CH459081A - Treatment process for sludge from sewage - Google Patents

Description

  

  Method for treating sludge from sewage water The subject of the present invention is a method for treating sludge originating from sewage water.



  Generally, sludge from sewage water has a moisture content of about 95% by weight, so by itself it is not suitable for the formation of compost, and sludge alone cannot either. be dehydrated satisfactorily in known presses, while the usual filtration means are expensive.

   We have found that if the slurry is mixed with fibrous and / or sandy material, it is possible to remove some of the liquid content by pressing.



  In accordance with the present invention, the sludge from the sewage water, the water content of which it is desired to reduce, is mixed with a fibrous and / or sandy material, then it is pressed in order to reduce its liquid content.

   Preferably, the fibrous material and / or its blonneuse consists of municipal waste compounds generally having a moisture content of between 35% and 60% by weight. The pressed cake can be mixed with municipal rubbish or with a new amount of sludge and then pressed again.

         It can then be transferred to a postage plant, it can be disposed of by incineration, used for landfill, landfill or used as fertilizer.



  The mixture can be pressed in a screw press, a ram press or other mechanical press of conventional construction, in order to form a pressed cake with a concentration of about 70% by weight;

          it can then be used for composting or for incineration, or else pressed to as low a water content as possible and it can then be spread as a fertilizer.



  In one example, a mixture of equal parts by weight of primary fouling sludge having a water content of 92% by weight and Dano compost having a water content of <RTI is pressed.

   ID = "0001.0081"> 58% by weight (the mixture therefore has a water content of 75% by weight)

          in a hydraulic press having a perforated press cage at a relative pressure of 14 kg / cm2 in order to lower the water content to 57% by weight. The pressed cake can then be mixed with a new quantity of primary mud in order to

      increase its water content to 70% by weight and then compost the mixture in a composting plant. In facilities known for composting municipal trash, it is usually necessary to add water to the trash.

   On the other hand, the humidity to be added to the composting plant is reduced or eliminated when using the pressed product to which primary sludge has been added.

 

Claims (1)

CLAIM I Process for the treatment of sludge from sewage water, the water content of which is desired to be reduced, characterized in that the sludge from sewage water is mixed with a fibrous and / or sandy material; then in that the mixture is pressed in order to reduce its moisture content. SUB-CLAIMS 1. Method according to claim I, characterized in that the fibrous and / or sandy material is constituted by municipal rubbish transformed into com post. 2. Method according to claim I, characterized in that the fibrous and / or sandy material is constituted by ground municipal rubbish. 3. Process according to Claim I or one of sub-claims 1 or 2, characterized in that the mixture is pressed until it has a moisture content of between 70 and 80% by weight. 4. Method according to claim I, characterized in that the pressed material is mixed with a new quantity of sludge and then pressed again. CLAIM II Use of the sludge with reduced water content obtained by the process according to claim I for the manufacture of compost.