CN114349121A - Method for removing haloacetic acid substances in swimming pool water - Google Patents
Method for removing haloacetic acid substances in swimming pool water Download PDFInfo
- Publication number
- CN114349121A CN114349121A CN202210082522.5A CN202210082522A CN114349121A CN 114349121 A CN114349121 A CN 114349121A CN 202210082522 A CN202210082522 A CN 202210082522A CN 114349121 A CN114349121 A CN 114349121A
- Authority
- CN
- China
- Prior art keywords
- water
- membrane
- swimming pool
- cleaning
- flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention provides a method for removing haloacetic acid substances in swimming pool water. The method comprises the following steps: cutting a membrane material, soaking the membrane material in a glass bottle containing deionized water for 24 hours, taking out and cleaning the membrane material for later use; starting a nanofiltration/reverse osmosis system, cleaning the membrane system by using deionized water under low pressure, and installing a membrane in a membrane pool after cleaning; adding actual swimming pool water or simulated swimming pool water into a water storage tank, adjusting the temperature, pressure and flow, and sampling to detect the concentration of haloacetic acid substances after the system runs stably; the detection method of the haloacetic acid substances is based on detection of a gas chromatography mass spectrum after liquid-liquid extraction derivatization treatment of a water sample proposed by EPA 552.3. The method utilizes the membrane separation process to remove the haloacetic acid substances in the swimming pool water, and has the advantages of simple process, simple and convenient operation, high removal rate and the like.
Description
Technical Field
The invention relates to the technical field of treatment of disinfection byproducts in water, in particular to a method for removing haloacetic acid substances in swimming pool water.
Background
Swimming is a very popular sport and recreational activity in recent years. Swimming pools are generally disinfected by disinfectants such as chlorine, sodium hypochlorite or calcium hypochlorite, so as to avoid infectious diseases caused by pathogenic microorganisms in water bodies. However, the use of chlorine-containing disinfectants in large quantities, coupled with the long residence time of the pool water, results in the production of high concentrations of haloacetic acids (HAAs) in the pool water. The haloacetic acid species are mainly nine species, including monochloroacetic acid (MCAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), monobromoacetic acid (MBAA), dibromoacetic acid (DBAA), tribromoacetic acid (TBAA), monochloromonobromoacetic acid (BCAA), monobromodichloroacetic acid (BDCAA), and monochlorodibromoacetic acid (CDBAA). Due to the potential genotoxicity and carcinogenicity of HAAs, the united states environmental protection agency (u.s. EPA) has regulated five haloacetic acids (HAA), MCAA, DCAA, TCAA, MBAA and DBAA, in the drinking water regulatory guidelines5) Does not exceed 60 ug/L of total concentration Maximum Contamination Level (MCL). The China Drinking Water Standard (GB 5749-2006) stipulates that the MCL of DCAA does not exceed 50 ug/L, and the MCL of TCAA does not exceed 100 ug/L. However, no pool water quality standards have incorporated HAAs into the conventional regulatory guidelines.
Previous literature investigations have found that HAAs levels in pool water are typically several orders of magnitude higher than MCL for drinking water. The concentration of HAAs in the swimming pool water can reach 3488 ug/L at most. Pool water contains a large amount of precursor substances that generate haloacetic acids, including natural organic matter from source water, swimmer body fluids (urine and perspiration), and personal care products (sunscreens, lotions, shampoos, and other cosmetics) that are released from the human skin or urine. Thus, high concentrations of organic substrates in swimming pool water are more likely to generate disinfection by-products than drinking water (the primary substrate is natural organic matter). A number of animal cancer statistics have demonstrated that HAAs contained in drinking water are carcinogenic and cytotoxic. Among them, DCAA is well-defined as a possible carcinogen in human body (2B), and has genetic toxicity. Therefore, if a swimmer is exposed to swimming pool water with high HAAs concentration for a long time, it may have a great negative impact on the health. In view of the health risks caused by HAAs in swimming pool water, how to effectively remove haloacetic acid in swimming pool water becomes a technical problem to be solved in the field.
Conventional pool water treatment systems (flocculation-sand filtration-chlorination) do not effectively remove HAAs or HAAs precursors. Therefore, aiming at the characteristics of the substrate in the swimming pool water, the HAAs are mainly removed by adopting the processes of advanced oxidation, biodegradation, membrane separation and the like. Advanced oxidation uses hydroxyl radical (. OH) as active ingredient and utilizes UV and H2O2Or O3Can effectively degrade HAAs in water environment. However, humic acid, nitrate, chloride and sulfate which are common in swimming pool water can shield OH, thereby influencing the photodegradation efficiency of HAAs. Furthermore, HAAs are generally degraded to smaller molecular weight organics, the toxicity of which is still unknown. Biodegradation is an effective process for removing HAAs in aqueous systems, but its application is limited by the high concentration of disinfectant residues in the swimming pool water, whose strong oxidizing properties may inactivate the corresponding biodegradable bacteria. In addition, other parameters such as water temperature, residence time, organic composition, etc. can also affect the efficiency of biochemical degradation of HAAs. The membrane separation process is widely applied to removing trace pollutants and has the characteristics of simple principle, convenient operation and high pollutant removal efficiency. Under the pH value (6.0-7.0) of the solution of the swimming pool water, most of the polyamide basement membrane surface is negatively charged, and pK isaHAA values between 0.05 and 2.73 dissociate into anionic form, and the enhancement of charge repulsion favors the retention of HAAs. It is therefore an object of the present invention to demonstrate an efficient and easy to operate method for removing HAAs from swimming pool water by a membrane separation process.
Disclosure of Invention
The invention aims to provide a method for removing haloacetic acid substances in swimming pool water, which effectively controls the concentration of haloacetic acid in the swimming pool water by utilizing a method with convenient operation.
In order to achieve the purpose, the invention adopts the following technical scheme. The invention utilizes reverse osmosis and a nanofiltration membrane to remove haloacetic acid substances in the swimming pool water, and concretely comprises the following steps:
(1) membrane cleaning
Cutting the membrane material, soaking in a glass bottle containing deionized water for 24 h, taking out, and cleaning for later use.
The membrane material is four common commercial flat nanofiltration/reverse osmosis membranes, including two nanofiltration membranes (NF90 and NF270) and two reverse osmosis membranes (XLE and SB50), and the cutting size of the membrane is 5 cm multiplied by 10 cm.
The conductivity of the deionized water is less than 0.4 us/cm.
The glass bottle is a 250 mL brown screw-top reagent bottle.
The cleaning refers to washing with deionized water for 4-5 times to remove impurities detached from the surface of the membrane after soaking.
(2) Nanofiltration/reverse osmosis system cleaning
And starting the nanofiltration/reverse osmosis system, cleaning the membrane system by using deionized water under low pressure, and installing the membrane in the membrane pool after cleaning.
The nanofiltration/reverse osmosis system is a device which is composed of four identical rectangular cross-flow membrane tanks, a water storage tank, a booster pump, a water chiller and the like and can accurately regulate and control temperature, pressure and flow.
Further, the effective area of the inner membrane of the rectangular cross-flow membrane pool is 42 cm2(4.6 cm multiplied by 9.2 cm), and a diaphragm gasket with the thickness of 1.2 mm is additionally arranged in each diaphragm tank.
Further, the water storage tank has a volume of 30L, and is made of stainless steel, and the penetrating fluid and the concentrated solution can completely flow back into the water storage tank to keep a constant inlet water concentration.
Furthermore, the temperature is regulated by utilizing a temperature control knob, the constant temperature of the system is maintained by the running of the water chiller, and the temperature of the system is displayed by a thermometer.
Furthermore, the pressure regulation and control means that the pressure is regulated by using a pressure knob, the high-pressure pump operates to maintain the constant pressure of the system, and the pressure of the system is displayed by a pressure gauge connected to each pipeline.
Further, the flow regulation and control means that a flow valve connected to each pipeline is used for regulating the flow, and the system flow is displayed by a flow meter connected to each pipeline.
The low pressure is 0.2 bar.
The cleaning is to remove the impurities remained in the system, the cleaning time is 10 min each time, and the cleaning is carried out for 2-3 times.
(3) Nanofiltration/reverse osmosis system operation
Adding the actual swimming pool water or the simulated swimming pool water into a water storage tank, adjusting the temperature, the pressure and the flow, and sampling after the system runs stably
The swimming pool water is taken from an indoor swimming pool which normally operates in a district of a certain city, the effective volume is 20L, and the water sample is taken and used.
The configuration simulation swimming pool water is configured based on the concentration and salinity of HAAs contained in the actual swimming pool water, only HAAs and sodium chloride are added, other components are not added to eliminate the interference of other matrixes, and the effective volume is 20L.
The stable system means that the temperature, the pressure and the flow of the system do not change along with the time after the system runs for at least 8 hours, the system is in a stable state, and the membrane flux is kept constant.
The sampling port is a penetrating fluid outlet port, and a water sample is stored in a sampling bottle in a sealed manner.
Further, the sampling bottle is a 40 mL brown glass bottle with a screw-top plug and a polytetrafluoroethylene liner, and is washed with deionized water and dried several times before sampling.
Further, the sealed preservation is to store the water sample in a brown bottle, and the preservation time is less than 7 days below 4 ℃.
(4) Sample detection
The detection method of HAAs is based on detection by Gas Chromatography Mass Spectrometry (GCMS) after liquid-liquid extraction derivatization treatment of a water sample proposed by EPA 552.3.
The liquid-liquid extraction refers to extraction of HAAs in water by using methyl tert-butyl ether.
The derivatization refers to the generation of HAAs derivative products by utilizing acidic methanol
Further, the volume ratio of the acidic methanol to the methanol sulfuric acid is 1: 10, in water.
The GCMS detects that the analyzed target object is methylated HAAs.
The invention has the beneficial effects that:
the invention provides a method for efficiently removing HAAs in a swimming pool water body by utilizing a membrane separation process.
The method has the advantages of simple process, simple and convenient operation, short treatment time and high haloacetic acid removal rate.
The commercial nanofiltration and reverse osmosis membrane used by the method has low price and high economic benefit.
The method of the invention does not need to add chemical reagents and has no extra medicament loss.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic view of the apparatus for removing HAAs from swimming pool water according to the present invention.
Detailed Description
In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.
In specific implementation, the nanofiltration/reverse osmosis device used by the invention is shown in figure 1, and comprises a water storage tank, wherein the lower end of the water storage tank is connected with a feed liquid outlet pipe, the upper end of the water storage tank is connected with a penetrating fluid inlet pipe, the water storage tank is made of stainless steel, and the side wall of the water storage tank is hollow and is used for replacing temperature control water of a water chiller. The water outlet pipeline of the water storage tank is connected with a control valve control pipeline switch and a booster pump for regulating and controlling the system pressure. The feed liquid is further divided into four branch pipelines, and each pipeline is connected with a flow regulating valve, a flow meter and a pressure gauge to regulate and control the flow and display the flow and the pressure of the pipelines. The penetrating fluid filtered by the membrane tank in the branch pipeline and the concentrated solution generated by filtering both flow back to the water storage tank.
In practice, the membrane materials used are commercial flat nanofiltration/reverse osmosis polyamide membranes, specifically two nanofiltration membranes (NF90 and NF270) and two reverse osmosis membranes (XLE and SB 50).
Example 1
(1) Cutting four commercial flat nanofiltration/reverse osmosis polyamide membranes, soaking the cut membranes in a glass bottle containing deionized water for 24 hours, taking out the membranes, and washing the membranes for 4 to 5 times by using the deionized water for later use;
(2) starting a nanofiltration/reverse osmosis system, and cleaning nanofiltration/reverse osmosis for 2 times by using deionized water under the pressure of 0.2 bar;
(3) after cleaning, the membrane is installed in the membrane pool, deionized water is added into the water storage tank, the booster pump is started, the filtration time is kept for at least 8 hours, the system is in a stable state, the temperature, the pressure and the flow rate are not changed along with the time, and the membrane flux is kept constant.
(4) After the system was stabilized, the pool simulated water was made up of sodium chloride and HAAs in a tank containing 0.05 mol/L NaCl and 900. mu.g/L HAAs (100. mu.g/L for each HAA), with salinity and HAAs concentrations based on the actual pool water salinity and HAAs content, and was carried out at a constant cross-flow rate of 0.8L/min at 25 ℃, pH 7.5, and 100 psi.
(5) And sampling according to time points, respectively detecting the concentration of HAAs in the feed liquid and the penetrating fluid, and calculating the removal efficiency of the HAAs in water by using the method. The pretreatment process and the analysis method of HAAs in the water sample are as follows:
1) pretreating a water sample, extracting HAAs from an inorganic phase into methyl tert-butyl ether, derivatizing the HAAs with acidic methanol, extracting a derivatization product, and storing the derivatization product in a 2 mL GC-MS sample injection bottle;
2) the detection was carried out by using Shimadzu GCMS-TQ8050 gas chromatograph, and the type of the column was DB-5MS (film thickness 0.25 um, length 30 m, inner diameter 0.25 mm). The chromatographic analysis conditions were:
a) GC procedure: the carrier gas used in the GC procedure was helium, which had an average linear velocity of 51 cm/sec and a constant pressure of 112 kPa during the run of the procedure. The temperature of the sample inlet is 230 ℃, the sample injection mode of non-split flow sample injection is adopted, and the solvent injection amount is 1 mu L. The total flow rate for the GC procedure was 28 mL/min, the column flow rate was 2 mL/min, the purge flow rate was 6 mL/min, and the split ratio was 10. The initial temperature of the column was 40 deg.C, held for 6.5 min, then ramped at 10 deg.C/min to 150 deg.C, held for 0 min, and ramped at 30 deg.C/min to 250 deg.C.
b) MS program: the interface temperature of the MS program was 280 ℃, the ion source temperature was 230 ℃, the solvent delay time was 3 min, and the total time was 16 min.
Table 1 shows the removal rates of 9 different types of HAAs by four commercial flat membranes in a simulated pool water matrix background.
The results show that under the background of simulated swimming pool water matrix, the removal efficiency of three membrane materials of XLE, NF90 and SB50 on 9 HAAs is high, and the removal rate can reach more than 92%. The removal rate of NF270 to HAAs is good, and the removal rate exceeds 63 percent.
Example 2
(1) The cutting and cleaning of the membrane material are the same as in example 1;
(2) the nanofiltration/reverse osmosis system is started and cleaned as in example 1;
(3) the nanofiltration/reverse osmosis system was stabilized as in example 1;
(4) after the system is stabilized, adding the actual swimming pool water into the water storage tank, taking the swimming pool water from a certain swimming pool which normally runs,
this example was carried out at a constant cross flow rate of 0.8L/min at a temperature of 25 deg.C, pH 7.5, and pressure of 100 psi;
(5) sampling and HAAs testing were the same as in example 1.
Table 2 shows the removal rates of 9 different types of HAAs by four commercial flat membranes against a real pool water matrix background.
The concentration of CAA, BAA, DBCAA and TBAA in the actual swimming pool water is less than 2 ug/L. Under the background of the water matrix of the practical swimming pool, the four membrane materials have higher removal rate on five HAAs, and the total removal rate is more than 97 percent. The results show that the method is suitable for removing HAAs under the background of complex water quality matrixes, and is a method for removing HAAs in swimming pool water with simplicity, reliability and high efficiency.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A method for removing haloacetic acid substances in swimming pool water is characterized by comprising the following steps:
(1) membrane cleaning
Cutting a membrane material, soaking the membrane material in a glass bottle containing deionized water for 24 hours, taking out and cleaning the membrane material for later use;
(2) nanofiltration/reverse osmosis system cleaning
Starting a nanofiltration/reverse osmosis system, cleaning the membrane system by using deionized water under low pressure, and installing a membrane in a membrane pool after cleaning;
(3) nanofiltration/reverse osmosis system operation
Adding actual swimming pool water or simulated swimming pool water into a water storage tank, adjusting temperature, pressure and flow, and sampling after the system runs stably;
sample detection
(4) The method for detecting the haloacetic acid is based on detection by Gas Chromatography Mass Spectrometry (GCMS) after liquid-liquid extraction derivatization treatment of a water sample proposed by EPA 552.3.
2. The removal method according to claim 1, wherein the membrane material of step (1) is four kinds
Common commercial flat nanofiltration/reverse osmosis membranes comprise two nanofiltration membranes (NF90 and NF270) and two reverse osmosis membranes (XLE and SB50), wherein the membrane cutting size is 5 cm multiplied by 10 cm;
the conductivity of the deionized water is less than 0.4 mu s/cm;
the glass bottle is a 250 mL brown reagent bottle with a screw plug;
the cleaning refers to washing with deionized water for 4-5 times to remove impurities detached from the surface of the membrane after soaking.
3. The removal method of claim 1, wherein the nanofiltration/reverse osmosis of step (2)
The system is a device which consists of four identical rectangular cross-flow diaphragm tanks, a water storage tank, a booster pump, a water cooler and other equipment and can accurately regulate and control temperature, pressure and flow;
the low pressure is 0.2 bar;
the cleaning is to remove the impurities remained in the system, the cleaning time is 10 min each time, and the cleaning is carried out for 2-3 times.
4. The removal method according to claims 1 and 3, wherein the effective area of the membrane in the rectangular cross-flow membrane pool in the step (2) is 42 cm2(4.6 cm multiplied by 9.2 cm), a diaphragm gasket with the thickness of 1.2 mm is additionally arranged in each diaphragm tank;
the volume of the water storage tank is 30L, the water storage tank is made of stainless steel, and penetrating fluid and concentrated solution can completely flow back into the water storage tank to keep constant water inlet concentration;
the temperature is regulated by using a temperature control knob, the water chiller operates to maintain the constant temperature of the system, and the temperature of the system is displayed by a thermometer;
the pressure regulation and control means that a pressure knob is used for regulating the pressure, the booster pump operates to maintain the constant pressure of the system, and the pressure of the system is displayed by a pressure gauge connected to each pipeline;
the flow regulation and control means that the flow valve connected to each pipeline is used for regulating the flow, and the system flow is displayed by the flow meter connected to each pipeline.
5. The removal method as claimed in claim 1, wherein the swimming pool water in step (3) is taken from an indoor swimming pool normally operated in a certain urban district, the effective volume is 20L, and the water sample is ready to be taken;
the configuration simulation swimming pool water is configured based on the concentration and salinity of HAAs contained in the actual swimming pool water, only haloacetic acid and sodium chloride are added, other components are not added to eliminate the interference of other matrixes, and the effective volume is 20L;
the stable system means that the temperature, the pressure and the flow do not change along with the time after the system runs for at least 8 hours, the system is in a stable state, and the membrane flux is kept constant.
6. The removal method according to claim 1, wherein the sampling port in step (3) is a permeate outlet port, and the water sample is stored in the sampling bottle in a sealed manner.
7. The removing method according to the claims 1 and 6, wherein the sampling bottle in the step (3) is a 40 mL brown glass bottle with a screw-top plug and a polytetrafluoroethylene gasket, and is washed with deionized water and dried for a plurality of times before sampling;
the sealed preservation is to store the water sample in a brown bottle, and the preservation time is less than 7 days below 4 ℃.
8. The removal method according to claim 1, wherein the liquid-liquid extraction in step (4) is a process of extracting haloacetic acid in water by using methyl tert-butyl ether;
the removal method of claim 1, wherein the derivatizing of step (4) is performed by using acidic methanol to produce a haloacetic acid derivative product.
9. Further, the volume ratio of the acidic methanol to the methanol sulfuric acid is 1: 10, in water.
10. The removal method of claim 1, wherein the object of the GCMS detection analysis in step (4) is methylated haloacetic acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210082522.5A CN114349121A (en) | 2022-01-24 | 2022-01-24 | Method for removing haloacetic acid substances in swimming pool water |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210082522.5A CN114349121A (en) | 2022-01-24 | 2022-01-24 | Method for removing haloacetic acid substances in swimming pool water |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114349121A true CN114349121A (en) | 2022-04-15 |
Family
ID=81092497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210082522.5A Pending CN114349121A (en) | 2022-01-24 | 2022-01-24 | Method for removing haloacetic acid substances in swimming pool water |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114349121A (en) |
-
2022
- 2022-01-24 CN CN202210082522.5A patent/CN114349121A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5600864B2 (en) | Operation method of reverse osmosis membrane filtration plant and reverse osmosis membrane filtration plant | |
| Yu et al. | Degradation of diclofenac by advanced oxidation and reduction processes: kinetic studies, degradation pathways and toxicity assessments | |
| JP4765843B2 (en) | Seawater desalination method | |
| Seitz et al. | Removal of iodinated X-ray contrast media during drinking water treatment | |
| Molinari et al. | Studies on interactions between membranes (RO and NF) and pollutants (SiO2, NO3−, Mn++ and humic acid) in water | |
| Fan et al. | Removal of organic matter and disinfection by-products precursors in a hybrid process combining ozonation with ceramic membrane ultrafiltration | |
| Hidalgo et al. | Behaviour of RO90 membrane on the removal of 4-nitrophenol and 4-nitroaniline by low pressure reverse osmosis | |
| Kveštak et al. | Biotransformation of nonylphenol polyethoxylate surfactants by estuarine mixed bacterial cultures | |
| US5282967A (en) | Method for feeding germ-free pure water | |
| Winfield | The treatment of sewage effluents by reverse osmosis—pH based studies of the fouling layer and its removal | |
| CN114349121A (en) | Method for removing haloacetic acid substances in swimming pool water | |
| Ali et al. | The production of brominated methanes in desalination plants in Kuwait | |
| KR20140099772A (en) | Method and apparatus for continuous removal of perchlorate and nitrate by using halotolerant microorganisms | |
| Bott | Ozone as a disinfectant in process plant | |
| Al Sakiti et al. | Removal of di-2-ethyl hexyl phthalates by membrane bioreactor | |
| CN111138012A (en) | Plateau water filtering system | |
| JPS6336890A (en) | Apparatus for producing high-purity water | |
| CN115970499A (en) | Reverse osmosis system control method and device, electronic equipment and storage medium | |
| CN110860210A (en) | Reverse osmosis membrane alkaline cleaning agent and application thereof | |
| CN211644929U (en) | Plateau water filtering system | |
| Begum et al. | Biodegradation of phthalic acid esters by bakery yeast Saccharomyces cerevisiae. | |
| Manzak et al. | Extraction of acetic acid from aqueous solutions by emulsion type liquid membranes using Alamine 300 as a carrier | |
| WO2001010541A9 (en) | An apparatus and method for improving an osmosis process | |
| JPS58119304A (en) | Treatment of osmotic membrane | |
| CN101717166A (en) | Method for treating pharmaceutical wastewater |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |