CS205671B1 - Method of cleaning the waste waters from the surface dressing of metals containing the ammonium compounds - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for the purification of waste water from metal surface treatment plants which contain ammonium compounds having buffering or complexing properties.

Because of these buffers and their complexing properties, waste waters containing ammonium compounds cannot be treated together with other waste waters from metal surface treatment. Nowadays, cyanide-free baths are increasingly being used for plating instead of cyanide-containing baths. These cyanide-free baths usually contain ammonium complexes with non-ferrous metals, which then pass to wastewater during rinsing.

_P solves odpadníoh water purification process according to the invention which consists in that an ammonium compound having decomposed by biological means by seeding with the addition of activated sludge substance podporujío'í aerobic decomposition.

The cleaning method is as follows: «

If there is a greater amount of soluble metal salts (Cd, Zn, Cu, Ni, Ve) in the wastewater than would be acceptable for the biodegradation of the ammonium compounds present, these salts are first removed by acidification and then precipitated by alkali (lime) or with caustic soda or the like). To the ammonium complexes that remain in the water, add another biological process (trisodium phosphate or superphosphate or hexamethylene phosphate)

205 671

209 071 and any biowaste of sewage origin from the biological process. At the start of the biological well-being, the mixture is inoculated with active sludge.

A biological aerobic well-being occurs in which the ammonia compounds decompose up to 95 to 99% by weight and its maximum 5% by weight in the waste water ceases to have a buffering effect.

The remainder of the non-precipitated metal salt passes into the sediment in insoluble form.

An advantage of the process according to the invention lies in the simple, economical theological treatment of waste water from modern plating-free cyanide baths.

Example 1

The plant has its own biological treatment tent for sewage water. An additional aerobic process is added to the anaerobic purification process. After treating the waste water from the ammonium compound content with 5% by weight trisodium phosphate (approximately 5 kg / 50 m ³ ), it is then discharged into a sewage treatment plant. Water purified in this way no longer has a buffering effect.

Example 2

The plant does not have its own biological sewage treatment plant for wastewater and discharges the waste water into the public sewer from where it is led to the municipal sewage plant. Such untreated water could, in large quantities, disturb the biological balance of the purification of all wastewater in this tinfoil.

To avoid this, it is adjusted in advance:

(a) removing a major part of the metal salts from it by acidification and addition of lime to leach.

Some of the metals got into the sediment,

b) add biological promoting agent - in this case superphosphate 3 kg per 20 m ³ ,

o) aerating from a

(d) allow sedlmentaoe to proceed. ,

Olsten can then be discharged into the public sewer for cleaning purposes.

Example 3

The plant does not have its own biological wastewater treatment stanol for sewage and there is no public wastewater treatment station stanioe.

Waste water containing ammonium compounds is treated by adding hexamethylene phosphate

150 g / m ³ and sewage (20 to 50 l / m ³ - depending on its activity) and after initial seeding with active sludge it can aerate for 2 to 3 hours using an aerator or compressed air. After aerobic decomposition and after sedimentaol, pure water is discharged into water3

205 671 TOC ·.

The sludge is pumped onto the dewatering device and can also be used as fertilizer.

Claims (1)

A method of treating waste waters from the treatment of metals containing ammonium compounds, characterized in that the waste waters are treated at the start of the treatment by the addition of a biological promoting agent, for example trisodium phosphate in an amount of 10 to 200 g / m ³ or 10 to 200 g / m ³ or hexamethylene phosphate in an amount of 5 to 150 g / m ³ , and the treated water is mixed with municipal waste water or other biological sewage that are capable of decomposing themselves after the initial seeding with active sludge aerobic march.