WO2008039092A1

WO2008039092A1 - Composition for detoxifying sludge of waste treatment plants, method for the production thereof and method for detoxifying sludge of waste treatment plants

Info

Publication number: WO2008039092A1
Application number: PCT/RU2006/000499
Authority: WO
Inventors: Marina Eduardovna Korotkova; Igor Anatolievich Zhirnokleev; Boris Konstantinovich Nefedov; Yevgeniy Grigoryevich Gorlov; Alexandr Yevgenyevich Antonov
Original assignee: Igor Anatolievich Zhirnokleev
Priority date: 2006-09-28
Filing date: 2006-09-28
Publication date: 2008-04-03

Abstract

The invention can be used for detoxifying sludge of waste treatment plants. The inventive method for detoxifying sludge of waste treatment plants consists in determining the content of heavy metals therein and in calculating the required quantity of composition which contains 8.2-9.2 mass% hydrates of sodium or potassium salts of an aminoacid mixture, 3.6-4.4 mass% hydrates of sodium or potassium salts of low-molecular peptides, 0.05-0.06 mass% alkali, the rest being water. The composition is obtainable by exposing waste containing animal proteins to water-thermal treatment in the presence of alkali, wherein the waste, water and alkali are taken at a ratio of 1: (1.8-2.0): (0.19-0.37) and the treatment is carried out at a temperature ranging from 120-180°C for 25-90 min.

Description

Composition for detoxification of sludge from sewage treatment plants, method for its preparation and method of detoxification of sludge from sewage treatment plants

The invention relates to precipitation detoxification treatment plants containing heavy metals in quantities exceeding permissible limits, as well as detoxification technologically-affected land and can ^'be used in the system of housing and communal services of cities.

Wastewater sludge from municipal and industrial wastewater treatment plants, even after biothermal and biological treatment and stored at silt sites of treatment facilities, are waste of toxicity class II and III, as they contain heavy metal cations in significant quantities.

BACKGROUND

A known composition for detoxification of sewage treatment plants containing hydrates of sodium or potassium salts of a mixture of amino acids, alkali and water (Friedman AL and other organomineral compositions based on sewage sludge from sewage treatment plants. M. Non-Profit Partnership "Chemical and Technological Scientific Center ”, M., 2000, pp. 75-87) [1]. However, the effectiveness of this known composition is not high enough.

A known method of obtaining a composition for detoxification of treatment facilities by conducting thermal input treatment in the presence of alkali waste containing animal proteins [1].

However, the parameters of the process of conducting the heat-treatment in the presence of alkali of waste containing animal proteins are not described in this known method. Moreover, the method leads to the production of a composition which does not include components in the form of hydrates of sodium or potassium salts of low molecular weight peptides that increase the efficiency of the detoxification process of sludge from treatment facilities. A known method of detoxification of sludge from sewage treatment plants by extracting heavy metals from sludge cation exchange or complexing agents

(Agranonik P. Ya. Problems of treatment and disposal of sewage sludge. Water supply and sanitary equipment. 1995. N_> 1. Pp. 2–3.) [2].

However, this known method provides for the use of expensive reagents for detoxification, high complexity and high energy consumption.

A known method of detoxification of sludge from treatment plants by their treatment with a detoxifier [1].

As a detoxicant in this known method, a composition is used containing hydrates of sodium or potassium salts of a mixture of amino acids, alkali and water.

However, the effectiveness of this known method is not high enough. SUMMARY OF THE INVENTION

The technical result achieved by the present invention is to increase the efficiency of detoxification of sludge from treatment facilities. The specified technical result is achieved by the fact that the composition for detoxification of sewage treatment plants containing hydrates of sodium or potassium salts of a mixture of amino acids and hydrates of sodium or potassium salts of low molecular weight peptides obtained by water-heat treatment in the presence of alkali waste containing animal proteins, water and alkali , in the following ratio of components, May%: hydrates of sodium or potassium salts of a mixture of amino acids 8.2-9.2 hydrates of sodium or potassium salts of low molecular weight peptides Dov 3.6-4.2 alkali 0.05-0.06 water the rest.

This technical result is also achieved by the fact that in the method for producing a composition for detoxifying treatment facilities by water-thermal treatment in the presence of alkali of waste containing animal proteins, a distinctive feature is that the mixture is treated with water and alkali, taken in the ratio equal to 1: (1.8-2.0): (0.19-0.37), at a temperature of 120 - 180 ⁰ C for 25 - 90 minutes to obtain the target product in the form of a composition according to claim 1.

In addition, the specified technical result is achieved in the method of detoxification of sludge from treatment plants by their treatment with a detoxicant due to the fact that the composition according to p.

γJbPsch, ^2m Cu, ^3m Cr, Schm, 2 ™ _C o, ^2m Zп, ² ™ Pb ^ ^"

I ₄ 549 63.5 51.9 56.7 56.9 65.4 207.2 1124,

where V is the flow rate of IM solution of a detoxicant, l / m ³ ; t - the content of heavy metal in the cleaned sludge in terms of the absolutely dry substance of the sludge, g / kg, and a detoxicant is consumed with an excess of 20-30% relative to the calculated amount.

MODES FOR CARRYING OUT THE INVENTION

The following are examples illustrating the invention.

Example 1. In a reactor with a capacity of 250 l, 108 l of water is loaded, 11.5 kg of sodium hydroxide are added in portions of 3 kg and then 60 kg of waste containing animal proteins (hair tows of cloth-felting production, waste hair from ventilation collection during the initial processing of wool, waste of fur dressing, production of valency products), tamping them if necessary. The ratio of waste: water: alkali is 1: 1.8:

0.19. The steam supply valve is opened and the reaction mass is heated until circulation begins through the pipeline supplying steam to the expansion vessel — the refrigerator, and through the pipeline returning condensate to the reactor. The process is carried out at a temperature of 120 ⁰ C. With a complete supply of steam, the mass is kept in a state of circulation for 75 minutes. Block feed steam into the reactor and incubated for 15 minutes after the termination of circulation. Shake the reactor lid, add water to a total reaction volume of 200 l and mix the mixture for 15 minutes. The reaction mixture is drained through a filter into a decanter. Get 2M aqueous solution of detoxicant - composition according to claim 1. with an average molecular weight of 130, with a content (wt.%): sodium salt hydrates of a mixture of amino acids (alanine, valine, glycine, leucine, isoleucine, proline, phenylalanane, oxoproline, serine, tyrosine, threonine, arginine, histidine, lysine, oxylysine, cysteine, cystine, methionone, aspartic acid and glutamic acid) - 9.2; hydrates of sodium salts of low molecular weight peptides - 3.6, sodium hydroxide - 0.05 (free alkali content of 0.08 mol / l); the rest is water. Example 2. 120 l of water is loaded into a 250-liter reactor, 13.8 kg of sodium hydroxide are added in 2 kg portions, and then 60 kg of waste containing animal proteins (tanning leather, substandard fur and leather raw materials), tamping them if necessary . The ratio of waste: water: alkali is 1: 2.0: 0.37. The steam supply valve is opened, the reaction mixture is heated until circulation begins through the pipeline supplying steam to the expansion vessel — the refrigerator, and through the pipeline returning condensate to the reactor. The process is carried out at a temperature of 160 ⁰ C. With a complete supply of steam, the mass is kept in a state of circulation for 25 minutes. Block the steam supply to the reactor and incubated for 15 minutes after the cessation of circulation. Shake the reactor lid, add water to a total reaction volume of 200 l and mix the mass for 15 minutes The reaction mixture is drained through a filter into a decanter. Get 2M aqueous solution of detoxicant - composition according to claim 1 with an average molecular weight of 136 with a content (wt.%): Sodium hydrates of a mixture of amino acids (alanine, valine, glycine, leucine, isoleucine, proline, phenylalanane, oxoproline, serine, tyrosine, threonine, arginine, histidine, lysine, oxylysine, cysteine, cystine, methionone, aspartic acid and glutamic acid) - 8.2; hydrates of sodium salts of low molecular weight peptides - 4.2, sodium hydroxide - 0.06 (free alkali content of 0.065 mol / l); the rest is water.

Example 3. 114 liters of water are loaded into a 250-liter reactor, 12 kg of potassium hydroxide are added in portions of 2 kg and then 60 kg of waste containing animal proteins (tanning leather, substandard fur and leather raw materials), ramming them if necessary. The steam supply valve is opened, the reaction mass is heated until circulation begins through the pipeline supplying steam to the expansion vessel — the refrigerator, and through the pipeline returning condensate to the reactor. The process is carried out at a temperature of 180 ⁰ C. The ratio of waste: water: alkali is 1: 1.9: 0.25. When the steam is fully supplied, the mass is kept in a circulated state for 15 minutes. Block the steam supply to the reactor and incubated for 10 minutes after the cessation of circulation. The reactor lid is shaken, 85 l of water are added (up to a total reaction volume of 200 l), and the mass is stirred for i5 min. The reaction mixture is drained through a filter into a decanter. Get 2M aqueous solution of detoxicant - composition according to claim 1 with an average molecular weight 135 with a content (wt.%): sodium salt hydrates of a mixture of amino acids (alanine, valine, glycine, leucine, isoleucine, proline, phenylalanan, oxoproline, serine, tyrosine, threonine, arginine, histidine, lysine, oxylysine, cysteine, cystine , methionone, aspartic acid and glutamic acid) - 8.4; hydrates of sodium salts of low molecular weight peptides - 3.8, sodium hydroxide - 0.05 (free alkali content of 0.06 mol / l); the rest is water.

Example 4. The sludge of urban wastewater treatment plants, placed on a sludge map with a moisture content of 61% in the amount of PO t (separated part of the sludge map), was treated with irrigation with the composition according to claim 1, obtained according to example 1. The composition was pre-diluted to a concentration of 0.1 mol / l According to the data of chemical analysis, the precipitate contained (mg / kg dry matter): Cu - 795, Zn - 1530, Ni - 275, Cr - 553, Pb - 120, Cd - 98, Co - 20. The required amount of composition according to item l was calculated based on a mathematical expression:

where V is the consumption of detoxicant IM concentration, l / m-, t is the content of heavy metal in need of detoxification in the sediment, calculated on absolutely dry substance g / kg. The amount of detoxicant was calculated as PO 1 of a 0.1 molar solution. Irrigation of the surface of the sediment was carried out using a distribution device that moves along the boundaries of the sludge site. 132 L of a 0.1 molar reagent solution (1, 2-fold excess) was consumed during processing for 8 hour. The treated part of the sludge map was kept for 25 days, periodically measuring the pH. On the 15th day, the pH reached 7.6 and then did not decrease. Treated sediment has a smell of soil. According to biotesting data (according to the Order of the Ministry of Natural Resources of the Russian Federation of June 15, 2001 JVfe 511), the resulting organomineral composition is non-toxic to living organisms and is a substance of hazard class 4. In accordance with GOST P 17.4.3.07-2001, it can be used to restore the productivity of disturbed lands for the purpose of forestry and recreational direction of their restoration, as well as as raw materials for the preparation of organic fertilizers by composting and vermicomposting.

Thus, the composition according to the invention, obtained by the method according to the invention, provides a high detoxification efficiency ^'of sludge from treatment facilities.

Claims

Claim

1. Composition for detoxification of sewage treatment plants containing hydrates of sodium or potassium salts of a mixture of amino acids and hydrates of sodium or potassium salts of low molecular weight peptides obtained by conducting water-heat treatment in the presence of alkali waste containing animal proteins, water and alkali, in the following ratio of components , May%: hydrates of sodium or potassium salts of a mixture of amino acids 8.2-9.2 hydrates of sodium or potassium salts of low molecular weight peptides 3.6-4.2 alkali 0.05-0.06 other water.

2. A method of obtaining a composition for detoxification of sludge from sewage treatment plants by carrying out water-heat treatment in the presence of alkali of waste containing animal proteins, characterized in that the mixture is treated with said waste with water and alkali, taken in a ratio of 1: (1.8- 2.0): (0.19-0.37), at a temperature of 120 - 180 ⁰ C for 25 - 90 minutes to obtain the target product in the form of a composition according to claim 1.

3. The method of detoxification of sludge from treatment facilities by treating them with a detoxicant, characterized in that the composition according to claim 1 is used as a detoxicant, and the content of ions of each heavy metal in the sludge to be purified is preliminarily determined, the detoxicant consumption is calculated based on the mathematical expression:

γ \ ^2m Mп, ^2m Cu, ^3m Cr, ^2m Ni, ^2m Co, ^2m Zп, ² Щb, ^2m Cd \

549 63.5 51.9 56.7 56.9 65.4 207.2 1124 J where F is the flow rate of the IM solution of the detoxicant, l / m ³ , t is the heavy metal content in the cleaned sediment in terms of absolutely dry matter, g / kg, and the detoxicant is consumed in excess of 20-30% relative to the calculated amount.