What is the difference between pure drinking water and mineral water and what process is used?

Drinking pure water and mineral water are two kinds of water commonly consumed in daily life; mineral water has more mineral content and will be complementary to the body’s trace elements; pure water does not contain any minerals.

Pure water is the natural water through multiple processes of processing, purification, and purification of water; mineral water is naturally gushing from deep underground or is artificially collected, uncontaminated underground mineral water.”

What are the differences between these two types of water and what processes are used?

Implementation standards

1, Pure water quality in line with the national “drinking water quality standards” CJ94-2005, or to meet the national “bottled (barrel) drinking water hygiene standards” GB17324-2003

2, Mineral water quality in line with the national GB 8537-2018 “national food safety standards for natural mineral water for drinking

The Water Source

1, Pure water source requirements are not high, you can make tap water, lake water, groundwater, seawater, or even reuse water.

The content of trichloromethane and carbon tetrachloride in pure drinking water shall not exceed 0.02mg/L and 0.001mg/L, respectively.

2, The natural mineral water source requirements are relatively high, needs to be from deep underground natural outpouring or artificially exposed, uncontaminated underground mineral water;
Contains a certain amount of mineral salts: trace elements or carbon dioxide gas;
In general, its chemical composition, flow, water temperature, and other dynamics in the natural fluctuation range is relatively stable.

The nine boundary indicators specified in the national standards include lithium, strontium, zinc, selenium, bromide, iodide, metasilicic acid, free carbon dioxide, and total dissolved solids.

Mineral water must have one or more to meet the requirements of the boundary indicators, the requirements of the content are (unit: mg / L): lithium, zinc, iodide are ≥ 0.2, selenium ≥ 0.01, bromide ≥ 1.0, metasilic acid ≥ 25, free Most of the mineral water on the market belongs to strontium (Sr) and metasilicicic acid type.

Process

1, The main process of pure water electrodialysis, ion exchanger method, reverse osmosis, distillation method, the current mainstream method is reverse osmosis method.

①, The electrodialysis method is the use of the electric field, forcibly attractions to the electrode, resulting in the electrode in the middle of the ion concentration is greatly reduced, so as to produce fresh water.

②, Ion exchanger method ion exchange method is a salt removal method that uses a strong acidic hydrogen type resin to remove various cations (except hydrogen) from water, and then a strongly alkaline hydroxide type anion exchange resin to remove various anions (except hydroxide ions) from water.

③ The reverse osmosis method can remove more than 90 % of dissolved salts and more than 99 % of colloidal microorganisms and organic matter from water.

In particular, the reverse osmosis purification brackish water device powered by wind and solar energy is an economic and reliable way to solve the problem of people’s living water in areas without electricity and conventional energy shortage.

The reverse osmosis desalination method is not only applicable to seawater desalination but also suitable for brackish water desalination. Among the existing desalination methods, reverse osmosis desalination is the most economical, and it has even surpassed electrodialysis desalination.

Since the driving force of the reverse osmosis process is pressure, no phase change occurs during the process, and the membrane only plays the role of “sieving”, the energy consumption required for the separation process of reverse osmosis is low.

Among the existing desalination of seawater and brackish water, reverse osmosis is the most energy-efficient method. The characteristic of reverse osmosis membrane separation is its “broad-spectrum” separation, i.e. it can remove not only various ions in water but also particles larger than ions, such as most organic matter, colloids, viruses, bacteria, suspended matter, etc.

④, Distillation method to distill and condense water, steamed twice is called redistilled water and steamed three times is called triple distilled water.

Sometimes for special purposes, before steaming will add appropriate reagents, such as order to no ammonia, will add acid to the water;
Low oxygen consumption of water, add potassium permanganate with acid, etc.

Industrial distilled water is the use of distilled water method to obtain pure water, generally ordinary distillation of water obtained the purity is not high, after multi-stage distillation of water, the water can reach very pure, and the cost is relatively high.

2, The main process of mineral water are ultrafiltration and nanofiltration, the current more mainstream method is ultrafiltration.

①, The ultrafiltration method uses the microporous structure of the semi-permeable membrane, with a certain external pressure (0.1 ~ 0.5 MPa) as the driving force to achieve selective separation of substances, and recovery of membrane separation methods.

It is mainly used in wastewater treatment to separate macromolecules and colloids with molecular weights greater than 500 and diameters of 0.005 to 10 μm, such as enzymes, proteins, viruses, and other low and medium concentrations of macromolecular dissolved state and colloidal state pollutants for separation and recovery.

Ultrafiltration (UF) technology is a membrane separation technology between microfiltration and nanofiltration, with an average pore size of 3~100 nm, which has the functions of purification, separation, and concentration of solutions.

Its retention mechanism mainly includes membrane sieving and electrostatic effect, the filtration medium is an ultrafiltration membrane, driven by the pressure difference between the two sides, only low molecular weight solutes and water can pass through the ultrafiltration membrane, so as to achieve the purpose of purification, separation, and concentration.

②, Nanofiltration can effectively filter out organic pollutants such as antibiotics, hormones, pesticides, petroleum, detergents, algae toxins, harmful heavy metal ions such as lead, cobalt, antimony, mercury, cadmium, chromium, and most of the scale, while other mineral ions pass through more easily.

Therefore, the nanofiltration water purifier removes pollutants while retaining minerals in the water that are beneficial to humans.

Nanofiltration membrane: with a pore size of 1nm or more, generally 1-2nm, is a functional semi-permeable membrane that allows solvent molecules or certain low molecular weight solutes or low-valued ions to pass through.

It is a special and promising variety of separation membranes, named for its ability to retain substances of approximately nanometer size.

It is used to remove organic matter and color from surface water, to remove hardness from groundwater, to partially remove dissolved salts, to concentrate fruit juices, and to separate useful substances from pharmaceuticals.

Water is the source of life, water does play a vital role in maintaining the body’s digestion, excretion, circulation, regulation of body temperature, lubrication, metabolism, and other physiological functions.

Our life is closely related to understanding the difference between drinking pure water and drinking mineral water, which is conducive to our daily choice of appropriate drinking water resources!