SU812771A1 - Method of treatment of waste water precipitates - Google Patents

Description

 . ,one - ; The invention relates to the treatment of sewage sludge and can be used in the processing technology of fecal sludge and some sewage sludge.

Closest to the proposed technical essence and the achieved effect is a method of treating sludge, including drying the sludge in the presence of ash 1.

The disadvantage of this method. It is impossible to obtain a granular product suitable for use as an agricultural fertilizer.

The purpose of the invention is to obtain a granular product suitable for use as an agricultural fertilizer.

To achieve this goal, shale ash of pulverized consistency is used in the amount of ash in the amount of 50-70% of the weight of the sludge being processed.

An example. Fermented fecal sludge iodine from methane, tanks with initial humidity of 96.5%, intended for drying on sludge beds, was sent to a special mixer, in which the precipitate in

various weight ratios added pulverized slate ash. In various series of experiments, the weight amount of the added ash was from 10 to 100% of the weight of the treated sludge. After thoroughly mixing with a mesh for 3-5 minutes at a speed of 8 rpm, the resulting mass was released into a special container.

0 At the same time the humidity of the fermented siege. Each of the digesters varied from 96.2 to 96.8% and averaged 96., 5%, and ash was dust collected from flue gases in multicyclones of the Baltic SDPP operating on combustible shale.

The composition of the ash was characterized by the following indicators,%; the amount of calcium and magnesium in terms of

0 on calcium carbonate CaCo 61.5; potassium oxide content 1.79; the phosphorus content in terms of 1.24; sodium oxide content 0.12; content of titanium dioxide 0; 43; dioxide

5 aluminum 5.4; the content of iron oxide 5, the content of silicon oxide 21,53; residual moisture content of 1.44.

Depending on the ratio of the mixed components of ash and sediment)

0

and the exposure time, the humidity of the finished product after 48 hours ranged from 22 to 55%.

However, in all series of experiments with the addition of not less than 20% ash from the weight of the precipitate after 48 hours, the product has the consistency of the product, and the moisture content in the product does not exceed 50%,

The dewatering process takes place both due to the direct removal of moisture (due to the high hygroscopicity of the ash) f as due to the intensification of drying the mixture obtained {due to a change in the structure: the resulting mass). At the same time, there is a significant reduction in time, obtaining a bulk product suitable for mechanized loading and transportation.

As the amount of added ash increases, the moisture content of the resulting product decreases, moreover, starting from 60%: {ash From the weight of the precipitate) time does not significantly affect the drying of the mixture. Together with heme, with an increase in the amount of my ash added to more than 70% of the weight of the precipitate, lumps appear in the mixture. This is due to the insufficient amount of moisture in the sediment required

for uniform wetting of added ash. The formation of lumps impairs the technology of mechanized use of the resulting mixture as a fertilizer in agriculture. Used in agriculture as a fertilizer, the resulting dried sewage sludge contains valuable organic compounds (nitrogen and phosphorus), as well as calcium, potassium, magnesium, mineral phosphorus, and a number of trace elements.

Claims (1)

Invention Formula The method of treating sewage sludge, which includes drying the sludge in the presence of ash (characterized in that, in order to obtain a granular product suitable for use as a fertilizer in agriculture / as shale, 50-70% of slate ash is used as ash weight of the treated sludge. ..-. Sources of information taken into account in the examination 1, Patent GDR about 55622f CL, -85 C 6/09, 1967 (prototype).