Sewage treatment agent and preparation method thereof

Abstract

The invention relates to the technical field of sewage treatment, and discloses a sewage treatment agent, which comprises, by weight, 1-5 parts of activated calcium chloride, 1-5 parts of strontium chloride and 0.5-3 parts of barium acetate. The sewage treatment agent of the invention has a removal rate of sulfate in sewage of 60-78%; secondly, the amount of the sewage treatment agent is small, the removal means is simple and the cost is low, and there is no secondary pollution, and the sewage treatment agent belongs to an environmentally friendly sewage treatment agent.

Description

Technical Field

[0001] The invention relates to the technical field of sewage treatment, and in particular to a sewage treatment agent and a preparation method thereof. Background Art

[0002] Mine water pollution refers to the phenomenon that mining industrial wastewater and domestic sewage containing various pollutants and toxic substances change their normal composition after being discharged into the water body, exceeding the self-purification capacity of the water, thereby deteriorating the water body and destroying the original use of the water body. Acidic wastewater pollution, heavy metal pollution, and nutrient enrichment caused by mining emissions are all causes of mine water pollution. Among them, acidic wastewater pollution is a common pollution phenomenon in mines, especially in the mining of sulfide deposits and coal seams, which has the greatest degree of harm.

[0003] The main component of acidic wastewater is sulfate, including calcium sulfate, iron sulfate and copper sulfate. Sulfate discharged into the water will cause water acidification through desulfurization, and will be reduced to produce hydrogen sulfide gas under anaerobic conditions, causing environmental odor, poisoning microorganisms and inhibiting the self-purification ability of natural water bodies, making it difficult to degrade and remove pollutants. In the existing technology, barium salt precipitation method needs to be used for CO3 removal during the treatment process. 2- The removal of interfering factors is a cumbersome procedure; the sulfate removal rate in the calcium salt precipitation method is low and cannot meet the emission standards; the membrane in the reverse osmosis membrane method is expensive and has a short service life, and cannot be applied to wastewater treatment with a high degree of pollution.

[0004] To this end, Chinese patent document CN103347823A discloses "sulfate removal from a waste water stream with recycling". This invention uses reverse osmosis or nanofiltration technology and coagulant precipitation to remove sulfate from a water source. By combining the reverse osmosis method with the precipitation method, the problems of high membrane cost, short service life and limited sewage pollution in the reverse osmosis membrane method are solved to a certain extent. However, there are still problems in the coagulant precipitation step, such as low sulfate removal rate, large amount of reagents and complicated removal means. Summary of the invention

[0005] The present invention aims at the problems of low sewage removal rate, large dosage of reagents and complicated removal means in the prior art, and proposes a sewage treatment agent and a preparation method. The sewage treatment agent prepared by the method of the present invention has a small dosage during use, a high sulfate removal rate and a simple removal means, and is applied to coal mine sewage, avoiding secondary pollution and greatly reducing the sewage treatment cost.

[0006] To achieve the above technical purpose, the present invention provides a sewage treatment agent, which comprises, by weight, 1-5 parts of activated calcium chloride, 1-5 parts of strontium chloride and 0.5-3 parts of barium acetate.

[0007] The sewage treatment agent includes, by weight, 3 parts of activated calcium chloride, 2 parts of strontium chloride and 1 part of barium acetate.

[0008] The purity of the activated calcium chloride, strontium chloride or barium acetate is 90-100%, preferably 98%.

[0009] The activated calcium chloride is prepared by mixing ethanol solution as an activator into calcium chloride and then activating it; preferably, the ethanol solution is an ethanol aqueous solution with a mass fraction of 90-95%; preferably, the mass of the ethanol solution accounts for 20-24% of the mass of calcium chloride; preferably, the activation time is 60-80 minutes.

[0010] The present invention also provides a method for preparing a sewage treatment agent, comprising weighing activated calcium chloride, strontium chloride and barium acetate according to the above weight parts, dissolving them in water, and obtaining the sewage treatment agent.

[0011] The weight of the mixture of activated calcium chloride, strontium chloride and barium acetate in the sewage treatment agent accounts for 10-20% of the weight of water.

[0012] The weight of the mixture of activated calcium chloride, strontium chloride and barium acetate in the sewage treatment agent accounts for 15% of the weight of water.

[0013] The temperature during the preparation of the sewage treatment agent is 20-30°C, preferably 25°C.

[0014] The dissolution process further includes stirring, and the stirring time is 10-60 minutes; preferably, the stirring time is 45 minutes.

[0015] The technical solution of the present invention has the following beneficial effects:

[0016] (1) The present invention provides a sewage treatment agent, comprising 1-5 parts of activated calcium chloride, 1-5 parts of strontium chloride and 0.5-3 parts of barium acetate. The present invention unexpectedly discovered that the sewage treatment agent obtained by using activated calcium chloride, strontium chloride and barium acetate in a specific weight ratio greatly improves the removal rate of sulfate in sewage, and the removal rate reaches 60-78%; secondly, the amount of input is small, the removal method is simple and low-cost, and there is no secondary pollution. Compared with the cost of 15-25 yuan / ton for treating sewage with reverse osmosis membrane in the prior art, the treatment cost of the present invention is 5-8 yuan / ton, and the cost reduction rate reaches 45-80%, which greatly reduces the cost and creates huge benefits for society. The sewage treatment agent of the present invention is used for sewage treatment in coal mines. The substances produced after treatment, along with the sedimentation of coal slime, have no secondary pollution, and are an environmentally friendly sewage treatment agent.

[0017] (2) The present invention provides a method for preparing a sewage treatment agent, wherein activated calcium chloride, strontium chloride and barium acetate are weighed in proportion, and are placed in a container with water to dissolve to obtain a sewage treatment agent. The preparation method is simple, and the dissolved substances can be directly added to sewage without further treatment, which greatly simplifies the sewage treatment process and saves time and labor costs.

[0018] (3) The present invention provides a method for preparing a sewage treatment agent, wherein the sewage treatment agent comprises 1-5 parts of activated calcium chloride, 1-5 parts of strontium chloride and 0.5-3 parts of barium acetate, preferably 3 parts of activated calcium chloride, 2 parts of strontium chloride and 1 part of barium acetate; the weight of the mixture of activated calcium chloride, strontium chloride and barium acetate in the sewage treatment agent accounts for 10%-20% of the weight of water, preferably, the weight ratio is 15%. The sewage treatment agent prepared under the above conditions has a further improved sewage treatment effect, thereby further reducing the sewage treatment cost. DETAILED DESCRIPTION

[0019] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0020] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0021] Example 1

[0022] The present embodiment provides a sewage treatment agent, and the specific preparation method is: at 25°C, weigh 0.3 kg of activated calcium chloride (purity 98%), 0.2 kg of strontium chloride (purity 98%), and 0.1 kg of barium acetate (purity 98%), put them into a reaction tank added with 4 kg of water to dissolve, stir for 45 minutes, and obtain the sewage treatment agent.

[0023] Preparation method of activated calcium chloride: 22g of 95% ethanol solution is mixed into 1kg of calcium chloride, and activated for 65min to prepare activated calcium chloride.

[0024] Comparative Example 1

[0025] This comparative example provides a sewage treatment agent, which differs from Example 1 in that "0.3 kg of activated calcium chloride (purity 98%), 0.2 kg of strontium chloride (purity 98%), and 0.1 kg of barium acetate (purity 98%)" are changed to "0.6 kg of activated calcium chloride (purity 98%)", and the rest of the preparation method is the same as that of Example 1.

[0026] Comparative Example 2

[0027] This comparative example provides a sewage treatment agent, which differs from Example 1 in that "0.3 kg of activated calcium chloride (purity 98%), 0.2 kg of strontium chloride (purity 98%), and 0.1 kg of barium acetate (purity 98%)" are changed to "0.6 kg of strontium chloride (purity 98%)", and the rest of the preparation method is the same as that of Example 1.

[0028] Comparative Example 3

[0029] This comparative example provides a sewage treatment agent, which differs from Example 1 in that "0.3 kg of activated calcium chloride (purity 98%), 0.2 kg of strontium chloride (purity 98%), and 0.1 kg of barium acetate (purity 98%)" are changed to "0.6 kg of barium acetate (purity 98%)", and the rest of the preparation method is the same as that of Example 1.

[0030] Experimental Example 1

[0031] This experimental example measured the removal effect of the sewage treatment agents of Example 1 and Comparative Examples 1-3, and the specific steps are as follows:

[0032] 1000mL of raw water from a coal mine was taken to determine the sulfate content in the wastewater. 5mL of a wastewater treatment agent was added, stirred for 2 minutes, and the sulfate content in the supernatant was determined after settling for 5 minutes. The results are shown in Table 1 below.

[0033] The sulfate content was determined according to the General Method for Determination of Sulfate in Chemical Reagents (GB 9728-1988).

[0034] Table 1 Determination results of sulfate content

[0035]

[0036] The sewage discharge standard of Shandong Province is that the sulfate content in sewage is below 650 mg / L. As shown in Table 1, the sulfate content in the sewage treated with the sewage treatment agent prepared in Comparative Examples 1-3 is 855-876 mg / L, and the removal rate is 0-9.8%, while the sulfate content in the sewage treated with the sewage treatment agent prepared in Example 1 is 197 mg / L, which meets the Shandong Provincial Standard, and the removal rate is 77.5%. Therefore, the sewage treatment agent of the present invention greatly reduces the sulfate content in sewage, and the sewage removal rate can reach 60-78%.

[0037] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A sewage treatment agent, characterized in that: The sewage treatment agent is composed of 1-5 parts of activated calcium chloride, 1-5 parts of strontium chloride and 0.5-3 parts of barium acetate in parts by weight; The activated calcium chloride is prepared by mixing ethanol solution as an activator into calcium chloride and then activating it; The sewage treatment agent is used for treating sewage in coal mines.

2. The sewage treatment agent according to claim 1, characterized in that In terms of weight, the sewage treatment agent consists of 3 parts of activated calcium chloride, 2 parts of strontium chloride and 1 part of barium acetate.

3. The sewage treatment agent according to claim 1 or 2, characterized in that: The purity of the activated calcium chloride, strontium chloride or barium acetate is 90-100%.

4. The sewage treatment agent according to claim 3, characterized in that: The purity of the activated calcium chloride, strontium chloride or barium acetate is 98%.

5. The sewage treatment agent according to claim 1, characterized in that: The ethanol solution is an ethanol aqueous solution with a mass fraction of 90-95%.

6. The sewage treatment agent according to claim 5, characterized in that: The mass of the ethanol solution accounts for 20-24% of the mass of calcium chloride.

7. The sewage treatment agent according to claim 5, characterized in that: The activation time is 60-80 minutes.

8. A method for preparing the sewage treatment agent according to any one of claims 1 to 7, characterized in that: The method comprises weighing activated calcium chloride, strontium chloride and barium acetate according to the above weight proportions, dissolving them in water, and obtaining a sewage treatment agent.

9. The method for preparing a sewage treatment agent according to claim 8, characterized in that: The weight of the mixture of activated calcium chloride, strontium chloride and barium acetate in the sewage treatment agent accounts for 10-20% of the weight of water.

10. The method for preparing a sewage treatment agent according to claim 8 or 9, characterized in that: The weight of the mixture of activated calcium chloride, strontium chloride and barium acetate in the sewage treatment agent accounts for 15% of the weight of water.

11. The method for preparing a sewage treatment agent according to claim 8, characterized in that: The temperature during the preparation of the sewage treatment agent is 20-30°C.

12. The method for preparing a sewage treatment agent according to claim 11, characterized in that: The temperature during the preparation of the sewage treatment agent is 25°C.

13. The method for preparing a sewage treatment agent according to claim 8, characterized in that: The dissolving process further includes stirring, and the stirring time is 10-60 minutes.

14. The method for preparing a sewage treatment agent according to claim 13, characterized in that: The stirring time is 45 min.

15. A sewage treatment agent prepared according to the method for preparing a sewage treatment agent according to any one of claims 8 to 14.

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