Summary of the invention
Technical problem to be solved by this invention is: household reverse osmosis pure water in order to avoid fouling membrane, has more concentrated water discharge in producing, and causes water to be wasted serious; The present invention solves mainly through pre-filtering means, and under can making the condition that outer water displacement is less, reverse osmosis membrane still has good flux and keeps.
Technical scheme:
A kind of saving type RO pure water production method, comprises the steps: by tap water first through quartz sand filtration process, then carries out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into reverse osmosis membrane again and is carried out filtration treatment; Described absorbent filter medium is made up of the following component according to parts by weight: 20 ~ 40 parts, volcanics, modified activated carbon 120 ~ 150 parts, activated alumina 10 ~ 20 parts, kaolin clay 10 ~ 20 parts, Zeo-karb 5 ~ 10 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 60 ~ 80 parts, be ground into smalls, then mix with the alcoholic solvent of the sodium hydroxide of 20 ~ 25 parts, 10 ~ 20 parts, water and 20 ~ 30 parts; Then mixture is placed in tube furnace, under the atmosphere of rare gas element, heat up charing, carries out ball milling after letting cool, then wash with citric acid solution, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
Described alcoholic solvent is the mixture of one or more in methyl alcohol, ethanol, propyl alcohol, isopropylcarbinol, propyl carbinol.
Described rare gas element refers to argon gas, helium or nitrogen.
The parameter of carbonization is: temperature rise rate 5 ~ 10 DEG C/min, carbonization temperature 1100 ~ 1200 DEG C, carbonization time 3 ~ 5 hours.
The mass concentration of described citric acid solution is 1 ~ 10%.
The material of described reverse osmosis membrane is cellulose acetate.
Reverse osmosis membrane is in filtration procedure, and pressure is 0.1 ~ 0.5Mpa.
The flux of the product water of reverse osmosis is 10 ~ 30L/m2h, it is produce volume of water 1/3 ~ 1/2 that the concentrated water drainage of reverse osmosis goes out volume.
beneficial effect
The present invention carries out pre-treatment by filter sand to the water quality of tap water, when can remain on less reverse osmosis concentrated water discharge, keeps the flux of reverse osmosis membrane.
Embodiment
The particulate filter that volcanics processes through series of process such as ore dressing, fragmentation, screening, grindings, its major ingredient is tens kinds of mineral substance and the trace elements such as silicon, aluminium, calcium, sodium, magnesium, titanium, manganese, iron, nickel, cobalt and molybdenum, apparent is irregular particle, color is red-black brown, porous light weight, grain diameter can require to produce according to difference.Volcanics shows as in physics microtexture: the many micropores of surface irregularity, and these features are particularly suitable for microorganism in its surface growth, breeding, forms microbial film.Volcanics filtrate makes BAF process municipal wastewater, and organic industrial sewage, living drainage, micro-polluted source water etc. that can be biochemical, also can replace quartz sand, gac, hard coal etc. and be used as filtration medium in Water purification, also can do advanced treatment to the tail water after sewage work's second-stage treatment technique simultaneously, after its process water outlet reaches recycle water standard, can Treated sewage reusing be made.
Activated alumina, has another name called activated alumina.Use usually specially being called " activated alumina " of aluminum oxide in the catalyst, it is the solid material of a kind of porousness, high degree of dispersion, there is very large surface-area, its micropore surface possesses the characteristic required by katalysis, as absorption property, surfactivity, excellent thermostability etc., so be widely used as catalyzer and the support of the catalyst of chemical reaction.In the present invention, activated alumina preferably adopts and meets the Ministry of Chemical Industry of People's Republic of China (PRC) standard: HG/T3927-2007.
Modified activated carbon, can improve the absorption to impurities in water, colloid etc. from the beginning effectively.The Main Function of Zeo-karb removes calcium, the magnesium plasma in water, prevents the fouling of reverse osmosis membrane.
Embodiment 1
By tap water first through quartz sand filtration process, then carry out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into cellulose acetate reverse osmosis film again and is carried out filtration treatment; Reverse osmosis membrane is in filtration procedure, and pressure is 0.3Mpa, and it is produce volume of water 1/3 that the concentrated water drainage of reverse osmosis goes out volume; Described absorbent filter medium is made up of the following component according to parts by weight: 20 parts, volcanics, modified activated carbon 120 parts, activated alumina 10 parts, kaolin clay 10 parts, Zeo-karb 5 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 60 parts, be ground into smalls, then mix with the ethanol of the sodium hydroxide of 20 parts, 10 parts, water and 20 parts; Then mixture is placed in tube furnace, in a nitrogen atmosphere, heat up charing, and the parameter of carbonization is: temperature rise rate 10 DEG C/min, carbonization temperature 1200 DEG C, carbonization time 3 hours; Carry out ball milling after letting cool, then be the citric acid solution washing of 5% by mass concentration, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
Embodiment 2
By tap water first through quartz sand filtration process, then carry out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into cellulose acetate reverse osmosis film again and is carried out filtration treatment; Reverse osmosis membrane is in filtration procedure, and pressure is 0.3Mpa, and it is produce volume of water 1/3 that the concentrated water drainage of reverse osmosis goes out volume; Described absorbent filter medium is made up of the following component according to parts by weight: 40 parts, volcanics, modified activated carbon 150 parts, activated alumina 20 parts, kaolin clay 20 parts, Zeo-karb 10 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 80 parts, be ground into smalls, then mix with the ethanol of the sodium hydroxide of 25 parts, 20 parts, water and 30 parts; Then mixture is placed in tube furnace, in a nitrogen atmosphere, heat up charing, and the parameter of carbonization is: temperature rise rate 10 DEG C/min, carbonization temperature 1200 DEG C, carbonization time 5 hours; Carry out ball milling after letting cool, then be the citric acid solution washing of 5% by mass concentration, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
Embodiment 3
By tap water first through quartz sand filtration process, then carry out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into cellulose acetate reverse osmosis film again and is carried out filtration treatment; Reverse osmosis membrane is in filtration procedure, and pressure is 0.3Mpa, and it is produce volume of water 1/3 that the concentrated water drainage of reverse osmosis goes out volume; Described absorbent filter medium is made up of the following component according to parts by weight: 30 parts, volcanics, modified activated carbon 130 parts, activated alumina 15 parts, kaolin clay 16 parts, Zeo-karb 8 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 70 parts, be ground into smalls, then mix with the ethanol of the sodium hydroxide of 22 parts, 15 parts, water and 25 parts; Then mixture is placed in tube furnace, in a nitrogen atmosphere, heat up charing, and the parameter of carbonization is: temperature rise rate 7 DEG C/min, carbonization temperature 1150 DEG C, carbonization time 4 hours; Carry out ball milling after letting cool, then be the citric acid solution washing of 5% by mass concentration, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
Reference examples 1
Be with the difference of embodiment 3: in the preparation of modified activated carbon, do not add sodium hydroxide.
By tap water first through quartz sand filtration process, then carry out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into cellulose acetate reverse osmosis film again and is carried out filtration treatment; Reverse osmosis membrane is in filtration procedure, and pressure is 0.3Mpa, and it is produce volume of water 1/3 that the concentrated water drainage of reverse osmosis goes out volume; Described absorbent filter medium is made up of the following component according to parts by weight: 30 parts, volcanics, modified activated carbon 130 parts, activated alumina 15 parts, kaolin clay 16 parts, Zeo-karb 8 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 70 parts, be ground into smalls, then mix with the ethanol of 15 parts, water and 25 parts; Then mixture is placed in tube furnace, in a nitrogen atmosphere, heat up charing, and the parameter of carbonization is: temperature rise rate 7 DEG C/min, carbonization temperature 1150 DEG C, carbonization time 4 hours; Carry out ball milling after letting cool, then be the citric acid solution washing of 5% by mass concentration, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
Reference examples 2
Be with the difference of embodiment 3: in the preparation of modified activated carbon, do not add water.
By tap water first through quartz sand filtration process, then carry out filtration treatment in product water feeding absorbent filter medium sand filtration obtained; The water outlet of absorbent filter medium is sent into cellulose acetate reverse osmosis film again and is carried out filtration treatment; Reverse osmosis membrane is in filtration procedure, and pressure is 0.3Mpa, and it is produce volume of water 1/3 that the concentrated water drainage of reverse osmosis goes out volume; Described absorbent filter medium is made up of the following component according to parts by weight: 30 parts, volcanics, modified activated carbon 130 parts, activated alumina 15 parts, kaolin clay 16 parts, Zeo-karb 8 parts;
Described modified activated carbon prepares by the following method:
By weight, get coconut palm shell fiber 70 parts, be ground into smalls, then mix with sodium hydroxide part of 22 parts and the ethanol of 25 parts; Then mixture is placed in tube furnace, in a nitrogen atmosphere, heat up charing, and the parameter of carbonization is: temperature rise rate 7 DEG C/min, carbonization temperature 1150 DEG C, carbonization time 4 hours; Carry out ball milling after letting cool, then be the citric acid solution washing of 5% by mass concentration, then with pure water to neutral, after oven dry, grind, obtain modified activated carbon.
The water quality situation of the tap water adopted in above embodiment and reference examples is as follows:
| Index | Water quality |
| pH | 7.4 |
| SS mg/L | 57 |
| Hardness mg/L | 163.4 |
| COD mg/L | 17 |
| Specific conductivity μ s/cm | 1482 |
The regimen of aquatic products from the beginning condition is after treatment as follows, in addition, controls the working time of reverse osmosis membrane at 20 hours, then record runs the reverse osmosis membrane flux situation of front and back:
As can be seen from the table, when being high-volume 1/3 operation of producing water quantity discharged adopting concentrated water drainage, process for preparing water provided by the invention still can keep the water quality of the good flux of reverse osmosis membrane and product water after 20 hours; Owing to not adding NaOH in the preparation process of gac in reference examples 1, cause to form good microscopic spaces in the structure of gac, had influence on adsorption effect; Owing to not adding water in reference examples 2, the dispersiveness that result in NaOH is bad, has had influence on it and has expanded the effect in activated carbon capillary.