DE3004121A1 - METHOD FOR CHEMICAL CLEANING OF WATER CONTAINING SOLVED ORGANIC IMPURITIES - Google Patents

Description

DR. STEPHAN G. BESZIDIS PATENT ADVOCATE

AUTHORIZED REPRESENTATIVE AT THE EUROPEAN PATENT OFFICE

PROFESSIONAL REPRESENTATIVE ALSO BEFORE THE EUROPEAN PATENT OFFICE

DACHAU NEAR MÖNCHEN

BOX 1168

MDNCHENER STRASSE 8OA

Federal Republic of Germany

TELEPHONE: OACHAU 4371 Postal checking account Munich (BLZ 700 IOD 80)

Account no. 1 368 71

Bank account no. 806 370 at the Kreli and city

»Perkesse Dachau-Indsrsdorf (BLZ 700 515 M)

(VIA Bayerlache Ltndestwik

Girozentrale, Munich)

p 1 299

description

for patent application

TATABANYAI SCENBANYAK

Tatabanya, Hungary

concerning

Process for the chemical purification of wastewater that also contains dissolved organic contaminants

The invention relates to a method for chemical cleaning of also containing dissolved organic contaminants Sewage.

In the beginning, lime or acidic hydrolyzing metal salts were used for the chemical purification of wastewater

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their combinations applied. With the development of technical or industrial organic In chemistry, organic polyelectrolytes have come to the fore in the last few decades. The synthetic Polyelectrolytes are high molecular weight organic compounds with molecular weights of 100,000 to 10,000,000 with anionic, cationic or non-ionic functional groups.

Lately there have been numerous processes in which various sewage chemicals are used to treat wastewater are known. According to US Pat. No. 5,171,8O5, for example, polyelectrolytes are on Acrylamide base with molecular weights above 10,000 is added to the wastewater and the sludge formed is placed in settling devices separated from the purified water.

In British patent 1 092 628, ligninsulphonic acid, a high molecular weight, is used to treat the waste water organic compound of natural origin is used. The specially produced lignosulfonic acid is used for the added to wastewaters adjusted to an acidic pH value and the sludge obtained is separated off in a flotation device.

The known chemical wastewater treatment processes have the following disadvantages:

a) They are primarily only suitable for removing suspended matter. The dissolved impurities are only removed to a small extent even when using high molecular weight polyelectrolytes.

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"b) The use of the high molecular weight organic polyelectrolytes is very expensive.

c) When using lignosulfonic acid, the provision is essential for stable operations The necessary constant quality of the lignosulfonic acid is problematic. The cleaned Water is still heavily contaminated and there is a high operating cost.

The invention is based on the object of eliminating the disadvantages of conventional wastewater purification processes a process for chemical purification of wastewater that also contains dissolved organic contaminants included, which is a good with simple feasibility and low investment and operating costs Clarified water of constant quality and an easily drainable water which is advantageous in agriculture usable sludge with a high percentage of organic matter results.

The above has surprisingly been achieved by the invention.

The invention is based on the surprising finding that the electronegative groups of the alkali humates (Hydroxy groups [- OH] and carboxyl groups [- COOH]) in the alkaline medium on the electropositive groups the impurities are oriented and by hydrogen bridging and van der Waals' forces these macromolecules, which besides water of hydration are still Containing fats and dissolved impurities as inclusions, form.

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When shifting the pH value into the acidic area or when adding salts of 2 and / or 3 valent Metals are made up of the electropositive groups (Ajnino-

groups [- N - H and - NHp]) of the impurities protons bound, as a result of which stable bonds are formed and that from humic acid and impurities as well as possibly Macromolecule consisting of metal ions is precipitated.

The invention therefore relates to a process for the chemical purification of wastewater, which also contains dissolved organic impurities, by adding acids or metal salts to them and separating the resulting precipitate, preferably by gravity, optionally with subsequent conditioning and filtering of the same, and discharging the purified water, which is characterized in that first Λ or more 1 or more alkali humate (s) containing material (s) is or are added to the waste water and optionally stirred with them and then as acid (s) or metal salt (s) 1 or more mineral acid (η) and / or salt (s) of divalent and / or trivalent metals is or will be added.

The humates, the salts of humic acid, are obtained from the alkaline digestion of peat, lignite and lignite. As salts of a weak acid and a strong base, they are subject to an alkaline solution in aqueous solution Solution resulting hydrolysis. When the alkaline solution is acidified, the humic acid, which is insoluble in water, falls the end.

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Humic acid is a hydroxyphenyl, carboxyl, hydroxy, Amino, quinone, hydroquinone, keto and ether groups having compound of colloid molecular size. The elemental analysis shows an average of 54 wt. -96 C, 37 wt% 0.4 wt% N and 5 wt% H. The molecular weight of humic acid also depends to a large extent on the raw material used for its production, the production method, the pH of the precipitation and the storage time. Humic acid with a particularly high molecular weight can be obtained from coal of the Eocene period if, after the alkaline digestion, precipitation is at a low level pH is made. The molecular weight is for example that of humic acid precipitated at pH 4 3 times as large as that precipitated at a pH of 6.5. By adding electrolytes, protein or fats, the apparent molecular weight increases the humic acid to 15 to 30 times. So has humic acid with a molecular weight obtained from coal of the Eocene period and precipitated at a pH value of 6.5 of 5,000 after addition of a 0.2 M saline solution a molecular weight of 75,000 [for humic acid see also The Merck Index, 9th Ed. 4-630].

The humic acid produced from coal is used for a wide variety of purposes, for example in medicine, in agriculture and technology or industry, but so far it has not been used used for wastewater treatment.

Advantageously, the alkali humate (s) used is or are potassium humate and / or sodium humate. It is preferred to use the alkali humate or the alkali humates in amounts of 0.2 to 2.0 kg per no

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Use wastewater.

Peat cell adhesive becomes "or are used as mineral acid (s) Sulfuric acid, hydrochloric acid and / or phosphoric acid used. It is preferred to use the mineral acid (s) in such an amount that the pH is adjusted to below 4 × will.

Aluminum sulfate, iron (II) sulfate and / or iron (III) chloride is or are advantageously used as salt (s) of divalent and / or trivalent metals. It is preferred to use the salt or the salts of divalent and / or trivalent metals in amounts of 0.2 to 2.0 kg, in particular 0.2 to 1.2 kg, per jsP of wastewater.

The sludge formed can in a manner known per se, depending on the specific weight of the impurities, expediently by flotation.

According to a preferred embodiment of the invention When the sludge is separated by flotation, the process takes place simultaneously with the formation of the flakes Air is introduced into the water and optionally 5 to 50 mg / l are known per se flotation auxiliaries and / or anion-active polyelectrolytes added.

According to a further preferred embodiment of the method according to the invention, the conditioning is carried out by adding perlite as a conditioning agent to the sludge in an amount of 2 to 6 kg perlite per m * sludge. The sludge is preferably thermally conditioned ^{at 80 to 120 °} C. for 3 *> 20 minutes with or without a conditioning agent.

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Advantageously, as alkali humate (s) -containing materials are those which are in a known manner in Wastewater or produced in part thereof are used. But it can also be produced separately Materials containing alkali humates are used. Furthermore, pure alkali humates or solutions of such can also be used, but this is less so is economical.

The inventive "method brings about the Prior art has the following advantages.

A) To be cleaned only technically respectively industrially manufactured materials connected with little effort are required, also can the alkali humate used for clarification from such materials and naturally occurring materials have been manufactured at the place of application; so the operating expense is low.

B) The reaction takes place in a few moments, which means that there are no containers to mix in the chemicals, flocculation tanks, retention tanks and other containers required for the reaction will; so the rubbing-in effort is low.

G) As that from the humic acid and impurities existing macromolecule when the acid or metal salts are added to the wastewater itself is formed and the bond between the individual components is not due to adsorption, but rather based on true chemical valence bonds, the degree of separation is high because it

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not only the suspended solids, but also a significant part of the dissolved organic matter Removed impurities.

D) In the case of less polluted wastewater (for example municipal wastewater), it is possible to use the cleaned Direct water into open waters without biological treatment.

E) Because when cleaning not only the suspended matter and dissolved organic substances, but also a significant part of the phosphorus and nitrogen compounds that cause eutrophysation removed is no special post-treatment (tertiary treatment) of the purified water required and it also caused at his Discharge directly into stagnant water in these no eutrophysation.

P) The residual organic matter content of the purified water can be found in conventional biological Cleaning systems can be further reduced in a simple manner.

G) The method according to the invention is also suitable for the tertiary treatment of biologically treated wastewater very well suited.

H) The sludge obtained is extremely suitable as a fertilizer due to its humic acid content.

The invention is illustrated by the following examples explained in more detail by means of the drawing.

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example 1

A chemical container 1 was filled with Eocene period lignite with a moisture content of about 20% by weight and an ash content of 20% by weight. 20% by weight of solid, ground potassium hydroxide (maximum particle size 20 mm) and 250% by weight of tap water, based on the lignite, were added ⁰ C. The mixture was left to stand for 12 hours and then diluted 3-fold with tap water. The potassium humate solution obtained had a residual carbon content of 35 g / l ·

The waste water was drawn from a container with a pump 3 2 through a pipe 5 into a flotation device 4 · pumped. The solution containing the potassium humate (and the non-dissolved charcoal components) was mixed with a pump 6 is pumped into the pipeline 5. From a Be The sulfuric acid required to adjust the pH value from 3 »0 to 3 $ 2 was supplied to container 7 by means of a pump 8 also pumped into the pipeline 5. Immediately before entering the flotation device 4-were into the pipeline 5 from a container 9 15 to 30% by weight of water in this under pressure of 4 atmospheres saturated with air is introduced.

The sludge formed and the purified water were discharged from the flotation device 4 separately.

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As the experiments showed, the reaction was instantaneous. After mixing in the potassium humabes respectively the addition of the acid and / or salts of divalent and / or trivalent metals (with regard to the latter see the following example 2) the formation of the macromolecules took place at the usual flow rate (0.5 to 2 m / second) at one to 20 to 50 times the Path length corresponding to the pipe diameter. Chemical mixing devices and flocculators were therefore not required.

The results compiled in Table 1 below were obtained with various waste waters.

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BATHROOM (QB

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State

of sewage

properties

respectively

Amount of type of waste water

Schlacnthof wastewater

Pork belly

ο ω OO Oi

uncleaned

chemical oxygen demand in mg / 1 500 to 3

12 000 to 16

after cleaning

purified water

mud

Rei-J Potassium carried in g / l nigung with \ sulfuric acid in g / l to 0.3 to 0.6

0.7 1.0

1 to 1.2 to

chemical oxygen demand in mg / 1 biological oxygen demand in mg / 1 Fat content in mg / 1 to to to

250

100

10

Amount in

Dry content in wt .- #

up to

4 6

14 5

until

until

1.5

1 200 to 1

18 6

-V

The conditioning of the accumulated sludge could wi "> must be carried out as follows:

Procedure a)

The resulting sludge was thermally conditioned, i.e. heated to the boiling point by introducing steam. After 5 minutes, ⁰ C was cooled to 4-O. The sludge was then filtered on a vacuum disk filter. the

Filter performance exceeded 30 kg / m. Hour. The filter cake had a dry matter content of 22 to 28% by weight.

The filter cake could be used as a fertilizer in horticulture and worked just as well as potassium humate.

Procedure b)

5 to 6 g / l perlite were added to the resulting sludge as a conditioning agent. Then the mud on a vacuum disc filter with a filter capacity of 50 to 60 kg / m. Hour filtered. The filter cake had a dry substance content of more than 30% by weight.

When replacing the potassium humate solution with residual carbon content Similar results were obtained using a sodium humate solution prepared analogously with residual carbon content achieved.

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Example 2

The procedure was as described in Example 1,

But with the difference that this time with a

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Aluminum sulfate solution or with an iron (II) - -sulfaüösung or mitpstner iron (III) chloride solution filled container 7 such was pumped with the pump S into the oil pipe 5. Water saturated with air from the container 9 was in an amount of 10 to 30 wt .-% added.

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So were used with various sewage the in the following Table 2 compiled results achieved.

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- 14 table

State
of
Sewage properties chemical £ Potassium humate in g / l
Aluminum sulfate in g / l
Iron (II) sulfate in g / l
Oxygen demand in mg / 1 400 Art
sewage bOO of Sewage
Slaughterhouse-
sewage ), 40 0
2 Phosphorus in mg / 1 7th until 15th 3 5OC 250 5 unge Nitrogen: Suspended solids in mg / 1 30th until 50 30 to cleans Oxygen demand in mg / 1 100 until 250 200 to 1,
1,
300 mg / 1 0
0
60 , until 0
0
70 - O, cleaned
tes
water m mg / 1 0 , 2 to
,1 to
until 0 , 6
A. 0.6 his
0.8 to
200 to Suspended solids in mg / 1 10 , 3 to 25th , 5 0.1 to took place
Cleaning *
with
chemical ί until - Phosphorus in

OO CD CZ)

- Λψ

The conditioning of the accumulated sludge could be carried out according to the procedures described in Example 1 with the same result.

When replacing the potassium humate solution with residual carbon content Similar results were obtained using a sodium humate solution prepared in the same way with residual carbon content.

Example 3

It became biologically treated household sewage in the device described in example 1 with 0.2 kg / nr potassium humate and / or sodium humate and 0.2 kg / m * Aluminum sulfate added. The sludge was separated by settling. The tables listed in Table 3 below were used Get results.

Table 3

properties raw
sewage purified
sewage chemical oxygen
requirement in mg / 1 70 24 Total nitrogen in mg / 1 27 5 Total phosphorus in mg / 1 6th 0.4 Suspended solids in mg / 1 70 25th

Claims

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Claims (8)

Claims 1.) Process for the chemical purification of wastewater containing dissolved organic impurities by adding acids or metal salts to these and separating the resulting precipitate, optionally with subsequent conditioning and filtering the same, and discharging the purified water, characterized in that the wastewater is first 1 or more 1 or more alkali humate (s) containing material (s) are added and then "... y as acid (s) or metal salt (s) 1 or V more mineral acid (s) and / or salt (e ) from * 2 and / or 3 ~ cast metals. 2.) Method according to claim 1, characterized in that that as alkali humate (s) potassium humate and / or Sodium humate used. 3 «) Process according to claim Λ or 2, characterized in that the alkali humate or the alkali huuaate is used in amounts of 0.2 to 2.0 kg per m of wastewater. 4.) Method according to claim 1 to 3 »characterized in that that the mineral acid (s) used is sulfuric acid, hydrochloric acid and / or phosphoric acid. 5.) Method according to claim 1 to 4, characterized in that that one uses the mineral acid (s) in such an amount that the pH value is below 4 sets. ^ - 17 Θ30035 / 0674 'BAD ORIGINAL 6.) Procedure according to. Claim 1 "to 5» characterized in that that the salt (s) of divalent and / or trivalent metals aluminum sulfate, iron (II) - -sulphate and / or iron (III) chloride used » 7.) Process according to claim 1 to 6, characterized in that the salt or the salts of 2- and / or 3 - '»vertigen metals are used in amounts of 0.2 to 2.0 kg per m / wastewater. 8.) Method according to claim 1 to 7 »characterized in that that when separating the sludge by flotation at the same time as the formation of the Introduces flakes into the water and air and optionally 5 to 50 mg / 1 per se known flotation auxiliaries and / or adding anion-active polyelectrolytes. 9.) Method according to claim 1 to 8, characterized in that that the conditioning is done by adding perlite as a conditioning agent to the sludge in an amount of 2 to 6 kg perlite per Br sludge performs. 10 ») Process according to claim 1 to %, characterized in that the materials containing alkali humate (s) are those which have been produced in a manner known per se in the waste water or in part thereof. 080035/0674 ORlRlWAL