What Is Geothermal Water?

Geothermal water refers to groundwater with surrounding rock temperatures above the observed depth. The temperature at which water begins to boil under a certain pressure is called the saturation temperature. The greater the geothermal water burial depth, the higher the static pressure, and the higher the corresponding saturation temperature.

Temperature in

The experimental results show that many domestic geothermal wells have high levels of fluorine in geothermal water, generally between 0.5 and 17 mg / l, up to 40 mg / l (the national standard for drinking water quality is 1.0 mg / l). ; Use of geothermal water for fish farming, when the fluorine content in the local hot water is higher than 1.0mg / l, the fluoride content in the fish body is higher than 2.0mg / kg, which exceeds the requirements of national food hygiene standards.

The geothermal water test results are compared with China's "Standard for Drinking Natural Mineral Water" GB8537-1995. Color, odor and taste indicators exceed the standard limits, do not meet hygienic requirements, and cannot be used as drinking.

According to the national "medical hot mineral water quality standards", the fluorine, arsenic, bromine, iodine, metasilicic acid, metaboric acid and other components in geothermal water have reached medically valuable concentrations. The names of mineral water can be named: fluorine water, silicon Water, arsenic water, bromine water, iodine water, boron water, etc. ^[1]

Geothermal resources are a valuable natural asset. It can be used as a heat source, water source and mineral resources, such as power generation, heating, showering and fish farming, etc., and is of great significance to the development of the national economy. China is rich in geothermal resources and is one of the earliest countries in the world to develop and utilize geothermal resources. The use of hot springs to treat certain diseases has a long history in China. At present, more than 20 provinces, municipalities and autonomous regions in China have carried out general surveys, exploration and comprehensive utilization of geothermal resources. In Beijing alone, more than 20 units use geothermal water for heating, washing, dyeing, showering, fish farming and swimming. Wait.

Medical effects of several chemical components in geothermal water

China has only minimum requirements for the content of special chemical components in bath mineral water, but no upper limit. For example, in China, arsenic must be> 0.7 mg / L before it can be called arsenic water and it has therapeutic effect. According to the former Soviet Union's classification of arsenic for bath mineral water: 0.7 to 5.0 mg / L is low and medium concentration arsenic bath mineral water; 5.0 to 10.0 mg / L is high concentration arsenic bath mineral water;> 10.0 mg / L is extremely high concentration The arsenic bath is treated with mineral water, and the objects and times for bath treatment with different concentrations of arsenic water are different.

Iodine: Iodine can strengthen the body's immune function, improve metabolism, regulate endocrine, especially thyroid function; and can expand blood vessels, lower blood pressure, improve weak eye circulation, promote the absorption of inflammatory exudates, soften scars and tissue regeneration; on the skin The mucous membrane has antiseptic and bactericidal effects.

Bathing indications: hyperthyroidism, arteriosclerosis, rheumatoid arthritis, menstrual disorders, skin diseases, etc.

Bromine: Bromine has inhibitory and sedative effects on the central nervous system.

Indications for bathing: neurosis, neuralgia, insomnia, hypertension, etc.

(3) Arsenic: Arsenic can promote the hematopoietic function of the bone marrow, reduce the level of metabolism, and increase the glycogen storage in the liver and muscle. Bathing can make the skin plumper, subcutaneous fat can be sterilized and sterilized.

Bathing indications: skin lupus erythematosus, fungal disease, scabies, nodular prurigo, etc.

Metasilicic acid: Bath has a cleansing and anti-inflammatory effect on human skin and mucous membranes. Give skin a soapy and fatty-like lubricity.

Bath indications: eczema, psoriasis,

Geothermal water is a collective term, but the specific classification is different, and geothermal water at different depths is suitable for drinking. Due to the specific conditions in different regions, the depth of development of suitable drinking is different. Here is an example:

Kaifeng City is located in the central and southern part of the North China Plain. The tectonic unit belongs to the southeast of Kaifeng Sag, the source of Jiyuan. The deep groundwater resources in the territory are relatively scarce. According to the information currently available, although there are seven deep groundwater reservoirs with development value within the depth of 300 to 2600 meters in the Kaifeng Sag, there are currently freshwater reservoirs of 300 to 1400 meters in development and utilization. According to calculations, when the water level drops by 50 meters, the recoverable amount of deep groundwater is only 90,000 cubic meters per day, and when the depth is 80 meters, it is only 150,000 cubic meters per day.

The temperature of deep groundwater is generally between 25 ° C and 53 ° C. The water contains a variety of trace elements that are beneficial to the human body. It is an ideal drinking water and bath water. At present, geothermal water is the only uncontaminated water resource in Kaifeng City, and it is a "children's water" that plays a very important role in maintaining long-term water safety in Kaifeng City. However, the geothermal water in Kaifeng City is a non-renewable "basin of dead water", and its storage capacity is limited. Use a little less, and measures must be taken to protect it and development must be strictly controlled.

Therefore, the harmful rumors of geothermal water circulating on the Internet need to be screened and cannot be generalized. You can ask the geothermal developer if you can drink it, because it should have a drinkability test report before development.

Problems in the use of geothermal water

Corrosion of geothermal utilization equipment

1.Corrosion and hazards of geothermal water

Geothermal water corrosion is a common problem in geothermal development and utilization. Geothermal water corrosion is usually related to its own chemical composition, pipeline materials, system operating environment and operating parameters. Geothermal water contains a variety of chemical components, which have a significant impact on the corrosion of metal materials. Among the main components that cause corrosion are O ₂ , H ⁺ , CI ^a ,

, H ₂ S, CO ₂ and so on, these materials can chemically and electrochemically corrode with metal materials. Because of geothermal water

Geothermal water is a precious liquid mineral resource. It is a good non-drinking medical mineral water and has medical care value. Because the geothermal water renewal cycle is very long, it is difficult to recover in the short term. It must be developed and used reasonably and adhere to sustainable development. ^[1]