Copper solvent extraction reagent, Nickel Cobalt extractant, DEHPA & Rare earth leaching solvent

Metal leaching solvent

Preparation method and application of sludge heavy

by:Deyuan      2020-12-17

Summary

The invention discloses a sludge heavy metal extractant, which is composed of the following components: polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, dodecyl sulfonate Sodium is 1.0-2.0%, the rest is solvent distilled water, the total amount of the above components is 100%. The invention also discloses a preparation method of the sludge heavy metal extractant. The above-mentioned raw material components are dissolved to prepare three solutions and then they are mixed. The solution preparation process and the mixing process are both at a certain temperature and stirring speed get on. The invention also discloses a method for sludge treatment using the above-mentioned sludge heavy metal extractant. The sludge is pre-shrinked first, and then the sludge heavy metal extractant is added, after conditioning and reacting in a conditioning tank for a period of time. After time, deep dehydration is carried out to obtain sludge after heavy metal extraction. The invention solves the problems of long treatment cycle, high operating cost and poor heavy metal removal effect in the prior art when carrying out sludge heavy metal removal and dehydration treatment.

   Claims

1. Sludge heavy metal extractant, which is characterized in that it is composed of the following components, polyaluminum chloride, polyacrylamide abbreviation, ethylenediaminetetraacetic acid, sodium lauryl sulfonate, sodium hydroxide, and solvent distilled water; The content of each component is as follows: polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, sodium lauryl sulfonate 1.0-2.0%, and the rest Distilled water as a solvent, the total amount of the above components is 100%.

  2. The method for preparing the sludge heavy metal extractant according to claim 1, wherein the method is specifically carried out according to the following steps:

Step 1. Weigh the raw materials according to the following formula, polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, sodium lauryl sulfonate 1.0-2.0%, and the rest Distilled water as a solvent, the total amount of the above components is 100%;

Step 2. Dissolve the solid raw materials weighed in step 1 and 4 in distilled water to prepare three solutions: polyaluminum chloride solution, ethylenediaminetetraacetic acid solution, and a mixed solution of polyacrylamide and sodium dodecyl sulfonate ; The preparation process is stirred at a speed of 80-100 revolutions per minute, heating is carried out, and the temperature of the solution is controlled between 25 and 30 ℃ until there is no obvious precipitation in the solution;

   step 3, the 3 solutions prepared in step 2 are mixed, and the mixing process is stirred at a speed of 80 to 100 revolutions per minute, heated appropriately, and the temperature of the solution is controlled between 25 and 30 ℃;

  Step 4, adjust the pH of the solution prepared in Step 3 to 9-10 with NaOH solution to obtain the sludge heavy metal extractant.

3. The method for sludge treatment using the sludge heavy metal extractant according to claim 1, wherein the sludge heavy metal extractant is composed of the following components, polyaluminum chloride, polyacrylamide for short, Ethylenediaminetetraacetic acid, sodium dodecyl sulfonate, sodium hydroxide, and solvent distilled water. The content of each component is as follows: polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, sodium lauryl sulfonate 1.0-2.0%, the rest is solvent distilled water , The total amount of the above components is 100%;

   Follow the steps below:

   step 1, the sludge is pre-shrunk treatment, so that the moisture content of the sludge will be below 97%, to obtain concentrated sludge;

   step 2, add sludge heavy metal extractant to the concentrated sludge obtained in step 1, and add 0.7 to 0.9 tons of sludge heavy metal extractant per 100 tons of concentrated sludge;

  Step 3, conditioning, that is, the concentrated sludge in step 2 and the heavy metal extractant of the sludge are thoroughly mixed. The temperature of the sludge in the conditioning process can be between 10 and 35 ℃, and the sludge can be stirred uniformly;

'Step 4, the mixture after conditioning in step 3 stays in the conditioning tank for 30 to 40 minutes;

  Step 5, the mixture after step 4 is deeply dehydrated by a plate and frame filter press to reduce the water content to 55% to 60%, and the sludge after heavy metal extraction is obtained.

   manual

   Preparation method and application of sludge heavy metal extractant

  Technical field

The present invention belongs to the technical field of sludge treatment and resource utilization, and relates to a sludge heavy metal extractant. The present invention also relates to a preparation method of the above sludge heavy metal extractant and a method for applying the above sludge heavy metal extractant for sludge treatment. method.

Background technique

  Sludge is a by-product produced in the process of sewage treatment by urban sewage treatment plants. It is generally a solid sediment formed by a settling tank sludge and excess activated sludge. The water content of the sludge is around 99%. Usually, the sludge is concentrated in the gravity thickening tank before entering the subsequent processing unit for deep dehydration treatment. Generally, the water content will be reduced to about 80%.

The composition of sludge is complex. It is a collection of mycelium formed by a variety of microorganisms and adsorbed organic and inorganic substances. The amount of organic matter and plant nutrients such as nitrogen, phosphorus and potassium contained in it is no less than that of livestock and poultry manure. Other farmyard manure is a good organic fertilizer substrate. This is also the reason why sludge can be recycled and used for fermentation and composting to prepare various organic fertilizers or soil amendments.

   But in addition to nutrients, sludge from different sources often contains some harmful substances, such as a variety of heavy metals, organic pollutants, pathogenic microorganisms and parasite eggs. In particular, the heavy metals are difficult to remove and have the characteristics of multiple sources, concealment, and serious pollution consequences. Therefore, they have become one of the hot and difficult issues in international environmental research. This also severely restricted the land use of sludge in agriculture and forestry, making it impossible to develop one of the most important ways of sludge resource utilization.

   If a simple and efficient agent or method for removing heavy metals in sludge can be found, so that the content of heavy metals in discharged sludge can reach the standard, it will greatly promote the land use of sludge and realize the utilization of waste resources.

At present, the commonly used heavy metal removal methods include biological leaching, phytoremediation, etc. They have long treatment cycles, high operating costs, poor removal effects, large area, limited capacity for long-term treatment, and are not suitable for hundreds of thousands of tons per day. Treatment of sludge from large and medium-sized sewage plants.

  Invention content

   The object of the present invention is to provide a sludge heavy metal extractant, which solves the problems of long treatment period, high operating cost and poor heavy metal removal effect in the prior art for heavy metal removal and dehydration treatment of sludge.

'Another object of the present invention is to provide a method for preparing the above-mentioned sludge heavy metal extractant.

   Another object of the present invention is to provide a method for sludge treatment using the above-mentioned sludge heavy metal extractant.

The technical scheme adopted in the present invention is that the sludge heavy metal extractant is composed of the following components: polyaluminum chloride, polyacrylamide abbreviation, ethylenediaminetetraacetic acid, sodium lauryl sulfonate, sodium hydroxide and solvent Distilled water; The content of each component is as follows: polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, sodium dodecyl sulfonate 1.0-2.0% , The rest is solvent distilled water, the total amount of the above components is 100%.

   Another technical solution of the present invention is that the method for preparing the above-mentioned sludge heavy metal extractant is specifically carried out according to the following steps:

Step 1. Weigh the raw materials according to the following formula, polyaluminum chloride 8-15%, polyacrylamide 0.3-0.6%, ethylenediaminetetraacetic acid 1.8-2.4%, sodium lauryl sulfonate 1.0-2.0%, and the rest Distilled water as a solvent, the total amount of the above components is 100%;

Step 2. Dissolve the solid raw materials weighed in step 1 in 4 with distilled water to prepare three solutions: polyaluminum chloride solution, ethylenediaminetetraacetic acid solution, and mixed solution of polyacrylamide and sodium dodecyl sulfonate . The preparation process is all stirred at a speed of 80-100 revolutions per minute, heating is carried out, and the temperature of the solution is controlled between 25 and 30 ℃ until there is no obvious precipitation in the solution;

   step 3, the 3 solutions prepared in step 2 are mixed, and the mixing process is stirred at a speed of 80 to 100 revolutions per minute, heated appropriately, and the temperature of the solution is controlled between 25 and 30 ℃;

  Step 4, adjust the pH of the solution prepared in Step 3 to 9-10 with NaOH solution to obtain the sludge heavy metal extractant.

   Another technical solution of the present invention is to apply the above-mentioned sludge heavy metal extractant for sludge treatment, which is specifically implemented according to the following steps:

   step 1, the sludge is pre-shrunk treatment, so that the water content of the sludge will be below 97%, to obtain concentrated sludge;

   step 2, adding sludge heavy metal extractant to the concentrated sludge obtained in step 1, according to the ratio of 0.7 to 0.9 tons of sludge heavy metal extractant per 100 tons of concentrated sludge;

  Step 3, conditioning, that is, the concentrated sludge in Step 2 and the sludge heavy metal extractant are thoroughly mixed. The temperature of the sludge in the conditioning process can be between 10°C and 35°C, and it can be stirred at a uniform speed;

'Step 4, the mixture after conditioning in step 3 stays in the conditioning tank for 30 to 40 minutes;

  Step 5, the mixture after the reaction in Step 4 is deeply dehydrated by a plate and frame filter press to bring the water content to 55% to 60%, and the sludge after heavy metal extraction is obtained.

The beneficial effects of the present invention are that it solves the problems of long treatment period, high operating cost and poor heavy metal removal effect in the prior art when carrying out sludge heavy metal removal and dehydration treatment. The sludge heavy metal extractant prepared by the present invention is used. After sludge treatment, the content of heavy metal elements in the sludge of municipal sewage treatment plants can be greatly reduced, and the heavy metal content requirements of the agricultural standards for sludge can be met.
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