DE3617848A1

DE3617848A1 - Process for removing heavy metals from sewage sludges or any type of sludges

Info

Publication number: DE3617848A1
Application number: DE19863617848
Authority: DE
Inventors: Heinz Dipl Ing Hoelter; Heinrich Dipl Ing Igelbuescher; Heinrich Ing Grad Gresch; Heribert Dipl Ing Dewert
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-05-27
Filing date: 1986-05-27
Publication date: 1987-12-03

Abstract

It is known to free sludges, in particular sewage sludges, from heavy metals so that they can be used as fertilisers. In order to achieve this simply with a high separation efficiency, according to the invention it is proposed that the sludges are dewatered and are then scoured, washed and dispersed in a solution of NTA or EDTA compounds and the sludge thus treated is transferred to fertiliser production. The water retained is passed through an electrolysis cell so that the metals present are separated off as completely as possible, which action is further intensified via vibration and/or ultrasonic vibration devices, so that the heavy metals are precipitated in the sump.

Description

Es ist bekannt, daß Schlämme, vorzugsweise Klärschlämme, von Metallen befreit werden sollen, damit diese als Dünger Anwendung finden.It is known that sludge, preferably sewage sludge, to be freed from metals so that they can be used as fertilizer Find application.

Erfindungsgemäß wird daher vorgeschlagen, eine Elektrolyse technik zu verwenden, die durch eine erfindungsgemäße Wasch flüssigkeit prozessual begünstigt wird.An electrolysis is therefore proposed according to the invention to use technology by a wash according to the invention process is favored.

Aus diesem Grunde wird folgender Verfahrensschritt vorge schlagen:For this reason, the following process step is featured beat:

1) Sewage sludge is drained over drainage devices via centrifuges and / or vacuum filter presses and the same drained as much as possible.
2) The sewage sludge is in an ethyl diamine tetra vinegar acid solution or rinsed in an NTA solution, washed, dissolved, and then again the sewage sludge, which now after the 2nd rinsing and washing of heavy metals the absorbent washing medium is cleaned, the fertilizer production passed, and the retained water is passed through an electrolytic cell.

Schwermetalle sind bekanntlich Kationen. Diese werden über ein Diaphragma, das zwischen Anode und Katode aufgehangen ist, weitgehendst abgeschieden und über Schwing- und/oder Ultraschallschwingeinrichtungen getrennt und im Schwer metallsumpf ausgefällt.Heavy metals are known to be cations. These are about a diaphragm suspended between the anode and cathode is largely separated and over vibration and / or Ultrasonic vibrators separated and heavy metal sump failed.

Selbstverständlich kann auch - bevor die letzte Entwäs serung stattfindet - der Schlamm gewässert werden und als wässrige Substanz durch die Elektrolyse hindurchgepumpt werden. Hierdurch wird man, wie die Untersuchungen gezeigt haben, die größtmögliche Abscheidung der Schwermetalle aus dem später zu verwendenden Düngemittel aus Klärschlamm erzielen.Of course you can - before the last draining saturation takes place - the sludge is watered and as aqueous substance pumped through the electrolysis will. This will make you like the exams shown have the greatest possible separation of heavy metals the sewage sludge fertilizer to be used later achieve.

Es ist bekannt, Schwermetalle aus Waschflüssigkeiten durch Elektrolysezellen abzuscheiden, jedoch Schwermetalle aus Klärschlämmen abzuscheiden, gehört nicht zum Stand der Tech nik.It is known to pass heavy metals from washing liquids To separate electrolytic cells, however, from heavy metals Separating sewage sludge is not part of the state of the art nik.

Dieses wird durch die obig beschriebenen erfindungs gemäßen Maßnahmen forciert, insbesondere durch die NTA- Flüssigkeit, die biologisch abbaubar ist und durch Diaphrag ma-Katoden- und Anodenzuordnung über Schwingtechnik er gänzt, und gleichzeitig durch die beschriebene Anordnung in einem Entwässerungsbecken auch gleichzeitig die Sedimentation forciert wird, d.h. schnellere Entwässerung bei gleichzei tiger Abscheidung von Schwermetallen.This is fiction, described by the above appropriate measures, especially by the NTA Liquid that is biodegradable and through diaphragm Ma-cathode and anode assignment via vibration technology complements, and at the same time through the arrangement described in sedimentation in a drainage basin is forced, i.e. faster drainage at the same time deposition of heavy metals.

Claims

1. Process for the removal of heavy metals from sewage sludge and other types of sludge characterized in that the sewage sludge is dewatered or dissolved in an aqueous solution according to the invention, the solution consisting of NTA or EDTA compounds, preferably NTA, because this liquid is biodegradable, a diaphragm being used according to the invention between the cathode and anode in the electrolysis cell, and that the liquid is excited by vibrations and / or by ultrasonic vibrations in order to achieve a better ion flow and to force sedimentation of the heavy metals between the cathode, anode and diaphragm .

2. The method according to claim 1, characterized in that the sludge to be disposed of is fed into the precipitation tank, being in these precipitation tanks for drainage and Heavy metal precipitation electrolysis technologies, which in Claim 1 are described, take effect with the Vibration technology is not just a separation of the heavy allow metals from the sludge and water, son also a better sedimentation process keep the sludge from the washing liquid down achieve settling basin.