CN101337706A - Method for treating water containing tetracycline antibiotics by using powdered activated carbon - Google Patents

Abstract

The invention belongs to the field of pollution prevention and control and discloses a method for treating a water body containing tetracycline antibiotics by using powdered activated carbon. The method comprises the steps of adding powdered activated carbon and the water body polluted by tetracycline antibiotics into a container, performing treatment by using the method of intermittent churning for a proper time, and then removing powdered activated carbon from the water body. The method has the advantages of simple operation, low cost, less time consumption, wide application area, safety and friendliness to the environment, as well as adaptability to industrialized application.

Description

Method for treating water containing tetracycline antibiotics by using powdered activated carbon

technical field

The invention belongs to the field of pollution prevention and control, and relates to a method for treating water containing tetracycline antibiotics by using powdered activated carbon.

Background technique

Tetracycline antibiotics are broad-spectrum antibacterial substances isolated from the culture fluid of the actinomycetes Streptococcus aureus, etc. Has a good inhibitory effect.

Because tetracyclines are highly effective and broad-spectrum, antibiotics are commonly used to kill pathogens at home and in medical institutions. In particular, there are many kinds of antibiotics used in medical institutions and they are used intensively, but the metabolism efficiency of such drugs in the human body is very low. The treatment efficiency of antibiotics is limited. Today's reliance on and misuse of antibiotics in home health care and medical settings exacerbates the leakage of these antibiotics into the environment.

Tetracycline antibiotics are also widely used in the fields of agriculture and fish farming. Adding a certain dose of tetracycline antibiotics to feed and aquaculture water can prevent diseases and promote the growth of poultry, livestock and aquatic products. However, the absorption efficiency of tetracycline antibiotics in the digestive system of animals is very low, and up to 50-80% of tetracycline antibiotics are excreted through feces without being metabolized. Farm food residues, animal manure, organic waste, etc. are usually applied to the farmland as organic fertilizers after staying in the sewage tank for a period of time and undergoing biological treatment. The antibiotics carried by these organic fertilizers accumulate continuously after entering the soil. Over time, these antibiotic pollutants will seep into the groundwater due to leaching in the soil, and may also enter the surface water system with surface runoff or soil erosion. In addition, when tetracycline antibiotics (especially oxytetracycline) are used in aquaculture farms, such compounds will accumulate in water sediments and spread to other places with the flow of water.

Another cause of high concentrations of tetracycline antibiotics in the environment is the discharge of wastewater from the production of these antibiotics. At present, most antibiotic drugs, including tetracyclines, are mainly produced in several developing countries. Taking China as an example, antibiotic products cover 70 varieties, the output accounts for about 20% to 30% of the world's total, and there are about 300 production enterprises. The main production process of this type of drug is biosynthesis, which produces refractory high-concentration organic wastewater with complex components, high chroma, high biological toxicity, and various inhibitory substances, with COD as high as 10,000-40,000 mg/L. General physical and chemical treatment methods are difficult to effectively remove high-concentration organic pollutants including tetracycline in wastewater. In addition, residual antibiotics make further biological treatment of wastewater more difficult and inefficient. Due to the above reasons, a large part of antibiotic production enterprises cannot achieve stable and up-to-standard discharge, seriously endangering the water environment. With the development of the antibiotic industry, antibiotic production wastewater has become one of the serious pollution sources.

Academia used to think that tetracycline compounds would be easily degraded after entering the environment, but recent studies have shown that tetracycline will remain stable for a long time after entering the soil or water sediment for several months or even a year. The nature of the existence will make its own concentration accumulate continuously with the input of external pollution sources. These non-metabolized antibiotics will pollute surface water, groundwater and soil through surface runoff or seepage.

The emergence of antibiotic compounds in soil and water not only poses a threat to the local microbial community and destroys the balance between the original microbial community; Drug resistance refers to the tolerance and resistance of organisms (especially pathogenic microorganisms) to antibiotics and other drugs. Tetracycline products are commonly used antibiotics for humans and animals, and they have a broad spectrum. Therefore, tetracyclines can cause a wide variety of pathogens to induce drug resistance after entering the environment. In addition, microorganisms can carry out gene exchange through plasmids (plasmids) containing resistance genes, so that drug resistance can spread between the same species or different strains. Since the advent of tetracycline antibiotics for more than 60 years, as many as 38 tetracycline resistance factors (tetR) have been found in various microorganisms. Studies have shown that antibiotic resistance genes have been detected in a variety of environmental samples including river sediments, irrigation water, activated sludge from sewage treatment plants, sewage ponds near farms, and groundwater.

The emergence and spread of pathogen drug resistance has brought serious consequences to human society: on the one hand, the effect of existing drugs is reduced or even ineffective after being infected by drug-resistant pathogens, which makes the infected people face the dilemma of disease treatment; on the other hand, this The emergence of the phenomenon forces scientific research and medical institutions to spend a lot of manpower to physically develop new drugs, which brings a heavy burden to the society.

The continuous spread of antibiotic-resistant pathogens in the environment is a daunting issue of increasing global concern and must be addressed. To deal with the production wastewater of tetracycline antibiotics and the water containing such substances is an effective measure to deal with this dilemma. The current treatment methods of antibiotic wastewater The treatment methods of antibiotic wastewater include: biological treatment methods, physical and chemical treatment methods, and combined treatment of various methods.

Although the biological treatment method of antibiotic pharmaceutical wastewater has disadvantages such as large area, foam, and difficult to remove chroma, due to economic considerations, various processes of biological treatment methods are still the main choice at present. The aerobic treatment method has a good removal effect on COD, but the aerobic biochemical treatment method generally requires high dilution of the water body, and pretreatment of the wastewater such as pH, so the energy consumption is relatively high, and the tetracycline wastewater itself has biological Toxicity will inhibit the activity of aerobic bacteria, so the method has high operating costs and unsatisfactory treatment effect. The main metabolic role in the anaerobic treatment process is acid-producing bacteria and methanogenic bacteria, which have relatively different biological characteristics. Among them, acid-producing bacteria grow fast and have low sensitivity to poisons, which are usually used as the first stage of the anaerobic process. In order to improve the biodegradability of wastewater, weaken the inhibitory effect of antibiotics in wastewater on methanogens, and then ensure a stable treatment effect in the methanogenic stage of the composite anaerobic treatment system. However, the effluent treated by a separate anaerobic method still has high COD, and it is difficult to make the effluent reach the standard. Compared with the separate operation of the above two methods, the combined anaerobic-aerobic treatment method has obvious advantages in improving the biodegradability, impact resistance, investment cost, and treatment effect of wastewater.

However, due to the complex composition of tetracycline antibiotic production wastewater, high organic content, and a small amount of residual tetracycline antibiotics, when biochemical treatment is used, the strong inhibitory effect of residual antibiotics on microorganisms can lead to complex wastewater treatment processes, high costs and unstable results. Moreover, studies have shown that in a typical activated sludge treatment (biological treatment) unit of a water treatment plant, as the concentration of tetracycline in the influent increases, the concentration of tetracycline in the effluent increases and the amount of resistant microorganisms increases at the same time, that is, using biological methods. Tetracycline antibiotics production wastewater has the potential danger of screening drug-resistant pathogenic organisms and allowing them to flow into the environment with the effluent.

The physical and chemical treatment methods currently used mainly include chemical oxidation, coagulation, reverse osmosis, membrane treatment, photocatalytic degradation and adsorption. In the chemical treatment of antibiotic wastewater, the use of ozone and chlorine oxidation can increase the BOD/COD ratio of antibiotic wastewater, and at the same time have a better removal rate for COD, but there are oxidizing reagents used in the application process of chemical oxidation methods Low efficiency, high operating costs and other unfavorable factors. The coagulation treatment method has poor applicability to acid tetracycline wastewater, and the pH value of the wastewater needs to be adjusted in advance, and the waste residue generated by a large amount of flocculant is likely to cause secondary pollution. Reverse osmosis and membrane separation technology have a high treatment efficiency for COD of antibiotic pharmaceutical wastewater, but their operating costs are relatively high. Currently, this technology is rarely put into actual operation. In addition, the experimental research on the photocatalytic degradation of tetracycline production wastewater using ZnO and _TiO2 has been reported, but its actual operation effect remains to be investigated.

Among them, the adsorption method is highly respected in the field of water treatment for its cost-effectiveness, simple operation and stable operation. Activated carbon has been widely used in many production fields as the most common adsorbent in gas phase and water phase treatment since its invention in the 20th century. However, there is no report on the application of activated carbon to the pollution control of tetracycline antibiotics.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide an economical, efficient, easy-to-operate, stable-running, environmentally safe and friendly method for treating water containing tetracycline antibiotics by using powdered activated carbon.

This technology is aimed at water bodies polluted by tetracycline antibiotics (including but not limited to tetracycline antibiotic production wastewater, surface water and groundwater, hereinafter referred to as water).

The purpose of the present invention is achieved through the following technical measures:

Utilize powder activated carbon to process the method for containing tetracycline antibiotic water body, this method adopts following steps:

a. Add powdered activated carbon and water containing tetracycline antibiotics into the container, and use intermittent stirring for an appropriate time;

b. Removal of powdered activated carbon from water bodies.

The method, wherein the activated carbon is a powder with a particle size between 100-200 mesh.

The method, wherein the intermittent stirring is once every 6-9 hours, and the duration of each stirring is 5-10 minutes.

Said method, wherein the time for intermittent stirring is 24 to 48 hours.

Said method, wherein under the condition that the concentration of tetracycline antibiotics in the water body is not greater than 1mM, the mass ratio of the amount of powdered activated carbon to the water body containing tetracycline antibiotics is 1:400-1000.

The method, wherein under the condition that the concentration of tetracycline antibiotics in the water body is not greater than 1mM, the mass ratio of the amount of powdered activated carbon to the water body containing tetracycline antibiotics is 1:400-800.

The method, wherein under the condition that the concentration of tetracycline antibiotics in the water body is not greater than 1mM, the mass ratio of the amount of powdered activated carbon to the water body containing tetracycline antibiotics is 0.25%.

The method, wherein the method for removing the powdered activated carbon from the water body in step b is to use a 400-mesh screen to separate the treated water from the powdered activated carbon.

This method performs the reaction at ambient temperature.

The present invention is further described below in conjunction with accompanying drawing of description:

As shown in Figure 1, the water 1 polluted by tetracycline antibiotics and powdered activated carbon 2 are added in the premix tank 3. In the premix tank, a mechanical stirring device 4 is used to add the added water and powder The activated carbon mixture was stirred intermittently (every 8 hours for 5-10 minutes), and treated for 36-48 hours. Then, the premixed and balanced water and powdered activated carbon mixture 5 are passed through a pipeline 6 with a valve and then through a 400-mesh screen 7 , and the purified water 8 enters a collection tank 9 .

During the treatment process, the amount of powdered activated carbon added is determined by the quality of the water to be treated and the concentration of tetracycline antibiotics in it. For the water body whose concentration of tetracycline antibiotics is not more than 1mM, the addition ratio of the powdered activated carbon is preferably 1/400 of the water body weight. Intermittent mechanical stirring for about 5-10 minutes every 8 hours, treatment for 36 hours, the adsorption removal efficiency reaches 100%.

This method performs the reaction at ambient temperature.

Beneficial effects of the present invention:

This technology targets water contaminated with tetracycline antibiotics. Tetracycline antibiotic pollutants can be effectively removed by adding powdered activated carbon to water and stirring intermittently, and then filtering and separating the powdered activated carbon. Under the conditions that the initial concentration of tetracycline antibiotics is 1mM, and the addition ratio of powder activated carbon is about 1/400 of the water body weight, the removal rate of tetracycline antibiotic pollutants is nearly 100%. The method is suitable for the treatment of water bodies polluted by tetracycline antibiotics (including but not limited to tetracycline antibiotic production wastewater, surface water and groundwater), and can also be used for small-scale drinking water purification treatment for individual users. The method has no special requirements on the operating site, and has low requirements on equipment and operating conditions, is simple and easy to implement, does not need to add other chemicals, and has a short operating time, is conducive to industrial application, and is safe and friendly to the environment. Moreover, the treatment effect of the method is basically not affected by the common substances in the tetracycline antibiotic production wastewater.

Description of drawings

Fig. 1 is a schematic diagram of the method of using powdered activated carbon to treat water containing tetracycline antibiotics in the present invention.

In the figure, 1 is water polluted by tetracycline antibiotics, 2 is powdered activated carbon, 3 is a premix tank, 4 is a stirring device, 5 is a premixed water and activated carbon mixture, 6 is a pipeline with a valve, 7 is a Separation screen, 8 is the filtered water body, and 9 is a collection tank.

Detailed ways

The present invention is described further below by embodiment.

Example 1

Ordinary tap water is mixed with tetracycline to make the concentration reach 1mM, hereinafter referred to as polluted water.

Combined with the accompanying drawings in the description, add polluted water 1 and powdered activated carbon 2 into the premix tank 3, the mass ratio of powdered activated carbon to polluted water is 1:800, and in the premix tank, a mechanical stirring device 4 is used , with intermittent mechanical stirring for about 5-10 minutes every 8 hours for 36 hours. Then the premixed water and powdered activated carbon mixture 5 are passed through a 400-mesh screen 7 through a pipeline 6 with a valve, and the filtered water 8 enters a collecting tank 9 . The above treatments were all carried out at ambient temperature.

Ordinary tap water contains tetracycline up to 1mM, add powdered activated carbon according to 1/800 of the water quality, stir intermittently for 5-10 minutes every 8 hours, after 36 hours, the concentration of tetracycline in the water after filtering through the screen is 0.04mM, and the removal rate is 96% .

Example 2

Ordinary tap water was mixed with tetracycline so that the concentration reached 1mM.

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM, add powdered activated carbon according to 1/400 of the water mass (to investigate the treatment effect when the amount of powdered activated carbon is increased), stir intermittently for 5-10 minutes every 8 hours, continue for 36 hours, and filter through a sieve The removal rate of tetracycline concentration < 0.1μM in the water body is nearly 100%.

Example 3

Ordinary tap water was mixed with tetracycline to make the concentration reach 1mM, and urea was added to make the concentration 126mg/L (to investigate the influence of common components in tetracycline antibiotics production wastewater on the treatment effect of powdered activated carbon).

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM, and urea 126mg/L. Add powdered activated carbon according to 1/400 of the water quality, and stir intermittently for 5-10 minutes every 8 hours. After 36 hours, the tetracycline in the water after filtering through the screen The removal rate of element concentration <0.1μM is nearly 100%.

Example 4

Ordinary tap water was mixed with tetracycline to make the concentration reach 1mM, and NaH ₂ PO ₄ was added to make the concentration 52mg/L (to investigate the influence of common components in tetracycline antibiotic production wastewater on the treatment effect of powder activated carbon).

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM, and NaH ₂ PO ₄ 52mg/L. Add powdered activated carbon according to 1/400 of the water quality, and stir intermittently for 5-10 minutes every 8 hours. After 36 hours, the water body filtered through the screen The removal rate of tetracycline concentration < 0.1μM is nearly 100%.

Example 5

Ordinary tap water was mixed with tetracycline to make the concentration 1mM, and glucose was added to make the concentration 20g/L (to investigate the influence of common components in tetracycline antibiotics production wastewater on the treatment effect of powdered activated carbon).

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM, and glucose 20g/L. Add powdered activated carbon according to 1/400 of the water quality, and stir intermittently for 5-10 minutes every 8 hours. After 36 hours, the concentration of tetracycline in the water after filtering through the screen The removal rate of <0.1μM is nearly 100%.

Example 6

Ordinary tap water was mixed with tetracycline to make the concentration 1mM, and oxalic acid was added to make the concentration 8g/L (to investigate the influence of common components in tetracycline antibiotics production wastewater on the treatment effect of powdered activated carbon).

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM, and oxalic acid 8g/L. Add powdered activated carbon according to 1/400 of the water quality, and stir intermittently for 5-10 minutes every 8 hours. After 36 hours, the concentration of tetracycline in the water after filtering through the screen The removal rate of <0.1μM is nearly 100%.

Example 7

Ordinary tap water is mixed with tetracycline to make the concentration reach 1mM, and glucose, oxalic acid, urea, sodium dihydrogen phosphate and sodium bicarbonate are added respectively to make the concentration reach 7500mg/L, 2000mg/L, 63mg/L, 26mg/L, 50mg/LNaHCO ₃ (to investigate the effect of simulated tetracycline antibiotics production wastewater on the treatment effect of powdered activated carbon).

Processing method is with embodiment 1.

Ordinary tap water contains tetracycline up to 1mM and the above components, add powdered activated carbon according to 1/400 of the water mass, stir intermittently for 5-10 minutes every 8 hours, and after 36 hours, the concentration of tetracycline in the water after filtering through the screen is <0.1μM The removal rate is nearly 100%.

In the above examples, the powdered activated carbon is a powder with a particle size between 100-200 mesh.

Claims (9)

1, utilize Powdered Activated Carbon to handle the method for water body containing tetracycline antibiotics, it is characterized in that adopting following steps:

A, Powdered Activated Carbon and the water that contains tetracycline antibiotics are added container, and adopt intermittently stirring method to handle appropriate time;

B, Powdered Activated Carbon is removed from water body.

2, method according to claim 1 is characterized in that gac is that particle diameter is between 100-200 purpose powder.

3, method according to claim 1 is characterized in that intermittently stirring for per 6～9 hours and stirs once, and stir the time length is 5～10 minutes at every turn.

4, method according to claim 1 is characterized in that adopting the time of stir process at intermittence is 24～48 hours.

5, method according to claim 1 is characterized in that the concentration of tetracycline antibiotics is not more than under the condition of 1mM in water body, and the usage quantity of Powdered Activated Carbon and the mass ratio of water body containing tetracycline antibiotics are 1:400～1000.

6, method according to claim 5 is characterized in that tetracycline antibiotics concentration is not more than under the condition of 1mM in water body, and the usage quantity of Powdered Activated Carbon and the mass ratio of water body containing tetracycline antibiotics are 1: 400～800.

7, method according to claim 6 is characterized in that tetracycline antibiotics concentration is not more than under the condition of 1mM in water body, and the usage quantity of Powdered Activated Carbon and the mass ratio of water body containing tetracycline antibiotics are 0.25%.

8, method according to claim 1 is characterized in that the method for among the step b Powdered Activated Carbon being removed from water body is to adopt 400 eye mesh screens that the water after handling is separated with Powdered Activated Carbon.

9, method according to claim 1 is characterized in that this method reacts at ambient temperature.