CN113880637B

CN113880637B - Preparation method for quickly converting sludge into nutrient soil

Info

Publication number: CN113880637B
Application number: CN202111194236.XA
Authority: CN
Inventors: 蔡冬清; 王冬芳; 李若晗; 吴庆川; 田登峰; 许贺
Original assignee: Donghua University
Current assignee: Donghua University
Priority date: 2021-10-13
Filing date: 2021-10-13
Publication date: 2022-09-27
Anticipated expiration: 2041-10-13
Also published as: CN113880637A

Abstract

A preparation method for quickly converting sludge into nutrient soil belongs to the technical field of preparation of plant nutrient soil. Sequentially adding potassium hydroxide, calcium peroxide and aluminum ash into the sludge, and fully stirring for 10-30 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid; adding potassium carbonate into the high-activity sludge A, fully stirring at room temperature, and effectively passivating the cationic heavy metal in the high-activity sludge A to obtain sludge B after heavy metal passivation; sequentially adding attapulgite, sawdust powder and vermiculite into the sludge B, and fully stirring at room temperature to obtain nutrient soil C; sequentially adding monoammonium phosphate, ammonium sulfate and ammonium bicarbonate into the nutrient soil C, and fully stirring at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium. Macromolecular organic matters in the sludge are converted into micromolecular fulvic acid through a catalytic degradation technology, and heavy metals in the sludge are passivated by adding carbonate, attapulgite, sawdust powder, monoammonium phosphate, vermiculite and the like, so that the air permeability and the nutritional value of the nutritional soil are improved.

Description

Preparation method for quickly converting sludge into nutrient soil

Technical Field

The invention belongs to the technical field of preparation of plant nutrient soil, and particularly relates to a preparation method for quickly converting sludge into nutrient soil.

Background

With the continuous, rapid and stable development of economy in China, the scale of urban sewage treatment in China is increased day by day, and the sludge yield is correspondingly increased. In order to improve the water quality and ecological environment of rivers, lakes and oceans, the monitoring strength of China on sludge discharge is also increased. According to statistics, the sludge yield of China in 2019 exceeds 6000 million tons (calculated by the water content of 80%), and the annual sludge yield of China in 2025 is predicted to break through 9000 million tons. However, since the 'heavy water and light mud' has long been used in China, the sludge treatment is not synchronously promoted with the sewage treatment, the problem of the sludge treatment cannot be effectively solved, and the situation is very severe.

Currently, the sludge treatment commonly used in China mainly comprises drying, agriculture, incineration and landfill, wherein the drying technology mainly comprises filter pressing, flocculation concentration, anaerobic digestion, high-temperature aerobic fermentation, heat drying and the like. Dried sludge is usually treated by land utilization, incineration or landfill, but these treatment methods are currently hindered to different degrees. The requirement of land utilization on sludge quality is high, and heavy metals and other toxic and harmful substances in sludge often exceed the standard; because the water content of the sludge is high, the sludge needs to be subjected to complex treatment before incineration, and the method is time-consuming and labor-consuming, has high energy consumption, and cannot realize ecological environmental protection; the embarrassment situation that the sanitary landfill can be buried without land usually occurs, and the problem cannot be solved fundamentally. Therefore, development of a novel sludge reduction and resource utilization technology is urgently needed.

The invention content is as follows:

aiming at the problems, the invention provides a preparation method for quickly converting sludge into nutrient soil, which converts macromolecular organic matters in the sludge into micromolecular fulvic acid through a catalytic degradation technology, and adds carbonate, attapulgite, sawdust powder, monoammonium phosphate, vermiculite and the like to passivate heavy metals in the sludge, thereby improving the air permeability and the nutritional value of the nutrient soil.

The invention is realized by the following technical scheme, and the preparation method for quickly converting sludge into nutrient soil comprises the following steps:

step 1: sequentially adding potassium hydroxide, calcium peroxide and aluminum ash into the sludge, and fully stirring for 10-30 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid;

step 2: adding potassium carbonate into the high-activity sludge A, fully stirring for 10-30 minutes at room temperature, and effectively passivating the cationic heavy metal in the high-activity sludge A to obtain sludge B after heavy metal passivation;

and step 3: sequentially adding attapulgite, sawdust powder and vermiculite into the sludge B, and fully stirring for 10-30 minutes at room temperature to obtain nutrient soil C with good air permeability;

and 4, step 4: sequentially adding monoammonium phosphate, ammonium sulfate and ammonium bicarbonate into the nutrient soil C, and fully stirring for 10-30 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

According to the invention, the sludge is subjected to resource utilization, the sludge is rapidly treated by a catalytic degradation technology, organic matters of macromolecules in the sludge are converted into micromolecular fulvic acid, heavy metals in the sludge are passivated by adding carbonate, and the air permeability and the nutritional value of the nutrient soil are improved by adding attapulgite, wood dust powder, monoammonium phosphate, vermiculite and the like, so that the problem of resource utilization of the sludge is fundamentally solved. Macromolecular organic matters in the sludge are converted into micromolecular fulvic acid through a catalytic degradation technology, and heavy metals in the sludge are passivated by adding carbonate, attapulgite, sawdust powder, monoammonium phosphate, vermiculite and the like, so that the air permeability and the nutritional value of the nutritional soil are improved.

Drawings

FIG. 1 is a graph showing the change in fulvic acid content of highly activated sludge A in example 3 of the present invention.

FIG. 2 is a graph showing the change in the soluble lead and cadmium contents before and after the sludge passivation in example 3 of the present invention.

Detailed Description

Example 1:

step 1: sequentially adding 10g of potassium persulfate, 10g of potassium hydroxide, 10g of calcium peroxide and 20g of 100-mesh aluminum ash into 400g of sludge with the water content of 80%, and fully stirring for 10 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid;

step 2: adding 10g of potassium carbonate into 400g of high-activity sludge A, and fully stirring for 10 minutes at room temperature to effectively passivate cationic heavy metals in the high-activity sludge A, so as to obtain sludge B after the passivation of the heavy metals;

and step 3: sequentially adding 20g of attapulgite with colloid grade and 100 meshes, 20g of sawdust powder with 20 meshes and 10g of vermiculite into 400g of sludge B, and fully stirring for 10 minutes at room temperature to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 20g of monoammonium phosphate, 20g of ammonium sulfate and 20g of ammonium bicarbonate into 400g of nutrient soil C, and fully stirring for 10 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

Example 2:

step 1: sequentially adding 12g of potassium persulfate, 12g of potassium hydroxide, 12g of calcium peroxide and 24g of 120-mesh aluminum ash into 400g of sludge with the water content of 82%, and fully stirring for 14 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid;

step 2: adding 12g of potassium carbonate into 400g of high-activity sludge A, fully stirring for 14 minutes at room temperature, and effectively passivating the cationic heavy metal in the high-activity sludge A to obtain sludge B after the heavy metal is passivated;

and step 3: sequentially adding 22g of attapulgite with colloid grade and 120 meshes, 22g of sawdust powder with 24 meshes and 12g of vermiculite into 400g of sludge B, and fully stirring for 14 minutes at room temperature to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 22g of monoammonium phosphate, 22g of ammonium sulfate and 22g of ammonium bicarbonate into 400g of nutrient soil C, and fully stirring for 14 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

Example 3:

step 1: sequentially adding 14g of potassium persulfate, 14g of potassium hydroxide, 14g of calcium peroxide and 28g of 140-mesh aluminum ash into 480g of sludge with the water content of 84%, and fully stirring at room temperature for 18 minutes to obtain high-activity sludge A rich in fulvic acid;

and 2, step: adding 14g of potassium carbonate into 480g of the high-activity sludge A, and fully stirring for 18 minutes at room temperature to effectively passivate cationic heavy metals in the high-activity sludge A to obtain sludge B after the passivation of the heavy metals;

and step 3: sequentially adding 24g of attapulgite with colloid grade and 140 meshes, 24g of sawdust powder with 28 meshes and 14g of vermiculite into 480g of sludge B, and fully stirring for 18 minutes at room temperature to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 24g of monoammonium phosphate, 24g of ammonium sulfate and 24g of ammonium bicarbonate into 480g of nutrient soil C, and fully stirring for 18 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

Fig. 1 is a graph showing the change of fulvic acid content in the high-activity sludge a in the present example, and it can be seen from the graph that: the fulvic acid content gradually increases with time. FIG. 2 is a graph showing the change of soluble lead and cadmium contents before and after the sludge passivation in this example, and it can be seen from the graph that: the soluble lead and cadmium levels before and after passivation are significantly less.

Example 4:

step 1: sequentially adding 18g of potassium persulfate, 18g of potassium hydroxide, 18g of calcium peroxide and 35g of 160-mesh aluminum ash into 550g of sludge with the water content of 86%, and fully stirring at room temperature for 25 minutes to obtain high-activity sludge A rich in fulvic acid;

step 2: adding 18g of potassium carbonate into 550g of high-activity sludge A, fully stirring for 25 minutes at room temperature, and effectively passivating the cationic heavy metal in the high-activity sludge A to obtain sludge B after heavy metal passivation;

and step 3: sequentially adding 28g of attapulgite with colloid grade and 180 meshes, 28g of sawdust powder with 35 meshes and 18g of vermiculite into 550g of sludge B, and fully stirring at room temperature for 25 minutes to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 28g of monoammonium phosphate, 28g of ammonium sulfate and 28g of ammonium bicarbonate into 550g of nutrient soil C, and fully stirring for 25 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

Example 5:

step 1: sequentially adding 20g of potassium persulfate, 20g of potassium hydroxide, 20g of calcium peroxide and 40g of 200-mesh aluminum ash into 600g of sludge with the water content of 90%, and fully stirring for 30 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid;

step 2: adding 20g of potassium carbonate into 600g of high-activity sludge A, fully stirring for 30 minutes at room temperature, and effectively passivating the cationic heavy metal in the high-activity sludge A to obtain sludge B after the heavy metal is passivated;

and step 3: sequentially adding 30g of attapulgite with colloid grade and 200 meshes, 30g of sawdust powder with 40 meshes and 20g of vermiculite into 600g of sludge B, and fully stirring for 10 minutes at room temperature to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 30g of monoammonium phosphate, 30g of ammonium sulfate and 30g of ammonium bicarbonate into 600g of nutrient soil C, and fully stirring for 10-30 minutes at room temperature to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.

Claims

1. A preparation method for quickly converting sludge into nutrient soil is characterized by comprising the following steps:

step 1: sequentially adding 10-20g of potassium persulfate, 10-20g of potassium hydroxide, 10-20g of calcium peroxide and 20-40g of 100-mesh 200-mesh aluminum ash into 600g of sludge with the water content of 80-90%, and fully stirring for 10-30 minutes at room temperature to obtain high-activity sludge A rich in fulvic acid;

step 2: adding 10-20g of potassium carbonate into 400-600g of high-activity sludge A, and fully stirring at room temperature for 10-30 minutes to effectively passivate cationic heavy metal in the high-activity sludge A to obtain sludge B after heavy metal passivation;

and step 3: sequentially adding 100-200 meshes of 20-30g of attapulgite, 20-40 meshes of 20-30g of sawdust powder and 10-20g of vermiculite into 400-600g of sludge B, and fully stirring at room temperature for 10-30 minutes to obtain nutrient soil C with good air permeability;

and 4, step 4: and sequentially adding 20-30g of monoammonium phosphate, 20-30g of ammonium sulfate and 20-30g of ammonium bicarbonate into 400-600g of nutrient soil C, and fully stirring at room temperature for 10-30 minutes to obtain the nutrient soil rich in nitrogen, phosphorus and potassium.