SU829596A1 - Method of treatment of lignine-containing waste precipitates - Google Patents

Description

The invention relates to methods for treating sewage sludge and can be used for treating sludge from sewage sulphate pulp production.

A known method of processing precipitation, including saturating it with air, heating and flotation compaction].

The closest to the proposed technical essence and the achieved result is a method of treating lignin-containing sewage sludge, including the introduction of polyacrylamide, compression by pressure flotation, introduction of sawdust into the compacted precipitate, and dehydration by filter pressing followed by thermal drying [2].

The disadvantage of these methods is the high residual moisture content of the treated sludge. So, the residual moisture content of the precipitate after complete processing is 83-8 7%.

The purpose of the invention is the reduction of residual moisture.

The goal is achieved in that according to the method, instead of introducing wood sawdust after compaction by pressure flotation, a powdery precipitate obtained at the stage of thermal drying is introduced as an organic additive. Powdered dry sludge is introduced in the ratio to the treated sludge 1: 1 - 1: 2.

To perform the method, polyacrylamide is introduced into the lignin sludge and subjected to pressure flotation compaction. After that, pre-dehydrated and dried to a moisture content of about 20% powdery lignin sludge obtained in the last processing stage is introduced into the condensed precipitate. Powdered sludge lignin is introduced into the compacted sediment at a ratio of 1: 1-1: 2. The mixed crude and dry precipitate is mixed and subjected to filter compression and then heat drying.

Example 15 mg of polyacrylamide in the form of a 1% solution per 1 g of absolutely dry sludge is introduced into the sludge lignin obtained after wastewater treatment of a sulphate-cellulose mill and compacted in a pressure flotator. Powdered slurry-lignin is preliminarily dehydrated and dried to 20% moisture after the stage of thermal drying in a ratio of 1: 1.5. The mixture is stirred with a mechanical stirrer at 960 rpm and subjected to filter pressing in a laboratory filter press. The precipitate, dehydrated by filter pressing, is subjected to thermal drying in a laboratory oven at 110 ° C to a moisture content of 20%. The moisture content of the filter cake is 75%.

The advantages of the proposed method include reducing the moisture content of the processed sludge by filtering from 83-87 to 75%, which leads to a reduction in fuel costs for subsequent thermal drying.

Furthermore, according to a method for increasing productivity filtrpres- ²⁵

A2S596 capping equipment filtering properties by increasing sludge.

Claims (2)

The invention relates to methods for treating sediment of the spill waters and can be used for treating the sediments of the stony waters of the sulphate pulp production. Izvesgen is a method of treating sediments, including saturation with air, heating and flotation compaction: The closest to the proposed technical essence and the achieved result is a method of treating lignin-containing sediments of sewage water, including introduction of polyacrylamide, compaction by means of flotation flooding, introduction of opllo and dewatering filterpress followed by thermal drying G2. The disadvantage of these methods is the high residual moisture of the treated sludge. Thus, the residual moisture of the precipitate after complete treatment is 83-87%. The purpose of the invention is to reduce the residual moisture. The goal is achieved by haem, that according to the method, instead of introducing sawdust after compaction by pressure flotation, the powder precipitate obtained at the heat-drying stage is introduced as an organic additive. Powdered dry sediment is introduced into the processed precipitate 1: 1 - 1: 2. In order to carry out the process, popiacrylamide is introduced into the slurry lignin and compacted by pressure flotation. Thereafter, poro-lumpy sludge-lignin, previously dewatered and dried to a moisture content of about 20%, is introduced into the thickened sediment, which is obtained at the last stage of processing. Powdered sludge is introduced into the compacted sediment at a ratio of 1: 1-1: 2. The mixed c and the dry precipitate is mixed and subjected to filtration, and then germinated. Prim p. In the lignin sludge, 1T; after the sewage treatment of the su / gfatsechtpahn of the combine, it was introduced 15 mg of popacrylamide in the form of a solution to 1 g of an absolutely dry sludge and subjected to a thickener in a pressure flotation apparatus. The dried slurry was dried and dried and the dried in a pressure flotation cell. moisture powdery sludge-lignin after the stage of thermal drying in the ratio of 1: 1.5. The mixture is stirred with a mechanical stirrer at 960 rpm and subjected to filter pressing in a laboratory press filter press. The precipitate dehydrated by filter pressing is thermally dried in a laboratory with a dryer at lid C to a moisture content of 2О%. The moisture content of the precipitate after filtration is 75%. The advantages of the proposed method include reducing the moisture content of the treated sludge by filtering it from 83-87% to 75%, which leads to a reduction in the cost of fuel for the subsequent thermal drying. In addition, according to the method, the capacity for filtering equipment is increased by increasing the filtering properties of the sludge. Claim Method A method for treating lignin-containing sewage sludge, including the introduction of polyacrylamide, compaction by pressure flotation, the introduction of an organic additive, and the dehydration by filtration, followed by thermal drying, characterized in that, in order to reduce the residual moisture, a powdery precipitate is added as an organic additive stage thermal drying. Sources of information taken into account in the examination 1. USSR author's certificate in application N 2648286/26, cl. S O2 S Z / OO, 1978. 2. Chemical engineering, 1974, No. 66. with. 32-62 (prototype).