It is reported that Shanghai conducted a sampling water quality, the unqualified rate reached 40%, what causes the water passing rate so low?
This is first caused by technological reasons. At present, a lot of daily necessities are made of copper, iron, stainless steel and other materials. All these materials contain heavy metals. If they are not handled properly, they may cause excessive standards.
For example, the main elements of stainless steel include manganese, chromium, and nickel. In order to maintain corrosion resistance, stainless steel must contain a certain amount of chromium. If chromium is not treated properly, it may cause chromium to exceed the standard. In the same way, the improper treatment of manganese may lead to the excess of manganese.
In the copper alloy made of the faucet, the metal elements such as iron, aluminum and lead are contained in the copper alloy. If there is no lead, it is difficult to form when casting. The higher the lead content is, the easier the casting process is, so the copper tap on the market usually contains a certain amount of lead. If the factory is in the manufacture, the lead removal process is not good, which will cause the lead to exceed the standard.
Another reason is that the technology and equipment of the enterprise are aging, which leads to the lack of control of the trace elements. Usually, when new equipment is put into production, the product is qualified, but when the equipment is used for a long time, the product will exceed the standard. This situation can not be repaired from a technical point of view, and can only replace new equipment, but some factories continue to use to save money, which is a technical problem as well as a cost problem.
A distributor of bathroom equipment told reporters that most of the water faucets in the market are copper core, but the quality is different. Small manufacturers, cheap faucets, lead more than the possibility of lead. This is because some manufacturers, in order to control the cost, do not buy standard brass alloys, but buy cheap lead brass as raw materials from small workshops. The lead brass often has high lead content, but the price is only half of the brass alloy.
