阅读说明：本技术 一种反渗透膜环保再生利用方法 (Reverse osmosis membrane environment-friendly recycling method ) 是由 王冬生 潘兴灿 蒋敏 于 2019-11-04 设计创作，主要内容包括：本发明涉及一种反渗透膜环保再生利用方法,包括如下步骤：(1)清洗：将废弃反渗透膜置于超声中进行超声清洗；(2)淋洗：利用高锰酸钾膜清洗剂对超声清洗后的反渗透膜进行淋洗,实现反渗透膜的环保再生利用；所述高锰酸钾膜清洗剂剂由高锰酸钾水溶液、络合剂水溶液和催化剂组成。本发明在现有技术的基础上通过大量实验优化清洗剂中各组分的组成以及清洗过程的反应参数,能够大幅提高反渗透膜的环保再生利用效果,进而降低企业的生产成本,实现资源的回收利用。(The invention relates to an environment-friendly reverse osmosis membrane recycling method, which comprises the following steps: (1) cleaning: placing the waste reverse osmosis membrane in ultrasound for ultrasonic cleaning; (2) leaching: leaching the reverse osmosis membrane subjected to ultrasonic cleaning by using a potassium permanganate membrane cleaning agent, so as to realize environment-friendly recycling of the reverse osmosis membrane; the potassium permanganate film cleaning agent consists of a potassium permanganate aqueous solution, a complexing agent aqueous solution and a catalyst. According to the invention, on the basis of the prior art, the composition of each component in the cleaning agent and the reaction parameters in the cleaning process are optimized through a large number of experiments, so that the environment-friendly recycling effect of the reverse osmosis membrane can be greatly improved, the production cost of an enterprise is further reduced, and the resource recycling is realized.)

1. An environment-friendly reverse osmosis membrane recycling method is characterized by comprising the following steps:

(1) cleaning: placing the waste reverse osmosis membrane in ultrasound for ultrasonic cleaning;

(2) leaching: leaching the reverse osmosis membrane subjected to ultrasonic cleaning by using a potassium permanganate membrane cleaning agent, so as to realize environment-friendly recycling of the reverse osmosis membrane; the potassium permanganate film cleaning agent consists of a potassium permanganate aqueous solution, a complexing agent aqueous solution and a catalyst; wherein the catalyst is sodium sulfite, and the mass ratio of potassium permanganate to complexing agent is 1: 20, the mass ratio of potassium permanganate to the catalyst is 1:1, the pH value of the potassium permanganate membrane cleaning agent is in the range of 5-9.

2. The reverse osmosis membrane environment-friendly recycling method according to claim 1, wherein the complexing agent is prepared from gallic acid and serine in a mass ratio of (2: 1.

3. The reverse osmosis membrane environment-friendly recycling method according to claim 2, wherein the leaching temperature in the step (2) is 60 ℃.

4. The reverse osmosis membrane environment-friendly recycling method according to claim 1, wherein the ultrasonic frequency is 100Hz, and the ultrasonic time is 1 h.

5. The reverse osmosis membrane environment-friendly recycling method according to claim 1, wherein the concentration of the potassium permanganate aqueous solution is 10 mg/L.

6. The reverse osmosis membrane environment-friendly recycling method according to claim 1, wherein the leaching time in the step (2) is 50 min.

Technical Field

The invention relates to an environment-friendly reverse osmosis membrane recycling method.

Background

At present, the membrane separation technology is increasingly applied in the process of treating drinking water, mainly comprises Microfiltration (MF), Ultrafiltration (UF), Nanofiltration (NF), Reverse Osmosis (RO) and the like, and is a novel separation technology. With the development of a membrane preparation process method, a membrane material and the application of the membrane, compared with the conventional traditional technology, the membrane separation technology has the advantages of good water quality of membrane outlet water, high separation precision and less secondary pollution generated in the operation process, and only pressure is required to be used as a driving force.

The microfiltration membrane separation technology is very similar to the traditional rough filtration, the pore size range of the microfiltration membrane is 0.05-10 mu m, the mechanism is that static pressure difference is used as driving force, substances with the particle size smaller than that of the membrane pass through the membrane, and substances with the particle size larger than that of the membrane are intercepted on the other side, so that the separation of components is realized. The aperture range of the ultrafiltration membrane separation technology is 1 nm-0.05 mu m. Similar to microfiltration, the technology also uses pressure as a driving force, and the common application of ultrafiltration is to separate colloid and macromolecular substances in a water body. The nano-filtration membrane is a novel separation membrane developed in the 80 th century, the microporous structure of the surface of the membrane is in the nanometer level, and the nano-filtration membrane mainly removes a solute of about nanometer. The two processes of the reverse osmosis technique and the nanofiltration technique can be regarded as one process, and the mechanisms of the two processes are the same.

In many cases, natural water supplies are decreasing due to climate change and excessive mining, and solutions such as water conservation and shipping or building new dams are not sufficient to cope with the ever increasing demand. Therefore, the most urgent challenges today include the recovery of clean drinking water from salt water or seawater, and the treatment and recovery of wastewater.

Reverse Osmosis (RO) is currently the most important and common desalination technology, and its application is now becoming more widespread. Over the past several decades, significant advances have been made in the materials and techniques used to prepare reverse osmosis membranes. In addition to the continuous research on traditional polymer reverse osmosis membrane materials, nanotechnology opens the way for incorporating nanomaterials into reverse osmosis processes. Commercialization of reverse osmosis technology is increasing worldwide, which in turn contributes to a substantial reduction in cost. The progress of reverse osmosis technology at this stage mainly includes development of membrane material and module design, process design, pretreatment and energy consumption reduction in the operation process. Since 1978, the increase in mechanical, biological and chemical strength and permeability of reverse osmosis membranes has reduced the cost of water per unit volume by more than 10-fold.

Reverse Osmosis (RO) membrane technology is one of the most important technologies for contemporary water treatment. Among them, membrane fouling is one of the most major factors limiting its development. Membrane fouling can cause a number of operational problems, such as: the flow rate decreases, which requires higher operating pressures and therefore increases the energy consumption; increasing the times of chemical and physical cleaning; the membrane service time is also shortened; increase the operating cost of reverse osmosis technology, etc. In general, membrane fouling is the accumulation of contaminants on the membrane surface or within the membrane pores, resulting in a decrease in permeate flux and salt rejection.

Depending on the location of the contamination, there are two types of contamination, surface contamination and internal contamination. The fouling mechanism of low pressure membranes (i.e., MF and UF) is different from those of high pressure membranes. Adsorption and plugging within the pore size is more common for MF and UF, while surface fouling is more common for NF and RO due to their relatively compact and non-porous structural characteristics. Surface contamination is more easily controlled by improving influent hydraulic conditions or chemical cleaning than internal contamination. Thus, it is generally more reversible than internal contamination. However, in practice, reversible and irreversible fouling should depend on the influent water components as they interact with the membrane, and both internal and membrane surface fouling may become irreversible.

Chinese patent CN108380057A discloses a method for cleaning and regenerating irreversible pollutants of a waste reverse osmosis membrane based on printing and dyeing wastewater treatment, however, the regeneration effect of the method is not ideal, and the method still has room for improvement. Therefore, in order to realize the environmental recycling of the reverse osmosis membrane, further improvement on the prior art is urgently needed.

Disclosure of Invention

In order to solve the technical problem that the regeneration effect of a reverse osmosis membrane in the prior art is not ideal, the invention provides the following technical scheme:

an environment-friendly reverse osmosis membrane recycling method comprises the following steps:

(1) cleaning: placing the waste reverse osmosis membrane in ultrasound for ultrasonic cleaning;

(2) leaching: leaching the reverse osmosis membrane subjected to ultrasonic cleaning by using a potassium permanganate membrane cleaning agent, so as to realize environment-friendly recycling of the reverse osmosis membrane; the potassium permanganate film cleaning agent consists of a potassium permanganate aqueous solution, a complexing agent aqueous solution and a catalyst; wherein the catalyst is sodium sulfite, and the mass ratio of potassium permanganate to the complexing agent is 1: 20, the mass ratio of potassium permanganate to the catalyst is 1:1, the pH value of the potassium permanganate membrane cleaning agent is in the range of 5-9.

Preferably, the complexing agent is prepared from gallic acid and serine in a mass ratio of 2: 1.

Preferably, the leaching temperature in step (2) is 60 ℃.

Preferably, the frequency of the ultrasound is 100Hz, and the ultrasound time is 1 h.

Preferably, the concentration of the potassium permanganate aqueous solution is 10 mg/L.

Preferably, the rinsing time in step (2) is 50 min.

The technical scheme of the invention has the following beneficial effects:

(1) according to the invention, on the basis of the prior art, the composition and relevant reaction parameters of each component are optimized through a large number of experiments, so that the environment-friendly recycling effect of the reverse osmosis membrane can be greatly improved, the production cost of enterprises is further reduced, and the recycling of resources is realized.

(2) According to the invention, the gallic acid and the serine are used as complexing agents, so that the self decomposition speed of high-activity intermediate state manganese can be synergistically reduced, and the capability of potassium permanganate in oxidizing refractory organic matters is enhanced. It can be seen from comparative examples 1-3 that not any two organic acids produce the best synergistic effect, for example, if neither gallic acid nor serine is replaced by citric acid, nor glycine, the desired rinsing effect is achieved, which is not the desired technical effect. Further, the mass ratio of gallic acid to serine was found to be 2: the effect produced at 1 is best, better than 3:1 and 1:1, and the technical effect is unpredictable.

(3) As can be seen from examples 1-4, the optimum rinsing temperature is not the 50 ℃ claimed in the prior art, and through a number of experiments it was found that the optimum rinsing temperature should be 60 ℃ and that the higher the temperature is not the better, and that the rinsing effect starts to decrease after the rinsing temperature exceeds 60 ℃ during the course of the study, which technical effect was not predictable.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the following examples and comparative examples.