1. What is domestic water？ Domestic water is the general term of water used in human daily life and related activities。In the city, including residential water, municipal public water, environmental sanitation and green water and building water;Including water for people and animals in rural areas。The standard of domestic water consumption is measured by person, and the unit is liter/person · day。 2. Classification of domestic water Domestic water can be divided into two categories: urban domestic water and rural domestic water。 2.1. Urban domestic water 居民...

01, the origin of tap water The water supply of our city began in 1874, and the Longan Spring underground water supply facility was first built in Lushunkou, which has a history of 125 years。For a long time, tap water has never been doubted as drinking water for city residents, so is tap water safe？ 02, China's tap water low standard qualified In the early 1970s, the United States first found that water contains trihalomethane, and proved that the substance has a carcinogenic effect on the human body。As China's groundwater and surface water pollution intensifies, tap water...

What is the TDS value？ TDS, short for Total dissolved solids, means all dissolved solids。It is used to describe the content of inorganic salts and organic matter in water, mainly including cations such as calcium, magnesium, sodium and potassium, as well as anions such as carbonate, bicarbonate, chloride, sulfate and nitrate。 The simplest way to detect the TDS value is to use the TDS pen to measure it。The probe of the TDS detector pen has positive and negative electrodes, which can determine the soluble particles in the water according to the different conductivity of soluble substances in the water...

Since the beginning of this century, with the rapid development of modern industry, a large number of discharge of all kinds of wastewater, the natural water system has been significantly polluted, the water quality has generally declined, and the fresh water available for safe use is increasingly insufficient。 As far as our country is concerned，According to the Announcement of China's Ecological and Environmental Statistics Annual Report 2020，More than 60 billion tons of wastewater were discharged nationwide，Chemical oxygen demand emissions of about 25 million tons，Ammonia nitrogen emissions are nearly 1 million tons，Total nitrogen emissions are more than 3 million tons，Oil emissions were more than 3,700 tons，The emission of volatile phenol is nearly 60 tons，The cyanide discharge is about 42 tons，Heavy metal platoon...

1. How much water there is on the earth？ The total amount of water held by the Earth is about 13.6 billion tons, of which about 132 billion are salty sea water.200 million tons。Because of the salt content, sea water cannot be used as a source of water for life on land。The distribution of water on the earth is roughly as follows: oceans account for 97 percent.2%, with polar icebergs accounting for 2%.15%, groundwater accounted for 0.632%, lakes and rivers accounted for 0.017% of the cloud is water vapor.001%。 The fresh water on land comes from the sea。The sea water evaporates in the sun, the salt stays in the sea, and the fresh water evaporates into the sky, forming wet...