阅读说明：本技术 一种针对pam与无机物复合污染超滤膜的清洗方法 (Cleaning method for PAM and inorganic matter composite pollution ultrafiltration membrane ) 是由 陈泉学 于 2021-07-01 设计创作，主要内容包括：本发明提出了一种针对PAM与无机物复合污染超滤膜的清洗方法,包括,首先排空超滤膜系统内的明水,然后将氧化药剂加热至35-45℃后充满超滤膜系统,保温浸泡处理12-24h,浸泡完毕,排出氧化药剂；然后继续排空超滤膜系统内的明水,然后将清洗药剂加热至35-45℃后充满超滤膜系统,保温浸泡处理12-24h,浸泡完毕,排出清洗药剂；最后关闭膜系统产水口,通过进水口进水,浓水口排水,进行超滤膜系统清洗,清洗用水为反渗透产水,清洗用水的温度为35-45℃,清洗用水的水压为0.1MPa,清洗时间为1-4h。采用本方法清洗处理后的超滤膜组件具有良好的水通量恢复率。(The invention provides a cleaning method for a PAM and inorganic matter composite pollution ultrafiltration membrane, which comprises the steps of firstly emptying the open water in an ultrafiltration membrane system, then heating an oxidizing agent to 35-45 ℃, filling the ultrafiltration membrane system with the oxidizing agent, carrying out heat preservation soaking treatment for 12-24h, and discharging the oxidizing agent after soaking; then, continuously evacuating open water in the ultrafiltration membrane system, heating the cleaning agent to 35-45 ℃, filling the ultrafiltration membrane system with the cleaning agent, carrying out heat preservation soaking treatment for 12-24h, and discharging the cleaning agent after soaking; and finally closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water producing water, the temperature of the cleaning water is 35-45 ℃, the water pressure of the cleaning water is 0.1MPa, and the cleaning time is 1-4 h. The ultrafiltration membrane component cleaned and treated by the method has good water flux recovery rate.)

1. A cleaning method for an ultrafiltration membrane compositely polluted by PAM and inorganic matters is characterized by comprising the following steps:

step one, emptying open water in an ultrafiltration membrane system, heating an oxidizing agent to 35-45 ℃, filling the ultrafiltration membrane system with the oxidizing agent, carrying out heat preservation soaking treatment for 12-24h, and discharging the oxidizing agent after soaking;

step two, emptying open water in the ultrafiltration membrane system, heating the cleaning agent to 35-45 ℃, filling the ultrafiltration membrane system with the cleaning agent, carrying out heat preservation soaking treatment for 12-24h, and discharging the cleaning agent after soaking;

and step three, closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the temperature of the cleaning water is 35-45 ℃, the water pressure of the cleaning water is 0.1MPa, and the cleaning time is 1-4 hours.

2. The method for cleaning the ultrafiltration membrane compositely polluted by the PAM and the inorganic matters according to claim 1, wherein in the first step, after the oxidizing agent is discharged, air is introduced into the ultrafiltration membrane system from a water inlet to perform air scrubbing, the air pressure is 0.1MPa, and the air scrubbing time is 30-60 min.

3. The cleaning method for the PAM and inorganic matter combined pollution ultrafiltration membrane as claimed in claim 2, further comprising introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing after air scrubbing is finished, wherein the water inlet pressure is 0.2MPa, the backwashing time is 10-20min, and the ultrafiltration production water is introduced into the ultrafiltration membrane system through a water inlet port for forward washing after backwashing is finished, wherein the water inlet pressure is 0.1MPa, and the forward washing time is 5-10 min.

4. The method for cleaning the ultrafiltration membrane compositely polluted by the PAM and the inorganic matters according to claim 1, wherein in the second step, after the cleaning agent is discharged, air is introduced into the ultrafiltration membrane system from the water inlet to perform air scrubbing, the air pressure is 0.1MPa, and the air scrubbing time is 30-60 min.

5. The method for cleaning the PAM and inorganic matter combined pollution ultrafiltration membrane as claimed in claim 4, further comprising introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing after air scrubbing is finished, wherein the water inlet pressure is 0.2MPa, the backwashing time is 10-20min, and the ultrafiltration production water is introduced into the ultrafiltration membrane system through a water inlet port for forward washing after backwashing is finished, wherein the water inlet pressure is 0.1MPa, and the forward washing time is 5-10 min.

6. The method for cleaning the ultrafiltration membrane compositely polluted by the PAM and the inorganic matters according to claim 1, wherein in the third step, the using amount of the cleaning water is not less than 10 times of the volume of the cavity of the ultrafiltration membrane system.

7. The method for cleaning the PAM and inorganic substance combined pollution ultrafiltration membrane as claimed in claim 1, wherein in the first step, the oxidizing agent comprises, by mass, 0.5-1% of sodium hydroxide, 0.1-0.5% of sodium hypochlorite and the balance of water, wherein the oxidizing agent accounts for 100%.

8. The method for cleaning the ultrafiltration membrane compositely contaminated by PAM and inorganic substances according to claim 1, wherein in the second step, the cleaning agent comprises, by mass, 0.5-1% of disodium edetate and the balance of water, calculated as 100%.

9. The method for cleaning the PAM and inorganic substance combined pollution ultrafiltration membrane according to any one of claims 7 and 8, wherein the water is reverse osmosis produced water.

Technical Field

The invention relates to the technical field of ultrafiltration membrane cleaning, in particular to a cleaning method for an ultrafiltration membrane compositely polluted by PAM and inorganic matters.

Background

Due to good separation performance, the ultrafiltration membrane is widely applied to standard-reaching discharge or recycling of polluted wastewater, in a sewage treatment process with high metal ion content, metal ions are precipitated by means of alkali addition and the like, at the moment, if the metal ions directly enter a membrane system, the membrane module is blocked due to high content of suspended matters, in order to reduce the content of the suspended matters in raw water, the general method is that a PAM flocculating agent is added to enable sludge to be settled to the bottom of a pool, and then supernatant is pumped to the membrane system for treatment.

Although the method can avoid a large amount of PAM suspended substances from entering the membrane system, PAM is not easy to dissolve and not cured completely, so that the addition amount is not easy to control, excessive addition is not easy and the like. Some PAM can be mixed in inorganic matter and get into membrane system, because PAM viscosity is very high itself, general physical chemistry is washd and is difficult thoroughly to elute, through dissecting the milipore filter subassembly that receives this type of pollution, can find, is full of thick compound pollutant between the membrane silk, and conventional physical chemistry cleaning method hardly has any effect of wasing to this type of pollutant, consequently, need put forward a more suitable cleaning method to PAM-inorganic matter to guarantee membrane system's washing validity.

Disclosure of Invention

In view of the above, the invention provides a cleaning method for an ultrafiltration membrane compositely polluted by PAM and inorganic matters.

The technical scheme of the invention is realized as follows: the invention provides a cleaning method for a PAM and inorganic matter composite pollution ultrafiltration membrane, which comprises the following steps:

firstly, emptying open water in an ultrafiltration membrane system, then heating an oxidizing agent to 25-45 ℃, filling the oxidizing agent into the ultrafiltration membrane system, carrying out heat preservation soaking treatment for 12-24 hours, and discharging the oxidizing agent after soaking;

continuously evacuating the open water and the oxidizing agent in the ultrafiltration membrane system, heating the cleaning agent to 35-45 ℃, filling the ultrafiltration membrane system with the cleaning agent, carrying out heat preservation soaking treatment for 12-24h, and discharging the cleaning agent after soaking;

and step three, closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the temperature of the cleaning water is 35-45 ℃, the water pressure of the cleaning water is 0.1MPa, and the cleaning time is 1-4 hours.

On the basis of the above technical scheme, preferably, in the step one, after the oxidizing agent is discharged, air is introduced into the ultrafiltration membrane system from the water inlet to perform air scrubbing, the air pressure is 0.1MPa, and the air scrubbing time is 30-60 min.

On the basis of the technical scheme, preferably, after the air scrubbing is finished, the method further comprises the steps of introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing, wherein the water inlet pressure is 0.2MPa, the backwashing time is 10-20min, and after the backwashing is finished, introducing the ultrafiltration production water into the ultrafiltration membrane system through a water inlet for forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 5-10 min.

On the basis of the above technical scheme, preferably, in the second step, after the cleaning agent is discharged, air is introduced into the ultrafiltration membrane system from the water inlet to perform air scrubbing, the air pressure is 0.1MPa, and the air scrubbing time is 30-60 min.

Preferably, after the air scrubbing is finished, the method further comprises the steps of introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing, wherein the water inlet pressure is 0.2MPa, the backwashing time is 10-20min, and after the backwashing is finished, introducing the ultrafiltration production water into the ultrafiltration membrane system through a water inlet for forward flushing, wherein the water inlet pressure is 0.1MPa, and the forward flushing time is 5-10 min.

On the basis of the technical scheme, preferably, in the third step, the using amount of the cleaning water is not less than 10 times of the volume of the cavity of the ultrafiltration membrane system.

On the basis of the above technical solution, preferably, in the step one, the oxidizing agent includes, by mass, 0.5 to 1% of sodium hydroxide, 0.1 to 0.5% of sodium hypochlorite, and the balance of water, calculated as 100%.

On the basis of the above technical scheme, preferably, in the second step, the cleaning agent comprises, by mass, 0.5 to 1% of disodium edetate and the balance of water, calculated as 100%.

Compared with the prior art, the cleaning method for the ultrafiltration membrane compositely polluted by the PAM and the inorganic matters has the following beneficial effects:

(1) the invention provides a cleaning method for PAM and inorganic matter composite pollution ultrafiltration membrane, which adopts an oxidizing agent for soaking and cleaning, can carry out oxidative decomposition on polyacrylamide, thereby leading the polyacrylamide to be easier to fall off from a membrane component, promoting the falling off of pollutants by an air scrubbing mode, and compared with pure soaking and washing, the cleaning method has higher cleaning efficiency and better effect;

(2) in order to enable the cleaning to be more complete, the technical scheme of the invention also adds the washing agent to carry out the soaking cleaning of the washing agent on the membrane component after the soaking treatment of the oxidation agent is finished, so that the dirt after the oxidation decomposition can be promoted to be quickly fallen off from the surface of the membrane component, and meanwhile, the air scrubbing and the positive and negative washing operations are also adopted after the soaking cleaning of the washing agent, so that the surface cleanliness of the ultrafiltration membrane is higher, the recovery effect of water treatment is good, and the ultrafiltration membrane has a good application prospect.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Example 1

Respectively weighing 0.5kg of sodium hydroxide, 0.1kg of sodium hypochlorite and 99.4kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 35 ℃, and preserving heat for later use.

0.5kg of disodium ethylene diamine tetraacetate and 99.5kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 35 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 12 hours, and discharging the oxidation medicament after soaking;

continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 12 hours, and then discharging the cleaning agent;

closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 35 ℃, and the ultrafiltration membrane system is washed for 1 hour to obtain the cleaned ultrafiltration membrane system.

Example 2

Respectively weighing 0.6kg of sodium hydroxide, 0.2kg of sodium hypochlorite and 99.2kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 40 ℃, and preserving heat for later use.

0.6kg of disodium ethylene diamine tetraacetate and 99.4kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 40 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 16h, and discharging the oxidation medicament after soaking;

after the oxidizing agent is discharged, introducing air into the ultrafiltration membrane system from the water inlet to carry out air scrubbing for 30min, wherein the air pressure is 0.1 MPa;

after the air scrubbing is finished, continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 16 hours, and then discharging the cleaning agent;

closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 40 ℃, and the ultrafiltration membrane system is washed for 2 hours to obtain the cleaned ultrafiltration membrane system.

Example 3

Respectively weighing 0.7kg of sodium hydroxide, 0.3kg of sodium hypochlorite and 99kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 45 ℃, and preserving heat for later use.

0.7kg of disodium ethylene diamine tetraacetate and 99.3kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 45 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 20 hours, and discharging the oxidation medicament after soaking;

after the oxidizing agent is discharged, introducing air into the ultrafiltration membrane system from the water inlet to carry out air scrubbing, wherein the air pressure is 0.1MPa, and the air scrubbing treatment is carried out for 60 min;

after air scrubbing is finished, ultrafiltration product water is introduced into the ultrafiltration membrane system through the water producing port to carry out backwashing, the water inlet pressure is 0.2MPa, the backwashing time is 10min, after backwashing is finished, the ultrafiltration product water can be introduced into the ultrafiltration membrane system through the water inlet port to carry out forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 5 min.

Continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 20 hours, and then discharging the cleaning agent;

and closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 45 ℃, and the ultrafiltration membrane system is washed for 3 hours to obtain the cleaned ultrafiltration membrane system.

Example 4

Respectively weighing 0.8kg of sodium hydroxide, 0.4kg of sodium hypochlorite and 98.8kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 40 ℃, and preserving heat for later use.

0.8kg of disodium ethylene diamine tetraacetate and 99.2kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 40 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and discharging the oxidation medicament after soaking;

after the oxidizing agent is discharged, introducing air into the ultrafiltration membrane system from the water inlet to carry out air scrubbing for 30min, wherein the air pressure is 0.1 MPa;

after air scrubbing is finished, ultrafiltration product water is introduced into the ultrafiltration membrane system through the water producing port to carry out backwashing, the water inlet pressure is 0.2MPa, the backwashing time is 10min, after backwashing is finished, the ultrafiltration product water can be introduced into the ultrafiltration membrane system through the water inlet port to carry out forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 5 min.

Continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and then discharging the cleaning agent;

and introducing air into the ultrafiltration membrane system from the water inlet for air scrubbing, wherein the air pressure of the introduced air is 0.1MPa, and the air scrubbing time is 30 min.

And (3) after air scrubbing is finished, closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis produced water, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 40 ℃, and the ultrafiltration membrane system is washed for 3 hours to obtain the cleaned ultrafiltration membrane system.

Example 5

Respectively weighing 0.8kg of sodium hydroxide, 0.4kg of sodium hypochlorite and 98.8kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 40 ℃, and preserving heat for later use.

0.8kg of disodium ethylene diamine tetraacetate and 99.2kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 40 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and discharging the oxidation medicament after soaking;

after the oxidizing agent is discharged, introducing air into the ultrafiltration membrane system from the water inlet to carry out air scrubbing for 30min, wherein the air pressure is 0.1 MPa;

after air scrubbing is finished, ultrafiltration product water is introduced into the ultrafiltration membrane system through the water producing port to carry out backwashing, the water inlet pressure is 0.2MPa, the backwashing time is 20min, after backwashing is finished, the ultrafiltration product water can be introduced into the ultrafiltration membrane system through the water inlet port to carry out forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 10 min.

Continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and then discharging the cleaning agent;

and introducing air into the ultrafiltration membrane system from the water inlet for air scrubbing, wherein the air pressure of the introduced air is 0.1MPa, and the air scrubbing time is 60 min.

After air scrubbing is finished, introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing, wherein the water inlet pressure is 0.2MPa, the backwashing time is 10min, after backwashing is finished, introducing ultrafiltration production water into the ultrafiltration membrane system through a water inlet for forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 5 min;

closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 40 ℃, and the ultrafiltration membrane system is washed for 3 hours to obtain the cleaned ultrafiltration membrane system.

Example 6

Respectively weighing 0.8kg of sodium hydroxide, 0.4kg of sodium hypochlorite and 98.8kg of water, mixing and stirring uniformly to obtain an oxidation medicament, heating to 40 ℃, and preserving heat for later use.

0.8kg of disodium ethylene diamine tetraacetate and 99.2kg of water are respectively weighed, mixed and stirred uniformly to obtain a cleaning agent, heated to 40 ℃, and kept warm for later use.

Draining the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with an oxidation medicament for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and discharging the oxidation medicament after soaking;

after the oxidizing agent is discharged, introducing air into the ultrafiltration membrane system from the water inlet to carry out air scrubbing for 30min, wherein the air pressure is 0.1 MPa;

after air scrubbing is finished, ultrafiltration product water is introduced into the ultrafiltration membrane system through the water producing port to carry out backwashing, the water inlet pressure is 0.2MPa, the backwashing time is 20min, after backwashing is finished, the ultrafiltration product water can be introduced into the ultrafiltration membrane system through the water inlet port to carry out forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 10 min.

Continuously emptying the open water in the ultrafiltration membrane system, filling the ultrafiltration membrane system with a cleaning agent for standby heat preservation, carrying out heat preservation soaking treatment for 24 hours, and then discharging the cleaning agent;

and introducing air into the ultrafiltration membrane system from the water inlet for air scrubbing, wherein the air pressure of the introduced air is 0.1MPa, and the air scrubbing time is 60 min.

After air scrubbing is finished, introducing ultrafiltration production water into the ultrafiltration membrane system through a water production port for backwashing, wherein the water inlet pressure is 0.2MPa, the backwashing time is 20min, after backwashing is finished, introducing ultrafiltration production water into the ultrafiltration membrane system through a water inlet for forward flushing, the water inlet pressure is 0.1MPa, and the forward flushing time is 10 min;

closing a water producing port of the membrane system, feeding water through a water inlet, discharging water through a concentrated water port, and cleaning the ultrafiltration membrane system, wherein the cleaning water is reverse osmosis water production, the cleaning water consumption is not less than 10 times of the volume of a cavity of the ultrafiltration membrane system, the water feeding pressure is controlled to be 0.1MPa, the water feeding temperature is controlled to be 40 ℃, and the ultrafiltration membrane system is washed for 3 hours to obtain the cleaned ultrafiltration membrane system.

Comparative example

And cleaning the ultrafiltration membrane system to be cleaned by adopting a conventional aeration cleaning and backwashing mode, wherein the cleaning time is 30min, the cleaning pressure is 0.2MPa, the backwashing time is 10min, and the backwashing water inlet pressure is 0.1 MPa.

Respectively carrying out water treatment detection on the treated ultrafiltration membrane systems, and calculating a recovery value of the water yield to obtain the following results:

grouping

Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Comparative example

Recovery of water productionRate of change

81％

83％

85％

88％

89％

93％

63％

From the data, the cleaning method can effectively improve the cleaning efficiency of the ultrafiltration membrane, has good cleaning effect on the blockage of the ultrafiltration membrane caused by pollutants such as polyacrylamide, inorganic matters and the like, and can ensure that the service life of the membrane system cleaned by the above embodiment can reach at least 3 years through tests.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.