

you moves as in Example 1, but with the difference that the comonomer composition follows is set. The stirring time under reflux is 6 hours.

CP-8:

• 27.0 g (0.38 mol) of acrylamide,
• 12.7 g (0.10 mol) of N-t-butylacrylamide,
• 46.75 g (0.50 mol) of allylammonium chloride,
• 3.08 g (0.02 mol) of methylenebis-acrylamide and
• 2.30 g diethyl phosphite
• 500 ml of t-butanol
• Yield: 56.8 g of water-insoluble powdery Polymer (63% of theory)

The Cl determination (16.91% Cl) shows that the allylammonium chloride is incorporated in the copolymer to 85%.

CP-9:

• 27.0 g (0.38 mol) of acrylamide,
• 12.7 g (0.10 mol) of N-t-butylacrylamide,
• 67.25 g (0.50 mol) of diallylammonium chloride,
• 3.08 g (0.02 mol) of methylenebis-acrylamide and
• 2.30 g diethyl phosphite
• 500 ml of t-butanol
• Yield: 59 g of water-insoluble powdery Polymer (54% of theory)
• The Cl determination (13.2% Cl) shows that the allylammonium chloride 82% incorporated in the copolymer.

Example 5:

CP-10

• is produced analogously to CP-8, but with the difference that instead of diethyl phosphite 1.5 g of 2,2'-dimercapto-diethyl ether be used as a co-initiator. Yield 70 g of powdered polymer.

CP-11

• is produced analogously to CP-8, but with the difference that instead of diethyl phosphite 1.2 g of 2,5-dimercapto-1,3,4-thiadiazole as co-initiator be used. Yield 65 g of powdered polymer.

Example 6:

CP-12, CP-13 (carboxyl group-containing Diallylammonium copolymers, crosslinked)

CP-12: (low networked)

• is produced analogously to CP-3, but with the difference that this monomer ratio as follows: Acrylamide 39.5 mol%, diallyl 40 mol%, itaconic 10 mol%, Butyl acrylate 10 mol%, N, N'-methylenebis-acrylamide 0.5 mol%.
• Yield: 65 g water-insoluble powdery Polymer. The polymer swells very strongly in water.

CP-13

• is prepared by adding a suspension of 50 g CP-12 in 200 ml of chlorobenzene is boiled under reflux for 3 hours. The obtained Copolymer is filtered off with suction, stirred with isopropanol, again filtered off with suction and im Vacuum dried. The polymer shows in water towards CP-12 strongly reduced swelling power, attributed to a networking over Carbonamidbindungen.

example 6 shows that the inventive method precipitation polymers results, whose swellability are strongly influenced by the cross-linking can.

Example 7:

CP-14 (amphoteric diallyl ammonium copolymer, ) Links:

• is prepared by copolymerization analogous to the amphoteric copolymer CP-7 prepared, but with the difference that the amount of solvent doubled is used and the following monomers in the molar ratio given below become: Diallylamine 48 mol%, 2-acrylamido-2-methylpropanesulfonic acid 48 mol%, ethylene glycol 4 mol%.

The Copolymer shows low swelling capacity in water.

Example 8:

CP-15 (cationic diallyl ammonium copolymer, ) Links:

The procedure is as in Example 4, CP-9, but with the difference that the diallyl ammonium chloride is added to the template and the comonomer mixture is composed as follows. Solution A: 53.4 g of diallylammonium chloride (0.40 mol) 2.8 g of diethyl phosphite (0.02 mol) in 300 ml of t-butanol Solution B: 27.0 g acrylamide (0.38 mol) 12.7 g t-butylacrylamide (0.10 mol) 3.02 g methylenebis-acrylamide (0.02 mol) 200 ml t-butanol Solution C: 0.6 ml t-butyl peroctoate 60 ml t-butanol

From solution C will be half added as soon as the template (solution A) has come to a boil, immediately after solution B in 30 minutes added, the addition of the second half of solution C takes place as soon as the Addition of solution B is finished. The stirring time is 3 hours.

• Yield 70g (73% of theory)
• Cl (found) 12.6%;
• Cl (calculated) 14.8%

Example 9:

Copolymers CP-16 to CP-18

The procedure is as in Example 1, wherein the starting monomer mixture is composed as follows. The addition of diethyl phosphite as co-initiator can be omitted. The stirring time is 2 hours. CP-16: 74 mol% acrylamide 25 mol% diacetone acrylamide 1 mol% methylenebis-acrylamide CP-17: 48 mol% acrylamide 25 mol% acrylic acid 25 mol% diacetone acrylamide 2 mol% methylenebis-acrylamide CP-18: 48 mol% acrylamide 10 mol% 2-acrylamido-2-methylpropanesulfonic acid (Na salt) 40 mol% diacetone acrylamide 2 mol% methylenebis-acrylamide

5.2. Preparation of thiocarbamate-modified according to the invention copolymers

CPT-1: thiourea-modified crosslinked allylamine copolymer (containing carboxyl groups)

50 g of allylammonium copolymer CP-2 are suspended in 400 ml of methanol, 12 ml of triethylamine are added dropwise, the mixture is taken up in 400 ml of acetonitrile, heated to reflux with stirring, and a solution of 7.5 g of methyl isothiocyanate (0.1 mol) is added 50 ml of acetonitrile too. The mixture is refluxed for 3 hours, cooled to room temperature, 100 ml of methanol and filtered off with suction. It is washed twice with 100 ml of methanol and dried in vacuo at 45 ° C. This gives 53.2 g of a water-swellable, but not water-soluble powder.
Analysis: S _calculated : 4.86%, S _found : 3.90%

CPT-2: thiourea-modified crosslinked diallylamine copolymer (containing carboxyl groups)

• is obtained analogously to CPT-1, but with the following differences: 40 g of diallylammonium copolymer CP-4 are used. The amounts of triethylamine and methyl isothiocyanate: 7.5 g of triethylamine, 5.0 g of methyl isothiocyanate (excess).

you receives 45 g of a white, swellable, but insoluble in water Copolymers.

Acylthioharnstoffmodifizierte Diallylamine copolymers (crosslinked, carboxyl group-free)

CPT-3:

you suspended with stirring 51.3 g of allylammonium copolymer CP-7 (crosslinked, carboxyl group-free) in 200 ml of acetonitrile, 20.2 g of triethylamine (0.2 mol), heated with stirring to reflux and dripping a freshly prepared solution of ethoxycarbonyl isothiocyanate in 150 ml of acetonitrile. It lasts 2 hours under reflux, cool 40-45 ° C, Add 100ml of methanol, cool to room temperature and sucks on a suction filter. You wash with 100 ml of methanol and dried in vacuo at 40 ° C. This gives 60 g a white, in Water suspendible powder which swells on treatment with dilute ammonia solution, but not soluble becomes.

CPT-4:

The experiment is repeated, but with the difference that a fresh from 24.9 g of benzoyl chloride and 15.2 g of ammonium thiocyanate (= 0.2 mol each) in 200 ml of acetone by stirring for 1 hour and suction of precipitated salt (NH ₄ Cl) prepared solution of benzoyl isothiocyanate is used. This gives 54 g of a yellowish, suspendable in water under acid reaction insoluble polymers.

CPT-5: thiobiuret-modified crosslinked diallylamine copolymer (carboxyl group-free)

you Prepared from Dimethylthiocarbamidchlorid and Ammoniumrhodanid in Acetonitrile at 10-20 ° C a solution of 0.1 mol Dimethylthiocarbamoylisothiocyanat, sucks of excreted Salt and the filtrate is added dropwise to a suspension of 5O, 5g of the carboxyl-containing diallyl ammonium copolymers CP-6 and 15 ml of triethylamine in 300 ml of acetonitrile. 10 ml of triethylamine are added after, stir 3 hours at 45-50 ° C, cools down Room temperature and sucks on a suction filter. You wash that Mixture twice with 200 ml of methanol and dried at 40 ° C in vacuo. You get a pale yellow Powder which can be suspended in water under a weakly acidic reaction is.

CPT-6: phosphorylthiourea-modified Allylamine copolymer (crosslinked, containing carboxyl groups)

you prepared from 9.0 g of diethoxyphosphoryl chloride and 3.9 g of ammonium thiocyanate in 80 ml of tetrahydrofuran a solution of 0.05 moles of diethoxyphosphoryl isothiocyanate (information A. Lopusinski, M. Michalski and W.J. Stec; Liebigs Ann.Chem.l977, 924-947), sucks Of precipitated salts and gives the solution at 5-10 ° C to a with 15 ml triethylamine neutralized suspension of 25 g CP-6 in 150 ml of acetonitrile. After the decay of the exothermic reaction The suspension is heated for 2 hours on reflux and allowed to cool overnight. It sucks on a suction filter, the polymer is washed with methanol and dried in vacuo. You get an odorless powder that is in water under neutral reaction is suspendable.

CPT-7: Thiophosphoryl thiourea modified Allylamine copolymer (crosslinked, containing carboxyl groups)

The Preparation of CPT-6 from CP-6 is performed with a solution of 0.05 moles of diethoxyphosphoryl isothiocyanate repeated, from equimolar Amounts of Na diethyl dithiophosphate and cyanogen chloride in dichloromethane / acetonitrile. The The suspension obtained is heated with stirring for 4 hours at reflux. you sucks over after standing Night on a nutsche, washes the polymer twice with 50 ml of methanol and dried in vacuo. You get 28g of a yellowish powder.

CPT-8: dithiocarbamate modified Allylamine copolymer (crosslinked, carboxyl group-free)

28.5 g CP-7 are suspended in 100 ml of methanol. With stirring, 2.5 g KOH to the suspension, stirring 15 minutes, the polymer sucks, washed with 50 ml of water and 50 ml of methanol, redispersed in 100 ml of isopropanol, gives 9 ml of carbon disulfide and drips a solution of 2.8 g of KOH in 75 ml of methanol. The yellow-colored suspension is 1 hour touched, filtered off with suction and washed with methanol. The polymer shows in water alkaline reaction, but does not dissolve.

CPT-9:

you 35 g copolymer CP-7 (crosslinked amphoteric copolymer) suspended in 150 ml of acetonitrile and are successively 12 ml of triethylamine and 13 g of freshly distilled ethoxycarbonylisothiocyanate. It is stirred for 1 hour at 50-60 ° C, lets cool, sucks, washes with methanol and dried in vacuo. This gives 38 g of thiourea-modified Polymer in the form of a white water Powder.

CPT-10:

• is obtained analogously to CPT-1, but with the following differences: 20 g of diallyl ammonium copolymer CP-14 are used and stir with an excess of triethylamine neutralized. The resulting copolymer is dissolved in 150 ml of acetonitrile with an excess of allyl isothiocyanate cooked for two hours, after cooling filtered off with suction to room temperature, washed with methanol and dried.

you receives 23 g of a white, insoluble in water Copolymers whose swellability compared to the Output polymer slightly elevated is.

5.3. Application examples: Metal extraction with thiocarbamate modified according to the invention copolymers:

Example A:

Removal of dissolved copper from aqueous solution (25 mg CuSO ₄ × 5H ₂ O = 0.10 mmol per 1000 ml):
2 g of one of the following copolymers are stirred into each 1000 ml of copper sulfate solution. After 5 minutes, the solution is filtered off with suction through a glass frit and the respective copper content is determined.

• CPT-1 (per 2g / 1000ml solution 1)
• CPT-2 (2g / 1000ml solution each 2)
• CPT-3 (2g / 1000ml solution each 3)

The residual content of Cu is for
Solution 1: 0.1 mg Cu / 1000 ml
Solution 2: <0.05 mg Cu1000 ml
Solution 3: 0.14 mg Cu / 1000 ml
ie the dissolved copper is removed by more than 90%

Example B:

distance of solved Cadmium from aqueous solution:

6000 ml of cadmium sulfate solution containing 5 mg of CdSO ₄ = 0.024 mmol / 1000 ml are prepared, divided into 3 parts of 2000 ml each, adjusted in each case with buffer solution to pH = 2, pH = 4 and pH = 6 and halved. 1 g of thiocarbamate-modified copolymer are stirred into 1000 ml each of cadmium sulfate solution.
Solutions 4 / 1-3: CPT-5 (1mg cd / 1000ml each)
Solutions 5 / 1-3: CPT-8 (1mg cd / 1000ml each)

After 25 minutes of standing time, the solution is filtered off with suction through a glass frit and the cadmium content is determined. He is for Solution 4/1: pH = 2 0.051 mg Cd / 1000 ml Solution 4/2: pH = 4 0.027 mg Cd / 1000 ml Solution 4/3: pH = 6 0.027 mg Cd / 1000 ml Solution 5/1: pH = 2 0.05 mg Cd / 1000 ml Solution 5/2: pH = 4 0.011 mg Cd / 1000 ml Solution 5/3: pH = 6 0.022 mg Cd / 1000 ml

The dissolved Cadmium is thus removed by more than 95%.

Example C:

distance of solved Arsenic trioxide from aqueous solution

6000 ml of a prepared As ₂ O ₃ solution containing 2 mg of As ₂ O ₃ = 0.0101 mmol / 1000 ml are divided into three parts of 2000 ml each and adjusted with buffer solutions to pH = 2, pH = 4, pH = 6 is set. Of these, a total of 6 solutions of 1000 ml each are prepared by halving.

In 1000 ml each of arsenic solution are stirred per 1 g thiocarbamate-modified copolymer.

• solutions 6 / 1-3: CPT-5 (per 1g / 1000ml solution)
• solutions 7 / 1-3: CPT-7 (per lg / 1000ml solution)

Of the pH of the solutions 6/2, 6/3, 7/2 and 7/3 are readjusted with 0.01m buffer solution. The resulting Suspensions are stirred by blowing in air. After an hour will be the solutions each over vacuumed a glass frit. The remaining arsenic content is determined by ICP-MS determined.

He is for Solution 6/1: pH = 2 0.018 mg As / 1000 ml Solution 6/2: pH = 4 0.005 mg As / 1000 ml Solution 6/3: pH = 6 0.015 mg As / 1000 ml Solution 7/1: pH = 2 0.025 mg As / 1000 ml Solution 7/2: pH = 4 <0.005 mg As / 1000 ml Solution 7/3: pH = 6 <0.01 mg As / 1000 ml

The means it with the polymers according to the invention possible is, in a simple operation arsenbelastetes water up drinking water quality (WHO standard <0.01 mg As / 1000 ml).

Example D:

Removal of dissolved mercury (II) acetate (MM 318.7) from aqueous solution In each 1000 ml of mercuric acetate solution with a content of 2 mg = 0.00627 mmol / 1000 ml) are stirred per 2 g thiocarbamatmodifiziertes copolymer.
Solution 8: CPT-2 (2g / 1000ml each)
Solution 9: CPT-3 (2g / 1000ml each)
Solution 10: CPT-9 (2g / 1000ml each)

After 15 minutes of standing time, the solutions are filtered off with suction through a glass frit and the respective mercury content is determined. He is for
Solution 8: 0.14 mg Hg / 1000 ml
Solution 9: 0.08 mg Hg / 1000 ml
Solution 10: 0.11 mg Hg / 1000 ml
ie the dissolved mercury is removed by more than 90%.

Claims (12)

Process for the removal of dissolved heavy metals, transition metals and / or semimetals from aqueous solutions, characterized in that the solution is temporarily contacted with a particulate water-insoluble hydrophilic polymeric complexing agent comprising recurring metal complex-forming structural units of at least one of the formulas (A '), (A '') and (B ') and has crosslinking bridges,

wherein the radicals R, T and T 'have the following meaning: R: H or an optionally substituted alkyl radical; T: an optionally connected via an electrophilic link with N rest with at least one capable of forming metal chelates thiol or thione group; T ': a thiocarbamate group, a heterocyclic radical preferably bonded via an N atom with at least one thiol or thione group capable of forming metal chelates, or an alkyl or arylcarbonamide group substituted by at least one thiol group. Process according to Claim 1, characterized in that the water-insoluble hydrophilic polymeric complexing agent present in particulate form comprises, in addition to further copolymerized monomers, at least 5 mol% of recurring metal complex-forming structural units of at least one of the formulas (A '), (A'') and (B'), and contains at least 0.5 mol% of a copolymerized monomer which provides crosslinking bridges,

wherein the radicals R, T and T 'have the following meaning: R: H or an optionally substituted alkyl radical; T: an optionally connected via an electrophilic link with N rest with at least one capable of forming metal chelates thiol or thione group; T ': a thiocarbamate group, a heterocyclic radical preferably bonded via an N atom with at least one thiol or thione group capable of forming metal chelates, or an alkyl or arylcarbonamide group substituted by at least one thiol group. A method according to claim 1, characterized in that the water-insoluble hydrophilic polymeric complexing agent has been prepared from a water-insoluble hydrophilic copolymer of the formula I, - (A) _m - (B) _n - (C) _o - (D) _P - (E) _q - (F) _r -I wherein (A), (B), (C), (D), (E) and (F) denote copolymerized monomers, and m, n, o, p, q and r denote the relative proportion of the monomers on the copolymer in molar Percent, according to the following definition: A: allylamine, a monosubstituted allylamine or diallylamine, in free form or in the form of a salt; B: diacetone acrylamide; C: acrylamide, methacrylamide, 2-hydroxyethyl acrylate; D: acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, methacryloyloxyethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, in free form or in salt form; E: an ester of acrylic, methacrylic, maleic or itaconic acid, N-tert-butylacrylamide, styrene, N-vinylpyrrolidone, N-vinylcaprolactam; F: a monomer which provides crosslinkers; m, n: each 0 - 69.5 mol%, with the proviso that m + n ≥ 15 mol%, and that m ≥ 10 mol%, when n ≤ 10 mol%; o: 0 - 80 mol%, p: 0 - 50 mol%, with the proviso that o + p ≥30 mol%; q: 0 - SO mol%; r: 0.5-10 mol%, wherein at least one third of the copolymerized monomers (A) and (B) has been converted to the corresponding metal-binding monomers of the formulas (A '), (A ") or (B') .

wherein the radicals R, T and T 'have the following meaning: R: H or an optionally substituted alkyl radical; T: an optionally connected via an electrophilic link with N rest with at least one capable of forming metal chelates thiol or thione group; T ': a thiocarbamate group, a heterocyclic radical preferably bonded via an N atom with at least one thiol or thione group capable of forming metal chelates, or one having at least one Thiol group substituted alkyl or arylcarbonamide group. Method according to one of claims 1 to 3, characterized in that the the water-insoluble hydrophilic polymeric complexing agent underlying copolymer I from a Comonomer mixture containing 0.5-10 mol% hydroxymethylacrylamide, Methoxymethylacrylamide, hydroxymethylmethacrylamide, methoxymethylmethacrylamide or methylene-bis-acrylamide as a crosslinking-bridging comonomer. Hydrophilic polymeric complexing agent in the form of finely divided filterable and by crosslinking water-insoluble particles, characterized by the formula I, - (A) _m - (B) _n - (C) _o - (D) _p - (E) _q - (F) _r -I wherein (a), (B), (C), (D), (E) and (F) copolymerized monomers, and m, n, o, p, q and r the relative proportion of the monomer to the copolymer in mol percent according to the following definition: A: allylamine, a monosubstituted allylamine, or diallylamine, in free form or in the form of a salt; B: diacetone acrylamide; C: acrylamide, methacrylamide, 2-hydroxyethyl acrylate; D: acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, methacryloyloxyethanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidomethanesulfonic acid, acrylamidomethanephosphonic acid, optionally monounsaturated, and N-acryloyltaurine in free form or in salt form: E: an ester of acrylic -, methacrylic, maleic or itaconic acid, N-tert-butylacrylamide, styrene, N-vinylpyrrolidone, N-vinylcaprolactam; F: a bifunctional, trifunctional or tetrafunctional monomer from the series of acrylamides, methacrylamides, acrylic esters, methacrylic esters; m, n: each 0 - 69.5 mol%, with the proviso that m + n ≥ 15 mol%, and that m ≥ 10 mol%, when n ≤ 10 mol%; o: 0 - 80 mol%, p: 0 - 50 mol%, with the proviso that o + p ≥30 mol%; q: 0-50 mol%; r: 0.5-10 mol%, wherein at least one third of the copolymerized monomers (A) and (B) has been converted to the corresponding metal-binding monomers of the formulas (A '), (A ") or (B') .

wherein the radicals R, T and T 'have the following meaning: R: H or an optionally substituted alkyl radical; T: an optionally connected via an electrophilic link with N rest with at least one capable of forming metal chelates thiol or thione group; T ': a thiocarbamate group, a heterocyclic radical preferably bonded via an N atom with at least one thiol or thione group capable of forming metal chelates, or an alkyl or arylcarbonamide group substituted by at least one thiol group. A hydrophilic polymeric complexing agent as claimed in claim 5, characterized in that it is prepared from a crosslinked copolymer of formula I and contains the following copolymerized comonomers: (A) allylammonium chloride or diallylammonium chloride in a molar fraction of between 20 and 50 mol%, (C) acrylamide in a molar fraction between 30 and 50 mol%, (D) acrylic acid or methacrylic acid in a molar fraction between 0 and 35 mol% (E) butyl acrylate in a molar proportion between 0 and 15 mol%, and (F) N, N-methylene-bis-acrylamide in an amount between 1 and 5 mol%. A hydrophilic polymeric complexing agent according to any one of claims 5 and 6, characterized in that the free amino groups of the underlying copolymer of the formula I at least one third with an aliphatic isothiocyanate have been converted to thiourea groups. A hydrophilic polymeric complexing agent according to any one of claims 5 and 6, characterized in that the free amino groups of the underlying copolymer of the formula I at least one third with a lower acyl or alkoxycarbonyl isothiocyanate, which contains not more than 7 carbon atoms, to thiourea groups have been implemented. A hydrophilic polymeric complexing agent according to any one of claims 5 and 6, characterized in that the free amino groups of the underlying copolymer of the formula I at least one-third with a lower alkoxythiocarbonyl or dialkylcarbamoyl isothiocyanate containing not more than 8 carbon atoms contains have been converted to thiourea groups. A hydrophilic polymeric complexing agent according to any one of claims 5 and 6, characterized in that the free amino groups of the underlying copolymer of the formula I at least one-third with methanesulfonyl isothiocyanate or a lower Dialkylphosphorylisothiocyanat, which is no longer contains 7 C atoms, have been converted to thiourea groups. Hydrophilic polymeric complexing agent according to claim 5 in that the metal complex-forming group by reaction of the keto group the molar proportion of diacetone acrylamide (comonomer B) of the copolymer of the formula I with an open-chain or cyclic hydrazine derivative which is a free N-amino group and at least one Thiol or thione group capable of forming metal chelates contains. Hydrophilic polymeric complexing agent according to claim 2 in that the metal complex-forming group by reaction of the keto group the molar proportion of diacetone acrylamide (comonomer B) of the copolymer of the formula I with an open-chain or cyclic hydrazine derivative which is a free N-amino group and in the vicinity to a heterocyclic thiol or thione group capable of forming metal chelates contains.